645 research outputs found

    Iodine status of soils, grain crops, and irrigation waters in Pakistan

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    A study was carried out across 86 locations of the country to investigate iodine supply potential of soils, grains and underground waters for onward design of an environmental intervention in Pakistan. Wheat crops were the principal crop in this study since it supplies 75 % of calorific energy in an average Pakistani diet. TMAH-extractable iodine in soils provided a geometric mean of 0.66 µg g−1, far lower than the worldwide mean of 3.0 µg g−1 for soil iodine. Bioavailable (water-extractable) iodine concentration had a geometric mean of 2.4 % (of TMAH-extractable iodine). Median iodine concentrations in tube well sourced waters were 7.3 µg L−1. Median wheat grain-iodine concentrations were 0.01 µg g−1. In most of the grain samples, TMAH-extractable iodine was below detection limit of 0.01 µg g−1. The highest wheat grain iodine was measured on a soil having highest TMAH-extractable iodine. An iodine intake of 25.4 µg a day has been estimated based on median wheat grain iodine measured and groundwater consumption compared to world health organisation (WHO) recommendations of iodine intake of 150 µg a day. This nominal intake of iodine is alarming since 60 % of Pakistani households do not consume iodised salt

    The impact of Chinese import penetration on the South African manufacturing sector

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    This article uses a Chenery-type decomposition and econometric estimation to evaluate the impact of Chinese trade on production and employment in South African manufacturing from 1992 to 2010. The results suggest that increased import penetration from China caused South African manufacturing output to be 5 per cent lower in 2010 than it otherwise would have been. The estimated reduction of total employment in manufacturing as a result of trade with China is larger – in 2010 about 8 per cent – because the declines in output were concentrated on labour-intensive industries and because the increase in imports raised labour productivity within industries

    Dexamphetamine boosts naming treatment effects in chronic aphasia

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    To date, minimal research has investigated the effect of combining dexamphetamine with standard naming therapy after stroke. The present study used a double-blind, placebo-controlled, multiple baseline, crossover design with two individuals in the chronic stage of stroke recovery. Each individual attended two 4-week blocks of naming therapy (two to three treatment sessions per week). Dexamphetamine (10 mg) was administered at the start of each session during one therapy block, while a placebo was administered during the other therapy block. Therapy progress on treated and untreated items was assessed by a confrontation naming task during and after each therapy block. Both individuals showed greater progress in therapy and maintenance of therapy gains when behavioral treatment was combined with dexamphetamine rather than placebo, although this gain was only statistically significant in one individual. There was no significant improvement on a control task (nonword reading) in either individual. The results provide preliminary evidence that dexamphetamine paired with combined semantic and phonological therapy may be beneficial for the treatment of naming disorders in chronic aphasia

    Dopamine and semantic activation: An investigation of masked direct and indirect priming

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    To investigate the effects of dopamine on the dynamics of semantic activation, 39 healthy volunteers were randomly assigned to ingest either a placebo (n = 24) or a levodopa (it = 16) capsule. Participants then performed a lexical decision task that implemented a masked priming paradigm. Direct and indirect semantic priming was measured across stimulus onset asynchronies (SOAs) of 250, 500 and 1200 ms. The results revealed significant direct and indirect semantic priming effects for the placebo group at SOAs of 250 ms and 500 ms, but no significant direct or indirect priming effects at the 1200 ms SOA. In contrast, the levodopa group showed significant direct and indirect semantic priming effects at the 250 ms SOA, while no significant direct or indirect priming effects were evident at the SOAs of 500 ins or 1200 ms. These results suggest that dopamine has a role in modulating both automatic and attentional aspects of semantic activation according to a specific time course. The implications of these results for current theories of dopaminergic modulation of semantic activation are discussed

    'Ava’: a Beaker-associated woman from a cist at Achavanich, Highland, and the story of her (re-) discovery and subsequent study

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    This contribution describes the discovery and subsequent investigation of a cist in a rock-cut pit at Achavanich, Highland. Discovered and excavated in 1987, the cist was found to contain the tightly contracted skeletal remains of a young woman, accompanied by a Beaker, three flint artefacts and a cattle scapula. Initial post excavation work established a date for the skeleton together with details of her age and sex, and preliminary pollen analysis of sediments attaching to the Beaker was undertaken. The findings were never fully published and, upon the death of the excavator, Robert Gourlay, the documentary archive was left in the Highland Council Archaeology Unit. Fresh research in 2014–17, initiated and co-ordinated by the first-named author and funded by the Society of Antiquaries of Scotland with assistance from National Museums Scotland, the Natural History Museum and Harvard Medical School, has produced a significant amount of new information on the individual and on some of the items with which she was buried. This new information includes two further radiocarbon dates, a more detailed osteological report, isotopic information pertaining to the place where she had been raised and to her diet, histological information on the decomposition of her body, and genetic information that sheds light on her ancestry, her hair, eye and skin colour and her intolerance of lactose. (This is the first time that an ancient DNA report has been published in the Proceedings.) Moreover, a facial reconstruction adds virtual flesh to her bones. The significance of this discovery within the Chalcolithic to Early Bronze Age of this part of Scotland is discussed, along with the many and innovative ways in which information on this individual, dubbed ‘Ava’, has been disseminated around the world.Copyright © 2018 rests with the Society and the individual authors. Except where otherwise noted, this work is licensed under CreativeCommons Attribution-NonCommercial-No Derivatives licence.https://creativecommons.org/licenses/by-nc-nd/4.0/ The permission to reproduce the Society's copyright-protected ma-terial does not extend to any material which is identified as being the copyright of a third party. Authorisation to reproduce such material must be obtained from the copyright holders concerned. The attached file is the published pdf

    Optimisation of plutonium separations using TEVA cartridges and ICP-MS/MS analysis for applicability to large-scale studies in tropical soils

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    The analysis of plutonium (Pu) in soil samples can inform the understanding of soil erosion processes globally. However, there are specific challenges associated for analysis in tropical soils and so an optimal analytical methodology ensuring best sensitivity is critical. This method aimed to demonstrate the feasibility of sample preparation and analysis of Pu isotopes in African soils, considering the environmental and cost implications applicable to low-resource laboratories. The separation procedure builds upon previous work using TEVA columns, further demonstrating their usefulness for the reduction of uranium (U) interference in ICP-MS analysis with enhanced selectivity for Pu. Here several steps were optimised to enhance Pu recovery, reducing method blank concentration, and improving the separation efficiency through the determination of the elution profiles of U and Pu. The elimination of the complexing agent in the eluent, increased the spike recovery by improving matrix tolerance of the plasma, and simplified the separation procedure, improving throughput by 20%. The subsequent method was validated through the analysis of Certified Reference Material IAEA-384, where high accuracy and improved precision of measurement were demonstrated (measured value 114 ± 12 versus certified value 108 ± 13 Bq kg−1). Optimisation of the column separation, along with the analysis of the samples using O2 gas in ICP-MS/MS mode to mass shift Pu isotopes away from interfering molecular U ions provided a simple, robust, and cost-effective method with low achievable method detection limits of 0.18 pg kg−1 239+240Pu, applicable to the detection of ultra-trace fallout Pu in African soils

    Patterns of abundance across geographical ranges as a predictor for responses to climate change: Evidence from UK rocky shores

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    Aim: Understanding patterns in the abundance of species across thermal ranges can give useful insights into the potential impacts of climate change. The abundant-centre hypothesis suggests that species will reach peak abundance at the centre of their thermal range where conditions are optimal, but evidence in support of this hypothesis is mixed and limited in geographical and taxonomic scope. We tested the applicability of the abundant-centre hypothesis across a range of intertidal organisms using a large, citizen science-generated data set. Location: UK. Methods: Species' abundance records were matched with their location within their thermal range. Patterns in abundance distribution for individual species, and across aggregated species abundances, were analysed using Kruskal–Wallis tests and quantile general additive models. Results: Individually, invertebrate species showed increasing abundances in the cooler half of the thermal range and decreasing abundances in the warmer half of the thermal range. The overall shape for aggregated invertebrate species abundances reflected a broad peak, with a cool-skewed maximum abundance. Algal species showed little evidence for an abundant-centre distribution individually, but overall the aggregated species abundances suggested a hump-backed abundance distribution
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