63 research outputs found

    GraviDy, a GPU modular, parallel direct-summation N-body integrator: Dynamics with softening

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    A wide variety of outstanding problems in astrophysics involve the motion of a large number of particles (N106N\gtrsim 10^{6}) under the force of gravity. These include the global evolution of globular clusters, tidal disruptions of stars by a massive black hole, the formation of protoplanets and the detection of sources of gravitational radiation. The direct-summation of NN gravitational forces is a complex problem with no analytical solution and can only be tackled with approximations and numerical methods. To this end, the Hermite scheme is a widely used integration method. With different numerical techniques and special-purpose hardware, it can be used to speed up the calculations. But these methods tend to be computationally slow and cumbersome to work with. Here we present a new GPU, direct-summation NN-body integrator written from scratch and based on this scheme. This code has high modularity, allowing users to readily introduce new physics, it exploits available high-performance computing resources and will be maintained by public, regular updates. The code can be used in parallel on multiple CPUs and GPUs, with a considerable speed-up benefit. The single GPU version runs about 200 times faster compared to the single CPU version. A test run using 4 GPUs in parallel shows a speed up factor of about 3 as compared to the single GPU version. The conception and design of this first release is aimed at users with access to traditional parallel CPU clusters or computational nodes with one or a few GPU cards

    An Analysis of Seed Colour During Ripening of Cabernet Sauvignon Grapes

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    This case study examines seed colour during ripening using an exhaustive colorimetric analysis. The aim was to associate the chemical ripening with the seed colour in order to estimate the ripening stages of Cabernet Sauvignon grapes. Cluster samples, obtained from a vertical shoot-positioned vineyard in central Chile, were monitored for their technological and phenolic maturity, as well as for the colorimetric and chemical characteristics of the seeds. The colours of the scanned seed images were determined by human as well as by computer vision. In the first case, an expert assigned a colour to each seed part. In the second case, a computer program estimated the colours of the scanned seed images. An exhaustive analysis of seed colour was proposed, instead of a general observation of seed browning. The seed colour presented a wide range of colours, from moss green to dark brown, depending on the maturity and the face observed. The ripening stages identified, along with the chemical and colorimetric information gathered, were under ripe seed (brown with green traces), ripe seed (dark brown with green traces) and overripe seed (dark brown without any green traces). A new way to quantify seed colour is shown in this paper

    Work exposures and development of cardiovascular diseases: A systematic review

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    Introduction: Cardiovascular diseases (CVDs) are the number one cause of death, and there is evidence that work exposures could be associated with their development. This study aimed to systematically review observational studies of adults exposed to job strain, effort–reward imbalance, long working hours, job insecurity, shift work, and occupational noise, and assess the association of those work exposures with CVDs. Methods: The Navigation Guide framework was applied. The population were adults of working age (18–65), and cohort and case–control studies were included. The work exposures were job strain, effort–reward imbalance, long working hours, job insecurity, shift work, and occupational noise. The outcomes were cerebrovascular diseases, ischaemic heart disease, and hypertensive diseases. The selection, data extraction, risk of bias assessment, and quality assessment were carried out by two reviewers independently and disagreements were solved by a third reviewer or by consensus. The synthesis of the results was done by applying the ‘vote counting based on direction’ method, and the results were summarized in an effect direction plot. The strength of the evidence for every risk factor and CVD was defined by consensus. Results: A total of 17 643 papers were initially identified in the literature search, but after applying the filters by title and abstract, and full text, 86 studies were finally included. From the included studies, sufficient evidence was found of the harmfulness of job strain for cerebrovascular disease and ischemic heart disease. Furthermore, there was sufficient evidence of the harmfulness of shift work for ischemic heart disease. Evidence of no relationship was found between long working hours and shift work with ischaemic heart disease and hypertensive disease, respectively. The other associations of work exposures and CVDs had limited or inadequate evidence of harmfulness. Conclusions: In this comprehensive review, there was sufficient evidence of a harmful relationship between job strain, shift work, and CVDs. For the other work exposures, more high-quality studies are needed. In order to improve current prevention strategies for CVDs, the findings of this review imply that job strain and shift work are work exposures that constitute additional risk factors that could be approached as targets for worksite interventions

    Workplace interventions for cardiovascular diseases: protocol of a systematic review and meta-analysis

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    INTRODUCTION: Cardiovascular diseases (CVDs) are the number one cause of death globally, impacting on public and private sectors. Current traditional interventions to prevent CVDs are mainly provided in healthcare centres and even when they are effective, they are not enough to reduce the rising prevalence; therefore, additional strategies are needed. Evidence suggests that health interventions in the workplace supply numerous benefits improving cardiovascular risk factor profiles in individuals. Hence, the aim of this systematic review and meta-analysis is to collate the evidence from randomised controlled trials, cluster randomised trials and quasi-experimental studies of workplace interventions to determine their effectiveness in terms of improving cardiovascular risk factors and preventing CVDs. METHODS AND ANALYSIS: EMBASE, PsycINFO, PubMed, the Cochrane Central Register of Controlled Trials, LILACS, Scopus, Web of Science, WHO International Clinical Trials Registry Platform, ClinicalTrials.gov and ProQuest Dissertations & Theses Global will be searched to include articles on workplace interventions in adults for CVDs events, cardiometabolic risk factors or behavioural risk factors. The study selection, data extraction, risk of bias and the assessment of the quality of the body of evidence will be conducted by two reviewers working in parallel and disagreements will be resolved by consensus or consultations with a third reviewer. Data synthesis will be done by meta-analysis using random-effects models when possible, otherwise the vote counting method will be applied. Statistical heterogeneity will be assessed by a χ(2) test and I(2) statistics. The quality of the body of evidence for each outcome will be assessed by applying the Grading of Recommendations, Assessment, Development and Evaluation approach. ETHICS AND DISSEMINATION: Ethical approval is not required for this systematic review protocol. The results of the systematic review will be published in a peer-reviewed journal and will be publicly available. PROSPERO REGISTRATION NUMBER: CRD42021276161

    Production, Transmission, Pathogenesis, and Control of Dengue Virus: A Literature-Based Undivided Perspective

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    Dengue remains one of the most serious and widespread mosquito-borne viral infections in human beings, with serious health problems or even death. About 50 to 100 million people are newly infected annually, with almost 2.5 billion people living at risk and resulting in 20,000 deaths. Dengue virus infection is especially transmitted through bites of Aedes mosquitos, hugely spread in tropical and subtropical environments, mostly found in urban and semiurban areas. Unfortunately, there is no particular therapeutic approach, but prevention, adequate consciousness, detection at earlier stage of viral infection, and appropriate medical care can lower the fatality rates. This review offers a comprehensive view of production, transmission, pathogenesis, and control measures of the dengue virus and its vectors.This work was supported by CONICYT PIA/APOYO CCTE AFB170007

    Work Exposures and Development of Cardiovascular Diseases: A Systematic Review

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    INTRODUCTION: Cardiovascular diseases (CVDs) are the number one cause of death, and there is evidence that work exposures could be associated with their development. This study aimed to systematically review observational studies of adults exposed to job strain, effort–reward imbalance, long working hours, job insecurity, shift work, and occupational noise, and assess the association of those work exposures with CVDs. METHODS: The Navigation Guide framework was applied. The population were adults of working age (18–65), and cohort and case–control studies were included. The work exposures were job strain, effort–reward imbalance, long working hours, job insecurity, shift work, and occupational noise. The outcomes were cerebrovascular diseases, ischaemic heart disease, and hypertensive diseases. The selection, data extraction, risk of bias assessment, and quality assessment were carried out by two reviewers independently and disagreements were solved by a third reviewer or by consensus. The synthesis of the results was done by applying the ‘vote counting based on direction’ method, and the results were summarized in an effect direction plot. The strength of the evidence for every risk factor and CVD was defined by consensus. RESULTS: A total of 17 643 papers were initially identified in the literature search, but after applying the filters by title and abstract, and full text, 86 studies were finally included. From the included studies, sufficient evidence was found of the harmfulness of job strain for cerebrovascular disease and ischemic heart disease. Furthermore, there was sufficient evidence of the harmfulness of shift work for ischemic heart disease. Evidence of no relationship was found between long working hours and shift work with ischaemic heart disease and hypertensive disease, respectively. The other associations of work exposures and CVDs had limited or inadequate evidence of harmfulness. CONCLUSIONS: In this comprehensive review, there was sufficient evidence of a harmful relationship between job strain, shift work, and CVDs. For the other work exposures, more high-quality studies are needed. In order to improve current prevention strategies for CVDs, the findings of this review imply that job strain and shift work are work exposures that constitute additional risk factors that could be approached as targets for worksite interventions. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020179972

    Targeting Serous Epithelial Ovarian Cancer with Designer Zinc Finger Transcription Factors

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    Ovarian cancer is the leading cause of death among gynecological malignancies. It is detected at late stages when the disease is spread through the abdominal cavity in a condition known as peritoneal carcinomatosis. Thus, there is an urgent need to develop novel therapeutic interventions to target advanced stages of ovarian cancer. Mammary serine protease inhibitor (Maspin) represents an important metastasis suppressor initially identified in breast cancer. Herein we have generated a sequence-specific zinc finger artificial transcription factor (ATF) to up-regulate the Maspin promoter in aggressive ovarian cancer cell lines and to interrogate the therapeutic potential of Maspin in ovarian cancer. We found that although Maspin was expressed in some primary ovarian tumors, the promoter was epigenetically silenced in cell lines derived from ascites. Transduction of the ATF in MOVCAR 5009 cells derived from ascitic cultures of a TgMISIIR-TAg mouse model of ovarian cancer resulted in tumor cell growth inhibition, impaired cell invasion, and severe disruption of actin cytoskeleton. Systemic delivery of lipid-protamine-RNA nanoparticles encapsulating a chemically modified ATF mRNA resulted in inhibition of ovarian cancer cell growth in nude mice accompanied with Maspin re-expression in the treated tumors. Gene expression microarrays of ATF-transduced cells revealed an exceptional specificity for the Maspin promoter. These analyses identified novel targets co-regulated with Maspin in human short-term cultures derived from ascites, such as TSPAN12, that could mediate the anti-metastatic phenotype of the ATF. Our work outlined the first targeted, non-viral delivery of ATFs into tumors with potential clinical applications for metastatic ovarian cancers
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