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Age-dependent Patterns (age-dependent + pattern)
Selected AbstractsThe effect of parental acclimation to spawning salinity on the survival of larval Cynoscion nebulosusJOURNAL OF FISH BIOLOGY, Issue 3 2002C. J. Kucera The yolk and oil depletion of eggs and larvae of spotted seatrout Cynoscion nebulosus, produced by fish collected from two bays with historically different salinity regimes (Matagorda Bay (MB; 18-24%) and Upper Laguna Madre (ULM; 40,50%), Texas, U.S.A. and spawned in salinities of 20, 30 and 40%, differed in their response to both salinity and history. Time to 90% yolk depletion was significantly longer for low salinity bay fish (MB) kept at 20%, but not for high salinity bay fish (ULM) at 20%. The neutral buoyancy salinity of 1 and 2 day old MB 20% larvae was significantly lower than that of MB larvae spawned in 30 or 40%. Overall, eggs and larvae spawned by MB fish were able to hatch out and survive to 3 days post-hatch in lower salinities than those from ULM. Furthermore, the tolerance of eggs and larvae to very low salinities increased with decreasing spawning salinity. The ability of 1,9 day old ULM, but not MB, larvae to survive 18 h exposure to salinities above or below that of spawning exhibited an age-dependent pattern with day 3 being the most sensitive. This study shows that the response of spotted seatrout eggs and larvae to changes in salinity is dependent upon the spawning salinity of the adults and the prevailing salinity regime within the bay. [source] Different roles of natural and sexual selection on senescence of plumage colour in the barn swallowFUNCTIONAL ECOLOGY, Issue 2 2009Ismael Galván Summary 1Colour may show effects of senescence because the pigment or structures involved in production of colouration deteriorate with age. 2We tested this hypothesis by investigating age-related changes in plumage colour for two feather tracts coloured by eumelanin or pheomelanin in a longitudinal study of a cohort of barn swallows Hirundo rustica that reached very old age (at least 5 years). 3The level of melanization of the throat increased with age in both sexes, but particularly in females. In contrast, the black colour of the plumage of the back was unrelated to age in both sexes. 4These age-dependent patterns of colouration of different feather tracts of male and female barn swallows suggest that effects of senescence are trait-specific depending on their importance in sexual signalling. The red throat colour based on pheomelanin is involved in sexual selection, with a strong effect in males, but not in females. In contrast, the black colour of the back based on eumelanin is unrelated to sexual selection, but is under natural selection due to intense abrasion of this feather tract. 5These findings suggest that the relative importance of natural and sexual selection are important determinants of the pattern and rate of senescence of colour. [source] Incidence of Dementia, Alzheimer's Disease, and Vascular Dementia in Italy.JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 1 2002The ILSA Study OBJECTIVES: To estimate the incidence of dementia, Alzheimer's disease (AD), and vascular dementia (VaD) in older Italians and evaluate the relationship of age, gender, and education to developing dementia. DESIGN: Cohort incidence study in the context of the Italian Longitudinal Study on Aging. SETTING: Population sample from eight Italian municipalities. PARTICIPANTS: A dementia-free cohort of 3,208 individuals (aged 65,84), individuated after a baseline evaluation performed in 1992 / 93, aimed at detecting prevalent cases. MEASUREMENTS: The dementia-free cohort was reexamined in 1995 to identify incident cases. The Mini-Mental State Examination (cutoff 23 / 24) was employed to screen for dementia. Trained neurologists evaluated the individuals who screened positive. Final diagnoses had to meet Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised criteria for dementia, National Institute of Neurological and Communicative Disorders and Stroke,Alzheimer's Disease and Related Disorders Association criteria for AD, and International Classification of Diseases, Tenth Revision criteria for VaD. RESULTS: Before the follow-up examination, 382 individuals had died (232 had reliable information). Of the 2,826 survivors, 2,266 completed the study. Overall, 127 new dementia cases were identified. Average incidence rates per 1,000 person-years were 12.47 (95% confidence interval (CI) = 10.23,14.72) for dementia, 6.55 (95% CI = 4.92,8.17) for AD, and 3.30 (95% CI = 2.14,4.45) for VaD. Both AD and VaD showed age-dependent patterns. Education was protective against dementia and AD. Women carried a significantly higher risk of developing AD (hazard ratio = 1.67, 95% CI = 1.02,2.75), and men of developing VaD (hazard ratio = 2.23, 95% CI = 1.06,4.71). CONCLUSIONS: Incidence of dementia in Italy paralleled that in most industrialized countries. About 150,000 new cases per year are expected. A significant gender effect was evidenced for major dementia subtypes. The burden of VaD, especially in men, offers opportunities for prevention. [source] Inconsistent determination of overweight by two anthropometric indices in girls with Turner syndromeACTA PAEDIATRICA, Issue 3 2009Tsuyoshi Isojima Abstract Aim: To evaluate the prevalence of overweight in girls with Turner syndrome (TS) as classified by the two major anthropometric indices, body mass index (BMI) and weight-for-height (WFH) and to make growth reference charts of them for comparison with those of the normal population. Method: The samples for analysis were obtained from a retrospective cohort. In total, 1447 girls' cross-sectional data were analysed. Subjects were divided into four groups by ages: group A (0,5.99 years), B (6,10.99 years), C (11,15.99 years) and D (16,20.99 years). The cut-off values of overweight by BMI and WFH were those of the 90th percentile and 120 percent, respectively and the prevalence was calculated. For constructing growth reference charts, the LMS method was used. Results: The prevalence of overweight differed between the two indices. The proportions of the coincidental classification in all subjects, group A, B, C and D were 82.53%, 89.96%, 91.79%, 69.98% and 60.61%, respectively. These differences corresponded to the difference of age-dependent patterns of the two indices from those of the normal population, as judged from the growth charts constructed with all subjects. Conclusion: A discrepancy in the prevalence of overweight as classified by BMI and WFH for girls with TS was detected. [source] | ||||||||||