2,244 research outputs found

    Rapid assessment of the performance of malaria control strategies implemented by countries in the Amazon subregion using adequacy criteria: case study

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    <p>Abstract</p> <p>Background</p> <p>The objective of this study was to implement a rapid assessment of the performance of four malaria control strategies (indoor spraying, insecticide-treated bed nets, timely diagnosis, and artemisinin-based combination therapy) using adequacy criteria. The assessment was carried out in five countries of the Amazon subregion (Bolivia, Colombia, Ecuador, Guyana, and Peru).</p> <p>Methods</p> <p>A list of criteria in three areas was created for each of the four strategies: preliminary research that supports the design and adaptation of the control strategies, coverage of the control strategies and quality of the implementation of the strategies. The criteria were selected by the research team and based on the technical guidelines established by the World Health Organization. Each criterion included in the four lists was graded relative to whether evidence exists that the criterion is satisfied (value 1), not satisfied (value 0) or partially satisfied (value 0.5). The values obtained were added and reported according to a scale of three implementation categories: adequate, intermediate and deficient.</p> <p>Results</p> <p>Implementation of residual indoor spraying and timely diagnosis was adequate in one country and intermediate or deficient in the rest. Insecticide-treated bed nets ranged between deficient and intermediate in all the countries, while implementation of artemisinin-based combination therapy (ACT) was adequate in three countries and intermediate in the other two countries evaluated.</p> <p>Conclusions</p> <p>Although ACT is the strategy with the better implementation in all countries, major gaps exist in implementation of the other three malaria control strategies in terms of technical criteria, coverage and quality desiredThe countries must implement action plans to close the gaps in the various criteria and thereby improve the performance of the interventions. The assessment tools developed, based on adequacy criteria, are considered useful for a rapid assessment by malaria control authorities in the different countries.</p

    The Canada-UK Deep Submillimetre Survey: The Survey of the 14-hour field

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    We have used SCUBA to survey an area of 50 square arcmin, detecting 19 sources down to a 3sigma sensitivity limit of 3.5 mJy at 850 microns. We have used Monte-Carlo simulations to assess the effect of source confusion and noise on the SCUBA fluxes and positions, finding that the fluxes of sources in the SCUBA surveys are significantly biased upwards and that the fraction of the 850 micron background that has been resolved by SCUBA has been overestimated. The radio/submillmetre flux ratios imply that the dust in these galaxies is being heated by young stars rather than AGN. We have used simple evolution models based on our parallel SCUBA survey of the local universe to address the major questions about the SCUBA sources: (1) what fraction of the star formation at high redshift is hidden by dust? (2) Does the submillimetre luminosity density reach a maximum at some redshift? (3) If the SCUBA sources are proto-ellipticals, when exactly did ellipticals form? However, we show that the observations are not yet good enough for definitive answers to these questions. There are, for example, acceptable models in which 10 times as much high-redshift star formation is hidden by dust as is seen at optical wavelengths, but also acceptable ones in which the amount of hidden star formation is less than that seen optically. There are acceptable models in which very little star formation occurred before a redshift of three (as might be expected in models of hierarchical galaxy formation), but also ones in which 30% of the stars have formed by this redshift. The key to answering these questions are measurements of the dust temperatures and redshifts of the SCUBA sources.Comment: 41 pages (latex), 17 postscript figures, to appear in the November issue of the Astronomical Journa

    The dark matter content of the blue compact dwarf NGC 2915

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    NGC 2915 is a nearby blue compact dwarf with the HI properties of a late-type spiral. Its large, rotating HI disk (extending out to R ~ 22 B-band scale lengths) and apparent lack of stars in the outer HI disk make it a useful candidate for dark matter studies. New HI synthesis observations of NGC 2915 have been obtained using the Australian Telescope Compact Array. These data are combined with high-quality 3.6 μ\mum imaging from the Spitzer Infrared Nearby Galaxies Survey. The central regions of the HI disk are shown to consist of two distinct HI concentrations with significantly non-Gaussian line profiles. We fit a tilted ring model to the HI velocity field to derive a rotation curve. This is used as input for mass models that determine the contributions from the stellar and gas disks as well as the dark matter halo. The galaxy is dark-matter-dominated at nearly all radii. At the last measured point of the rotation curve, the total mass to blue light ratio is ~ 140 times solar, making NGC 2915 one of the darkest galaxies known. We show that the stellar disk cannot account for the steeply-rising portion of the observed rotation curve. The best-fitting dark matter halo is a pseudo-isothermal sphere with a core density ρ00.17±0.03\rho_0\sim 0.17 \pm 0.03 \msun pc3^{-3} and a core radius rc0.9±0.1r_c\sim 0.9 \pm 0.1 kpc.Comment: MNRAS in press. 17 pages, 15 figure

    Exploración de opciones agroecológicas en el sistema de milpa de la Costa Chica, México

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    Los sistemas de producción de la Costa Chica enfrentan serios problemas de degradación del suelo y baja productividad de maíz y jamaica. Esta situación demanda el diseño e implementación de alternativas agroecológicas para revertir esta problemática. Diversos protocolos experimentales que incluyeron opciones de fertilización e integración de leguminosas se desarrollaron en milpas de agricultores. Con base en los resultados encontrados se realizaron exploraciones a través de modelaje para evaluar el impacto de esas alternativas en el rendimiento de maíz y en el balance de materia orgánica a nivel sistema de producción. Los resultados demostraron que la integración de los componentes evaluados (fertilización, leguminosas y retención de residuos) tuvo efectos positivos en los ingresos familiares y en el balance de materia orgánica.Farming systems in Costa Chica, Mexico face problems related to soil degradation and low crop productivity. This situation requires designing and implementing agroecological alternatives to improve cropping systems. Several experimental trials that included fertilization and intercropping of legumes in current milpa systems were carried out in farmers´ fields. Based on the results modeling explorations were carried out to evaluate the impacts of these field-level agroecological options at farm level. The results showed that the integration of the evaluated components (fertilization, legumes and crop residues retention) had positive effects on family income and organic matter balances.Eje A1 Sistemas de producción de base agroecológica (Trabajos científicos)Facultad de Ciencias Agrarias y Forestale

    Extragalactic Results from the Infrared Space Observatory

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    More than a decade ago the IRAS satellite opened the realm of external galaxies for studies in the 10 to 100 micron band and discovered emission from tens of thousands of normal and active galaxies. With the 1995-1998 mission of the Infrared Space Observatory the next major steps in extragalactic infrared astronomy became possible: detailed imaging, spectroscopy and spectro-photometry of many galaxies detected by IRAS, as well as deep surveys in the mid- and far- IR. The spectroscopic data reveal a wealth of detail about the nature of the energy source(s) and about the physical conditions in galaxies. ISO's surveys for the first time explore the infrared emission of distant, high-redshift galaxies. ISO's main theme in extragalactic astronomy is the role of star formation in the activity and evolution of galaxies.Comment: 106 pages, including 17 figures. Ann.Rev.Astron.Astrophys. (in press), a gzip'd pdf file (667kB) is also available at http://www.mpe.mpg.de/www_ir/preprint/annrev2000.pdf.g

    Branch-and-lift algorithm for deterministic global optimization in nonlinear optimal control

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    This paper presents a branch-and-lift algorithm for solving optimal control problems with smooth nonlinear dynamics and potentially nonconvex objective and constraint functionals to guaranteed global optimality. This algorithm features a direct sequential method and builds upon a generic, spatial branch-and-bound algorithm. A new operation, called lifting, is introduced, which refines the control parameterization via a Gram-Schmidt orthogonalization process, while simultaneously eliminating control subregions that are either infeasible or that provably cannot contain any global optima. Conditions are given under which the image of the control parameterization error in the state space contracts exponentially as the parameterization order is increased, thereby making the lifting operation efficient. A computational technique based on ellipsoidal calculus is also developed that satisfies these conditions. The practical applicability of branch-and-lift is illustrated in a numerical example. © 2013 Springer Science+Business Media New York

    Meta-DiSc: a software for meta-analysis of test accuracy data

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    BACKGROUND: Systematic reviews and meta-analyses of test accuracy studies are increasingly being recognised as central in guiding clinical practice. However, there is currently no dedicated and comprehensive software for meta-analysis of diagnostic data. In this article, we present Meta-DiSc, a Windows-based, user-friendly, freely available (for academic use) software that we have developed, piloted, and validated to perform diagnostic meta-analysis. RESULTS: Meta-DiSc a) allows exploration of heterogeneity, with a variety of statistics including chi-square, I-squared and Spearman correlation tests, b) implements meta-regression techniques to explore the relationships between study characteristics and accuracy estimates, c) performs statistical pooling of sensitivities, specificities, likelihood ratios and diagnostic odds ratios using fixed and random effects models, both overall and in subgroups and d) produces high quality figures, including forest plots and summary receiver operating characteristic curves that can be exported for use in manuscripts for publication. All computational algorithms have been validated through comparison with different statistical tools and published meta-analyses. Meta-DiSc has a Graphical User Interface with roll-down menus, dialog boxes, and online help facilities. CONCLUSION: Meta-DiSc is a comprehensive and dedicated test accuracy meta-analysis software. It has already been used and cited in several meta-analyses published in high-ranking journals. The software is publicly available at

    History of Galaxy Interactions and their Impact on Star Formation over the Last 7 Gyr from GEMS

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    We perform a comprehensive estimate of the frequency of galaxy mergers and their impact on star formation over z~0.24--0.80 (lookback time T_b~3--7 Gyr) using 3698 (M*>=1e9 Msun) galaxies with GEMS HST, COMBO-17, and Spitzer data. Our results are: (1) Among 790 high mass (M*>=2.5e10 Msun) galaxies, the visually-based merger fraction over z~0.24--0.80, ranges from 9%+-5% to 8%+-2%. Lower limits on the major and minor merger fractions over this interval range from 1.1% to 3.5%, and 3.6% to 7.5%, respectively. This is the first approximate empirical estimate of the frequency of minor mergers at z<1. For a visibility timescale of ~0.5 Gyr, it follows that over T_b~3--7 Gyr, ~68% of high mass systems have undergone a merger of mass ratio >1/10, with ~16%, 45%, and 7% of these corresponding respectively to major, minor, and ambiguous `major or minor' mergers. The mean merger rate is a few x 1e-4 Gyr-1 Mpc-3. (2) We compare the empirical merger fraction and rate for high mass galaxies to a suite of Lambda CDM-based models: halo occupation distribution models, semi-analytic models, and hydrodynamic SPH simulations. We find qualitative agreement between observations and models such that the (major+minor) merger fraction or rate from different models bracket the observations, and show a factor of five dispersion. Near-future improvements can now start to rule out certain merger scenarios. (3) Among ~3698 M*>=1e9 Msun galaxies, we find that the mean SFR of visibly merging systems is only modestly enhanced compared to non-interacting galaxies over z~0.24--0.80. Visibly merging systems only account for less than 30% of the cosmic SFR density over T_b~3--7 Gyr. This suggests that the behavior of the cosmic SFR density over the last 7 Gyr is predominantly shaped by non-interacting galaxies.Comment: Accepted for Publication in the Astrophysical Journal. 17 pages of text, 21 figures, 3 tables. Uses emulateapj5.st

    Coxiella burnetii Phagocytosis Is Regulated by GTPases of the Rho Family and the RhoA Effectors mDia1 and ROCK

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    The GTPases belonging to the Rho family control the actin cytoskeleton rearrangements needed for particle internalization during phagocytosis. ROCK and mDia1 are downstream effectors of RhoA, a GTPase involved in that process. Coxiella burnetii, the etiologic agent of Q fever, is internalized by the host´s cells in an actin-dependent manner. Nevertheless, the molecular mechanism involved in this process has been poorly characterized. This work analyzes the role of different GTPases of the Rho family and some downstream effectors in the internalization of C. burnetii by phagocytic and non-phagocytic cells. The internalization of C. burnetii into HeLa and RAW cells was significantly inhibited when the cells were treated with Clostridium difficile Toxin B which irreversibly inactivates members of the Rho family. In addition, the internalization was reduced in HeLa cells that overexpressed the dominant negative mutants of RhoA, Rac1 or Cdc42 or that were knocked down for the Rho GTPases. The pharmacological inhibition or the knocking down of ROCK diminished bacterium internalization. Moreover, C. burnetii was less efficiently internalized in HeLa cells overexpressing mDia1-N1, a dominant negative mutant of mDia1, while the overexpression of the constitutively active mutant mDia1-ΔN3 increased bacteria uptake. Interestingly, when HeLa and RAW cells were infected, RhoA, Rac1 and mDia1 were recruited to membrane cell fractions. Our results suggest that the GTPases of the Rho family play an important role in C. burnetii phagocytosis in both HeLa and RAW cells. Additionally, we present evidence that ROCK and mDia1, which are downstream effectors of RhoA, are involved in that processFil: Salinas Ojeda, Romina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Ortiz Flores, Rodolfo Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Distel, Jesús Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Aguilera, Milton Osmar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Colombo, Maria Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Beron, Walter. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; Argentin
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