| COS cell | <cell culture> A cell line derived from the african green monkey and used for transfection and cloning. The cells are simian fibroblasts (CV 1 cells) transformed by SV40 that is deficient in the origin of replication region. They express large T antigen constitutively and if transfected with a vector containing a normal SV40 origin have all the other early viral genes necessary to generate multiple copies of the vector and thus to give very high levels of expression. (04 Jul 1999) |
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| cos site | <molecular biology> A 12-nucleotide bases-long segment of single stranded DNA that exists at both ends of the bacteriophage lambda's double-stranded genome. The two cos sites at the ends of the genome are complementary to one another so that the genome can become circular once the virus has infected a host bacterium. The circular genome can then be duplicated continuously until there are many repeats of it strung together, the cos sites show the virus where to cut them apart right before they are packaged into individual capsids as new progeny viruses ready to infect more host cells. (10 Nov 1998) |
| cosmesis | <surgery> A concern in therapeutics, especially in surgical operations, for the appearance of the patient; i.e., a resort to an operation which will improve the appearance. Origin: G. Kosmesis, an adorning, fr. Kosmeo, to order, arrange, adorn, fr. Kosmos, order (05 Mar 2000) |
| cosmetic | <chemistry> A substances intended to be applied to the human body for cleansing, beautifying, promoting attractiveness, or altering the appearance without affecting the body's structure or functions. Included in this definition are skin creams, lotions, perfumes, lipsticks, fingernail polishes, eye and facial makeup preparations, permanent waves, hair colours, toothpastes, and deodorants, as well as any material intended for use as a component of a cosmetic product. Origin: Gr. Kosmetikos (04 Jul 1999) |
| cosmetic dermatitis | <dermatology> A cutaneous eruption that results from the application of a cosmetic; due to allergic sensitization or primary irritation. (05 Mar 2000) |
| cosmetic surgery | <surgery> Surgery in which the principal purpose is to improve the appearance, usually with the connotation that the improvement sought is beyond the normal appearance, and its acceptable variations, for the age and the ethnic origin of the patient. Synonym: esthetic surgery. (05 Mar 2000) |
| cosmetic techniques | <surgery> Procedures for the improvement or enhancement of the appearance of the visible parts of the body. (12 Dec 1998) |
| cosmetics | Composite term for a variety of camouflages applied to the skin, lips, hair, and nails for purposes of beautifying in accordance with cultural dictates. (05 Mar 2000) |
| cosmic dust | <astronomy> Finely divided solid matter with particle sizes smaller than a micrometeorite, thus with diameters much smaller than a millimeter, moving in interplanetary space. (12 Dec 1998) |
| cosmic radiation | <radiobiology> High-energy radiation or particles from extraterrestrial space that strike the earth, its atmosphere, or spacecraft and may create secondary radiation as a result of collisions with the atmosphere or spacecraft. (12 Dec 1998) |
| cosmic rays | <radiobiology> High velocity particles of enormous energies, bombarding earth from outer space. It consists of protons and more complex atomic nuclei that, on striking the atmosphere, give rise to neutrons, mesons, and other less energetic radiation. (05 Mar 2000) |
| cosmid | <molecular biology> An artificially constructed type of bacteriophage lambda cloning vector containing the cos gene of phage lambda. Cosmids can be packaged in lambda phage particles for infection into E. Coli, this permits cloning of larger DNA fragments (up to 45 kb) than can be introduced into bacterial hosts in plasmid vectors. They are used as cloning vehicles for the study of aberrant eukaryotic structural genes and also as genetic vectors for introducing the nucleic acid of transforming viruses into cultured cells. Often used for construction of genomic libraries, because of their ability to carry relatively long pieces of DNA insert, compared with plasmids. (04 Jul 1999) |
| cosmid map | <molecular biology> A physical map that includes a collection of bacteria containing cosmids that carry the DNA fragments under study. (10 Nov 1998) |
| cosmopolitan | In the biological sciences, a term denoting worldwide distribution. Origin: G. Kosmos, universe, + polis, city-state (05 Mar 2000) |
| cost allocation | The assignment, to each of several particular cost-centres, of an equitable proportion of the costs of activities that serve all of them. Cost-centre usually refers to institutional departments or services. (12 Dec 1998) |
| Hippocrates of Cos | Greek physician, called the "Father of Medicine," circa 460-377 B.C. See: hippocratic facies, hippocratic fingers, hippocratic nails, school, succussion. (05 Mar 2000) |
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