447 research outputs found

    Introducing SpatialGridBuilder: A new system for creating geo-coded datasets

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    Researchers in the conflict research community have become increasingly aware that we can no longer depend on state-aggregated data. Numerous factors at the substate level affect the nature of human interactions, so if we really want to understand conflict, we need to find more appropriate units of analysis. However, while many conflict researchers have realized this, actually taking the next step and performing data analysis on spatial data grids has remained a rather elusive goal for many because of the difficulty of learning the new techniques to perform such analyses. This paper introduces SpatialGridBuilder, a new, freely available, open-source system with the goal of empowering conflict researchers with no background in GIS methods to start their own spatial analyses. SpatialGridBuilder allows the researcher to: (a) create entirely new spatial datasets, based on the needs of their own research; (b) import their own spatial data; (c) easily add a range of important variables to the datasets, including commonly used conflict variables, plus new variables that have not been presented before; and (d) visualize graphical renderings of this data. Having done this, SpatialGridBuilder will then export the dataset for the researcher to analyse using conventional statistical methods. This article introduces the new program, and demonstrates how it can be used to set up such a statistical analysis. It also shows how different results can be achieved by building grids of different resolutions, thereby encouraging researchers to choose grid resolutions appropriate to their research questions and data. The article also introduces a novel means of determining infrastructure complexity, using Google maps

    NSAID Use Selectively Increases the Risk of Non-Fatal Myocardial Infarction: A Systematic Review of Randomised Trials and Observational Studies

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    Recent clinical trials and observational studies have reported increased coronary events associated with non steroidal anti-inflammatory drugs (NSAIDs). There appeared to be a disproportionate increase in non-fatal versus fatal events, however, numbers of fatal events in individual studies were too small, and event rates too low, to be meaningful.We undertook a pooled analysis to investigate the effect of NSAIDs on myocardial infarction (MI) risk with the specific aim to differentiate non-fatal from fatal events.We searched Pubmed (January, 1990 to March, 2010) for observational studies and randomised controlled trials that assessed the effect of NSAIDs (traditional or selective COX-2 inhibitors [coxibs]) on MI incidence separately for fatal and non-fatal events. Summary estimates of relative risk (RR) for non-fatal and fatal MIs were calculated with a random effects model.NSAID therapy carried a RR of 1.30 (95% CI, 1.20-1.41) for non-fatal MI with no effect on fatal MI (RR 1.02, 95% CI, 0.89-1.17) in six observational studies. Overall, the risk increase for non-fatal MI was 25% higher (95% CI, 11%-42%) than for fatal MI. The two studies that included only individuals with prior cardiovascular disease presented risk estimates for non-fatal MI on average 58% greater (95% CI, 26%-98%) than those for fatal MI. In nine randomised controlled trials, all investigating coxibs, the pooled RR estimate for non-fatal MI was 1.61 (95% CI, 1.04-2.50) and 0.86 (95% CI 0.51-1.47) for fatal MIs.NSAID use increases the risk of non-fatal MI with no substantial effect on fatal events. Such differential effects, with potentially distinct underlying pathology may provide insights into NSAID-induced coronary pathology. We studied the association between the use of nonsteroidal anti-inflammatory drugs (NSAIDs) and the risk of myocardial infarction (MI), separating non-fatal from fatal events, summarizing the evidence from both observational studies and randomised controlled trials. An increased risk of non-fatal MI was clearly found in both types of studies while use of NSAID did not confer an increased risk of fatal MI. Our findings provide support for the concept that thrombi generated under NSAID treatment could be different from spontaneous thrombi

    Grid computing in image analysis

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    Diagnostic surgical pathology or tissue–based diagnosis still remains the most reliable and specific diagnostic medical procedure. The development of whole slide scanners permits the creation of virtual slides and to work on so-called virtual microscopes. In addition to interactive work on virtual slides approaches have been reported that introduce automated virtual microscopy, which is composed of several tools focusing on quite different tasks. These include evaluation of image quality and image standardization, analysis of potential useful thresholds for object detection and identification (segmentation), dynamic segmentation procedures, adjustable magnification to optimize feature extraction, and texture analysis including image transformation and evaluation of elementary primitives

    Heterozygous Mutations of FREM1 Are Associated with an Increased Risk of Isolated Metopic Craniosynostosis in Humans and Mice

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    The premature fusion of the paired frontal bones results in metopic craniosynostosis (MC) and gives rise to the clinical phenotype of trigonocephaly. Deletions of chromosome 9p22.3 are well described as a cause of MC with variably penetrant midface hypoplasia. In order to identify the gene responsible for the trigonocephaly component of the 9p22.3 syndrome, a cohort of 109 patients were assessed by high-resolution arrays and MLPA for copy number variations (CNVs) involving 9p22. Five CNVs involving FREM1, all of which were de novo variants, were identified by array-based analyses. The remaining 104 patients with MC were then subjected to targeted FREM1 gene re-sequencing, which identified 3 further mutant alleles, one of which was de novo. Consistent with a pathogenic role, mouse Frem1 mRNA and protein expression was demonstrated in the metopic suture as well as in the pericranium and dura mater. Micro-computed tomography based analyses of the mouse posterior frontal (PF) suture, the human metopic suture equivalent, revealed advanced fusion in all mice homozygous for either of two different Frem1 mutant alleles, while heterozygotes exhibited variably penetrant PF suture anomalies. Gene dosage-related penetrance of midfacial hypoplasia was also evident in the Frem1 mutants. These data suggest that CNVs and mutations involving FREM1 can be identified in a significant percentage of people with MC with or without midface hypoplasia. Furthermore, we present Frem1 mutant mice as the first bona fide mouse model of human metopic craniosynostosis and a new model for midfacial hypoplasia

    Raphe-mediated signals control the hippocampal response to SRI antidepressants via miR-16

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    Serotonin reuptake inhibitor (SRI) antidepressants such as fluoxetine (Prozac), promote hippocampal neurogenesis. They also increase the levels of the bcl-2 protein, whose overexpression in transgenic mice enhances adult hippocampal neurogenesis. However, the mechanisms underlying SRI-mediated neurogenesis are unclear. Recently, we identified the microRNA miR-16 as an important effector of SRI antidepressant action in serotonergic raphe and noradrenergic locus coeruleus (LC). We show here that miR-16 mediates adult neurogenesis in the mouse hippocampus. Fluoxetine, acting on serotonergic raphe neurons, decreases the amount of miR-16 in the hippocampus, which in turn increases the levels of the serotonin transporter (SERT), the target of SRI, and that of bcl-2 and the number of cells positive for Doublecortin, a marker of neuronal maturation. Neutralization of miR-16 in the hippocampus further exerts an antidepressant-like effect in behavioral tests. The fluoxetine-induced hippocampal response is relayed, in part, by the neurotrophic factor S100β, secreted by raphe and acting via the LC. Fluoxetine-exposed serotonergic neurons also secrete brain-derived neurotrophic factor, Wnt2 and 15-Deoxy-delta12,14-prostaglandin J2. These molecules are unable to mimic on their own the action of fluoxetine and we show that they act synergistically to regulate miR-16 at the hippocampus. Of note, these signaling molecules are increased in the cerebrospinal fluid of depressed patients upon fluoxetine treatment. Thus, our results demonstrate that miR-16 mediates the action of fluoxetine by acting as a micromanager of hippocampal neurogenesis. They further clarify the signals and the pathways involved in the hippocampal response to fluoxetine, which may help refine therapeutic strategies to alleviate depressive disorders
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