Science — page 122 of 132

13,110 terms including subtopics (0 terms filed directly here)

Science terms

Transaction costs Costs, such as commissions and spreads, incurred when buying or selling assets. Large bid-ask spreads are an indication of high transaction costs.
Transaminase An enzyme that catalyzes chemical reactions in the body in which an amino group is transferred from a donor molecule to a recipient molecule.
Transcapsidation The partial of full coating of the nucleic acid of one virus with a coat protein of a differing virus. See Coat protein.
Transcript a written copy of spoken or recorded material which is the official or legal copy of a court hearing, also called a court reporter’s transcript.
Transcription In biology, the process by which a cell makes an RNA copy of a sequence of DNA that is a gene.
Transcription factor A protein that regulates the transcription of genes.
Transcription factors Specialized proteins that bind to specific sites on DNA and turn on or turn off the expression of different sets of genes.
transcription unit A segment of DNA that contains signals for the initiation and termination of transcription, and is transcribed into one RNA molecule.
transcriptional anti-terminator A protein that prevents RNA polymerase from terminating transcription at specific transcription termination sequences.
transcriptional roadblock A DNA -binding protein which affects the rate at which RNA polymerases transcribe genes.
Transcriptome The full complement of activated genes, mRNAs, or transcripts in a particular tissue at a particular time
Transdifferentiation The ability of a particular cell of one tissue, organ or system, including stem or progenitor cells, to differentiate into a cell type characteristic of…
transducer A device that converts electrical energy to sound energy, or the reverse. Typically associated with depth finders or fish finders.
Transducing phage See Transduction.
Transduction The transfer of DNA sequences from one bacterium to another via lysogenic infection by a bacteriophage (transducing phage).
transesterification A chemical process which reacts an alcohol with the triglycerides contained in vegetable oils and animal fats to produce biodiesel and glycerin.
Transfection The uptake and expression of a foreign DNA sequence by cultured eukaryotic cells.
Transfer DNA See T\-DNA.
Transfer of Development Rights (TDR) (TDR) A system that assigns development rights to parcels of land and gives landowners the option of using those rights to develop or to sell their land.
Transfer point. See turning point.
transfer RNA See: tRNA.
Transfer RNA (tRNA) See tRNA.
transferase A class of enzymes that catalyses the transfer of a group of atoms from one molecule to another.
Transferred works Facilities owned by Reclamation, but operated and maintained by an irrigation district or other entity.
Transform fault See Fault, transform
Transformant In prokaryotes, a cell that has been ge- netically altered through the uptake of foreign DNA.
transformation (TRANZ-for-MAY-shun) In medicine, the change that a normal cell undergoes as it becomes malignant.
Transformation efficiency The number of bacterial cells that uptake and express plasmid DNA divided by the mass of plasmid used (in transformants/microgram). (See Transformation.)
transformation efficiency or frequency The fraction of a cell population that takes up and integrates the introduced transgene; expressed as the number of transformed cells recovered divided by…
Transformed flow net A flow net whose boundaries have been properly modified (transformed) so that a net consisting of curvilinear squares can be constructed to represent flow…
Transformer An electromagnetic device that changes the voltage of alternating current electricity.
Transforming oncogene A gene that upon transfection converts a previously immortalized cell to the malignant phenotype. (See Oncogene.)
Transgene See Transgenic.
transgenesis The introduction of a gene or genes into animal or plant cells, which leads to the transmission of the input gene (transgene ) to successive generations.
Transgenic An organism in which a foreign DNA gene (a transgene) is incorporated into its genome early in de- velopment.
Transgenic animal Genetically enginnered animal or offspring of genetically engineered animals. The transgenic animal usually contains material from at lease one unrelated…
Transgenic plant Genetically engineered plant or offspring of genetically engineered plants. The transgenic plant usually contains material from at least one unrelated…
transgressive variation The appearance, in a segregating generation, of individuals showing expression of a trait outside the extremes defined by the parent of the cross that was…
transient expression Short-term activity of a transgene following its introduction into. Transient expression usually implies non-integration of the transgene into the.
Transit A surveying instrument that can measure both vertical and horizontal angles.
Transit Nodes Stops along a public transportation route where people board and disembark, often where one or more routes intersect with each other.
Transit-Oriented Development (TOD) (TOD) The development of housing, commercial space, services, and job opportunities in close proximity to public transportation.
transition These are where one type of bottom material or structure changes to another, for instance, a rock pile to solid rock, or sand to gravel.
Transition Region Area of the Sun’s atmosphere with temperatures between those of the chromosphere and the corona, 20,000 and 1,000,000 K (35,000 and 1,800,000°F)…
transition stage The period between juvenile and reproductive stages of growth.
Transition zone (semipervious zone) A substantial part of the cross section of an embankment dam comprising material whose grading is of intermediate size between that of an impervious zone…
Transition-state intermediate In a chemical reaction, an unstable and high-energy configuration assumed by reactants on the way to making products.
Translation The process of converting the genetic infor- mation of an mRNA on ribosomes into a polypeptide.
translational initiation signal See: initiation codon.
translational start codon See: initiation codon.
translational stop signal See: termination codon.
Translocation (TRANZ-loh-KAY-shun) A genetic change in which a piece of one chromosome breaks off and attaches to another chromosome.
Transmission To cause spread of germs.
Transmission and Distribution Losses The losses that result from inherent resistance in electrical conductors and transformation inefficiencies in distribution transformers in a transmission…
Transmission corridor An electric or pipeline transmission corridor is a route approved on public lands, in a BLM or other federal agency land use plan, as a location that may…
Transmission line A set of electrical current conductors, insulators, supporting structures, and associated equipment used to move large quantities of power at high…
Transmission Lines Transmit high-voltage electricity from the transformer to the electric distribution system.
Transmission loading relief (TLR) (TLR) A NERC procedure that allows reliability coordinators to curtail transactions (among other actions) to mitigate potential or actual operating security…
Transmissivity The rate at which water of the prevailing kinematic viscosity is transmitted through a unit width of the aquifer under a unit hydraulic gradient.
Transmitter Sends the electronic return data directly to the IRS.
Transmutation The transformation of one element into another by a nuclear reaction.
Transparency Transparency is a measure of how much information you have about the markets where you invest, the corporations whose stocks or bonds you buy, or the…
Transpiration The process by which water in plants is transferred into water vapor in the atmosphere. Evaporation of water through the leaves of plants.
Transplantation (tranz-plan-TAY-shun) The replacement of tissue with tissue from the person's own body or from another person.
Transplantation biology The science that studies the transplantation of organs and cells. Transplantation biologists investigate scientific questions to understand why foreign…
transport To move or be conveyed from one place to another. In the context of environmental contamination, a contaminant is transported from one location to another…
Transport capacity The capacity of a river to carry sediment in suspension or to move sediment along the riverbed. Usually expressed as mass per unit of time.
Transport Wind The average wind over a specified period of time within a mixed layer near the surface of the earth.
Transportation demand management strategies (TDM) TDM is a general term for strategies that result in more efficient use of transportation resources, including incentives to reduce driving, use…
Transportation Efficiency Act for the 21st Century (ISTEA/TEA-21) (ISTEA/TEA-21) Federal legislation that encompasses all transportation regulation and funding (Inter-modal Surface Transportation Efficiency Act was the original title).
Transportation Efficiency Act for the 21st Century (TEA-21) (TEA-21) Federal legislation that encompasses all transportation regulation and funding (Inter-modal Surface Transportation Efficiency Act was the original title).
Transportation sector Consists of private and public passenger and freight transportation, as well as government transportation, including military operations.
Transposable element A class of DNA sequences that can move from one chromosomal site to another.
Transposable genetic element See Transposon.
transposase An enzyme encoded by a that catalyses the movement of a DNA sequence to a different site in a DNA molecule.
transposition The movement of a DNA segment within the genome of an organism.
transposon Synonym of transposable genetic element.
Transposon (transposable, or movable genetic element) A relatively small DNA segment that has the ability to move from one chromosomal position to another.
transposon tagging A method of gene isolation that exploits the disruption of normal gene expression that is the result of an insertion of a transposon within, or close to…
Transverse Pertaining to or extending along the short axis, or width, of a structure. Perpendicular to or across the long axis, or length, of a structure.
Transverse Bands Bands of clouds oriented perpendicular to the flow in which they are embedded. They often are seen best on satellite photographs.
Transverse Rolls Elongated low-level clouds, arranged in parallel bands and aligned parallel to the low-level winds but perpendicular to the mid-level flow.
transversion The substitution in DNA or RNA of one purine by a pyrimidine or vice versa. See: transition, base substitution.
Trapezoidal weir. See Cipolletti weir.
Trapper A valley or basin in which cold air becomes trapped or pooled.
Trash Rack A screen located at an intake to prevent the ingress of debris.
Trash rake A device that is used to remove debris which has collected on a trashrack to prevent blocking the associated intake.
Trashrack A metal or reinforced concrete structure placed at the intake of a conduit, pipe, or tunnel that prevents entrance of debris over a certain size.
Trashrake A device that is used to remove debris which has collected on a trashrack to prevent blocking the associated intake.
Travel Time Time measured from the start of a dam breach to flooding at a particular location.
Traveling Grate A furnace grate that moves fuel through the combustion chamber.
Travertine A sedimentary rock formed by the precipitation of carbonate minerals from solution in ground and surface waters, and/or geothermal hot-springs.
Tree measurement sale A type of timber sale contract in which the buyer and seller agree upon the volume at the time of the sale.
tree rings a pattern observed in tree trunks, in which one band is usually equivalent to one year's growth.
Trellis An architectural feature used to shade exterior walls; usually made of a lattice of metal or wood; often covered by vines to provide additional summertime…
Tremie A device used to place concrete or grout under water.
Trench(es). See ditch.
Trestle A bridge, usually of timber or steel, that has a number of closely spaced supports between the abutments.
tri-hybrid The hybrid offspring of a cross between parents carrying contrasting alleles at three loci.
Triaxial shear test A test in which a specimen of soil or rock encased by an impervious membrane is subjected to a confining pressure and then loaded axially to failure.