| FLV | feline leukemia virus; Friend leukemia virus |
|---|---|
| ARFC | active rosette-forming T-cell; autologous rosette-forming cell |
| CFC | capillary filtration coefficient; colony-forming capacity; cardiofaciocutaneous [syndrome]; chlorofl... |
| PFU | plaque-forming unit; pock-forming unit |
| FDV | Friend disease virus |
| condenser, variable-focus | <microscopy> Essentially an Abbe condenser in which the upper lens element is fixed and the lower movable. The lower lens may be used to focus the illumination between the elements so that it emerges from the stationary lens as a large diameter parallel bundle. The field of low-power objectives may thus be filled without removing the top element. at the opposite extreme it can be adjusted to have a numerical aperture as high as 1.3. See: illumination, critical. (05 Aug 1998) |
|---|---|
| principal focus | The real or virtual meeting point of rays passing into a lens parallel to its axis. (05 Mar 2000) |
| natural focus of infection | An ecosystem in which an infectious agent normally persists in nature; e.g., yellow fever virus in a jungle monkey-Haemagogus mosquito ecosystem. (05 Mar 2000) |
| depth of focus | <microscopy> The depth or thickness of the image space that is simultaneously in acceptable focus. The range of distances between a lens and image plane (target in the video pickup device) for which the image formed by the lens at a given setting is clearly focused. With a high-numerical aperture microscope objective, the depth of field is very shallow, but the depth of focus can be quite deep and reach several millimetres. (05 Aug 1998) |
| focus | Group of (frequently neoplastic) cells, identifiable by distinctive morphology or histology. (18 Nov 1997) |
| focus groups | A method of data collection and a qualitative research tool in which a small group of individuals are brought together and allowed to interact in a discussion of their opinions about topics, issues, or questions. (12 Dec 1998) |
| focus, principal | <physics> The point at which a lens focuses an axial object point. Synonymous with focal point. (05 Aug 1998) |
| antibody-forming cell | <immunology> B-cells (plasma cells) that are dedicated to producing secreted antibodies. (09 Feb 1998) |
| burst forming unit | <haematology> A bone marrow stem cell lineage detected in culture by its mitotic response to erythropoietin and subsequent erythrocytic differentiation in about 12 mitotic cycles into erythrocytes. (18 Nov 1997) |
| maltotriose-forming amylase | <enzyme> Also carries out transglycosylation, forming p-nitrophenyl alpha-maltotetraoside from maltotetraose and p-nitrophenyl alpha-d-glucopyranoside Registry number: EC 3.2.1.- Synonym: g3-amylase (26 Jun 1999) |
| channel forming ionophore | <chemistry> An ionophore that makes an amphipathic pore with hydrophobic exterior and hydrophilic interior. most known types are cation selective. (18 Nov 1997) |
| gram-positive endospore-forming bacteria | <microbiology> Bacteria that form endospores and are gram-positive. Representative genera include bacillus, clostridium, micromonospora, saccharopolyspora, and streptomyces. (12 Dec 1998) |
| gram-positive endospore-forming rods | <microbiology> Rod-shaped bacteria that form endospores and are gram-positive. Representative genera include bacillus and clostridium. (12 Dec 1998) |
| rosette-forming cells | T lymphocytes with an affinity for sheep erythrocytes and which, when suspended in serum, bind the uncoated, nonsensitised erythrocytes in a rosette formation. (05 Mar 2000) |
| colony-forming unit | <cell biology> An individual cell which is able to clone itself into an entire colony of identical cells. Irradiated mice can have their immune systems reconstituted by the injection of bone marrow cells from a nonirradiated animal. The injected cells form colonies in the spleen (hence s), each colony representing the progeny of a pluripotent stem cell. Operationally, therefore, the number of colony-forming units is a measure of the number of stem cells. Acronym: CFU (09 Oct 1997) |