1,252 research outputs found

    Stable isotope studies on humans and animals from Tell Tweini, Syria (2600-550 BC)

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    Tell Tweini is a coastal Syrian site with settlement remains of diverse periods between the Early Bronze Age and the Iron Age (2600-550 BC). Inside urban contexts in Field A at the site, eleven burials have been unearthed. Most date to the Middle Bronze Age (2000-1600 BC), including one collective grave. Stable isotope ratio analysis (δ13C and δ15N) was carried out on human remains from these Middle Bronze Age graves in order to reconstruct human dietary practices. In addition, a large sample of faunal remains from the major periods of occupation at Tell Tweini, Early Bronze Age (2600-2000 BC), Middle Bronze Age (2000-1600 BC), Late Bronze Age (1600-1200 BC) and Iron Age (1200-550 BC) have been subjected to stable isotope ratio analysis. The large dataset on animals is the first of its kind for the period and region. The results add to a reconstruction of the human diet. More importantly, they allow us to make diachronic inferences on livestock management practices and the natural environment. The results will be discussed in the context of data on the faunal composition through time at Tell Tweini as well as that of the palaeo-environmental data which points to an abrupt climatic change at the transition between the Late Bronze Age and the Iron Age

    Embodied energy analysis of the refurbishment of a small detached building

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    Energy efficient design principles and the minimisation of operational energy requirements have been demonstrated in the refurbishment of a small existing residential building. Significant thought has been given to these areas, together with an emphasis on the minimisation of resource consumption and material wastage. However, less consideration has been given to the embodied energy of the additional materials, components and systems required to meet these aims. The additional embodied energy may reduce the advantages of minimising the operational energy consumption by extending the energy payback period beyond the life of the building. In general, the embodied energy of buildings and their products has been found to be significant, when national average input-output data is used to fill gaps in traditional life-cycle assessment inventories. Through the use of an input-outputbased hybrid embodied energy analysis, the embodied energy of this refurbished building has increased by 63% compared to the existing building, showing the impact that filling the gaps in traditional inventories can have on energy payback periods.<br /

    Estimating specific surface area of fine stream bed sediments from geochemistry

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    Specific surface area (SSA) of headwater stream bed sediments is a fundamental property which determines the nature of sediment surface reactions and influences ecosystem-level, biological processes. Measurements of SSA – commonly undertaken by BET nitrogen adsorption – are relatively costly in terms of instrumentation and operator time. A novel approach is presented for estimating fine (2.5 mg kg−1), four elements were identified as significant predictors of SSA (ordered by decreasing predictive power): V > Ca > Al > Rb. The optimum model from these four elements accounted for 73% of the variation in bed sediment SSA (range 6–46 m2 g−1) with a root mean squared error of prediction – based on leave-one-out cross-validation – of 6.3 m2 g−1. It is believed that V is the most significant predictor because its concentration is strongly correlated both with the quantity of Fe-oxides and clay minerals in the stream bed sediments, which dominate sediment SSA. Sample heterogeneity in SSA – based on triplicate measurements of sub-samples – was a substantial source of variation (standard error = 2.2 m2 g−1) which cannot be accounted for in the regression model. The model was used to estimate bed sediment SSA at the other 1792 sites and at 30 duplicate sites where an extra sediment sample had been collected, 25 m from the original site. By delineating sub-catchments for the headwater sediment sites only those sub-catchments were selected with a dominant (>50% of the sub-catchment area) bedrock formation and land use type; the bedrock and land use classes accounted for 39% and 7% of the variation in bed sediment SSA, respectively. Variation in estimated, fine bed sediment SSA from the paired, duplicate sediment sites was small (2.7 m2 g−1), showing that local variation in SSA at stream sites is modest when compared to that between catchments. How the approach might be applied in other environments and its potential limitations are discussed

    "The dirty hand in the latex glove": a study of hand hygiene compliance when gloves are worn.

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    Wearing of gloves reduces transmission of organisms by healthcare workers' hands but is not a substitute for hand hygiene. Results of previous studies have varied as to whether hand hygiene is worse when gloves are worn. Most studies have been small and used nonstandardized assessments of glove use and hand hygiene. We sought to observe whether gloves were worn when appropriate and whether hand hygiene compliance differed when gloves were worn
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