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Age-related Trends (age-related + trend)
Selected AbstractsBone weight: new reference values based on a modern Portuguese identified skeletal collectionINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 5 2009A. M. Silva Abstract Skeletal weight and/or weight of the different bones of the human skeleton are currently used in a wide range of applications such as archaeological cremations and forensics. Still, few reference values are available that compare the mean weights for the different skeletal parts. In this paper we present new reference values for total skeletal weight, including the weight of the different skeletal bones based on a modern Portuguese Identified Skeletal Collection (CEI) curated in the Museum of Anthropology of the University of Coimbra (Portugal). The mean weight of the entire skeleton for the CEI pooled sample is 3323.8,±,779.6,g. Sex and age differences were investigated. As expected, males display heavier bones, at a statistically significant level. The mean weight of the male skeletons is 3850,g, and 2797.6,g for the female sample. Age differences were found, especially for the female samples in the 29,39 versus 50,59,and/or >60 age groups, probably as a consequence of age-related bone loss in post-menopausal women. For the male sample, no clear age-related trend was observed but for the unexpected result that the second highest bone weight recorded is in the oldest age group (>60 years). This could result from high mechanical loadings and thus greater bone robusticy and amount of cortical bone. The percentage of weight of the different parts of the skeleton was also calculated. These new values can be quite useful in the study of very fragmentary and/or commingled human remains, recovered from historic or forensic contexts, since the complete identification, by side, of the remains is not necessary. Copyright © 2008 John Wiley & Sons, Ltd. [source] Frequency of loss of hMLH1 expression in colorectal carcinoma increases with advancing age,CANCER, Issue 6 2003Sanjay Kakar M.D. Abstract BACKGROUND The correlation between age at diagnosis and loss of expression of hMLH1 protein in patients with colorectal carcinoma (CRC) has not been evaluated systematically. METHODS Immunohistochemistry was performed for hMLH1 protein in tumor samples from 867 patients with CRC. The authors defined tumors arising in the cecum, ascending colon, and transverse colon as right-sided and tumors arising in the descending colon, sigmoid colon, and rectum as left-sided. Patients' gender, tumor location (side), and hMLH1 expression were analyzed by age groups. RESULTS The percentage of tumors with hMLH1 expression loss increased significantly with advancing age (P < 0.0001): There were no tumors in patients age < 40 years that manifested loss of hMLH1 expression, compared with 29% of tumors that manifested loss of hMLH1 expression in patients age > 90 years. Loss of hMLH1 expression occurred more often in patients with right-sided tumors (32.7% vs. 5.2% of patients with left-sided tumors; P < 0.0001) and in tumors from female patients (24.3% vs. 11.5% of tumors from male patients; P < 0.0001). There was no evidence of interaction between gender and tumor location. CONCLUSIONS Loss of hMLH1 expression in patients with CRC was associated strongly with increasing age. hMLH1 expression loss was more pronounced in tumors from female patients and in tumors that originated on the right side of the colon. Loss of hMLH1 expression in right-sided tumors occurred in nearly 50% of patients age > 90 years. This age-related trend also was observed for males and in tumors that originated in the left colon. Cancer 2003;97:1421,7. © 2003 American Cancer Society. DOI 10.1002/cncr.11206 [source] Individual trajectories of substance use in lesbian, gay and bisexual youth and heterosexual youthADDICTION, Issue 6 2009Michael P. Marshal ABSTRACT Aims Several decades of research have shown that lesbian, gay and bisexual (LGB) adults are at high risk for substance use and substance use disorders, and a recent meta-analysis shows that these disparities most probably begin in adolescence; however, no studies to date have examined longitudinal growth in substance use in LGB youth and heterosexual youth to determine if they follow different trajectories into young adulthood. The primary aims of this paper were to estimate individual trajectories of substance use in youth and examine differences between self-identified LGB and heterosexual subsamples. Method A school-based, longitudinal study of health-related behaviors of adolescents and their outcomes in young adulthood was used to test our hypotheses (The National Longitudinal Study of Adolescent Health). Participants were included if they were interviewed at all three waves and were not missing information regarding self-identified sexual orientation (n = 10 670). Results Latent curve models (LCMs) showed that LGB identity was associated significantly with individual variability in substance use intercepts and slopes, above and beyond age, race and gender. Self-identified LGB youth reported higher initial rates of substance use and on average their substance use increased over time more rapidly than did substance use by heterosexual youth. Two other indicators of sexual orientation (same-sex romantic attraction and same-sex sexual behavior) were also associated with substance use trajectories, and differential results were found for youth who identified as ,mostly heterosexual' and bisexual compared with youth who identified as completely heterosexual or homosexual. Conclusions Sexual orientation is an important risk marker for growth in adolescent substance use, and the disparity between LGB and heterosexual adolescents increases as they transition into young adulthood. More research is needed in order to examine: causal mechanisms, protective factors, important age-related trends (using a cohort-sequential design), the influence of gay-related developmental milestones, curvilinear effects over time and long-term health outcomes. [source] Age-dependent reproductive performance in Northern Goshawks Accipiter gentilisIBIS, Issue 1 2003Jan Tøttrup Nielsen The age-specific reproductive performance of Northern Goshawks Accipiter gentilis was studied over 22 years in Denmark. The age of the breeding female in relation to the number of young raised was known in 929 breeding attempts, while the age of both the male and the female was known in 496 breeding attempts. The number of fledglings raised per breeding attempt increased with both male and female age, but only for females was it possible to conduct a detailed analysis of this age-dependent relationship. The annual production of fledglings increased with female age from 1 to 7 years of age, whereupon it started to decline. A longitudinal analysis showed that this mean population trend could be attributed to similar age-related trends in individual females. Previous breeding experience did not influence the number of fledglings produced by individual females, and poorly performing females apparently survived with the same probability as well performing ones. The most likely explanation for the age-dependent reproductive performance in the observed Goshawk population appeared to be age-related improvements in competence, such as foraging efficiency. [source] The hypothalamus-pituitary-testis axis in boys during the first six months of life: a comparison of cryptorchidism and hypospadias cases with controlsINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 5 2009Frank H. Pierik Summary It is inconclusive whether the feedback mechanisms of the hypothalamus-pituitary-testis (HTP) axis are already established in the first 6 months of life, partly due to the dramatic changes in HPT-axis hormone levels over this period. Moreover, it is unclear whether these hormone levels are aberrant in boys with cryptorchidism or hypospadias, and therefore predictive for future fertility. We studied the regulation mechanisms of the HTP axis, and the effect of age, in boys 1,6 months of age. Secondly, we studied testicular function - as reflected by HPT hormones - in newborns with cryptorchidism or hypospadias. Sera from a population sample of infants with cryptorchidism (n = 43), hypospadias (n = 41) and controls (n = 113) were analyzed for inhibin B, anti-Müllerian hormone (AMH), testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH) and sex hormone binding globulin (SHBG). LH, testosterone, non-shbg-bound testosterone (NSBT), and AHM levels showed significant age-related trends. After age-correction, a negative correlation between FSH and inhibin B was observed (r = ,0.43). The only significant group-differences were lower testosterone and NSBT levels in cryptorchidism cases, with a mean testosterone of 1.8 and 2.6 nmol/L and a mean NSBT of 0.48 and 0.70 nmol/L for cryptorchidism cases and controls, respectively. The higher levels of LH, testosterone, and NSBT in boys born pre-term or with a low birthweight indicate that abnormal prenatal development may determine postnatal testis function. Our results support the hypothesis that the inhibin B , FSH feedback loop is already functional before puberty. The lower testosterone and NSBT levels indicate that disturbed Leydig cell function can already be detected early after birth in cryptorchid boys. [source] Estimating the effects of misleading information on witness accuracy: can experts tell jurors something they don't already know?APPLIED COGNITIVE PSYCHOLOGY, Issue 7 2007Bradley D. McAuliff This study investigated potential differences between expert and lay knowledge of factors influencing witness suggestibility. Expert psychologists (N,=,58), jurors (N,=,157), and jury-eligible undergraduates (N,=,220) estimated the effects of misleading information on witness accuracy for three age groups in various conditions. Respondents possessed similar knowledge of age-related trends in suggestibility, the positive effects of a pre-misinformation warning, and the negative influence of longer delays between the event/misinformation and event/final memory test. Compared to experts, laypeople underestimated the size of suggestibility differences between age groups and lacked knowledge about how event detail centrality, witness participation, and source prestige can increase witness suggestibility. Laypeople rated themselves as being largely unfamiliar with witness suggestibility research and thought that expert testimony would be beneficial. These data shed light on the potential helpfulness of expert testimony in cases involving witness suggestibility. Copyright © 2006 John Wiley & Sons, Ltd. [source] | ||||||||||