3,368 research outputs found

    A Bayesian space–time model for clustering areal units based on their disease trends

    Get PDF
    Population-level disease risk across a set of non-overlapping areal units varies in space and time, and a large research literature has developed methodology for identifying clusters of areal units exhibiting elevated risks. However, almost no research has extended the clustering paradigm to identify groups of areal units exhibiting similar temporal disease trends. We present a novel Bayesian hierarchical mixture model for achieving this goal, with inference based on a Metropolis-coupled Markov chain Monte Carlo ((MC) 3 ) algorithm. The effectiveness of the (MC) 3 algorithm compared to a standard Markov chain Monte Carlo implementation is demonstrated in a simulation study, and the methodology is motivated by two important case studies in the United Kingdom. The first concerns the impact on measles susceptibility of the discredited paper linking the measles, mumps, and rubella vaccination to an increased risk of Autism and investigates whether all areas in the Scotland were equally affected. The second concerns respiratory hospitalizations and investigates over a 10 year period which parts of Glasgow have shown increased, decreased, and no change in risk

    Further elucidating the steroid isomerisation reaction mechanism of GSTA3-3

    Get PDF
    A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg, 2017.Glutathione S-transferase A3-3 is the most catalytically efficient steroid isomerase enzyme known in humans, transforming Δ5-androstene-3-17-dione into Δ4-androstene-3-17-dione. Though its mechanism of action remains unsolved. GSTA3-3 catalyses this reaction with at least ten-fold greater efficiency than GSTA1-1, its closest competitor in the Alpha class of GSTs. In order to examine the differences between Alpha class GSTs and to better elucidate the mechanism of GSTA3-3 the roles of Tyr9 and Arg15 were examined. Tyr9 is the major catalytic residue of Alpha class GSTs and Arg15 is proposed to be catalytically important to GSTA3-3 but never before experimentally examined. While the structure and stability of the Alpha class enzymes are highly comparable, subtle differences at the G-site of the enzymes account for GSTA3-3 having a ten-fold greater affinity for the substrate GSH. Y9F and R15L mutations, singly or together, have no effect on the structure and stability of GSTA3-3 (the same effect they have on GSTA1-1) despite the R15L mutation removing an interdomain salt-bridge at the active site. Hydrogen-deuterium exchange mass spectrometry also revealed that neither mutation had a significant effect on the conformational dynamics of GSTA3-3. The R15L and Y9F mutations are equally important to the specific activity of the steroid isomerase reaction; however, Arg15 is more important for lowering the pKa of GSH. Lowering the pKa of GSH being how GSTs catalyse their reactions. This suggests an additional role for Tyr9, with an important mechanistic implication. Factoring in the inability to detect an intermediate during the reaction, all data are in agreement with the mechanism being concerted and that Tyr9 acts as a proton shuttle. Additionally, there is evidence to suggest that Arg15 is integral to allowing GSTA3-3 to differentiate between Δ5-androstene-3-17-dione and Δ4-androstene-3-17-dione, indicating that Arg15 is a more important active-site residue than previously recognized.LG201

    Violencia doméstica y venta de cosa ajena

    Get PDF
    Traballo fin de grao (UDC.DER). Grao en Dereito. Curso 2015/201

    The Mandelstam-Leibbrandt Prescription in Light Cone Quantization Gauge Theories

    Get PDF
    Quantization of gauge theories on characteristic surfaces and in the light-cone gauge is discussed. Implementation of the Mandelstam-Leibbrandt prescription for the spurious singularity is shown to require two distinct null planes, with independent degrees of freedom initialized on each. The relation of this theory to the usual light-cone formulation of gauge field theory, using a single null plane, is described. A connection is established between this formalism and a recently given operator solution to the Schwinger model in the light-cone gauge

    Observation simulation experiments with regional prediction models

    Get PDF
    Research efforts in FY 1990 included studies employing regional scale numerical models as aids in evaluating potential contributions of specific satellite observing systems (current and future) to numerical prediction. One study involves Observing System Simulation Experiments (OSSEs) which mimic operational initialization/forecast cycles but incorporate simulated Advanced Microwave Sounding Unit (AMSU) radiances as input data. The objective of this and related studies is to anticipate the potential value of data from these satellite systems, and develop applications of remotely sensed data for the benefit of short range forecasts. Techniques are also being used that rely on numerical model-based synthetic satellite radiances to interpret the information content of various types of remotely sensed image and sounding products. With this approach, evolution of simulated channel radiance image features can be directly interpreted in terms of the atmospheric dynamical processes depicted by a model. Progress is being made in a study using the internal consistency of a regional prediction model to simplify the assessment of forced diabatic heating and moisture initialization in reducing model spinup times. Techniques for model initialization are being examined, with focus on implications for potential applications of remote microwave observations, including AMSU and Special Sensor Microwave Imager (SSM/I), in shortening model spinup time for regional prediction

    PCBs : exposures, effects, remediation, and regulation with special emphasis on PCBs in schools

    Get PDF
    Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Environmental Science and Pollution Research 23 (2016): 1971-1974, doi:10.1007/s11356-015-5774-y.The Eighth International PCB Workshop: PCBs in Schools was held in Woods Hole, MA, October 5-9, 2014, and was attended by more than 130 scientists and other interested persons, including citizen’s groups and concerned parents. The program included a wide range of thematic areas. Presentations addressed essential questions and progress toward understanding mechanisms of PCB toxication and risks of PCB exposure. Presentations were also held illuminating several key PCB contamination problems.2016-12-0

    Celebrating and sustaining Indigenous knowledges through research

    Get PDF
    This paper reports on the growth of research within the World Indigenous Nations Higher Education Consortium (WINHEC). The focus is the research and later, research and journal working group. The intent is to discuss the publication of the WINHEC Journal, discussion papers and other activities such as the development of the Research Standards while analysing the underpinning imperatives to such work. The paper will also examine the complexity of progressing research, founded in local knowledge, aligned internationally to broader conceptions of Indigenous knowledge. The suggestion underlying this paper is that if research is undertaken from a position of Indigenous knowledge and epistemology, it will celebrate and sustain Indigenous people
    • …
    corecore