Prediction of metal pm emission in rail tracks for condition monitoring application

Exposure to particulate material (PM) is a major health concern in megacities across the world which use trains as a primary public transport. PM emissions caused by railway traffic have hardly been investigated in the past, due to their obviously minor influence on the atmospheric air quality compared to automotive transport. However, the electrical train releases particles mainly originate from wear of rails track, brakes, wheels and carbon contact stripe which are the main causes of cardio-pulmonary and lung cancer. In previous reports most of the researchers have focused on case studies based PM emission investigation. However, the PM emission measured in this way doesn’t show separately the metal PM emission to the environment. In this study a generic PM emission model is developed using rail wheel-track wear model to quantify and characterise the metal emissions. The modelling has based on Archard’s wear model. The prediction models estimated the passenger train of one set emits 6.6mg/km-train at 60m/s speed. The effects of train speed on the PM emission has been also investigated and resulted in when the train speed increase the metal PM emission decrease. Using the model the metal PM emission has been studied for the train line between Leeds and Manchester to show potential emissions produced each day. This PM emission characteristics can be used to monitor the brakes, the wheels and the rail tracks conditions in future

A systematic review of internet-based worksite wellness approaches for cardiovascular disease risk management: outcomes, challenges & opportunities.

ContextThe internet is gaining popularity as a means of delivering employee-based cardiovascular (CV) wellness interventions though little is known about the cardiovascular health outcomes of these programs. In this review, we examined the effectiveness of internet-based employee cardiovascular wellness and prevention programs.Evidence acquisitionWe conducted a systematic review by searching PubMed, Web of Science and Cochrane library for all published studies on internet-based programs aimed at improving CV health among employees up to November 2012. We grouped the outcomes according to the American Heart Association (AHA) indicators of cardiovascular wellbeing--weight, BP, lipids, smoking, physical activity, diet, and blood glucose.Evidence synthesisA total of 18 randomized trials and 11 follow-up studies met our inclusion/exclusion criteria. Follow-up duration ranged from 6-24 months. There were significant differences in intervention types and number of components in each intervention. Modest improvements were observed in more than half of the studies with weight related outcomes while no improvement was seen in virtually all the studies with physical activity outcome. In general, internet-based programs were more successful if the interventions also included some physical contact and environmental modification, and if they were targeted at specific disease entities such as hypertension. Only a few of the studies were conducted in persons at-risk for CVD, none in blue-collar workers or low-income earners.ConclusionInternet based programs hold promise for improving the cardiovascular wellness among employees however much work is required to fully understand its utility and long term impact especially in special/at-risk populations

Sudden cardiac death in patients with ischemic heart failure undergoing coronary artery bypass grafting results from the STICH randomized clinical trial (Surgical Treatment for Ischemic Heart Failure)

Background—The risk of sudden cardiac death (SCD) in patients with heart failure following CABG has not been examined in a contemporary clinical trial of surgical revascularization. This analysis describes the incidence, timing and clinical predictors of SCD after CABG. Methods—Patients enrolled in the Surgical Treatment of Ischemic Heart Failure (STICH) trial who underwent CABG with or without surgical ventricular reconstruction (SVR) were included. We excluded patients with prior ICD and those randomized only to medical therapy. The primary outcome was SCD as adjudicated by a blinded committee. A Cox model was used to examine and identify predictors of SCD. The Fine and Gray method was used to estimate the incidence of SCD accounting for the competing risk of other deaths. Results—Over a median follow-up of 46 months, 113 patients of 1411 patients who received CABG without (n = 934) or with SVR (n = 477) had SCD; 311 died of other causes. The mean LVEF at enrollment was 28±9%. The 5-year cumulative incidence of SCD was 8.5%. Patients who had SCD and those who did not die were younger and had fewer comorbid conditions than those who died for reasons other than SCD. In the first 30 days after CABG, SCD (n=5) accounted for 7% of all deaths. The numerically greatest monthly rate of SCD was in the 31-90 day time period. In a multivariable analysis including baseline demographics, risk factors, coronary anatomy and LV function, ESVI and BNP were most strongly associated with SCD. Conclusions—The monthly risk of SCD shortly after CABG among patients with a low LVEF is highest between the first and third month, suggesting that risk stratification for SCD should occur early in the postoperative period, particularly in patients with increased preoperative ESVI and/or BNP

Radiative absorption enhancements by black carbon controlled by particle-to-particle heterogeneity in composition.

Black carbon (BC) absorbs solar radiation, leading to a strong but uncertain warming effect on climate. A key challenge in modeling and quantifying BC's radiative effect on climate is predicting enhancements in light absorption that result from internal mixing between BC and other aerosol components. Modeling and laboratory studies show that BC, when mixed with other aerosol components, absorbs more strongly than pure, uncoated BC; however, some ambient observations suggest more variable and weaker absorption enhancement. We show that the lower-than-expected enhancements in ambient measurements result from a combination of two factors. First, the often used spherical, concentric core-shell approximation generally overestimates the absorption by BC. Second, and more importantly, inadequate consideration of heterogeneity in particle-to-particle composition engenders substantial overestimation in absorption by the total particle population, with greater heterogeneity associated with larger model-measurement differences. We show that accounting for these two effects-variability in per-particle composition and deviations from the core-shell approximation-reconciles absorption enhancement predictions with laboratory and field observations and resolves the apparent discrepancy. Furthermore, our consistent model framework provides a path forward for improving predictions of BC's radiative effect on climate

Impurity states in the magnetic topological insulator V:(Bi,Sb)2_2Te3_3

The ferromagnetic topological insulator V:(Bi,Sb)$_2$Te$_3$ has been recently reported as a quantum anomalous Hall (QAH) system. Yet the microscopic origins of the QAH effect and the ferromagnetism remain unclear. One key aspect is the contribution of the V atoms to the electronic structure. Here the valence band of V:(Bi,Sb)$_2$Te$_3$ thin films was probed in an element-specific way by resonant photoemission spectroscopy. The signature of the V $3d$ impurity band was extracted, and exhibits a high density of states near Fermi level. First-principles calculations support the experimental results and indicate the coexistence of ferromagnetic superexchange and double exchange interactions. The observed impurity band is thus expected to contribute to the ferromagnetism via the interplay of different mechanisms.Comment: 5 pages, 3 figures, figure 3 changed, new references and discussion include

Peramorphosis, an evolutionary developmental mechanism in neotropical bat skull diversity

Background The neotropical leaf‐nosed bats (Chiroptera, Phyllostomidae) are an ecologically diverse group of mammals with distinctive morphological adaptations associated with specialized modes of feeding. The dramatic skull shape changes between related species result from changes in the craniofacial development process, which brings into focus the nature of the underlying evolutionary developmental processes. Results In this study, we use three‐dimensional geometric morphometrics to describe, quantify, and compare morphological modifications unfolding during evolution and development of phyllostomid bats. We examine how changes in development of the cranium may contribute to the evolution of the bat craniofacial skeleton. Comparisons of ontogenetic trajectories to evolutionary trajectories reveal two separate evolutionary developmental growth processes contributing to modifications in skull morphogenesis: acceleration and hypermorphosis. Conclusion These findings are consistent with a role for peramorphosis, a form of heterochrony, in the evolution of bat dietary specialists

Nurse staffing levels revisited: a consideration of key issues in nurse staffing levels and skill mix research.

AIM: This paper revisits the published evidence relating to how nurse staffing levels impact on patient, nurse and service outcomes and considers the implications of this body of research for nurse managers in their quest to determine optimum nursing numbers. BACKGROUND: Within the context of the recognized global nursing shortage and particular local pressures within international health services, questions of appropriate nurse staffing levels and skill mix are once again becoming increasingly important. It would seem that the determination of optimum nurse staffing levels and skill mix is a central issue in relation to health service governance, service user involvement, as well as in the recruitment, retention and well-being of nursing staff across the service sectors. METHODS: A review of published evidence was carried out, applying key principles of the systematic method, in order to facilitate the identification of current factors and issues in nurse staffing levels research. The review did not seek to address a specific research question. The search covered 10 years from 1998 to 2008 and identified more than 500 relevant papers, giving a wide international perspective. KEY ISSUES: The majority of research in the field relates to the acute service sector and there are considerable similarities in issues that transcend international boundaries. Much of the research focuses on the impact on patients and nurses of 'poor' nurse staffing levels. More recent studies have explored the impact of nurse staffing levels on the service organization itself. However, while there may be an association between models of nurse staffing and outcomes, there is insufficient evidence to establish a causal relationship between these factors. In this context it is perhaps time to reconsider how nursing outcomes are defined and measured. IMPLICATIONS FOR NURSING MANAGEMENT AND CONCLUSION: Nurse managers, commissioners of services and workforce planners need to be cognisant of key issues and analyses in the consideration of nurse staffing levels. Not least of these is the need for a healthy degree of caution regarding the supposed objectivity, scientific basis, or evidence base, for rational calculation of optimum nurse staffing levels

Incentives, Information, and Emergent Collective Accuracy

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93557/1/mde2560.pd