1,539 research outputs found

    A service oriented virtual environment for complex system analysis: Preliminary report

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    Distributed virtual simulation is a capability that is increasing in demand within the automotive manufacturing industry. The distributed and networked approach to system level design and simulation stands to benefit from a unifying relational oriented modeling and simulation framework due to the large number of simulation technologies that must be integrated. This will also permit innovative use of existing independent simulations for increased concurrency in design and verification and validation. Through relational orientation, high level syntax and semantics for representing models and simulations have been developed for proof of concept analysis. This paper presents an approach to drive a process of analysis of the vehicle as a complex system through the combination of a relational trade-off analysis framework and a distributed simulation execution delivered through a service-oriented integration architecture. This promises to provide a rigorous, traceable and agile approach to early stage conceptual vehicle design and analysis

    DIVIDER: Modelling and Evaluating Real-Time Service-Oriented Cyberphysical Co-Simulations

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    The ability to reliably distribute simulations across a distributed system and seamlessly integrate them as a workflow regardless of their level of abstraction is critical to improving the quality of product manufacturing. This paper presents the DIVIDER architecture for managing and maintaining real-time performance simulations integrated through SOAs. The described approach captures features present in complex workflow patterns such as asynchronous arbitrary cycles and estimates the worst case execution time in the context of the interfering execution environment

    Effects of Policies Designed to Keep Firearms from High-Risk Individuals

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    This article summarizes and critiques available evidence from studies published between 1999 and August 2014 on the effects of policies designed to keep firearms from high-risk individuals in the United States. Some prohibitions for high-risk individuals (e.g., those under domestic violence restraining orders, violent misdemeanants) and procedures for checking for more types of prohibiting conditions are associated with lower rates of violence. Certain laws intended to prevent prohibited persons from accessing firearms -- rigorous permit-to-purchase, comprehensive background checks, strong regulation and oversight of gun dealers, and requiring gun owners to promptly report lost or stolen firearms -- are negatively associated with the diversion of guns to criminals. Future research is needed to examine whether these laws curtail nonlethal gun violence and whether the effects of expanding prohibiting conditions for firearm possession are modified by the presence of policies to prevent diversion

    Focused Deterrence and the Prevention of Violent Gun Injuries: Practice, Theoretical Principles, and Scientific Evidence

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    Focused deterrence strategies are a relatively new addition to a growing portfolio of evidence-based violent gun injury prevention practices available to policy makers and practitioners. These strategies seek to change offender behavior by understanding the underlying violence-producing dynamics and conditions that sustain recurring violent gun injury problems and by implementing a blended strategy of law enforcement, community mobilization, and social service actions. Consistent with documented public health practice, the focused deterrence approach identifies underlying risk factors and causes of recurring violent gun injury problems, develops tailored responses to these underlying conditions, and measures the impact of implemented interventions. This article reviews the practice, theoretical principles, and evaluation evidence on focused deterrence strategies. Although more rigorous randomized studies are needed, the available empirical evidence suggests that these strategies generate noteworthy gun violence reduction impacts and should be part of a broader portfolio of violence prevention strategies available to policy makers and practitioners

    Clinical implementation of a knowledge based planning tool for prostate VMAT

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    Abstract Background A knowledge based planning tool has been developed and implemented for prostate VMAT radiotherapy plans providing a target average rectum dose value based on previously achievable values for similar rectum/PTV overlap. The purpose of this planning tool is to highlight sub-optimal clinical plans and to improve plan quality and consistency. Methods A historical cohort of 97 VMAT prostate plans was interrogated using a RayStation script and used to develop a local model for predicting optimum average rectum dose based on individual anatomy. A preliminary validation study was performed whereby historical plans identified as “optimal” and “sub-optimal” by the local model were replanned in a blinded study by four experienced planners and compared to the original clinical plan to assess whether any improvement in rectum dose was observed. The predictive model was then incorporated into a RayStation script and used as part of the clinical planning process. Planners were asked to use the script during planning to provide a patient specific prediction for optimum average rectum dose and to optimise the plan accordingly. Results Plans identified as “sub-optimal” in the validation study observed a statistically significant improvement in average rectum dose compared to the clinical plan when replanned whereas plans that were identified as “optimal” observed no improvement when replanned. This provided confidence that the local model can identify plans that were suboptimal in terms of rectal sparing. Clinical implementation of the knowledge based planning tool reduced the population-averaged mean rectum dose by 5.6Gy. There was a small but statistically significant increase in total MU and femoral head dose and a reduction in conformity index. These did not affect the clinical acceptability of the plans and no significant changes to other plan quality metrics were observed. Conclusions The knowledge-based planning tool has enabled substantial reductions in population-averaged mean rectum dose for prostate VMAT patients. This suggests plans are improved when planners receive quantitative feedback on plan quality against historical data

    Factors Affecting a Recently Purchased Handgun’s Risk for Use in Crime under Circumstances That Suggest Gun Trafficking

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    While many handguns are used in crime each year in the USA, most are not. We conducted this study to identify factors present at the time of a handgun’s most recent retail sale that were associated with its subsequent use in crime under circumstances suggesting that the handgun had been trafficked—purchased with the intent of diverting it to criminal use. Handguns acquired in multiple-gun purchases were of particular interest. Using data for 180,321 handguns purchased from federally licensed retailers in California in 1996, we studied attributes of the handguns, the retailers selling them, the purchasers, and the sales transactions. Our outcome measure was a handgun’s recovery by a police agency, followed by a gun ownership trace, conducted by the Bureau of Alcohol, Tobacco, Firearms and Explosives, that determined (a) that the recovery had occurred within 3 years of the handgun’s most recent purchase from a licensed retailer and (b) that the person who possessed the gun when it was recovered by police was not its most recent purchaser. Altogether, 722 handguns were recovered and had trace results that met the additional criteria. Handguns acquired in multiple-gun, same-day transactions were more likely to be traced than were single-purchase handguns (odds ratio [OR] 1.33, 95% confidence intervals [CI] 1.08 to 1.63). This was not the case for multiple-purchase handguns defined more broadly as multiple handguns purchased by one individual over any 30-day period as used in “one-gun-a-month” laws. Bivariate regressions indicated increased risk of a handgun being traced when it sold new for $150 or less (OR 4.28, 95% CI 3.59 to 5.11) or had been purchased by a woman (OR 2.02, 95% CI 1.62 to 2.52). Handguns sold by retailers who also had a relatively high proportion (≥2%) of purchases denied because the prospective purchasers were prohibited from owning firearms were more likely to be traced than were those sold by other retailers (OR 4.09, 95% CI 3.39 to 4.94). These findings persisted in multivariate analyses. Our findings suggest specific strategies for intervention to prevent gun violence

    Barriers and enablers to salt intake reduction in Australian adults with high blood pressure.

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    High dietary salt intake is a known risk factor for hypertension. However, Australians continue to consume excessive amounts of salt. The purpose of this study was to identify barriers, enablers and strategies to reduce salt in a sample of Australian adults with hypertension. This was a qualitative study. Participants were asked a set of open-ended questions during focus groups conducted between October 2020 and April 2021. Sessions were recorded and transcribed. Using an inductive approach, the transcript data from the focus groups were thematically analysed. This involved checking accuracy, becoming familiar with the data, coding responses based on questions, identifying themes through common patterns and validating themes by grouping similar questions that represented the data and study aim effectively. Thirty-one adults (55 % females) with high blood pressure participated in the focus group discussions. Participants demonstrated good knowledge of high blood pressure risk factors but lacked an understanding of recommended salt intake levels and sources of hidden salt. Challenges in reducing salt intake included the limited availability of low-salt commercial foods. Participants suggested improved food labelling and the use of technology-based interventions to promote healthier choices. Findings highlight the need for behavioural interventions, policy reforms and collaborations between the government, food industries and health organisations to address high salt intake in the population

    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

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    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

    Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector

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    The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV

    Tumour seeding in the tract of percutaneous renal tumour biopsy: A report on seven cases from a UK tertiary referral centre

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    The role of percutaneous renal tumour biopsy (RTB) in the management of radiological indeterminate renal masses is long established. Patients with small renal masses who have biopsy-proven renal cell carcinoma (RCC) may be offered surgery, ablative therapy, or active surveillance, and RTB can provide diagnostic tissue from patients with metastatic disease who might benefit from systemic therapy. Current guidelines suggest that tumour seeding along the needle tract is anecdotal, but several cases have been reported recently, although some have been associated with lack of a coaxial sheath. We report on seven patients who underwent surgical resection of RCC in our tertiary referral institution following diagnostic RTB between 2014 and 2017 for whom RTB tract seeding by tumour was identified on histological examination of the resection specimen. One of these patients subsequently developed local tumour recurrence at the site of the previous biopsy
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