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Jake Jacobson Adrian J. Lambert Manuel Portero‐Otín Reinald Pamplona Tapiwanashe Magwere Satomi Miwa Yasmine Driege Martin D. Brand Linda Partridge 《Aging cell》2010,9(4):466-477
Low environmental temperature and dietary restriction (DR) extend lifespan in diverse organisms. In the fruit fly Drosophila, switching flies between temperatures alters the rate at which mortality subsequently increases with age but does not reverse mortality rate. In contrast, DR acts acutely to lower mortality risk; flies switched between control feeding and DR show a rapid reversal of mortality rate. Dietary restriction thus does not slow accumulation of aging‐related damage. Molecular species that track the effects of temperatures on mortality but are unaltered with switches in diet are therefore potential biomarkers of aging‐related damage. However, molecular species that switch upon instigation or withdrawal of DR are thus potential biomarkers of mechanisms underlying risk of mortality, but not of aging‐related damage. Using this approach, we assessed several commonly used biomarkers of aging‐related damage. Accumulation of fluorescent advanced glycation end products (AGEs) correlated strongly with mortality rate of flies at different temperatures but was independent of diet. Hence, fluorescent AGEs are biomarkers of aging‐related damage in flies. In contrast, five oxidized and glycated protein adducts accumulated with age, but were reversible with both temperature and diet, and are therefore not markers either of acute risk of dying or of aging‐related damage. Our approach provides a powerful method for identification of biomarkers of aging. 相似文献
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Martins Rogerio P.; Antonini Yasmine; da Silveira Fernando A.; West Stuart A. 《Behavioral ecology》1999,10(4):401-408
We carried out a field study on the life history and sex allocationof the
ground-nesting solitary bee Diadasina distincta (Hymenoptera:
Anthophoridae).This species is multivoltine, undergoing five generations a
yearbetween February and September. The numerical sex ratio of thisspecies
was female biased overall (approximately 38% males)and showed a strong and
consistent seasonal pattern. The numericalsex ratio was extremely female
biased (approximately 20% males)from February until May, and then slightly
male biased (approximately60% males) from June until September. Females were
3.26 timesthe size of males, and so the overall investment ratio was female
biasedthroughout the year. The overall female bias and seasonal variationin
sex allocation is unlikely to be explained by models thatinvoke overlapping
generations or competition between brothersfor mates (local mate
competition). We suggest that a possibleexplanation for the female bias in
the early part of the seasonis local resource enhancement (LRE): nesting near
larger numbersof sisters reduces parasitism. LRE is likely to decrease in
importancein the later part of the season, when the biased numerical and
investmentratios may be explained by models in which male and female
offspringgain different fitness returns from resources invested. 相似文献