5,475 research outputs found

    A Two-Stage Cluster Sampling Method Using Gridded Population Data, A GIS, And Google Earthtm Imagery in a Population-Based Mortality Survey in Iraq

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    Background Mortality estimates can measure and monitor the impacts of conflict on a population, guide humanitarian efforts, and help to better understand the public health impacts of conflict. Vital statistics registration and surveillance systems are rarely functional in conflict settings, posing a challenge of estimating mortality using retrospective population-based surveys. Results We present a two-stage cluster sampling method for application in population-based mortality surveys. The sampling method utilizes gridded population data and a geographic information system (GIS) to select clusters in the first sampling stage and Google Earth TM imagery and sampling grids to select households in the second sampling stage. The sampling method is implemented in a household mortality study in Iraq in 2011. Factors affecting feasibility and methodological quality are described. Conclusion Sampling is a challenge in retrospective population-based mortality studies and alternatives that improve on the conventional approaches are needed. The sampling strategy presented here was designed to generate a representative sample of the Iraqi population while reducing the potential for bias and considering the context specific challenges of the study setting. This sampling strategy, or variations on it, are adaptable and should be considered and tested in other conflict settings

    A Two-Stage Cluster Sampling Method Using Gridded Population Data, a GIS, and Google Earth(TM) Imagery in a Population-Based Mortality Survey in Iraq

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    BACKGROUND: Mortality estimates can measure and monitor the impacts of conflict on a population, guide humanitarian efforts, and help to better understand the public health impacts of conflict. Vital statistics registration and surveillance systems are rarely functional in conflict settings, posing a challenge of estimating mortality using retrospective population-based surveys. RESULTS: We present a two-stage cluster sampling method for application in population-based mortality surveys. The sampling method utilizes gridded population data and a geographic information system (GIS) to select clusters in the first sampling stage and Google Earth TM imagery and sampling grids to select households in the second sampling stage. The sampling method is implemented in a household mortality study in Iraq in 2011. Factors affecting feasibility and methodological quality are described. CONCLUSION: Sampling is a challenge in retrospective population-based mortality studies and alternatives that improve on the conventional approaches are needed. The sampling strategy presented here was designed to generate a representative sample of the Iraqi population while reducing the potential for bias and considering the context specific challenges of the study setting. This sampling strategy, or variations on it, are adaptable and should be considered and tested in other conflict settings

    ππ\pi\pi scattering S wave from the data on the reaction πpπ0π0n\pi^-p\to\pi^0\pi^0n

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    The results of the recent experiments on the reaction πpπ0π0n\pi^-p\to\pi^0\pi^0n performed at KEK, BNL, IHEP, and CERN are analyzed in detail. For the I=0 ππ\pi\pi S wave phase shift δ00\delta^0_0 and inelasticity η00\eta^0_0 a new set of data is obtained. Difficulties emerging when using the physical solutions for the π0π0\pi^0\pi^0 S and D wave amplitudes extracted with the partial wave analyses are discussed. Attention is drawn to the fact that, for the π0π0\pi^0\pi^0 invariant mass, m, above 1 GeV, the other solutions, in principle, are found to be more preferred. For clarifying the situation and further studying the f0(980)f_0(980) resonance thorough experimental investigations of the reaction πpπ0π0n\pi^-p\to\pi^0\pi^0n in the m region near the KKˉK\bar K threshold are required.Comment: 17 pages, 5 figure

    The migration of physicians from sub-Saharan Africa to the United States of America: measures of the African brain drain

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    BACKGROUND: The objective of this paper is to describe the numbers, characteristics, and trends in the migration to the United States of physicians trained in sub-Saharan Africa. METHODS: We used the American Medical Association 2002 Masterfile to identify and describe physicians who received their medical training in sub-Saharan Africa and are currently practicing in the USA. RESULTS: More than 23% of America's 771 491 physicians received their medical training outside the USA, the majority (64%) in low-income or lower middle-income countries. A total of 5334 physicians from sub-Saharan Africa are in that group, a number that represents more than 6% of the physicians practicing in sub-Saharan Africa now. Nearly 86% of these Africans practicing in the USA originate from only three countries: Nigeria, South Africa and Ghana. Furthermore, 79% were trained at only 10 medical schools. CONCLUSIONS: Physician migration from poor countries to rich ones contributes to worldwide health workforce imbalances that may be detrimental to the health systems of source countries. The migration of over 5000 doctors from sub-Saharan Africa to the USA has had a significantly negative effect on the doctor-to-population ratio of Africa. The finding that the bulk of migration occurs from only a few countries and medical schools suggests policy interventions in only a few locations could be effective in stemming the brain drain

    Average fraction of jet momentum carried by high P ⊥ leading hadrons

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    The average fraction, , of jet momentum carried by the associated charged leading hadron has been determined in the reaction p + N → h 1 + h 2 + X where N is the target nucleon; h 1 , h 2 are the leading particles of two jets produced at high P ⊥ . An 800 GeV/c proton beam and 4 nuclear targets: Be, Al, Fe and W were used. The distributions agree with the QCD-parton model predictions for single independent protonnucleon scattering and independent fragmentation process.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47888/1/10052_2005_Article_BF01483569.pd

    Search for bottom squarks in pbarp collisions at sqrt(s)=1.8 TeV

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    We report on a search for bottom squarks produced in pbarp collisions at sqrt(s) = 1.8 TeV using the D0 detector at Fermilab. Bottom squarks are assumed to be produced in pairs and to decay to the lightest supersymmetric particle (LSP) and a b quark with branching fraction of 100%. The LSP is assumed to be the lightest neutralino and stable. We set limits on the production cross section as a function of bottom squark mass and LSP mass.Comment: 5 pages, Latex. submitted 3-12-1999 to PRD - Rapid Communicatio

    Les bulles « robustes »:Pourquoi il faut construire des logements en région parisienne

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    « Bulle » ou « pas bulle » ? La question taraude les observateurs et les acteurs du marché immobilier français. Nous examinons dans cet article les éléments empiriques et théoriques qui expliquent la hausse des prix récente et sa résistance aux retournements conjoncturels. En combinant la notion de bulle économique, les arguments de l’économie spatiale et une analyse d’économie politique, nous suggérons que la valorisation importante de l’immobilier en France est le résultat d’une logique rationnelle et conforte les intérêts des acteurs locaux. Dès lors, la forte valorisation peut être considérée comme une « bulle robuste », à même de résister à des chocs importants. Cette bulle organise un transfert intergénérationnel et peut avoir des effets positifs. Elle peut également renforcer la ségrégation spatiale, alimenter les inégalités territoriales et empêcher d’exploiter les économies d’agglomération possibles. L’analyse est détaillée sur la région Ile-de-France où ces phénomènes sont particulièrement marqués

    Conformation-dependent GAD65 autoantibodies in diabetes

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    Aims/hypothesis. Conformation-dependent autoantibodies directed against GAD65 are markers of Type 1 diabetes. In this study we aimed to determine whether the substitution of GAD65 with GAD67 amino acids would affect the binding of conformation-dependent GAD65 autoantibodies. Methods. We used PCR-based site-directed mutagenesis to generate a series of mutated GAD65 cDNA constructs in which specific GAD65 coding sequences for regions of the protein critical for autoantibody binding were replaced with GAD67 coding sequences. Results. The introduction of a point mutation at position 517, substituting glutamic acid with proline, markedly reduced the binding of disease-associated GAD65 antibodies. The binding of GAD65 antibodies to the E517P mutant was reduced in the sera of all newly diagnosed Type 1 diabetes patients (n=85) by a mean of 72% (p<0.0001) compared with binding to wild-type GAD65. Patients with latent autoimmune diabetes in adults (n=24) showed a similar reduction in binding (79% reduction, p<0.0001). First-degree relatives who subsequently progressed to Type 1 diabetes (n=12) showed a reduction in binding of 80% compared with a reduction of only 65% among relatives who had not progressed to disease (n=38; p=0.025). In healthy GAD65Ab-positive individuals who did not progress to diabetes during a 9-year follow-up period (n=51), binding to GAD65-E517P was reduced by only 28% compared with binding to wild-type GAD65. Conclusions/interpretation. Differences in autoantibody binding to wild-type GAD65 versus GAD65-E517P may provide predictive information about Type 1 diabetes risk beyond that provided by the presence or absence of GAD65 autoantibodies. Lack of binding to mutant GAD65-E517P defines GAD65-positive individuals who are at higher risk of developing diabetes
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