Rain
- Browse Related Terms: FRZN, FZRA, Ice Storm, Mixed precipitation, R, RA, Rain Gauge, ZR
All > Science > Biotechnology and Genetics > Food Biotechnology
A class of plant genes conferring resistance to a specific strain (or group of strains) of a particular pathogen. Their primary function is to sense the presence of the pathogen and to trigger the defence pathways in the plant. R genes have been cloned from a number of plant species.
- Browse Related Terms: albinism, chlorosis, cytochrome, disease-free, graft inoculation test, Immunity, inoculate, pathovar, phytopathogen, R genes, rust, source organism
All > Science > Biotechnology and Genetics > Food Biotechnology
Single-stranded DNA regions in RNA -DNA hybrids formed in vitro under conditions where RNA -DNA duplexes are more stable than DNA -DNA duplexes.
- Browse Related Terms: anneal, cot curve, Cross-hybridization, D loop, denaturing gradient gel electrophoresis, DNA hybridization, double-stranded DNA, fold-back, hairpin loop, heteroduplex analysis, Hybridization, inverted repeat, polymerase chain reaction, R-loops, renaturation, Renature, single-strand conformational polymorphism, Stringency
See R-Value.
- Browse Related Terms: Distribution Feeder, R-Factor
A measure of the capacity of a material to resist heat transfer. The R-Value is the reciprocal of the conductivity of a material (U-Value). The larger the R-Value of a material, the greater its insulating properties.
- Browse Related Terms: Active Cooling, Booster Pump, Closed Cycle, Coil, Hot Water Heating Systems, R-Value, Radiant Floor, Stirling Engine, U-Value (see Coefficient of Heat Transmission)
All > Science > Biotechnology and Genetics > Food Biotechnology
The first-generation offspring of a recombinant (genetically modified) organism. Not standard terminology. See: T0, T1, and T2.
- Browse Related Terms: attenuated vaccine, biosafety, biosafety protocol, Cartagena protocol, containment, Convention on Biological Diversity, deliberate release, Genetic engineering, genetic resources, genetically engineered organism, GEO, GM food, GMO, precautionary principle, R1
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Rain
- Browse Related Terms: FRZN, FZRA, Ice Storm, Mixed precipitation, R, RA, Rain Gauge, ZR
All > Science > Biotechnology and Genetics > Food Biotechnology
A distinguishable group of organisms of a particular species. Criteria for distinctness can be one or a combination of geographic, ecological, physiological, morphological, genetic and karyotypic factors.
- Browse Related Terms: bacterium, Germ cell (germ line) gene therapy, germ cell gene therapy, karyotype, micro-organism, microfibril, organ, RACE, trisomic
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- All > Technology > Defense
All > Science > Biotechnology and Genetics > Food Biotechnology
An inflorescence in which the main axis is elongated but the flowers are borne on pedicels that are about equal in length.
- Browse Related Terms: dicot, panicle, raceme, rachilla, receptacle, spike
All > Science > Biotechnology and Genetics > Food Biotechnology
Main axis of a spike; axis of fern leaf (frond) from which pinnae arise; in compound leaves, the extension of the petiole corresponding to the midrib of an entire leaf.
- Browse Related Terms: axillary bud, bract, cotyledon, direct embryogenesis, etiolation, lamina, leaf blade, leaf bud cutting, leaf margin, leaf primordium, leaf scar, leaflet, meristele, meristem culture, meristem tip, petiole, rachis, sporophyll, stoma, stomatal index, vitrified
All > Science > Nuclear Physics
Radiation Absorbed Dose. The basic unit of an absorbed dose of ionizing radiation. One rad is equal to the absorption of 100 ergs of radiation energy per gram of matter.
Nuclear Science Division, Lawrence Berkeley National Laboratory - Cite This Source - This Definition- Browse Related Terms: absorbed dose, becquerel, Density, dose, dose equivalent, gray, Probability, RAD, relative biological effectiveness (RBE), sievert (Sv)
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RAdar DAta Processor II, attached to some WSR-57 and WSR-74 radar units. It automatically controls the tilt sequence and computes several radar-derived quantities at regular intervals, including VIL, storm tops, accumulated rainfall, etc.
- Browse Related Terms: Algorithm, Area Wide Hydrologic Prediction System, AUTOMATIC GAIN CONTROL, HDRAIN, Precipitation Processing System, RADAP II, Radar Coded Message, Severe Weather Probability, Three-Hour Rainfall Rate, VIL, WSR-57, WSR-74
All > Science > Weather > Climate Change
An instrument useful for remote sensing of meteorological phenomena. It operates by sending radio waves and monitoring those returned by such reflecting objects as raindrops within clouds.
- Browse Related Terms: Arctic haze, Ceilometer, cloud base, cumuliform, Greenland High, Haze, infrared brightness temperature (°C), Lightning, RADAR, Southern Great Plains (SGP) site, Stratiform, thunderstorm, Tornado, Virga
Acronym for RAdio Detection And Ranging; a radio device or system for locating an object by means of ultrahigh-frequency radio waves reflected from the object and received, observed, and analyzed by the receiving part of the device in such a way that characteristics (as distance and direction) of the object may be determined.
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The straight line that a radar pulse travels along. As the radar beam gets further away from the radar, it gets wider and wider. In order for a precipitation target to be detected by the radar, it must fill the entire radar beam; therefore, the radar will have a difficult time detecting small showers and thunderstorms at a great distance from the radar.
- Browse Related Terms: Maximum Unambiguous Range, Maximum Unambiguous Velocity, Mean Doppler Velocity, Peak Pulse, Pulse, Pulse Repetition Frequency (PRF), Pulse Repetition Time (PRT), Pulse-Pair Processing, Radar Beam, Range Folding, Range Gate, Range Resolution, Receiver
This is an alphanumeric coded message which will be used in preparation of a national radar summary chart. It is automatically produced by the WSR-88D's Radar Product Generator (RPG) in 3 parts (reflectivities, storm motion, and echo tops).
- Browse Related Terms: Algorithm, Area Wide Hydrologic Prediction System, AUTOMATIC GAIN CONTROL, HDRAIN, Precipitation Processing System, RADAP II, Radar Coded Message, Severe Weather Probability, Three-Hour Rainfall Rate, VIL, WSR-57, WSR-74
The area of a fictitious, perfect reflector of electromagnetic waves (e.g., metal sphere) that would reflect the same amount of energy back to the radar as the actual target (e.g., lumpy snowflake).
- Browse Related Terms: Coherent Radar, dBZ, Echo, Ground Clutter, Minimum Discernible Signal, Monostatic Radar, Polarization Radar, Power, Pulse Radar, radar cross section, Range Normalization, Range Unfolding, Reflectivity Factor, Servo Loop, Sphere Calibration, Sun Pointing, transmitter, Z\/R Relationship
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An acronym for Radar Data Acquisition. The RDA is the hardware component of the NEXRAD system that consists of the radar antenna, transmitter, receiver, tower, and controlling computer. The RDA collects the unprocessed, analog voltages from the radar antenna and converts the signal to base reflectivity , base velocity, and spectrum width (in polar coordinate form). These "wide-band" products are transmitted to the RPG, which creates and disseminates end-user products. Also: The RDA is the origination point of the WSR-88D radar data that will be eventually used by the radar operator. This WSR-88D component group is made up of several subcomponents which generate and radiate radio frequency (RF) pulses, receive reflected energy from those pulses, and process this received energy into digital base data. The RDA is also the site of the first two of four data recording levels used by the WSR-88D to record and store radar data.
- Browse Related Terms: Hail Contamination, Hail Spike, Inch-Degrees, Partial Beam Filling, POH, Precipitation Mode, Probability of Hail, Radar Data Acquisition, Radar Mosaic, Radar Product Generator (RPG), Rainfall Estimates, SHARS, Storm Total Precipitation
All > Science > Weather > Climate Change
The power spectrum and moments of the radar signal expressed as a function of Doppler frequency or Doppler velocity. It may be thought of as the reflectivity weighted ratio velocity distribution of the scatterers in a distributed target.
- Browse Related Terms: adiabat, atmospheric turbulence, backscatter depolarization ratio, Bowen ratio, Cyclone movement, Heat balance, heat capacity, latent heat, oxygen isotope ratio (δ18O), radar doppler, Sensible heat, specific heat, Thermally Driven Circulation, Threshold, Wind Chill Factor
Branch of meteorology that uses radars for weather observations and forecasts.
- Browse Related Terms: 1-2-3 Rule, AGFS, Complex Gale/Storm, CWFA, Developing Gale/Storm, FA, FCST, FOUS, Grids, High Seas Forecast, Marine Zone, NSSFC, OFSHR, PROGGED, Radar Meteorology, RAFC, RAFS, Red Flag Warning, TAF, Valid Time, ZFP