The impact factor of journal provides quantitative assessment tool for grading, evaluating, sorting and comparing journals of similar kind. It reflects the average number of citations to recent articles published in science and social science journals in a particular year or period, and is frequently used as a proxy for the relative importance of a journal within its field. It is first devised by Eugene Garfield, the founder of the Institute for Scientific Information. The impact factor of a journal is evaluated by dividing the number of current year citations to the source items published in that journal during the previous two years.
Apoptosis is the process of programmed cell death which usually occur in multicellular organisms and the biochemical events lead to characteristic cell changes (morphology) and then death. These changes include cell chromosomal DNA fragmentation, shrinkage, nuclear fragmentation, blebbing and chromatin condensation. Apoptosis is death of a cell in any form, mediated by an intracellular program. Apotosis is carried out in a regulated process that normally confers advantage during an organism's life-cycle. In a developmental context cells are induced to positively commit suicide while in a homeostatic context the absence of certain survival factors may provide the impetus for suicide. There appears to be some variety in the morphology and indeed the biochemistry of these suicide routeways; some treading the route of "apoptosis", others following a more generalized pathway to deletion, but both usually being genetically and synthetically inspired. There is some evidence that certain symptoms of "apoptosis" such as endonuclease activation can be spuriously induced without engaging a genetic cascade, although, most likely true apoptosis and programmed cell death should be genetically mediated. It is furthermore evolving clear that mitosis and apoptosis are toggled or connected in some way and that the balance achieved counts on pointers obtained from appropriate development or survival factors.
Last date updated on March, 2024