5,097 research outputs found

    Executive abilities in children with congenital visual impairment in mid-childhood.

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    The role of vision and vision deprivation in the development of executive function (EF) abilities in childhood is little understood; aspects of EF such as initiative, attention orienting, inhibition, planning and performance monitoring are often measured through visual tasks. Studying the development and integrity of EF abilities in children with congenital visual impairment (VI) may provide important insights into the development of EF and also its possible relationship with vision and non-visual senses. The current study investigates non-visual EF abilities in 18 school-age children of average verbal intelligence with VI of differing levels of severity arising from congenital disorders affecting the eye, retina, or anterior optic nerve. Standard auditory neuropsychological assessments of sustained and divided attention, phonemic, semantic and switching verbal fluency, verbal working memory, and ratings of everyday executive abilities by parents were undertaken. Executive skills were compared to age-matched typically-sighted (TS) typically-developing children and across levels of vision (mild to moderate VI [MVI] or severe to profound VI [SPVI]). The results do not indicate significant differences or deficits on direct assessments of verbal and auditory EF between the groups. However, parent ratings suggest difficulties with everyday executive abilities, with the greatest difficulties in those with SPVI. The findings are discussed as possibly reflecting increased demands of behavioral executive skills for children with VI in everyday situations despite auditory and verbal EF abilities in the typical range for their age. These findings have potential implications for clinical and educational practices

    Rapid acidification of mode and intermediate waters in the southwestern Atlantic Ocean

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    Observations along the southwestern Atlantic WOCE A17 line made during the Dutch GEOTRACES-NL programme (2010–2011) were compared with historical data from 1994 to quantify the changes in the anthropogenic component of the total pool of dissolved inorganic carbon (?Cant). Application of the extended multi-linear regression (eMLR) method shows that the ?Cant from 1994 to 2011 has largely remained confined to the upper 1000 dbar. The greatest changes occur in the upper 200 dbar in the Subantarctic Zone (SAZ), where a maximum increase of 37 ”mol kg-1 is found. South Atlantic Central Water (SACW) experienced the highest rate of increase in Cant, at 0.99 ± 0.14 ”mol kg-1 yr-1, resulting in a maximum rate of decrease in pH of 0.0016 yr-1. The highest rates of acidification relative to ?Cant, however, were found in Subantarctic Mode Water (SAMW) and Antarctic Intermediate Water (AAIW). The low buffering capacity of SAMW and AAIW combined with their relatively high rates of Cant, increase of 0.53 ± 0.11 and 0.36 ± 0.06 ”mol kg-1 yr-1, respectively, has lead to rapid acidification in the SAZ, and will continue to do so whilst simultaneously reducing the chemical buffering capacity of this significant CO2 sink

    The ‘expat factor’: the influence of working time on women's decisions to undertake international assignments in the oil and gas industry

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    This article examines the effect of working time on women’s willingness to go on expatriate assignments in the oil and gas exploration and production sector. The research draws upon an analysis of two case study firms’ international assignment and working time policies, semi-structured interviews with 14 Human Resource staff responsible for policy design and implementation, and a survey of the views of 71 women expatriates, supported by in-depth interviews with 26 of the survey respondents. The research identifies an ‘expat factor’: assignees state that long hours are inherent in expatriation and necessary to further their careers. However in practice, working time is not excessive and flexible working practices are utilised. Hours of work have little effect on women’s decisions to undertake long-term assignments but alternatives such as short-term and commuter assignments are unpopular as their working patterns are disruptive to family life. This article contributes to theory development by linking two discrete frameworks that explain women’s career choices when they strive to balance their career goals with their families and by identifying a career compromise threshold when expatriation is rejected in favour of family considerations. A model is proposed to link working time/patterns to women’s international assignment participation

    Mesoscale features create hotspots of carbon uptake in the Antarctic Circumpolar Current

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    The influence of eddy structures on the seasonal depletion of dissolved inorganic carbon (DIC) and carbon dioxide (CO2) disequilibrium was investigated during a trans-Atlantic crossing of the Antarctic Circumpolar Current (ACC) in austral summer 2012. The Georgia Basin, downstream of the island of South Georgia (54-55°S, 36-38°W) is a highly dynamic region due to the mesoscale activity associated with the flow of the Subantarctic Front (SAF) and Polar Front (PF). Satellite sea-surface height and chlorophyll-a anomalies revealed a cyclonic cold core that dominated the northern Georgia Basin that was formed from a large meander of the PF. Warmer waters influenced by the SAF formed a smaller anticyclonic structure to the east of the basin. Both the cold core and warm core eddy structures were hotspots of carbon uptake relative to the rest of the ACC section during austral summer. This was most amplified in the cold core where greatest CO2 undersaturation (-78 ”atm) and substantial surface ocean DIC deficit (5.1 mol m-2) occurred. In the presence of high wind speeds, the cold core eddy acted as a strong sink for atmospheric CO2 of 25.5 mmol m-2 day-1. Waters of the warm core displayed characteristics of the Polar Frontal Zone (PFZ), with warmer upper ocean waters and enhanced CO2 undersaturation (-59 ”atm) and depletion of DIC (4.9mol m-2). A proposed mechanism for the enhanced carbon uptake across both eddy structures is based on the Ekman eddy pumping theory: (i) the cold core is seeded with productive (high chlorophyll-a) waters from the Antarctic Zone and sustained biological productivity through upwelled nutrient supply that counteracts DIC inputs from deep waters; (ii) horizontal entrainment of low-DIC surface waters (biological uptake) from the PFZ downwell within the warm core and cause relative DIC-depletion in the upper water column. The observations suggest that the formation and northward propagation of cold core eddies in the region of the PF could project low-DIC waters towards the site of Antarctic Intermediate Water formation and enhance CO2 drawdown into the deep ocean

    Cadmium uptake, translocation and tolerance in the hyperaccumulator Arabidopsis halleri

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    Arabidopsis halleri is a well-known zinc (Zn) hyperaccumulator, but its status as a cadmium (Cd) hyperaccumulator is less certain. Here, we investigated whether A. halleri can hyperaccumulate Cd and whether Cd is transported via the Zn pathway. Growth and Cd and Zn uptake were determined in hydroponic experiments with different Cd and Zn concentrations. Short-term uptake and root-to-shoot transport were measured with radioactive Cd-109 and Zn-65 labelling. A. halleri accumulated > 1000 mg Cd kg(-1) in shoot dry weight at external Cd concentrations >= 5 mu m>, but the short-term uptake rate of Cd-109 was much lower than that of Zn-65. Zinc inhibited short-term Cd-109 uptake kinetics and root-to-shoot translocation, as well as long-term Cd accumulation in shoots. Uptake of Cd-109 and Zn-65 were up-regulated, respectively, by low iron (Fe) or Zn status. A. halleri was much less tolerant to Cd than to Zn. We conclude that A. halleri is able to hyperaccumulate Cd partly, at least, through the Zn pathway, but the mechanisms responsible for cellular Zn tolerance cannot detoxify Cd effectively

    New methods of evaluation of the flavour composition in annihilation by double hemisphere tagging at LEP/SLC energies

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    Two new methods are proposed to extract the flavour contents of the events produced at LEP/SLC, together with the classification matrix of a tagging by hemispheres. By utilising the tagging obtained in both hemispheres, the efficiencies, backgrounds and flavour compositions are directly obtained by fitting the data. A minimal dependence on modelling and a consistent treatment of systematic errors are achieved by applying these methods. The choice of the tagging algorithm is irrelevant in the methods, provided that similar efficiencies are reached. As an example, a multivariate analysis technique combining the tracking information given by a microvertex detector has been applied to extract the Z → b overlineb branching ratio using a standard simulation of a LEP/SLC experiment

    EU Accession Migration: National Insurance Number Allocations and the Geographies of Polish Labour Immigration to the UK

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    This paper addresses the challenge of measuring the extent of immigration to the UK following EU Accession in 2004, and argues that the most commonly used databases (UK Census, Labour Force Survey and Worker Registration Scheme) can be supplemented by the National Insurance Number (NINo) Allocations database, and demonstrates the utility of this data for future research by outlining the geography of immigration derived from NINo. The paper makes three important contributions through the thorough analysis of a data source currently underexploited in migration studies; first that the NINo, when used as a indicator of migration per se offers some interesting insights into migration in the UK, and secondly that as a tool for comprehensively measuring the registration of migrants working legally in the UK, it offers a means of constructing a internal geography of (legal) labour migration, as the paper demonstrates. Third, the analysis also identifies self-employment as a potentially important missing driver behind EU Accession Migration
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