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Age-related Variation (age-related + variation)
Selected AbstractsAge-related variation in the presentation of childhood stroke varies with inclusion criteriaACTA PAEDIATRICA, Issue 1 2010Meredith R Golomb No abstract is available for this article. [source] Age-related variation in the presentation of childhood stroke varies with inclusion criteria: Author's replyACTA PAEDIATRICA, Issue 1 2010Francesca Del Balzo No abstract is available for this article. [source] Age-related variations and sex differences in gender cleavage during middle childhoodPERSONAL RELATIONSHIPS, Issue 2 2001ROSANNE BURTON SMITH Gender cleavage, the segregation of the sexes, is a powerful phenomenon affecting socialization during childhood, but its developmental trajectory is far from clear. Sociometric responses by 299 boys and girls in Grades 3 to 6 from a group preference record were used to investigate age-related variations and sex differences in gender cleavage. Moreno's (1953) developmental model of gender cleavage was examined in the light of sociocultural changes, as well as advances in the theory and measurement of gender cleavage. Sex differences were found in same-gender preference, with older elementary girls showing greater same-gender preference than boys of the same age. However, this finding, plus the absence of gender differences in cross-gender evaluations, did not support more recent developmental accounts of gender cleavage. Linear trend analyses contradicted Moreno's basic precept of increasing same-gender preference between Grades 3 and 6. While same-gender acceptance and rejection were relatively similar regardless of grade level, cross-gender acceptance was greater in higher than in lower grades and the reverse was true for rejection. Furthermore, weaker gender cleavage effects in rejection data than in acceptance data suggested that strong same-gender liking does not infer equally robust cross-gender dislike. Gender cleavage appears to be relative rather than absolute. A more complex model is proposed incorporating sex differences as well as rejection evaluations [source] Variations of Somatotype in elderly SardiniansAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 4 2005R. Buffa Somatotyping is an effective technique for the study of anthropometric variations and body composition in elderly subjects, even though it has not often been used in this field. The present study was conducted on a sample of 280 healthy Sardinians (134 men and 146 women) of age 60,89 years, subdivided into three age classes (60,69 years; 70,79 years; and 80,89 years). Somatotypes were computed according to Carter and Heath (Somatotyping,Development and Applications. Cambridge, England: Cambridge University Press; 1990). The results show a dominance of the endo- and mesomorphic components in the elderly subjects, with less development of ectomorphy than in younger individuals. In a comparison with other populations, our sample shows strong development of endomorphy and especially of mesomorphy, while ectomorphy values are generally low. Age-related variations are significant in both sexes and consist in a progressive reduction of the endomorphic component, particularly in the 80,89-year class (endomorphy in the three age classes: 6.4, 6.1, and 5.3 in men; 8.1, 7.8, and 6.8 in women). The mesomorphic component is characterized by stability (age variations: 6.4, 6.4, and 5.9 in men; 6.3, 6.4, and 6.3 in women) and the ectomorphic component by a slight increase (age variations: 0.5, 0.6, and 0.8 in men; 0.4, 0.3, and 0.5 in women). Sex differences are significant and especially large for the endomorphic component, with generally higher values in women. The sexual dimorphism tends to decrease with age. The results are discussed with regard to the biology of aging, with emphasis on the potential application of somatotype to studies of the elderly population. Am. J. Hum. Biol. 17:403,411, 2005. © 2005 Wiley-Liss, Inc. [source] Circadian variation in salivary testosterone across age classes in Ache Amerindian males of ParaguayAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 2 2010Richard G. Bribiescas Testosterone levels exhibit a circadian rhythm in healthy men, with morning levels tending to be higher compared to evening titers. However, circadian rhythms wane with age. Although this has been described in males living within industrialized settings, age-related changes have not received similar attention in populations outside these contexts. Because many nonindustrialized populations, such as Ache Amerindians of Paraguay, exhibit testosterone levels that are lower than what is commonly reported in the clinical literature and lack age-associated variation in testosterone, it was hypothesized that Ache men would not show age-related variation in testosterone circadian rhythms. Diurnal rhythmicity in testosterone within and between Ache men in association with age (n = 52; age range, 18,64) was therefore examined. A significant negative association was evident between the ratio of morning and evening salivary testosterone and age (r = ,0.28, P = 0.04). Men in their third decade of life exhibited significant diurnal variation (P = 0.0003), whereas older and younger age classes did not. Men between the ages of 30 and 39 also exhibited a higher AM:PM testosterone ratio compared to 40,49 and 50< year old men (P = 0.002, 0.006). Overall, declines in testosterone with aging may not be universal among human males, however, within-individual analyses of diurnal variation capture age-related contrasts in daily testosterone fluctuations. Circadian rhythmicity differs with age among the Ache and may be a common aspect of reproductive senescence among men regardless of ecological context. Am. J. Hum. Biol., 2010. © 2009 Wiley-Liss, Inc. [source] Blood pressure, seasonal body fat, heart rate, and ecological differences in Caboclo populations of the Brazilian AmazonAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 1 2006H.P. Silva This study compares blood pressure (BP) and related cardiovascular risk factors among three Caboclo communities from the Brazilian Amazon. Its purpose is to investigate possible risk differentials related to variable ecological settings and Western influences. Caxiuanã is characterized as a more "traditional" group, while Aracampina and Santana are viewed as more "transitional" in lifestyle. A total of 348 subjects from the three communities were evaluated in the wet or the dry season or in both. Measurements across the communities were compared by season and sex. Results suggest little seasonal variation in average BP, BP change, body fat, or body fat change among men. Conversely, there is substantial seasonal and intercommunity variation among women. Additional analyses reveal (1) an inconsistent association between age and BP across the communities; (2) that BMI is not associated with BP transitional communities in either season but is associated with both systolic and diastolic pressure in the most traditional community; and (3) little to no sex effect on BP. These results suggest increased Western influence affects body composition particularly of women. However, increased BMI and fat among transitional Caboclo women does not directly translate into higher BP; rather, their BP appears to be more affected by seasonal stresses. Finally, conditions during the wet season diminish age-related variation in BP, suggesting that during the wet season these Caboclo may be less active. Am. J. Hum. Biol. 18:10,22, 2006. © 2005 Wiley-Liss, Inc. [source] Isotopic evidence for age-related variation in diet from Isola Sacra, ItalyAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2005Tracy L. Prowse Abstract This study examines collagen (N = 105) and apatite (N = 65) data from an Imperial Roman skeletal sample from the necropolis of Isola Sacra (Rome, Italy). This paper explores correlations between the isotopic composition of bone samples and the inferred age and sex of these individuals (aged 5,45+ years). The collagen of males, and older individuals in general, was significantly enriched in 15N but not 13C. Bone carbonate was somewhat depleted in 13C in some older individuals, suggesting increased consumption of olive oil and possibly wine. Subadults (>5 years) in the sample appear to have consumed an almost exclusively terrestrial diet. This study demonstrates a clear trend in dietary patterns between adult age groups, as well as between adults and children within a population. Am J Phys Anthropol 128:2-13, 2005. © 2005 Wiley-Liss, Inc. [source] Diminished contraction-induced intracellular signaling towards mitochondrial biogenesis in aged skeletal muscleAGING CELL, Issue 4 2009Vladimir Ljubicic Summary The intent of this study was to determine whether aging affects signaling pathways involved in mitochondrial biogenesis in response to a single bout of contractile activity. Acute stimulation (1 Hz, 5 min) of the tibialis anterior (TA) resulted in a greater rate of fatigue in old (36 month), compared to young (6 month) F344XBN rats, which was associated with reduced ATP synthesis and a lower mitochondrial volume. To investigate fiber type-specific signaling, the TA was sectioned into red (RTA) and white (WTA) portions, possessing two- to 2.5-fold differences in mitochondrial content. The expression and contraction-mediated phosphorylation of p38, MKK3/6, CaMKII and AMPK, were assessed. Kinase protein expression tended to be higher in fiber sections with lower mitochondrial content, such as the WTA, relative to the RTA muscle, and this was exaggerated in tissues from senescent, compared to young animals. At rest, kinase activation was generally similar between young and old animals, despite the age-related variations in mitochondrial volume. In response to contractile activity, age did not influence the signaling of these kinases in the high-oxidative RTA muscle. However, in the low-oxidative WTA muscle, contraction-induced kinase activation was attenuated in old animals, despite the greater metabolic stress imposed by contractile activity in this muscle. Thus, the reduction of contraction-evoked kinase phosphorylation in muscle from old animals is fiber type-specific, and depends on factors which are, in part, independent of the metabolic milieu within the contracting fibers. These findings imply that the downstream consequences of kinase signaling are reduced in aging muscle. [source] Age-related variations and sex differences in gender cleavage during middle childhoodPERSONAL RELATIONSHIPS, Issue 2 2001ROSANNE BURTON SMITH Gender cleavage, the segregation of the sexes, is a powerful phenomenon affecting socialization during childhood, but its developmental trajectory is far from clear. Sociometric responses by 299 boys and girls in Grades 3 to 6 from a group preference record were used to investigate age-related variations and sex differences in gender cleavage. Moreno's (1953) developmental model of gender cleavage was examined in the light of sociocultural changes, as well as advances in the theory and measurement of gender cleavage. Sex differences were found in same-gender preference, with older elementary girls showing greater same-gender preference than boys of the same age. However, this finding, plus the absence of gender differences in cross-gender evaluations, did not support more recent developmental accounts of gender cleavage. Linear trend analyses contradicted Moreno's basic precept of increasing same-gender preference between Grades 3 and 6. While same-gender acceptance and rejection were relatively similar regardless of grade level, cross-gender acceptance was greater in higher than in lower grades and the reverse was true for rejection. Furthermore, weaker gender cleavage effects in rejection data than in acceptance data suggested that strong same-gender liking does not infer equally robust cross-gender dislike. Gender cleavage appears to be relative rather than absolute. A more complex model is proposed incorporating sex differences as well as rejection evaluations [source] | ||||||||||