3,008 research outputs found

    Region of Interest Growing Neural Gas for Real-Time Point Cloud Processing

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    This paper proposes a real-time topological structure learning method based on concentrated/distributed sensing for a 2D/3D point cloud. First of all, we explain a modified Growing Neural Gas with Utility (GNG-U2) that can learn the topological structure of 3D space environment and color information simultaneously by using a weight vector. Next, we propose a Region Of Interest Growing Neural Gas (ROI-GNG) for realizing concentrated/distributed sensing in real-time. In ROI-GNG, the discount rates of the accumulated error and utility value are variable according to the situation. We show experimental results of the proposed method and discuss the effectiveness of the proposed method

    Quantitative approaches to energy and glucose homeostasis: machine learning and modelling for precision understanding and prediction

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    Obesity is a major global public health problem. Understanding how energy homeostasis is regulated, and can become dysregulated, is crucial for developing new treatments for obesity. Detailed recording of individual behaviour and new imaging modalities offer the prospect of medically relevant models of energy homeostasis that are both understandable and individually predictive. The profusion of data from these sources has led to an interest in applying machine learning techniques to gain insight from these large, relatively unstructured datasets. We review both physiological models and machine learning results across a diverse range of applications in energy homeostasis, and highlight how modelling and machine learning can work together to improve predictive ability. We collect quantitative details in a comprehensive mathematical supplement. We also discuss the prospects of forecasting homeostatic behaviour and stress the importance of characterizing stochasticity within and between individuals in order to provide practical, tailored forecasts and guidance to combat the spread of obesity

    Methylomic profiling of cortex samples from completed suicide cases implicates a role for PSORS1C3 in major depression and suicide.

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    This is the final version of the article. Available from Nature Publishing Group via the DOI in this record.Major depressive disorder (MDD) represents a major social and economic health issue and constitutes a major risk factor for suicide. The molecular pathology of suicidal depression remains poorly understood, although it has been hypothesised that regulatory genomic processes are involved in the pathology of both MDD and suicidality. In this study, genome-wide patterns of DNA methylation were assessed in depressed suicide completers (n=20) and compared with non-psychiatric, sudden-death controls (n=20) using tissue from two cortical brain regions (Brodmann Area 11 (BA11) and Brodmann Area 25 (BA25)). Analyses focused on identifying differentially methylated regions (DMRs) associated with suicidal depression and epigenetic variation were explored in the context of polygenic risk scores for major depression and suicide. Weighted gene co-methylation network analysis was used to identify modules of co-methylated loci associated with depressed suicide completers and polygenic burden for MDD and suicide attempt. We identified a DMR upstream of the PSORS1C3 gene, subsequently validated using bisulfite pyrosequencing and replicated in a second set of suicide samples, which is characterised by significant hypomethylation in both cortical brain regions in MDD suicide cases. We also identified discrete modules of co-methylated loci associated with polygenic risk burden for suicide attempt, but not major depression. Suicide-associated co-methylation modules were enriched among gene networks implicating biological processes relevant to depression and suicidality, including nervous system development and mitochondria function. Our data suggest that there are coordinated changes in DNA methylation associated with suicide that may offer novel insights into the molecular pathology associated with depressed suicide completers.We are grateful to all of the patients and control subjects who contributed to this study. The authors would like to acknowledge support of the Brain and Behaviour Research Foundation through a NARSAD Young Investigator Grant to TMM and from the UK Medical Research Council (MRC) (grant number MR/K013807/1) to JM. ZK would like to acknowledge funding from the NIH grant (grant number NIMH 1R21MH094771). The Douglas Bell Canada Brain Bank is supported by the FRQS through the Quebec Network on Suicide, Mood Disorders and Related Disorders, and by Brain Canada through an infrastructure grant. We acknowledge Niamh Mullins and Professor Catherine Lewis, King’s College London, for kindly supplying us with the suicide attempt GWAS data

    The comparative effectiveness of statin therapy in selected chronic diseases compared with the remaining population

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    Total cholesterol (TC) concentration is the most commonly used measure of statin efficacy in the UK. This study aimed to evaluate the effectiveness of statins in lowering TC, cardiovascular events (CV) and mortality five common chronic diseases (chronic obstructive pulmonary disease (COPD), osteoarthritis (OA), rheumatoid arthritis (RA), chronic kidney disease (CKD), and diabetes mellitus (DM)) and to compare effectiveness with the rest of the population not recorded as having these diseases

    Ultraluminous Infrared Galaxies

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    At luminosities above ~10^{11} L_sun, infrared galaxies become the dominant population of extragalactic objects in the local Universe (z < 0.5), being more numerous than optically selected starburst and Seyfert galaxies, and QSOs at comparable bolometric luminosity. At the highest luminosities, ultraluminous infrared galaxies (ULIGs: L_ir > 10^{12} L_sun), outnumber optically selected QSOs by a factor of ~1.5-2. All of the nearest ULIGs (z < 0.1) appear to be advanced mergers that are powered by both a circumnuclear starburst and AGN, both of which are fueled by an enormous concentration of molecular gas (~10^{10} M_sun) that has been funneled into the merger nucleus. ULIGs may represent a primary stage in the formation of massive black holes and elliptical galaxy cores. The intense circumnuclear starburst that accompanies the ULIG phase may also represent a primary stage in the formation of globular clusters, and the metal enrichment of the intergalactic medium by gas and dust expelled from the nucleus due to the combined forces of supernova explosions and powerful stellar winds.Comment: LaTex, 6 pages with 4 embedded .eps figures. Postscript version plus color plates available at http://www.ifa.hawaii.edu/users/sanders/astroph/s186/plates.html To appear in "Galaxy Interactions at Low and High Redshift" IAU Symposium 186, Kyoto, Japan, eds. J.E. Barnes and D.B. Sander

    Evaluating the landscape of fear between apex predatory sharks and mobile sea turtles across a large dynamic seascape

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    The ‘‘landscape of fear’’ model has been proposed as a unifying concept in ecology, describing, in part, how animals behave and move about in their environment. The basic model predicts that as an animal’s landscape changes from low to high risk of predation, prey species will alter their behavior to risk avoidance. However, studies investigating and evaluating the landscape of fear model across large spatial scales (tens to hundreds of thousands of square kilometers) in dynamic, open, aquatic systems involving apex predators and highly mobile prey are lacking. To address this knowledge gap, we investigated predator–prey relationships between tiger sharks (Galeocerdo cuvier) and loggerhead turtles (Caretta caretta) in the North Atlantic Ocean. This included the use of satellite tracking to examine shark and turtle distributions as well as their surfacing behaviors under varying levels of home range overlap. Our findings revealed patterns that deviated from our a priori predictions based on the landscape of fear model. Specifically, turtles did not alter their surfacing behaviors to risk avoidance when overlap in shark–turtle core home range was high. However, in areas of high overlap with turtles, sharks exhibited modified surfacing behaviors that may enhance predation opportunity. We suggest that turtles may be an important factor in determining shark distribution, whereas for turtles, other life history trade-offs may play a larger role in defining their habitat use. We propose that these findings are a result of both biotic and physically driven factors that independently or synergistically affect predator–prey interactions in this system. These results have implications for evolutionary biology, community ecology, and wildlife conservation. Further, given the difficulty in studying highly migratory marine species, our approach and conclusions may be applied to the study of other predator–prey systems.Bald Head Island ConservancyBritish Chelonia GroupNatural Environmental Research CouncilWAVE Foundation/Newport Aquarium CincinnatiPADI project AWARESEATURTLE.ORGWhitener Foundation (NC); an Endangered Species Act Section 6 Cooperative Agreement with NOAA Fisheries and the Grays Reef National Marine Sanctuary (South Carolina and Georgia)Batchelor FoundationDinsey Conservation Fun

    Methylomic markers of persistent childhood asthma: a longitudinal study of asthma-discordant monozygotic twins.

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    This is a freely-available open access publication. Please cite the published version which is available via the DOI link in this record.Asthma is the most common chronic inflammatory disorder in children. The aetiology of asthma pathology is complex and highly heterogeneous, involving the interplay between genetic and environmental risk factors that is hypothesized to involve epigenetic processes. Our aim was to explore whether methylomic variation in early childhood is associated with discordance for asthma symptoms within monozygotic (MZ) twin pairs recruited from the Environmental Risk (E-Risk) longitudinal twin study. We also aimed to identify differences in DNA methylation that are associated with asthma that develops in childhood and persists into early adulthood as these may represent useful prognostic biomarkers. RESULTS: We examined genome-wide patterns of DNA methylation in buccal cell samples collected from 37 MZ twin pairs discordant for asthma at age 10. DNA methylation at individual CpG sites demonstrated significant variability within discordant MZ twin pairs with the top-ranked nominally significant differentially methylated position (DMP) located in the HGSNAT gene. We stratified our analysis by assessing DNA methylation differences in a sub-group of MZ twin pairs who remained persistently discordant for asthma at age 18. The top-ranked nominally significant DMP associated with persisting asthma is located in the vicinity of the HLX gene, which has been previously implicated in childhood asthma. CONCLUSIONS: We identified DNA methylation differences associated with childhood asthma in peripheral DNA samples from discordant MZ twin pairs. Our data suggest that differences in DNA methylation associated with childhood asthma which persists into early adulthood are distinct from those associated with asthma which remits.Medical Research Council (MRC)National Institute of Child Health and Development (NICHD)American Asthma FoundationMRC Centenary Awar

    Estimated GFR reporting is associated with decreased nonsteroidal anti-inflammatory drug prescribing and increased renal function

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    Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used; however, they are also nephrotoxic with both acute and chronic effects on kidney function. Here we determined NSAID prescribing before and after estimated GFR (eGFR) reporting and evaluate renal function in patients who used NSAIDs but stopped these after their first eGFR report. A population-based longitudinal analysis using a record-linkage database was conducted with the GFR estimated using the four-variable equation from the MDRD study and analyzed by trend test, paired t-test, and logistic regression modeling. Prescriptions for NSAIDs significantly decreased from 39,459 to 35,415 after implementation of eGFR reporting from the second quarter of 2005 compared with the first quarter of 2007. Reporting eGFR was associated with reduced NSAID prescriptions (adjusted odds ratio, 0.78). NSAID prescription rates in the 6 months before April 2006 were 18.8, 15.4, and 7.0% in patients with CKD stages 3, 4, and 5 and 15.5, 10.7, and 6.3%, respectively, after eGFR reporting commenced. In patients who stopped NSAID treatment, eGFR significantly increased from 45.9 to 46.9, 23.9 to 27.1, and 12.4 to 26.4 ml/min per 1.73 m(2) in 1340 stage 3 patients, 162 stage 4 patients, and 9 stage 5 patients, respectively. Thus, NSAID prescribing decreased after the implementation of eGFR reporting, and there were significant improvements in estimated renal function in patients who stopped taking NSAIDs. Hence, eGFR reporting may result in safer prescribing

    A posterior epidural mass causing paraparesis in a 20-year-old healthy individual

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    We present a case of a posterior epidural abscess at the thoracic vertebral level causing paraparesia in a young, healthy individual with no otherwise predisposing factors, with normal laboratory findings, as diagnosed using fat-suppressed MR imaging. Spinal epidural abscess is a rare condition, encountered mostly in the midthoracic or lower lumbar vertebral levels of elderly patients, that has a high mortality and morbidity (18-31%) when diagnosis and treatment is delayed. It is rarely spontaneous and is usually accompanied by spinal osteomyelitis. Diagnosis is rather easy in cases of vertebral osteomyelitis or when classical clinical, laboratory and imaging findings are present. However, cases of spontaneous development, with no predisposing factors, and lack of abscess suggesting clinical and laboratory findings may be a diagnostic challenge. In such cases, other posterior epidural masses such as schwannoma, neurofibroma, meningioma and hematoma should be considered in the differential diagnosis. Both the clinician and the radiology physician should have a high suspicion of epidural abscesses, because their early diagnosis and treatment is important. In addition to routine MR images, fat-suppressed MR images prove helpful in the diagnosis of spontaneous epidural abscesses by showing the inflammatory changes in the paraspinal area

    The role of bacteria in the pathogenesis and progression of idiopathic pulmonary fibrosis

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    Rationale:Idiopathic pulmonaryfibrosis (IPF)isa progressivelung disease of unknown cause that leads to respiratory failure and death within 5 years of diagnosis. Overt respiratory infection and immunosuppression carry a high morbidity and mortality, and polymorphisms in genes related to epithelial integrity and host defense predispose to IPF. Objectives: To investigate the role of bacteria in the pathogenesis and progression of IPF. Methods: We prospectively enrolled patients diagnosed with IPF according to international criteria together with healthy smokers, nonsmokers, and subjectswithmoderate chronic obstructive pulmonary disease as control subjects. Subjects underwent bronchoalveolar lavage (BAL), from which genomic DNA was isolated. The V3–V5 region of the bacterial 16S rRNA gene was amplified, allowing quantification of bacterial load and identification of communities by 16S rRNA quantitative polymerase chain reaction and pyrosequencing. Measurements and Main Results: Sixty-five patients with IPF had double the burden of bacteria in BAL fluid compared with 44 control subjects. Baseline bacterial burden predicted the rate of decline in lung volume and risk of death and associated independently with the rs35705950 polymorphism of the MUC5B mucin gene, a proven host susceptibilityfactorfor IPF. Sequencing yielded912,883 high-quality reads from all subjects.WeidentifiedHaemophilus, Streptococcus,Neisseria, and Veillonella spp. to be more abundant in cases than control subjects. Regression analyses indicated that these specific operational taxonomic units as well as bacterial burden associated independently with IPF. Conclusions: IPF is characterized by an increased bacterial burden in BAL that predicts decline in lung function and death. Trials of antimicrobial therapy are needed to determine if microbial burden is pathogenic in the disease
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