'If I cannot access services then there is no reason for me to test': the impact of health service charges on HIV testing and treatment amongst migrants in England

Policy governing entitlement to access government health care for foreign nationals in England is a subject of debate, controversy and confusion. Of particular concern to health providers has been the impact of National Health Service charges on delaying HIV testing and anti-retroviral treatment uptake and adherence amongst certain migrant groups. Data obtained through focus groups with 70 migrants from southern Africa, suggest that confusion over health care entitlements exists amongst those seeking health care and is reported amongst health service providers. This confusion, as well as financial difficulties and fears over deportation facing some migrants, can in turn be a factor influencing their decisions to avoid formal health services, resort to alternative and often ineffective or potentially adverse forms of therapy, and delay HIV testing and treatment uptake

Advanced Ceramics for Use as Fuel Element Materials in Nuclear Thermal Propulsion Systems

With the recent start (October 2011) of the joint National Aeronautics and Space Administration (NASA) and Department of Energy (DOE) Advanced Exploration Systems (AES) Nuclear Cryogenic Propulsion Stage (NCPS) Program, there is renewed interest in developing advanced ceramics for use as fuel element materials in nuclear thermal propulsion (NTP) systems. Three classes of fuel element materials are being considered under the NCPS Program: (a) graphite composites - consisting of coated graphite elements containing uranium carbide (or mixed carbide), (b) cermets (ceramic/metallic composites) - consisting of refractory metal elements containing uranium oxide, and (c) advanced carbides consisting of ceramic elements fabricated from uranium carbide and one or more refractory metal carbides [1]. The current development effort aims to advance the technology originally developed and demonstrated under Project Rover (1955-1973) for the NERVA (Nuclear Engine for Rocket Vehicle Application) [2]

Overview of C/C-SiC Composite Development for the Orion Launch Abort System

Past and present efforts by the authors to further understanding of the ceramic matrix composite (CMC) material used in the valve components of the Orion Launch Abort System (LAS) Attitude Control Motor (ACM) will be presented. The LAS is designed to quickly lift the Orion Crew Exploration Vehicle (CEV) away from its launch vehicle in emergency abort scenarios. The ACM is a solid rocket motor which utilizes eight throttleable nozzles to maintain proper orientation of the CEV during abort operations. Launch abort systems have not been available for use by NASA on manned launches since the last Apollo ]Saturn launch in 1975. The CMC material, carbon-carbon/silicon-carbide (C/C-SiC), is manufactured by Fiber Materials, Inc. and consists of a rigid 4-directional carbon-fiber tow weave reinforced with a mixed carbon plus SiC matrix. Several valve and full system (8-valve) static motor tests have been conducted by the motor vendor. The culmination of these tests was the successful flight test of the Orion LAS Pad Abort One (PA ]1) vehicle on May 6, 2010. Due to the fast pace of the LAS development program, NASA Marshall Space Flight Center assisted the LAS community by performing a series of material and component evaluations using fired hardware from valve and full ]system development motor tests, and from the PA-1 flight ACM motor. Information will be presented on the structure of the C/C-SiC material, as well as the efficacy of various non ]destructive evaluation (NDE) techniques, including but not limited to: radiography, computed tomography, nanofocus computed tomography, and X-ray transmission microscopy. Examinations of the microstructure of the material via scanning electron microscopy and energy dispersive spectroscopy will also be discussed. The findings resulting from the subject effort are assisting the LAS Project in risk assessments and in possible modifications to the final ACM operational design

MSFC Thermal Protection System Materials on MISSE-6

The Lightweight Nonmetallic Thermal Protection Materials Technology (LNTPMT) program studied a number of ceramic matrix composites, ablator materials, and tile materials for durability in simulated space environment. Materials that indicated low atomic oxygen reactivity and negligible change in thermo-optical properties in ground testing were selected to fly on the Materials on International Space Station Experiment (MISSE)-6. These samples were exposed for 17 months to the low Earth orbit environment on both the ram and wake sides of MISSE-6B. Thermo-optical properties are discussed, along with any changes in mass

Increased severity of glomerulonephritis in C-C chemokine receptor 2 knockout mice

Increased severity of glomerulonephritis in C-C chemokine receptor 2 knockout mice.BackgroundThe C-C chemokine receptor 2 (CCR2) is expressed on monocytes and facilitates monocyte migration. CCR2 is a prominent receptor for monocyte chemoattractant protein-1 (MCP-1). This chemokine recruits monocytes to sites of inflammation. It has been suggested that CCR2 and its ligand, MCP-1, play a role in the pathogenesis of glomerulonephritis. The goal of this study was to determine the contribution of CCR2 in a murine model of accelerated nephrotoxic nephritis. We measured the extent of development of renal disease in CCR2 wild-type and knockout mice after the administration of antiglomerular basement membrane antibody.MethodsEight groups of animals were treated (N = 10 per group). Four days after IgG immunization, CCR2 wild-type and knockout mice received control serum or nephrotoxic serum. The urinary protein/creatinine ratio was measured on days 1 and 3; plasma and kidneys were collected on days 4 and 7. Kidneys were evaluated by light microscopy, immunohistochemistry, and immunofluorescence. The genotype of mice was confirmed by tissue analysis.ResultsProtective effects of CCR2 knockout on the urinary protein/creatinine ratio were observed on day 1, as values for this parameter were significantly lower (35 ± 3.6) than in nephritic wild-type mice (50 ± 6.8). There was a marked increase in proteinuria in nephritic wild-type mice on day 1 compared with vehicle-treated, wild-type animals (5 ± 1.0). On day 3, the ameliorative effects of CCR2 knockout were not observed; the increase in the urinary protein/creatinine ratio was similar in nephritic CCR2 wild-type (92 ± 11.2) and knockout mice (102 ± 9.2). Plasma markers of disease were evaluated on days 4 and 7. At these time points, there were no beneficial effects of CCR2 receptor knockout on plasma levels of urea nitrogen, creatinine, albumin, or cholesterol. On day 7, blood urea nitrogen (248 ± 19.9 mg/dL) and plasma cholesterol were higher in nephritic CCR2 knockout mice than in wild-type mice (142 ± 41.7 mg/dL) that received nephrotoxic serum. Histopathologic injury was more severe in nephritic CCR2 knockout mice than nephritic wild-type mice on day 4 (3.1 ± 0.3 vs. 2.0 ± 0.3) and day 7 (3.6 ± 0.2 vs. 2.9 ± 0.3). By immunohistochemical analysis at day 4, there were significantly fewer mac-2–positive cells, representative of macrophages in the glomeruli of nephritic CCR2 knockout (2.1 ± 0.6) mice than nephritic wild-type (3.9 ± 0.5) animals. By indirect immunofluorescence, there was a moderate, diffuse linear IgG deposition of equivalent severity present in glomeruli of both wild-type and CCR2 knockout nephritic mice.ConclusionThese results suggest that our strategy was successful in reducing macrophage infiltration, but this model of glomerulonephritis is not solely dependent on the presence of CCR2 for progression of disease. After a transient ameliorative effect on proteinuria, CCR2 knockout led to more severe injury in nephritic mice. This raises the intriguing possibility that a CCR2 gene product ameliorates glomerulonephritis in this murine model. Although effects that occur in chemokine knockout mice are not equivalent to those expected with prolonged use of a chemokine antagonist, this study may nevertheless have implications for consideration of long-term use of chemokine antagonists in renal disease

Face processing: human perception and principal components analysis

Principal component analysis (PCA) of face images is here related to subjects' performance on the same images. In two experiments subjects were shown a set of faces and asked to rate them for distinctiveness. They were subsequently shown a superset of faces and asked to identify those which appeared originally. Replicating previous work, we found that hits and false positives (FPs) did not correlate: those faces easy to identify as being "seen" were unrelated to those faces easy to reject as being "unseen". PCA was performed on three data sets: (i) face images with eye-position standardised; (ii) face images morphed to a standard template to remove shape information; (iii) the shape information from faces only. Analyses based upon PCA of shape-free faces gave high predictions of FPs, while shape information itself contributed only to hits. Furthermore, while FPs were generally predictable from components early in the PCA, hits appear to be accounted for by later components. We conclude that shape and "texture" (the image-based information remaining after morphing) may be used separately by the human face processing system, and that PCA of images offers a useful tool for understanding this system

Top-Level Categories of Constitutively Organized Material Entities - Suggestions for a Formal Top-Level Ontology

Application oriented ontologies are important for reliably communicating and managing data in databases. Unfortunately, they often differ in the definitions they use and thus do not live up to their potential. This problem can be reduced when using a standardized and ontologically consistent template for the top-level categories from a top-level formal foundational ontology. This would support ontological consistency within application oriented ontologies and compatibility between them. The Basic Formal Ontology (BFO) is such a foundational ontology for the biomedical domain that has been developed following the single inheritance policy. It provides the top-level template within the Open Biological and Biomedical Ontologies Foundry. If it wants to live up to its expected role, its three top-level categories of material entity (i.e., 'object', 'fiat object part', 'object aggregate') must be exhaustive, i.e. every concrete material entity must instantiate exactly one of them.By systematically evaluating all possible basic configurations of material building blocks we show that BFO's top-level categories of material entity are not exhaustive. We provide examples from biology and everyday life that demonstrate the necessity for two additional categories: 'fiat object part aggregate' and 'object with fiat object part aggregate'. By distinguishing topological coherence, topological adherence, and metric proximity we furthermore provide a differentiation of clusters and groups as two distinct subcategories for each of the three categories of material entity aggregates, resulting in six additional subcategories of material entity.We suggest extending BFO to incorporate two additional categories of material entity as well as two subcategories for each of the three categories of material entity aggregates. With these additions, BFO would exhaustively cover all top-level types of material entity that application oriented ontologies may use as templates. Our result, however, depends on the premise that all material entities are organized according to a constitutive granularity

ROBINS-I: a tool for assessing risk of bias in non-randomized studies of interventions

Non-randomised studies of the effects of interventions are critical to many areas of healthcare evaluation, but their results may be biased. It is therefore important to understand and appraise their strengths and weaknesses. We developed ROBINS-I ("Risk Of Bias In Non-randomised Studies-of Interventions"), a new tool for evaluating risk of bias in estimates of the comparative effectiveness (harm or benefit) of interventions from studies that did not use randomisation to allocate units (individuals or clusters of individuals) to comparison groups. The tool will be particularly useful to those undertaking systematic reviews that include non-randomised studies

WIDER Advisory Group on International Economic Issues

(A research and training centre of the United Nations University

Methane Clumped Isotopes: Progress and Potential for a New Isotopic Tracer

The isotopic composition of methane is of longstanding geochemical interest, with important implications for understanding petroleum systems, atmospheric greenhouse gas concentrations, the global carbon cycle, and life in extreme environments. Recent analytical developments focusing on multiply substituted isotopologues (‘clumped isotopes’) are opening a valuable new window into methane geochemistry. When methane forms in internal isotopic equilibrium, clumped isotopes can provide a direct record of formation temperature, making this property particularly valuable for identifying different methane origins. However, it has also become clear that in certain settings methane clumped isotope measurements record kinetic rather than equilibrium isotope effects. Here we present a substantially expanded dataset of methane clumped isotope analyses, and provide a synthesis of the current interpretive framework for this parameter. In general, clumped isotope measurements indicate plausible formation temperatures for abiotic, thermogenic, and microbial methane in many geological environments, which is encouraging for the further development of this measurement as a geothermometer, and as a tracer for the source of natural gas reservoirs and emissions. We also highlight, however, instances where clumped isotope derived temperatures are higher than expected, and discuss possible factors that could distort equilibrium formation temperature signals. In microbial methane from freshwater ecosystems, in particular, clumped isotope values appear to be controlled by kinetic effects, and may ultimately be useful to study methanogen metabolism