Ampicillin (beta-lactamase)An antibiotic derived from penicillin that prevents bacterial growth by interfering with cell wall synthesis.
ampliconThe product of a DNA amplification reaction. See: polymerase chain reaction.
Amplification1. Creation of many copies of a segment of DNA by the polymerase chain reaction. 2. Treatment (e.g.
amplified fragment length polymorphism(Abbreviation: AFLP). A type of DNA marker, generated by the PCR amplification of restriction endonuclease treated DNA.
AmplifierA device used to increase the strength of an analog signal
AmplifyTo increase the number of copies of a DNA sequence, in vivo by inserting into a cloning vector that replicates within a host cell, or in vitro by…
AmplitudeThe maximum magnitude of a quantity. Often used to refer to the maximum height of a wave.
AMVERAutomated Mutual Assistance Vessel Rescue System. A system operated by the U.S.
AMVER/SEASA software program created by the National Weather Service intended to efficiently generate AMVER and VOS reports as part of a cooperative effort.
amylase(AM-il-aze) An enzyme that helps the body digest starches.
amylolyticThe capability of enzymatically degrading starch into sugars.
amylopectinA polysaccharide comprising highly branched chains of glucose residues. The water-insoluble portion of starch.
amyloseA polysaccharide consisting of linear chains of 100-1000 glucose residues. The water-soluble portion of starch.
anabolic pathwayA pathway by which a metabolite is synthesized; a biosynthetic pathway.
anabolismOne of the two subcategories of metabolism, referring to the building up of complex organic molecules from simpler precursors.
AnabranchA diverging branch of a river which re-enters the main stream.
AnadromousFish that live most of their adult life in saltwater but spawn in freshwater.
Anadromous fishFish that hatch in freshwater, migrate to the ocean to mature, then return to freshwater to spawn. An example is salmon.
AnaerobeAn organism that grows in the absence of oxygen. See Aerobe.
AnaerobicAn environment or condition in which molecular oxygen is not available for chemical, physical or biological processes.
Anaerobic BacteriaMicroorganisms that live in oxygen deprived environments.
Anaerobic decompositionThe breakdown of molecules into simpler molecules or atoms by microorganisms that can survive in the partial or complete absence of oxygen.
Anaerobic DigesterA device for optimizing the anaerobic digestion of biomass and/or animal manure, and possibly to recover biogas for energy production.
anaerobic digestionDigestion of materials in the absence of oxygen. See: anaerobic respiration.
Anaerobic LagoonA holding pond for livestock manure that is designed to anaerobically stabilize manure, and may be designed to capture biogas, with the use of an…
Anaerobic organismAn organism that does not need oxygen to stay alive. See anaerobic.
anaerobic respirationRespiration in which foodstuffs are partially oxidized, with the release of chemical energy, in a process not involving atmospheric oxygen.
analogIn chemistry, a substance that is similar, but not identical, to another.
analog signalA signal, such as voice, that varies in a continuous manner.
analogousFeatures of organisms or molecules that are superficially or functionally similar but have evolved in a different way or contain different compounds.
AnalysisA process in which anything complex is separated into simple or less complex parts.
anaphaseThe stage of mitosis or meiosis during which the daughter chromosomes migrate to opposite poles of the cell (toward the ends of the spindle ).
anchor geneA gene that has been positioned on both the physical map and the linkage map of a chromosome, and thereby allows their mutual alignment.
Anchor IceSubmerged Frazil ice attached or anchored to the river bottom, irrespective of its formation.
Anchor Ice DamAn accumulation of anchor ice which acts as a dam and raises the water level.
Ancillary servicesThose services necessary to support the transmission of electric power from seller to purchaser, given the obligations of control areas and transmitting…
AndesiteVolcanic rock (or lava), characteristically medium dark in color and containing 54 to 62 percent silica and moderate amounts of iron and magnesium…
androgen(AN-droh-jen) A type of hormone that promotes the development and maintenance of male sex characteristics.
androgenesisMale parthenogenesis, i.e. the development of a haploid embryo from a male nucleus.
Anemia(a-NEE-mee-a) A condition in which the number of red blood cells is below normal.
AnemometerAn instrument for measuring the force or velocity of wind; a wind gauge.
AnemorumbographAnemorumbograph Russian anemograph (recording anemometer) which is equipped with a device to record the wind direction in addition to wind speed.
AnemorumbometerAnemorumbometer Russian anemometer combined with a vane to determine the wind direction.
Aneroid BarometerAn instrument for measuring atmospheric pressure in which a needle, attached to the top of an evacuated box, is deflected as changes in atmospheric…
Aneuploid(an you ployd') describes an abnormal (not normal) amount of DNA in cells.
AngelsRadar echoes caused by birds, insects, and localized refractive index discontinuities.
angiogenesis(AN-jee-oh-JEN-eh-sis) Blood vessel formation. Tumor angiogenesis is the growth of new blood vessels needed for tumors to grow.
angiogeninOne of the human angiogenic growth factors. In addition to stimulating (normal) blood vessel formation, angiogenin levels are correlated with placenta…
angiospermA division of the plant kingdom that includes all flowering plants, i.e. vascular plants in which double fertilization occurs resulting in development of…
Angle of IncidenceIn reference to solar energy systems, the angle at which direct sunlight strikes a surface; the angle between the direction of the sun and the…
Angle of InclinationIn reference to solar energy systems, the angle that a solar collector is positioned above horizontal.
Angle of obliquityThe angle between the direction of the resultant stress or force acting on a given plane and the normal to that plane.
Angle of ReflectionThe angle at which a reflected ray of energy leaves a reflecting surface. It is measured between the outgoing ray and a perpendicular to the surface at…
Angle of reposeAngle between the horizontal and the maximum slope that a particular soil or geologic material assumes through natural processes.
Angle of viewThe angle, both vertical and horizontal, between a viewer's line of sight and the landscape being viewed.
Angle of wall frictionAngle between the abscissa and the tangent of the curve representing the relationship of shearing resistance to normal stress acting between soil and…
Angler-dayThe time spent fishing by one person for any part of a day.
Angstrom UnitA unit of length named for A.J. Angstome, a Swedish spectroscopist, used in measuring electromagnetic radiation equal to 0.000,000,01 centimeters.
Angular resolutionThe smallest angular size that the instrument can resolve.
Angular SizeThe size of an object as viewed from the earth. For example, the moon subtends (covers) an angle of 1/2 of a degree.
AnhydrousA compound that does not contain water. For example, fuel ethanol is referred to as "anhydrous ethanol" because most of the water has been removed.
animal cell immobilizationEntrapment of animal cells in some solid material in order to produce some natural product or genetically engineered protein.
animal modelAn animal with a disease either the same as or like a disease in humans. Animal models are used to study the development and progression of diseases and…
Animal unitA unit of measure for rangeland livestock equivalent to one mature cow or five sheep or five goats, all over 6 months of age.
Animal Unit (AU)A measurement of herd size used in the dairy industry. One animal unit is equal to 1000 pounds of animals. For example, a 1,200-pound cow equals 1.2 AU.
Animal Unit Month (AUM)A standardized unit of measurement of the amount of forage required by an animal unit for one month.
AnionA negatively charged ion in an electrolyte solution, attracted to the anode under the influence of a difference in electrical potential. See cation.
Anisotropic massA mass having different properties in different directions at any given point.
AnisotropyThe difference in the property of a system with changes in direction. In this case, anisotropy refers to the difference in the temperature of the cosmic…
AnnealThe pairing of complementary DNA or RNA sequences, via hydrogen bonding, to form a double-stranded polynucleotide.
Annex (functional)An emergency operations plan element that describes the jurisdiction's plan for functioning in that component area of activity during emergencies.
Annex I Countries/PartiesGroup of countries included in Annex I (as amended in 1998) to the United Nations Framework Convention on Climate Change, including all the developed…
Annex I PartiesIndustrialized countries that, as parties to the Framework Convention on Climate Change, have pledged to reduce their greenhouse gas emissions by the year…
AnnexationA change in existing community boundaries resulting from the incorporation of additional land.
Annihilated/annihilationA process in which a particle meets its corresponding antiparticle and both disappear.
annotationAdding pertinent information such as gene coded for, amino acid sequence, or other commentary to the database entry of raw sequence of DNA bases.
annualFor FDM purposes, you are an annual filer if last year you filed an OGE Form 450 (or an OGE Form 450-A).
Annual energy costVariable costs relating to energy production in a year, usually espressed in mills per kilowatt-hour.
Annual inspection (AI)Annual inspections of a dam and appurtenant facilities are conducted by the local operating office.
Annual load factorThis factor is equal to energy generated in a year divided by the product of the peak demand for that year and the number of total hours in a year.
Annual Load FractionThat fraction of annual energy demand supplied by a solar system.
Annual operating costThis is a general term which is sometimes called annual operating expense and includes all annual operation and maintenance expense, wheeling, purchased…
Annual Solar SavingsThe annual solar savings of a solar building is the energy savings attributable to a solar feature relative to the energy requirements of a non-solar…
Annual work planAnnual budget document that describes proposed work to be performed at a specific Bureau of Reclamation project, and details the amount of funds required.
Annualized loss of lifeThe sum of the probability of dam failure multiplied by the annual probability of the loading and the estimated number of lives that would be lost…