2,945 research outputs found

    Geochemical reactivity of subsurface sediments as potential buffer to anthropogenic inputs: a strategy for regional characterization in the Netherlands

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    Geochemical reactivity of subsurface sediments as potential buffer to anthropogenic inputs: a strategy for regional characterization in the Netherland

    The Forum of European Geological Surveys Geochemistry Task Group 1994-1996 inventory

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    The Forum of European Geological Surveys (FOREGS) includes representatives from 33 European countries and is responsible for co-ordinating Geological Survey activities in Europe. The FOREGS Geochemistry Task Group was established in 1994 to develop a strategy for the preparation of European geochemical maps following the recommendations of the International Geological Correlation Programme (IGCP) Project 259 ‘International Geochemical Mapping’ (now the International Union of Geological Sciences (IUGS) /International Association of Geochemistry and Cosmochemistry (IAGC) Working Group on Global Geochemical Baselines). The FOREGS geochemistry programme is aimed at preparing a standardised European geochemical baseline to IGCP-259 standards. The principal aims of this dataset will be for environmental purposes, as a baseline for the assessment of the extent and distribution of contaminated land in the context of variations in the natural geochemical background, but it will also have applications in resource assessment and for the development of policy for the sustainable management of metalliferous mineral and other resources. The first phase of the programme was the compilation of an inventory of geochemical data based on the results of a questionnaire completed by Geological Surveys and related organisations throughout the FOREGS community. The results show that the sample types which have been used most extensively are stream sediment (26% coverage), surface water (19% coverage) and soil (11% coverage). Stream sediments have been collected using a narrow range of mesh sizes (< 150–< 200 μm), but soil samples have been collected according to two different conventions: some surveys used a similar mesh size range to that used for stream sediments while others employed the < 1000 or < 2000 μm fractions traditionally used by soil surveys. Sample densities range from 1 sample per 0.5 km2 to 1 per 3500 km2. Various analytical methods have been used, but most of the available data have been calibrated using international reference materials, and data for the most important of the potentially harmful elements (PHEs) are available for most datasets. Systematic radiometric data are available for only a small proportion of Europe, a situation which compares very unfavourably with that in Australia, North America, the former Soviet Union and many developing countries. Recommendations are made for increasing the compatibility of geochemical methods between national geochemical surveys as a basis for the preparation of a series of European geochemical maps. The next stage of the FOREGS Geochemistry Task Group will be the collection of the Global Reference Network of samples against which to standardise national datasets according to the methods recommended in the final report of the IGCP 259 programme

    LONG-TERM CHANGES IN CANADA GOOSE NEST SUCCESS AND NEST DENSITIES AT AN IOWA WETLAND COMPLEX

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    Giant Canada geese (Branta canadensis maxima) were extirpated from Iowa by the early 1900s due to unregulated hunting, egg gathering, and wetland drainage in the nineteenth century (Bishop 1978). Ef- forts to reintroduce Canada geese in Iowa began in 1964 (Bishop and Howing 1972) and involved releasing flightless adults and goslings at nearly 30 sites across the state (Zenner and LaGrange 1998a). In 1972, 13 flightless pairs were released at Rice Lake Wildlife Management Area (WMA; Bishop 1978). By 1989, the breeding population of Canada geese at Rice Lake WMA had increased to 420 nesting adults (G. G. Zenner, Iowa Department of Natural Resources, unpublished data). Canada goose nest success and nest densities were documented from 1989–1991 on extant islands at Rice Lake WMA (Zenner and LaGrange 1998b). Rice Lake WMA (43.379497, –93.472715) is located in north-central Iowa and lies within the southernmost portion of the Prairie Pothole Region. This wetland complex consists of Rice Lake, a 409-ha shallow, natural lake with a maximum depth of 3 m and 20 natural islands ranging in size from 0.04 to 3.9 ha, and Joice Slough, a 73-ha marsh with a maximum depth of 1 m and 15 natural islands ranging in size from 0.02 to 3.19 ha (Zenner and LaGrange 1998b). During 1989–1991, potential Canada goose nest sites included islands, elevated structures, and muskrat houses. Over the course of that study, drought conditions left Joice Slough completely dry and dramatically lowered water levels at Rice Lake, exposing islands to increased predator activity. Despite the drought, nest densities were high (68–158 nests/ha) and nest success ranged from 40–58% (Zenner and LaGrange 1998b)

    Empowering patients with high myopia:The significance of education

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    Purpose: To investigate the status of patient education among highly myopic individuals focusing on the presence, sources, content, timing of the education and impact on patients. Methods: Self-reported data were collected through an online 13-item questionnaire consisting of open and multiple-choice questions. The questionnaire was sent to 250 highly myopic members of a patient organization in the Netherlands, of whom 128 (51%) responded. Results: At least one acute event had occurred in 66% (84/128) of participants at the time of the questionnaire. Among all participants, 25% (32/128) had not received patient education regarding alarm symptoms for any of these events. Among those who had been informed, the ophthalmologist was the most frequent (57%, 73/128) source of information. Participants who visited the ophthalmologist annually were more frequently informed than participants without annual visits (53%, 26/49 versus 26%, 9/35, p = 0.002). Those not informed were more likely to have a more than 3 days patient delay (92%, 12/13). Doctors delay was also present; 26% (22/84) of the participants with alarm symptoms had to wait 2 or more days before the first appointment. Long-term consequences of myopia had been discussed with 102 participants (80%, 102/128), again with the ophthalmologist as the most frequent source (59%, 76/128). Perspectives: Many myopic individuals have not been educated about their increased risk of acute events, which can result in patient delay and serious consequences with respect to visual prognosis. These findings underscore the critical importance of integrating patient education across the entire ophthalmic care chain for myopia.</p

    Exposure to challenging behaviours and burnout symptoms among care staff:the role of psychological resources

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    Background Staff supporting individuals with intellectual disabilities are at risk of burnout symptoms. Evidence suggests an association between exposure to challenging behaviours of individuals with intellectual disabilities and burnout symptoms of staff, but the protective role of staff psychological resources in this relation has been understudied. Method We investigated the association between exposure to challenging behaviours and burnout symptoms of staff and the direct and moderating effects of several psychological resources. Staff (N = 1271) completed an online survey concerning burnout symptoms (subscale Emotional Exhaustion of the Maslach Burnout Inventory), exposure to challenging behaviours and a range of potential psychological resources. We examined main and moderating effects with multilevel analyses. In order to control for the multiple comparisons, P values corrected for false discovery rate (P-FDR) were reported. Results We found a direct relation between exposure to challenging behaviours and increased levels of burnout symptoms in staff (b = .15, t(670) = 4.466, P-FDR <.0001). Perceived supervisor social support (b = -.97, t(627) = -7.562, P-FDR <.0001), staff self-efficacy (b = -.23, t(673) = -3.583, P-FDR <.0001), resilience (b = -.19, t(668) = -2.086, P-FDR <.05) and extraversion (b = -.20, t(674) = -3.514, P-FDR <.05) were associated with reduced burnout symptoms. None of the proposed psychological resources moderated the association between exposure to challenging behaviours and burnout symptoms of staff. Conclusions Of the psychological resources found to be associated with reduced risk of burnout symptoms, staff self-efficacy and access of staff to supervisor social support seem to be the factors that can be influenced best. These factors thus may be of importance in reducing the risk of developing burnout symptoms and improving staff well-being, even though the current study was not designed to demonstrate causal relations between psychological resources and burnout symptoms

    Congenital Prosopagnosia: Multistage Anatomical and Functional Deficits in Face Processing Circuitry

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    Face recognition is a primary social skill which depends on a distributed neural network. A pronounced face recognition deficit in the absence of any lesion is seen in congenital prosopagnosia. This study investigating 24 congenital prosopagnosic subjects and 25 control subjects aims at elucidating its neural basis with fMRI and voxel-based morphometry. We found a comprehensive behavioral pattern, an impairment in visual recognition for faces and buildings that spared long-term memory for faces with negative valence. Anatomical analysis revealed diminished gray matter density in the bilateral lingual gyrus, the right middle temporal gyrus, and the dorsolateral prefrontal cortex. In most of these areas, gray matter density correlated with memory success. Decreased functional activation was found in the left fusiform gyrus, a crucial area for face processing, and in the dorsolateral prefrontal cortex, whereas activation of the medial prefrontal cortex was enhanced. Hence, our data lend strength to the hypothesis that congenital prosopagnosia is explained by network dysfunction and suggest that anatomic curtailing of visual processing in the lingual gyrus plays a substantial role. The dysfunctional circuitry further encompasses the fusiform gyrus and the dorsolateral prefrontal cortex, which may contribute to their difficulties in long-term memory for complex visual information. Despite their deficits in face identity recognition, processing of emotion related information is preserved and possibly mediated by the medial prefrontal cortex. Congenital prosopagnosia may, therefore, be a blueprint of differential curtailing in networks of visual cognition

    Распределение металлической фазы в синтетических алмазах типа «карбонадо»

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    Studying of a structural structure synthetic «carbonado» is spent by a method of electronic scanning microscopy. It is established, that the surface «carbonado» is covered by the large diamond crystals reaching 200 microns, having obviously expressed structure of growth. On a surface of these crystals observed drops of metal-catalyst (nickel) of a submicronic range. It is established, that the structure synthetic «carbonado» represents interpenetrating skeletons from diamond and ceramic-metal phases

    Термопружний стан шаруватих термочутливих циліндрів і куль за конвективно-променевого теплообміну

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    Розроблено методику розв’язування одновимірних статичних задач термопружності для шаруватих циліндрів і куль за конвективно-променевого нагрівання з урахуванням лінійної залежності коефіцієнтів теплопровідності та довільного характеру залежності інших фізико-механічних характеристик від температури. Задачі теплопровідності зведено, незалежно від кількості шарів, до розв’язування системи двох нелінійних алгебричних рівнянь. У задачах термопружності неперервні в межах кожного шару коефіцієнти рівнянь апроксимовано кусково-сталими функціями. Проведено числовий аналіз температурних полів і напружень у двошарових тілах.The method for solving one-dimensional static thermoelasticity problems is developed for layered cylinders and spheres under convective and radiation heating, taking into account linear dependence of heat conductivity coefficients and arbitrary character of dependence of other physical and mechanical characteristics on a temperature. Problems of heat conductivity have been reduced to the system of two nonlinear algebraic equations regardless of the number of layers. In the thermoelasticity problems the continuous within every layer coefficients of equations are approximated by piecewise constant functions. The numerical analysis of the temperature fields and stresses is conducted for two-layered bodies.Разработана методика решения одномерных статических задач термоупругости для слоистых цилиндров и сфер при конвективно-лучевом нагреве с учетом линейной зависимости коэффициентов теплопроводности и произвольного характера зависимости других физико-механических характеристик от температуры. Задачи теплопроводности сведены, независимо от количества слоев, к решению системы двух нелинейных алгебраических уравнений. В задачах термоупругости непрерывные в пределах каждого слоя коэффициенты уравнений аппроксимированы кусочно-постоянными функциями. Проведен численный анализ температурных полей и напряжений в двухслойных телах

    Association of Rhegmatogenous Retinal Detachment Incidence With Myopia Prevalence in the Netherlands

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    Importance The incidence of rhegmatogenous retinal detachment (RRD) is partly determined by its risk factors, such as age, sex, cataract surgery, and myopia. Changes in the prevalence of these risk factors could change RRD incidence in the population. Objective To determine whether the incidence of RRD in the Netherlands has changed over recent years and whether this change is associated with an altered prevalence of RRD risk factors. Design, Setting, and Participants This cohort study included data from all 14 vitreoretinal clinics in the Netherlands, as well as a large Dutch population-based cohort study. All patients who underwent surgical repair for a primary RRD in the Netherlands from January 1 to December 31, 2009, and January 1 to December 31, 2016, were analyzed, in addition to all participants in the population-based Rotterdam Study who were examined during these years. Analysis began February 2018 and ended November 2019. Exposures RRD risk factors, including age, male sex, cataract extraction, and myopia. Main Outcomes and Measures Age-specific RRD incidence rate in the Dutch population, as well as change in RRD incidence and risk factor prevalence between 2009 and 2016. Results In 2016, 4447 persons (median [range] age, 61 [3-96] years) underwent surgery for a primary RRD within the Netherlands, resulting in an RRD incidence rate of 26.2 per 100 000 person-years (95% CI, 25.4-27.0). The overall RRD incidence rate had increased by 44% compared with similar data from 2009. The increase was observed in both phakic (1994 in 2009 to 2778 in 2016 [increase, 39%]) and pseudophakic eyes (1004 in 2009 to 1666 in 2016 [increase, 66%]), suggesting that cataract extraction could not solely account for the overall rise. Over the same period, the prevalence of mild, moderate, and severe myopia among persons aged 55 to 75 years had increased by 15.6% (881 of 4561 [19.3%] vs 826 of 3698 [22.3%]), 20.3% (440 of 4561 [9.6%] vs 429 of 3698 [11.6%]), and 26.9% (104 of 4561 [2.3%] vs 107 of 3698 [2.9%]), respectively, within the population-based Rotterdam Study. Conclusions and Relevance In this study, an increase was observed in primary RRD incidence in the Netherlands over a 7-year period, which could not be explained by a different age distribution or cataract surgical rate. A simultaneous myopic shift in the Dutch population may be associated, warranting further population-based studies on RRD incidence and myopia prevalence. This cohort study assesses whether the incidence of rhegmatogenous retinal detachment has changed over recent years and whether this change is associated with an altered prevalence of rhegmatogenous retinal detachment risk factors in the Netherlands. Question What is the incidence of primary rhegmatogenous retinal detachment (RRD) in the Netherlands and has it changed over recent years? Findings In this cohort study, 4447 individuals in the Netherlands underwent surgery for RRD in 2016, resulting in an incidence of 26.2 per 100 000 inhabitants, an increase of 44% compared with similar data from 2009. Over the same period, an increase in myopia prevalence in a Dutch population-based cohort study was observed. Meaning In the Netherlands, an increase in RRD incidence may be associated with a simultaneous myopic shift in the population

    Book Review of Serendipity: An Ecologist’s Quest to Understand Nature

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    A common thought among graduate students is: “how do established scientists get where they are today?” In Serendipity: An Ecologist’s Quest to Understand Nature, James Estes offers a personal reflection on research experiences spanning his 50-year career, beginning as a Ph.D. student in 1970 and concluding with recognition as a member of the National Academy of Sciences in 2014. Estes chronologically outlines the foundational trophic cascade ecology research that he and colleagues conducted in the Aleutian Islands, examining key relationships among kelp forests, sea otters, sea urchins, and killer whales through anecdotal stories of achievement and challenge. Estes’ 3 main goals in writing this book are to: (1) recount what he had learned from 50 years of research; (2) provide a larger story of how predators and prey interact with one another; and (3) explain how science “really happens.
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