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

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

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

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

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

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

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

A review of Ireland's waterbirds, with emphasis on wintering migrants and reference to H5N1 avian influenza

Ireland is characterised by its diversity and large abundance of wetlands, making it attractive to a wide variety of waterbirds throughout the year. This paper presents an overview of Ireland's waterbirds, including ecological factors relevant to the potential introduction, maintenance, transmission and spread of infectious agents, including the H5N1 avian influenza virus, in Ireland. Particular emphasis is placed on five groups of wintering migrants (dabbling and sieving wildfowl, grazing wildfowl, diving wildfowl, waders and gulls), noting that the H5N1 avian influenza virus has mainly been isolated from this subset of waterbirds. Ireland's wetlands are visited during the spring and summer months by hundreds of thousands of waterbirds which come to breed, predominantly from southern latitudes, and during the autumn and winter by waterbirds which come from a variety of origins (predominantly northern latitudes), and which are widely distributed and often congregate in mixed-species flocks. The distribution, feeding habits and social interactions of the five groups of wintering migrants are considered in detail. Throughout Ireland, there is interaction between different waterbird populations (breeding migrants, the wintering migrants and resident waterbird populations). There is also a regular and complex pattern of movement between feeding and roosting areas, and between wetlands and farmland. These interactions are likely to facilitate the rapid transmission and spread of the H5N1 avian influenza virus, if it were present in Ireland

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

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

Observed Reductions in Schistosoma mansoni Transmission from Large-Scale Administration of Praziquantel in Uganda: A Mathematical Modelling Study

To date schistosomiasis control programmes based on chemotherapy have largely aimed at controlling morbidity in treated individuals rather than at suppressing transmission. In this study, a mathematical modelling approach was used to estimate reductions in the rate of Schistosoma mansoni reinfection following annual mass drug administration (MDA) with praziquantel in Uganda over four years (2003-2006). In doing this we aim to elucidate the benefits of MDA in reducing community transmission.Age-structured models were fitted to a longitudinal cohort followed up across successive rounds of annual treatment for four years (Baseline: 2003, TREATMENT: 2004-2006; n = 1,764). Instead of modelling contamination, infection and immunity processes separately, these functions were combined in order to estimate a composite force of infection (FOI), i.e., the rate of parasite acquisition by hosts.MDA achieved substantial and statistically significant reductions in the FOI following one round of treatment in areas of low baseline infection intensity, and following two rounds in areas with high and medium intensities. In all areas, the FOI remained suppressed following a third round of treatment.This study represents one of the first attempts to monitor reductions in the FOI within a large-scale MDA schistosomiasis morbidity control programme in sub-Saharan Africa. The results indicate that the Schistosomiasis Control Initiative, as a model for other MDA programmes, is likely exerting a significant ancillary impact on reducing transmission within the community, and may provide health benefits to those who do not receive treatment. The results obtained will have implications for evaluating the cost-effectiveness of schistosomiasis control programmes and the design of monitoring and evaluation approaches in general

Dynamic self-assembly of DNA minor groove-binding ligand DB921 into nanotubes triggered by an alkali halide.

We describe a novel self-assembling supramolecular nanotube system formed by a heterocyclic cationic molecule which was originally designed for its potential as an antiparasitic and DNA sequence recognition agent. Our structural characterisation work indicates that the nanotubes form via a hierarchical assembly mechanism that can be triggered and tuned by well-defined concentrations of simple alkali halide salts in water. The nanotubes assembled in NaCl have inner and outer diameters of ca. 22 nm and 26 nm respectively, with lengths that reach into several microns. Our results suggest the tubes consist of DB921 molecules stacked along the direction of the nanotube long axis. The tubes are stabilised by face-to-face π-π stacking and ionic interactions between the charged amidinium groups of the ligand and the negative halide ions. The assembly process of the nanotubes was followed using small-angle X-ray and neutron scattering, transmission electron microscopy and ultraviolet/visible spectroscopy. Our data demonstrate that assembly occurs through the formation of intermediate ribbon-like structures that in turn form helices that tighten and compact to form the final stable filament. This assembly process was tested using different alkali-metal salts, showing a strong preference for chloride or bromide anions and with little dependency on the type of cation. Our data further demonstrates the existence of a critical anion concentration above which the rate of self-assembly is greatly enhanced

Manipulation of structure and optoelectronic properties through bromine inclusion in a layered lead bromide perovskite

Funding: UK Research and Innovation - MR/T022094/1; Engineering and Physical Sciences Research Council - EP/V034138/1, EP/R023751/1, EP/T019298/1; Carnegie Trust for the Universities of Scotland - RIG008653.One of the great advantages of organic–inorganic metal halides is that their structures and properties are highly tuneable and this is important when optimizing materials for photovoltaics or other optoelectronic devices. One of the most common and effective ways of tuning the electronic structure is through anion substitution. Here, we report the inclusion of bromine into the layered perovskite [H3N(CH2)6NH3]PbBr4 to form [H3N(CH2)6NH3]PbBr4·Br2, which contains molecular bromine (Br2) intercalated between the layers of corner-sharing PbBr6 octahedra. Bromine intercalation in [H3N(CH2)6NH3]PbBr4·Br2 results in a decrease in the band gap of 0.85 eV and induces a structural transition from a Ruddlesden–Popper-like to Dion–Jacobson-like phase, while also changing the conformation of the amine. Electronic structure calculations show that Br2 intercalation is accompanied by the formation of a new band in the electronic structure and a significant decrease in the effective masses of around two orders of magnitude. This is backed up by our resistivity measurements that show that [H3N(CH2)6NH3]PbBr4·Br2 has a resistivity value of one order of magnitude lower than [H3N(CH2)6NH3]PbBr4, suggesting that bromine inclusion significantly increases the mobility and/or carrier concentration in the material. This work highlights the possibility of using molecular inclusion as an alternative tool to tune the electronic properties of layered organic–inorganic perovskites, while also being the first example of molecular bromine inclusion in a layered lead halide perovskite. By using a combination of crystallography and computation, we show that the key to this manipulation of the electronic structure is the formation of halogen bonds between the Br2 and Br in the [PbBr4]∞ layers, which is likely to have important effects in a range of organic–inorganic metal halides.Publisher PDFPeer reviewe