418 research outputs found

    Implications of the Precautionary Principle for Environmental Regulation in the United States: Examples from the Control of Hazardous Air Pollutants in the 1990 Clean Air Act Amendments

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    Goldstein and Carruth argue that the hazardous air pollutant provisions of the 1990 Clean Air Act Amendments provide an example of the Precautionary Principle incorporated into US environmental legislation. Evaluating the outcome thus far leads them to the conclusion that utilizing the Precautionary Principle as a basis for legislation can be problematic to public-health goals

    An Environment Monitoring Package for the International Space Station

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    The first elements of the International Space Station (ISS) will soon be launched into space and over the next few years ISS will be assembled on orbit into its final configuration. Experiments will be performed on a continuous basis both inside and outside the station. External experiments will be mounted on attached payload locations specifically designed to accommodate experiments, provide data and supply power from ISS. From the beginning of the space station program it has been recognized that experiments will require knowledge of the external local environment which can affect the science being performed and may impact lifetime and operations of the experiment hardware. Recently an effort was initiated to design and develop an Environment Monitoring Package (EMP). This paper describes the derivation of the requirements for the EMP package, the type of measurements that the EMP will make and types of instruments which will be employed to make these measurements

    Semigroup Closures of Finite Rank Symmetric Inverse Semigroups

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    We introduce the notion of semigroup with a tight ideal series and investigate their closures in semitopological semigroups, particularly inverse semigroups with continuous inversion. As a corollary we show that the symmetric inverse semigroup of finite transformations Iλn\mathscr{I}_\lambda^n of the rank n\leqslant n is algebraically closed in the class of (semi)topological inverse semigroups with continuous inversion. We also derive related results about the nonexistence of (partial) compactifications of classes of semigroups that we consider.Comment: With the participation of the new coauthor - Jimmie Lawson - the manuscript has been substantially revised and expanded. Accordingly, we have also changed the manuscript titl

    The continuity of the inversion and the structure of maximal subgroups in countably compact topological semigroups

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    In this paper we search for conditions on a countably compact (pseudo-compact) topological semigroup under which: (i) each maximal subgroup H(e)H(e) in SS is a (closed) topological subgroup in SS; (ii) the Clifford part H(S)H(S)(i.e. the union of all maximal subgroups) of the semigroup SS is a closed subset in SS; (iii) the inversion inv ⁣:H(S)H(S)\operatorname{inv}\colon H(S)\to H(S) is continuous; and (iv) the projection π ⁣:H(S)E(S)\pi\colon H(S)\to E(S), π ⁣:xxx1\pi\colon x\longmapsto xx^{-1}, onto the subset of idempotents E(S)E(S) of SS, is continuous

    Titan's lakes chemical composition: sources of uncertainties and variability

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    Between 2004 and 2007 the instruments of the CASSINI spacecraft discovered hydrocarbon lakes in the polar regions of Titan. We have developed a lake-atmosphere equilibrium model allowing the determination of the chemical composition of these liquid areas. The model is based on uncertain thermodynamic data and precipitation rates of organic species predicted to be present in the lakes and seas that are subject to spatial and temporal variations. Here we explore and discuss the influence of these uncertainties and variations. The errors and uncertainties relevant to thermodynamic data are simulated via Monte-Carlo simulations. Global Circulation Models (GCM) are also employed in order to investigate the possibility of chemical asymmetry between the south and the north poles, due to differences in precipitation rates. We find that mole fractions of compounds in the liquid phase have a high sensitivity to thermodynamic data used as inputs, in particular molar volumes and enthalpies of vaporization. When we combine all considered uncertainties, the ranges of obtained mole fractions are rather large (up to ~8500%) but the distributions of values are narrow. The relative standard deviations remain between 10% and ~300% depending on the compound considered. Compared to other sources of uncertainties and variability, deviation caused by surface pressure variations are clearly negligible, remaining of the order of a few percent up to ~20%. Moreover no significant difference is found between the composition of lakes located in north and south poles. Because the theory of regular solutions employed here is sensitive to thermodynamic data and is not suitable for polar molecules such as HCN and CH3CN, our work strongly underlines the need for experimental simulations and the improvement of Titan's atmospheric models.Comment: Accepted in Planetary and Space Scienc

    Anthropologists Respond to The Lancet EAT Commission

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    The Lancet Commissions are widely known as aspirational pieces, providing the mechanisms for consortia and networks of researchers to organize, collate, interrogate and publish around a range of subjects. Although the Commissions are predominantly led by biomedical scientists and cognate public health professionals, many address social science questions and involve social science expertise. Medical anthropologist David Napier was lead author of the Lancet Commission on Culture and Health (2014), for example, and all commissions on global health (https://www.thelancet.com/global-health/commissions) address questions of social structure, everyday life, the social determinants of health, and global inequalities.The Nutrire CoLab: Diana Burnett; Megan A. Carney; Lauren Carruth; Sarah Chard; Maggie Dickinson: Diana Burnett, Megan A. Carney, Lauren Carruth, Sarah Chard, Maggie Dickinson, Alyshia Gálvez, Hanna Garth, Jessica Hardin, Adele Hite, Heather Howard, Lenore Manderson, Emily Mendenhall, Abril Saldaña-Tejeda, Dana Simmons, Natali Valdez, Emily Vasquez, Megan Warin, Emily Yates-Doer

    Rare single gene disorders:estimating baseline prevalence and outcomes worldwide

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    As child mortality rates overall are decreasing, non-communicable conditions, such as genetic disorders, constitute an increasing proportion of child mortality, morbidity and disability. To date, policy and public health programmes have focused on common genetic disorders. Rare single gene disorders are an important source of morbidity and premature mortality for affected families. When considered collectively, they account for an important public health burden, which is frequently under-recognised. To document the collective frequency and health burden of rare single gene disorders, it is necessary to aggregate them into large manageable groupings and take account of their family implications, effective interventions and service needs. Here, we present an approach to estimate the burden of these conditions up to 5 years of age in settings without empirical data. This approaches uses population-level demographic data, combined with assumptions based on empirical data from settings with data available, to provide population-level estimates which programmes and policy-makers when planning services can use
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