Extinction, Psychological: The procedure of presenting the conditioned stimulus without REINFORCEMENT to an organism previously conditioned. It refers also to the diminution of a conditioned response resulting from this procedure.Extinction, Biological: The ceasing of existence of a species or taxonomic groups of organisms.Fear: The affective response to an actual current external danger which subsides with the elimination of the threatening condition.Conditioning, Classical: Learning that takes place when a conditioned stimulus is paired with an unconditioned stimulus.Freezing Reaction, Cataleptic: An induced response to threatening stimuli characterized by the cessation of body movements, except for those that are involved with BREATHING, and the maintenance of an immobile POSTURE.Conditioning (Psychology): A general term referring to the learning of some particular response.Cycloserine: Antibiotic substance produced by Streptomyces garyphalus.Fossils: Remains, impressions, or traces of animals or plants of past geological times which have been preserved in the earth's crust.Conditioning, Operant: Learning situations in which the sequence responses of the subject are instrumental in producing reinforcement. When the correct response occurs, which involves the selection from among a repertoire of responses, the subject is immediately reinforced.Models, Biological: 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.Paleontology: The study of early forms of life through fossil remains.Amygdala: Almond-shaped group of basal nuclei anterior to the INFERIOR HORN OF THE LATERAL VENTRICLE of the TEMPORAL LOBE. The amygdala is part of the limbic system.Population Dynamics: The pattern of any process, or the interrelationship of phenomena, which affects growth or change within a population.Electroshock: Induction of a stress reaction in experimental subjects by means of an electrical shock; applies to either convulsive or non-convulsive states.Conservation of Natural Resources: The protection, preservation, restoration, and rational use of all resources in the total environment.Association Learning: The principle that items experienced together enter into a connection, so that one tends to reinstate the other.Ecosystem: 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)Biodiversity: The variety of all native living organisms and their various forms and interrelationships.Biological Evolution: The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.Reinforcement (Psychology): The strengthening of a conditioned response.Self Administration: Administration of a drug or chemical by the individual under the direction of a physician. It includes administration clinically or experimentally, by human or animal.Avoidance Learning: A response to a cue that is instrumental in avoiding a noxious experience.Behavior, Animal: The observable response an animal makes to any situation.Drug-Seeking Behavior: Activities performed to obtain licit or illicit substances.Galvanic Skin Response: A change in electrical resistance of the skin, occurring in emotion and in certain other conditions.Cues: Signals for an action; that specific portion of a perceptual field or pattern of stimuli to which a subject has learned to respond.Memory: Complex mental function having four distinct phases: (1) memorizing or learning, (2) retention, (3) recall, and (4) recognition. Clinically, it is usually subdivided into immediate, recent, and remote memory.Endangered Species: An animal or plant species in danger of extinction. Causes can include human activity, changing climate, or change in predator/prey ratios.Reinforcement Schedule: A schedule prescribing when the subject is to be reinforced or rewarded in terms of temporal interval in psychological experiments. The schedule may be continuous or intermittent.Cocaine: An alkaloid ester extracted from the leaves of plants including coca. It is a local anesthetic and vasoconstrictor and is clinically used for that purpose, particularly in the eye, ear, nose, and throat. It also has powerful central nervous system effects similar to the amphetamines and is a drug of abuse. Cocaine, like amphetamines, acts by multiple mechanisms on brain catecholaminergic neurons; the mechanism of its reinforcing effects is thought to involve inhibition of dopamine uptake.Prefrontal Cortex: The rostral part of the frontal lobe, bounded by the inferior precentral fissure in humans, which receives projection fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from numerous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical afferents of visual, auditory, and somatic origin.Time Factors: Elements of limited time intervals, contributing to particular results or situations.History, Ancient: The period of history before 500 of the common era.Appetitive Behavior: Animal searching behavior. The variable introductory phase of an instinctive behavior pattern or sequence, e.g., looking for food, or sequential courtship patterns prior to mating.Population Density: Number of individuals in a population relative to space.Rats, Long-Evans: An outbred strain of rats developed in 1915 by crossing several Wistar Institute white females with a wild gray male. Inbred strains have been derived from this original outbred strain, including Long-Evans cinnamon rats (RATS, INBRED LEC) and Otsuka-Long-Evans-Tokushima Fatty rats (RATS, INBRED OLETF), which are models for Wilson's disease and non-insulin dependent diabetes mellitus, respectively.Geography: 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)Behavior, Addictive: The observable, measurable, and often pathological activity of an organism that portrays its inability to overcome a habit resulting in an insatiable craving for a substance or for performing certain acts. The addictive behavior includes the emotional and physical overdependence on the object of habit in increasing amount or frequency.Birds: Warm-blooded VERTEBRATES possessing FEATHERS and belonging to the class Aves.Biological Products: Complex pharmaceutical substances, preparations, or matter derived from organisms usually obtained by biological methods or assay.Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Startle Reaction: A complex involuntary response to an unexpected strong stimulus usually auditory in nature.Analysis of Variance: A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Marine Biology: The study of the origin, structure, development, growth, function, genetics, and reproduction of organisms which inhabit the OCEANS AND SEAS.Human Activities: Activities performed by humans.Ecology: 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)Environment: The external elements and conditions which surround, influence, and affect the life and development of an organism or population.Species Specificity: 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.Mammals: Warm-blooded vertebrate animals belonging to the class Mammalia, including all that possess hair and suckle their young.Retention (Psychology): The persistence to perform a learned behavior (facts or experiences) after an interval has elapsed in which there has been no performance or practice of the behavior.Dopamine Uptake Inhibitors: Drugs that block the transport of DOPAMINE into axon terminals or into storage vesicles within terminals. Most of the ADRENERGIC UPTAKE INHIBITORS also inhibit dopamine uptake.Volcanic Eruptions: The ash, dust, gases, and lava released by volcanic explosion. The gases are volatile matter composed principally of about 90% water vapor, and carbon dioxide, sulfur dioxide, hydrogen, carbon monoxide, and nitrogen. The ash or dust is pyroclastic ejecta and lava is molten extrusive material consisting mainly of magnesium silicate. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Biological Assay: A method of measuring the effects of a biologically active substance using an intermediate in vivo or in vitro tissue or cell model under controlled conditions. It includes virulence studies in animal fetuses in utero, mouse convulsion bioassay of insulin, quantitation of tumor-initiator systems in mouse skin, calculation of potentiating effects of a hormonal factor in an isolated strip of contracting stomach muscle, etc.Mental Recall: The process whereby a representation of past experience is elicited.Biological Therapy: Treatment of diseases with biological materials or biological response modifiers, such as the use of GENES; CELLS; TISSUES; organs; SERUM; VACCINES; and humoral agents.Acoustic Stimulation: Use of sound to elicit a response in the nervous system.Amphibians: VERTEBRATES belonging to the class amphibia such as frogs, toads, newts and salamanders that live in a semiaquatic environment.Molecular Sequence Data: 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.Geology: The science of the earth and other celestial bodies and their history as recorded in the rocks. It includes the study of geologic processes of an area such as rock formations, weathering and erosion, and sedimentation. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Cocaine-Related Disorders: Disorders related or resulting from use of cocaine.Geological Phenomena: The inanimate matter of Earth, the structures and properties of this matter, and the processes that affect it.Food Chain: 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.Antimetabolites: Drugs that are chemically similar to naturally occurring metabolites, but differ enough to interfere with normal metabolic pathways. (From AMA Drug Evaluations Annual, 1994, p2033)Climate Change: 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.Learning: Relatively permanent change in behavior that is the result of past experience or practice. The concept includes the acquisition of knowledge.Chytridiomycota: A phylum of fungi that was formerly considered a subdivision of Phycomycetes. They are the only fungi that produce motile spores (zoospores) at some stage in their life cycle. Most are saprobes but they also include examples of plant, animal, and fungal pathogens.Columbidae: Family in the order COLUMBIFORMES, comprised of pigeons or doves. They are BIRDS with short legs, stout bodies, small heads, and slender bills. Some sources call the smaller species doves and the larger pigeons, but the names are interchangeable.Cephalopoda: A class in the phylum MOLLUSCA comprised of SQUID; CUTTLEFISH; OCTOPUS; and NAUTILUS. These marine animals are the most highly organized of all the mollusks.Computer Simulation: Computer-based representation of physical systems and phenomena such as chemical processes.Carnivora: An order of MAMMALS, usually flesh eaters with appropriate dentition. Suborders include the terrestrial carnivores Fissipedia, and the aquatic carnivores PINNIPEDIA.Radiometric Dating: Techniques used to determine the age of materials, based on the content and half-lives of the RADIOACTIVE ISOTOPES they contain.Invertebrates: Animals that have no spinal column.Muscimol: A neurotoxic isoxazole isolated from species of AMANITA. It is obtained by decarboxylation of IBOTENIC ACID. Muscimol is a potent agonist of GABA-A RECEPTORS and is used mainly as an experimental tool in animal and tissue studies.Discrimination Learning: Learning that is manifested in the ability to respond differentially to various stimuli.Limbic System: A set of forebrain structures common to all mammals that is defined functionally and anatomically. It is implicated in the higher integration of visceral, olfactory, and somatic information as well as homeostatic responses including fundamental survival behaviors (feeding, mating, emotion). For most authors, it includes the AMYGDALA; EPITHALAMUS; GYRUS CINGULI; hippocampal formation (see HIPPOCAMPUS); HYPOTHALAMUS; PARAHIPPOCAMPAL GYRUS; SEPTAL NUCLEI; anterior nuclear group of thalamus, and portions of the basal ganglia. (Parent, Carpenter's Human Neuroanatomy, 9th ed, p744; NeuroNames, http://rprcsgi.rprc.washington.edu/neuronames/index.html (September 2, 1998)).Biological Warfare: Warfare involving the use of living organisms or their products as disease etiologic agents against people, animals, or plants.Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.Reptiles: Cold-blooded, air-breathing VERTEBRATES belonging to the class Reptilia, usually covered with external scales or bony plates.Stochastic Processes: Processes that incorporate some element of randomness, used particularly to refer to a time series of random variables.Climate: The longterm manifestations of WEATHER. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Biological Markers: Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.Self-Injurious Behavior: Behavior in which persons hurt or harm themselves without the motive of suicide or of sexual deviation.Implosive Therapy: A method for extinguishing anxiety by a saturation exposure to the feared stimulus situation or its substitute.Genetic Speciation: 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.Escape Reaction: Innate response elicited by sensory stimuli associated with a threatening situation, or actual confrontation with an enemy.Models, Theoretical: 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.Foraminifera: 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.Reward: An object or a situation that can serve to reinforce a response, to satisfy a motive, or to afford pleasure.Biological Processes: Biological activities and function of the whole organism in human, animal, microorgansims, and plants, and of the biosphere.Plants: 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.Anisomycin: An antibiotic isolated from various Streptomyces species. It interferes with protein and DNA synthesis by inhibiting peptidyl transferase or the 80S ribosome system.Predatory Behavior: Instinctual behavior pattern in which food is obtained by killing and consuming other species.Trees: Woody, usually tall, perennial higher plants (Angiosperms, Gymnosperms, and some Pterophyta) having usually a main stem and numerous branches.Models, Genetic: 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.Computational Biology: A field of biology concerned with the development of techniques for the collection and manipulation of biological data, and the use of such data to make biological discoveries or predictions. This field encompasses all computational methods and theories for solving biological problems including manipulation of models and datasets.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Oxepins: Compounds based on a 7-membered heterocyclic ring including an oxygen. They can be considered a medium ring ether. A natural source is the MONTANOA plant genus. Some dibenzo-dioxepins, called depsidones, are found in GARCINIA plants.Vertebrates: Animals having a vertebral column, members of the phylum Chordata, subphylum Craniata comprising mammals, birds, reptiles, amphibians, and fishes.PhenoxyacetatesOceans and Seas: 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).Mediodorsal Thalamic Nucleus: The largest of the medial nuclei of the thalamus. It makes extensive connections with most of the other thalamic nuclei.Nucleus Accumbens: Collection of pleomorphic cells in the caudal part of the anterior horn of the LATERAL VENTRICLE, in the region of the OLFACTORY TUBERCLE, lying between the head of the CAUDATE NUCLEUS and the ANTERIOR PERFORATED SUBSTANCE. It is part of the so-called VENTRAL STRIATUM, a composite structure considered part of the BASAL GANGLIA.Time: The dimension of the physical universe which, at a given place, orders the sequence of events. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Feeding and Eating Disorders of Childhood: Mental disorders related to feeding and eating usually diagnosed in infancy or early childhood.Archaeology: The scientific study of past societies through artifacts, fossils, etc.Generalization, Stimulus: The tendency to react to stimuli that are different from, but somewhat similar to, the stimulus used as a conditioned stimulus.Heroin: A narcotic analgesic that may be habit-forming. It is a controlled substance (opium derivative) listed in the U.S. Code of Federal Regulations, Title 21 Parts 329.1, 1308.11 (1987). Sale is forbidden in the United States by Federal statute. (Merck Index, 11th ed)Perceptual Disorders: Cognitive disorders characterized by an impaired ability to perceive the nature of objects or concepts through use of the sense organs. These include spatial neglect syndromes, where an individual does not attend to visual, auditory, or sensory stimuli presented from one side of the body.Body Size: The physical measurements of a body.Behavior Therapy: The application of modern theories of learning and conditioning in the treatment of behavior disorders.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Genetic Variation: Genotypic differences observed among individuals in a population.Gene Expression Profiling: The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.Mammoths: An extinct genus of large mammals in the family Elephantidae that fed by grazing on low vegetation. Most died out at the end of the last ice age.Hippocampus: A curved elevation of GRAY MATTER extending the entire length of the floor of the TEMPORAL HORN of the LATERAL VENTRICLE (see also TEMPORAL LOBE). The hippocampus proper, subiculum, and DENTATE GYRUS constitute the hippocampal formation. Sometimes authors include the ENTORHINAL CORTEX in the hippocampal formation.Genetic Load: The relative amount by which the average fitness of a POPULATION is lowered, due to the presence of GENES that decrease survival, compared to the GENOTYPE with maximum or optimal fitness. (From Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)Feeding Behavior: Behavioral responses or sequences associated with eating including modes of feeding, rhythmic patterns of eating, and time intervals.Conditioning, Eyelid: Reflex closure of the eyelid occurring as a result of classical conditioning.Tropical Climate: 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)Aquatic Organisms: Organisms that live in water.Greenhouse Effect: 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.ArtiodactylaBlinking: Brief closing of the eyelids by involuntary normal periodic closing, as a protective measure, or by voluntary action.North AmericaRats, Wistar: A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.Taste: The ability to detect chemicals through gustatory receptors in the mouth, including those on the TONGUE; the PALATE; the PHARYNX; and the EPIGLOTTIS.GABA Agonists: Endogenous compounds and drugs that bind to and activate GAMMA-AMINOBUTYRIC ACID receptors (RECEPTORS, GABA).Minor Planets: Small solar system planetary bodies including asteroids. Most asteroids are found within the gap lying between the orbits of Mars and Jupiter.Pest Control, Biological: Use of naturally-occuring or genetically-engineered organisms to reduce or eliminate populations of pests.Gene Expression Regulation: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Mutation: 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.Evolution, Molecular: The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.Nootropic Agents: Drugs used to specifically facilitate learning or memory, particularly to prevent the cognitive deficits associated with dementias. These drugs act by a variety of mechanisms. While no potent nootropic drugs have yet been accepted for general use, several are being actively investigated.Proto-Oncogene Proteins c-fos: Cellular DNA-binding proteins encoded by the c-fos genes (GENES, FOS). They are involved in growth-related transcriptional control. c-fos combines with c-jun (PROTO-ONCOGENE PROTEINS C-JUN) to form a c-fos/c-jun heterodimer (TRANSCRIPTION FACTOR AP-1) that binds to the TRE (TPA-responsive element) in promoters of certain genes.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Dinosaurs: General name for two extinct orders of reptiles from the Mesozoic era: Saurischia and Ornithischia.Protein Synthesis Inhibitors: Compounds which inhibit the synthesis of proteins. They are usually ANTI-BACTERIAL AGENTS or toxins. Mechanism of the action of inhibition includes the interruption of peptide-chain elongation, the blocking the A site of ribosomes, the misreading of the genetic code or the prevention of the attachment of oligosaccharide side chains to glycoproteins.Generalization (Psychology): The phenomenon of an organism's responding to all situations similar to one in which it has been conditioned.Brain: The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.Butterflies: Slender-bodies diurnal insects having large, broad wings often strikingly colored and patterned.Receptors, N-Methyl-D-Aspartate: A class of ionotropic glutamate receptors characterized by affinity for N-methyl-D-aspartate. NMDA receptors have an allosteric binding site for glycine which must be occupied for the channel to open efficiently and a site within the channel itself to which magnesium ions bind in a voltage-dependent manner. The positive voltage dependence of channel conductance and the high permeability of the conducting channel to calcium ions (as well as to monovalent cations) are important in excitotoxicity and neuronal plasticity.Structure-Activity Relationship: The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.Geologic Sediments: 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)Microinjections: The injection of very small amounts of fluid, often with the aid of a microscope and microsyringes.Software: Sequential operating programs and data which instruct the functioning of a digital computer.Lithium Chloride: A salt of lithium that has been used experimentally as an immunomodulator.Intellectual Disability: Subnormal intellectual functioning which originates during the developmental period. This has multiple potential etiologies, including genetic defects and perinatal insults. Intelligence quotient (IQ) scores are commonly used to determine whether an individual has an intellectual disability. IQ scores between 70 and 79 are in the borderline range. Scores below 67 are in the disabled range. (from Joynt, Clinical Neurology, 1992, Ch55, p28)Proteins: Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.Models, Statistical: 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.Oligonucleotide Array Sequence Analysis: Hybridization of a nucleic acid sample to a very large set of OLIGONUCLEOTIDE PROBES, which have been attached individually in columns and rows to a solid support, to determine a BASE SEQUENCE, or to detect variations in a gene sequence, GENE EXPRESSION, or for GENE MAPPING.Overlearning: Learning in which practice proceeds beyond the point where the act can just be performed with the required degree of excellence.Wolves: Any of several large carnivorous mammals of the family CANIDAE that usually hunt in packs.Mice, Inbred C57BLMotivation: Those factors which cause an organism to behave or act in either a goal-seeking or satisfying manner. They may be influenced by physiological drives or by external stimuli.Molecular Structure: The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.Psychological Theory: Principles applied to the analysis and explanation of psychological or behavioral phenomena.Daphnia: A diverse genus of minute freshwater CRUSTACEA, of the suborder CLADOCERA. They are a major food source for both young and adult freshwater fish.Regression (Psychology): A return to earlier, especially to infantile, patterns of thought or behavior, or stage of functioning, e.g., feelings of helplessness and dependency in a patient with a serious physical illness. (From APA, Thesaurus of Psychological Index Terms, 1994).Competitive Behavior: The direct struggle between individuals for environmental necessities or for a common goal.Yohimbine: A plant alkaloid with alpha-2-adrenergic blocking activity. Yohimbine has been used as a mydriatic and in the treatment of ERECTILE DYSFUNCTION.Adaptation, Biological: Changes in biological features that help an organism cope with its ENVIRONMENT. These changes include physiological (ADAPTATION, PHYSIOLOGICAL), phenotypic and genetic changes.Kinetics: The rate dynamics in chemical or physical systems.Biota: The spectrum of different living organisms inhabiting a particular region, habitat, or biotope.Genetics, Population: 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.Animal Migration: 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.Bivalvia: 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.Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.Neuronal Plasticity: The capacity of the NERVOUS SYSTEM to change its reactivity as the result of successive activations.Reproduction: The total process by which organisms produce offspring. (Stedman, 25th ed)Anxiety Disorders: Persistent and disabling ANXIETY.Receptor, Cannabinoid, CB1: A subclass of cannabinoid receptor found primarily on central and peripheral NEURONS where it may play a role modulating NEUROTRANSMITTER release.Fishes: A group of cold-blooded, aquatic vertebrates having gills, fins, a cartilaginous or bony endoskeleton, and elongated bodies covered with scales.Cluster Analysis: 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.Systems Biology: Comprehensive, methodical analysis of complex biological systems by monitoring responses to perturbations of biological processes. Large scale, computerized collection and analysis of the data are used to develop and test models of biological systems.Databases, Factual: Extensive collections, reputedly complete, of facts and data garnered from material of a specialized subject area and made available for analysis and application. The collection can be automated by various contemporary methods for retrieval. The concept should be differentiated from DATABASES, BIBLIOGRAPHIC which is restricted to collections of bibliographic references.Hybrid Cells: Any cell, other than a ZYGOTE, that contains elements (such as NUCLEI and CYTOPLASM) from two or more different cells, usually produced by artificial CELL FUSION.Ursidae: The family of carnivorous or omnivorous bears, having massive bodies, coarse heavy fur, relatively short limbs, and almost rudimentary tails.Inhibition (Psychology): The interference with or prevention of a behavioral or verbal response even though the stimulus for that response is present; in psychoanalysis the unconscious restraining of an instinctual process.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Polynesia: The collective name for the islands of the central Pacific Ocean, including the Austral Islands, Cook Islands, Easter Island, HAWAII; NEW ZEALAND; Phoenix Islands, PITCAIRN ISLAND; SAMOA; TONGA; Tuamotu Archipelago, Wake Island, and Wallis and Futuna Islands. Polynesians are of the Caucasoid race, but many are of mixed origin. Polynesia is from the Greek poly, many + nesos, island, with reference to the many islands in the group. (From Webster's New Geographical Dictionary, 1988, p966 & Room, Brewer's Dictionary of Names, 1992, p426)Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Life: The state that distinguishes organisms from inorganic matter, manifested by growth, metabolism, reproduction, and adaptation. It includes the course of existence, the sum of experiences, the mode of existing, or the fact of being. Over the centuries inquiries into the nature of life have crossed the boundaries from philosophy to biology, forensic medicine, anthropology, etc., in creative as well as scientific literature. (Random House Unabridged Dictionary, 2d ed; Dr. James H. Cassedy, NLM History of Medicine Division)Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Glycine Plasma Membrane Transport Proteins: A family of sodium chloride-dependent neurotransmitter symporters that transport the amino acid GLYCINE. They differ from GLYCINE RECEPTORS, which signal cellular responses to GLYCINE. They are located primarily on the PLASMA MEMBRANE of NEURONS; GLIAL CELLS; EPITHELIAL CELLS; and RED BLOOD CELLS where they remove inhibitory neurotransmitter glycine from the EXTRACELLULAR SPACE.Tumor Markers, Biological: Molecular products metabolized and secreted by neoplastic tissue and characterized biochemically in cells or body fluids. They are indicators of tumor stage and grade as well as useful for monitoring responses to treatment and predicting recurrence. Many chemical groups are represented including hormones, antigens, amino and nucleic acids, enzymes, polyamines, and specific cell membrane proteins and lipids.Chromatography, High Pressure Liquid: Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.Selection, Genetic: Differential and non-random reproduction of different genotypes, operating to alter the gene frequencies within a population.Desensitization, Psychologic: A behavior therapy technique in which deep muscle relaxation is used to inhibit the effects of graded anxiety-evoking stimuli.Temperature: 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.Substance Withdrawal Syndrome: Physiological and psychological symptoms associated with withdrawal from the use of a drug after prolonged administration or habituation. The concept includes withdrawal from smoking or drinking, as well as withdrawal from an administered drug.Anthozoa: A class in the phylum CNIDARIA, comprised mostly of corals and anemones. All members occur only as polyps; the medusa stage is completely absent.Neurons: The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Maze Learning: Learning the correct route through a maze to obtain reinforcement. It is used for human or animal populations. (Thesaurus of Psychological Index Terms, 6th ed)Meteoroids: Any solid objects moving in interplanetary space that are smaller than a planet or asteroid but larger than a molecule. Meteorites are any meteoroid that has fallen to a planetary surface. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Pyrazoles: Azoles of two nitrogens at the 1,2 positions, next to each other, in contrast with IMIDAZOLES in which they are at the 1,3 positions.Pacific Ocean

*  Mammal extinction across the Holocene | Philosophical Transactions of the Royal Society B: Biological Sciences

1995 Extinctions in Mediterranean areas. In Extinction rates (eds Lawton J. H., May R. M.), pp. 88-97. Oxford, UK: Oxford ... 2009 Holocene extinctions and the loss of feature diversity. In Holocene extinctions (ed. Turvey S. T.), pp. 263-277. Oxford, ... 2008 The predictability of extinction: biological and external correlates of decline in mammals. Proc. R. Soc. B 275, 1441-1448 ... The ghosts of mammals past: biological and geographical patterns of global mammalian extinction across the Holocene. Samuel T. ...

*  Extinction, survival or recovery of large predatory fishes | Philosophical Transactions of the Royal Society B: Biological...

Extinction, survival or recovery of large predatory fishes Message Subject (Your Name) has sent you a message from ... Extinction, survival or recovery of large predatory fishes. Ransom A. Myers, Boris Worm ... Your Name) thought you would like to see the Philosophical Transactions of the Royal Society B: Biological Sciences web site. ... i) An analysis of maximum reproductive rates predicts the collapse and extinction of sensitive species under current levels of ...

*  News: Home | IFAW - International Fund for Animal Welfare

Biological diversity is what makes the world unique. As the sum of all living organisms, biodiversity is key to the Read more » ... Individual animals are key to mitigating sixth extinction. 25 July 2017 by Azzedine Downes ...

*  IFAW - International Fund for Animal Welfare

Biological diversity is what makes the world unique. As the sum of all living organisms, biodiversity is key to the Read more » ... Small and scaly, pangolins are the world's most illegally traded mammal and in danger of extinction. While these armored ...
ifaw.org/united-states/news/gulf-mexico-dolphin-deaths-–-disgusting-disgrace "post a comment" gulf?page=6&ct=clnk

*  News: Home | IFAW - International Fund for Animal Welfare

Biological diversity is what makes the world unique. As the sum of all living organisms, biodiversity is key to the Read more » ... Wildlife Groups Seek to Save Species from Silent Extinction In response to recent scientific consensus on giraffes' ... vulnerability to extinction, five wildlife protection groups today petitioned the U.S. Fish and Wildlife Service to protect ...

*  conservation - Which species are most vulnerable to extinction? | ecology | Britannica.com

Which species are most vulnerable to extinction?: Before a species becomes extinct, it must first be rare. Some species are ... The latter strategy, an instance of biological control, is not risk-free. It involves introducing a second nonnative species to ... Since 1600 the great majority of known bird extinctions have been on islands. The problem of extinction is not just limited to ... The pathology of extinction*Rates of natural and present-day species extinction ...

*  Conservapedia Mistates Mutation - Mike the Mad Biologist

Of course, the biological reality, as opposed to the creationist fantasy, is that genes can expand their function by mutation ... Decay, scattering, extinction, defects, disasters, etc., all INCREASE over time. Besides, all mutations are harmful.-Aschlafly ... Counter: There has not been enough time for mutation to generate existing biological diversity.. * Counter: There has been ... enough time enough time to generate existing biological diversity.. * Counter: The time argument doesn't help. ...

*  Proposed wolf recovery plan would speed extinction | Albuquerque Journal

Proposed wolf recovery plan would speed extinction. By Michael J. Robinson / Conservation advocate, Center for Biological ... As seen in government responses to Freedom of Information Act requests from the Center for Biological Diversity, the draft plan ... More wolves from different populations mating with each other is the only way to stave off extinction. ...

*  Nailing jello (jelly) to the wall - creation.com

Extinction is a 'perfectly normal biological process'. Elimination of old species is as 'normal and necessary as the ... The second key to understanding the fossil record is extinction. It is why only we, Homo sapiens, are left. ... Two keys in the process of human evolution (and all evolution), they say, are punctuated equilibria and extinction. ...

*  Another Week of Climate Disruption News, July 28, 2013 - A Few Things Ill Considered

What's new on the extinction front?. *2013/07/26: TP:JR: Many Species Will Have To Evolve 10,000 Times Faster To Adapt To ... 2013/07/24: Eureka: New study reveals dangers to biological diversity from global cashmere garment industry. Snow leopard, wild ... 2013/07/22: CSM: Iberian lynx faces extinction in just 50 years, say scientists ... a stark warning that many of Europe's species may be heading for extinction, says a new report by the European Environment ...

*  Data from: Eutherian morphological disparity across the end-Cretaceous mass extinction - Dryad

In the aftermaths of mass extinction events, during radiations of clades, and in several other evolutionary scenarios, there is often a decoupling of taxonomic diversity and morphological disparity. The placental mammal radiation after the end-Cretaceous mass extinction is one of the archetypal adaptive radiations, but the change in morphological disparity of the entire skeleton has never been quantified across this important boundary. We reconstruct ancestral morphologies of 680 discrete morphological characters onto dated phylogenies of 177 mostly Cretaceous and Palaeogene eutherians (placental mammals and their stem relatives). Using a new approach to incorporate morphologies representing ghost lineages, we assess three measures of morphological disparity (sum of ranges, sum of variances and mean pairwise dissimilarity) across stage-level time bins within the Cretaceous and Palaeogene. We find that the range-based metric suggests that eutherian disparity increased ...

*  ClimateChangeFork | A blog about climate change, education, and the search for solutions in adaptation and mitigation

Significance. The strong focus on species extinctions, a critical aspect of the contemporary pulse of biological extinction, leads to a common misimpression that Earth's biota is not immediately threatened, just slowly entering an episode of major biodiversity loss. This view overlooks the current trends of population declines and extinctions. Using a sample of 27,600 terrestrial vertebrate species, and a more detailed analysis of 177 mammal species, we show the extremely high degree of population decay in vertebrates, even in common "species of low concern." Dwindling population sizes and range shrinkages amount to a massive anthropogenic erosion of biodiversity and of the ecosystem services essential to civilization. This "biological annihilation" underlines the seriousness for humanity of Earth's ongoing sixth mass extinction event.. Abstract. The population extinction pulse we describe ...

*  Geochemistry

New findings of scientists from several universities published in Science show that the Permian-Triassic mass extinction (~ 252 million years ago), the greatest extinction event of all time, was caused by ocean acidification. The researchers studied boron isotopes from marine sediments in order to reconstruct seawater pH and subsequently combined these data with quantitative modeling techniques to develop a scenario for the mass extinction. Their results show that seawater pH remained relatively stable during the first phase of the extinction, but rapidly shifted to more acidic values during the second phase, which lasted ~ 10 thousand years. This acidification of the oceans had dramatic consequences for life on Earth and is thought to be associated with the release of massive amounts of carbon, related to the volcanism of the Siberian Traps. Up to 96 % of living marine species became extinct during the Permian-Triassic mass ...

*  Methane-Producing Bacteria May Have Caused Earth's Largest Mass Extinction | Inhabitat - Green Design, Innovation, Architecture...

Researchers from MIT have found evidence that methane-spewing organisms may have been responsible for the Earth's worst mass extinction.

*  ACMS Colloquium: Assimilation and propagation of clinical data uncertainty in cardiovascular modeling | iCeNSA

Please join the Department of Applied and Computational Mathematics and Statistics today for the following colloquium: Assimilation and propagation of clinical data uncertainty in cardiovascular modeling Daniele Schiavazzi Department of Pediatrics Stanford University Abstract November 18, 2015 4:00 PM to 5:00 PM 127 Hayes-Healy Center *REFRESHMENTS WILL BE SERVED IN 154 HURLEY HALL FROM 3:30 PM TO 4:00 PM If you would like to copy this event to your calendar, please visit this link to the ACMS departmental event calendar: http://acms.nd.edu/event-calendar/ A complete list of colloquia can be found here:http://acms.nd.edu/events/acms-colloquia ...

*  Snail's demise suggests sixth mass extinction is under way | New Scientist

One hundred species every day ... species extinctions may be masked by our focus on big vertebrates, instead of tiny invertebrates that make up most of biodiversity

*  Stones and Bones: June 2008

I find it hard to believe that Tom Kabel is a science teacher in a public school. It is possible- too possible- but hard to believe. I would hope that teachers could spell, and present a reasoned, logical argument. Evolutionary biologists don't have any problem with the age of the earth. Evolution happened, and however much time is available is the amount of time it took. The pace and tempo of evolutionary change is actually an active area of study, and very practical given the current high rate of species extinctions. However, Tom wants to have dating explained. The fact is that sedimentary sequences were worked out in the late 1700s and early 1800s. The core material data for all sedimentary studies is a location were there are multiple deposited strata resting on top of one another in what are called "clean" or "conforming" contacts. It was realized over 200 years ago that the fossils contained within the various strata were a useful characteristic that could be used to correlate strata ...

Olson's Extinction: Olson's Extinction was a mass extinction that occurred in the Early Guadalupian of the Permian period and which predated the Permian–Triassic extinction event.Cambrian–Ordovician extinction eventFear conditioning: Fear conditioning is a behavioral paradigm in which organisms learn to predict aversive events. It is a form of learning in which an aversive stimulus (e.Conditioned place preference: Conditioned place preference (CPP) is a form of Pavlovian conditioning used to measure the motivational effects of objects or experiences. This paradigm can also be used to measure conditioned place aversion with an identical procedure involving aversive stimuli instead.Cell envelope antibiotic: A cell envelope antibiotic is an antibacterial that acts primarily at the level of the cell envelope.Large ornamented Ediacaran microfossil: Large ornamented Ediacaran microfossils (LOEMs) are microscopic acritarchs, usually over 100 μm in diameter, which are common in sediments of the Ediacaran period, . They largely disappear from the Ediacaran fossil record before , roughly coeval with the origin of the Ediacara biota.Matrix model: == Mathematics and physics ==Caninia (genus)Matrix population models: Population models are used in population ecology to model the dynamics of wildlife or human populations. Matrix population models are a specific type of population model that uses matrix algebra.Electroshock (wrestler)Meramec Conservation AreaStatistical relational learning: Statistical relational learning (SRL) is a subdiscipline of artificial intelligence and machine learning that is concerned with domain models that exhibit both uncertainty (which can be dealt with using statistical methods) and complex, relational structure. Typically, the knowledge representation formalisms developed in SRL use (a subset of) first-order logic to describe relational properties of a domain in a general manner (universal quantification) and draw upon probabilistic graphical models (such as Bayesian networks or Markov networks) to model the uncertainty; some also build upon the methods of inductive logic programming.EcosystemAlliance for Zero Extinction: Formed in 2000 and launched globally in 2005, the Alliance for Zero Extinction (AZE) comprises 100 non-governmental biodiversity conservation organizations working to prevent species extinctions by identifying and safeguarding sites where species evaluated to be Endangered or Critically Endangered under International Union for Conservation of Nature (IUCN) criteria only exist at one location on earth."Zero Extinction - Home.Information hypothesis of conditioned reinforcementSelf-administration: Self-administration is, in its medical sense, the process of a subject administering a pharmacological substance to him-, her-, or itself. A clinical example of this is the subcutaneous "self-injection" of insulin by a diabetic patient.Avoidance reactionBiosignal: A biosignal is any signal in living beings that can be continually measured and monitored. The term biosignal is often used to refer to bioelectrical signals, but it may refer to both electrical and non-electrical signals.Cue stick: A cue stick (or simply cue, more specifically pool cue, snooker cue, or billiards cue), is an item of sporting equipment essential to the games of pool, snooker and carom billiards. It is used to strike a ball, usually the .Explicit memory: Explicit memory is the conscious, intentional recollection of previous experiences and information. People use explicit memory throughout the day, such as remembering the time of an appointment or recollecting an event from years ago.Cocaine intoxicationTemporal analysis of products: Temporal Analysis of Products (TAP), (TAP-2), (TAP-3) is an experimental technique for studyingTimeline of historic inventionsThreshold host density: Threshold host density (NT), in the context of wildlife disease ecology, refers to the concentration of a population of a particular organism as it relates to disease. Specifically, the threshold host density (NT) of a species refers to the minimum concentration of individuals necessary to sustain a given disease within a population.Health geography: Health geography is the application of geographical information, perspectives, and methods to the study of health, disease, and health care.Exercise addiction: An exercise addiction can have harmful consequences although it is not listed as a disorder in the latest revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). This type of addiction can be classified under a behavioral addiction in which a person’s behavior becomes obsessive, compulsive, and/or causes dysfunction in a person's life.Bird trapping: Bird trapping techniques to capture wild birds include a wide range of techniques that have their origins in the hunting of birds for food. While hunting for food does not require birds to be caught alive, some trapping techniques capture birds without harming them and are of use in ornithology research.China Biologic Products, Inc.SonepiprazoleBranching order of bacterial phyla (Gupta, 2001): There are several models of the Branching order of bacterial phyla, one of these was proposed in 2001 by Gupta based on conserved indels or protein, termed "protein signatures", an alternative approach to molecular phylogeny. Some problematic exceptions and conflicts are present to these conserved indels, however, they are in agreement with several groupings of classes and phyla.Bodega Marine Reserve: Bodega Marine Reserve is a nature reserve and marine reserve on the coast of northern California, located in the vicinity of the Bodega Marine Laboratory on Bodega Head. It is a unit of the University of California Natural Reserve System, that is administered by the University of California, Davis.Appropriation (By Any Other Name): June 13, 2005Spatial ecology: Spatial ecology is a specialization in ecology and geography that is concerned with the identification of spatial patterns and their relationships to ecological phenomena. Ecological events can be explained through the detection of patterns at a given spatial scale: local, regional, or global.Evolution in Variable EnvironmentDopamine reuptake inhibitor: A dopamine reuptake inhibitor (DRI) is a type of drug which acts as a reuptake inhibitor of the monoamine neurotransmitter dopamine by blocking the action of the dopamine transporter (DAT). Reuptake inhibition is achieved when extracellular dopamine not absorbed by the postsynaptic neuron is blocked from re-entering the presynaptic neuron.List of largest volcanic eruptions: In a volcanic eruption, lava, tephra (volcanic bombs, lapilli, and ash), and various gases are expelled from a volcanic vent or fissure. While many eruptions only pose dangers to the immediately surrounding area, Earth's largest eruptions can have a major regional or even global impact, with some affecting the climate and contributing to mass extinctions.Spaced retrieval: Spaced retrieval, also known as expanded retrieval or uniform retrieval, is a learning technique, which requires users to rehearse information to be learned at different and increasing spaced intervals of time or a set uniform amount of time.Haslam, C.Biological therapy for inflammatory bowel diseaseMark IV AmphibianColes PhillipsIndex of geology articles: This is a list of all articles related to geology that cannot be readily placed on the following subtopic pages:List of geological phenomena: A geological phenomenon is a phenomenon which is explained by or sheds light on the science of geology.Microbial food web: The microbial food web refers the combined trophic interactions among microbes in aquatic environments. These microbes include viruses, bacteria, algae, heterotrophic protists (such as ciliates and flagellates).Climate change in the United Kingdom: Climate change in the United Kingdom has been a subject of protests and controversies, and various policies have been developed to mitigate its effects. It is estimated to demand at least 80-85% emission reductions in the EU during 2008-2050 with reductions as soon as technically possible.ChytridiomycotaCarneau: The Carneau is a breed of pigeon developed over many years of selective breeding primarily as a utility breed. Carneau, along with other varieties of domesticated pigeons, are all descendants from the rock pigeon (Columba livia).Septum (cephalopod)Interval boundary element method: Interval boundary element method is classical boundary element method with the interval parameters.
East Sussex Cricket Ground: East Sussex Cricket Ground was a cricket ground in St Leonards-on-Sea, Sussex. The ground was located at the site of a racecourse which had moved after 1826 from the Bulverhythe Salts.RhodolithBrachiopodUnited States Army Biological Warfare Laboratories: The U.S.Clonal Selection Algorithm: In artificial immune systems, Clonal selection algorithms are a class of algorithms inspired by the clonal selection theory of acquired immunity that explains how B and T lymphocytes improve their response to antigens over time called affinity maturation. These algorithms focus on the Darwinian attributes of the theory where selection is inspired by the affinity of antigen-antibody interactions, reproduction is inspired by cell division, and variation is inspired by somatic hypermutation.TuataraDoob decomposition theorem: In the theory of stochastic processes in discrete time, a part of the mathematical theory of probability, the Doob decomposition theorem gives a unique decomposition of every adapted and integrable stochastic process as the sum of a martingale and a predictable process (or "drift") starting at zero. The theorem was proved by and is named for Joseph L.Hadley Centre for Climate Prediction and Research: 140px|rightBiomarkers of aging: Biomarkers of aging are biomarkers that better predict functional capacity at a later age than chronological age. Stated another way, biomarkers of aging would give the true "biological age", which may be different from the chronological age.Interoceptive exposure: Interoceptive exposure is a cognitive behavioral therapy technique used in the treatment of panic disorder. It refers to carrying out exercises that bring about the physical sensations of a panic attack, such as hyperventilation and high muscle tension, and in the process removing the patient's conditioned response that the physical sensations will cause an attack to happen.Von Neumann regular ring: In mathematics, a von Neumann regular ring is a ring R such that for every a in R there exists an x in R such that . To avoid the possible confusion with the regular rings and regular local rings of commutative algebra (which are unrelated notions), von Neumann regular rings are also called absolutely flat rings, because these rings are characterized by the fact that every left module is flat.Cibicides: Cibicides is a cosmopolitan genus of benthic foraminifera known from at least as far back as the Paleocene (Loeblich & Tappan, 1988) that extends down to the present.Reward system: The reward system is a group of neural structures that are critically involved in mediating the effects of reinforcement. A reward is an appetitive stimulus given to a human or some other animal to alter its behavior.AnisomycinIntraguild predation: Intraguild predation, or IGP, is the killing and eating of potential competitors. This interaction represents a combination of predation and competition, because both species rely on the same prey resources and also benefit from preying upon one another.Peat swamp forest: Peat swamp forests are tropical moist forests where waterlogged soil prevents dead leaves and wood from fully decomposing. Over time, this creates a thick layer of acidic peat.PSI Protein Classifier: PSI Protein Classifier is a program generalizing the results of both successive and independent iterations of the PSI-BLAST program. PSI Protein Classifier determines belonging of the found by PSI-BLAST proteins to the known families.Protein primary structure: The primary structure of a peptide or protein is the linear sequence of its amino acid structural units, and partly comprises its overall biomolecular structure. By convention, the primary structure of a protein is reported starting from the amino-terminal (N) end to the carboxyl-terminal (C) end.Concentration effect: In the study of inhaled anesthetics, the concentration effect is the increase in the rate that the Fa(alveolar concentration)/Fi(inspired concentration) ratio rises as the alveolar concentration of that gas is increased. In simple terms, the higher the concentration of gas administered, the faster the alveolar concentration of that gas approaches the inspired concentration.

(1/713) Removing the threat of diclofenac to critically endangered Asian vultures.

Veterinary use of the nonsteroidal anti-inflammatory (NSAID) drug diclofenac in South Asia has resulted in the collapse of populations of three vulture species of the genus Gyps to the most severe category of global extinction risk. Vultures are exposed to diclofenac when scavenging on livestock treated with the drug shortly before death. Diclofenac causes kidney damage, increased serum uric acid concentrations, visceral gout, and death. Concern about this issue led the Indian Government to announce its intention to ban the veterinary use of diclofenac by September 2005. Implementation of a ban is still in progress late in 2005, and to facilitate this we sought potential alternative NSAIDs by obtaining information from captive bird collections worldwide. We found that the NSAID meloxicam had been administered to 35 captive Gyps vultures with no apparent ill effects. We then undertook a phased programme of safety testing of meloxicam on the African white-backed vulture Gyps africanus, which we had previously established to be as susceptible to diclofenac poisoning as the endangered Asian Gyps vultures. We estimated the likely maximum level of exposure (MLE) of wild vultures and dosed birds by gavage (oral administration) with increasing quantities of the drug until the likely MLE was exceeded in a sample of 40 G. africanus. Subsequently, six G. africanus were fed tissues from cattle which had been treated with a higher than standard veterinary course of meloxicam prior to death. In the final phase, ten Asian vultures of two of the endangered species (Gyps bengalensis, Gyps indicus) were dosed with meloxicam by gavage; five of them at more than the likely MLE dosage. All meloxicam-treated birds survived all treatments, and none suffered any obvious clinical effects. Serum uric acid concentrations remained within the normal limits throughout, and were significantly lower than those from birds treated with diclofenac in other studies. We conclude that meloxicam is of low toxicity to Gyps vultures and that its use in place of diclofenac would reduce vulture mortality substantially in the Indian subcontinent. Meloxicam is already available for veterinary use in India.  (+info)

(2/713) Tracking ancient polyploids: a retroposon insertion reveals an extinct diploid ancestor in the polyploid origin of belladonna.

Polyploidy is a prominent process in plant evolution and adaptation, but molecular phylogenetic studies of polyploids based on DNA sequences have often been confounded by their complex gene and genome histories. We report here a retroposon insertion in the nuclear gene granule-bound starch synthase I (GBSSI or "waxy") that clearly reveals the ancient hybrid history of the medically important polyploid species belladonna (Atropa belladonna) and resolves the controversy over the taxonomic group to which it belongs, the tribe Hyoscyameae (Solanaceae). Our inferences based on the pattern of presence or absence of the retroposon insertion are corroborated by phylogenetic analyses of the GBSSI gene sequences. This case may suggest that retroposons are promising molecular markers to study polyploid evolution.  (+info)

(3/713) Negative environmental perturbations may improve species persistence.

Among the factors proximally involved in the extinction of small isolated populations, genetic deterioration and temporal variation in environmental quality have been the subjects of intensive research in ecological and evolutionary sciences. However, previous theoretical studies and population viability assessments generally assumed a strict dichotomy between these two types of threat. Yet a number of empirical studies have recently suggested that the effects of genetic deterioration and environmental variation should not be considered independently, by demonstrating that the main effect of inbreeding depression lies with its tendency to exacerbate the deleterious consequences of environmental stress. Capitalizing on these results, I developed a stochastic model to examine the impact of random environmental perturbations on the persistence time of small isolated populations subject to inbreeding depression and mutation accumulation. The model assumes that spontaneous deleterious mutations have more severe effects when perturbations occur, which results in more efficient purging of the mutation load. Under this assumption, I find that negative perturbations may paradoxically improve middle- and long-term species persistence for realistic frequency of occurrence and severity distribution.  (+info)

(4/713) Invasion of an asexual American water flea clone throughout Africa and rapid displacement of a native sibling species.

The huge ecological and economic impact of biological invasions creates an urgent need for knowledge of traits that make invading species successful and factors helping indigenous populations to resist displacement by invading species or genotypes. High genetic diversity is generally considered to be advantageous in both processes. Combined with sex, it allows rapid evolution and adaptation to changing environments. We combined paleogenetic analysis with continent-wide survey of genetic diversity at nuclear and mitochondrial loci to reconstruct the invasion history of a single asexual American water flea clone (hybrid Daphnia pulexxDaphnia pulicaria) in Africa. Within 60 years of the original introduction of this invader, it displaced the genetically diverse, sexual population of native D. pulex in Lake Naivasha (Kenya), despite a formidable numerical advantage of the local population and continuous replenishment from a large dormant egg bank. Currently, the invading clone has spread throughout the range of native African D. pulex, where it appears to be the only occurring genotype. The absence of genetic variation did not hamper either the continent-wide establishment of this exotic lineage or the effective displacement of an indigenous and genetically diverse sibling species.  (+info)

(5/713) Climate change and the demographic demise of a hoarding bird living on the edge.

Population declines along the lower-latitude edge of a species' range may be diagnostic of climate change. We report evidence that climate change has contributed to deteriorating reproductive success in a rapidly declining population of the grey jay (Perisoreus canadensis) at the southern edge of its range. This non-migratory bird of boreal and subalpine forest lives on permanent territories, where it hoards enormous amounts of food for winter and then breeds very early, under still-wintry conditions. We hypothesized that warmer autumns have increased the perishability of hoards and compromised subsequent breeding attempts. Our analysis confirmed that warm autumns, especially when followed by cold late winters, have led to delayed breeding and reduced reproductive success. Our findings uniquely show that weather months before the breeding season impact the timing and success of breeding. Warm autumns apparently represent hostile conditions for this species, because it relies on cold storage. Our study population may be especially vulnerable, because it is situated at the southern edge of the range, where the potential for hoard rot is most pronounced. This population's demise may signal a climate-driven range contraction through local extinctions along the trailing edge.  (+info)

(6/713) Metapopulation extinction risk is increased by environmental stochasticity and assemblage complexity.

Extinction risk is a key area of investigation for contemporary ecologists and conservation biologists. Practical conservation efforts for vulnerable species can be considerably enhanced by thoroughly understanding the ecological processes that interact to determine species persistence or extinction. Theory has highlighted the importance of both extrinsic environmental factors and intrinsic demographic processes. In laboratory microcosms, single-species single-habitat patch experimental designs have been widely used to validate the theoretical prediction that environmental heterogeneity can increase extinction risk. Here, we develop on this theme by testing the effects of fluctuating resource levels in experimental multispecies metapopulations. We compare a three-species host-parasitoid assemblage that exhibits apparent competition to the individual pairwise, host-parasitoid interactions. Existing theory is broadly supported for two-species assemblages: environmental stochasticity reduces trophic interaction persistence time, while metapopulation structure increases persistence time. However, with increasing assemblage complexity, the effects of trophic interactions mask environmental impacts and persistence time is further reduced, regardless of resource renewal regime. We relate our findings to recent theory, highlighting the importance of taking into account both intrinsic and extrinsic factors, over a range of spatial scales, in order to understand resource-consumer dynamics.  (+info)

(7/713) Morphological and molecular phylogenetic context of the angiosperms: contrasting the 'top-down' and 'bottom-up' approaches used to infer the likely characteristics of the first flowers.

Recent attempts to address the long-debated 'origin' of the angiosperms depend on a phylogenetic framework derived from a matrix of taxa versus characters; most assume that empirical rigour is proportional to the size of the matrix. Sequence-based genotypic approaches increase the number of characters (nucleotides and indels) in the matrix but are confined to the highly restricted spectrum of extant species, whereas morphology-based approaches increase the number of phylogenetically informative taxa (including fossils) at the expense of accessing only a restricted spectrum of phenotypic characters. The two approaches are currently delivering strongly contrasting hypotheses of relationship. Most molecular studies indicate that all extant gymnosperms form a natural group, suggesting surprisingly early divergence of the lineage that led to angiosperms, whereas morphology-only phylogenies indicate that a succession of (mostly extinct) gymnosperms preceded a later angiosperm origin. Causes of this conflict include: (i) the vast phenotypic and genotypic lacuna, largely reflecting pre-Cenozoic extinctions, that separates early-divergent living angiosperms from their closest relatives among the living gymnosperms; (ii) profound uncertainty regarding which (a) extant and (b) extinct angiosperms are most closely related to gymnosperms; and (iii) profound uncertainty regarding which (a) extant and (b) extinct gymnosperms are most closely related to angiosperms, and thus best serve as 'outgroups' dictating the perceived evolutionary polarity of character transitions among the early-divergent angiosperms. These factors still permit a remarkable range of contrasting, yet credible, hypotheses regarding the order of acquisition of the many phenotypic characters, reproductive and vegetative, that distinguish 'classic' angiospermy from 'classic' gymnospermy. The flower remains ill-defined and its mode (or modes) of origin remains hotly disputed; some definitions and hypotheses of evolutionary relationships preclude a role for the flower in delimiting the angiosperms. We advocate maintenance of parallel, reciprocally illuminating programmes of morphological and molecular phylogeny reconstruction, respectively supported by homology testing through additional taxa (especially fossils) and evolutionary-developmental genetic studies that explore genes potentially responsible for major phenotypic transitions.  (+info)

(8/713) Abundance distributions imply elevated complexity of post-Paleozoic marine ecosystems.

Likelihood analyses of 1176 fossil assemblages of marine organisms from Phanerozoic (i.e., Cambrian to Recent) assemblages indicate a shift in typical relative-abundance distributions after the Paleozoic. Ecological theory associated with these abundance distributions implies that complex ecosystems are far more common among Meso-Cenozoic assemblages than among the Paleozoic assemblages that preceded them. This transition coincides not with any major change in the way fossils are preserved or collected but with a shift from communities dominated by sessile epifaunal suspension feeders to communities with elevated diversities of mobile and infaunal taxa. This suggests that the end-Permian extinction permanently altered prevailing marine ecosystem structure and precipitated high levels of ecological complexity and alpha diversity in the Meso-Cenozoic.  (+info)

threatened species

  • Comprehensive assessment of the conservation status of the 5487 wild mammal species recognized as extant since AD 1500 has shown that 25 per cent of all species for which adequate data are available are currently threatened with extinction, and that the distribution of these threatened species is geographically biased [ 2 ]. (royalsocietypublishing.org)


  • Biological diversity is what makes the world unique. (ifaw.org)
  • There has not been enough time for mutation to generate existing biological diversity. (scienceblogs.com)
  • As seen in government responses to Freedom of Information Act requests from the Center for Biological Diversity, the draft plan was substantially influenced by the anti-wolf game departments of New Mexico, Arizona, Utah and Colorado under marching orders from their governors to sharply limit the distribution and number of wolves. (abqjournal.com)


  • i) An analysis of maximum reproductive rates predicts the collapse and extinction of sensitive species under current levels of fishing mortality. (royalsocietypublishing.org)


  • Scientists describe the number of vertebrate species experiencing population declines as "biological annihilation. (the-scientist.com)


  • We explore the spatial, taxonomic and phylogenetic patterns of 241 mammal species extinctions known to have occurred during the Holocene up to the present day. (royalsocietypublishing.org)
  • Since 1600 the great majority of known bird extinctions have been on islands. (britannica.com)


  • To assess whether our understanding of mammalian threat processes has been affected by excluding these taxa, we incorporate extinct species data into analyses of the impact of body mass on extinction risk. (royalsocietypublishing.org)
  • Message Body (Your Name) thought you would like to see the Philosophical Transactions of the Royal Society B: Biological Sciences web site. (royalsocietypublishing.org)

protected areas

  • In the case of lions, wolves, and wild dogs, population size alone is a poor predictor of their local extinction, even when the animals live in protected areas. (britannica.com)


  • A further extensive series of mammalian species extinctions, population extirpations and range contractions continued across insular and continental regions into the Holocene Epoch, the current geological interval, through recent prehistory and into the historical period [ 16 ]. (royalsocietypublishing.org)
  • Large animals, by virtue of their low population densities, are at increased risk of extinction. (britannica.com)


  • We find that Holocene extinctions have been phylogenetically and spatially concentrated in specific taxa and geographical regions, which are often not congruent with those disproportionately at risk today. (royalsocietypublishing.org)
  • Although direct use of fossil data in future projections of extinction risk is therefore not straightforward, insights into extinction processes from the Holocene record are still useful in understanding mammalian threat. (royalsocietypublishing.org)
  • In sum, combined endemism and rarity are the factors that confer the greatest risk of extinction. (britannica.com)
  • Because small populations are so much more at risk than large ones, individuals of species that can readily disperse can rescue local populations on the verge of extinction. (britannica.com)


  • However, the Late Pleistocene was also characterized by large-scale climatic and associated vegetational shifts during the transition from glacial to interglacial conditions, and the nature and extent of human involvement even in these relatively well-studied regional extinctions remains the subject of considerable debate, with non-anthropogenic environmental factors often advocated as primary extinction drivers on the basis of climatic and vegetation models and archaeological data [ 26 - 32 ]. (royalsocietypublishing.org)
  • The problem of extinction is not just limited to islands, however, as the previous sections amply describe. (britannica.com)


  • The staggered timing of Late Pleistocene mammal extinctions and their close temporal association with first human colonization of different continental regions is increasingly well understood for North America [ 17 , 18 ] and Australia [ 19 - 22 ], and direct or indirect human involvement in these events is now widely accepted by most palaeontologists. (royalsocietypublishing.org)
  • Although the tiger is not considered an endemic species-it has a very large geographic range, stretching over much of eastern and southern Asia-its rarity in that range means that it is nonetheless vulnerable to extinction from human activity. (britannica.com)
  • Two keys in the process of human evolution (and all evolution), they say, are punctuated equilibria and extinction. (creation.com)
  • The human fossil record is the story of nature's tinkering, involving 'repeated evolutionary experimentation, diversification, and extinction' (p. 9). (creation.com)


  • As previously discussed, a small geographic range makes a species particularly vulnerable to global extinction. (britannica.com)