ReliabilityThe consistency of a measure or question in obtaining very similar or identical results when used repeatedly; for example, if you repeated a blood test…
Reliability must run (RMR)A unit that must run for operational or reliability reasons, regardless of economic considerations. Also called a reliability agreement.
RelicSome thing left over from a previous time period. Remnant products or evidence of early physical eras.
RelictA land surface that was once a basin (valley) floor.
ReliefCarved or molded ornament that projects from a flat surface.
Relief valveA valve which will allow air or fluid to escape if its pressure becomes higher than the valve setting.
RelocatedA term used in an advisory to indicate that a vector drawn from the preceding advisory position to the latest known position is not necessarily a…
RemediationThe cleanup or containment of a hazardous waste disposal site to the satisfaction of the applicable regulatory agency.
Remnant LowA post-tropical cyclone that no longer possesses the convective organization required of a tropical cyclone...
Remote operationOperation of mechanical features from an on-site location other than at the feature.
remote sensingMethod for determining characteristics of an object, organism or community from afar.
renaturationOf DNA, the reforming of two complementary molecules into a double-stranded structure, following heat or chemical induction of dissociation (denaturation).
RenatureThe reannealing (hydrogen bonding) of single- stranded DNA and/or RNA to form a duplex molecule.
Renewable EnergyEnergy derived from resources that are regenerative or for all practical purposes can not be depleted.
Renewable Energy Certificate (REC)A tradable certificate representing the generation attributes of energy derived from a qualified renewable energy source. In the U.S.
renewable energy resourceAn energy resource that can be replaced as it is used. Renewable energy resources include solar, wind, geothermal, hydro, and biomass.
Renewable energy sourceAn energy source that is replenished continuously in nature or that is replaced after use through natural means. Sustainable energy source.
Renewable Fuels StandardA regulation created under the Energy Policy Act of 2005 and implemented by the U.S.
Renewable resourcesRenewable energy resources are naturally replenishable, but flow limited. They are virtually inexhaustible in duration but limited in the amount of energy…
renninAn enzyme, secreted by cells lining the stomach in mammals, responsible for the clotting of milk. Used in the manufacture of certain dairy products.
repeat unitA sequence of nucleotide s that occurs repeatedly, often in a head-to-tail arrangement (tandemly).
Repetition/replicationThere are four plots in a repetition/replication, the early, mid and late seral treatment plots and a control plot.
Repetitive DNADNA sequences that are present in a genome in many copies, some of it originating from retrotransposon activity.
replacementThe addition of a cloned corrected copy of a defective gene. See: homogenotization.
replacement therapyThe administration of metabolites, co-factors or hormones that are deficient as the result of a genetic disease.
replica platingDuplicating a population of bacterial colonies growing on agar medium in one Petri plate to agar medium in another Petri plate.
replicaseA viral enzyme necessary for the replication of the virus in the host cell.
ReplicationThe in vivo synthesis of double-stranded DNA by copying from a single-stranded template.
replication forkY shaped structure associated with DNA replication. It represents the point at which the strands of double-stranded DNA are separated so that replication…
replicative form(Abbreviation: RF). The molecular configuration of viral nucleic acid that is the template for replication in the host cell.
RepliconA chromosomal region containing the DNA sequences necessary to initiate DNA replication processes.
replisomeThe complete replication apparatus, present at a replication fork, that carries out the replication of DNA.
ReportFormatted output of a system providing specific information.
Reportable discharge of oil (40 CFR 110.3)Harmful quantities of oil discharged or released to navigable waters of the United States are any amount that violates State water quality standards…
Reportable quantitiesQuantities of hazardous substances which require notification to the National Response Center and the appropriate state agency.
Reporter geneA gene that encodes a product that can be readily assayed. Used as to confirm the incorporation of a transgene into, organ or tissue, and as a means of…
repressible enzymeAn enzyme whose activity can be diminished by the presence of a regulatory molecule.
repressible geneA gene whose expression can be diminished or extinguished by the presence of a regulatory molecule.
repressionInhibition of transcription by preventing RNA polymerase from binding to the transcription initiation site.
repressorA DNA-binding protein in prokaryotes that blocks gene transcription by binding to the operator.
reproduction1. Sexual reproduction: the regular alteRNA tion of meiosis and fertilization which provides for the production of offspring.
Reproductive cloningSomatic cell nuclear transfer used for the production of a fetus and delivery of a live offspring that is genetically identical the donor of the somatic…
ReptileCold-blooded vertebrate of the class Reptilia whose skin is usually covered in scales or scutes.
repulsionA double heterozygote in which the dominant (or wild-type) allele at one locus and the recessive (or mutant) allele at a second linked locus occur on the…
Reserve generating capacityExtra generating capacity available to meet unanticipated capacity demand for power in the event of generation loss due to scheduled or unscheduled…
Reserve marginThe percentage of installed capacity exceeding the expected peak demand during a specified period.
ReservedFor purposes of the National System of MPAs, must be established by and currently subject to federal, state, commonwealth, territorial, local, or tribal…
Reserved Water RightA special water right accompanying federal lands (military reservations, national parks, forests, or monuments) or Indian reservations.
Reserved worksFacilities operated and maintained by Reclamation.
ReservoirA reservoir of an infectious agent, such as a virus, is any animal, person, plant, soil, substance—or combination of any of these — in which the…
Reservoir AreaThe surface area of a reservoir when filled to normal water level.
Reservoir capacityThe capacity of the reservoir, usually in acre-feet. Dam design and reservoir operation utilize reservoir capacity and water surface elevation data.
Reservoir capacity allocations (RCA) sheetA summary of acre-feet allocations of water, to such purposes as surcharge, exclusive flood control capacity, joint use capacity, active conservation…
Reservoir inflowThe amount of water entering a reservoir expressed in acre-feet per day or cubic feet per second.
Reservoir VolumeThe volume of a reservoir when filled to normal pool or water level.
Residence TimeThe average time spent in a reservoir by an individual atom or molecule. With respect to greenhouse gases, residence time usually refers to how long a…
Resident fishFish species that complete their entire life cycle in freshwater. Non-anadromous fish. An example is rainbow trout.
Residual fuel oilHeavy fuel oil produced from the residue in the fractional distillation process rather than from the distilled fractions. No.
Residual HauntingRepetitive paranormal activity resulting from the energy imprint of a person or event in time.
Residual Layerthe elevated portion of a convective boundary layer that remains after a stable boundary layer develops at the ground (usually in late afternoon or early…
Residual MoistureAtmospheric moisture which lingers over an area after the main weather system has departed.
residue1. See: polymer. 2. Materials remaining after degradation and/or attempted removal, e.g. pesticide residues in food.
residues, biomassByproducts from processing all forms of biomass that have significant energy potential.
ResiduumUnconsolidated, weathered, or partly weathered mineral material that accumulates by disintegration of bedrock in place.
ResilienceAbility of any system to resist or to recover from stress or hardship.
ResistanceThe ability of an organism to develop ways to be impervious to specific threats to their existence.
resistance factorA plasmid that confers antibiotic resistance to a bacterium.
Resistance HeatingA type of heating system that provides heat from the resistance of an electrical current flowing through a conductor.
Resistance managementStrategies that can delay the onset of resistance. For insect resistance management, this includes the use of a refuge in which the insect will not be…
Resistive Voltage DropThe voltage developed across a cell by the current flow through the resistance of the cell.
ResistorAn electrical device that resists electric current flow.
resonanceThe state of a system in which an abnormally large vibration is produced in response to an external stimulus, occurring when the frequency of the stimulus…
Resource Conservation and Recovery Act (RCRA)The primary goals of the Resource Conservation and Recovery Act (RCRA) are to protect human health and the environment from the potential hazards of waste…
Resource Management PlanA written plan that addresses the existing resources of an area and provides future objectives, goals, and management direction.
Resource Management Plan (RMP)A land use plan that establishes land use allocations, multiple use guidelines, and management objectives for a given planning area.
Resource RecoveryThe process of converting municipal solid waste to energy and/or recovering materials for recycling.
Resource valuesA resource, natural or social, that is found in an area. Resource values may have varying levels of significance.
RespirationThe process whereby living organisms convert organic matter to CO2, releasing energy and consuming O2.
Response spectrumA plot of the maximum response of a series of single-degree-of-freedom damped oscillators (elastic systems) as a function of their natural periods, or…
Response TimeThe amount of time in which it will take a watershed to react to a given rainfall event.
rest periodA physiological condition of viable seed s, buds or bulbs that prevents growth even in the presence of otherwise favourable environmental conditions.
restitution nucleusA single nucleus arising from a failure of nuclear division, either during meiosis, in which a gamete is formed with the unreduced chromosome number; or…
restriction endonucleaseA class of enzymes that cut DNA after recognizing a specific sequence. The three types of restriction endonuclease are: I.
Restriction endonuclease (enzyme)A class of endonucleases that cleaves DNA after recognizing a specific sequence, such as BamH1 (GGATCC), EcoRI (GAATTC), and HindIII (AAGCTT). Type I.