The pattern of any process, or the interrelationship of phenomena, which affects growth or change within a population.
Number of individuals in a population relative to space.
A functional system which includes the organisms of a natural community together with their environment. (McGraw Hill Dictionary of Scientific and Technical Terms, 4th ed)
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
Divisions of the year according to some regularly recurrent phenomena usually astronomical or climatic. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Increase, over a specific period of time, in the number of individuals living in a country or region.
The longterm manifestations of WEATHER. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
A computer simulation developed to study the motion of molecules over a period of time.
Computer-based representation of physical systems and phenomena such as chemical processes.
The branch of science concerned with the interrelationship of organisms and their ENVIRONMENT, especially as manifested by natural cycles and rhythms, community development and structure, interactions between different kinds of organisms, geographic distributions, and population alterations. (Webster's, 3d ed)
Theoretical representations that simulate the behavior or activity of systems, processes, or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.
The total process by which organisms produce offspring. (Stedman, 25th ed)
The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.
Processes that incorporate some element of randomness, used particularly to refer to a time series of random variables.
The external elements and conditions which surround, influence, and affect the life and development of an organism or population.
The study of systems which respond disproportionately (nonlinearly) to initial conditions or perturbing stimuli. Nonlinear systems may exhibit "chaos" which is classically characterized as sensitive dependence on initial conditions. Chaotic systems, while distinguished from more ordered periodic systems, are not random. When their behavior over time is appropriately displayed (in "phase space"), constraints are evident which are described by "strange attractors". Phase space representations of chaotic systems, or strange attractors, usually reveal fractal (FRACTALS) self-similarity across time scales. Natural, including biological, systems often display nonlinear dynamics and chaos.
The science dealing with the earth and its life, especially the description of land, sea, and air and the distribution of plant and animal life, including humanity and human industries with reference to the mutual relations of these elements. (From Webster, 3d ed)
Invertebrates or non-human vertebrates which transmit infective organisms from one host to another.
Periodic movements of animals in response to seasonal changes or reproductive instinct. Hormonal changes are the trigger in at least some animals. Most migrations are made for reasons of climatic change, feeding, or breeding.
The relationship between an invertebrate and another organism (the host), one of which lives at the expense of the other. Traditionally excluded from definition of parasites are pathogenic BACTERIA; FUNGI; VIRUSES; and PLANTS; though they may live parasitically.
Instinctual behavior pattern in which food is obtained by killing and consuming other species.
The continuous sequence of changes undergone by living organisms during the post-embryonic developmental process, such as metamorphosis in insects and amphibians. This includes the developmental stages of apicomplexans such as the malarial parasite, PLASMODIUM FALCIPARUM.
A large, subclass of arachnids comprising the MITES and TICKS, including parasites of plants, animals, and humans, as well as several important disease vectors.
A subfamily of MURIDAE found nearly world-wide and consisting of about 20 genera. Voles, lemmings, and muskrats are members.
The relationships of groups of organisms as reflected by their genetic makeup.
Genotypic differences observed among individuals in a population.
Water particles that fall from the ATMOSPHERE.
Places for cultivation and harvesting of fish, particularly in sea waters. (from McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The discipline studying genetic composition of populations and effects of factors such as GENETIC SELECTION, population size, MUTATION, migration, and GENETIC DRIFT on the frequencies of various GENOTYPES and PHENOTYPES using a variety of GENETIC TECHNIQUES.
The protection, preservation, restoration, and rational use of all resources in the total environment.
The sequence of transfers of matter and energy from organism to organism in the form of FOOD. Food chains intertwine locally into a food web because most organisms consume more than one type of animal or plant. PLANTS, which convert SOLAR ENERGY to food by PHOTOSYNTHESIS, are the primary food source. In a predator chain, a plant-eating animal is eaten by a larger animal. In a parasite chain, a smaller organism consumes part of a larger host and may itself be parasitized by smaller organisms. In a saprophytic chain, microorganisms live on dead organic matter.
A plant genus of the family Plantaginaceae. Members contain bis-sesquiterpene and iridoid glucosides.
Elements of limited time intervals, contributing to particular results or situations.
The reduction or regulation of the population of noxious, destructive, or dangerous plants, insects, or other animals. This includes control of plants that serve as habitats or food sources for animal pests.
The science that deals with the ocean and its phenomena. (Webster, 3d ed)
Minute free-floating animal organisms which live in practically all natural waters.
A monocot family within the order Liliales. This family is divided by some botanists into other families such as Convallariaceae, Hyacinthaceae and Amaryllidaceae. Amaryllidaceae, which have inferior ovaries, includes CRINUM; GALANTHUS; LYCORIS; and NARCISSUS and are known for AMARYLLIDACEAE ALKALOIDS.
The state of the ATMOSPHERE over minutes to months.
The ceasing of existence of a species or taxonomic groups of organisms.
Any of several large carnivorous mammals of the family CANIDAE that usually hunt in packs.
Free-floating minute organisms that are photosynthetic. The term is non-taxonomic and refers to a lifestyle (energy utilization and motility), rather than a particular type of organism. Most, but not all, are unicellular algae. Important groups include DIATOMS; DINOFLAGELLATES; CYANOBACTERIA; CHLOROPHYTA; HAPTOPHYTA; CRYPTOMONADS; and silicoflagellates.
The capacity to conceive or to induce conception. It may refer to either the male or female.
The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.
The inter- and intra-relationships between various microorganisms. This can include both positive (like SYMBIOSIS) and negative (like ANTIBIOSIS) interactions. Examples include virus - bacteria and bacteria - bacteria.
Statistical formulations or analyses which, when applied to data and found to fit the data, are then used to verify the assumptions and parameters used in the analysis. Examples of statistical models are the linear model, binomial model, polynomial model, two-parameter model, etc.
Any of several carnivores in the family CANIDAE, that possess erect ears and long bushy tails and are smaller than WOLVES. They are classified in several genera and found on all continents except Antarctica.
The process of laying or shedding fully developed eggs (OVA) from the female body. The term is usually used for certain INSECTS or FISHES with an organ called ovipositor where eggs are stored or deposited before expulsion from the body.
Any significant change in measures of climate (such as temperature, precipitation, or wind) lasting for an extended period (decades or longer). It may result from natural factors such as changes in the sun's intensity, natural processes within the climate system such as changes in ocean circulation, or human activities.
Infections or infestations with parasitic organisms. The infestation may be experimental or veterinary.
Frozen water crystals that fall from the ATMOSPHERE.
Insects that transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.
The variety of all native living organisms and their various forms and interrelationships.
The spectrum of different living organisms inhabiting a particular region, habitat, or biotope.
Warm-blooded VERTEBRATES possessing FEATHERS and belonging to the class Aves.
A family of the order DIPTERA that comprises the mosquitoes. The larval stages are aquatic, and the adults can be recognized by the characteristic WINGS, ANIMAL venation, the scales along the wing veins, and the long proboscis. Many species are of particular medical importance.
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
Differential and non-random reproduction of different genotypes, operating to alter the gene frequencies within a population.
One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.
Water containing no significant amounts of salts, such as water from RIVERS and LAKES.
Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.
Behavioral responses or sequences associated with eating including modes of feeding, rhythmic patterns of eating, and time intervals.
Statistical interpretation and description of a population with reference to distribution, composition, or structure.
The relationship between two different species of organisms that are interdependent; each gains benefits from the other or a relationship between different species where both of the organisms in question benefit from the presence of the other.
Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.
Any of various ruminant mammals of the order Bovidae. They include numerous species in Africa and the American pronghorn.
The functions, behavior, and activities of bacteria.
The number of males per 100 females.
A huge subclass of mostly marine CRUSTACEA, containing over 14,000 species. The 10 orders comprise both planktonic and benthic organisms, and include both free-living and parasitic forms. Planktonic copepods form the principle link between PHYTOPLANKTON and the higher trophic levels of the marine food chains.
Marine, freshwater, or terrestrial mollusks of the class Gastropoda. Most have an enclosing spiral shell, and several genera harbor parasites pathogenic to man.
A theorem in probability theory named for Thomas Bayes (1702-1761). In epidemiology, it is used to obtain the probability of disease in a group of people with some characteristic on the basis of the overall rate of that disease and of the likelihood of that characteristic in healthy and diseased individuals. The most familiar application is in clinical decision analysis where it is used for estimating the probability of a particular diagnosis given the appearance of some symptoms or test result.
A suborder of the order ARTIODACTYLA whose members have the distinguishing feature of a four-chambered stomach, including the capacious RUMEN. Horns or antlers are usually present, at least in males.
Slender-bodies diurnal insects having large, broad wings often strikingly colored and patterned.
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
A family of the order DIPTERA with over 700 species. Important species that may be mechanical vectors of disease include Musca domesticus (HOUSEFLIES), Musca autumnalis (face fly), Stomoxys calcitrans (stable fly), Haematobia irritans (horn fly) and Fannia spp.
A family (Aphididae) of small insects, in the suborder Sternorrhyncha, that suck the juices of plants. Important genera include Schizaphis and Myzus. The latter is known to carry more than 100 virus diseases between plants.
The physical measurements of a body.
BEETLES in the family Curculionidae and the largest family in the order COLEOPTERA. They have a markedly convex shape and many are considered pests.
An order of the class Insecta. Wings, when present, number two and distinguish Diptera from other so-called flies, while the halteres, or reduced hindwings, separate Diptera from other insects with one pair of wings. The order includes the families Calliphoridae, Oestridae, Phoridae, SARCOPHAGIDAE, Scatophagidae, Sciaridae, SIMULIIDAE, Tabanidae, Therevidae, Trypetidae, CERATOPOGONIDAE; CHIRONOMIDAE; CULICIDAE; DROSOPHILIDAE; GLOSSINIDAE; MUSCIDAE; TEPHRITIDAE; and PSYCHODIDAE. The larval form of Diptera species are called maggots (see LARVA).
The direct struggle between individuals for environmental necessities or for a common goal.
Unstable isotopes of lead that decay or disintegrate emitting radiation. Pb atoms with atomic weights 194-203, 205, and 209-214 are radioactive lead isotopes.
Total mass of all the organisms of a given type and/or in a given area. (From Concise Dictionary of Biology, 1990) It includes the yield of vegetative mass produced from any given crop.
Fish of the genera ONCORHYNCHUS and Salmo in the family SALMONIDAE. They are anadromous game fish, frequenting the coastal waters of both the North Atlantic and Pacific. They are known for their gameness as a sport fish and for the quality of their flesh as a table fish. (Webster, 3d ed).
An order of BIRDS including over 300 species that primarily inhabit coastal waters, beaches, and marshes. They are comprised of shorebirds, gulls, and terns.
Woody, usually tall, perennial higher plants (Angiosperms, Gymnosperms, and some Pterophyta) having usually a main stem and numerous branches.
A phylum of bacteria comprised of three classes: Bacteroides, Flavobacteria, and Sphingobacteria.
A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.
A process by which animals in various forms and stages of development are physically distributed through time and space.
Ecosystem and environmental activities, functions, or events.
An animal or plant species in danger of extinction. Causes can include human activity, changing climate, or change in predator/prey ratios.
A genus of mosquitoes (CULICIDAE) frequently found in tropical and subtropical regions. YELLOW FEVER and DENGUE are two of the diseases that can be transmitted by species of this genus.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
INSECTS of the order Coleoptera, containing over 350,000 species in 150 families. They possess hard bodies and their mouthparts are adapted for chewing.
The reduction or regulation of the population of noxious, destructive, or dangerous insects through chemical, biological, or other means.
The prevention of growth and or spread of unwanted plants.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
The capability of an organism to survive and reproduce. The phenotypic expression of the genotype in a particular environment determines how genetically fit an organism will be.
Systems that provide for the maintenance of life in an isolated living chamber through reutilization of the material available, in particular, by means of a cycle wherein exhaled carbon dioxide, urine, and other waste matter are converted chemically or by photosynthesis into oxygen, water, and food. (NASA Thesaurus, 1988)
The simplest saturated hydrocarbon. It is a colorless, flammable gas, slightly soluble in water. It is one of the chief constituents of natural gas and is formed in the decomposition of organic matter. (Grant & Hackh's Chemical Dictionary, 5th ed)
The various physical methods which include wind, insects, animals, tension, and water, by which a plant scatters its seeds away from the parent plant.
A type of climate characterized by insufficient moisture to support appreciable plant life. It is a climate of extreme aridity, usually of extreme heat, and of negligible rainfall. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Enumeration by direct count of viable, isolated bacterial, archaeal, or fungal CELLS or SPORES capable of growth on solid CULTURE MEDIA. The method is used routinely by environmental microbiologists for quantifying organisms in AIR; FOOD; and WATER; by clinicians for measuring patients' microbial load; and in antimicrobial drug testing.
A variety of simple repeat sequences that are distributed throughout the GENOME. They are characterized by a short repeat unit of 2-8 basepairs that is repeated up to 100 times. They are also known as short tandem repeats (STRs).
Tools or devices for generating products using the synthetic or chemical conversion capacity of a biological system. They can be classical fermentors, cell culture perfusion systems, or enzyme bioreactors. For production of proteins or enzymes, recombinant microorganisms such as bacteria, mammalian cells, or insect or plant cells are usually chosen.
A great expanse of continuous bodies of salt water which together cover more than 70 percent of the earth's surface. Seas may be partially or entirely enclosed by land, and are smaller than the five oceans (Atlantic, Pacific, Indian, Arctic, and Antarctic).
Any arthropod of the subclass ACARI except the TICKS. They are minute animals related to the spiders, usually having transparent or semitransparent bodies. They may be parasitic on humans and domestic animals, producing various irritations of the skin (MITE INFESTATIONS). Many mite species are important to human and veterinary medicine as both parasite and vector. Mites also infest plants.
Activities performed by humans.
The family Cervidae of 17 genera and 45 species occurring nearly throughout North America, South America, and Eurasia, on most associated continental islands, and in northern Africa. Wild populations of deer have been established through introduction by people in Cuba, New Guinea, Australia, New Zealand, and other places where the family does not naturally occur. They are slim, long-legged and best characterized by the presence of antlers. Their habitat is forests, swamps, brush country, deserts, and arctic tundra. They are usually good swimmers; some migrate seasonally. (Walker's Mammals of the World, 5th ed, p1362)
A genus of the family BACULOVIRIDAE, subfamily Eubaculovirinae, characterized by ovicylindrical occlusion bodies. The type species is Cydia pomonella granulovirus.
A genus of mosquitoes (CULICIDAE) that are known vectors of MALARIA.
Fish-eating carnivores of the family MUSTELIDAE, found on both hemispheres.
A genus of marine mussels in the family MYTILIDAE, class BIVALVIA. The species MYTILUS EDULIS is the highly edible common mussel.
Constituent of 30S subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16S rRNA is involved in initiation of polypeptide synthesis.
A body of water covering approximately one-fifth of the total ocean area of the earth, extending amidst Africa in the west, Australia in the east, Asia in the north, and Antarctica in the south. Including the Red Sea and the Persian Gulf, it constitutes the third largest ocean after the ATLANTIC OCEAN and the PACIFIC OCEAN. (New Encyclopaedia Britannica Micropaedia, 15th ed, 1990, p289)
A field of study concerned with the principles and processes governing the geographic distributions of genealogical lineages, especially those within and among closely related species. (Avise, J.C., Phylogeography: The History and Formation of Species. Harvard University Press, 2000)
The presence of bacteria, viruses, and fungi in water. This term is not restricted to pathogenic organisms.
Ecological and environmental entities, characteristics, properties, relationships and processes.
BIRDS that hunt and kill other animals, especially higher vertebrates, for food. They include the FALCONIFORMES order, or diurnal birds of prey, comprised of EAGLES, falcons, HAWKS, and others, as well as the STRIGIFORMES order, or nocturnal birds of prey, which includes OWLS.
Reproduction without fusion of two types of cells, mostly found in ALGAE; FUNGI; and PLANTS. Asexual reproduction occurs in several ways, such as budding, fission, or splitting from "parent" cells. Only few groups of ANIMALS reproduce asexually or unisexually (PARTHENOGENESIS).
The act of feeding on plants by animals.
The most diversified of all fish orders and the largest vertebrate order. It includes many of the commonly known fish such as porgies, croakers, sunfishes, dolphin fish, mackerels, TUNA, etc.
The family of true toads belonging to the order Anura. The genera include Bufo, Ansonia, Nectophrynoides, and Atelopus.
The effect of GLOBAL WARMING and the resulting increase in world temperatures. The predicted health effects of such long-term climatic change include increased incidence of respiratory, water-borne, and vector-borne diseases.
A family of winged insects of the suborder HETEROPTERA, called assassin bugs, because most prey on other insects. However one subfamily, TRIATOMINAE, attacks humans and other vertebrates and transmits Chagas disease.
An order of heavy-bodied, largely terrestrial BIRDS including pheasants, TURKEYS, grouse, QUAIL, and CHICKENS.
A large order of insects characterized by having the mouth parts adapted to piercing or sucking. It is comprised of four suborders: HETEROPTERA, Auchenorrhyncha, Sternorrhyncha, and Coleorrhyncha.
The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.
Theoretical construct used in applied mathematics to analyze certain situations in which there is an interplay between parties that may have similar, opposed, or mixed interests. In a typical game, decision-making "players," who each have their own goals, try to gain advantage over the other parties by anticipating each other's decisions; the game is finally resolved as a consequence of the players' decisions.
Any of numerous winged hymenopterous insects of social as well as solitary habits and having formidable stings.
A phylum of EUKARYOTES characterized by the presence of cilia at some time during the life cycle. It comprises three classes: KINETOFRAGMINOPHOREA; OLIGOHYMENOPHOREA; and POLYMENOPHOREA.
An inactive stage between the larval and adult stages in the life cycle of insects.
A set of statistical methods used to group variables or observations into strongly inter-related subgroups. In epidemiology, it may be used to analyze a closely grouped series of events or cases of disease or other health-related phenomenon with well-defined distribution patterns in relation to time or place or both.
The discarding or destroying of liquid waste products or their transformation into something useful or innocuous.
An order of MAMMALS, usually flesh eaters with appropriate dentition. Suborders include the terrestrial carnivores Fissipedia, and the aquatic carnivores PINNIPEDIA.
Non-native organisms brought into a region, habitat, or ECOSYSTEM by human activity.
A family of small, gram-negative organisms, often parasitic in humans and other animals, causing diseases that may be transmitted by invertebrate vectors.
The presence of bacteria, viruses, and fungi in the soil. This term is not restricted to pathogenic organisms.
In statistics, a technique for numerically approximating the solution of a mathematical problem by studying the distribution of some random variable, often generated by a computer. The name alludes to the randomness characteristic of the games of chance played at the gambling casinos in Monte Carlo. (From Random House Unabridged Dictionary, 2d ed, 1993)
The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.
Changes in biological features that help an organism cope with its ENVIRONMENT. These changes include physiological (ADAPTATION, PHYSIOLOGICAL), phenotypic and genetic changes.
The change in gene frequency in a population due to migration of gametes or individuals (ANIMAL MIGRATION) across population barriers. In contrast, in GENETIC DRIFT the cause of gene frequency changes are not a result of population or gamete movement.
A species of mosquito in the genus Anopheles and the principle vector of MALARIA in Africa.
Animals considered to be wild or feral or not adapted for domestic use. It does not include wild animals in zoos for which ANIMALS, ZOO is available.
The visually perceived property of objects created by absorption or reflection of specific wavelengths of light.
A genus of bacteria comprised of a heterogenous group of gram-negative small rods and coccoid forms associated with arthropods. (From Bergey's Manual of Systematic Bacteriology, vol 1, 1984)
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
A group of cold-blooded, aquatic vertebrates having gills, fins, a cartilaginous or bony endoskeleton, and elongated bodies covered with scales.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
A climate which is typical of equatorial and tropical regions, i.e., one with continually high temperatures with considerable precipitation, at least during part of the year. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
A mammalian order which consists of 29 families and many genera.
The properties of a pathogen that makes it capable of infecting one or more specific hosts. The pathogen can include PARASITES as well as VIRUSES; BACTERIA; FUNGI; or PLANTS.
A large plant family of the order Asterales, subclass Asteridae, class Magnoliopsida. The family is also known as Compositae. Flower petals are joined near the base and stamens alternate with the corolla lobes. The common name of "daisy" refers to several genera of this family including Aster; CHRYSANTHEMUM; RUDBECKIA; TANACETUM.
Use of naturally-occuring or genetically-engineered organisms to reduce or eliminate populations of pests.
A thick mass of ICE formed over large regions of land; RIVERS; LAKES; ponds; or SEAWATER.
DNA sequences encoding RIBOSOMAL RNA and the segments of DNA separating the individual ribosomal RNA genes, referred to as RIBOSOMAL SPACER DNA.
Behavior in defense of an area against another individual or individuals primarily of the same species.
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
The encapsulated embryos of flowering plants. They are used as is or for animal feed because of the high content of concentrated nutrients like starches, proteins, and fats. Rapeseed, cottonseed, and sunflower seed are also produced for the oils (fats) they yield.
A class of minute animals of the phylum Aschelminthes.
Marine ridges composed of living CORALS, coral skeletons, calcareous algae, and other organisms, mixed with minerals and organic matter. They are found most commonly in tropical waters and support other animal and plant life.
Functions constructed from a statistical model and a set of observed data which give the probability of that data for various values of the unknown model parameters. Those parameter values that maximize the probability are the maximum likelihood estimates of the parameters.
A diverse genus of minute freshwater CRUSTACEA, of the suborder CLADOCERA. They are a major food source for both young and adult freshwater fish.
A genus of planorbid freshwater snails, species of which are intermediate hosts of Schistosoma mansoni.
The unconsolidated mineral or organic matter on the surface of the earth that serves as a natural medium for the growth of land plants.
The rate dynamics in chemical or physical systems.
A widely distributed order of perching BIRDS, including more than half of all bird species.
A rigorously mathematical analysis of energy relationships (heat, work, temperature, and equilibrium). It describes systems whose states are determined by thermal parameters, such as temperature, in addition to mechanical and electromagnetic parameters. (From Hawley's Condensed Chemical Dictionary, 12th ed)
Physiological processes and properties of BACTERIA.
Deoxyribonucleic acid that makes up the genetic material of bacteria.
Insects of the suborder Heterocera of the order LEPIDOPTERA.
Elimination of ENVIRONMENTAL POLLUTANTS; PESTICIDES and other waste using living organisms, usually involving intervention of environmental or sanitation engineers.
PASSERIFORMES of the suborder, Oscines, in which the flexor tendons of the toes are separate, and the lower syrinx has 4 to 9 pairs of tensor muscles inserted at both ends of the tracheal half rings. They include many commonly recognized birds such as CROWS; FINCHES; robins; SPARROWS; and SWALLOWS.
A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
A technique for identifying individuals of a species that is based on the uniqueness of their DNA sequence. Uniqueness is determined by identifying which combination of allelic variations occur in the individual at a statistically relevant number of different loci. In forensic studies, RESTRICTION FRAGMENT LENGTH POLYMORPHISM of multiple, highly polymorphic VNTR LOCI or MICROSATELLITE REPEAT loci are analyzed. The number of loci used for the profile depends on the ALLELE FREQUENCY in the population.
Animate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential sources of disease outbreaks. Reservoirs are distinguished from vectors (DISEASE VECTORS) and carriers, which are agents of disease transmission rather than continuing sources of potential disease outbreaks.
The continuous remodeling of MITOCHONDRIA shape by fission and fusion in response to physiological conditions.
One of the three domains of life (the others being BACTERIA and ARCHAEA), also called Eukarya. These are organisms whose cells are enclosed in membranes and possess a nucleus. They comprise almost all multicellular and many unicellular organisms, and are traditionally divided into groups (sometimes called kingdoms) including ANIMALS; PLANTS; FUNGI; and various algae and other taxa that were previously part of the old kingdom Protista.
A plant species of the family BRASSICACEAE best known for the edible roots.
Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.
The reduction or regulation of the population of mosquitoes through chemical, biological, or other means.
An acute febrile disease transmitted by the bite of AEDES mosquitoes infected with DENGUE VIRUS. It is self-limiting and characterized by fever, myalgia, headache, and rash. SEVERE DENGUE is a more virulent form of dengue.
Large natural streams of FRESH WATER formed by converging tributaries and which empty into a body of water (lake or ocean).
Double-stranded DNA of MITOCHONDRIA. In eukaryotes, the mitochondrial GENOME is circular and codes for ribosomal RNAs, transfer RNAs, and about 10 proteins.
The salinated water of OCEANS AND SEAS that provides habitat for marine organisms.
Diseases of plants.
A natural association between organisms that is detrimental to at least one of them. This often refers to the production of chemicals by one microorganism that is harmful to another.
Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.
A large family of narrow-leaved herbaceous grasses of the order Cyperales, subclass Commelinidae, class Liliopsida (monocotyledons). Food grains (EDIBLE GRAIN) come from members of this family. RHINITIS, ALLERGIC, SEASONAL can be induced by POLLEN of many of the grasses.
Measurements of the height, weight, length, area, etc., of the human and animal body or its parts.
The class Insecta, in the phylum ARTHROPODA, whose members are characterized by division into three parts: head, thorax, and abdomen. They are the dominant group of animals on earth; several hundred thousand different kinds having been described. Three orders, HEMIPTERA; DIPTERA; and SIPHONAPTERA; are of medical interest in that they cause disease in humans and animals. (From Borror et al., An Introduction to the Study of Insects, 4th ed, p1)
The interactions between a host and a pathogen, usually resulting in disease.
Theoretical representations that simulate the behavior or activity of the neurological system, processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.
The monitoring of the level of toxins, chemical pollutants, microbial contaminants, or other harmful substances in the environment (soil, air, and water), workplace, or in the bodies of people and animals present in that environment.
The chromosomal constitution of a cell containing multiples of the normal number of CHROMOSOMES; includes triploidy (symbol: 3N), tetraploidy (symbol: 4N), etc.
The science, art or practice of cultivating soil, producing crops, and raising livestock.

Prediction of genetic contributions and generation intervals in populations with overlapping generations under selection. (1/4953)

A method to predict long-term genetic contributions of ancestors to future generations is studied in detail for a population with overlapping generations under mass or sib index selection. An existing method provides insight into the mechanisms determining the flow of genes through selected populations, and takes account of selection by modeling the long-term genetic contribution as a linear regression on breeding value. Total genetic contributions of age classes are modeled using a modified gene flow approach and long-term predictions are obtained assuming equilibrium genetic parameters. Generation interval was defined as the time in which genetic contributions sum to unity, which is equal to the turnover time of genes. Accurate predictions of long-term genetic contributions of individual animals, as well as total contributions of age classes were obtained. Due to selection, offspring of young parents had an above-average breeding value. Long-term genetic contributions of youngest age classes were therefore higher than expected from the age class distribution of parents, and generation interval was shorter than the average age of parents at birth of their offspring. Due to an increased selective advantage of offspring of young parents, generation interval decreased with increasing heritability and selection intensity. The method was compared to conventional gene flow and showed more accurate predictions of long-term genetic contributions.  (+info)

Ancestral Asian source(s) of new world Y-chromosome founder haplotypes. (2/4953)

Haplotypes constructed from Y-chromosome markers were used to trace the origins of Native Americans. Our sample consisted of 2,198 males from 60 global populations, including 19 Native American and 15 indigenous North Asian groups. A set of 12 biallelic polymorphisms gave rise to 14 unique Y-chromosome haplotypes that were unevenly distributed among the populations. Combining multiallelic variation at two Y-linked microsatellites (DYS19 and DXYS156Y) with the unique haplotypes results in a total of 95 combination haplotypes. Contra previous findings based on Y- chromosome data, our new results suggest the possibility of more than one Native American paternal founder haplotype. We postulate that, of the nine unique haplotypes found in Native Americans, haplotypes 1C and 1F are the best candidates for major New World founder haplotypes, whereas haplotypes 1B, 1I, and 1U may either be founder haplotypes and/or have arrived in the New World via recent admixture. Two of the other four haplotypes (YAP+ haplotypes 4 and 5) are probably present because of post-Columbian admixture, whereas haplotype 1G may have originated in the New World, and the Old World source of the final New World haplotype (1D) remains unresolved. The contrasting distribution patterns of the two major candidate founder haplotypes in Asia and the New World, as well as the results of a nested cladistic analysis, suggest the possibility of more than one paternal migration from the general region of Lake Baikal to the Americas.  (+info)

Long-term studies of hantavirus reservoir populations in the southwestern United States: rationale, potential, and methods. (3/4953)

Hantaviruses are rodent-borne zoonotic agents that cause hemorrhagic fever with renal syndrome in Asia and Europe and hantavirus pulmonary syndrome (HPS) in North and South America. The epidemiology of human diseases caused by these viruses is tied to the ecology of the rodent hosts, and effective control and prevention relies on a through understanding of host ecology. After the 1993 HPS outbreak in the southwestern United States, the Centers for Disease Control and Prevention initiated long-term studies of the temporal dynamics of hantavirus infection in host populations. These studies, which used mark-recapture techniques on 24 trapping webs at nine sites in the southwestern United States, were designed to monitor changes in reservoir population densities and in the prevalence and incidence of infection; quantify environmental factors associated with these changes; and when linked to surveillance databases for HPS, lead to predictive models of human risk to be used in the design and implementation of control and prevention measures for human hantavirus disease.  (+info)

Long-term hantavirus persistence in rodent populations in central Arizona. (4/4953)

For 35 months, we monitored hantavirus activity in rodent populations in central Arizona. The most frequently captured hantavirus antibody-positive rodents were Peromyscus boylii and P. truei. Antibody-positive P. boylii were more frequently male (84%), older, and heavier, and they survived longer on trapping web sites than antibody-negative mice. The number of antibody-positive P. boylii was greater during high population densities than during low densities, while antibody prevalence was greater during low population densities. Virus transmission and incidence rates, also related to population densities, varied by trapping site. The spatial distribution of antibody-positive P. boylii varied by population density and reflected the species preference for dense chaparral habitats. The focal ranges of antibody-positive P. boylii also demonstrated a patchy distribution of hantavirus.  (+info)

A longitudinal study of Sin Nombre virus prevalence in rodents, southeastern Arizona. (5/4953)

We determined the prevalence of Sin Nombre virus antibodies in small mammals in southeastern Arizona. Of 1,234 rodents (from 13 species) captured each month from May through December 1995, only mice in the genus Peromyscus were seropositive. Antibody prevalence was 14.3% in 21 white-footed mice (P. leucopus), 13.3% in 98 brush mice (P. boylii), 0.8% in 118 cactus mice (P. eremicus), and 0% in 2 deer mice (P. maniculatus). Most antibody-positive mice were adult male Peromyscus captured close to one another early in the study. Population dynamics of brush mice suggest a correlation between population size and hantavirus-antibody prevalence.  (+info)

The changing elderly population and future health care needs. (6/4953)

The impending growth of the elderly population requires both fiscal and substantive changes in Medicare and Medicaid that are responsive to cost issues and to changing patterns of need. More emphasis is required on chronic disease management, on meaningful integration between acute and long-term care services, and on improved coordination between Medicare and Medicaid initiatives. This paper reviews various trends, including the growth in managed-care approaches, experience with social health maintenance organizations and Program of All-Inclusive Care for the Elderly demonstrations, and the need for a coherent long-term care policy. Such policies, however, transcend health care and require a broad range of community initiatives.  (+info)

Sex-biased dispersal in sperm whales: contrasting mitochondrial and nuclear genetic structure of global populations. (7/4953)

The social organization of most mammals is characterized by female philopatry and male dispersal. Such sex-biased dispersal can cause the genetic structure of populations to differ between the maternally inherited mitochondrial DNA (mtDNA) and the bi-parental nuclear genome. Here we report on the global genetic structure of oceanic populations of the sperm whale, one of the most widely distributed mammalian species. Groups of females and juveniles are mainly found at low latitudes, while males reach polar waters, returning to tropical and subtropical waters to breed. In comparisons between oceans, we did not find significant heterogeneity in allele frequencies of microsatellite loci (exact test; p = 0.23). Estimates of GST = 0.001 and RST = 0.005 also indicated negligible if any nuclear DNA differentiation. We have previously reported significant differentiation between oceans in mtDNA sequences. These contrasting patterns suggest that interoceanic movements have been more prevalent among males than among females, consistent with observations of females being the philopatric sex and having a more limited latitudinal distribution than males. Consequently, the typical mammalian dispersal pattern may have operated on a global scale in sperm whales.  (+info)

Patient health management: a promising paradigm in Canadian healthcare. (8/4953)

Disease management, or the focused application of resources to achieve desired health outcomes, began in Canada in 1971 with the introduction of a universal healthcare program and a single government payor. Although relatively unfocused and nonrestrictive by contemporary standards, this program was successful in terms of outcomes. However, it is expensive, and Canada's rapidly aging population is fueling a growing demand for more efficacious medical therapies. As a result, isolated services are being restricted in an effort to reduce costs. As a result of these changes and low prescription and patient compliance rates for efficacious therapies, total system costs have risen, there is a growing concern about deterioration of health outcomes, and stakeholders are dissatisfied. To optimize healthcare outcomes and reduce costs, a new paradigm--patient health management (PHM)--has emerged. With PHM, clinical and cost outcomes are continually measured and communicated to providers in an attempt to promote more efficacious care. PHM also seeks to avoid restrictive practices that are now associated with detrimental health outcomes and increased costs. PHM has proved successful when applied to acute and chronic cardiac disease treatment. It remains untested for most other diseases, but available data suggest that the comprehensive, evidence-based disease and systems management that characterizes PHM is likely to achieve the best health outcomes for the most people at the lowest possible costs.  (+info)

Objective: To assess evidence for residential mobility in childhood having an adverse association with health outcomes through the life course.. Methods: A systematic search of medical and social sciences literature was undertaken to identify research defining residential mobility as an independent variable and in which health outcomes were described and objectively measured. Studies were excluded that investigated international migration for asylum or were limited to educational outcomes. Two reviewers assessed each study using quality criteria with particular attention to the consideration of confounders and potential for bias. Data were extracted for analysis using a structured form.. Results: Twenty-two studies were included for this review. Outcomes identified in association with residential mobility included: higher levels of behavioural and emotional problems; increased teenage pregnancy rates; accelerated initiation of illicit drug use; adolescent depression; reduced continuity of ...
Results Consistent with previous research we find a positive association between cumulative residential mobility and cannabis use with conventional logistic regression models (Odds Ratio: 2.56, 95% Confidence Interval: 1.20-5.78), implying that adolescents who experience a residential change are more likely to use cannabis than those who remain residentially stable. However, decomposing this relationship into its between- and within-child components reveals that a conventional model is underspecified and misleading; we find that differences in cannabis use between mobile and non-mobile adolescents are due to underlying selection differences between these groups (between-child log odds: 3.56, standard error: 1.22), not by a change in status of residential mobility (within-child log odds: 1.33, standard error: 1.02). ...
Residential mobility among foreign-born persons living in Sweden is associated with lower mortality Björn Albin1,2, Katarina Hjelm1,2, Jan Ekberg3, Sölve Elmståhl41School of Health and Caring Sciences, Linnaeus University, Växjö, Sweden; 2Department of Health Sciences, Division of Geriatric Medicine, Lund University, Sweden; 3Centre of Labour Market Policy Research (CAFO), School of Management and Economics, Växjö University, Sweden; 4Department of Health Sciences, Division of Geriatric Medicine, Lund University, SwedenAbstract: There have been few longitudinal studies on the effect of within-country mobility on patterns of mortality in deceased foreign-born individuals. The results have varied; some studies have found that individuals who move around within the same country have better health status than those who do not change their place of residence. Other studies have shown that changing one’s place of residence leads to more self-reported health problems
Work looking at the interplay between residential mobility, deprivation, age, personal socioeconomic circumstance, and health outcomes.
This study investigates the magnitude and persistence of elevated post-separation residential mobility (i.e. residential instability) in five countries (Au
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Vision in these deer is determined by alleles in a single gene, with Q being the dominant allele. In this post, we share questions based on the new syllabus. Chapter 1: Population dynamics QUESTION 1: Cambridge IGCSE Geography 0460/11 Q1 June 2009 (a)Study Fig. . Such eco-evolutionary dynamics are likely to occur in modern humans and may influence population dynamics. GCSE Population dynamics. For the exam, you will get 55 of these type of questions. [6] World Population Prospects: The 2017 Revision; 1.09% is â ¦ We have a question bank with different types of MCQs for all Class 8 subjects, including Science, Mathematics, Hindi, English and Social Studies. REVIEW QUESTIONS FOR SECOND EXAM BIOLOGY 4253 ECOLOGY Chapter 11 (Population dynamics) Terms: demographic transition, demographic stochasticity, delayed density dependence, Allee affect, environmental stochasticity, source and sink populations, rescue effect 1. . Leaving Cert and Junior Cert exam paper questions and marking schemes listed by ...
Conference Proceeding: Bracciali A, Caravagna G & Ullah A (2013) Survival vs. Revenue: Modelling and Reasoning on Population Dynamics. In: Wainer G, Mosterman P, Barros F & Zacharewicz G (eds.) DEVS 13 Proceedings of the Symposium on Theory of Modeling & Simulation - DEVS Integrative M&S Symposium. Symposium on Theory of Modeling and Simulation (TMS 2013), San Diego, CA, USA, 07.04.2013-10.04.2013. San Diego, CA, USA: Society for Computer Simulation International. http://www.tms-devs.org/
article{9837a013-2002-40ce-93f0-0bf266da9173, abstract = {Within the paradigm of population dynamics a central task is to identify environmental factors affecting population change and to estimate the strength of these effects. We here investigate the impact of observation errors in measurements of population densities on estimates of environmental effects. Adding observation errors may change the autocorrelation of a population time series with potential consequences for estimates of effects of autocorrelated environmental covariates. Using Monte Carlo simulations, we compare the performance of maximum likelihood estimates from three stochastic versions of the Gompertz model (log-linear first order autoregressive model), assuming 1) process error only, 2) observation error only, and 3) both process and observation error (the linear state-space model on log-scale). We also simulated population dynamics using the Ricker model, and evaluated the corresponding maximum likelihood estimates for ...
The term stable population refers to a population with an unchanging (but possibly nonzero) rate of growth and an unchanging age composition (i.e., the population pyramid does not change in shape) as a result of age-specific birth rates and age-specific death rates that have remained constant for a sufficiently long time. A stable population may or may not have zero population growth. We can have stable populations that are growing, and we can also have stable populations that are declining. ...
Sandeel (mainly Ammodytes marinus) is a very important forage fish in the North Sea, because it constitutes the major food source for many predator fish, seabirds and marine mammals. Furthermore, the sandeel fishery is one of the largest single species fisheries in the North Sea. The abundance of sandeel varies from year to year, and thus, ecosystems can be highly sensitive to changes in the population dynamics of sandeel. While the impact on the ecosystem is well documented, the underlying processes and mechanisms behind the population dynamics of sandeel are still vaguely understood.. In his PhD thesis Ole Henriksen, DTU Aqua, unravels some of the most important factors driving the abundances of sandeel. The assemblage of knowledge gathered-on growth, density dependence, habitat, food availability, predation, fisheries, temperature, oceanography and broad-scale climate-provides a baseline and annotated bibliography for scientists. Furthermore, findings from four studies are highlighted, where ...
Demographic transition from primitive population stability to modern population stability is happening in developed countries There is need to ensure that this transition happens in developing countries also Primitive population stability of high birth rates were offset by high infant and childhood mortality has transitioned to a modern population stability of low infant and childhood mortality are balanced by low birth rates Epidemiologic transition: During primitive population stability CDR was high (,40) - receding fatal diseases, epidemics and famines reduced CDR to ~11 - now most people in developed countries die from cancer, cardiovascular diseases and other degenerative diseases Fertility transition: CBR in the developed countries declined from a high of 40-50 during primitive population stability to 8-12 of the modern population stability due to industrialization, economic development and social modernization Economic development and social modernization has been observed to bring about ...
The way that mothers provision their offspring can have important consequences for their offsprings performance throughout life. Models suggest that maternally induced variation in life histories may have large population dynamical effects, even perhaps driving cycles such as those seen in forest Lepidoptera. The evidence for large maternal influences on population dynamics is unconvincing, principally because of the difficulty of conducting experiments at both the individual and population level. In the soil mite, Sancassania berlesei, we show that there is a trade-off between a females fecundity and the per-egg provisioning of protein. The mothers position on this trade-off depends on her current food availability and her age. Populations initiated with 250 eggs of different mean sizes showed significant differences in the population dynamics, converging only after three generations. Differences in the growth, maturation and fecundity of the initial cohort caused differences in the ...
Many animal populations providing ecosystem services, including harvest, live in seasonal environments and migrate between seasonally distinct ranges. Unfortunately, two major sources of human-induced global change threaten these populations: climate change and anthropogenic barriers. Anthropogenic infrastructure developments present a global threat to animal migrations through increased migration mortality or behavioral avoidance. Climate change alters the seasonal and spatial dynamics of resources and therefore the effects of migration on population performance. We formulated a population model with ideal-free migration to investigate changes in population size and harvest yield due to barriers and seasonal dynamics. The model predicted an increasing proportion of migrants when the difference between areas in seasonality or carrying capacity increased. Both migration cost and behavioral avoidance of barriers substantially reduced population size and harvest yields. Not surprisingly, the ...
Many animal populations providing ecosystem services, including harvest, live in seasonal environments and migrate between seasonally distinct ranges. Unfortunately, two major sources of human-induced global change threaten these populations: climate change and anthropogenic barriers. Anthropogenic infrastructure developments present a global threat to animal migrations through increased migration mortality or behavioral avoidance. Climate change alters the seasonal and spatial dynamics of resources and therefore the effects of migration on population performance. We formulated a population model with ideal-free migration to investigate changes in population size and harvest yield due to barriers and seasonal dynamics. The model predicted an increasing proportion of migrants when the difference between areas in seasonality or carrying capacity increased. Both migration cost and behavioral avoidance of barriers substantially reduced population size and harvest yields. Not surprisingly, the ...
TY - JOUR. T1 - Apparent breeding success drives long-term population dynamics of a migratory swan. AU - Nuijten, Rascha. AU - Vriend, S.J.G.. AU - Wood, Kevin A.. AU - Haitjema, Trinus. AU - Rees, Eileen C.. AU - Jongejans, Eelke. AU - Nolet, B.A.. N1 - 7028, AnE; Data archiving: data archived in Dryad. PY - 2020. Y1 - 2020. N2 - The ability of a species to adapt to environmental change is ultimately reflected in its vital rates - i.e., survival and reproductive success of individuals. Together, vital rates determine trends in numbers, commonly monitored using counts of species abundance. Rapid changes in abundance can give rise to concern, leading to calls for research into the biological mechanisms underlying variations in demography. For the NW European population of Bewicks swan (Cygnus columbianus bewickii), there have been major changes in the population trends recorded during nearly five decades of monitoring (1970‐2016). The total number of birds increased to a maximum of c. 30,000 ...
This 2015 OECD Economic Survey of Belgium examines recent economic developments, policies and prospects. Special chapters cover integration of immigrants and the housing sector.. ...
By David Baker and William Smith[1] Widespread formal education is shaping population dynamics globally. From new trends in mortality and health disparities in the United States to demographic and epidemiological population transitions in less developed nations, access to schooling is proving to be one of demographys most potent causal factors. Research has repeatedly found education…
There is growing evidence that climate change causes an increase in variation in conditions for plant and animal populations. This increase in variation, e.g. amplified inter-annual variability in temperature and rainfall has population dynamical consequences because it raises the variation in vital demographic rates (survival, reproduction) in these populations. In turn, this amplified environmental variability enlarges population extinction risk. This paper demonstrates that currently used nature conservation policies, principles, and generic and specific design criteria have to be adapted to these new insights. A simulation shows that an increase in variation in vital demographic rates can be compensated for by increasing patch size. A small, short-lived bird species like a warbler that is highly sensitive to environmental fluctuations needs more area for compensation than a large, long-lived bird species like a Bittern. We explore the conservation problems that would arise if patches or ...
In this paper, we consider a reaction-diffusion model in population dynamics and study the impact of different types of Allee effects with logistic growth in the heterogeneous closed region. For strong Allee effects, usually, species unconditionally die out and an extinction-survival situation occurs when the effect is weak according to the resource and sparse functions. In particular, we study the impact of the multiplicative Allee effect in classical diffusion when the sparsity is either Show moreIn this paper, we consider a reaction-diffusion model in population dynamics and study the impact of different types of Allee effects with logistic growth in the heterogeneous closed region. For strong Allee effects, usually, species unconditionally die out and an extinction-survival situation occurs when the effect is weak according to the resource and sparse functions. In particular, we study the impact of the multiplicative Allee effect in classical diffusion when the sparsity is either positive or ...
Principles of Population Dynamics and Their Application PDF/EPUB ↠ of Population Dynamics MOBI ó Population Dynamics and Their eBook ð of Population Dynamics and Their ePUB ☆ Population Dynamics PDF Ê Principles of eBook ð This book provides an introduction to population dynamics exploring rules that govern change in any dynamic system and applying these gen.
PubMed Central Canada (PMC Canada) provides free access to a stable and permanent online digital archive of full-text, peer-reviewed health and life sciences research publications. It builds on PubMed Central (PMC), the U.S. National Institutes of Health (NIH) free digital archive of biomedical and life sciences journal literature and is a member of the broader PMC International (PMCI) network of e-repositories.
We develop a biologically correct cost system for production systems facing invasive pests that allows the estimation of population dynamics without a priori knowledge of their true values. We apply that model to a data set for olive producers in Crete and derive from it predictions about the underlying populations dynamics. Those dynamics are compared to information on population dynamics obtained from pest sampling with extremely favorable results., Separable technologies, Pest population, Damage control, Olive farms, Greece, C31,Q21,Q22, Environmental Economics , Theory
TY - JOUR. T1 - Life-History variation predicts the effects of demographic stochasticity on avian population Dynamics. AU - Sæther, B-E.. AU - Engen, S.. AU - Møller, A.P.. AU - Weimerskirch, H.. AU - Visser, M.E.. AU - Fiedler, W.. AU - Matthysen, E.. AU - Lambrechts, M.M.. AU - Badyaev, A.. AU - Becker, P.H.. AU - Brommer, J.E.. AU - Bukacinski, D.. AU - Bukacinski, M.. AU - Christensen, H.. AU - Dickinson, J.. AU - du Feu, C.. AU - Gehlbach, F.R.. AU - Heg, D.. AU - Hötker, H.. AU - Merilä, J.. AU - Nielsen, J.T.. AU - Rendell, W.. AU - Robertson, R.J.. AU - Thomson, D.L.. AU - Török, J.. AU - van Hecke, P.. N1 - Reporting year: 2004 Metis note: 3354; CTE; PVD ; AnE; file:///L:/Endnotedatabases/NIOOPUB/pdfs/Pdfs2004/Saether_ea_3354.pdf. PY - 2004. Y1 - 2004. N2 - Comparative analyses of avian population fluctuations have shown large interspecific differences in population variability that have been difficult to relate to variation in general ecological characteristics. Here we show that ...
Population dynamics of a predator-prey system is usually simulated by the classical Lotka-Volterra models, which were successfully applied to the population dynamics of snowshoe hare and lynx and many other predator-prey systems. Attempts were made to apply them also to insect predator-prey systems, but in terms of biological control, they did not reveal the features of the predators that control the abundance of their prey. The most conspicuous example of failure of Lotka-Volterra models applied to insect predator-prey systems are ladybird-aphid systems, in which these models usually fail to fit empirical data. Because of their practical importance and because they are very well studied, we have chosen aphid-ladybird systems as a model. We summarize the results published on various aspects of the population dynamics of aphid-ladybird systems and present them in the context of empirical data. Using new data, we more closely specify the existing metapopulation model of aphid-ladybird ...
Kobayashi, Tsuyoshi, Ryder, Darren S., Ralph, Timothy J., Mazumder, Debashish, Saintilan, Neil, Iles, Jordan, Knowles, Lisa, Thomas, Rachael and Hunter, Simon. (2011) Longitudinal spatial variation in ecological conditions in an in-channel floodplain river system during flow pulses. River Research and Applications. 27, pp. 461 - 472. https://doi.org/10.1002/rra.1381 ...
ABSTRACT: In marine systems, empirical studies demonstrating effects of macroparasites on host population dynamics are relatively few. We tested the effects of a copepod macroparasite infecting the gills of a small coral reef fish, the bridled goby Coryphopterus glaucofraenum. Fish that were naturally infected and uninfected were tagged as individuals and tracked in the field for 5 mo. Parasitism was associated with an increase in gill ventilation rate, and a reduction in feeding. More importantly, parasitized fish showed significantly reduced growth (by 66%) and gonad mass (by 68%) compared to uninfected fish, and parasitism increased instantaneous mortality by a factor of 1.8. Since the prevalence of infection was higher in areas of high goby density, parasite-induced mortality is a possible cause of host density dependence. These results imply a major effect of parasitism on host population dynamics and suggest that parasitism warrants closer attention by marine ecologists. ...
FALL 2016 SEPTEMBER 2016 Jie Ma, Department of Economics, McGill University How High-Skilled Immigrants Affect Natives Occupational Choices. ...
A no-frills group of wildlife enthusiasts, scientists, photographers and local residents wishing to see wild boar and all other wildlife thrive in the Forest of Dean and elsewhere in the UK. Founded by David J Slater and Joyce Moss in the summer of 2011 as an independent conservation group with no prior affiliations. Hoping to promote understanding of wild boar and as a pressure group to produce a realistic and science-based management plan of wild boar in the UK. E-mail us via my complete profile below. Media enquirers only - please telephone 07999950697 ...
Like predation and competition, mutualism is now recognized as a consumer resource (C-R) interaction, including, in particular, bi-directional (e.g., coral, plant- mycorrhizae) and uni-directional (e.g., ant-plant defense, plant-pollinator) C-R mutualisms. Here, we develop general theory for the density-dependent population dynamics of mutualism based on the C-R mechanism of interspecific interaction. To test the influence of C-R interactions on the dynamics and stability of bi- and uni-directional C-R mutualisms, we developed simple models that link consumer functional response of one mutualistic species with the resources supplied by another. Phase-plane analyses show that the ecological dynamics of C-R mutualisms are stable in general. Most transient behavior leads to an equilibrium of mutualistic coexistence, at which both species densities are greater than in the absence of interactions. However, due to the basic nature of C-R interactions, certain density-dependent conditions can lead to C-R
1. Metapopulation microcosms were constructed to test the effect of four different types of habitat heterogeneity on the dynamics and dispersal in spatially extended systems; homogeneity, spatial heterogeneity, temporal heterogeneity and spatio-temporal heterogeneity. Resources were distributed across discrete habitat patches in bruchid beetle (Callosobruchus maculatus) metapopulations, and long-term time series were recorded. 2. Mathematical models were fitted to the long-term time series from the experimental systems using a maximum likelihood approach. Models were composed of separate birth, death, emigration and immigration terms all of which incorporated stochasticity drawn from different probability distributions. Models with density-dependent and density-independent birth, death and emigration terms were investigated and, in each case, the model that best described the empirical data was identified. 3. At the local scale, population sizes differed between patches depending on the type of
Population dynamics result from the interplay of density-independent and density-dependent processes. Understanding this interplay is important, especially for being able to predict near-term population trajectories for management. In recent years, the study of model systems-experimental, observational and theoretical-has shed considerable light on the way that the both density-dependent and -independent aspects of the environment affect population dynamics via impacting on the organisms life history and therefore demography. These model-based approaches suggest that (i) individuals in different states differ in their demographic performance, (ii) these differences generate structure that can fluctuate independently of current total population size and so can influence the dynamics in important ways, (iii) individuals are strongly affected by both current and past environments, even when the past environments may be in previous generations and (iv) dynamics are typically complex and transient due to
Habitat, Human Influences, Density-dependent Factors and Competition. Habitat, encompassing areal extent, topography, vegetation, forage quantity, forage quality and forage availability, is a key influence on the population ecology of all species. Total available habitat can be an important and obvious influence on population dynamics where density of humans is high. Topography affects vegetation as well as precipitation, wind, temperature and phenology, and thus plays an important role in caribou ecology. Vegetation is crucial because caribou must travel through, exist in and also consume it to survive. Caribou generally avoid dense brush because it is difficult to travel through, to detect predators in, and are low in forage quantity and quality in winter. Deciduous forests are avoided in winter for similar reasons. Forage quantity is critical for obvious reasons; if any animal cannot obtain sufficient forage they will fail to reproduce and/or die. While more subtle, forage quality is ...
My initial graduate work was on spatial population dynamics and specifically how spatial interaction fundamentally changes population dynamics and to what extent does it not fundamentally change populations dynamics. If it does fundamentally change dynamics, then how simple can that spatial model be? At what point can a uniform mixing model approximate the properties of a non-uniform mixing process? The papers Is diffusion too simple?, Basic epidemiological concepts in a spatial context, and Running from trouble were all exploring these ideas. I reviewed some of these ideas in Partial differential equation models in ecology. Later I taught a graduate course on spatial dynamics which tried to bring all these ideas together. My post-graduate work was focused on an experimental study of metapopulation dynamics using mosquitoes. This was a huge perturbation experiment to test some ideas about how metapopulation dynamics should change in response to variability in the environment. Since 1999, ...
The apparent failure of ecosystems to recover from increasingly widespread disturbance is a global concern. Despite growing focus on factors inhibiting resilience and restoration, we still know very little about how demographic and population processes influence recovery. Using inverse and forward demographic modelling of 531 post‐fire sagebrush populations across the western US, we show that demographic processes during recovery from seeds do not initially lead to population growth but rather to years of population decline, low density, and risk of extirpation after disturbance and restoration, even at sites with potential to support long‐term, stable populations. Changes in population structure, and resulting transient population dynamics, lead to a | 50% decline in population growth rate after disturbance and significant reductions in population density. Our results indicate that demographic processes influence the recovery of ecosystems from disturbance and that demographic analyses can be used
Northeastern Forest Experiment Station 1969. Forest insect population dynamics. Proceedings Forest Insect Population Dynamics Workshop. (4 of 4). Res. Pap. NE-125. Upper Darby, PA: U. S. Department of Agriculture, Forest Service Northeastern Forest Experiment Station. 104-128 p. ...
This Population Dynamics Lesson Plan is suitable for 3rd - 5th Grade. Students watch a video on population dynamics. They conduct an experiment where they fill up a designated space with students.
TY - GEN. T1 - Population dynamics, life-history traidoffs and phenotypic fitness. AU - Kaitala, V.. PY - 1994. Y1 - 1994. KW - Fitness. KW - Genetic algorithms. KW - Life-history. KW - Population dynamics. KW - Fitness. KW - Genetic algorithms. KW - Life-history. KW - Population dynamics. KW - Fitness. KW - Genetic algorithms. KW - Life-history. KW - Population dynamics. M3 - Conference contribution. SP - 185. EP - 199. BT - Proc. of the Second Finnish Workshop on Genetic Algorithms and their Applications, Vaasa, Finland, March 17-18, 1994. ER - ...
This chapter evaluates various methods for inferring how phenotypes/genotypes influence population dynamics, including extensions of the year-by-year tracking approach used in analyzing the eco-to-evo side of eco-evolutionary dynamics. It provides a detailed outline of the various possibilities, including complexities that move beyond population dynamics. The chapter examines how maladaptation resulting from environmental change might decrease individual fitness and contribute to population declines, range contractions, and extirpations. It considers the extent to which contemporary evolution helps to recover individual fitness and population size, which might then make the difference between persistence versus extirpation and range expansion versus contraction. A final analysis asks how phenotypic variation within populations and species influences population dynamics.
Population dynamics is an important concept in ecology and refers to the ways in which a populations composition changes over time, both in the short-term and the long-term. Understanding the composition of a population is imperative to understanding growth trends and thus, a populations demography.. Population dynamics is not a novel term in ecology. In fact, studying population size goes far back in scientific research. Early research can be dated back to the 1600s. It was in 1662 that John Graunt was fascinated by mortality rates in Britain and made a treatise for the population of Britain to analyse what influenced the age of death.. Furthermore, population dynamics is a rather mathematical branch of ecology because it uses equations to model how a population may evolve over time. There is a simple equation which can be used to model how populations change over time. This equation considers BIDE dynamics:. Nt+1 = Nt + B + I - D - E. Variables:. Nt+1 = population size at some future ...
We conclude that the increasing spatial synchrony of metapopulation dynamics in 1993-2013 (figure 1c,d), reflected in the increasing amplitude of metapopulation fluctuations (figure 1a), is caused by increasing frequency of dry weather in July (figure 3b,c), which leads to withering of host plants and subsequent larval mortality. We discuss the effect of drought via host plant quality below, but observe meanwhile that, following a steep decline, the metapopulation is largely released from density-dependent regulatory processes (figure 3a), which has allowed rapid recovery and hence no long-term declining trend in the size of the metapopulation (figure 1a). The maximal fecundity of the Glanville fritillary is very high, as females may lay more than 1000 eggs [42], which allows, when conditions are favourable, rapid population increase. The related and biologically similar species Euphydryas aurinia used to exhibit outbreak population dynamics in the UK in the early part of the twentieth century ...
health and population dynamics would seem to represent different fields of study. Thus, when mention is made of health planning, the main preoccupation from the health point of view seem to be the provision of health infrastructure. In point of fact,health planning embraces population dynamics because the current structure and, feasible development of population in the future determine the health infrastructure required now and in future. It may be just as well to note that the argument is about public health, a term which embraces far more than health serious and staff. Population dynamics, the three majority of components of which are mortality, fertility and growth, offer a field of investigation in common with health. This is particularly so because health and population dynamics fall within the framework of development planning, and influence the various strategies adopted in national development plans ...
Looking for population dynamics? Find out information about population dynamics. The aggregate of processes that determine the size and composition of any population Explanation of population dynamics
Looking for Population Dynamics, Animal? Find out information about Population Dynamics, Animal. the regular patterns of change in the number of individuals in the population of a given species during the course of a year or a number of years ,... Explanation of Population Dynamics, Animal
Abstract: Abstract Background Methods for analyzing space-time variation in risk in case-control studies typically ignore residential mobility. We develop an approach for analyzing case-control data for mobile individuals and apply it to study bladder cancer in 11 counties in southeastern Michigan. At this time data collection is incomplete and no inferences should be drawn - we analyze these data to demonstrate the novel methods. Global, local and focused clustering of residential histories for 219 cases and 437 controls is quantified using time-dependent nearest neighbor relationships. Business address histories for 268 industries that release known or suspected bladder cancer carcinogens are analyzed. A logistic model accounting for smoking, gender, age, race and education specifies the probability of being a case, and is incorporated into the cluster randomization procedures. Sensitivity of clustering to definition of the proximity metric is assessed for 1 to 75 k nearest neighbors. Results ...
This chapter examines the dynamics of basic population models, with a particular focus on the general biological conditions under which population dynamics are stabilized, or destabilized, by increased population growth rates. Three classes of population models are discussed in relation to excitable and nonexcitable interactions: continuous logistic growth models, discrete equations, and continuous models with stage-structured lags. The chapter shows how increasing per capita growth rates tend to stabilize population models as a result of excitable interactions; that is, when dynamic trajectories monotonically approach an equilibrium after a localized perturbation. However, lags in population models tend to give rise to dynamics with oscillatory decays to equilibrium or sustained oscillations around the carrying capacity. Such oscillatory decays or sustained oscillations are only further destabilized by increased growth or production rates. The chapter concludes with a review of empirical evidence for
This book is an introduction to mathematical biology for students with no experience in biology, but who have some mathematical background. The work is focused on population dynamics and ecology, following a tradition that goes back to Lotka and Volterra, and includes a part devoted to the spread
Extreme climatic conditions and their ecological impacts are currently emerging as critical features of climate change. We studied extreme sea ice condition (ESIC) and found it impacts both life-history traits and population dynamics of an Antarctic seabird well beyond ordinary variability. The Southern Fulmar (Fulmarus glacialoides) is an ice-dependent seabird, and individuals forage near the ice edge. During an extreme unfavorable year (when sea ice area is reduced and distance between ice edge and colony is high), observed foraging trips were greater in distance and duration. As a result, adults brought less food to their chicks, which fledged in the poorest body condition. During such unfavorable years, breeding success was extremely low and population growth rate (λ) was greatly reduced. The opposite pattern occurred during extreme favorable years. Previous breeding status had a strong influence on life-history traits and population dynamics, and their responses to extreme conditions. ...
The post-doc position is part of the NWO-VICI project Adapting to a warmer world: phenology, physiology and fitness. In this project, we study selection on phenotypic plasticity in timing of reproduction in great tits in relation to global climate change. There are five integrated subprojects ranging from quantitative genetics, population dynamics and reproductive physiology to genomics. Four of these subprojects are underway and we are now looking for a post-doctoral candidate for the fifth subproject on population dynamics. This project will be carried out in collaboration with Prof Bernt-Erik Saether (NTNU, Trondheim, Norway) and Dr Stephanie Jenouvrier (CNRS, France & WHOI, USA ...
Further information: Population dynamics and Lotka-Volterra equations. In the absence of predators, the population of a species ... Such models predict widely differing and often chaotic predator-prey population dynamics.[157][159] The presence of refuge ... may enable prey to maintain larger populations but may also destabilize the dynamics.[160][161][162][163] ... or changes in its population density, can have drastic cascading effects on the equilibrium of many other populations in the ...
Population dynamics[edit]. Main article: Population dynamics of fisheries. Population dynamics describes the growth and decline ... Wilderbuera, Thomas K and Zhang, Chang Ik (1999) Evaluation of the population dynamics and yield characteristics of Alaska ... The population dynamics of fisheries has been traditionally used by fisheries scientists to determine sustainable yields.[28][ ... Beverton, R. J. H.; Holt, S. J. (1957). On the Dynamics of Exploited Fish Populations. Fishery Investigations Series II Volume ...
Population dynamics[edit]. The population density of the marsh rice rat usually does not reach 10 per ha (4 per acre).[158] The ... Population dynamics of Oryzomys palustris and Microtus pennsylvanicus in Virginia tidal marshes (subscription required). ... Measurements of different populations of the marsh rice rat Population. n. Total length. Tail length. Hindfoot length ... Population size is usually largest during the summer and declines during winter,[159] although populations in Texas and ...
Population dynamics[edit]. Between April 2010 and January 2019, there were an estimated 1,745 births and 1,605 deaths in the ... In recent years there has been concern that the alewife population will not support the salmon population,[9] especially as the ... "Population and Housing Unit Estimates". Retrieved March 26, 2020.. *^ "U.S. Decennial Census". United States Census Bureau. ... 0.76% of the population were Hispanic or Latino of any race. 36.4% were of German, 23.8% Belgian, 9.7% Czech, 6.3% Polish and ...
Population dynamics[edit]. In the general study of cultural change and population dynamics, a whole system displays complex ... Population crises and cycles in history Archived 2011-04-05 at the Wayback Machine., A review of the book Population Crises and ... Populations Crises and Population Cycles Archived 2013-05-27 at the Wayback Machine., Claire Russell and W.M.S. Russell ... Several key features of human societal collapse can be related to population dynamics[13] ...
Population - See stock. Population dynamics - The study of fish populations and how fishing mortality, growth, recruitment, and ... See population dynamics. Socioeconomics - A word used to identify the importance of factors other than biology in fishery ... Virtual population analysis (VPA) - an analysis of fish population numbers that uses the number of fish caught at various ages ... Population model - a hypothesis of how a population functions. It often uses mathematical descriptions of growth, recruitment ...
population and agricultural growth. *population dynamics. *population health, economic implications of. *Portugal, economics in ...
long-term population dynamics. *global environmental change. *the prevalence and persistence of hunger ... Population Growth and Agricultural Change in Africa. University of Florida Press.. *Turner, B.L. II, W.C. Clark, R.W. Kates, J. ... Kates's research focused on long-term trends in environment, development, and population, and he is particularly known for his ... Humans cannot "adapt" or, in Kates's language, "adjust" successfully to hazards when a population is highly vulnerable or even ...
"Ecology, Population Dynamics, and Fisheries: FishBase". IFM-GEOMAR, Kiel. Archived from the original on 24 March 2012. ... ecology and population dynamics as well as reproductive, metabolic and genetic data. There is access to tools such as trophic ...
2015 Population Dynamics of Bark Beetles. *^ Kirkendall, L.R., D.S. Kent, and K.F. Raffa. 1997. Interactions among males, ... A semisocial population has the features of communal and quasisocial populations, but they also have a biological caste system ... Sociality is the degree to which individuals in an animal population tend to associate in social groups (gregariousness) and ... Furey, R. E. (1998). "Two cooperatively social populations of the theridiid spider Anelosimus studiosus in a temperate region ...
Charlesworth B, Charlesworth D (1983). "The population dynamics of transposable elements". Genet. Res. 42: 1-27. doi:10.1017/ ... The idea of spreading a gene into a population as a means of population control is actually quite old, and models for the ... "Population dynamics of PIWI-interacting RNAs (piRNAs) and their targets in Drosophila". Genome Research. 20 (2): 212-27. doi: ... and follow a Red Queen dynamics, which may mask the presence of selfish genetic elements in a population. Hybrid offspring, on ...
Elbrächter, M.; Qi, Y.Z. (1998). "Aspects of Noctiluca (Dinophyceae) population dynamics". In Anderson, Donald Mark; Cembella, ... Blooms are often red in coastal areas of the North Sea.[5] Green tides result from N. scintillans populations having green- ... N. scintillans populations can exhibit high concentrations due to high concentrations of the plankton on which they feed, which ... long-term dynamics, relationships with temperature and eutrophication, and role in the food web". Journal of Plankton Research ...
... distribution and population dynamics". Humangenetik. 3 (3): 189-234. doi:10.1007/BF00273124. PMID 6074385.. ... In most populations ovalocytosis is rare, but South-East Asian ovalocytosis (SAO) occurs in as many as 15% of the indigenous ... In many African populations the AS frequency is about 20%, and a fitness superiority over those with normal hemoglobin of the ... 72% of the island population were found to be Duffy-negative. P. vivax positivity was found in 8.8% of 476 asymptomatic Duffy- ...
Over the past five years, the population has increased by 30 thousand: since 2013, there has been a positive dynamics of ... In the age structure of the city's population, a large proportion of the population is older than the working age, which is ... "City Population.de. August 8, 2020. Retrieved September 1, 2020.. *^ В. В. Постников. (V. V. Postinkov.) "К осмыслению названия ... The city is located around the Golden Horn Bay on the Pacific Ocean, with a population of 606,561 residents,[11] up to 812,319 ...
Slough, B. G.; Mowat, G. (1996). "Lynx population dynamics in an untrapped refugium". The Journal of Wildlife Management. 60 (4 ... "DNA reveals high dispersal synchronizing the population dynamics of Canada lynx". Nature. 415 (6871): 520-522. doi:10.1038/ ... Snowshoe hare populations in Alaska and central Canada undergo cyclic rises and falls-at times the population densities can ... contiguous United States distinct population segment. version 1.0 (PDF) (Report). Contiguous United States Distinct Population ...
Demography and population dynamics of prairie dogs. In: Uresk, Daniel W.; Schenbeck, Greg L.; Cefkin, Rose, tech coords. 8th ... Social behavior, social organization, and population dynamics in a black-tailed prairie dog town in the Black Hills of South ... Home range and population density[edit]. The home range and territorial boundaries of black-tailed prairie dogs are determined ... Population density and growth are influenced by habitat quality [9] and are restricted by topographic barriers, soil structure ...
Cousens, Roger; Mortimer, Martin (1995). Dynamics of Weed Populations. Cambridge: Cambridge University Press. ISBN 978-0-521- ... Small, Michael (2012). Dynamics of Biological Systems. Boca Raton, FL: CRC Press. ISBN 978-1-4398-5336-8.. ... Biosphere , Ecosystem , Community (Biocoenosis) , Population , Organism , Organ system , Organ , Tissue , Cell , Organelle , ... forming clonal populations of identical individuals.[121] Durum wheat is a fertile tetraploid allopolyploid, while bread wheat ...
Elkinton, J. S.; A. M. Liebhold (1990). "Population dynamics of gypsy moth in North America". Annual Review of Entomology. 35: ... On the other hand, avian predation and invertebrate predation show only small effects on the population dynamics of the gypsy ... A population of gypsy moths will exist for many years in low densities. When the population enters the release phase, it ... Anastatus disparis is the only species that is known to occasionally affect the population dynamics of the gypsy moth. ...
Harold F. Levison; Luke Donnes (2007). "Comet Populations and Cometary Dynamics". In Lucy Ann Adams McFadden; Lucy-Ann Adams; ... Horner, J.; Evans, N.W.; Bailey, M. E. (2004). "Simulations of the Population of Centaurs I: The Bulk Statistics". Monthly ... In times past, bright comets often inspired panic and hysteria in the general population, being thought of as bad omens. More ... However, this represents only a tiny fraction of the total potential comet population, as the reservoir of comet-like bodies in ...
"Comet Populations and Cometary Dynamics". In McFadden, Lucy-Ann Adams; Weissman, Paul Robert; Johnson, Torrence V. (eds.). ... Some dynamics in the disk, such as dynamical friction, are necessary to allow orbiting gas to lose angular momentum and fall ... Dynamics of Comets: Their Origin and Evolution. Astrophysics and Space Science Library, Volume 115. 115. Springer Netherlands. ... and a population whose perihelia are close enough that Neptune can still disturb them as it travels around the Sun (the ...
Levison, Harold F.; Donnes, Luke (2007). "Comet Populations and Cometary Dynamics". In McFadden, Lucy-Ann Adams; Weissman, Paul ... dynamics, and geology. Three-dimensional computer simulations indicate the major structural features observed on cometary ...
"Dynamics of the Arctic fox population in Sweden". Annales Zoologici Fennici. 32: 55-68.. ... The other threatened population is the one in Fennoscandia (Norway, Sweden, Finland, and Kola Peninsula). This population ... The Fennoscandian population thus numbers around 140 breeding adults. Even after local lemming peaks, the Arctic fox population ... The populations are especially vulnerable during the years when the prey population crashes, and uncontrolled trapping has ...
Loery, G.; Nichols, J. D. (1985). "Dynamics of a Black-capped Chickadee population, 1958-1983". Ecology. 66 (4): 1195-1203. doi ... The IUCN classifies the black-capped chickadee as least concern due to its wide distribution and large populations.[1] In ... Three chickadee populations were observed at three different sites over 8 years, and all of them produced vocalizations that ... Singing contests are a way male chickadees decide who in a population gets to mate. When a male loses a contest, particularly a ...
Roossinck, M. J. (2011). "Changes in population dynamics in mutualistic versus pathogenic viruses". Viruses. 3: 12-19. doi: ...
"Evolutionary History and Population Dynamics of Hepatitis E Virus". PLOS One. 5 (12): e14376. Bibcode:2010PLoSO...514376P. doi: ... A vaccine based on recombinant viral proteins was developed in the 1990s and tested in a high-risk population (in Nepal) in ... Pregnant women show a more severe course of infection than other populations. Liver failure with mortality rates of 20% to 25% ... these vaccines have not yet been produced or made available to susceptible populations in general.[citation needed] The ...
Gaines, M. S.; Rose, R. K. (1976). "The population dynamics of Microtus ochrogaster in eastern Kansas". Ecology. 57 (6): 1145- ... The Prairie vole resides in dry fields that contain a cover of grasses and weeds, the largest populations are typically found ... can be used to reduce vole populations. They can also be scared away by plastic ornaments that resemble natural predators. ...
ISBN 978-1-139-49425-0. "Population dynamics; birth, death and migration per region: Municipality 's-Gravenhage". StatLine. ... 2013 - Population: 505,856 municipality. 2014 March: International 2014 Nuclear Security Summit held in city. Population: ... Population: 463,826. 2004 - Police raid a safehouse of terrorist organization Hofstad Network. 2006 - The Hague Jazz fest ... 1919 - Population: 359,610. 1921 - Asta cinema opens. 1922 15 June: Museum Bredius founded. 22 July: International Permanent ...
"Population dynamics; birth, death and migration per region: Municipality Leiden". StatLine. Statistics Netherlands. 2014. ... Population: 119,800 municipality. 2017 - Asian Library opened by Queen Máxima of the Netherlands. Leiden history History of ... 1919 - Population: 61,408. 1923 - Jan van Houtbrug [nl] (bridge) built. 1928 - University Hospital built. 1940 - Town Hall ... Population: 103,046 municipality. 1984 - Leiden Bio Science Park development begins. 2003 - Henri Lenferink [nl] becomes mayor ...
"Population dynamics; birth, death and migration per region: Municipality Utrecht". StatLine. Statistics Netherlands. 2014. " ... 1950 - Population: 193,190. 1954 - Oudenrijn (section) and Zuilen become part of city.[citation needed] 1960 - Population: ... 1919 - Population: 138,334. 1921 - Centraal Museum established. 1924 - Rietveld Schröder House built in the De Stijl design ... 2000 - Population: 233,667. 2001 - Vleuten-De Meern becomes part of city.[citation needed] 2002 - Regio Randstad regional ...
ISBN 978-90-6450-347-4. "Population dynamics; birth, death and migration per region: Municipality 's-Hertogenbosch". StatLine. ... 2000 - Population: 129,034 municipality. 2005 - Brabants Historisch Informatie Centrum [nl] established. 2013 - Population: ... 1919 - Population: 38,067. 1925 - Centraal Noordbrabants Museum [nl] opens on Bethaniëstraat [nl]. 1926 - Sportpark De Hooge ... 1853 - Theatre built on the Papenhulst [nl]. 1866 - Population: 24,201. 1868 - 's-Hertogenbosch railway station opens. 1874 - ' ...
Anderson, Charles H.; Eliasmith, Chris (2004). Neural Engineering: Computation, Representation, and Dynamics in Neurobiological ... which gives rise to the population model of neural networks. While many neurotheorists prefer such models with reduced ... Eliasmith, Chris; Anderson, Charles H. (2003). Neural engineering: Representation, computation, and dynamics in neurobiological ... Gerstner, W.; Kistler, W.; Naud, R.; Paninski, L. (2014). Neuronal Dynamics. Cambridge, UK: Cambridge University Press. ISBN ...
"Dynamic energy budget representations of stoichiometric constraints on population dynamics" (PDF). Ecology. 85 (5): 1230-1243. ... Trophic dynamics[edit]. The trophic level concept was introduced in a historical landmark paper on trophic dynamics in 1942 by ... Theoretical population biology. 16: 144-158. doi:10.1016/0040-5809(79)90010-8. PMID 538731. Archived from the original (PDF) on ... 2004). "Detritus, trophic dynamics and biodiversity". Ecology Letters. 7 (7): 584-600. doi:10.1111/j.1461-0248.2004.00606.x.. ...
... population dynamics: *75% of respondents said they were White or Caucasian and no other race; ... Population as of. 1990 Census[4]. Population as of. 2000 Census[4]. Change. Percent. change. ... Changes in populationEdit. Regionally, the South and West experienced the bulk of the nation's population increase, 14,790,890 ... The populations of the District of Columbia and Puerto Rico are excluded from the apportionment population because they do not ...
Regardless, I think your problem is not with the dynamics of Wikipedia, but the dynamics of the world. You may be right that a ... Also, the combined population of those three countries is roughly 1.5 billion. Hamedog, we need someone who knows cricket (like ... large population). The next closet person is still quite far back (Murali on 674).--HamedogTalk,@ 05:46, 26 December 2006 (UTC ...
General population. Education of the general public about the risk factors for Ebola infection and of the protective measures ... "Transmission dynamics and control of Ebola virus disease (EVD): a review". BMC Med. 12 (1): 196. doi:10.1186/s12916-014-0196-0 ... decline in tracking indices of observed chimpanzee populations in the 420 km2 Lossi Sanctuary between 2002 and 2003.[243] ... and that outbreaks result from transmission between viral reservoirs and animal populations.[243] ...
Hamernik, R. P., & Ahroon, W. A. (1998). Interrupted noise exposures: Threshold shift dynamics and permanent effects. [Article ... This factor is particularly interesting due to the fact that a large population of people listen to music while exercising. ...
... the operation of selection and the dynamics of populations. 2014. John Sutherland. for his novel and convincing work on ... This means evolution, population biology, organismal biology and biological diversity. It was first awarded in 1890. It comes ... For his research on the population biology and evolution of plants which has greatly improved understanding of the adaptation ... In recognition of his distinguished work on selection in age-structured populations, extending the theory to the evolution of ...
"Structure and Dynamics of Supercell Thunderstorms". National Weather Service. National Oceanic and Atmospheric Administration. ... but in the years since has been surpassed by several others if population changes over time are not considered. When costs are ... dynamics, and creation.[45] Tornadoes also produce a detectable seismic signature, and research continues on isolating it and ... Reasons for this include the region's high population density, poor construction quality, and lack of tornado safety knowledge. ...
For example, in the U.S., reducing the deer population to levels of 8 to 10 per square mile (from the current levels of 60 or ... "Spatial dynamics of lyme disease: a review" (PDF). EcoHealth. 5 (2): 167-95. CiteSeerX 10.1.1.580.8928. doi:10.1007/s10393-008 ... The winter tick which has affected moose populations in the 21st century is not a carrier of Lyme.[281] ... Lyme and other deer tick-borne diseases can sometimes be reduced by greatly reducing the deer population on which the adult ...
... in a molecular dynamics (MD) simulation study". Biophys. Chem. 120 (1): 1-9. doi:10.1016/j.bpc.2005.10.002. PMID 16253415.. ... "Impact of dietary and lifestyle factors on the prevalence of hypertension in Western populations". European Journal of Public ...
A general hierarchical model can integrate disturbance, dispersal and population dynamics. Based on factors of dispersal, ... Blackith, R. E. (1958). Nearest-Neighbour Distance Measurements for the Estimation of Animal Populations. Ecology. pp. 147-150. ... Populations within a species are translocated through many methods, including dispersal by people, wind, water and animals. ... Due to limited resources, populations may be evenly distributed to minimize competition,[9] as is found in forests, where ...
Multigene haplotypes following standard dynamics only exist in robust populations for a short time, the average distance ... Recombination dynamics[edit]. Each person has unique chromosomes, unless they are identical twins. These unique chromosomes are ... This dynamic can change if the population expands rapidly from a few individuals that lived in isolation as long as other ... A1::DQ2 does not follow the expected dynamics. Other haplotypes exist in the region of Europe where this haplotype formed and ...
The dynamics of the cooling process is governed by the equation J. c. (. T. c. (. t. ). ). =. −. c. V. (. T. c. (. t. ). ). d. ... The quantum adiabatic condition is therefore equivalent to no net change in the population of the instantaneous energy levels. ... The dynamics of a system observable represented by the operator, O. {\displaystyle O}. , has the form: d. O. d. t. =. i. ℏ. [. ... Reduced dynamics is an equivalent description of the systems dynamics utilizing only systems operators. Assuming Markov ...
Schaub, M; Gimenez, O.; Sierro, A.; Arlettaz, R (2007). "Use of Integrated Modeling to Enhance Estimates of Population Dynamics ... confidence interval for the population size N can be obtained as: K. +. n. −. k. −. 0.5. +. (. K. −. k. +. 0.5. ). (. n. −. k. ... Given those conditions, estimated population size is: N. ^. =. K. n. k. ,. {\displaystyle {\hat {N}}={\frac {Kn}{k}},}. ... which combines mark-recapture data with population dynamics models and other types of data. The integrated approach is more ...
a b c d e f The Kurdish Population by the Kurdish Institute of Paris, 2017 estimate. The Kurdish population is estimated at 15- ... "Exploring the roots and dynamics of Kurdish ethno-nationalism in Turkey" (PDF). Nations and Nationalism. Bilkent University ... "Population/Census" (PDF). geostat.ge.. *^ "Number of resident population by selected nationality" (PDF). United Nations. ... Population. Main article: Kurdish population. The number of Kurds living in Southwest Asia is estimated at between 30-45 ...
... "formation of macroscopic population dynamics that shapes the patterns of activity of the contributing individuals", applicable ... Freeman introduces what he calls "circular causality" to "allow for the contribution of self-organizing dynamics", the " ...
"Population dynamics and occurrence of Spodoptera frugiperda host strains in southern Florida". Ecological Entomology. 29 (5): ... It has been shown that direct predation can cause significant losses to caterpillar populations.[4] The larva's main defense ... but in high populations they will lay them just about anywhere.[15] In warm weather, the eggs will hatch into larvae within a ...
Population cycle. *Population dynamics. *Population modeling. *Population size. *Predator-prey (Lotka-Volterra) equations ... When hunters caused sea otter populations to decline, an ecological release of sea urchin populations occurred. The sea urchins ... The prey is then able to overexploit its own food resources, until the population numbers decrease in abundance, which can lead ... No longer having food to eat, the sea urchins populations became locally extinct as well. Also, since kelp forest ecosystems ...
... an effect absent in the human-reared population. Results in both populations are consistent with a process of canalization of ... Cultural Dynamics. 2: 209-237. doi:10.1177/092137408900200205.. ... A control group in each population saw no model. In both ...
Teignbridge in Devon had the largest population gain with 26.3% and Devon as whole grew by 17.6%. Population falls occurred in ... and BAe Dynamics, who had made nose cones for aircraft including Concorde), and Schneider Electric UK (Drayton Controls, market ... The population of the South West is about five million.[15]. TransportEdit. The region lies on several main line railways. The ... The population in the region with the highest obesity level is Sedgemoor in Somerset, with 73.4%, the fifth in the UK. North ...
Malthus, Thomas Robert (1798). An Essay on the Principle of Population. London: J. Johnson.. • Persky, Joseph (Autumn 1990). " ... Labor economics seeks to understand the functioning and dynamics of the markets for wage labor. Labor markets function through ... Malthus, Thomas (1798). An Essay on the Principle of Population. J. Johnson Publisher.. ... He posited that the growth of population and capital, pressing against a fixed supply of land, pushes up rents and holds down ...
Simon A, Bigras Poulin M, Rousseau AN, Dubey JP, Ogden NH «Spatiotemporal dynamics of Toxoplasma gondii infection in Canadian ... Evidence from a Population-Representative Birth Cohort» (en anglès). PLoS One, 2016 Feb 17; 11 (2), pp: e0148435. DOI: 10.1371/ ...
About 7% of the US population is addicted to alcohol. In rats exposed to alcohol for up to 5 days, there was an increase in ... "Distribution and dynamics of chromatin modification induced by a defined DNA double-strand break". Current Biology. 14 (19): ... Cigarette smokers (about 15% of the US population) are usually addicted to nicotine.[106] After 7 days of nicotine treatment of ... Methamphetamine addiction occurs in about 0.2% of the US population.[111] Chronic methamphetamine use causes methylation of the ...
Genome assembly and validation; mathematical modeling and algorithm development; population genetics; applied statistical and ... chromatin dynamics; structural biology; advanced proteomics; mass spectrometry; advanced microscopy. ... that enhancements and deletions of genetic material called copy number variations are common across the human population;[39] ...
Quantum dynamics. *Quantum electronics. *Quantum error correction. *Quantum imaging. *Quantum information. *Quantum key ...
Population ecology and structural dynamics of walleye pollock (Theragra chalcogramma). Dynamics of the Bering Sea, 581-614. ... Oehme, G. (1969). Population trends in the white-tailed sea eagle in North Germany. Peregrine Falcon Populations: Their Biology ... The largest population in Europe is found along the coast of Norway.[1][263] The Norwegian population in 2008 was claimed to ... Population and Development Review, 27(2), 381 pp. *^ Maurer, G., Russell, D. G., Woog, F., & Cassey, P. The eggs of the extinct ...
The Afro-Asian Population Exemplifies Park's Definition of Marginalization, in That They Are the "product of Human Migrations ... Christoph Bochinger, Jörg Rüpke (ed.) (2017). Dynamics of Religion: Past and Present. Proceedings of the XXI World Congress of ... of the population identified as black, 40% as pardo, and 55% as white. Essentially most of the black population was absorbed ... Brazilian Population, by Race, from 1872 to 1991 (Census Data)[164]. Ethnic group. White. Black. Brown. Yellow (Asian). ...
Iliffe, John (1989). "The Origins of African Population Growth". The Journal of African History. 30 (1): 165-69. doi:10.1017/ ... "Imperialism and the Victorians: The dynamics of territorial expansion." English Historical Review (1997) 112#447 pp. 614-42. ... "Africa's population now 1 billion" Archived 2011-04-27 at the Wayback Machine. AfricaNews. August 25, 2009. ... In the 20th century, Africa saw the biggest increase in its population due to lessening of the mortality rate in many countries ...
The point of contact between the older population and the newer population is ideally a stepped cline, but due to dispersal ... N. H. Barton (1979). "The dynamics of hybrid zones". Heredity. 43: 341-359. doi:10.1038/hdy.1979.87.. ... These include positive assortative mating within populations, habitat selection of different populations and hybrid unfitness. ... The two populations then mate within an area of contact, producing 'hybrids' which contain a mixture of the alleles distinctive ...
Jan 2002). "Prevalence and risk factors of silent brain infarcts in the population-based Rotterdam Scan Study". Stroke. 33 (1 ... Treatment decision often involve complex ethical choices and can strain family dynamics.[36] ...
Some characteristics of populations that are of interest to biologists include the population density , the birthrate , and the ... Population Dynamics A population describes a group of individuals of the same species occupying a specific area at a specific ... Population Dynamics Encyclopedia of Population COPYRIGHT 2003 The Gale Group Inc.. POPULATION DYNAMICS. Population dynamics ... Population Dynamics Animal Sciences COPYRIGHT 2002 The Gale Group Inc.. Population Dynamics. A population describes a group of ...
Dispersal is a key process influencing population dynamics and gene flow in species. Despite this, little is known about ... Sprawling and diverse: The changing U.S. population and implications for public lands in the 21st Century. Publications Posted ... RMRS scientists recently completed a 10 year study of a population of threatened Mexican spotted owls (Strix occidentalis ... This chapter focuses on applications of landscape genetics for understanding connectivity of terrestrial animal populations. It ...
Population Dynamics Option. The Population Dynamics Option (PDO) is an option for graduate students in Sociology, Economics, ... Population Dynamics Seminar series) and periodic seminars and trainings related to population issues. Most events are free and ... The Centre on Population Dynamics (CPD) is a community of scholars dedicated to creating and disseminating new knowledge on the ... Centre on Population Dynamics. Peterson Hall Building. 3460 McTavish Street Montreal, Quebec, H3A 0E6. ...
Population Dynamics. Analysis of the factors affecting human population growth and distribution, migration patterns, and the ... relationship between economic activity and population trends. Prerequisites: SOC 001; SOC 090 or SOC 100 or SOC 101. ...
Population Dynamics Program Option. The Population Dynamics Option (PDO) is a cross-disciplinary, cross-faculty graduate ... The Centre on Population Dynamics (CPD) is a community of scholars dedicated to creating and disseminating new knowledge on the ... Centre on Population Dynamics. Peterson Hall Building. 3460 McTavish Street Montreal, Quebec, H3A 0E6. ... The research conducted by members of the Centre on Population Dynamics lies within several key areas of demographic research: ...
The Centre on Population Dynamics brings together leading population researchers from disciplines across social science and ... Centre on Population Dynamics. Peterson Hall Building. 3460 McTavish Street Montreal, Quebec, H3A 0E6. ... Associate Members Members Department University Population Dynamics-related Research Interests Vissého Adjiwanou ...
Content: This course deals with the mathematics behind the dynamics of populations; both populations of free-living organisms ( ... Research into the dynamics of ecological populations allows us to understand the conservation of endangered species, make ... The focus of the course will be how mathematical models can help us both predict the future behaviour of populations and ... predictions about the effects of global climate change and understand the population fluctuations observed in the natural world ...
The characteristics of natural populations result from different stochastic and deterministic processes that include ... Quer J, Huerta R, Novella IS, Tsimring L, Domingo E, Holland JJ (1996) Reproducible nonlinear population dynamics and critical ... Escarmís C., Lázaro E., Manrubia S.C. (2006) Population Bottlenecks in Quasispecies Dynamics. In: Domingo E. (eds) Quasispecies ... As a consequence, in any population the fixation of mutations is accelerated when environmental conditions cause population ...
... dc.contributor.author. Regional Committee for the Western Pacific, 019. ...
"Fisheries Management Under Cyclical Population Dynamics," University of California at San Diego, Economics Working Paper Series ... "Fisheries Management Under Cyclical Population Dynamics," Environmental & Resource Economics, Springer;European Association of ...
1968)‎. Health aspects of population dynamics (‎Resolution)‎. Manila : WHO Regional Office for the Western Pacific. http://www. ...
MAE: Population dynamics. Within species, there is variation among populations, groups of animals in a particular area that ... Animal Ecology contributes to the fields of population genetics and population ecology and studies how population dynamics ... To study population dynamics, Marine Animal Ecology performs field monitoring. and performs molecular techniques. . With a ... Population dynamics on small islands. Seabirds are not doing so well. Especially on small islands such as those present in the ...
Complex Population Dynamics. Principal Investigators:. William W. Murdoch, and Peter Turchin. Population cycles and other ... Population cycles and other complex population dynamics occur in a wide range of taxa and environments, including temperate and ... Evolutionary and population dynamics of host-parasitoid interactions. Researches on Population Ecology. Vol: 41. Pages 81-91. ... The macroecology of population dynamics: Taxonomic and biogeographic patterns in population cycles. Ecology Letters. Vol: 1. ...
2014 World Population Data Sheet. August 2014: Datasheet The 2014 World Population Data Sheet offers up-to-date demographic, ... World Population Digital Visualization 2014. Explore current and projected population by region and country. And look at ... 2014 World Population Graphics. These interactive graphics reflects data from PRBs 2014 World Population Data Sheet. ... World Population Digital Visualization 2014. August 2014: Datasheet Explore current and projected population by region and ...
This paper focuses on two major elements of Chinas population dynamics-the rising proportion of workers in the population and ... suggests that the benefits of Chinas population dynamics during the last three decades have been overstated. ... We measure the mechanical contributions of these dynamics to per capita income as revealed by growth decompositions, before ... capita income and productivity growth in a series of regressions that include the growth of the working-age to total population ...
This research develops a continuous-time optimal growth model that accounts for population dynamics resembling the historical ... The article also investigates the emergence of damped or persistent cyclical dynamics.,/p, ... Population dynamics and economic development. Andrea Caravaggio 1, , Luca Gori 2,, and Mauro Sodini 3, ... Keywords: Economic development, population dynamics, indeterminacy. Mathematics Subject Classification: C61; C62; J1, J22; O41 ...
Population Dynamics for advanced students and those interested in mathematical modelling. ... Population Dynamics - Part 1. Age 16 to 18 Challenge Level: First in our series of problems on population dynamics for advanced ... Population Dynamics - Part 3. Age 16 to 18 Challenge Level: Third in our series of problems on population dynamics for advanced ... Population Dynamics - Part 5. Age 16 to 18 Challenge Level: Fifth in our series of problems on population dynamics for advanced ...
Population Dynamics. Population dynamics is the study of population size and factors that affect animal abundance. These ... A population model is then used to determine total population size. This is done by calculating how many adults in a population ... The Baffin Bay population was estimated to be ≈ 170 000 animals in 2013. This population summers in bays and fjords of the High ... The East Greenland population is the third population and was estimated to number ≈6400 whales in 2008. Its summer range ...
Population Dynamics.. 4. Republic of Maldives Population & Housing Census 2014.. Statistical Release: 1 Population & Households ... Maldives Population Dynamics Skip to content Close Search Search for:. ... 1. John F. May, Maldives Population Dynamics: Policy Prospects for Human Growth and Opportunity (Male: UNFPA Maldives Country ... The Government of Maldives last addressed population and development issues in its 2004 Population Policy of the Maldives, as ...
The following differential equations can be used to describe the basic dynamics of the interaction between and : where the ... Antimicrobial Resistance within Host: A Population Dynamics View. Chunji Huang1 and Aijun Fan2 ... A. M. Garber, "Antibiotic exposure and resistance in mixed bacterial populations," Theoretical Population Biology, vol. 32, no ... To study the dynamics of system (1), we first show that that model (1) is biologically well behaved and dissipative; that is, ...
Dynamics and the Metropolitan Policy Program jointly hosted an NICHD funded Agent Based Modeling and Spatial Population ... Dynamics Workshop at the Brookings Institution. Researchers from across the country attended the workshop to discuss current ... Agent-Based Modeling and Spatial Population Dynamics Workshop. 12:00 PM. - 5:00 PM. The Brookings Center on Social and Economic ... Dynamics and the Metropolitan Policy Program jointly hosted an NICHD funded Agent Based Modeling and Spatial Population ...
... Guest Editors: Weiming Wang, Yun Kang, Malay Banerjee, and ... Advanced Nonlinear Dynamics of Population Biology and Epidemiology, Weiming Wang, Yun Kang, Malay Banerjee, and Kaifa Wang ... Antimicrobial Resistance within Host: A Population Dynamics View, Chunji Huang and Aijun Fan Research Article (5 pages), ... Nonlinear Dynamics of a Nutrient-Plankton Model, Yapei Wang, Min Zhao, Chuanjun Dai, and Xinhong Pan Research Article (10 pages ...
What Influences Population Size?. Over the years, Adams has been able to connect population size of the Denali Herd with winter ... Adams has focused on annual assessments of the herds basic population dynamics (herd size and trend, adult sex composition, ... Since 1975, caribou have been radiocollared in Denali to study their population dynamics and movements. Layne Adams ... Tags: caribou population monitoring denali fact sheet research wildlfe biology biological science ...
and (ii) the total number of larvae produced in other populations y and dispersed to populations at time . The dynamics of the ... Marine population theory has relied mostly on the environment to explain the regional (,1,000 km) dynamics of populations. This ... S4 B, D, and F). This cross-scale interaction between local population dynamics and limited dispersal is a general property of ... Ecological processes can synchronize marine population dynamics over continental scales. Tarik C. Gouhier, Frédéric Guichard, ...
... and population dynamics (increasing population density) combine to produce "hotspots" of vulnerability. The concept is simple, ... What do we already know about the empirical linkages between population dynamics and climate change? How can we best ... Education is a major source of heterogeneity in population dynamics and also an important condition of socioeconomic ... incorporating this heterogeneity represents a considerable advance from the way population dynamics were integrated in earlier ...
Fast Variables in Stochastic Population Dynamics. Authors. * George William Albert Constable Series Title. Springer Theses. ... Currently, he is a postdoctoral researcher looking at the effects of spatial structure on population level dynamics in the ... While the introductory and background chapters form an excellent primer to the theory of stochastic population dynamics, the ... Features a clear introduction to stochastic population dynamics, making the thesis easily accessible to non-experts ...
We estimated the population consequences to an inferior competitor from interactions with a superior competitor that also is an ... Population dynamics of a damselfish: Effects of a competitor that also is an indirect mutualist. *Holbrook S ... We estimated the population consequences to an inferior competitor from interactions with a superior competitor that also is an ... Anemonefish have an indirect positive effect on dascyllus populations due to the faster growth that anemones experience when ...
Demographic dynamics and kinship in anthropological populations. E. A. Hammel. PNAS February 8, 2005 102 (6) 2248-2253; https ... Each run lasted 1,000 years in addition to the 100 years of experience embedded in the starting population. A population and ... The following negative fertility change applies to the enlarged population, producing a population reduction that is less than ... The resulting population was used as the starting population in all experiments. In Table 1, "w7.stat" means that in the period ...
Welcome to the Population Dynamics Branch. Photo Credit: Victoria Boucher Photography. The Population Dynamics Branch studies ...
By 2050, nearly 63 per cent of the total population of Southeast Asia is expected to live in urban areas. Not only is ... Between 1950 and 2000, the total population of West Africa increased fourfold, with almost one third now living in urban ... from market nodes to providers of services and goods and non-farm employment to their own population as well as that of the ... and effective policy approaches in addressing food security and nutrition in the context of changing rural-urban dynamics. The ...
  • Crow JF, Kimura M (1970) An introduction to population genetics theory. (springer.com)
  • Marine Animal Ecology contributes to the fields of population genetics and population ecology and studies how population dynamics change over time and space. (wur.nl)
  • Survival, migration patterns and population genetics will be studied and compared with patterns of large populations. (wur.nl)
  • Marine lakes can thus be used to use population genetics to study population differentiation and demographic history. (wur.nl)
  • Drivers of marine biodiversity: population genetics and community assembly. (wur.nl)
  • While the introductory and background chapters form an excellent primer to the theory of stochastic population dynamics, the techniques developed can be applied to systems exhibiting a separation of timescales in a variety of fields including population genetics, ecology and epidemiology. (springer.com)
  • This project examined aspects of the Laysan teal ecology including population dynamics and reintroduced biology, behavior, reproductive success, population genetics, and habitat use on Laysan Island and the reintroduced population on Midway Atoll NWR. (usgs.gov)
  • Blue crabs are an ecologically and economically important species and there are many possible applications of the research including connections with fisheries management, food web analysis, population genetics, and research into the effects of the Deepwater Horizon oil spill. (tulane.edu)
  • The frequency distribution of surnames turns out to be a relevant issue not only in historical demography but also in population biology, and especially in genetics, since surnames tend to behave like neutral genes and propagate like Y chromosomes. (mdpi.com)
  • R. Bürger , Perturbations of positive semigroups and applications to population genetics, Mathematische Zeitschrift , 197 (1988), 259-272. (aimsciences.org)
  • The editors include not only a wide variety of theoretical approaches, but also a broad range of experimental and field studies, with chapters written by renowned experts in community ecology, ecological modeling, population genetics, and conservation biology. (powells.com)
  • In addition to providing new insights into well-known topics such as migration, the authors also introduce some less familiar subjects, including bacterial population genetics and ecotoxicology. (powells.com)
  • Marsh L.K. (2003) Genetics and Population Dynamics. (springer.com)
  • Determining the relative importance of local and regional processes for the distribution of population abundance is a fundamental but contentious issue in ecology. (pnas.org)
  • Currently, he is a postdoctoral researcher looking at the effects of spatial structure on population level dynamics in the Ecology and Evolutionary Biology Department at Princeton University. (springer.com)
  • Due to the remoteness of Laysan Island, few researchers or naturalists have studied the species and little was known of its ecology or population status. (usgs.gov)
  • Translocation - Apply data gathered on foraging ecology, population dynamics, habitat use, and behavior to make recommendation on best methods, timing, and ecosystem restoration required for the highest probability of a successful translocation and population persistence. (usgs.gov)
  • The formula can be read as follows: the rate of change in the population (dN/dT) is equal to growth (aN) that is limited by carrying capacity (1-N/K). From these basic mathematical principles the discipline of population ecology expands into a field of investigation that queries the demographics of real populations and tests these results against the statistical models. (wikipedia.org)
  • The field of population ecology often uses data on life history and matrix algebra to develop projection matrices on fecundity and survivorship. (wikipedia.org)
  • The concept is commonly used in insect population ecology or management to determine how environmental factors affect the rate at which pest populations increase. (wikipedia.org)
  • A graphic model illustrating the complexity of caribou population ecology under the influences of a changing climate. (nps.gov)
  • Insect population dynamics meets ecosystem ecology: effects of he. (ingentaconnect.com)
  • Population Dynamics Worksheet Answers Population Dynamics Worksheet Answers Population Dynamics Worksheet Answers Population Dynamics Ecology Published February 2018 www.BioInteractive.org Page 3 of 8 Click & Learn Educator Materials Solving Students construct a population pyramid for their assigned country by graphing the percentage data onto the Pyramid Graph Paper. (ireggae.com)
  • Because of this, incorporating a full view of microbial dynamics is essential to explaining the dynamics of plant-soil feedbacks and therefore plant community ecology. (nih.gov)
  • The research, published in the latest edition of the magazine Oecologia (Ecology), has made it possible to determine the relative importance of the area which the butterfly Iolana iolas inhabits, as well as the connectivity between the different areas of the habitat (at a maximum distance of two kilometres from each other) in a network of 75 patches (population centres) situated in the south of the province of Madrid (Chinchón). (innovations-report.com)
  • In 2011, the main focus of the workshop will be on 'Population Dynamics', more precisely on stochastic models for population dynamics in ecology and evolution, particularly with a view towards spatial models. (euro-math-soc.eu)
  • Within species, there is variation among populations, groups of animals in a particular area that interbreed. (wur.nl)
  • Synchrony can be induced by local intrinsic processes such as dispersal among populations and strong interactions with mobile predators or regional extrinsic processes such as spatially correlated environmental variability ( 1 ). (pnas.org)
  • Recent work has shown that when the processes that contribute to synchrony can be studied in isolation, be it via natural barriers to dispersal among populations ( 2 , 3 ) or experimental manipulation ( 4 ), synchrony patterns can be ascribed to their underlying cause. (pnas.org)
  • Beta-diversity analysis showed distinct clustering of samples, attributable to seemingly synchronous temporal transitions among populations (populations defined by 97% 16S rRNA gene sequence identity). (diva-portal.org)
  • If you go back to Population 101 you will remember that animal populations go up and down in relation to the access to and abundance of food and other necessary living resources (depending on the particular species). (cyburbia.org)
  • Young scientists learn about both exponential and logistic growth models in various animal populations. (ireggae.com)
  • The Denali Caribou Herd is ideal for studying natural factors that influence caribou populations because the herd ranges almost entirely within Denali (see map on reverse), where human harvests of large predators (wolf, grizzly bear, black bear) and their ungulate prey (sheep, moose, caribou) are minimal, so natural processes predominate. (nps.gov)
  • Our goal is to explain, within the limits of our present understanding, how the changing climate can be expected to influence caribou populations through its affect on these primary influences. (nps.gov)
  • Fisheries Management Under Cyclical Population Dynamics ," Environmental & Resource Economics , Springer;European Association of Environmental and Resource Economists, vol. 42(3), pages 379-410, March. (repec.org)
  • Evolution of recent economic-demographic modeling: A synthesis ," Journal of Population Economics , Springer;European Society for Population Economics, vol. 18(2), pages 275-300, June. (repec.org)
  • M. Iannelli and F. Milner, The Basic Approach to Age-Structured Population Dynamics: Models, Methods and Numerics , Springer, 2017. (aimsciences.org)
  • J. A. Metz and O. Diekmann, The Dynamics of Physiologically Structured Populations , Springer, 2014. (aimsciences.org)
  • A population describes a group of individuals of the same species occupying a specific area at a specific time. (encyclopedia.com)
  • Although this is straightforward in theory, determining population densities for many species can be challenging in practice. (encyclopedia.com)
  • The quadrat method is particularly suited to measuring the population densities of species that are fairly uniformly distributed over the habitat. (encyclopedia.com)
  • For example, it has been used to determine the population density of soil species such as nematode worms. (encyclopedia.com)
  • Research into the dynamics of ecological populations allows us to understand the conservation of endangered species, make predictions about the effects of global climate change and understand the population fluctuations observed in the natural world. (warwick.ac.uk)
  • Although population bottlenecks can occur in any species, their effects are more noticeable in organisms that form large and heterogeneous populations, such as RNA viral quasispecies. (springer.com)
  • The St. Lawrence Estuary population is at the southernmost limit of the species distribution. (gc.ca)
  • The population is listed as threatened under the Species at Risk Act (SARA). (gc.ca)
  • The Laysan teal has the most restricted range of any duck species and is especially vulnerable to extinction because of its small population size and vulnerability to climate change. (usgs.gov)
  • Small isolated populations are extremely vulnerable to extinction from stochastic events, natural disturbance, alien species, emerging diseases, and sea-level rise. (usgs.gov)
  • Wild translocation or the movement of wild birds to establish additional populations is a high priority of the U.S. Fish and Wildlife Service to reduce the species high extinction risks and recover the species. (usgs.gov)
  • Application of USGS research to restore a second population of the species has been viewed as one of the most successful applied research/conservation projects in decades. (usgs.gov)
  • Additional studies were added to help the USFWS develop techniques monitor the birds reproduction and survival, identify population crashes, identify causes of population crashes, and predict the impacts of climate change on the species. (usgs.gov)
  • Bringing together archaeological, paleoenvironmental, paleontological and genetic data, this book makes a first attempt to reconstruct African population histories from out species' evolution to the Holocene. (springer.com)
  • Modern human population dynamics, which involved multiple population expansions, dispersals, contractions and extinctions, played a central role in our species' evolutionary trajectory. (springer.com)
  • Populations of species in ecosystems are often constrained by availability of resources within their environment. (osti.gov)
  • Here we propose and model another redistribution mechanism driven by abrupt and severe collapses of the entire population of a single species freeing up resources for the remaining ones. (osti.gov)
  • Species abundances are characterized by a bimodal time-aggregated distribution with the lower peak formed by populations of recently collapsed or newly introduced species while the upper peak - species that has not yet collapsed in the current wave. (osti.gov)
  • We show that diversity wave dynamics is robust with respect to variations in the rules of our model such as diffusion between multiple environments, species-specific growth and extinction rates, and bet-hedging strategies. (osti.gov)
  • Biologists have just recently discovered this month the distribution of the butterfly Iolana iolas, one of the endangered species in the Madrid region whose population dynamics are determined by its host plant. (innovations-report.com)
  • The results of the study, prepared between 2003 and 2006, show that in the Iolana iolas and other species of monophagous butterflies (with clearly delimited habitat requirements), it is possible to predict the dynamics of their populations from the geometric variables of patches, "since most of the characteristics of the habitat are related to the patch area", explained Sonia García Rabasa, the main author of the article, to SINC. (innovations-report.com)
  • To predict the distribution patterns it has also been important to study the synchrony between populations: "The spatial study and population dynamics of butterflies may also affect the incidence and probability of the extinction of the species", García Rabasa pointed out. (innovations-report.com)
  • 1986). In the first phase, the species will try to adjust to modified habitats, while in the second phase, changes will occur in the demography of the population. (springer.com)
  • Para ello, fueron analizados 10884 ejemplares colectados en puntos de expendio de pescado y zonas de pesca aledaños a la ciudad de Puerto Leguízamo entre los años 2009 a 2017. (scielo.br)
  • The Centre on Population Dynamics (CPD) is a community of scholars dedicated to creating and disseminating new knowledge on the transformative demographic and health changes occurring across the globe. (mcgill.ca)
  • To study the relationship between antimicrobial resistance and the concentration of antibiotics, a competitive population dynamical model is proposed between the susceptible strain and the resistant strain with antibiotic exposure. (hindawi.com)
  • In this paper, based on the above mentioned mechanism of bacterial antibiotic resistance within the host, a competitive population dynamical model is proposed to explore the competitive interactions between the susceptible strain and the resistant strain with antibiotic exposure. (hindawi.com)
  • Here, we use spatial synchrony to compare the distribution of population abundance of the dominant mussel Mytilus californianus observed along the West Coast of the United States to that predicted by dynamical models undergoing different dispersal and environmental treatments to infer the relative influence of local and regional processes. (pnas.org)
  • In light of these recent developments, we relax the assumptions of demographic openness and local equilibrium dynamics and compare the distribution of population abundance, predicted by dynamical metapopulation models undergoing different dispersal and environmental treatments, to that of the dominant mussel Mytilus californianus , observed along the West Coast of the United States, to assess the relative importance of nearshore environmental heterogeneity and dispersal. (pnas.org)
  • Population dynamics is the type of mathematics used to model and study the size and age composition of populations as dynamical systems. (wikipedia.org)
  • In collaboration with state and federal agencies and nonprofit waterfowl groups, USGS Western Ecological Research Center ecologists are using a multipronged approach to study the population dynamics of geese in the Central Valley and determine how geese may be influencing local duck populations. (usgs.gov)
  • For example, it is expected that small asexual populations will accumulate mutations at a higher rate than larger ones. (springer.com)
  • Bachtrog D, Gordo I (2004) Adaptive evolution of asexual populations under Muller's ratchet. (springer.com)
  • Colato A, Fontanari JF (2001) Soluble model for the accumulation of mutations in asexual populations. (springer.com)
  • Here, we show how this form of "genetic draft" affects the forward-time dynamics of site frequencies in rapidly adapting asexual populations. (genetics.org)
  • We will also consider how closely population data from laboratory experiments and from studies of natural populations in the wild fit these models. (encyclopedia.com)
  • The characteristics of natural populations result from different stochastic and deterministic processes that include reproduction with error, selection, and genetic drift. (springer.com)
  • The theoretical literature on population cycles is enormous, but there has been no attempt to systematize it and to relate various postulated mechanisms to the oscillatory patterns observed in real populations. (ucsb.edu)
  • In marine systems, classical theory holds that the influence of demographic processes and dispersal is confined to local populations whereas the environment controls regional patterns of abundance. (pnas.org)
  • Failure to consider the indirect positive interaction in this system would lead to a gross underestimate of the strength of competition, and would not reveal the critical im- portance of the indirect mutualism in maintaining local populations of the inferior com- petitor. (mendeley.com)
  • However, in large populations many beneficial mutations can segregate simultaneously and the population can maintain substantial variation in fitness. (genetics.org)
  • The Brookings Center on Social and Economic Dynamics and the Metropolitan Policy Program jointly hosted an NICHD funded Agent Based Modeling and Spatial Population Dynamics Workshop at the Brookings Institution. (brookings.edu)
  • We show that dispersal among neighboring populations interacts with local demographic processes to generate characteristic patterns of spatial synchrony that can govern the dynamic distribution of mussel abundance over 1,800 km of coastline. (pnas.org)
  • Here, we show that in marine populations experiencing both intrinsic and extrinsic sources of synchrony, the shape of spatial synchrony patterns can be used to infer the cause of synchrony and explain the regional distribution of abundance. (pnas.org)
  • However, the competitive dynamics among microbes depends on the multidimensional costs of virulence and mutualism, the fine-scale spatial structure within plant roots, and active plant allocation and localized defense. (nih.gov)
  • Three researchers from the King Juan Carlos University in Madrid have therefore presented a line of study on the spatial structure and dynamics of the butterfly different to other quality characteristics in the habitat. (innovations-report.com)
  • In particular, population fluctuations constitute a stochastic process that may play a very relevant role in shaping the structure of populations. (springer.com)
  • We reveal synchronized fluctuations in the abundance of mussel populations across a whole continent despite limited larval dispersal and strong environmental forcing. (pnas.org)
  • Synchronized fluctuations in abundance among spatially segregated populations are common in nature and can be used to quantify and understand the distribution of abundance in space and time ( 1 ). (pnas.org)
  • The main objectives of my work are to examine (1) how arctic foxes use seasonally abundant foods and (2) how seasonal and annual fluctuations in food abundance affect foraging behaviours and population dynamics of arctic foxes. (thefreelibrary.com)
  • Population Processes Exhibiting Sub-Poisson Fluctuations and Odd-Even Effects. (routledge.com)
  • We found that bactericidal drugs induce population fluctuations, leading to stochastic population dynamics. (aps.org)
  • Our study reveals the stochastic population dynamics induced by antibiotics and how this stochasticity may be manipulated to facilitate bacterial clearance. (aps.org)
  • Population cycles show enormous variation in amplitude (from less than one to five orders of magnitude), period (from a single generation to 30-50 generations), and the strength of periodicity (ranging from noisy pseudoperiodic or apparently chaotic oscillations to an almost perfect periodicity). (ucsb.edu)
  • One type of open model, which allows for temporal variation in abundance but not explicit dynamics, is the simple model of temporary emigration (Kendall et al. (usgs.gov)
  • Over short timescales, this simple model may provide a sensible description of variation in population size over time. (usgs.gov)
  • Variation in the amount of resources, in this case the production of fruit from the host plant (Colutea hispanica), from which the larvae feed, and changes in population density during these years have made it possible to detect a high level of synchrony between different habitat fragments. (innovations-report.com)
  • However, corresponding insight into bacterioplankton dynamics at a temporal resolution relevant for detailed examination of variation and characteristics of specific populations within years is essentially lacking. (diva-portal.org)
  • Evolutionary Population Dynamics and Multi-Objective Optimisation Problems. (igi-global.com)
  • Previous investigations of population oscillations have utilized primarily two distinct approaches: potential mechanisms have been investigated with mathematical models, while data patterns have been investigated with phenomenological time-series analyses (cycles have also been investigated experimentally, but this approach is not part of our proposal because it falls outside of the scope of the research supported by the Center). (ucsb.edu)
  • Therefore, although genetic analyses indicate that most beluga in Hudson Bay belong to the same breeding population, they exhibit fidelity to specific aggregation areas in summer. (gc.ca)
  • This engagement often takes place in the context of Population Situation Analyses , common country assessments and the United Nations Development Assistance Framework. (unfpa.org)
  • CLICIM aims at the provision of evidence on the nexus between climate change and population dynamics in Africa. (europa.eu)
  • In this report, we analyse the relationship between climate change, population and migration in a selected territory within the Sahel - an already documented case of climate related migration. (europa.eu)
  • Firstly, the report provides a mapping of the population exposure to climate change in the selected territory over the period 1975-2015. (europa.eu)
  • This high level of synchrony is a risk to populations which might experience mass extinction in all areas experiencing adverse conditions, such as the effects of climate change. (innovations-report.com)
  • Promoting better market access and market performance for smallholder agricultural producers and the provision of access to better quality and lower price food for the majority of the world's population requires the strengthening of rural-urban linkages and putting 'place-based development' at. (fao.org)
  • Although this slow rate of decline satisfies the Millennium Development Goal (MDG) for TB, which is to ensure that the incidence rate is falling by 2015, the world's population is growing at about 2% per year, so the total number of new TB cases is still rising ( 1 ). (sciencemag.org)
  • Eradicating these injustices is not only a crucial human rights issues, it's also intricately connected with the world's population and the creation of a sustainable planet. (populationmedia.org)
  • The CPD brings together leading population researchers from disciplines across social science and health fields, including demography, economics, epidemiology, and sociology as well as computer science, geography and social work. (mcgill.ca)
  • The Population Dynamics Option (PDO) is an option for graduate students in Sociology, Economics, and Epidemiology, Biostatistics, and Occupational Health (EBOH) at McGill University. (mcgill.ca)
  • The Population Dynamics Option (PDO) is a cross-disciplinary, cross-faculty graduate program offered as an option within 5 existing Master's and doctoral programs in the departments of Sociology, Economics, and Epidemiology, Biostatistics, and Occupational Health (EBOH) at McGill University. (mcgill.ca)
  • Population dynamics overlap with another active area of research in mathematical biology: mathematical epidemiology, the study of infectious disease affecting populations. (wikipedia.org)
  • It will also appeal to anyone interested in the computational modeling of population dynamics. (springer.com)
  • apply a combination of modeling and statistical techniques to a number of data sets (Section IV) in an attempt to determine which of the possible theoretical mechanisms may be responsible for population oscillations in each particular case. (ucsb.edu)
  • Together, these population parameters, or characteristics, describe how the population density changes over time. (encyclopedia.com)
  • Seasonal dynamics in population characteristics of European bitte. (ingentaconnect.com)
  • In addition, cycles may involve not only the total population abundance, but also other aspects of dynamics, e.g. oscillations in age structure and complex spatio-temporal behaviors, such as synchronous oscillations or periodic traveling waves. (ucsb.edu)
  • Population dynamics is the study of population size and factors that affect animal abundance. (gc.ca)
  • Beluga abundance in the St Lawrence Estuary has been modeled using aerial surveys, which also provide information on the proportion of young animals in the population. (gc.ca)
  • Our study emphasizes the importance of dispersal and local dynamics for the distribution of abundance at the continental scale. (pnas.org)
  • The Population Dynamics Branch studies changes in distribution, abundance, and composition (size, sex, age, etc.) and is responsible for monitoring the abundance of fish stocks, measuring the impact of fishing activity, and evaluating biological aspects of the ecosystem. (noaa.gov)
  • The population was effectively annual, with a major decrease in adult fish abundance at the end of the reproductive period. (ingentaconnect.com)
  • In combination with the migratory data provided by the solar powered goose neck collars, USGS is using high-resolution remote sensing imagery of breeding areas to identify and calculate abundance for breeding colonies and estimate the contribution of each breeding colony to the wintering population in the Central Valley. (usgs.gov)
  • The abundance of sandeel varies from year to year, and thus, ecosystems can be highly sensitive to changes in the population dynamics of sandeel. (dtu.dk)
  • A wide spectrum of bacterioplankton dynamics was evident, where divergent temporal patterns resulted both from pronounced differences in relative abundance and presence/absence of populations. (diva-portal.org)
  • Rates of change in relative abundance calculated for individual populations ranged from 0.23 to 1.79 day(-1). (diva-portal.org)
  • The potential for large-scale transport, along with the difficulties associated with measuring larval dispersal, has prompted many studies to assume either completely closed (no exportation of larvae to other populations) or completely open (no coupling between larval production and recruitment) demography ( 5 , 6 , but see refs. (pnas.org)
  • We conclude that the study population had been a dispersal sink and that ceasing immigration combined with poor local survival caused the population to crash. (bioone.org)
  • Screening of NRY by a SNP assay in the dingoes of Australia Island as a population of feral dogs revealed restricted and similar dispersal patterns for sires and dams. (diva-portal.org)
  • A central issue in all models of adaptation involves how frequently beneficial mutations arise in the population. (genetics.org)
  • The accumulation of beneficial mutations on competing genetic backgrounds in rapidly adapting populations has a striking impact on evolutionary dynamics. (genetics.org)
  • THE effects of linkage between beneficial mutations in altering evolutionary dynamics and the structures of genealogies in adapting populations has been recognized for nearly a century, particularly in the context of the evolutionary advantage of sex ( Muller 1932 ). (genetics.org)
  • In both asexually reproducing organisms and in regions of low recombination in sexual organisms, the chance congregation of beneficial mutations on competing genetic backgrounds skews evolutionary dynamics. (genetics.org)
  • Between 1950 and 2000, the total population of West Africa increased fourfold, with almost one third now living in urban centres. (fao.org)
  • So far, the demographic processes - modern human population sizes, distributions and movements - that occurred within Africa during this critical period have been consistently under-addressed. (springer.com)
  • For anyone interested in African prehistory, populations, and paleoenvironments/ paleoclimates, Africa from MIS 6-2: Population Dynamics and Paleoenvironments is a must read. (springer.com)
  • Furthermore, although accelerated urbanization in sub-Saharan Africa is real (nearly 56% of its population will live in urban areas by 2050), this fact must not make us forget that Africa will probably see its rural population increase by 980 million people (by 2050), a figure representing one third of the world's rural population . (ideas4development.org)
  • Under these circumstances, the rate of growth of the population is constant and equal to the intrinsic rate of increase r . (encyclopedia.com)
  • What happens to population size over time under exponential growth ? (encyclopedia.com)
  • Exponential growth is also known as "J-shaped growth" because the shape of the curve of population size over time resembles the letter "J." Also, because the rate of growth of the population is constant, and does not depend on population density, exponential growth is also called "density-independent growth. (encyclopedia.com)
  • Analysis of the factors affecting human population growth and distribution, migration patterns, and the relationship between economic activity and population trends. (uvm.edu)
  • Batschelet E, Domingo E, Weissmann C (1976) The proportion of revertant and mutant phage in a growing population, as a function of mutation and growth rate. (springer.com)
  • Population dynamics focusses on the study of demographics, such as growth and decline, and the environmental processes that driving them. (wur.nl)
  • This paper focuses on two major elements of China's population dynamics-the rising proportion of workers in the population and the shift of rural workers from agriculture into industry and services-in a provincial-level analysis of per capita income and productivity growth during the last three decades. (repec.org)
  • We measure the 'mechanical' contributions of these dynamics to per capita income as revealed by growth decompositions, before assessing the determinants of per capita income and productivity growth in a series of regressions that include the growth of the working-age to total population (WAP) ratio and a measure of sectoral employment change. (repec.org)
  • However, the negative impact of sectoral change on productivity growth in the industrial and service sectors, combined with the negative impact of growth of the WAP ratio on both per capita income and aggregate productivity growth, suggests that the benefits of China's population dynamics during the last three decades have been overstated. (repec.org)
  • Population dynamics and economic growth in China ," China Economic Review , Elsevier, vol. 35(C), pages 15-32. (repec.org)
  • This research develops a continuous-time optimal growth model that accounts for population dynamics resembling the historical pattern of the demographic transition. (aimsciences.org)
  • During the mild winters of most of the 1980s, annual survival of caribou cows was high (~96% per year) and about 50% of calves were "recruited" into the population each fall, resulting in ~7% annual growth (see graph at right). (nps.gov)
  • The third and last paper I hope to write on (to end up as a chapter) in the civic education textbook is: The Dynamics and Linkages between Population Growth, Health and Environment. (cyburbia.org)
  • If environmental factors - macro and micro - change the preconditions for healthy life population growth will be affected. (cyburbia.org)
  • Kin increase and inequality is decreased with population growth and vice versa. (pnas.org)
  • The beginning of population dynamics is widely regarded as the work of Malthus, formulated as the Malthusian growth model. (wikipedia.org)
  • Thus r is the maximum theoretical rate of increase of a population per individual - that is, the maximum population growth rate. (wikipedia.org)
  • See also exponential population growth and logistic population growth. (wikipedia.org)
  • In effect this means that a growth of one population, needs to be balanced by comparable reduction in populations of others. (osti.gov)
  • We used radiotelemetry data collected on grouse to parameterize 6 models of population growth to: (1) determine the pattern of growth in these populations, and (2) identify the demographic rates most important to growth. (usda.gov)
  • Reproductive events improved estimates on areas dominated by mixed mesophytic forest, while survival events characterized population growth on oak (Quercus spp. (usda.gov)
  • At baseline values, survival of adults and juveniles may be the main determinants of growth in these populations, and reproduction may not be adequate to compensate for these losses. (usda.gov)
  • Evidence suggests that efforts to limit urban population growth, for example by restricting internal migration, have had limited success, if any. (unfpa.org)
  • In general, population growth roughly follows one of these trends: Logistic growth leveling out at some carrying capacity. (wikipedia.org)
  • The year 2007 marked a new milestone for human population growth: for the first time, more people worldwide were living in cities than in rural areas ( footnote 16 ). (learner.org)
  • Governments can make cities more efficient and livable by investing in public transportation systems and clean energy sources, and by planning ahead for growth so that they are able to provide basic services when populations expand. (learner.org)
  • The scale of urban poverty, already a pressing issue in many developing countries, may become even worse, as most population growth in the 21st century will happen in cities. (learner.org)
  • Many people (including national leaders) worry that population growth depletes resources and can trigger social or economic catastrophe if it is not contained. (learner.org)
  • As discussed in the preceding section, most of the projected population growth during this century will take place in developing nations. (learner.org)
  • Especially in the poorest countries, therefore, future population growth is likely to make environmental deterioration worse (although it does not automatically follow that countries with low population growth rates will have cleaner environments). (learner.org)
  • Rising population growth rates in the 1950s spurred worries that developing countries could deplete their food supplies. (learner.org)
  • The pattern of any process, or the interrelationship of phenomena, which affects growth or change within a population. (jove.com)
  • A new theoretical framework connects the exponential growth of a cell population to the stochastic replication of individual cells within the population. (aps.org)
  • They then derived and solved a set of equations that relate parameters of a whole cell population-like the rate of population growth-to the temporal distribution of the division times of individual cells. (aps.org)
  • They also showed that the model could extract, from a simple measurement of the population growth rate, cell-specific information, such as the mean growth rate of individual cells and the distributions of cell ages and of times between cell divisions. (aps.org)
  • Population Dynamics Worksheet and Teacher Printouts Best Worksheet for Kids Age 5 8 Teacher While there are many factors that will influence the future growth of your town or city, the number one factor is how many people move into your town or city. (ireggae.com)
  • Using this simulation, students investigate exponential and logistic population growth models and factors that regulate population sizes. (ireggae.com)
  • The population has show exponential growth since the industrial revolution and all countries will eventually move through the demographic transition. (ireggae.com)
  • Some of the worksheets for this concept are 4 population dynamics, Population dynamics work answers, Population dynamics, Human population growth work answer key, Igcse geography 0460 unit population dynamics, Population dynamics predatorprey, Deer predation or starvation, Population community ecosystem â ¦ Population Dynamics Worksheet along with Instructive Themes. (ireggae.com)
  • If population growth and urban growth are related, the sustainability of tomorrow's cities will above all depend on urban planning and how cities are linked with the rural world. (ideas4development.org)
  • The links between population growth and urban growth have often been presented from two angles: first, the idea that urbanization is the result of population growth, and, second, that demographic transition is faster in countries where urbanization is heavier . (ideas4development.org)
  • On the scale of human history, the pace of global population growth has accelerated over the past century. (ideas4development.org)
  • As a consequence, in any population the fixation of mutations is accelerated when environmental conditions cause population bottlenecks. (springer.com)
  • In a nonrecombinant haploid system, as is our focus here, mutations on the parental background(s) allow the population to explore neighboring regions of sequence space and thereby climb a fitness peak. (genetics.org)
  • Fisher 2013 ), while ignoring the specific mutations that underlie these population-wide quantities. (genetics.org)
  • In this work, we use these earlier theoretical treatments as the basis for analyzing the evolutionary dynamics of individual mutations ( i.e. , their frequencies over time and their eventual fates). (genetics.org)
  • A. S. Ackleh , J. Cleveland and H. R. Thieme , Population dynamics under selection and mutation: Long-time behavior for differential equations in measure spaces, Journal of Differential Equations , 261 (2016), 1472-1505. (aimsciences.org)
  • Dynamics of genome rearrangement in bacterial populations. (nih.gov)
  • Our findings represent the first characterization of genome arrangement evolution in a bacterial population evolving outside laboratory conditions. (nih.gov)
  • Insight into the process of genomic rearrangement may further the understanding of pathogen population dynamics and selection on the architecture of circular bacterial chromosomes. (nih.gov)
  • Bacterial population dynamics in dairy waste during aerobic and anaerobic treatment and subsequent storage. (cdc.gov)
  • The objective of this study was to model a typical dairy waste stream, monitor the chemical and bacterial population dynamics that occur during aerobic or anaerobic treatment and subsequent storage in a simulated lagoon, and compare them to those of waste held without treatment in a simulated lagoon. (cdc.gov)
  • The bacterial population structure of waste before and after treatment was monitored using 16S rRNA gene sequence libraries. (cdc.gov)
  • Both treatments had unique effects on the bacterial population structure of waste. (cdc.gov)
  • Previous studies have extensively characterized the homogenous dynamics of large bacterial populations exposed to antibiotics, establishing the deterministic framework of pharmacodynamics. (aps.org)
  • Here, characterizing small bacterial populations, we demonstrate the stochastic nature of bacterial clearance using antibiotics. (aps.org)
  • Bacterial cheating drives the population dynamics of cooperative antibiotic resistance plasmids. (sigmaaldrich.com)
  • However, the factors that determine the fraction of resistant cells in the bacterial population remain unclear, indicating a fundamental gap in our understanding of how antibiotic resistance evolves. (sigmaaldrich.com)
  • Here, we experimentally track the spread of a plasmid that encodes a β-lactamase enzyme through the bacterial population. (sigmaaldrich.com)
  • Populations that were persistently dominant, transiently abundant or generally rare were found in several major bacterial groups, implying evolution has favoured a similar variety of life strategies within these groups. (diva-portal.org)
  • Population density measures the number of individuals per unit area, for example, the number of deer per square kilometer. (encyclopedia.com)
  • One way to measure population density is simply to count all the individuals. (encyclopedia.com)
  • Alternatively, good estimates of population density can often be obtained via the quadrat method. (encyclopedia.com)
  • It is also commonly used to measure the population density of plants. (encyclopedia.com)
  • The rate at which a population increases in size if there are no density-dependent forces regulating the population is known as the intrinsic rate of increase. (wikipedia.org)
  • Density-independent: Affect a population equally regardless of its density. (wikipedia.org)
  • Density-dependent: Affect a population more or less as the population is bigger. (wikipedia.org)
  • Research on the mechanisms of density dependent regulation in populations of southern fin whales. (oregonstate.edu)
  • When the stationary measures are absolutely continuous with a continuous density, we show the convergence of the dynamics to the unique equilibrium. (aimsciences.org)
  • Researchers have concentrated on factors that determine the distribution, extinction and density of Iolana iolas populations in relation to the habitat patches formed by an endemic plant of the Iberian Peninsular, and host to butterflies, the Colutea hispanica (leguminous plant). (innovations-report.com)
  • Is the Subject Area "Population density" applicable to this article? (plos.org)
  • We find that independent of the initial fraction of resistant cells, the population settles to an equilibrium fraction proportional to the antibiotic concentration divided by the cell density. (sigmaaldrich.com)
  • Despite the fundamental importance of the seasonal dynamics of stand density, surprisingly few studies are available for broadcast rice, and none were known for deepwater rice until field studies started in Bangladesh in 1977. (springer.com)
  • The emigration rates describe the numbers of individuals who migrate out of the population per unit time. (encyclopedia.com)
  • It will take you through the fascinating mathematics of creating mathematical models to describe the changes in populations of living creatures. (maths.org)
  • We begin by introducing our model and briefly summarizing earlier results that describe the dynamics of the population's fitness distribution. (genetics.org)
  • In this chapter, we describe models of open populations that are subject to change over time due to additions and subtractions. (usgs.gov)
  • Largely concerned with mathematical models used to describe time-varying populations and series of events, The Dynamics of Discrete Populations and Series of Events demonstrates how analytical tools are used to develop, simulate, and solve discrete stochastic models. (routledge.com)
  • The mathematical formula below can used to model geometric populations. (wikipedia.org)
  • Geometric populations grow in discreet reproductive periods between intervals of abstinence, as opposed to populations which grow without designated periods for reproduction. (wikipedia.org)
  • This assumption, typically associated with equilibrium dynamics at the local scale, has emphasized the effect of large-scale heterogeneity in nearshore environmental conditions on recruitment (i.e., supply-side theory) to explain the regional dynamics of marine populations ( 6 , 9 ). (pnas.org)
  • Since 1975, caribou have been radiocollared in Denali to study their population dynamics and movements. (nps.gov)
  • The models will be applied to research the movements and population connectivity of blue crabs in the Northern Gulf of Mexico. (tulane.edu)
  • Simplified population models usually start with four key variables (four demographic processes) including death, birth, immigration, and emigration. (wikipedia.org)
  • While the impact on the ecosystem is well documented, the underlying processes and mechanisms behind the population dynamics of sandeel are still vaguely understood. (dtu.dk)
  • In addition, distinguishing the different dynamic processes may also become possible in the presence of auxiliary data on some demographic rates, in the context of integrated population models (IPMs, Besbeas et al. (usgs.gov)
  • It provides an understanding of the effect of the competing processes governing the changing number of individuals present in a population, and shows how relatively simple models can be used to generate a wide range of behaviours. (routledge.com)
  • Markovian Population Processes. (routledge.com)
  • P. Jagers and F. Klebaner , Population-size-dependent and age-dependent branching processes, Stochastic Processes and their Applications , 87 (2000), 235-254. (aimsciences.org)
  • M. G. Krein and M. A. Rutman , Population-size-dependent and age-dependent branching processes, Uspekhi Matematicheskikh Nauk , 3 (1948), 3-95. (aimsciences.org)
  • will focus on filling this gap by using mitochondrial and microsatellite DNA to infer population structure and by using satellite telemetry to infer movement patterns. (wur.nl)
  • To do so, we study the forward-time dynamics of specific mutant lineages on the backdrop of the population's fitness distribution, concentrating specifically on quantities relevant and measurable in experiments: the trajectories and sojourn times of polymorphic sites, fixation times of successful mutants, and some basic patterns of genetic diversity. (genetics.org)
  • Population dynamics has traditionally been the dominant branch of mathematical biology, which has a history of more than 220 years, although over the last century the scope of mathematical biology has greatly expanded. (wikipedia.org)
  • THE question of how populations adapt to changes in their environment has long been a central one in evolutionary biology. (genetics.org)
  • This chapter 6 biology the dynamics of life worksheet answers, as one of the most full of zip sellers here will very be along with the best options to review. (ireggae.com)
  • Therefore, we examined pre-service biology teachers' (n = 26) conceptions about ecosystem dynamics by asking them to draw and explain line graphs to predict the development of a population. (hu-berlin.de)
  • There are many potential explanations for oscillatory population dynamics (in the general sense), with some focusing on intrinsic factors, but most often invoking some aspect of consumer-resource interactions (we briefly review some theoretical and empirical mechanisms by which population cycles can arise in Section 11). (ucsb.edu)
  • establish correspondences between theoretical mechanisms that could drive cycles and quantitative descriptors of oscillatory population dynamics (these will be defined in Section 111. (ucsb.edu)
  • Now, Srividya Iyer-Biswas, of Purdue University in West Lafayette, Indiana, and colleagues have developed and tested a theoretical framework that could allow researchers to learn about the behavior of individual cells by studying the cell population at large. (aps.org)
  • The stochastic dynamics leading to the observed scale-invariant distributions has been studied as a Yule process, as a branching phenomenon and also by field-theoretical renormalization group techniques. (mdpi.com)
  • If r is negative, the population declines quickly to extinction. (encyclopedia.com)
  • But despite the fact that, as expected, postextinction single-neuron responses did not resemble "naive responses," ensemble response dynamics changed with learning and reverted with extinction: both the speed of stimulus processing and the relationships among ensemble responses to the different stimuli tracked behavioral relevance. (jneurosci.org)
  • As a result, the smallest habitat patches had lower butterfly population sizes and higher rates of extinction, irrespective of their quality of habitat. (innovations-report.com)
  • However, during the multiplication process of bacteria, there are high degrees of individuality or phenotypic heterogeneity in populations of genetically identical cells [ 2 - 5 ]. (hindawi.com)
  • Starting from first principles, the authors crafted a model for population behavior in which the cells have "memory," which is needed because a cell's history affects its aging process. (aps.org)
  • These data suggest that population coding is linked to behavior with a fidelity that single-neuron coding is not. (jneurosci.org)
  • We conclude that, despite the fact that single-neuron responses change with each new experience, ensemble response dynamics continue to accurately and stably reflect a sensory stimulus' relationship to behavior. (jneurosci.org)
  • Most work on the demography of kinship has concentrated on the nuclear family, lineal consanguineals, and household structure and has been informed by stable population theory. (pnas.org)
  • The Effects of Mortality on Fertility: Population Dynamics After a Natural Disaster, " Demography, vol 52(1), pages 15-38. (nber.org)
  • Convened in partnership with the Center for International Earth Science Information Network (CIESIN) at Columbia University, the CUNY Institute for Demographic Research (CIDR), and the UN Population Division, this seminar series will feature key experts from the fields of demography, climate and public health sharing insights on their interdisciplinary work to measure and solve climate related challenges. (popcouncil.org)
  • On the timescales comparable to the population doubling time, the regulation in the LHC structure occurs at the epigenetic level 4 and is considered as an acclimation. (nature.com)
  • These findings suggest that high temporal resolution sampling allows constraining the timescales and frequencies at which distinct populations transition between being abundant or rare, thus potentially providing clues about physical, chemical or biological forcing on bacterioplankton community structure. (diva-portal.org)
  • These policies also favor the migration of a large portion of the population (up to 100,000 people) to the Greater Male' Area. (prb.org)
  • Even the Sahara, which is often thought to be unpopulated, is in reality more and more urban: cities with populations of over 100,000 inhabitants are increasing in number there. (ideas4development.org)
  • The small bottleneck lines appeared to operate near the transition between isolated selective sweeps and conditions of complex dynamics ( e.g ., clonal interference). (genetics.org)
  • The algebraic symbols b, d and r stand for the rates of birth, death, and the rate of change per individual in the general population, the intrinsic rate of increase. (wikipedia.org)
  • It is d N d t 1 N = r {\displaystyle {\dfrac {dN}{dt}}{\dfrac {1}{N}}=r} where the derivative d N / d t {\displaystyle dN/dt} is the rate of increase of the population, N is the population size, and r is the intrinsic rate of increase. (wikipedia.org)
  • We study the long-time behaviour of a population structured by age and a phenotypic trait under a selection-mutation dynamics. (aimsciences.org)
  • For anyone interested in the study, management, and conservation of populations, this book will prove to be a valuable resource. (powells.com)
  • Implications of these outcomes are that opportunities for political networking and consolidation by means of kinship are altered by demographic instabilities, as are the dynamics of kin selection. (pnas.org)
  • This is especially true when dealing with the protection of the sexual and reproductive health and rights of all people, a sensitive area, and one with enormous implications for population dynamics. (unfpa.org)
  • Further, the extent of caching of seasonally abundant foods, such as large concentrations of nesting birds, and the implications of caching on population dynamics are unknown for most animals (Vander Wall, 1990). (thefreelibrary.com)
  • A closer examination of this portrait in Southwest Asia (SwAsia) and the Fertile Crescent (FC), a region which has supplied persuasive evidence on early presence of the domestic dog, retrieved the same information, with implications for backbreeding with the local wolf population. (diva-portal.org)
  • The focus of the course will be how mathematical models can help us both predict the future behaviour of populations and understand their dynamics. (warwick.ac.uk)
  • Ole Henriksen, DTU Aqua, will defend his PhD thesis "The factors driving the spatiotemporal population dynamics of sandeel in the North Sea", Friday 12 June 2020 at 13.00 CEST. (dtu.dk)
  • A copy of the PhD thesis "The factors driving the spatiotemporal population dynamics of sandeel in the North Sea" may be obtained via e-mail. (dtu.dk)
  • Because the genealogical generations specifying kinship relations are not temporal cohorts and most plausible demographic changes in anthropological populations are period shocks, the effect of such shocks on kin counts are complex. (pnas.org)
  • The harp seal population is monitored through a combination of aerial surveys that determine how many pups are born in a year, and the collection of seals by hunters to obtain information on age at maturity and age specific reproductive rates. (gc.ca)
  • This is done by calculating how many adults in a population would be required to produce the number of pups that are counted during the surveys, given the reproductive rates that are obtained from the sampling program. (gc.ca)
  • In addition to information on the number of pups born, and reproductive parameters, model inputs include removals from the population due to incidental catches by the fishing industry, the number of animals that are removed from the population by subsistence, and commercial harvesting, and also a factor that corrects removals by hunters for animals that may have been struck or killed but not recovered or reported. (gc.ca)
  • In addition to population and development policies, the Government had also adopted sectoral policies, including a Health Master Plan (a new one is being prepared), two youth strategies, several reproductive health policies, and a national gender strategy. (prb.org)
  • TLend estimates from population models were most similar to trend estimates derived from Breeding Bird Survey and Christmas Bird Count data when models incorporated either a reproductive or survival event. (usda.gov)
  • The International Conference on Population and Development , the Millennium Development Goals , and the upcoming post-2015 development agenda all call for unrestricted and universal access to sexual and reproductive health care, including voluntary family planning . (unfpa.org)
  • The basic reproductive rate R 0 {\displaystyle R_{0}} , also known as the replacement rate of a population, is the ratio of daughters to mothers. (wikipedia.org)
  • If there is immigration into the population, or emigration out of it, then the immigration rate and emigration rate are also of interest. (encyclopedia.com)
  • Emigration from the population may increase as it becomes more crowded. (wikipedia.org)
  • Conceptually, these models are described by the Birth-Immigration-Death-Emigration (BIDE) model of population dynamics (Conroy and Carroll, 2009). (usgs.gov)
  • An advanced mathematical exploration supporting our series of articles on population dynamics for advanced students. (maths.org)
  • Mathematical models used to calculate changes in population demographics and evolution hold the assumption ('null hypothesis') of no external influence. (wikipedia.org)
  • A. Calsina and J. M. Palmada , Steady states of a selection-mutation model for an age structured population, Journal of Mathematical Analysis and Applications , 400 (2013), 386-395. (aimsciences.org)
  • L. Desvillettes , P. E. Jabin , S. Mischler and G. Raoul , On selection dynamics for continuous structured populations, Communications in Mathematical Sciences , 6 (2008), 729-747. (aimsciences.org)
  • The first and most basic model of population dynamics assumes that an environment has unlimited resources and can support an unlimited number of individuals. (encyclopedia.com)
  • The integration of a fertility module and a base population allows the user to bring new actors into the simulation and transform a cohort-based model into a population-based one. (springer.com)
  • A population model is then used to determine total population size. (gc.ca)
  • The model achieves this by adjusting the mortality rate of the adults so that the modeled population produces the observed number of pups. (gc.ca)
  • In the next section, the proposed model is described and the global dynamics is obtained. (hindawi.com)
  • length-based model of population dynamics. (oregonstate.edu)
  • This model also successfully predicts that adding a commonly used β-lactamase inhibitor will lead to the spread of resistance, highlighting the need to incorporate social dynamics into the study of antibiotic resistance. (sigmaaldrich.com)
  • A System Dynamics Model for a Sustainable Fish Population. (igi-global.com)
  • Understanding how mortality and fertility are linked is essential to the study of population dynamics. (nber.org)
  • Seasonal dynamics in somatic condition, relative lipid content and gonad mass, and their comparison with other R. amarus populations, suggest that the study population allocated a disproportionally high level of resources to reproduction. (ingentaconnect.com)
  • Large bird colonies therefore provide an ideal setting to study food caching by arctic foxes and the link between seasonally abundant foods and population dynamics. (thefreelibrary.com)
  • In this study, which was part of Shannon Pellini's (Harvard Forest Postdoctoral fellow) dissertation work under the advisement of Jessica Hellmann at the University of Notre Dame, Shannon and colleagues performed field and laboratory reciprocal translocation experiments with skipper ( Erynnis propertius ) and swallowtail ( Papilio zelicaon ) butterfly populations from Oregon and Vancouver Island. (harvard.edu)
  • This fellowship provides a full year of stipend support and release from teaching so that Sydne can focus full-time on her disseration research on understory plants, ants, and ecosystem dynamics. (harvard.edu)
  • The Balance of Nature (BoN) metaphor leads to various naïve conceptions about ecosystem dynamics that do not address current scientific theories adequately. (hu-berlin.de)