26 research outputs found

    Determination of nutrient salts by automatic methods both in seawater and brackish water: the phosphate blank

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    9 páginas, 2 tablas, 2 figurasThe main inconvenience in determining nutrients in seawater by automatic methods is simply solved: the preparation of a suitable blank which corrects the effect of the refractive index change on the recorded signal. Two procedures are proposed, one physical (a simple equation to estimate the effect) and the other chemical (removal of the dissolved phosphorus with ferric hydroxide).Support for this work came from CICYT (MAR88-0245 project) and Conselleria de Pesca de la Xunta de GaliciaPeer reviewe

    The Alberta Congenital Anomalies Surveillance System: a 40-year review with prevalence and trends for selected congenital anomalies, 1997–2019

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    IntroductionCurrent published long-term provincial or territorial congenital anomaly data are lacking for Canada. We report on prevalence (per 1000 total births) and trends in 1997–2019, in Alberta, Canada, for selected congenital anomalies. Associated risk factors are also discussed. MethodsWe used data from the Alberta Congenital Anomalies Surveillance System (ACASS) to calculate the prevalence and perform chi-square linear trend analyses. ResultsFrom 1997 to 2019, the overall prevalence of neural tube defects was stable, at 0.74 per 1000 total births. The same was true for spina bifida (0.38), orofacial clefts (1.99), more severe CHDs (transposition of the great arteries, 0.38; tetralogy of Fallot, 0.33; and hypoplastic left heart syndrome, 0.32); and gastroschisis (0.38). Anencephaly, cleft palate and anorectal malformation significantly decreased with a prevalence of 0.23, 0.75 and 0.54 per 1000 total births, respectively. Significantly increasing trends were reported for anotia/microtia (0.24), limb reduction anomalies (0.73), omphalocele (0.36) and Down syndrome (2.21) and for hypospadias and undescended testes (4.68 and 5.29, respectively, per 1000 male births). ConclusionCongenital anomalies are an important public health concern with significant social and societal costs. Surveillance data gathered by ACASS for over 40 years can be used for planning and policy decisions and the evaluation of prevention strategies. Contributing genetic and environmental factors are discussed as is the need for continued surveillance and research

    Le système de surveillance des anomalies congénitales de l’Alberta : compte rendu des données sur 40 ans avec prévalence et tendances de certaines anomalies congénitales entre 1997 et 2019

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    IntroductionOn manque de données provinciales ou territoriales à long terme publiées et actuelles sur les anomalies congénitales Au Canada. Cette étude fait état de la prévalence (pour 1000 naissances totales) et des tendances pour diverses anomalies congénitales de 1997 à 2019 en Alberta (Canada). Les facteurs de risque associés sont également abordés. MethodsNous avons utilisé les données du Système de surveillance des anomalies congénitales de l’Alberta (ACASS) pour calculer la prévalence et effectuer des analyses de tendance linéaire par test du chi carré. ResultsEntre 1997 et 2019, la prévalence globale des anomalies du tube neural est demeurée stable, à 0,74 pour 1000 naissances totales. C’était également le cas pour le spina bifida (0,38), les fentes orofaciales (1,99), les cardiopathies congénitales graves (transposition des grandes artères, 0,38; tétralogie de Fallot, 0,33; hypoplasie du coeur gauche, 0,32) et le gastroschisis (0,38). L’anencéphalie, la fente palatine et les anomalies anorectales ont diminué significativement, avec une prévalence de respectivement 0,23, 0,75 et 0,54 pour 1000 naissances totales. Une tendance significativement à la hausse a été relevée pour l’anotie/microtie (0,24), les anomalies de raccourcissement des membres (0,73), l’omphalocèle (0,36) et le syndrome de Down (2,21), ainsi que pour l’hypospadias et la cryptorchidie (respectivement 4,68 et 5,29 pour 1 000 naissances masculines). ConclusionLes anomalies congénitales constituent un important problème de santé publique, qui est associé à des coûts sociaux et sociétaux substantiels. Les données de surveillance recueillies par l’ACASS sur plus de 40 ans peuvent servir à la planification et aux décisions en matière de politiques ainsi qu’à l’évaluation des stratégies de prévention. Les facteurs génétiques et environnementaux contributifs sont abordés, de même que la nécessité de poursuivre la surveillance et la recherche

    Replication of the association between CHRNA4 rs1044396 and harm avoidance in a large population-based sample

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    Harm avoidance is a personality trait characterized by excessive worrying and fear of uncertainty, which has repeatedly been related to anxiety disorders. Converging lines of research in rodents and humans point towards an involvement of the nicotinic cholinergic system in the modulation of anxiety. Most notably, the rs1044396 polymorphism in the CHRNA4 gene, which codes for the alpha 4 subunit of the nicotinic acetylcholine receptor, has been linked to negative emotionality traits including harm avoidance in a recent study. Against this background, we investigated the association between harm avoidance and the rs1044396 polymorphism using data from N=1673 healthy subjects, which were collected in the context of the German multi-centre study 'Genetics of Nicotine Dependence and Neurobiological Phenotypes'. Homozygous carriers of the C-allele showed significantly higher levels of harm avoidance than homozygous T-allele carriers, with heterozygous subjects exhibiting intermediate scores. The effect was neither modulated by age or gender nor by smoking status. By replicating previous findings in a large population-based sample for the first time, the present study adds to the growing evidence suggesting an involvement of nicotinic cholinergic mechanism in anxiety and negative emotionality, which may pose an effective target for medical treatment. (C) 2015 Elsevier B.V. and ECNP. All rights reserved

    The German multi-centre study on smoking-related behavior-description of a population-based case-control study

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    Tobacco smoking is a major risk factor for most of the diseases leading in mortality. Nicotine dependence (ND), which sustains regular smoking, is now acknowledged to be under substantial genetic control with some environmental contribution. At present, however, genetic studies on ND are mostly conducted in populations that have been poorly characterized with regard to ND-related phenotypes for the simple reason that the respective populations were not primarily collected to study ND. The Germanmulti-centre study 'Genetics of Nicotine Dependence and Neurobiological Phenotypes', which is funded by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) as part of the Priority Program (Schwerpunktprogramm) SPP1226: 'Nicotine-Molecular and Physiological Effects in CNS', was intended to overcome some of these inherent problems of current genetic studies of ND. The multi-centre study is a population-based case-control study of smokers and never-smokers (n = 2396). The study was unique worldwide because it was the first large-scale genetic study specifically addressing ND with the collection of a wide range of environmental, psychosocial and neurobiological phenotypes. Study design and major population characteristics with emphasis on risk prediction of smoking status were presented in this paper

    Unobserved heterogeneity in hazard rate models: a test and an illustration from a study of career mobility

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    This paper proposes a test for neglected heterogeneity in continuous-time hazard rate models that can be done easily using generally available program packages. It is a score test appropriate for cases in which the variance of the heterogeneity is small and it can be applied quite generally, provided that the generalized residuals can be calculated. The test is demonstrated using data on the career trajectories of German males from the German Life History Study
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