551 research outputs found

    The XMM-Newton serendipitous survey. VII. The third XMM-Newton serendipitous source catalogue

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    Thanks to the large collecting area (3 x ~1500 cm2^2 at 1.5 keV) and wide field of view (30' across in full field mode) of the X-ray cameras on board the European Space Agency X-ray observatory XMM-Newton, each individual pointing can result in the detection of hundreds of X-ray sources, most of which are newly discovered. Recently, many improvements in the XMM-Newton data reduction algorithms have been made. These include enhanced source characterisation and reduced spurious source detections, refined astrometric precision, greater net sensitivity and the extraction of spectra and time series for fainter sources, with better signal-to-noise. Further, almost 50\% more observations are in the public domain compared to 2XMMi-DR3, allowing the XMM-Newton Survey Science Centre (XMM-SSC) to produce a much larger and better quality X-ray source catalogue. The XMM-SSC has developed a pipeline to reduce the XMM-Newton data automatically and using improved calibration a new catalogue version has been produced from XMM-Newton data made public by 2013 Dec. 31 (13 years of data). Manual screening ensures the highest data quality. This catalogue is known as 3XMM. In the latest release, 3XMM-DR5, there are 565962 X-ray detections comprising 396910 unique X-ray sources. For the 133000 brightest sources, spectra and lightcurves are provided. For all detections, the positions on the sky, a measure of the quality of the detection, and an evaluation of the X-ray variability is provided, along with the fluxes and count rates in 7 X-ray energy bands, the total 0.2-12 keV band counts, and four hardness ratios. To identify the detections, a cross correlation with 228 catalogues is also provided for each X-ray detection. 3XMM-DR5 is the largest X-ray source catalogue ever produced. Thanks to the large array of data products, it is an excellent resource in which to find new and extreme objects.Comment: 23 pages, version accepted for publication in A&

    The challenges of ethical research with children

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    As especificidades da pesquisa com crianças têm ganhado visibilidade nas produções acadêmicas em diversas áreas de conhecimento, com destaque para a Sociologia da Infância, principalmente a partir dos “novos estudos sobre a infância” os quais emergiram ao final da década de 1980. Essa visibilidade acontece devida a questões como: a discussão sobre as imagens da infância, construídas socio-historicamente; o reconhecimento da condição das crianças enquanto atores sociais, portanto, seres competentes, que atribuem significações a suas experiências e contextos; e o reconhecimento das crianças enquanto sujeitos de direitos, reconhecimento este pautado pela Doutrina da Proteção Integral. Permeadas por essas questões, as pesquisas com crianças agregam a questão da Ética nas atividades desenvolvidas na relação pesquisador-criança. No contexto dessa discussão, este trabalho propõe refletir sobre essas questões e os cuidados éticos nesse tipo de pesquisa, considerando a condição da criança enquanto sujeito de direitos. Foi realizado um recorte da produção acadêmica representativa na área da Sociologia da Infância nas duas últimas décadas, identificando quais aspectos aparecem nas preocupações dos autores, quais abordagens norteiam a discussão desses aspectos e, principalmente, que concepção de infância está presente nessa produção.The specificities of research with children have gained visibility in scientific publications in various areas of knowledge, especially in Sociology of Childhood and the “new studies of childhood”, which emerged at the end of the 1980s. This fact is due to discussions about childhood from a socio-historical perspective; the recognition of children as social actors and therefore able to give meaning to their experiences and contexts; and the recognition of children as individuals entitled to rights, according to the Doutrina da Proteção Integral (Full Protection Doctrine). Therefore, research ethics is an essential element of good research governance, especially in terms of activities related to the relationship between the researcher and child. Accordingly, the objective of this study is to examine and explore these issues, considering the child as an individual entitled to rights. A literature review of articles published in the last two decades in the area of Sociology of Childhood was conducted to identify the main issues and topics addressed, the approaches that guided the discussions and, especially, to identify the conception of childhood present in these studies.CIEC - Centro de Investigação em Estudos da Criança, IE, UMinho (UI 317 da FCT), Portuga

    Macroevolutionary Patterns in the Aphidini Aphids (Hemiptera: Aphididae): Diversification, Host Association, and Biogeographic Origins

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    , the most diverse genus in the family. We used a combined dataset of one nuclear and four mitochondrial DNA regions. A molecular dating approach, calibrated with fossil records, was used to estimate divergence times of these taxa.Most generic divergences in Aphidini occurred in the Middle Tertiary, and species-level divergences occurred between the Middle and Late Tertiary. The ancestral state of host use for Aphidini was equivocal with respect to three states: monoecy on trees, heteroecy, and monoecy on grasses. The ancestral state of Rhopalosiphina likely included both heteroecy and monoecy, whereas that of Aphidina was most likely monoecy. The divergence times of aphid lineages at the generic or subgeneric levels are close to those of their primary hosts. The species-level divergences in aphids are consistent with the diversification of the secondary hosts, as a few examples suggest. The biogeographic origin of Aphidini as a whole was equivocal, but the major lineages within Aphidina likely separated into Nearctic, Western Palearctic, and Eastern Palearctic regions.Most generic divergences in Aphidini occurred in the Middle Tertiary when primary hosts, mainly in the Rosaceae, were diverging, whereas species-level divergences were contemporaneous with diversification of the secondary hosts such as Poaceae in the Middle to Late Tertiary. Our results suggest that evolution of host alternation within Aphidini may have occurred during the Middle Tertiary (Oligocene) when the secondary hosts emerged

    A cross-sectional study examining predictors of visit frequency to local green space and the impact this has on physical activity levels

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    Background Lack of physical activity (PA) is a growing public health concern. There is a growing body of literature that suggests a positive relationship may exist between the amount of local green space near one?s home and PA levels. For instance, park proximity has been shown to predict PA levels amongst certain populations. However, there is little evidence for the role of relatedness towards nature and perceptions of local green space on this relationship. The aim of this study was to examine, in a National UK sample, whether subjective indices associated with local green space were better predictors of visit frequency to local green space and PA levels compared to objectively measured quantity of local green space. Methods A cross-sectional survey was designed. From a random sample, 2079 working age adults responded to an online survey in September 2011. Demographics, self-reported PA, objective measures of the local environment (including local green space, road coverage, and environmental deprivation), were assessed in conjunction with perceptions of local green space and nature relatedness. Quantity of local green space was assessed by cross-referencing respondents? home postcodes with general land use databases. Regression models were conducted to assess which of our independent variables best predicted visit frequency to local green space and/or meeting PA guidelines. In addition, an ordinal regression was run to examine the relationship between visit frequency to local green space and the likelihood of meeting national PA guidelines. Results Nature relatedness was the strongest predictor for both visit frequency to local green space and meeting PA guidelines. Results show that perceived quality is a better predictor of visit frequency to local green space than objective quantity of local green space. The odds of achieving the recommended amount of PA was over four times greater for people who visited local green space once per week compared to never going (OR 4.151; 95 % CI, 2.40 to 7.17). Conclusions These results suggest that perceptions of local green space and nature relatedness play an important role in the relationship between local green space and PA. Considering the known health benefits of PA, our results are potentially important for public health interventions, policy making and environmental planning

    Reduced Mature MicroRNA Levels in Association with Dicer Loss in Human Temporal Lobe Epilepsy with Hippocampal Sclerosis

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    Hippocampal sclerosis (HS) is a common pathological finding in patients with temporal lobe epilepsy (TLE) and is associated with altered expression of genes controlling neuronal excitability, glial function, neuroinflammation and cell death. MicroRNAs (miRNAs), a class of small non-coding RNAs, function as post-transcriptional regulators of gene expression and are critical for normal brain development and function. Production of mature miRNAs requires Dicer, an RNAase III, loss of which has been shown to cause neuronal and glial dysfunction, seizures, and neurodegeneration. Here we investigated miRNA biogenesis in hippocampal and neocortical resection specimens from pharmacoresistant TLE patients and autopsy controls. Western blot analysis revealed protein levels of Dicer were significantly lower in certain TLE patients with HS. Dicer levels were also reduced in the hippocampus of mice subject to experimentally-induced epilepsy. To determine if Dicer loss was associated with altered miRNA processing, we profiled levels of 380 mature miRNAs in control and TLE-HS samples. Expression of nearly 200 miRNAs was detected in control human hippocampus. In TLE-HS samples there was a large-scale reduction of miRNA expression, with 51% expressed at lower levels and a further 24% not detectable. Primary transcript (pri-miRNAs) expression levels for several tested miRNAs were not different between control and TLE-HS samples. These findings suggest loss of Dicer and failure of mature miRNA expression may be a feature of the pathophysiology of HS in patients with TLE

    Testing Developmental Pathways to Antisocial Personality Problems

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    This study examined the development of antisocial personality problems (APP) in young adulthood from disruptive behaviors and internalizing problems in childhood and adolescence. Parent ratings of 507 children’s (aged 6–8 years) symptoms of attention deficit hyperactivity disorder, oppositional defiant disorder, and anxiety, were linked to self-ratings of adolescents’ (aged 14–16 years) symptoms of depression, substance use, conduct problems, and somatic problems, to predict self-ratings of APP in young adulthood (age 20–22 years). The findings suggested a hierarchical development of antisocial behavior problems. Despite being positively associated with conduct problems in adolescence, neither internalizing problems nor substance use added to the prediction of APP in young adulthood from conduct problems in adolescence. The developmental pathways to APP in young adulthood did not differ by gender

    Miniature Schnauzers under primary veterinary care in the UK in 2013: demography, mortality and disorders

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    Individual dog breeds are often reported as predisposed to specific breed-related disorders but reliable epidemiological data on disease prevalence are sparse. The Miniature Schnauzer in the UK is a popular small breed dog that is often considered as relatively healthy and long-lived, but is this really true? This study aimed to use data from the VetCompass™ Programme at the Royal Veterinary College to characterise the demography, mortality and common disorders of the general population of Miniature Schnauzers under veterinary care in the UK

    Modeling linkage disequilibrium increases accuracy of polygenic risk scores

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