857 research outputs found

    Applications of GridProbe technology for traffic monitoring on high-capacity backbone networks, data-link layer simulation approach

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    This paper covers the on-going research on MASTSproject. The project objectives are to set-up and exploit a trafficmonitoring system for the UKLIGHT international high capacityexperimental network. The proposed system will record data flowand topological information at a range of time scales (fromfractions of a second to years). It will make this informationavailable to the community as a web service and managementinterfaces. In this paper the focus is on development of simulationplatforms that enable testing the analysis algorithms and Webservices output

    Comparison of dimensional accuracies of stereolithography and powder binder printing

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    This paper presents a comparative experimental investigation of the dimensional accuracies of two widely used rapid prototyping (RP) processes: stereolithography (SLA) and powder binder printing (PBP). Four replicates of a purpose-designed component using each RP process were fabricated, and the measurements of the internal and external features of all surfaces were performed using a general-purpose coordinate measurement machine. The results showed that in both cases, the main cause of dimensional variations was the volumetric change inherent in the process. The precision of SLA was far better than that of PBP. The dimensional accuracy of SLA was better in the z direction, whereas PBP produced better dimensional accuracy in the x–y plane. In both RP processes, the height error consisted of two components: constant error and cumulative error. The constant error component was equal to the datum surface error. SLA yielded an average datum surface error that was 68 % higher than in PBP. The height error of SLA improved with the increase in nominal height, whereas it deteriorated in PBP

    Further investigation of confirmed urinary tract infection (UTI) in children under five years: a systematic review.

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    Background: Further investigation of confirmed UTI in children aims to prevent renal scarring and future complications. Methods: We conducted a systematic review to determine the most effective approach to the further investigation of confirmed urinary tract infection (UTI) in children under five years of age. Results: 73 studies were included. Many studies had methodological limitations or were poorly reported. Effectiveness of further investigations: One study found that routine imaging did not lead to a reduction in recurrent UTIs or renal scarring. Diagnostic accuracy: The studies do not support the use of less invasive tests such as ultrasound as an alternative to renal scintigraphy, either to rule out infection of the upper urinary tract (LR- = 0.57, 95%CI: 0.47, 0.68) and thus to exclude patients from further investigation or to detect renal scarring (LR+ = 3.5, 95% CI: 2.5, 4.8). None of the tests investigated can accurately predict the development of renal scarring. The available evidence supports the consideration of contrast-enhanced ultrasound techniques for detecting vesico-ureteric reflux (VUR), as an alternative to micturating cystourethrography (MCUG) (LR+ = 14.1, 95% CI: 9.5, 20.8; LR- = 0.20, 95%CI: 0.13, 0.29); these techniques have the advantage of not requiring exposure to ionising radiation. Conclusion: There is no evidence to support the clinical effectiveness of routine investigation of children with confirmed UTI. Primary research on the effectiveness, in terms of improved patient outcome, of testing at all stages in the investigation of confirmed urinary tract infection is urgently required

    Different genes interact with particulate matter and tobacco smoke exposure in affecting lung function decline in the general population

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    BACKGROUND: Oxidative stress related genes modify the effects of ambient air pollution or tobacco smoking on lung function decline. The impact of interactions might be substantial, but previous studies mostly focused on main effects of single genes. OBJECTIVES: We studied the interaction of both exposures with a broad set of oxidative-stress related candidate genes and pathways on lung function decline and contrasted interactions between exposures. METHODS: For 12679 single nucleotide polymorphisms (SNPs), change in forced expiratory volume in one second (FEV(1)), FEV(1) over forced vital capacity (FEV(1)/FVC), and mean forced expiratory flow between 25 and 75% of the FVC (FEF(25-75)) was regressed on interval exposure to particulate matter >10 microm in diameter (PM10) or packyears smoked (a), additive SNP effects (b), and interaction terms between (a) and (b) in 669 adults with GWAS data. Interaction p-values for 152 genes and 14 pathways were calculated by the adaptive rank truncation product (ARTP) method, and compared between exposures. Interaction effect sizes were contrasted for the strongest SNPs of nominally significant genes (p(interaction)>0.05). Replication was attempted for SNPs with MAF<10% in 3320 SAPALDIA participants without GWAS. RESULTS: On the SNP-level, rs2035268 in gene SNCA accelerated FEV(1)/FVC decline by 3.8% (p(interaction) = 2.5x10(-6)), and rs12190800 in PARK2 attenuated FEV1 decline by 95.1 ml p(interaction) = 9.7x10(-8)) over 11 years, while interacting with PM10. Genes and pathways nominally interacting with PM10 and packyears exposure differed substantially. Gene CRISP2 presented a significant interaction with PM10 (p(interaction) = 3.0x10(-4)) on FEV(1)/FVC decline. Pathway interactions were weak. Replications for the strongest SNPs in PARK2 and CRISP2 were not successful. CONCLUSIONS: Consistent with a stratified response to increasing oxidative stress, different genes and pathways potentially mediate PM10 and tobac smoke effects on lung function decline. Ignoring environmental exposures would miss these patterns, but achieving sufficient sample size and comparability across study samples is challengin

    Political Regimes and Sovereign Credit Risk in Europe, 1750-1913

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    This article uses a new panel data set to perform a statistical analysis of political regimes and sovereign credit risk in Europe from 1750 to 1913. Old Regime polities typically suffered from fiscal fragmentation and absolutist rule. By the start of World War I, however, many such countries had centralized institutions and limited government. Panel regressions indicate that centralized and?or limited regimes were associated with significant improvements in credit risk relative to fragmented and absolutist ones. Structural break tests also reveal close relationships between major turning points in yield series and political transformations

    An analysis of potential barriers and enablers to regulating the television marketing of unhealthy foods to children at the state government level in Australia

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    Background In Australia there have been many calls for government action to halt the effects of unhealthy food marketing on children\u27s health, yet implementation has not occurred. The attitudes of those involved in the policy-making process towards regulatory intervention governing unhealthy food marketing are not well understood. The objective of this research was to understand the perceptions of senior representatives from Australian state and territory governments, statutory authorities and non-government organisations regarding the feasibility of state-level government regulation of television marketing of unhealthy food to children in Australia.Method Data from in-depth semi-structured interviews with senior representatives from state and territory government departments, statutory authorities and non-government organisations (n=22) were analysed to determine participants\u27 views about regulation of television marketing of unhealthy food to children at the state government level. Data were analysed using content and thematic analyses.Results Regulation of television marketing of unhealthy food to children was supported as a strategy for obesity prevention. Barriers to implementing regulation at the state level were: the perception that regulation of television advertising is a Commonwealth, not state/territory, responsibility; the power of the food industry and; the need for clear evidence that demonstrates the effectiveness of regulation. Evidence of community support for regulation was also cited as an important factor in determining feasibility.Conclusions The regulation of unhealthy food marketing to children is perceived to be a feasible strategy for obesity prevention however barriers to implementation at the state level exist. Those involved in state-level policy making generally indicated a preference for Commonwealth-led regulation. This research suggests that implementation of regulation of the television marketing of unhealthy food to children should ideally occur under the direction of the Commonwealth government. However, given that regulation is technically feasible at the state level, in the absence of Commonwealth action, states/territories could act independently. The relevance of our findings is likely to extend beyond Australia as unhealthy food marketing to children is a global issue.<br /

    Aerosolized amikacin for treatment of pulmonary Mycobacterium avium infections: an observational case series

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    BACKGROUND: Current systemic therapy for nontuberculous mycobacterial pulmonary infection is limited by poor clinical response rates, drug toxicities and side effects. The addition of aerosolized amikacin to standard oral therapy for nontuberculous mycobacterial pulmonary infection may improve treatment efficacy without producing systemic toxicity. This study was undertaken to assess the safety, tolerability and preliminary clinical benefits of the addition of aerosolized amikacin to a standard macrolide-based oral treatment regimen. CASE PRESENTATIONS: Six HIV-negative patients with Mycobacterium avium intracellulare pulmonary infections who had failed standard therapy were administered aerosolized amikacin at 15 mg/kg daily in addition to standard multi-drug macrolide-based oral therapy. Patients were monitored clinically and serial sputum cultures were obtained to assess response to therapy. Symptomatic improvement with radiographic stabilization and eradication of mycobacterium from sputum were considered markers of success. Of the six patients treated with daily aerosolized amikacin, five responded to therapy. All of the responders achieved symptomatic improvement and four were sputum culture negative after 6 months of therapy. Two patients became re-infected with Mycobacterium avium intracellulare after 7 and 21 months of treatment. One of the responders who was initially diagnosed with Mycobacterium avium intracellulare became sputum culture positive for Mycobacterium chelonae resistant to amikacin after being on intermittent therapy for 4 years. One patient had progressive respiratory failure and died despite additional therapy. There was no evidence of nephrotoxicity or ototoxicity associated with therapy. CONCLUSION: Aerosolized delivery of amikacin is a promising adjunct to standard therapy for pulmonary nontuberculous mycobacterial infections. Larger prospective trials are needed to define its optimal role in therapy of this disease

    Identification of Small Molecule Lead Compounds for Visceral Leishmaniasis Using a Novel Ex Vivo Splenic Explant Model System

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    Visceral leishmaniasis is a life threatening parasitic disease present in several countries of the world. New drugs are needed to treat this disease because treatments are becoming increasingly ineffective. We established a novel system to screen for new anti-leishmanial compounds that utilizes spleen cells from hamsters infected with the parasite Leishmania donovani. The parasite strain we used was genetically engineered to emit light by the incorporation of the firefly luciferase gen. This laboratory test system has the advantage of reproducing the cellular environment where the drug has to combat the infection. The efficacy of the compounds is easily determined by measuring the light emitted by the surviving parasites in a luminometer after exposing the infected cells to the test compounds. The screening of more than 4,000 molecules showed that 84 (2.1%) of them showed anti-leishmanial activity and had an acceptable toxicity evaluation. Eighty two percent of these molecules, which had varied chemical structures, were previously unknown to have anti-leishmanial activity. Further studies in animals of these new chemical entities may identify drug candidates for the treatment of visceral leishmaniasis

    Elimination of visceral leishmaniasis in the Indian subcontinent: a comparison of predictions from three transmission models.

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    We present three transmission models of visceral leishmaniasis (VL) in the Indian subcontinent (ISC) with structural differences regarding the disease stage that provides the main contribution to transmission, including models with a prominent role of asymptomatic infection, and fit them to recent case data from 8 endemic districts in Bihar, India. Following a geographical cross-validation of the models, we compare their predictions for achieving the WHO VL elimination targets with ongoing treatment and vector control strategies. All the transmission models suggest that the WHO elimination target (<1 new VL case per 10,000 capita per year at sub-district level) is likely to be met in Bihar, India, before or close to 2020 in sub-districts with a pre-control incidence of 10 VL cases per 10,000 people per year or less, when current intervention levels (60% coverage of indoor residual spraying (IRS) of insecticide and a delay of 40days from onset of symptoms to treatment (OT)) are maintained, given the accuracy and generalizability of the existing data regarding incidence and IRS coverage. In settings with a pre-control endemicity level of 5/10,000, increasing the effective IRS coverage from 60 to 80% is predicted to lead to elimination of VL 1-3 years earlier (depending on the particular model), and decreasing OT from 40 to 20days to bring elimination forward by approximately 1year. However, in all instances the models suggest that L. donovani transmission will continue after 2020 and thus that surveillance and control measures need to remain in place until the longer-term aim of breaking transmission is achieved
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