Abbreviation used on long-term climate outlooks issued by CPC to indicate areas that are likely to be below normal for a given parameter (temperature, precipitation, etc.).
- Browse Related Terms: A, B, CL, Climate Diagnostics Bulletin, Climatological Outlook, Drought Assessments, ENSO Diagnostic Discussion, Hazards Assessment, OTLK, PWO, SWODY2
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An important class of lymphocytes that mature in bone marrow (in mammals) and the Bursa of Fabricius (in birds) and produce antibodies. Largely responsible for the antibody-mediated or humoral immune response, giving rise to the antibody-producing plasma cells and some other cells of the immune system. Synonym: B lymphocyte.
- Browse Related Terms: adoptive immunization, allergen, antibody-mediated immune response, auto-immune disease, auto-immunity, B cell, cell-mediated (cellular) immune response, clonal selection, effector cells, humoral immune response, immune response, immunization, immunogenicity, immunoprophylaxis, immunosuppressor, Interleukin, lymphokine, major histocompatibility antigen, memory cell, monokine, multivalent vaccine, passive immunity, phagocytes, primary immune response, secondary immune response, T cell, T-cell-mediated (cellular) immune response, universal donor cell, vaccination
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Also known as B lymphocytes. Each B cell is capable of making one specific antibody. When stimulated by antigen and helper T cells, B cells mature into plasma cells that secrete large amounts of their specific antibody.
- Browse Related Terms: antibody, Antibody (Immunoglobulin), antigen, Autoantibody, autoimmune disease, B cells, Fluorescence-activated cell sorting (FACS), hybridoma, Immunofluorescence, Lineage surface antigen (Lin), Surface marker, Surface markers
A supernumerary chromosome present in some individuals (both plant and animal). They are smaller than the normal chromosomes, behave abnormally in both mitosis and meiosis, can vary in number between somatic cells and are not thought to have any significant gene content.
- Browse Related Terms: B chromosome, Chimera, consanguinity, endopolyploidy, graft hybrid, heredity, lineage, pedigree, proband, sport, strain, transgenic
See: B cell.
- Browse Related Terms: asexual embryogenesis, B lymphocyte, Colony, corpus, cytolysis, cytotoxic T cell, cytotoxicity, DNA micro-array, Instability, intracellular, metabolic cell, mutagenesis, myeloma, nucleo-cytoplasmic ratio, organized tissue, PCV, plant cell culture, sieve element, single-cell line, somatic cell variant, somatic reduction, stomatal complex, syncytium, T lymphocyte, tumor suppressor gene
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A Weather Service form documenting station management, exposure, topography, driving instructions, payment information, hydrometeorologic equipment, and observing information.
- Browse Related Terms: ASOS, B-44 Form, Cooperative Station Report, Climate, Congressional Organic Act of 1890, County Warning Forecast Area (CWFA), Hydrologic Service Area (HSA), Hydrologic Services, Hydrometeorological Report (HMR), Mission of the National Weather Service, National Interagency Fire Center (NIFC), National Weather Service (NWS), Regional Operations Manual Letter (ROML), Warning stage, Weather Forecast Office (WFO)
Abbreviation for bacterial artificial chromosome.
- Browse Related Terms: BAC, chromosome aberration, HAC, human artificial chromosome, mega yeast artificial chromosome, semi-sterility, YAC
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(Abbreviation: Bt). A bacterium that produces a toxin against certain insects, particularly Coloeoptera and Lepidoptera; a major means of insecticide for organic farming. Some of the toxin genes are important for transgenic approaches to crop protection.
- Browse Related Terms: anti-idiotype antibody, Bacillus thuringiensis, exogenous DNA, gene gun, genetically modified organism, microprojectile bombardment, Reporter gene, transgene
A bacterium that kills insects; a major component of the microbial pesticide industry.
- Browse Related Terms: acaricide, Bacillus thuringiensis (Bt), bio-accumulation, Cry1A, Environmental Protection Agency (EPA), Fungicide, insecticide, LD50, open pollination, persistent, Pesticide, Resistance management
A thunderstorm in which new development takes place on the upwind side (usually the west or southwest side), such that the storm seems to remain stationary or propagate in a backward direction.
- Browse Related Terms: Avalanche Advisory, Back-building Thunderstorm, BRN, Bulk Richardson Number, CSI, Dry Line Storm, DVLP, Energy Helicity Index, EXTRM, Loaded Gun (Sounding), Symmetric Double Eye, T Rolls, Tilted Storm, Tilted Updraft, Transverse Bands, Transverse Rolls
A cold front moving south or southwest along the Atlantic seaboard and Great Lakes; these are especially common during the spring months.
- Browse Related Terms: Arctic front, Back Door Cold Front, Bubble High, CDFNT, Dew Point Front, Dynamic Lifting, Extratropical Cyclone, FNT, Outflow Boundary, Potential Vorticity, Pre-Frontal Squall Line, TROP, Tropopause Jet
- Browse Related Terms: amorph, back mutation, cis heterozygote, cryptic, Darwinian cloning, Deletion, down promoter mutation, genetic disease, hemophilia, heteroallele, hypomorph, Irradiation, mutable gene, Mutation, mutation pressure, neutral mutation, neutral theory, Point mutation, Recessive gene, silent mutation, Site-directed mutagenesis, somatic hypermutation, spontaneous mutation, trans heterozygote, X-linked disease
A pressure that can cause water to backflow into the water supply when a user's water system is at a higher pressure than the public water system.
- Browse Related Terms: ASCC, AVADS, back pressure, Baseload plant, Control area, Coordinated operation, Coordination, Distribution system, Grid, Independent System Operator (ISO), Interconnected system, Interruptible demands, Interruptible load, Open access same-time information system (OASIS), Operational waste, Operations and maintenance costs, Parallel path flow, Power pool, Resilience, Standby reserves, Tie lines, Voltage reduction, Western Area Power Administration (WAPA)
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[Slang], a thunderstorm anvil which spreads upwind, against the flow aloft. A back-sheared anvil often implies a very strong updraft and a high severe weather potential.
- Browse Related Terms: Anvil, Anvil Crawler, Anvil Zits, Back-sheared Anvil, Blue Watch or Blue Box, Cumuliform Anvil, Knuckles, Mammatus Clouds, Mushroom, Orphan Anvil, Positive Cloud to Ground Lightning, Spin-Up, SPRD, Vort Max, Wildfire