OIM analysis of microstructure and texture of a TRIP assisted steel after static and dynamic deformation

TRIP-assisted steel with a composition of 0.2%C, 1.6%Mn, 1.5%Al was studied in the undeformed state, after the application of 10 and 30 % static tensile strain parallel to rolling the direction of the sheet and after dynamic (Hopkinson) fracture test. Detailed examination of the microstructure and microtexture by means of electron backscattered diffraction (EBSD) was carried out in order to quantify the microstructural constituents and to study the strain distribution. The microtexture evolution and the distribution of the specific texture components between the BCC and FCC phases were studied as a function of the external strain and the strain mode-static or dynamic. The strain localization and strain distribution between the structural constituents were quantified based on local misorientation maps. The full constraint Taylor model was used to predict the texture changes in the material and the results were compared to the experimental findings. Comparing the local misorientation data it was found that at low strains the ferrite accommodates approximately 10 times more deformation than the retained austenite. The strain localizes initially on the BCC-FCC phase boundaries and is then spread in the BCC constituents (ferrite and bainite) creating a deformation skeleton in the BCC phase. It was found that the observed texture changes in the measured retained austenite texture after deformation do not correspond exactly to the model prediction. The austenite texture components which were predicted by the Taylor model were not found in the measured austenite texture after deformation which means that they are first transformed to martensite, which is considered as an indication for the selective transformation of austenite under strain

Moving beyond the residential neighbourhood to explore social inequalities in exposure to area-level disadvantage: Results from the Interdisciplinary Study on Inequalities in Smoking

The focus, in place and health research, on a single, residential, context overlooks the fact that individuals are mobile and experience other settings in the course of their daily activities. Socioeconomic characteristics are associated with activity patterns, as well as with the quality of places where certain groups conduct activities, i.e. their non-residential activity space. Examining how measures of exposure to resources, and inequalities thereof, compare between residential and nonresidential contexts is required. Baseline data from 1,890 young adults (18 to 25 years-old) participating in the Interdisciplinary Study of Inequalities in Smoking, Montreal, Canada (2011- 2012), were analyzed. Socio-demographic and activity location data were collected using a validated, self-administered questionnaire. Area-level material deprivation was measured within 500-meter road-network buffer zones around participants’ residential and activity locations. Deprivation scores in the residential area and non-residential activity space were compared between social groups. Multivariate linear regression was used to estimate associations between individual- and area-level characteristics and non-residential activity space deprivation, and to explore whether these characteristics attenuated the education-deprivation association. Participants in low educational categories lived and conducted activities in more disadvantaged areas than university students/graduates. Educational inequalities in exposure to area-level deprivation were larger in the non-residential activity space than in the residential area for the least educated, but smaller for the intermediate group. Adjusting for selected covariates such as transportation resources and residential deprivation did not significantly attenuate the education-deprivation associations. Results support the existence of social isolation in residential areas and activity locations, whereby less educated individuals tend to be confined to more disadvantaged areas than their more educated counterparts. They also highlight the relevance of investigating both residential and non-residential contexts when studying inequalities in health-relevant exposures

Study of deformation texture in an AZ31 magnesium alloy rolled at wide range of rolling speed and reductions

Having the lowest density among all structural metals, magnesium has opened new horizons for developing commercial alloys with successful use in a wide variety of applications [1-2]. However, the plasticity of Mg is restricted at low temperatures because: (a) only a small number of deformation mechanisms can be activated [3-4], and (b) a preferred crystallographic orientation (texture) develops in wrought alloys, especially in flat-rolled sheets [5-7]. Therefore, manufacturing processes such as rolling and stamping should be performed at elevated temperatures [1, 8]. These barriers to the manufacturing process increase the price of magnesium wrought alloy products and limits the use of Mg to castings [9-10]. As a result, many studies have been conducted to improve formability by investigating the effect of manufacturing process. Therefore the current sheet production techniques, based on DC casting and hot rolling, are basically slow because the demand is easily met [11]. Twin roll casting followed by hot rolling appears to be processing route which can fulfil high volumes and reduced costs. The present authors succeeded in single-pass large draught rolling of various magnesium alloy sheets at low temperature (<473K) by high speed rolling [12]. Based on the data available in those works [13- 17], the sheet obtained by high-speed rolling exhibited a fine-grained microstructure (mean grain size of 2-3 μm), with good mechanical properties. For these advantages, the high speed rolling is a promising process to produce high-quality rolled magnesium alloy sheets at a low cost. For these advantages, the HSR is a promising process to produce high-quality rolled magnesium alloy sheets at a low cost. The goal of this research is thus to investigate the mechanisms responsible for the much higher rollability and the grain refinement after HSR. To do that, in this study, different rolling speeds from 15 to 1000 m/min were employed to twin rolled cast AZ31B magnesium alloy and different reductions

The added value of accounting for activity space when examining the association between tobacco retailer availability and smoking among young adults

Background: Despite a declining prevalence in many countries, smoking rates remain consistently high among young adults. Targeting contextual influences on smoking, such as the availability of tobacco retailers, is one promising avenue of intervention. Most studies have focused on residential or school neighbourhoods without accounting for other settings where individuals spend time, i.e., their activity space. We investigated the association between tobacco retailer availability in the residential neighbourhood and in the activity space and smoking status. Methods: Cross-sectional baseline data from 1,994 young adults (age 18-25) participating in the Interdisciplinary Study of Inequalities in Smoking (Montreal, Canada, 2011-2012) were analyzed. Residential and activity locations served to derive two measures of tobacco retailer availability: counts within 500-meter buffers and proximity to the nearest retailer. Prevalence ratios for the association between each tobacco retailer measure and smoking status were estimated using log-binomial regression. Results: Participants encountering high numbers of tobacco retailers in their residential neighbourhood, and both medium and high retailer counts in their activity space, were more likely to smoke compared to those exposed to fewer retailers. While residential proximity was not associated with smoking, we found 36% and 42% higher smoking prevalences among participants conducting activities within medium and high proximity to tobacco retailers compared to those conducting activities further from such outlets. Conclusion: This study adds to the sparse literature on contextual correlates of smoking among young adults, and illustrates the added value of considering individuals’ activity space in contextual studies of smoking

Economics of Chronic Diseases Protocol: Cost-effectiveness modelling and the future burden of non-communicable disease in Europe

Background: The majority of chronic disease is caused by risk factors which are mostly preventable. Effective interventions to reduce these risks are known and proven to be applicable to a variety of settings. Chronic disease is generally developed long before the fatal outcome, meaning that a lot of people spend a number of years in poor health. Effective prevention measures can prolong lives of individuals and significantly improve their quality of life. However, the methods to measure cost-effectiveness are a subject to much debate. The Economics of Chronic Diseases project aims to establish the best possible methods of measuring cost-effectiveness as well as develop micro-simulation models apt at projecting future burden of chronic diseases, their costs and potential savings after implementation of cost-effective interventions. Method: This research project will involve eight European countries: Bulgaria, Finland, Greece, Lithuania, The Netherlands, Poland, Portugal and the United Kingdom (UK). A literature review will be conducted to identify scientific articles which critically review the methods of cost-effectiveness. Contact will be made health economists to inform and enrich this review. This evidence will be used as a springboard for discussion at a meeting with key European stakeholders and experts with the aim of reaching a consensus on recommendations for cost-effectiveness methodology. Epidemiological data for coronary heart disease, chronic kidney disease, type 2 diabetes and chronic obstructive pulmonary disease will be collected along with data on time trends in three major risk factors related to these diseases, specifically tobacco consumption, blood pressure and body mass index. Economic and epidemiological micro-simulation models will be developed to asses the future distributions of risks, disease outcomes, healthcare costs and the cost-effectiveness of interventions to reduce the burden of chronic diseases in Europe. Discussion: This work will help to establish the best methods of measuring cost-effectiveness of health interventions as well as test a variety of scenarios to reduce the risk factors associated with selected chronic diseases. The modelling projections could be used to inform decisions and policies that will implement the best course of action to curb the rising incidence of chronic diseases.The EConDA project is supported by the European Commission Health Programme and the Executive Agency for Health and Consumers, grant agreement n0 20121213.www.econdaproject.e

Use of resuscitation promoting factors to screen for tuberculosis infection in household-exposed children in The Gambia.

BACKGROUND: Interferon-γ release assays (IGRA) with Resuscitation promoting factor (Rpf) proteins enhanced tuberculosis (TB) screening and diagnosis in adults but have not been evaluated in children. Children often develop paucibacillary TB and their immune response differs from that of adults, which together affect TB disease diagnostics and immunodiagnostics. We assessed the ability of Rpf to identify infection among household TB-exposed children in The Gambia and investigated their ability to discriminate Mycobacterium tuberculosis complex (MTBC) infection from active TB disease in children. METHODS: Detailed clinical investigations were done on 93 household TB-exposed Gambian children and a tuberculin skin test (TST) was administered to asymptomatic children. Venous blood was collected for overnight stimulation with ESAT-6/CFP-10-fusion protein (EC), purified protein derivative and RpfA, B, C, D and E. Interferon gamma (IFN-γ) production was measured by ELISA in supernatants and corrected for the background level. Infection status was defined by IGRA with EC and TB disease by mycobacterial confirmation and/or clinical diagnosis. We compared IFN-γ levels between infected and uninfected children and between infected and TB diseased children using a binomial logistic regression model while correcting for age and sex. A Receiver Operating Characteristics analysis was done to find the best cut-off for IFN-γ level and calculate sensitivity and specificity. RESULTS: Interferon gamma production was significantly higher in infected (IGRA+, n = 45) than in uninfected (IGRA-, n = 20) children after stimulation with RpfA, B, C, and D (P = 0.03; 0.007; 0.03 and 0.003, respectively). Using RpfB and D-specific IFN-γ cut-offs (33.9 pg/mL and 67.0 pg/mL), infection was classified with a sensitivity-specificity combination of 73-92% and 77-72% respectively, which was similar to and better than 65-75% for TST. Moreover, IFN-γ production was higher in infected than in TB diseased children (n = 28, 5 bacteriologically confirmed, 23 clinically diagnosed), following RpfB and D stimulation (P = 0.02 and 0.03, respectively). CONCLUSION: RpfB and RpfD show promising results for childhood MTBC infection screening, and both performed similar to and better than the TST in our study population. Additionally, both antigens appear to discriminate between infection and disease in children and thus warrant further investigation as screening and diagnostic antigens for childhood TB

Neutrophil activation and enhanced release of granule products in HIV-TB immune reconstitution inflammatory syndrome

Background: Tuberculosis immune reconstitution inflammatory syndrome (TB-IRIS) remains incompletely understood. Neutrophils are implicated in tuberculosis pathology but detailed investigations in TB-IRIS are lacking. We sought to further explore the biology of TB-IRIS and, in particular, the role of neutrophils. Setting: Two observational, prospective cohort studies in HIV/TB coinfected patients starting antiretroviral therapy (ART), 1 to analyze gene expression and subsequently 1 to explore neutrophil biology. Methods: nCounter gene expression analysis was performed in patients with TB-IRIS (n = 17) versus antiretroviral-treated HIV/TB coinfected controls without IRIS (n = 17) in Kampala, Uganda. Flow cytometry was performed in patients with TB-IRIS (n = 18) and controls (n = 11) in Cape Town, South Africa to determine expression of neutrophil surface activation markers, intracellular cytokines, and human neutrophil peptides (HNPs). Plasma neutrophil elastase and HNP1-3 were quantified using enzyme-linked immunosorbent assay. Lymph node immunohistochemistry was performed on 3 further patients with TB-IRIS. Results: There was a significant increase in gene expression of S100A9 (P = 0.002), NLRP12 (P = 0.018), COX-1 (P = 0.025), and IL-10 (P = 0.045) 2 weeks after ART initiation in Ugandan patients with TB-IRIS versus controls, implicating neutrophil recruitment. Patients with IRIS in both cohorts demonstrated increases in blood neutrophil count, plasma HNP and elastase concentrations from ART initiation to week 2. CD62L (L-selectin) expression on neutrophils increased over 4 weeks in South African controls whereas patients with IRIS demonstrated the opposite. Intense staining for the neutrophil marker CD15 and IL-10 was seen in necrotic areas of the lymph nodes of the patients with TB-IRIS. Conclusions: Neutrophils in TB-IRIS are activated, recruited to sites of disease, and release granule contents, contributing to pathology