Science — page 118 of 132

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

Science terms

syndrome (SIN-drome) A set of symptoms or conditions that occur together and suggest the presence of a certain disease or an increased chance of developing the…
synergid One of the two haploid nuclei at the micropylar end of the embryo sac of higher plants. The third nucleus is the egg.
synergism An interaction between two organisms (e.g. Rhizobium and legumes) in which the growth of one is helped by the other. Opposite: antagonism.
Syngamy Synonym of fertilization.
Syngas A syntheses gas produced through gasification of biomass. Syngas is similar to natural gas and can be cleaned and conditioned to form a feedstock for…
Syngeneic (SIN-juh-NAY-ik) Having to do with individuals or tissues that have identical genes.
synkaryon The initial of the zygote, formed by the fusion of the gametic nuclei upon fertilization.
SYNOP Synoptic - relating to the general weather pattern over a wide region, such as areas of high and low pressure or frontal boundaries, as opposed to…
Synopsis A broad discussion of the weather pattern expected across any given area, generally confined to the 0-48 hour time frame.
Synoptic analysis Synoptic analysis The study of the synoptic observation data plotted on synoptic charts aimed at analysis of the atmospheric disturbances (for example…
Synoptic chart Synoptic chart A weather chart reflecting the state of the atmosphere over a large area at a given moment.
Synoptic Code Rules and procedures established by the World Meteorological Organization(WMO) for encoding weather observations.
Synoptic hour Synoptic hour Hour (UTC) determined by international agreement at which meteorological observations are made simultaneously throughout the world.
Synoptic meteorology Synoptic meteorology The study and analysis of synoptic weather information (synoptic charts, synoptic weather observations).
Synoptic Scale The spatial scale of the migratory high and low pressure systems of the lower troposphere, with wavelengths of 1000 to 2500 km.
Synoptic Track Weather reconnaissance mission flown to provide vital meteorological information in data sparse ocean areas as a supplement to existing surface, radar…
Synoptic Weather Weather occurring over a wide region on time scales exceeding 12 hours.
Synoptic weather observation Synoptic weather observation A surface weather observation, made at periodic times (usually at 3-hourly and 6-hourly intervals specified by the World…
SYNS Synopsis
Synteny The occurrence of two or more loci on the same chromosome, without regard to their genetic linkage.
Synthesis of Nuclei Combining protons and neutrons to form nuclei.
Synthetic earthquake Earthquake time history records developed from mathematical models that use white noise, filtered white noise, and stationary and nonstationary filtered…
Synthetic fertilizer Commercially prepared mixtures of plant nutrients such as nitrates, phosphates, and potassium applied to the soil to restore fertility and increase crop…
Synthetic natural gas (SNG) A manufactured product chemically similar in most respects to natural gas, resulting from the conversion or reforming of petroleum hydrocarbons.
syringyl A component of lignin, normally only found in hardwood lignins. It has a six-carbon aromatic ring with two methoxyl groups attached.
SYS System
System Physically connected generation, transmission, and distribution facilities operated as an integrated unit under one central management, or operating…
System Mix The proportion of electricity distributed by a power provider that is generated from available sources such as coal, natural gas, petroleum, nuclear…
Systematic Errors Measurement errors that are not random.
Syzygy In solar-terrestrial terms, the instance (new moon or full moon) when the earth, sun, and moon are all in a straight line.
T Abbreviation for thymine.
T cell One type of white blood cell that attacks virus-infected cells, foreign cells, and cancer cells.
T cell receptor An antigen -binding protein, located on the surface of mammalian killer T cells, which mediates the cellular immune response.
T cells A type of white blood cell that is of crucial importance to the immune system. Immature T cells migrate to the thymus gland in the upper chest cavity…
T lymphocyte One type of white blood cell that attacks virus-infected cells, foreign cells, and cancer cells.
T Rolls Transverse Rolls - elongated low-level clouds, arranged in parallel bands and aligned parallel to the low-level winds but perpendicular to the mid-level…
T-cell-mediated (cellular) immune response The synthesis of antigen-specific T cell receptors and the development of killer T cells in response to an encounter of immune system cells with an…
T-DNA The DNA segment of the Ti plasmid, present in pathogenic Agrobacterium tumefaciens, that is transferred to plant cells and inserted into the plant's DNA…
T-DNA (transfer DNA, tumor-DNA) The transforming region of DNA in the Ti plasmid of Agrobacterium tumefaciens.
T0, T1 and T2 Successive generations of plants following a transformation event. The parent transformed plant is T0, its immediate progeny is T1, and the progeny of the…
T0, T1 and T2 cell .
T4 DNA ligase An enzyme, present in bacteria infected with bacteriophage T4, which catalyses the joining (ligation ) of, and repairs nicks in, duplex DNA molecules.
TAF Terminal Aerodrome Forecast
TAFB Tropical Analysis and Forecast Branch (of the TPC)
tag See: label.
Tagout The placement of a tagout device on an energy isolating device, in accordance with an established procedure, to indicate that the energy isolating device…
Tagout device A prominent warning device, such as a tag and a means of attachment, which can be securely fastened to an energy isolating device in accordance with an…
Tail Cloud A horizontal, tail-shaped cloud (not a funnel cloud) at low levels extending from the precipitation cascade region of a supercell toward the wall cloud (i.
Tail-End Charlie Slang for the thunderstorm at the southernmost end of a squall line or other line or band of thunderstorms.
tailing The in vitro addition, to the 3'-hydroxyl ends of a double-stranded DNA molecule, of multiple copies of a single nucleotide by the enzyme terminal…
Tailings Second grade or waste material separated from pay material during screening or processing.
Tailings dam. See mine tailings dam.
Tailpipe Emissions Emissions produced through fuel combustion during a vehicle's operation.
Tailrace. See afterbay.
Tailwater The water in the natural stream immediately downstream from a dam. The elevation of water varies with discharge from the reservoir.
Tailwater Height Height of water immediately downstream of the dam. (Various datums may be used.)
Tainter gate A term used by the Corps of Engineers to describe radial gates (see gate).
Take Under the Bald and Golden Eagle Protection Act, it means to pursue, shoot, shoot at, poison, wound, kill, capture, trap, collect, destroy, molest, or…
Taking A taking occurs when a government action violates the 5th Amendment property rights of a landowner by taking a piece of property without offering fair…
Tallow Animal fat that can be used to produce biodiesel.
Talus Rock debris accumulated at the base of the cliff or slope from which they have broken off.
Tamp To pound or press soil to compact. To firmly compact earth during backfilling.
Tamper A tool for compacting soil in spots not accessible to rollers.
Tamping A method of compacting soil using the impact of a power or hand tamper on the surface of the soil placed.
Tamping roller One or more steel drums, fitted with projection feet, used to densify soil. See sheepsfoot roller.
Tandem A pair in which one part follows the other.
tandem array See: tandem repeat.
tandem repeat Two (or more) contiguous identical DNA sequences. The orientation can be either head-to-tail, or head-to-head.
Tandem repeat sequences Multiple copies of the same base sequence on a chromosome; used as markers in physical mapping. See also: physical map
Tangent A line that touches a circle and is perpendicular to its radius at the point of contact.
tank bioreactor A fermentation vessel designed to grow large scale quantities of a micro-organism (bacteria, yeast or fungi).
Tankless Water Heater A water heater that heats water before it is directly distributed for end use as required; a demand water heater.
tap root Root system in which the primary root has a much larger diameter than any lateral roots (e.g. carrot). Opposite: fibrous root.
Taproot A big root that grows downward from the base of a tree.
Taq polymerase A heat-stable DNA polymerase isolated from the bacterium Therrnus aquaticus, used in PCR. (See Polymerase.)
TAR A liquid product of thermal processing of carbonaceous materials.
Tar sand Swamp-like deposit of a mixture of fine clay, sand, water, and variable amounts of tar-like heavy oil known as bitumen.
Target In diagnostic tests, the molecule or nucleic acid sequence assayed in a sample.
target site duplication A short sequence of DNA duplicated when a transposable element inserts at a new locus; usually found at each end of the insertion.
targeted drug delivery A method of delivering the activated form of a drug molecule to the site in the body where it is needed, rather than allowing it reach the target by…
Targeted mutagenesis Deliberate change in the genetic structure directed at a specific site on the chromosome. Used in research to determine the targeted region's function.
targeting vector A cloning vector carrying a DNA sequence capable of participating in a recombinational event at a specified chromosomal location in the host cell.
Task Lighting Any light source designed specifically to direct light a task or work performed by a person or machine.
TATA box An adenine- and thymine-rich promoter sequence located 25-30 bp upstream of a gene, which is the binding site of RNA polymerase.
tautomeric shift The transfer of a hydrogen atom from one position in an organic molecule to another position.
tautomerism A type of isomerism in which the two isomers arising from a tautomeric shift are in equilibrium.
Tax Increment Financing A program designed to leverage private investment for economic development projects in a manner that enhances the benefits accrued to the public interest.
Taxonomy The science of categorization, or classification, of things based on a predetermined system.
TCU Towering cumulus clouds
TD -- see terminal disclaimer
TDA Today
TDWR Terminal Doppler Weather Radar
TEA transverse-excited atmospheric pressure
Technical Response Service For assistance with technical questions about alternative fuels and advanced vehicles, email the Technical Response Service at technicalresponse@icfi.
Technology transfer The process of providing the private sector access to technological advances developed by scientists in the Federal government. See also
Tectonic Refers to the rock-deforming processes and resulting structures that occur over large sections of the lithosphere.
Tectonics The science that deals with the structure of the earth's crust.
Tee A pipe fitting that has two threaded openings in line, and a third at right angles to them.
Teleconnection Linkage between changes in atmospheric circulation occurring in widely separated parts of the globe.
Telescope To slide one piece inside another.