18 research outputs found

    Erratum: Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017

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    Interpretation: By quantifying levels and trends in exposures to risk factors and the resulting disease burden, this assessment offers insight into where past policy and programme efforts might have been successful and highlights current priorities for public health action. Decreases in behavioural, environmental, and occupational risks have largely offset the effects of population growth and ageing, in relation to trends in absolute burden. Conversely, the combination of increasing metabolic risks and population ageing will probably continue to drive the increasing trends in non-communicable diseases at the global level, which presents both a public health challenge and opportunity. We see considerable spatiotemporal heterogeneity in levels of risk exposure and risk-attributable burden. Although levels of development underlie some of this heterogeneity, O/E ratios show risks for which countries are overperforming or underperforming relative to their level of development. As such, these ratios provide a benchmarking tool to help to focus local decision making. Our findings reinforce the importance of both risk exposure monitoring and epidemiological research to assess causal connections between risks and health outcomes, and they highlight the usefulness of the GBD study in synthesising data to draw comprehensive and robust conclusions that help to inform good policy and strategic health planning

    Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017.

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    BACKGROUND: The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 comparative risk assessment (CRA) is a comprehensive approach to risk factor quantification that offers a useful tool for synthesising evidence on risks and risk-outcome associations. With each annual GBD study, we update the GBD CRA to incorporate improved methods, new risks and risk-outcome pairs, and new data on risk exposure levels and risk-outcome associations. METHODS: We used the CRA framework developed for previous iterations of GBD to estimate levels and trends in exposure, attributable deaths, and attributable disability-adjusted life-years (DALYs), by age group, sex, year, and location for 84 behavioural, environmental and occupational, and metabolic risks or groups of risks from 1990 to 2017. This study included 476 risk-outcome pairs that met the GBD study criteria for convincing or probable evidence of causation. We extracted relative risk and exposure estimates from 46 749 randomised controlled trials, cohort studies, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. Using the counterfactual scenario of theoretical minimum risk exposure level (TMREL), we estimated the portion of deaths and DALYs that could be attributed to a given risk. We explored the relationship between development and risk exposure by modelling the relationship between the Socio-demographic Index (SDI) and risk-weighted exposure prevalence and estimated expected levels of exposure and risk-attributable burden by SDI. Finally, we explored temporal changes in risk-attributable DALYs by decomposing those changes into six main component drivers of change as follows: (1) population growth; (2) changes in population age structures; (3) changes in exposure to environmental and occupational risks; (4) changes in exposure to behavioural risks; (5) changes in exposure to metabolic risks; and (6) changes due to all other factors, approximated as the risk-deleted death and DALY rates, where the risk-deleted rate is the rate that would be observed had we reduced the exposure levels to the TMREL for all risk factors included in GBD 2017

    Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017

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    Stanaway JD, Afshin A, Gakidou E, et al. Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017. Lancet. 2018;392(10159):1923-1994.Background The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 comparative risk assessment (CRA) is a comprehensive approach to risk factor quantification that offers a useful tool for synthesising evidence on risks and risk outcome associations. With each annual GBD study, we update the GBD CRA to incorporate improved methods, new risks and risk outcome pairs, and new data on risk exposure levels and risk outcome associations. Methods We used the CRA framework developed for previous iterations of GBD to estimate levels and trends in exposure, attributable deaths, and attributable disability-adjusted life-years (DALYs), by age group, sex, year, and location for 84 behavioural, environmental and occupational, and metabolic risks or groups of risks from 1990 to 2017. This study included 476 risk outcome pairs that met the GBD study criteria for convincing or probable evidence of causation. We extracted relative risk and exposure estimates from 46 749 randomised controlled trials, cohort studies, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. Using the counterfactual scenario of theoretical minimum risk exposure level (TMREL), we estimated the portion of deaths and DALYs that could be attributed to a given risk. We explored the relationship between development and risk exposure by modelling the relationship between the Socio-demographic Index (SDI) and risk-weighted exposure prevalence and estimated expected levels of exposure and risk-attributable burden by SDI. Finally, we explored temporal changes in risk-attributable DALYs by decomposing those changes into six main component drivers of change as follows: (1) population growth; (2) changes in population age structures; (3) changes in exposure to environmental and occupational risks; (4) changes in exposure to behavioural risks; (5) changes in exposure to metabolic risks; and (6) changes due to all other factors, approximated as the risk-deleted death and DALY rates, where the risk-deleted rate is the rate that would be observed had we reduced the exposure levels to the TMREL for all risk factors included in GBD 2017. Findings In 2017,34.1 million (95% uncertainty interval [UI] 33.3-35.0) deaths and 121 billion (144-1.28) DALYs were attributable to GBD risk factors. Globally, 61.0% (59.6-62.4) of deaths and 48.3% (46.3-50.2) of DALYs were attributed to the GBD 2017 risk factors. When ranked by risk-attributable DALYs, high systolic blood pressure (SBP) was the leading risk factor, accounting for 10.4 million (9.39-11.5) deaths and 218 million (198-237) DALYs, followed by smoking (7.10 million [6.83-7.37] deaths and 182 million [173-193] DALYs), high fasting plasma glucose (6.53 million [5.23-8.23] deaths and 171 million [144-201] DALYs), high body-mass index (BMI; 4.72 million [2.99-6.70] deaths and 148 million [98.6-202] DALYs), and short gestation for birthweight (1.43 million [1.36-1.51] deaths and 139 million [131-147] DALYs). In total, risk-attributable DALYs declined by 4.9% (3.3-6.5) between 2007 and 2017. In the absence of demographic changes (ie, population growth and ageing), changes in risk exposure and risk-deleted DALYs would have led to a 23.5% decline in DALYs during that period. Conversely, in the absence of changes in risk exposure and risk-deleted DALYs, demographic changes would have led to an 18.6% increase in DALYs during that period. The ratios of observed risk exposure levels to exposure levels expected based on SDI (O/E ratios) increased globally for unsafe drinking water and household air pollution between 1990 and 2017. This result suggests that development is occurring more rapidly than are changes in the underlying risk structure in a population. Conversely, nearly universal declines in O/E ratios for smoking and alcohol use indicate that, for a given SDI, exposure to these risks is declining. In 2017, the leading Level 4 risk factor for age-standardised DALY rates was high SBP in four super-regions: central Europe, eastern Europe, and central Asia; north Africa and Middle East; south Asia; and southeast Asia, east Asia, and Oceania. The leading risk factor in the high-income super-region was smoking, in Latin America and Caribbean was high BMI, and in sub-Saharan Africa was unsafe sex. O/E ratios for unsafe sex in sub-Saharan Africa were notably high, and those for alcohol use in north Africa and the Middle East were notably low. Interpretation By quantifying levels and trends in exposures to risk factors and the resulting disease burden, this assessment offers insight into where past policy and programme efforts might have been successful and highlights current priorities for public health action. Decreases in behavioural, environmental, and occupational risks have largely offset the effects of population growth and ageing, in relation to trends in absolute burden. Conversely, the combination of increasing metabolic risks and population ageing will probably continue to drive the increasing trends in non-communicable diseases at the global level, which presents both a public health challenge and opportunity. We see considerable spatiotemporal heterogeneity in levels of risk exposure and risk-attributable burden. Although levels of development underlie some of this heterogeneity, O/E ratios show risks for which countries are overperforming or underperforming relative to their level of development. As such, these ratios provide a benchmarking tool to help to focus local decision making. Our findings reinforce the importance of both risk exposure monitoring and epidemiological research to assess causal connections between risks and health outcomes, and they highlight the usefulness of the GBD study in synthesising data to draw comprehensive and robust conclusions that help to inform good policy and strategic health planning. Copyright (C) 2018 The Author(s). Published by Elsevier Ltd

    Determinación de los coeficientes globales de transferencia de calor comparando los métodos DTML y ε-NUT

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    Thermal energy transfer processes are important problems to be solved within the engineering field. In this respect, the heat exchangers are one of the industry most-used equipment. Current research was carried out in an online system of hydrogen sulphide gas coolers, in order to determine the overall heat transfer coefficients by two methods, applying the passive experimentation procedure. Values calculated by means of the Logarithmic Mean Temperature Difference (LMTD) method vary between 11,1 and 73,3 W/(m²·K) , as compared to 11,0 and 58,9 W/(m²·K) when applying the Effectiveness-Number of Transfer Units (ε-NTU) method. Although similar results were obtained, it was recommended to use the LMTD approach for thermal evaluation of studied coolers system, which is used by most researchersLos procesos de transferencia de energía térmica son problemas importantes a resolver en el campo de la ingeniería. En este ámbito, los intercambiadores de calor son uno de los equipos más usados en la industria. La presente investigación se realizó en un sistema de enfriadores de sulfuro de hidrógeno en explotación, con el objetivo de determinar los coeficientes globales de transferencia de calor mediante dos métodos, aplicando el procedimiento de experimentación pasiva. Con el método de la Diferencia de Temperatura Media Logarítmica (DTML) se obtuvieron valores que oscilaron entre 11,1 y 73,3 W/(m²·K) , comparados con 11,0 y 58,9 W/(m²·K) al aplicar el método de la Efectividad-Número de Unidades de Transferencia (ε-NUT). Aunque los resultados obtenidos fueron similares, para la evaluación térmica del sistema de enfriadores estudiado se recomendó emplear la aproximación de la DTML, utilizada por la mayoría de los investigadore

    Red neuronal con entrenamiento dinámico para simulación de un sistema de intercambiadores de calor

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    RESUMEN Esta investigación propuso un modelo de red neuronal artificial con entrenamiento dinámico para predecir las temperaturas de salida de ambos fluidos en un sistema de intercambiadores de calor para monoetanolamina, realizando el entrenamiento, validación y pruebas con 31 680 juegos de datos obtenidos a través del método de experimentación pasiva. Con el perceptrón multicapa 4-3-2 se lograron correlaciones superiores al 98,76 %, y se corroboró que el entrenamiento dinámico proporciona respuestas más precisas que el entrenamiento único. Aplicando el primer enfoque se calcularon errores absolutos promedio de 0,419 y 0,372 K (para las variables temperatura de salida de la amina rica y de la amina pobre, respectivamente), comparados con 2,214 y 1,181 K para el segundo. Tales desviaciones no tienen una implicación significativa en el proceso tecnológico examinado, por lo que el modelo se considera apropiado para simular el desempeño de los intercambiadores de calor objeto de estudio.ABSTRACT This research proposed an artificial neural network model with dynamic training in order to predict both fluids outlet temperatures on a monoethanolamine heat exchangers system, doing the training, validation and testing with 31 680 data points gathered through the passive experimentation method. The 4-3-2 multilayer perceptron achieved correlations above 98.76 %, and it was corroborated that dynamic training strategy provided more accurate results than single training. Mean absolute errors of 0.419 and 0.372 K were obtained when applying the first approach (for rich amine and lean amine outlet temperatures as output variables, respectively), as compared to 2.214 and 1.181 K when implementing the second one. Since calculated deviations have no significant implication on the technological process under analysis, proposed model is considered appropriate for simulation of the studied heat exchangers performance

    Heat Exchange and Fouling Analysis on a Set of Hydrogen Sulphide Gas Coolers

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    The sulphide acid coolers are tube and shell jacketed heat exchangers designed to cool down the produced gas from 416,15 K to 310,15 K in addition to separate the sulphur carried over by the outlet gas from the reactor tower. The investigation was carried out by applying the passive experimentation process in an online cooler set in order to determine the heat transfer rates and fouling based on heat resistance. It was corroborated that the operation of this equipment outside design parameters increases outlet gas temperature and liquid sulphur carryovers. Efficiency loss is caused by fouling elements in the fluid, which results in changes in the overall heat transfer rate. The linear tendency of the fouling heat resistance based on time for three gas flowrates

    Effect of Tai Chi Practice on Stress, Self-Esteem, and Perceived Life Expectancy and a Structural Model of Relation Among These Variables Taking Into Account Age

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    The aims of this article were to (a) investigate whether practicing Tai Chi has an effect on stress, self-esteem, and perceived life expectancy and (b) contrast a structural model of relation between the three latter variables taking into account age. One scale to assess stress, another scale to assess perceived life expectancy, and the 10-item Rosenberg’s Self-Esteem Scale were administrated to a nonprobability sample of 86 Tai Chi practitioners and 91 sedentary persons. Tai Chi practitioners had a lower level of stress, a greater self-esteem, and a greater perceived life expectancy than sedentary persons. Self-esteem had an effect on stress and perceived life expectancy, and stress had an effect on perceived life expectancy in both Tai Chi practitioners and sedentary persons. Age was correlated to self-esteem among sedentary persons, but not among Tai Chi practitioners. Age had a direct effect on perceived life expectancy among Tai Chi practitioners, but not among sedentary persons. It is concluded that Tai Chi practice has a beneficial effect on stress, perceived life expectancy, and self-esteem

    Fibroblast Growth Factor Receptors (FGFRs) in Human Sperm: Expression, Functionality and Involvement in Motility Regulation.

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    Fibroblast growth factors receptors (FGFRs) have been widely characterized in somatic cells, but there is scarce evidence of their expression and function in mammalian gametes. The objective of the present study was to evaluate the expression of FGFRs in human male germ cells, to determine sperm FGFR activation by the FGF2 ligand and their participation in the regulation of sperm motility. The expression of FGFR1, 2, 3 and 4 mRNAs and proteins in human testis and localization of these receptors in germ cells of the seminiferous epithelium was demonstrated. In ejaculated sperm, FGFRs were localized to the acrosomal region and flagellum. Sperm exposure to FGF2 caused an increase in flagellar FGFR phosphorylation and activation of extracellular signal-regulated kinase (ERK) and protein kinase B (PKB or Akt) signaling pathways. Incubation with FGF2 led to a significant increase in the percentage of total and progressive sperm motility, as well as in sperm kinematics. All responses were prevented by sperm preincubation with BGJ398, a specific inhibitor of FGFR tyrosine kinase activity. In addition to confirming the expression of FGFRs in germ cells of the human testis, our study describes for the first time the presence, localization and functionality of human sperm FGFRs, and provides evidence of the beneficial effect of FGF2 upon sperm motility

    Localization of FGFRs in human seminiferous epithelium.

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    <p>Immunohistochemical analysis of FGFRs in human testis using anti FGFR antibodies; rabbit IgG was included as control. The specimens were counterstained with hematoxylin. S: Sertoli cell, Sg: spermatogonia, Sc: spermatocyte, St: spermatid. Arrows indicate immunoreactivity for FGFRs in the flagellum of elongating/elongated spermatids and the arrow head indicates FGFR4 immunoreactivity in spermatid acrosome. Bar: 20 μm.</p

    Activation of FGFR-related intracellular pathways in sperm exposed to FGF2.

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    <p>Sperm were incubated for a total 4-h period and exposed to FGF2 (0, 1, 10 and 100 ng/ml) for the last 15 min. In some aliquots, sperm were incubated for 15 min with BGJ398 (0.1 μM) before the addition of FGF2. (<b>A</b>) Immunolocalization of pERK and pAkt in sperm incubated in the absence of FGF2 (Control), with 100 ng/ml FGF2, and with BGJ398 + 100 ng/ml FGF2. Sperm were processed for immunocytochemistry, stained with anti pERK or pAkt and FITC-conjugated secondary antibodies; nuclei were stained with propidium iodide. Bar: 10 μm. (<b>B</b>) Percentage of sperm cells stained with anti pERK and anti pAkt after exposure to FGF2 in the absence (<b>left</b>) or presence of BGJ398 (<b>right</b>). Results are expressed as mean ± SEM, n = 4. * <i>P</i> < 0.05; ** <i>P</i> < 0.01 compared with Control. (<b>C</b>) Phosphorylation of ERK and Akt assessed by Western immunoblotting. Protein extracts from human sperm were subjected to SDS-PAGE and Western immunoblotting using anti pERK, ERK, pAkt and Akt antibodies. The estimated molecular weights of the protein bands are indicated on the right. (<b>D</b>) Densitometric analysis of Western immunoblotting results for pERK normalized to ERK and pAkt normalized to Akt. Results are expressed as mean ± SEM, n = 5 for ERK and n = 5 for Akt. * <i>P</i> < 0.05 and ** <i>P</i> < 0.01 compared with Control.</p
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