182 research outputs found

    The Transfer of Evolved Artificial Immune System Behaviours between Small and Large Scale Robotic Platforms

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    This paper demonstrates that a set of behaviours evolved in simulation on a miniature robot (epuck) can be transferred to a much larger scale platform (a virtual Pioneer P3-DX) that also differs in shape, sensor type, sensor configuration and programming interface. The chosen architecture uses a reinforcement learning-assisted genetic algorithm to evolve the epuck behaviours, which are encoded as a genetic sequence. This sequence is then used by the Pioneers as part of an adaptive, idiotypic artificial immune system (AIS) control architecture. Testing in three different simulated worlds shows that the Pioneer can use these behaviours to navigate and solve object-tracking tasks successfully, as long as its adaptive AIS mechanism is in place.Comment: 12 pages, 3 figures, 2 tables, 9th International Conference on Artificial Evolution (EA 09)

    The lncRNA HOTAIR transcription is controlled by HNF4α-induced chromatin topology modulation

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    The expression of the long noncoding RNA HOTAIR (HOX Transcript Antisense Intergenic RNA) is largely deregulated in epithelial cancers and positively correlates with poor prognosis and progression of hepatocellular carcinoma and gastrointestinal cancers. Furthermore, functional studies revealed a pivotal role for HOTAIR in the epithelial-to-mesenchymal transition, as this RNA is causal for the repressive activity of the master factor SNAIL on epithelial genes. Despite the proven oncogenic role of HOTAIR, its transcriptional regulation is still poorly understood. Here hepatocyte nuclear factor 4-α (HNF4α), as inducer of epithelial differentiation, was demonstrated to directly repress HOTAIR transcription in the mesenchymal-to epithelial transition. Mechanistically, HNF4α was found to cause the release of a chromatin loop on HOTAIR regulatory elements thus exerting an enhancer-blocking activity

    The Snail repressor recruits EZH2 to specific genomic sites through the enrollment of the lncRNA HOTAIR in epithelial-to-mesenchymal transition

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    The transcription factor Snail is a master regulator of cellular identity and epithelial-to-mesenchymal transition (EMT) directly repressing a broad repertoire of epithelial genes. How chromatin modifiers instrumental to its activity are recruited to Snail-specific binding sites is unclear. Here we report that the long non-coding RNA (lncRNA) HOTAIR (for HOX Transcript Antisense Intergenic RNA) mediates a physical interaction between Snail and enhancer of zeste homolog 2 (EZH2), an enzymatic subunit of the polycomb-repressive complex 2 and the main writer of chromatin-repressive marks. The Snail-repressive activity, here monitored on genes with a pivotal function in epithelial and hepatic morphogenesis, differentiation and cell-type identity, depends on the formation of a tripartite Snail/HOTAIR/EZH2 complex. These results demonstrate an lncRNA-mediated mechanism by which a transcriptional factor conveys a general chromatin modifier to specific genes, thereby allowing the execution of hepatocyte transdifferentiation; moreover, they highlight HOTAIR as a crucial player in the Snail-mediated EMT.Oncogene advance online publication, 25 July 2016; doi:10.1038/onc.2016.260

    Impacts of selected Ecological Focus Area options in European farmed landscapes on climate regulation and pollination services: a systematic map protocol

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    Background: This systematic map protocol responds to an urgent policy need to evaluate key environmental benefits of new compulsory greening measures in the European Union’s Common Agricultural Policy (CAP), with the aim of building a policy better linked to environmental performance. The systematic map will focus on Ecological Focus Areas (EFAs), in which larger arable farmers must dedicate 5% of their arable land to ecologically beneficial habitats, landscape features and land uses. The European Commission’s Joint Research Centre has used a software tool called the ‘EFA calculator’ to inform the European Commission about environmental benefits of EFA implementation. However, there are gaps in the EFA calculator’s coverage of ecosystem services, especially ‘global climate regulation’, and an opportunity to use systematic mapping methods to enhance its capture of evidence, in advance of forthcoming CAP reforms. We describe a method for assembling a database of relevant, peer-reviewed research conducted in all agricultural landscapes in Europe and neighbouring countries with similar biogeography, addressing the primary question: what are the impacts of selected EFA features in agricultural land on two policy-relevant ecosystem service outcomes—global climate regulation and pollination? The method is streamlined to allow results in good time for the current, time-limited opportunity to influence reforms of the CAP greening measures at European and Member State level. Methods: We will search four bibliographic databases in English, using a predefined and tested search string that focuses on a subset of EFA options and ecosystem service outcomes. The options and outcomes are selected as those with particular policy relevance and traction. Only articles in English will be included. We will screen search results at title, abstract and full text levels, recording the number of studies deemed non-relevant (with reasons at full text). A systematic map database that displays the meta-data (i.e. descriptive summary information about settings and methods) of relevant studies will be produced following full text assessment. The systematic map database will be published as a MS-Excel database. The nature and extent of the evidence base will be discussed, and the applicability of methods to convert the available evidence into EFA calculator scores will be assessed

    The impact of change in a doctor's job position: a five-year cohort study of job satisfaction among Norwegian doctors

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    <p>Abstract</p> <p>Background</p> <p>Job satisfaction among physicians may be of importance to their individual careers and their work with patients. We lack prospective studies on whether a change in a doctor's job position influences their job satisfaction over a five-year period if we control for other workload factors.</p> <p>Methods</p> <p>A longitudinal national cohort of all physicians who graduated in Norway in 1993 and 1994 was surveyed by postal questionnaire in 2003 (T1) and 2008 (T2). Outcomes were measured with a 10-item job satisfaction scale. Predictor variables in a multiple regression model were: change in job position, reduction in work-home interface stress, reduction in work hours, age, and gender.</p> <p>Results</p> <p>A total of 59% of subjects (306/522) responded at both time points. The mean value of job satisfaction in the total sample increased from 51.6 (SD = 9.0) at T1 to 53.4 (SD = 8.2) at T2 (paired <it>t </it>test, <it>t </it>= 3.8, <it>p </it>< 0.001). The major groups or positions at T1 were senior house officers (45%), chief specialists in hospitals (23%), and general practitioners (17%), and the latter showed the highest levels of job satisfaction. Physicians who changed position during the period (n = 176) experienced an increase in job satisfaction from 49.5 (SD = 8.4) in 2003 to 52.9 (SD = 7.5) in 2008 (paired <it>t </it>test, <it>t </it>= 5.2, <it>p </it>< 0.001). Job satisfaction remained unchanged for physicians who stayed in the same position. There was also an increase in satisfaction among those who changed from positions other than senior house officer at T1 (<it>p </it>< 0.01). The significant adjusted predictor variables in the multiple regression model were the change in position from senior house officer at T1 to any other position (β = 2.83, <it>p </it>< 0.001), any change in job position (from any position except SHO at T1) (β = 4.18, <it>p </it>< 0.01) and reduction in work-home interface stress (β = 1.04, <it>p </it>< 0.001).</p> <p>Conclusions</p> <p>The physicians experienced an increase in job satisfaction over a five-year period, which was predicted by a change in job position and a reduction in work-home stress. This study has implications with respect to career advice for young doctors.</p

    Fatores de risco cardiovascular em pessoas semabrigo e na população geral da cidade do Porto, Portugal

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    We described the distribution of risk factors for cardiovascular disease among homeless people living in the city of Porto, Portugal. Comparisons were made between subsamples of homeless people recruited in different settings and between the overall homeless sample group and a sample of the general population. All "houseless" individuals attending one of two homeless hostels or two institutions providing meal programs on specific days were invited to participate and were matched with subjects from the general population. We estimated sex, age and education-adjusted prevalence ratios or mean differences. The prevalence of previous illicit drug consumption and imprisonment was almost twice as high among the homeless from institutions providing meal programs. This group also showed lower mean systolic and diastolic blood pressure. Prevalence of smoking was almost 50% higher in the overall homeless group. Mean body mass index and waist circumference were also lower in the homeless group and its members were almost five times less likely to report dyslipidemia. Our findings contribute to defining priorities for interventions directed at this segment of society and to reducing inequalities in this extremely underprivileged populatio
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