Normal human diploid cells, TIG-1, ceased to proliferate at about the 62 population doubling level (PDL). Transformed clones isolated from TIG-1 cells infected with wtSV40 and those with tsA900 SV40 cultured at 34 degrees C were subcultured up to about 80 PDL. When the culture temperature of tsA SV40-transformed cells was shifted from 34 to 39.5 degrees C at 51 PDL, the growth curve of these transformed cells changed to that of normal young cells.
Hormesis, the beneficial effect of a mild stress, has been proposed as a means to prolong the period of healthy ageing as it can increase the average lifespan of a cohort. However, if we want to use hormesis therapeutically it is important that the treatment is beneficial on the individual level and not just on average at the population level. Long lived lines have been shown not to benefit from a, in other lines, hormesis inducing heat treatment in Drosophila melanogaster, D. buzzatii and mice.
Nihon Ronen Igakkai Zasshi. Japanese Journal of Geriatrics
To explore factors associated with longevity, we studied geographic distribution of centenarians in Japan, based on 1990 the population census. We calculated the proportion of centenarians from ratio of number of centenarian to that of population aged 65 years or older. Centenarians in Japan consisted of number 4,152 persons. By prefecture, Tokyo had the most centenarians (383), followed by Okinawa (193) and Fukuoka (151) prefectures. Fukui had the least (24), followed by Akita (26) and Ishikawa (29) prefectures.
The clk-1 gene of the nematode Caenorhabditis elegans encodes an evolutionarily conserved enzyme that is necessary for ubiquinone biosynthesis. Loss-of-function mutations in clk-1, as well as in its mouse orthologue mclk1, increase lifespan in both organisms. In nematodes, clk-1 extends lifespan by a mechanism that is distinct from the insulin signaling-like pathway but might have similarities to calorie restriction. The evolutionary conservation of the effect of clk-1/mclk1 on lifespan suggests that the gene affects a fundamental mechanism of aging.
Laboratory study was conducted on the biology of the phorid fly Megaselia sacalaris. The influence of 3 constant temperatures and various larval densities was researched in the laboratory as these relate to mean life stage rate of development and survival. Flay development on a synthetic diet at 25 degrees C. 75=2% RH and 18 hr photophase was used as the standard. Mean times for development and survival were egg incubation 16.3 h (97.6%); larval period 7.3 days (97.6%); pupal period 9.8 days (95.8%, 91.6%); adult longevity 29.9 days, 24.8 days. Fecundity was 664.8 eggs.
This review starts by introducing the history and underlying culture of meat production and consumption in Japan since early times, and the effects of social change on these parameters. Meat processing in Japan is described, and certain other related papers are also introduced. Automatic machines for meat cutting have been developed by the Japanese food industry and are currently being used throughout the world, particularly in Europe.
BACKGROUND: The incidence of malaria in the Amazon is seasonal and mosquito vectorial capacity parameters, including abundance and longevity, depend on quantitative and qualitative aspects of the larval diet. Anopheles darlingi is a major malaria vector in the Amazon, representing >95% of total Anopheles population present in the Porto Velho region. Despite its importance in the transmission of the Plasmodium parasite, knowledge of the larval biology and ecology is limited. Studies regarding aspects of adult population ecology are more common than studies on larval ecology.