1,302 research outputs found

    Asynchronous Graph Pattern Matching on Multiprocessor Systems

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    Pattern matching on large graphs is the foundation for a variety of application domains. Strict latency requirements and continuously increasing graph sizes demand the usage of highly parallel in-memory graph processing engines that need to consider non-uniform memory access (NUMA) and concurrency issues to scale up on modern multiprocessor systems. To tackle these aspects, graph partitioning becomes increasingly important. Hence, we present a technique to process graph pattern matching on NUMA systems in this paper. As a scalable pattern matching processing infrastructure, we leverage a data-oriented architecture that preserves data locality and minimizes concurrency-related bottlenecks on NUMA systems. We show in detail, how graph pattern matching can be asynchronously processed on a multiprocessor system.Comment: 14 Pages, Extended version for ADBIS 201

    Tuberculosis in a South African prison – a transmission modelling analysis

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    Background. Prisons are recognised internationally as institutions with very high tuberculosis (TB) burdens where transmission is predominantly determined by contact between infectious and susceptible prisoners. A recent South African court case described the conditions under which prisoners awaiting trial were kept. With the use of these data, a   mathematical model was developed to explore the interactions between incarceration conditions and TB control measures.Methods. Cell dimensions, cell occupancy, lock-up time, TB incidence and treatment delays were derived from court evidence and judicial reports. Using the Wells-Riley equation and probability analyses of contact between prisoners, we estimated the current TB transmission probability within prison cells, and estimated transmission probabilities of improved levels of case finding in combination with implementation of national and  international minimum standards for incarceration.Results. Levels of overcrowding (230%) in communal cells and poor TB case finding result in annual TB transmission risks of 90% per annum. Implementing current national or international cell occupancy  recommendations would reduce TB transmission probabilities by 30% and 50%, respectively. Improved passive case finding, modest ventilation increase or decreased lock-up time would minimally impact on transmission if introduced individually. However, active case finding together with implementation of minimum national and international standards of incarceration could reduce transmission by 50% and 94%, respectively.Conclusions. Current  conditions of detention for awaiting trial prisoners are highly conducive for spread of drug-sensitive and drug-resistant TB. Combinations of simple well-established scientific control measures should be implemented urgently.S Afr Med J 2011;101:809-813

    Tuberculosis in a South African prison - a transmission modelling analysis

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    Background. Prisons are recognised internationally as institutions with very high tuberculosis (TB) burdens where transmission is predominantly determined by contact between infectious and susceptible prisoners. A. recent South African court case described the conditions under which prisoners awaiting trial were kept. With the use of these data, a mathematical model was developed to explore the interactions between incarceration conditions and TB control measures. Methods. Cell dimensions, cell occupancy, lock-up time, TB incidence and treatment delays were derived from court evidence and judicial reports. Using the Wells-Riley equation and probability analyses of contact between prisoners, we estimated the current TB transmission probability within prison cells, and estimated transmission probabilities of improved levels of case finding in combination with implementation of national and international minimum standards for incarceration. Results. Levels of overcrowding (230%) in communal cells and Poor TB case finding result in annual TB transmission risks of 90% per annum. Implementing current national or international cell occupancy recommendations would reduce TB transmission probabilities by 30% and 50%, respectively. Improved passive case finding, modest ventilation increase or decreased lock-up time would minimally impact on transmission if introduced individually. However, active case finding together with implementation of minimum national and international standards of incarceration could reduce transmission by 50% and 94%, respectively. Conclusions. Current conditions of detention for awaiting-trial prisoners are highly conducive for spread of drug-sensitive and drug-resistant TB. Combinations of simple well-established scientific control measures should be implemented urgently

    Dietary ω-6 polyunsaturated fatty acid arachidonic acid increases inflammation, but inhibits ECM protein expression in COPD

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    © 2018 The Author(s). Background: The obesity paradox in COPD describes protective effects of obesity on lung pathology and inflammation. However, the underlying relationships between obesity, diet and disease outcomes in COPD are not fully understood. In this study we measured the response to dietary fatty acids upon markers of inflammation and remodelling in human lung cells from people with and without COPD. Methods: Pulmonary fibroblasts were challenged with ω-3 polyunsaturated fatty acids (PUFAs), ω-6 PUFAs, saturated fatty acids (SFAs) or the obesity-associated cytokine TNFα. After 48-72 h release of the pro-inflammatory cytokines interleukin (IL)-6 and CXCL8 was measured using ELISA and mRNA expression and deposition of the extracellular matrix (ECM) proteins fibronectin, type I collagen, tenascin and perlecan were measured using qPCR or ECM ELISA, respectively. Results: Challenge with the ω-6 PUFA arachidonic acid (AA), but not ω-3 PUFAs or SFAs, resulted in increased IL-6 and CXCL8 release from fibroblasts, however IL-6 and CXCL8 release was reduced in COPD (n = 19) compared to non-COPD (n = 36). AA-induced cytokine release was partially mediated by downstream mediators of cyclooxygenase (COX)-2 in both COPD and non-COPD. In comparison, TNFα-induced IL-6 and CXCL8 release was similar in COPD and non-COPD, indicating a specific interaction of AA in COPD. In patients with or without COPD, regression analysis revealed no relationship between BMI and cytokine release. In addition, AA, but not SFAs or ω-3 PUFAs reduced the basal deposition of fibronectin, type I collagen, tenascin and perlecan into the ECM in COPD fibroblasts. In non-COPD fibroblasts, AA-challenge decreased basal deposition of type I collagen and perlecan, but not fibronectin and tenascin. Conclusions: This study shows that AA has disease-specific effects on inflammation and ECM protein deposition. The impaired response to AA in COPD might in part explain why obesity appears to have less detrimental effects in COPD, compared to other lung diseases

    Dietary fatty acids amplify inflammatory responses to infection through p38 MAPK signaling

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    Copyright © 2019 by the American Thoracic Society. Obesity is an important risk factor for severe asthma exacerbations, which are mainly caused by respiratory infections. Dietary fatty acids, which are increased systemically in obese patients and are further increased after high-fat meals, affect the innate immune system and may contribute to dysfunctional immune responses to respiratory infection. In this study we investigated the effects of dietary fatty acids on immune responses to respiratory infection in pulmonary fibroblasts and a bronchial epithelial cell line (BEAS-2B). Cells were challenged with BSA-conjugated fatty acids (v-6 polyunsaturated fatty acids [PUFAs], v-3 PUFAs, or saturated fatty acids [SFAs]) 1/2 the viral mimic polyinosinic:polycytidylic acid (poly[I:C]) or bacterial compound lipoteichoic acid (LTA), and release of proinflammatory cytokines was measured. In both cell types, challenge with arachidonic acid (AA) (v-6 PUFA) and poly(I:C) or LTA led to substantially greater IL-6 and CXCL8 release than either challenge alone, demonstrating synergy. In epithelial cells, palmitic acid (SFA) combined with poly(I:C) also led to greater IL-6 release. The underlying signaling pathways of AA and poly(I:C)- or LTA-induced cytokine release were examined using specific signaling inhibitors and IB. Cytokine production in pulmonary fibroblasts was prostaglandin dependent, and synergistic upregulation occurred via p38 mitogen-activated protein kinase signaling, whereas cytokine production in bronchial epithelial cell lines was mainly mediated through JNK and p38 mitogen-activated protein kinase signaling. We confirmed these findings using rhinovirus infection, demonstrating that AA enhances rhinovirus-induced cytokine release. This study suggests that during respiratory infection, increased levels of dietary v-6 PUFAs and SFAs may lead to more severe airway inflammation and may contribute to and/or increase the severity of asthma exacerbations

    Quality of life in Type 1 (insulin-dependent) diabetic patients prior to and after pancreas and kidney transplantation in relation to organ function

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    Improvement of the quality of life in Type 1 (insulin-dependent) diabetic patients with severe late complications is one of the main goals of pancreas and/or kidney grafting. To assess the influences of these treatment modalities on the different aspects of the quality of life a cross-sectional study in 157 patients was conducted. They were categorized into patients pre-transplant without dialysis (n=29; Group A), pre-transplant under dialysis (n=44; Group B), post-transplant with pancreas and kidney functioning (n=31; Group C), post-transplant with functioning kidney, but insulin therapy (n=29; Group D), post-transplant under dialysis and insulin therapy again (n=15; Group E) and patients after single pancreas transplantation and rejection, with good renal function, but insulin therapy (n=9; Group F). All patients answered a mailed, self-administered questionnaire (217 questions) consisting of a broad spectrum of rehabilitation criteria. The results indicate a better quality of life in Groups C and D as compared to the other groups. In general the scores are highest in C, but without any significant difference to D. Impressive significant differences between C or D and the other groups were found especially in their satisfaction with physical capacity, leisure-time activities or the overall quality of life. The satisfaction with the latter is highest in C (mean±SEM: 4.0±0.2 on a 1 to 5-rating scale; significantly different from A: 3.1±0.1, B: 2.7±0.2 and E: 2.6±0.3; p<0.01), followed by D (3.8±0.2; significantly different from B and E; p<0.01). Group F shows a mean of 3.1±0.4, which is not significantly different from C. The percentages of patients in each group, who are not working: A: 38 %, B: 64 %, C: 74 %, D: 66 %, E: 87 % and F: 78 % indicate that there is no marked improvement in the vocational situation after successful grafting

    Disease-associated gut microbiome and metabolome changes in patients with chronic obstructive pulmonary disease.

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    Chronic obstructive pulmonary disease (COPD) is the third commonest cause of death globally, and manifests as a progressive inflammatory lung disease with no curative treatment. The lung microbiome contributes to COPD progression, but the function of the gut microbiome remains unclear. Here we examine the faecal microbiome and metabolome of COPD patients and healthy controls, finding 146 bacterial species differing between the two groups. Several species, including Streptococcus sp000187445, Streptococcus vestibularis and multiple members of the family Lachnospiraceae, also correlate with reduced lung function. Untargeted metabolomics identifies a COPD signature comprising 46% lipid, 20% xenobiotic and 20% amino acid related metabolites. Furthermore, we describe a disease-associated network connecting Streptococcus parasanguinis_B with COPD-associated metabolites, including N-acetylglutamate and its analogue N-carbamoylglutamate. While correlative, our results suggest that the faecal microbiome and metabolome of COPD patients are distinct from those of healthy individuals, and may thus aid in the search for biomarkers for COPD

    Islands of conformational stability for Filopodia

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    Filopodia are long, thin protrusions formed when bundles of fibers grow outwardly from a cell surface while remaining closed in a membrane tube. We study the subtle issue of the mechanical stability of such filopodia and how this depends on the deformation of the membrane that arises when the fiber bundle adopts a helical configuration. We calculate the ground state conformation of such filopodia, taking into account the steric interaction between the membrane and the enclosed semiflexible fiber bundle. For typical filopodia we find that a minimum number of fibers is required for filopodium stability. Our calculation elucidates how experimentally observed filopodia can obviate the classical Euler buckling condition and remain stable up to several tens of . We briefly discuss how experimental observation of the results obtained in this work for the helical-like deformations of enclosing membrane tubes in filopodia could possibly be observed in the acrosomal reactions of the sea cucumber Thyone, and the horseshoe crab Limulus. Any realistic future theories for filopodium stability are likely to rely on an accurate treatment of such steric effects, as analysed in this work
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