949 research outputs found

    Reliability of AMS 14C dates of moss temper preserved in Neolithic pottery from the Scheldt river valley (Belgium)

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    Direct dates of pottery obtained from food crusts or other organic residues on the vessel surfaces can be affected by a reservoir effect and/or an old wood effect and therefore be unreliable. Hence, there is a need for alternative ways to directly date pottery. Moss is used as temper by several cultural groups of the late 6th to early 4th millennium cal BC in northwestern Europe. After the pottery is fired, charred moss remains are often preserved in the clay, so that relatively short-lived plant material with a direct chronological link to the pottery and human occupation is available for radiocarbon (C-14) dating. In this study, charred moss temper is extracted for accelerator mass spectrometry (AMS) C-14 dating from pottery of the Swifterbant Culture and Spiere group in the Scheldt river valley (Belgium). The moss dates are then compared to reference dates of organic macro-remains from the same sites and food crust dates with or without a reservoir effect of the same pottery. Eleven out of 13 moss dates are in line with the expected pottery age. The paired dates of moss temper and food crusts from the same potsherds confirm a freshwater reservoir effect (FRE) for the latter. We conclude that moss temper has great potential as a sample material for direct pottery dating. However, more research on the extraction and pretreatment of moss temper as well as on the reliability of moss dates is necessary in the future

    Cross-sectional and longitudinal study of bone mineral status of older men

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    Longitudinal analysis of the relationship between physical function and mortality in ambulatory older men

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    Background. Low physical performance is an important characteristic of frailty and sarcopenia. In this study, we wanted to assess and compare the predictive value of physical function measurements for all-cause mortality in older men. Methods. Data are from a longitudinal study of a population-based sample of 352 ambulatory older men aged 71 to 86 at study baseline. The Rapid disability rating scale-2, 36-Item short form health survey, Hand grip strength, Five times sit-to-stand test, Standing balance, and Timed Up and Go test were determined at baseline. Associations with all-cause mortality were assessed using Cox proportional hazard analyses. Age, BMI, smoking status, education, physical activity, and cognitive status were included as confounders. Follow-up exceeded 15 years. Results. The mean age of participants was 76 ± 4.2 years. Average follow-up duration was 184 ± 2 months. Seventy-eight percent (273) of the 352 men died during follow-up, with a median survival time of 110 months. All examined physical function measurements were associated with all-cause mortality. The Timed Up and Go test was the best predictor (adjusted HR per SD increase = 1.58, 95% CI = 1.40-1.79, P < 0.001) for global mortality. Conclusions. Our findings demonstrate that physical function measurements are important in the evaluation of older persons. We encourage the use of the Timed Up and Go test as a reliable, quick and feasible screening tool in clinical settings

    Building on the first decade of ART

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    Promoting adherence to antiretroviral therapy: the experience from a primary care setting in Khayelitsha, South Africa.

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    OBJECTIVE: To describe the approach used to promote adherence to antiretroviral therapy (ART) and to present the outcomes in the first primary care public sector ART project in South Africa. DESIGN: The study is a prospective open cohort, including all adult patients naive to previous ART who received antiretroviral treatment in Khayelitsha, from May 2001 to the end of 2002. Patients were followed until their most recent visit before 31 July 2003. METHODS: Plasma viral load was determined at 3, 6, 12, 18 and 24 months after ART was initiated, and CD4 cell counts 6-monthly. Kaplan-Meier estimates were determined for the cumulative proportions of patients surviving, and patients with viral load suppression and viral rebound. RESULTS: A total of 287 patients were initiated on triple therapy. The probability of survival was 86.3% at 24 months. The median CD4 cell count gain was 288 cells/microliters at 24 months. Viral load was less than 400 copies/ml in 89.2, 84.2 and 69.7% of patients at 6, 12 and 24 months, respectively. The cumulative probability of viral rebound (two consecutive HIV-RNA measurements above 400 copies/ml) after achieving an HIV-RNA measurement below 400 copies/ml was 13.2% at 18 months. CONCLUSION: The study shows that, with a standard approach to patient preparation and strategies to enhance adherence, a cohort of patients on ART can be retained in a resource-limited setting in a developing country. A high proportion of patients achieved suppression of viral replication. The subsequent probability of viral rebound was low
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