124 resultados para AK32-3392
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Marine organic matter (OM) sinks from surface waters to the seafloor via the biological pump. Benthic communities, which use this sedimented OM as energy and carbon source, produce dissolved organic matter (DOM) in the process of remineralization, enriching the sediment porewater with fresh DOM compounds. We hypothesized that in the oligotrophic deep Arctic basin the molecular signal of freshly deposited primary produced OM is restricted to the surface sediment pore waters which should differ from bottom water and deeper sediment pore water in DOM composition. This study focused on: 1) the molecular composition of the DOM in sediment pore waters of the deep Eurasian Arctic basins, 2) whether the signal of marine vs. terrigenous DOM is represented by different compounds preserved in the sediment pore waters and 3) whether there is any relation between Arctic Ocean ice cover and DOM composition. Molecular data, obtained via 15 Tesla Fourier transform ion cyclotron resonance mass spectrometer, were correlated with environmental parameters by partial least square analysis. The fresher marine detrital OM signal from surface waters was limited to pore waters from < 5 cm sediment depth. The productive ice margin stations showed higher abundances of peptides, unsaturated aliphatics and saturated fatty acids formulae, indicative of fresh OM/pigments deposition, compared to northernmost stations which had stronger aromatic signals. This study contributes to the understanding of the coupling between the Arctic Ocean productivity and its depositional regime, and how it will be altered in response to sea ice retreat and increasing river runoff.
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Biogeochemical reef studies carried out in 1981 and 1984 found low concentration of total natural and anthropogenic hydrocarbons in inshore waters. Detection of lignin in marine and bottom sediments indicates that the land has major effect on makeup of organic matter there. Comparison of compositions of organic matter in sea water, suspended matter and bottom sediments indicated that it was altered rapidly by the reef community. Thus, in the inshore zone of the island, runoff from the land is important in supplying nutrients to the reef ecosystem alongside with transport of nutrients by deep waters. Concentrations of nutri¬ents (N, P) in the inshore zone are higher than in waters of the tropical part of the ocean. Nitrogen is the limiting element in development of phytoplankton in the inshore zone.
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Geochemical changes in organic matter of bottom sediments from the Mozambique Basin at the river-sea barrier from the mouths of the Zambezi and Limpopo rivers toward the pelagic zone are discussed. Changes in bitumen, hydrolyzable material, humic acids, amino acids, n-alkanes, and polycyclic aromatic compounds resulting from genetic and diagenetic factors are described. This information is significant for paleoceanology reconstructions and for knowing ways of organic matter transformation into fossil forms.
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Background: Walking is integral to strategies to promote physical activity. We identified socio-demographic variations in walking for transport, and for recreation or exercise. Methods: Representative population data (n = 3392) from Australia were collected using computer assisted telephone interviewing, to examine adults’ participation in moderate- or brisk-paced walking for transport and walking for recreation or exercise; walking “sufficient” to meet the current public health guideline (> 150 min/wk); and, the contributions of total walking to meeting the guideline for total physical activity. Results: Rates of sufficient walking for transport (10% for men, 9% for women) were lower than those for walking for recreation or exercise (14% for both genders). Few socio-demographic differences emerged. Men over age 60 y were significantly less likely (OR = 0.40) to walk for transport; men age 45 to 59 y were more likely (OR = 1.56) to walk for recreation or exercise. Walking contributed more toward meeting the current public health guideline among women (15% to 21%) than among men (6% to 8%). Conclusions: There is potential for socially equitable increases in participation, through a focus on both walking for transport and on walking for recreation or exercise; attention to gender differences would be helpful.
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In this paper, we numerically investigate the impact of polarisation mode dispersion on the efficiency of compensation of nonlinear transmission penalties for systems employing one of more inline phase conjugation devices. We will show that reducing the spacing between phase conjugations allows for significantly improved performance in the presence polarisation mode dispersion or a significant relaxation in the acceptable level of polarization mode dispersion. We show that these results are consistent with previously presented full statistical analysis of nonlinear transmission appropriately adjusted for the reduced section length undergoing compensation.
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El clima es uno de los factores más e studiados a n ivel mundial y el más utilizado para la elaboración de planes de conservación de suelos y agua , construcción de obras hidráulicas que den un mejor uso y aprovechamiento de los recursos naturales. La construcción de C urvas de Intensidad – Duración – Frecuen cia como herramienta para la toma de decisión en el manejo, control y aprovechamiento del exceso de la precipitación es relevante para las zonas productivas y de escases de agua. El Objetivo de la investigación fue analizar el comportamiento de la s curvas IDF en la Cuenca N°68 con diferentes períodos de retorno de 5, 10, 15, 20 y 30 años con duraciones de 5, 10, 15, 30, 60 y 1 20 minutos. Se compararon dos modelos estadísticos Gumbel Tipo I y Aparicio 1997, ambos métodos permitieron es timar la intensidad de precipitación para los diferentes períodos de retorno. Para la selección de las estaciones pluviográficas se tomó como criterio las estaciones que proporcionaran la información necesaria para el periodo analizado 1975 - 1989 (Estación Aeropuerto Augusto C esa Sandino, Estación Tola, Estación Nandaime, Estación Masatepe Campos Azules). Al generar las curvas se presentaron algunos inconvenientes en la E stación Masatepe Campos A zules , esto fue ocasionado por posibles fallas en las estaciones pluviográficas como por ejemplo faltan de tinta en el pluviógrafo , cambio de operador, etc . El método de Gumbel Tipo I es el que nos brinda información más ajusta das a las condiciones del área de estudio ya que la prueba ajuste de bondad ajusto perfectamente los datos al mod elo estadístico mejorando los índices de probabilidad, en cambio el modelo estadístico Aparicio, 1997 sobre estima los valores de intensidad en los diferentes períodos de retornos, esto se observa al comparar los datos analizados con los datos calculados, los cuales presentan porcentaj es de sobrestimación del 7-54 %.
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Introdução – A frequência de dislipidemia em crianças e adolescentes tem vindo a aumentar rapidamente nos últimos anos, estando o seu aparecimento associado a fatores genéticos e ambientais. Este indicador, associado a outras doenças como a obesidade, constituem a síndrome metabólica e são considerados fatores de risco para doença cardiovascular e diabetes, que quando presentes na infância podem conduzir precocemente ao aparecimento destas doenças. Objetivos – Avaliar o perfil de indicadores de saúde de crianças no início de um Programa de Educação Contínua; Verificar os efeitos do Programa de Educação Contínua aplicado durante 36 meses (ginástica funcional, brincadeiras de rua e das aulas de natação), sobre os resultados dos exames iniciais de colesterol, triglicerídeos e do IMC. Métodos - Estudo quantitativo, exploratório e descritivo de corte transversal, realizado entre 2012 e 2015 numa amostra não probabilística por conveniência de 165 crianças, 70,0% da população-alvo. As crianças tinham entre 7 a 12 anos de idade, 40,59% entre 11 e 12 anos e 54% eram do sexo feminino. Eram beneficiárias de um plano de saúde que integrava um programa de intervenção (educação contínua e atividade física), designado Crescendo com Saúde e foram selecionadas através de critérios, como: dislipidemia (colesterol total e/ou triglicerídeos elevados), sobrepeso e/ou obesidade, e história familiar de HAS e DM. Os dados clínicos foram obtidos na consulta de enfermagem, utilizando-se a recolha de sangue para dosemanento do perfil lipídico no início do programa e a cada 6 meses e avaliação do IMC na fase inicial do programa e semanalmente. Para classificação do estado nutricional foram utilizados os pontos de corte da OMS (2007). Resultados – no início do programa 69% das crianças apresentavam hipercolesterolémia, 32% aumento do colesterol, 45% tinham excesso de peso (sobrepeso e obesidade) e 12% risco de sobrepeso. Após o programa de intervenção, das 53% crianças que participaram de forma regular, 29% apresentaram redução do colesterol, 16% dos triglicerídeos e o excesso de peso reduziu em 9%, aumentando contudo o risco de sobrepeso para 22%. Das que participaram de forma irregular, apenas 3% reduziram o perfil lipídico e 1% o estado nutricional. Conclusões – O programa de intervenção permitiu uma redução dos fatores de risco de doença metabólica e permitiu melhorar os hábitos das crianças estudadas e suas famílias. Estes resultados comprovam a eficácia a curto e médio prazo dos programas de intervenção na comunidade, e realçam o papel das intervenções preventivas de educação contínua e de atividade física regular, para o processo de redução dos indicadores de risco metabólico desde a infância. Palavra-chave: Crianças; Perfil lipídico; Obesidade; Programa de intervenção .
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Presentación. A continuación presentamos la entrevista que la Directora, una representante del Comité Editorial y el Editor de Perspectivas Rurales realizaron al Rector de la Universidad Nacional de Costa Rica, Dr. Jorge Mora. En el transcurso se puso particular énfasis en el tema central de esta entrega: Apertura y pequeña producción agrícola.
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Introducción El objetivo del presente artículo es analizar los efectos del proceso de globalización y de reformas de las economías sobre la producción agrícola y la pobreza de los campesinos de Honduras, México y Nicaragua. En tal virtud, el análisis de la política de ajuste estructural aplicada en los tres países seleccionados y sus efectos sobre la rentabilidad agropecuaria y el comportamiento de la producción, se estudian en la segunda sección. La mayoría de los indicadores sociales muestra un deterioro en el sector rural de los tres países. Este tema, asociado a la pobreza, es examinado en la tercera sección. Se finaliza con algunas conclusiones del análisis realizado.
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The increased emphasis within Europe on the role of second-tier cities has implications for the ways in which these urban centres are considered within national spatial planning strategies. In centralised, monocentric states like Ireland, there has been a general ambivalence towards urban policy for cities outside the capital city, and historically this has prevented the development of a strong, diversified urban hierarchy undermining prospects for balanced regional development. This paper examines the extent to which a new found emphasis on Ireland’s second-tier cities which emerged in the ‘Gateways’ policy of the National Spatial Strategy (NSS, 2002) was matched by subsequent political and administrative commitment to facilitate the development of these urban centres. Following a discussion of the position of second-tier cities in an international context and a brief overview of recent demographic and economic trends, the paper assesses the relative performance of Ireland’s second-tier cities in influencing development trends, highlighting a comprehensive failure to deliver compact urban growth. In this context, the paper then discusses the implications of current development plans for the second-tier cities and proposals for Irish local government reform for securing compact urban development.
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