850 research outputs found

    New Limits to the Infrared Background: Bounds on Radiative Neutrino Decay and on Contributions of Very Massive Objects to the Dark Matter Problem

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    From considering the effect of γ-γ interactions on recently observed TeV gamma-ray spectra, improved limits are set to the density of extragalactic infrared photons which are robust and essentially model independent. The resulting limits are more than an order of magnitude more restrictive than direct observations in the 0.025–0.3 eV regime. These limits are used to improve constraints on radiative neutrino decay in the mass range above 0.05 eV and to rule out very massive objects as providing the dark matter needed to explain galaxy rotation curves. Lower bounds on the maximum distance which TeV gamma rays may probe are also derived

    Cost-Effectiveness of Alternative Models of Community Health Workers for promotion of Maternal, Newborn and Child Health in Northern Nigeria

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    Background: Community health workers (CHWs) have proven to be successful in mobilizing rural populations to utilize primary health services where they can be supported by skilled health workers. This study assessed the cost-effectiveness of three CHW models implemented in northern Nigeria. Method: Using a quasi-experimental design, we compare the costs and health outcomes for communities where CHW models were implemented versus those where no CHW models were implemented. The three CHW models were Community Volunteer (CV), Nigeria Subsidy Reinvestment and Empowerment Programme for Maternal and Child Health Village Health Worker (VHW), and the Junior Community Health Extension Worker providing community based service delivery (JCHEW-CBSD). The unit costs, consultation patterns, benefit-cost ratios, and cost-effectiveness ratios were calculated for the three CHW models. Results: Compared to the CVs, the VHWs and the JCHEW-CBSDs had the highest levels of interactions in the community, each helping to educate 120-130 pregnant women each year. JCHEW-CBSDs made the most referrals for antenatal care (220) and facility births (122); however, women who interacted with the VHWs increased their antenatal care visits the most, with 92% of the women having made at least one and 70% having made 4+ ANC visits. The unit cost of the CVs was lowest, compared to the other two models, at 127versus127 versus 3176 for the VHW model and 4443fortheJCHEWCBSDmodel.TheoutcomesperunitcostratioswerehighestfortheVHWmodel.Forevery4443 for the JCHEWCBSD model. The outcomes per unit cost ratios were highest for the VHW model. For every 1000 invested in the VHW, there were 54 ANC 4+ visits and 95.9 deliveries attended by a skilled birth attendant. The Incremental Cost-Effectiveness Ratios for the VHW model were also lower than for the JCHEW-CBSD model, ranging from a low of an additional 25perincrementalANCvisitsto25 per incremental ANC visits to 152 for increments in attended deliveries, the latter amount three times lower than for the JCHEW-CBSD model. Conclusion: This cost-effectiveness study of CHW models in Northern Nigeria shows that the SURE-P VHW model was most cost-effective. The VHW model, an enhanced volunteer model, promises the greatest return on investment if scaled up in northern Nigeria and settings with similar health care delivery contexts

    Functional dynamic genetic effects on gene regulation are specific to particular cell types and environmental conditions

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    Genetic effects on gene expression and splicing can be modulated by cellular and environmental factors; yet interactions between genotypes, cell type and treatment have not been comprehensively studied together. We used an induced pluripotent stem cell system to study multiple cell types derived from the same individuals and exposed them to a large panel of treatments. Cellular responses involved different genes and pathways for gene expression and splicing, and were highly variable across contexts. For thousands of genes, we identified variable allelic expression across contexts and characterized different types of gene-environment interactions, many of which are associated with complex traits. Promoter functional and evolutionary features distinguished genes with elevated allelic imbalance mean and variance. On average half of the genes with dynamic regulatory interactions were missed by large eQTL mapping studies, indicating the importance of exploring multiple treatments to reveal previously unrecognized regulatory loci that may be important for disease

    Searching for gravitational waves from known pulsars

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    We present upper limits on the amplitude of gravitational waves from 28 isolated pulsars using data from the second science run of LIGO. The results are also expressed as a constraint on the pulsars' equatorial ellipticities. We discuss a new way of presenting such ellipticity upper limits that takes account of the uncertainties of the pulsar moment of inertia. We also extend our previous method to search for known pulsars in binary systems, of which there are about 80 in the sensitive frequency range of LIGO and GEO 600.Comment: Accepted by CQG for the proceeding of GWDAW9, 7 pages, 2 figure

    Framework, principles and recommendations for utilising participatory methodologies in the co-creation and evaluation of public health interventions

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    Background: Due to the chronic disease burden on society, there is a need for preventive public health interventions to stimulate society towards a healthier lifestyle. To deal with the complex variability between individual lifestyles and settings, collaborating with end-users to develop interventions tailored to their unique circumstances has been suggested as a potential way to improve effectiveness and adherence. Co-creation of public health interventions using participatory methodologies has shown promise but lacks a framework to make this process systematic. The aim of this paper was to identify and set key principles and recommendations for systematically applying participatory methodologies to co-create and evaluate public health interventions. Methods: These principles and recommendations were derived using an iterative reflection process, combining key learning from published literature in addition to critical reflection on three case studies conducted by research groups in three European institutions, all of whom have expertise in co-creating public health interventions using different participatory methodologies. Results: Key principles and recommendations for using participatory methodologies in public health intervention co-creation are presented for the stages of: Planning (framing the aim of the study and identifying the appropriate sampling strategy); Conducting (defining the procedure, in addition to manifesting ownership); Evaluating (the process and the effectiveness) and Reporting (providing guidelines to report the findings). Three scaling models are proposed to demonstrate how to scale locally developed interventions to a population level. Conclusions: These recommendations aim to facilitate public health intervention co-creation and evaluation utilising participatory methodologies by ensuring the process is systematic and reproducible

    Search for Gravitational Waves from Primordial Black Hole Binary Coalescences in the Galactic Halo

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    We use data from the second science run of the LIGO gravitational-wave detectors to search for the gravitational waves from primordial black hole (PBH) binary coalescence with component masses in the range 0.2--1.0M⊙1.0 M_\odot. The analysis requires a signal to be found in the data from both LIGO observatories, according to a set of coincidence criteria. No inspiral signals were found. Assuming a spherical halo with core radius 5 kpc extending to 50 kpc containing non-spinning black holes with masses in the range 0.2--1.0M⊙1.0 M_\odot, we place an observational upper limit on the rate of PBH coalescence of 63 per year per Milky Way halo (MWH) with 90% confidence.Comment: 7 pages, 4 figures, to be submitted to Phys. Rev.

    Constructing seasonally adjusted data with time-varying confidence intervals

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    Seasonal adjustment methods transform observed time series data into estimated data, where these estimated data are constructed such that they show no or almost no seasonal variation. An advantage of model-based methods is that these can provide confidence intervals around the seasonally adjusted data. One particularly useful time series model for seasonal adjustment is the basic structural time series [BSM] model. The usual premise of the BSM is that the variance of each of the components is constant. In this paper we address the possibility that the variance of the trend component in a macro-economic time series in some way depends on the business cycle. One reason for doing so is that one can expect that there is more uncertainty in recession periods. We extend the BSM by allowing for a business-cycle dependent variance in the level equation. Next we show how this affects the confidence intervals of seasonally adjusted data. We apply our extended BSM to monthly US unemployment and we show that the estimated confidence intervals for seasonally adjusted unemployment change with past changes in the oil price
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