63 research outputs found

    Does Particulate Air Pollution Contribute to Infant Death? A Systematic Review

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    There is now substantial evidence that both short- and long-term increases in ambient air pollution are associated with increased mortality and morbidity in adults and children. Children’s health is particularly vulnerable to environmental pollution, and infant mortality is still a major contributor to childhood mortality. In this systematic review we summarize and evaluate the current level of epidemiologic evidence of an association between particulate air pollution and infant mortality. We identified relevant publications using database searches with a comprehensive list of search terms and other established search methods. We included articles in the review according to specified inclusion criteria. Fifteen studies met our inclusion criteria. Evidence of an association between particulate air pollution and infant mortality in general was inconsistent, being reported from locations with largely comparable pollution levels. There was some evidence that the strength of association with particulate matter differed by subgroups of infant mortality. It was more consistent for post-neonatal mortality due to respiratory causes and sudden infant death syndrome. Differential findings for various mortality subgroups within studies suggest a stronger association of particulate air pollution with some causes of infant death. Research is needed to confirm and clarify these links, using the most appropriate methodologies for exposure assessment and control of confounders

    Search for Exotic Strange Quark Matter in High Energy Nuclear Reactions

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    We report on a search for metastable positively and negatively charged states of strange quark matter in Au+Pb reactions at 11.6 A GeV/c in experiment E864. We have sampled approximately six billion 10% most central Au+Pb interactions and have observed no strangelet states (baryon number A < 100 droplets of strange quark matter). We thus set upper limits on the production of these exotic states at the level of 1-6 x 10^{-8} per central collision. These limits are the best and most model independent for this colliding system. We discuss the implications of our results on strangelet production mechanisms, and also on the stability question of strange quark matter.Comment: 21 pages, 9 figures, to be published in Nuclear Physics A (Carl Dover memorial edition

    Subacute Sclerosing Panencephalitis: Results of the Canadian Paediatric Surveillance Program and review of the literature

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    BACKGROUND: Subacute Sclerosing Panencephalitis (SSPE) is so rare in developed countries with measles immunization programs that national active surveillance is now needed to capture sufficient number of cases for meaningful analysis of data. Through the Canadian Paediatric Surveillance Program (CPSP), the SSPE study was able to document a national incidence and determine the epidemiology of affected Canadian children. METHODS: Between 1997 and 2000, the CPSP surveyed monthly 1978 to 2294 Canadian pediatricians and sub-specialists for SSPE cases. The response rate varied from 82–86% over those years. RESULTS: Altogether, four SSPE cases were reported to the CPSP: one case before, two during and one after the study period. The incidence of SSPE in Canadian children was 0.06/million children/year. Of the four cases, diagnosed between ages four and 17 years, three children had measles infection in infancy. All children showed a progressive course of dementia, loss of motor skills and epilepsy. Two children were treated with isoprinosine and intraventricular interferon but died in less than three years from disease onset. One child did not have any treatment and died after seven years of illness. One child received intraventricular ribavirin and remains alive, but markedly impaired, nine years following diagnosis. CONCLUSION: The CPSP has demonstrated that Canadian paediatricians and paediatric neurologists may encounter cases of SSPE. This report highlights the clinical course of affected Canadian children and provides a review of the disease and its management

    Search for Strange Quark Matter Produced in Relativistic Heavy Ion Collisions

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    We present the final results from Experiment 864 of a search for charged and neutral strange quark matter produced in interactions of 11.5 GeV/c per nucleon Au beams with Pt or Pb targets. Searches were made for strange quark matter with A>4. Approximately 30 billion 10% most central collisions were sampled and no strangelet states with A<100 were observed. We find 90% confidence level upper limits of approximately 10^{-8} per central collision for both charged and neutral strangelets. These limits are for strangelets with proper lifetimes greater than 50 ns. Also limits for H^{0}-d and pineut production are given. The above limits are compared with the predictions of various models. The yields of light nuclei from coalescence are measured and a penalty factor for the addition of one nucleon to the coalescing nucleus is determined. This is useful in gauging the significance of our upper limits and also in planning future searches for strange quark matter.Comment: 35 pages, 18 figures, submitted to Phys. Rev.

    Non-canonical amino acids bearing thiophene and bithiophene: synthesis by an Ugi multicomponent reaction and studies on ion recognition ability

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    Novel thienyl and bithienyl amino acids with different substituents were obtained by a multicomponent Ugi reaction between a heterocyclic aldehyde, an amine, an acid and an isocyanide. Due to the presence of the sulphur heterocycle at the side chain, these unnatural amino acids are highly emissive and bear extra electron donating atoms so they were tested for their ability to act as fluorescent probes and chemosensors in the recognition of biomedically relevant ions in acetonitrile and acetonitrile/water solutions. The results obtained from spectrophotometric/spectrofluorimetric titrations in the presence of organic and inorganic anions, and alkaline; alkaline-earth and transition metal cations indicated that the bithienyl amino acid bearing a methoxy group is a selective colorimetric chemosensor for Cu2+, while the other (bi)thienyl amino acids act as fluorimetric chemosensors with high sensitivity towards Fe3+ and Cu2+ in a metal-ligand complex with 1:2 stoichiometry. The photophysical and ion sensing properties of these amino acids confirm their potential as fluorescent probes suitable for incorporation into peptidic frameworks with chemosensory ability.Thanks are due to Fundação para a Ciência e Tecnologia (FCT-Portugal) and FEDER-COMPETE for financial support through Centro de Química [PEst-C/QUI/UI0686/2013 (F-COMP-01-0124-FEDER-037302)] and a PhD grant to C.I.C. Esteves (SFRH/BD/68360/2010). The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network and was purchased with funds from FCT and FEDER.info:eu-repo/semantics/publishedVersio

    Reconciling Different Views on Responsible Leadership: A Rationality-Based Approach

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    Business leaders are increasingly responsible for the societal and environmental impacts of their actions. Yet conceptual views on responsible leadership differ in their definitions and theoretical foundations. This study attempts to reconcile these diverse views and uncover the phenomenon from a business leader's point of view. Based on rational egoism theory, this article proposes a formal mathematical model of responsible leadership that considers different types of incentives for stakeholder engagement. The analyses reveal that monetary and instrumental incentives are neither sufficient nor necessary for business leaders to consider societal and environmental stakeholder needs. Non-monetary and non-instrumental incentives, such as leaders' values and authenticity, as well as their planning horizons, counterbalance pure monetary and instrumental orientations. The model in this article complements the growing body of research on responsible leadership by reconciling its various conceptual views and providing a foundation for future theory development and testing
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