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)

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)

Ecological and environmental entities, characteristics, properties, relationships and processes.

The variety of all native living organisms and their various forms and interrelationships.

The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.

The pattern of any process, or the interrelationship of phenomena, which affects growth or change within a population.

The relationships of groups of organisms as reflected by their genetic makeup.

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.

Ecosystem and environmental activities, functions, or events.

Warm-blooded VERTEBRATES possessing FEATHERS and belonging to the class Aves.

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)

The spectrum of different living organisms inhabiting a particular region, habitat, or biotope.

Behavioral responses or sequences associated with eating including modes of feeding, rhythmic patterns of eating, and time intervals.

The protection, preservation, restoration, and rational use of all resources in the total environment.

Number of individuals in a population relative to space.

Instinctual behavior pattern in which food is obtained by killing and consuming other species.

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.

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 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.

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)

Woody, usually tall, perennial higher plants (Angiosperms, Gymnosperms, and some Pterophyta) having usually a main stem and numerous branches.

The salinated water of OCEANS AND SEAS that provides habitat for marine organisms.

The external elements and conditions which surround, influence, and affect the life and development of an organism or population.

The study of the origin, structure, development, growth, function, genetics, and reproduction of organisms which inhabit the OCEANS AND SEAS.

Invertebrates or non-human vertebrates which transmit infective organisms from one host to another.

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).

A process by which animals in various forms and stages of development are physically distributed through time and space.

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.

A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.

Physiological processes and properties of BACTERIA.

The longterm manifestations of WEATHER. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)

The study of microorganisms living in a variety of environments (air, soil, water, etc.) and their pathogenic relationship to other organisms including man.

The total process by which organisms produce offspring. (Stedman, 25th ed)

Minute free-floating animal organisms which live in practically all natural waters.

A collective genome representative of the many organisms, primarily microorganisms, existing in a community.

A group of cold-blooded, aquatic vertebrates having gills, fins, a cartilaginous or bony endoskeleton, and elongated bodies covered with scales.

Animal behavior associated with the nest; includes construction, effects of size and material; behavior of the adult during the nesting period and the effect of the nest on the behavior of the young.

Remains, impressions, or traces of animals or plants of past geological times which have been preserved in the earth's crust.

Genotypic differences observed among individuals in a population.

Order of mammals whose members are adapted for flight. It includes bats, flying foxes, and fruit bats.

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.

The physical measurements of a body.

Large natural streams of FRESH WATER formed by converging tributaries and which empty into a body of water (lake or ocean).

Insects that transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.

A chain of islands, cays, and reefs in the West Indies, lying southeast of Florida and north of Cuba. It is an independent state, called also the Commonwealth of the Bahamas or the Bahama Islands. The name likely represents the local name Guanahani, itself of uncertain origin. (From Webster's New Geographical Dictionary, 1988, p106 & Room, Brewer's Dictionary of Names, 1992, p45)

Constituent of 30S subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16S rRNA is involved in initiation of polypeptide synthesis.

The presence of bacteria, viruses, and fungi in water. This term is not restricted to pathogenic organisms.

The contents included in all or any segment of the GASTROINTESTINAL TRACT.

The presence of bacteria, viruses, and fungi in the soil. This term is not restricted to pathogenic organisms.

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.

Community of tiny aquatic PLANTS and ANIMALS, and photosynthetic BACTERIA, that are either free-floating or suspended in the water, with little or no power of locomotion. They are divided into PHYTOPLANKTON and ZOOPLANKTON.

Water containing no significant amounts of salts, such as water from RIVERS and LAKES.

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.

Places for cultivation and harvesting of fish, particularly in sea waters. (from McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

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 physiological processes, properties, and states characteristic of plants.

A diverse genus of minute freshwater CRUSTACEA, of the suborder CLADOCERA. They are a major food source for both young and adult freshwater fish.

The ceasing of existence of a species or taxonomic groups of organisms.

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)

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.

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.

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)

The observable response an animal makes to any situation.

Non-native organisms brought into a region, habitat, or ECOSYSTEM by human activity.

A genus of the family Lemuridae consisting of five species: L. catta (ring-tailed lemur), L. fulvus, L. macaco (acoumba or black lemur), L. mongoz (mongoose lemur), and L. variegatus (white lemur). Most members of this genus occur in forested areas on Madagascar and the Comoro Islands.

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.

Organisms that live in water.

The consumption of animal flesh.

Changes in biological features that help an organism cope with its ENVIRONMENT. These changes include physiological (ADAPTATION, PHYSIOLOGICAL), phenotypic and genetic changes.

The genomic analysis of assemblages of organisms.

Marine, freshwater, or terrestrial mollusks of the class Gastropoda. Most have an enclosing spiral shell, and several genera harbor parasites pathogenic to man.

The comparative and theoretical study of culture, often synonymous with cultural anthropology.

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 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.

Members of the group of vascular plants which bear flowers. They are differentiated from GYMNOSPERMS by their production of seeds within a closed chamber (OVARY, PLANT). The Angiosperms division is composed of two classes, the monocotyledons (Liliopsida) and dicotyledons (Magnoliopsida). Angiosperms represent approximately 80% of all known living plants.

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.

An animal or plant species in danger of extinction. Causes can include human activity, changing climate, or change in predator/prey ratios.

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.

Tracts of land completely surrounded by water.

Animals that have no spinal column.

The study of early forms of life through fossil remains.

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.

The natural satellite of the planet Earth. It includes the lunar cycles or phases, the lunar month, lunar landscapes, geography, and soil.

Diseases of non-human animals that may be transmitted to HUMANS or may be transmitted from humans to non-human animals.

The splitting of an ancestral species into daughter species that coexist in time (King, Dictionary of Genetics, 6th ed). Causal factors may include geographic isolation, HABITAT geometry, migration, REPRODUCTIVE ISOLATION, random GENETIC DRIFT and MUTATION.

The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.

Insects of the family Formicidae, very common and widespread, probably the most successful of all the insect groups. All ants are social insects, and most colonies contain three castes, queens, males, and workers. Their habits are often very elaborate and a great many studies have been made of ant behavior. Ants produce a number of secretions that function in offense, defense, and communication. (From Borror, et al., An Introduction to the Study of Insects, 4th ed, p676)

Inland bodies of still or slowly moving FRESH WATER or salt water, larger than a pond, and supplied by RIVERS and streams.

Generally refers to the digestive structures stretching from the MOUTH to ANUS, but does not include the accessory glandular organs (LIVER; BILIARY TRACT; PANCREAS).

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.

One of the three domains of life (the others being BACTERIA and Eukarya), formerly called Archaebacteria under the taxon Bacteria, but now considered separate and distinct. They are characterized by: (1) the presence of characteristic tRNAs and ribosomal RNAs; (2) the absence of peptidoglycan cell walls; (3) the presence of ether-linked lipids built from branched-chain subunits; and (4) their occurrence in unusual habitats. While archaea resemble bacteria in morphology and genomic organization, they resemble eukarya in their method of genomic replication. The domain contains at least four kingdoms: CRENARCHAEOTA; EURYARCHAEOTA; NANOARCHAEOTA; and KORARCHAEOTA.

A widely distributed order of perching BIRDS, including more than half of all bird species.

Computer systems capable of assembling, storing, manipulating, and displaying geographically referenced information, i.e. data identified according to their locations.

Techniques used to determine the age of materials, based on the content and half-lives of the RADIOACTIVE ISOTOPES they contain.

Water particles that fall from the ATMOSPHERE.

A mammalian order which consists of 29 families and many genera.

Constituent of the 40S subunit of eukaryotic ribosomes. 18S rRNA is involved in the initiation of polypeptide synthesis in eukaryotes.

A discipline or occupation concerned with the study of INSECTS, including the biology and the control of insects.

Slender-bodies diurnal insects having large, broad wings often strikingly colored and patterned.

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.

One of the Indian Ocean Islands off the southeast coast of Africa. Its capital is Antananarivo. It was formerly called the Malagasy Republic. Discovered by the Portuguese in 1500, its history has been tied predominantly to the French, becoming a French protectorate in 1882, a French colony in 1896, and a territory within the French union in 1946. The Malagasy Republic was established in the French Community in 1958 but it achieved independence in 1960. Its name was changed to Madagascar in 1975. (From Webster's New Geographical Dictionary, 1988, p714)

Instinctual patterns of activity related to a specific area including ability of certain animals to return to a given place when displaced from it, often over great distances using navigational clues such as those used in migration (ANIMAL MIGRATION).

The flow of water in enviromental bodies of water such as rivers, oceans, water supplies, aquariums, etc. It includes currents, tides, and waves.

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 continent lying around the South Pole and the southern waters of the Atlantic, Pacific, and Indian Oceans. It includes the Falkland Islands Dependencies. (From Webster's New Geographical Dictionary, 1988, p55)

The transfer of POLLEN grains (male gametes) to the plant ovule (female gamete).

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 cat family in the order CARNIVORA comprised of muscular, deep-chested terrestrial carnivores with a highly predatory lifestyle.

Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.

Deoxyribonucleic acid that makes up the genetic material of bacteria.

In evolutionary theory, overlapping geographic distribution of diverging species. In sympatric GENETIC SPECIATION, genetic diversion occurs without geographic separation.

A subclass of cartilaginous fish comprising the SHARKS; rays; skates (SKATES (FISH);), and sawfish. Elasmobranchs are typically predaceous, relying more on smell (the olfactory capsules are relatively large) than sight (the eyes are relatively small) for obtaining their food.

The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.

Techniques for standardizing and expediting taxonomic identification or classification of organisms that are based on deciphering the sequence of one or a few regions of DNA known as the "DNA barcode".

A plant genus of the family FABACEAE. The gums and tanning agents obtained from Acacia are called GUM ARABIC. The common name of catechu is more often used for Areca catechu (ARECA).

Stable nitrogen atoms that have the same atomic number as the element nitrogen, but differ in atomic weight. N-15 is a stable nitrogen isotope.

The act of feeding on plants by animals.

Medium-sized terrestrial carnivores, in the genus Canis, family CANIDAE. Three species are recognized, two found only in Africa and one found in Africa, Europe, and Asia.

Diseases of birds not considered poultry, therefore usually found in zoos, parks, and the wild. The concept is differentiated from POULTRY DISEASES which is for birds raised as a source of meat or eggs for human consumption, and usually found in barnyards, hatcheries, etc.

A group of elongate elasmobranchs. Sharks are mostly marine fish, with certain species large and voracious.

The systematic surveying, mapping, charting, and description of specific geographical sites, with reference to the physical features that were presumed to influence health and disease. Medical topography should be differentiated from EPIDEMIOLOGY in that the former emphasizes geography whereas the latter emphasizes disease outbreaks.

The study of aquatic life inhabiting bodies of water, including growth, morphology, physiology, genetics, distribution, and interactions with other organisms and the environment. It includes MARINE HYDROBIOLOGY.

A French overseas department on the northeast coast of South America. Its capital is Cayenne. It was first settled by the French in 1604. Early development was hindered because of the presence of a penal colony. The name of the country and the capital are variants of Guyana, possibly from the native Indian Guarani guai (born) + ana (kin), implying a united and interrelated race of people. (From Webster's New Geographical Dictionary, 1988, p418 & Room, Brewer's Dictionary of Names, 1992, p195)

DNA sequences encoding RIBOSOMAL RNA and the segments of DNA separating the individual ribosomal RNA genes, referred to as RIBOSOMAL SPACER DNA.

Statistical interpretation and description of a population with reference to distribution, composition, or structure.

Differential and non-random reproduction of different genotypes, operating to alter the gene frequencies within a population.

Increase, over a specific period of time, in the number of individuals living in a country or region.

Communications using an active or passive satellite to extend the range of radio, television, or other electronic transmission by returning signals to earth from an orbiting satellite.

Physiological processes and properties of microorganisms, including ARCHAEA; BACTERIA; RICKETTSIA; VIRUSES; FUNGI; and others.

Any of numerous winged hymenopterous insects of social as well as solitary habits and having formidable stings.

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)

A genus of mosquitoes (CULICIDAE) that are known vectors of MALARIA.

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.

A genus of marine planktonic CYANOBACTERIA in the order PROCHLOROPHYTES. They lack PHYCOBILISOMES and contain divinyl CHLOROPHYLL, a and b.

The genus Lepus, in the family Leporidae, order LAGOMORPHA. Hares are born above ground, fully furred, and with their eyes and ears open. In contrast with RABBITS, hares have 24 chromosome pairs.

A mass of organic or inorganic solid fragmented material, or the solid fragment itself, that comes from the weathering of rock and is carried by, suspended in, or dropped by air, water, or ice. It refers also to a mass that is accumulated by any other natural agent and that forms in layers on the earth's surface, such as sand, gravel, silt, mud, fill, or loess. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1689)

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.

An order of fish including the families Gadidae (cods), Macrouridae (grenadiers), and hakes. The large Gadidae family includes cod, haddock, whiting, and pollock.

An order of MAMMALS, usually flesh eaters with appropriate dentition. Suborders include the terrestrial carnivores Fissipedia, and the aquatic carnivores PINNIPEDIA.

A class in the phylum MOLLUSCA comprised of mussels; clams; OYSTERS; COCKLES; and SCALLOPS. They are characterized by a bilaterally symmetrical hinged shell and a muscular foot used for burrowing and anchoring.

Members of the phylum Arthropoda, composed of organisms having a hard, jointed exoskeleton and paired jointed legs. It includes the class INSECTS and the subclass ARACHNIDA, many species of which are important medically as parasites or as vectors of organisms capable of causing disease in man.

Invertebrate organisms that live on or in another organism (the host), and benefit at the expense of the other. Traditionally excluded from definition of parasites are pathogenic BACTERIA; FUNGI; VIRUSES; and PLANTS; though they may live parasitically.

Large, robust forms of brown algae (PHAEOPHYCEAE) in the order Laminariales. They are a major component of the lower intertidal and sublittoral zones on rocky coasts in temperate and polar waters. Kelp, a kind of SEAWEED, usually refers to species in the genera LAMINARIA or MACROCYSTIS, but the term may also be used for species in FUCUS or Nereocystis.

A phylum of small sessile aquatic animals living as small tufted colonies. Some appear like hydroids or corals, but their internal structure is more advanced. Most bryozoans are matlike, forming thin encrustations on rocks, shells, or kelp. (Storer & Stebbins, General Zoology, 6th ed, p443)

Physiological functions characteristic of plants.

The inanimate matter of Earth, the structures and properties of this matter, and the processes that affect it.

A plant family of the order Orchidales, subclass Liliidae, class Liliopsida (monocotyledons). All orchids have the same bilaterally symmetrical flower structure, with three sepals, but the flowers vary greatly in color and shape.

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 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)

Environments or habitats at the interface between truly terrestrial ecosystems and truly aquatic systems making them different from each yet highly dependent on both. Adaptations to low soil oxygen characterize many wetland species.

The full collection of microbes (bacteria, fungi, virus, etc.) that naturally exist within a particular biological niche such as an organism, soil, a body of water, etc.

The geographical area of Africa comprising ANGOLA; BOTSWANA; LESOTHO; MALAWI; MOZAMBIQUE; NAMIBIA; SOUTH AFRICA; SWAZILAND; ZAMBIA; and ZIMBABWE.

The science, art or practice of cultivating soil, producing crops, and raising livestock.

A plant genus of the family FAGACEAE that is a source of TANNINS. Do not confuse with Holly (ILEX).

Biological action and events that support the functions of the EYE and VISION, OCULAR.

The sole family in the order Sphenisciformes, comprised of 17 species of penguins in six genera. They are flightless seabirds of the Southern Hemisphere, highly adapted for marine life.

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.

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.

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.

General name for two extinct orders of reptiles from the Mesozoic era: Saurischia and Ornithischia.

Infection of domestic and wild fowl and other BIRDS with INFLUENZA A VIRUS. Avian influenza usually does not sicken birds, but can be highly pathogenic and fatal in domestic POULTRY.

Communication between animals involving the giving off by one individual of some chemical or physical signal, that, on being received by another, influences its behavior.

The family Hirundinidae, comprised of small BIRDS that hunt flying INSECTS while in sustained flight.

Activities performed by humans.

Eating of excrement by animal species.

Sexual activities of animals.

Large herbivorous tropical American lizards.

Any behavior caused by or affecting another individual, usually of the same species.

The reproductive organs of plants.

Infectious diseases that are novel in their outbreak ranges (geographic and host) or transmission mode.

Constituent of the 60S subunit of eukaryotic ribosomes. 28S rRNA is involved in the initiation of polypeptide synthesis in eukaryotes.

A plant genus of subsucculent annual or perennial plants in the family BALSAMINACEAE, order Geraniales.

A kingdom of eukaryotic, heterotrophic organisms that live parasitically as saprobes, including MUSHROOMS; YEASTS; smuts, molds, etc. They reproduce either sexually or asexually, and have life cycles that range from simple to complex. Filamentous fungi, commonly known as molds, refer to those that grow as multicellular colonies.

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.

An order of CRENARCHAEOTA comprised of irregular coccoid to disc-shaped, hyperthermophiles, and found in submarine hydrothermal systems and solfataric hot springs.

The systematic arrangement of entities in any field into categories classes based on common characteristics such as properties, morphology, subject matter, etc.

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.

Care of a highly technical and specialized nature, provided in a medical center, usually one affiliated with a university, for patients with unusually severe, complex, or uncommon health problems.

A genus in the family FELIDAE comprising felines with long legs, ear tufts, and a short tail.

The direct struggle between individuals for environmental necessities or for a common goal.

A family of terrestrial carnivores with long, slender bodies, long tails, and anal scent glands. They include badgers, weasels, martens, FERRETS; MINKS; wolverines, polecats, and OTTERS.

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.

Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.

A nonmetallic element with atomic symbol C, atomic number 6, and atomic weight [12.0096; 12.0116]. It may occur as several different allotropes including DIAMOND; CHARCOAL; and GRAPHITE; and as SOOT from incompletely burned fuel.

Degree of saltiness, which is largely the OSMOLAR CONCENTRATION of SODIUM CHLORIDE plus any other SALTS present. It is an ecological factor of considerable importance, influencing the types of organisms that live in an ENVIRONMENT.

An order of amoeboid EUKARYOTES characterized by reticulating pseudopods and a complex life cycle with an alternation of generations. Most are less than 1mm in size and found in marine or brackish water.

The motion of air relative to the earth's surface.

The comparative study of animal structure with regard to homologous organs or parts. (Stedman, 25th ed)

Transmission of the readings of instruments to a remote location by means of wires, radio waves, or other means. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)