8 research outputs found

    A note on upper ocean temperature and salinity at the entrance to the gulf of californiain august 1992

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    Fernández-Barajas et al. (1994) reportan los resultados de mediciones hidrográficas realizadas en la entrada del Golfo de California en agosto de 1992. Durante ese crucero, el CTD se encontraba calibrado inadecuadamente, teniendo como resultado mediciones anómalas de altas temperaturas y bajas salinidades. Fernández-Barajas et al. (1994) incorrectamente atribuyeron estas condiciones anómalas al fenómeno El Niño de 1991- 1993 y a la tormenta tropical Lester. Fernández-Barajas et al. (1994) report results of hydrographic measurements at the entrance to the Gulf of California in August 1992. During this cruise, the CTD was improperly calibrated, and this resulted in anomalously high (low) near-surface temperatures (salinities) being reported. Fernández-Barajas et al. (1994) incorrectly attribute these anomalous surface conditions to the 1991-1993 El Niño and tropical storm Lester

    Modelagem da recomendação de corretivos e fertilizantes para a cultura da soja Modeling lime and fertilizer recommendations for soybean

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    A recomendação de adubação para as culturas agrícolas, no Brasil, é feita com base em tabelas que relacionam a classe de disponibilidade do nutriente no solo com a dose a ser aplicada. Este trabalho apresenta uma alternativa para recomendar corretivos e fertilizantes para a cultura da soja, o SIRSo (sistema de recomendação de corretivos e fertilizantes para a cultura da soja). O princípio desse sistema é o balanço nutricional, ou seja, a recomendação se faz a partir da diferença entre o requerimento de nutrientes pela planta e o suprimento de nutrientes pelo solo, por resíduos orgânicos, por fertilizantes e pela calagem. O sistema considera ainda o fator sustentabilidade, visando manter uma quantidade de nutriente no solo capaz de garantir produtividade mínima em cultivos subseqüentes. Para recomendar calagem, o sistema considera dois métodos: a neutralização do Al3+ e a elevação dos teores de Ca2+ + Mg2+, ou a saturação por bases. O requerimento de nutrientes varia com a produtividade esperada de grãos, com as características do solo e com a taxa de recuperação pela planta do nutriente aplicado ao solo. O suprimento pelo solo depende da disponibilidade do nutriente, estimada a partir da análise de solo e da taxa de recuperação pelo extrator do nutriente aplicado. As comparações entre as recomendações geradas pelo SIRSo e aquelas oriundas das tabelas em uso no País mostram, em geral, que o SIRSo recomenda maior quantidade de nutrientes, principalmente de P e K quando consideradas as maiores produtividades, fato confirmado pela análise de sensibilidade, que mostrou grande variação da dose a ser recomendada desses nutrientes com a produtividade de grãos. Esse fato pode ser considerado como vantagem do SIRSo em relação às tabelas, muitas das quais apresentam pouca ou nenhuma variabilidade das doses em relação à produtividade.<br>Fertilizer recommendations for agricultural crops in Brazil are based on tables that relate indexes of nutrient availability in the soil with the required dose of the nutrient. This study presents an alternative for lime and fertilizer recommendations for soybean, called SIRSo. This lime and fertilizer recommendation system for soybean considers the nutritional balance, i.e., recommendations are based on the difference between plant nutrient requirement and the nutrient supply from the soil through organic residues, fertilizers and liming. The system further takes a sustainability factor into consideration, aiming at the maintenance of soil nutrient levels that ensure a desired minimum yield in subsequent cultivations. The system considers two methods for liming recommendations: Al3+ neutralization and increased Ca2+ + Mg2+ contents or base saturation. Nutrient requirements vary according to the expected grain yield, the soil characteristics and plant recovery rate of the nutrient applied to the soil. The soil supply depends on the estimated nutrient availability based on the soil analysis, and on the recovery rate of the applied nutrient by the extractor. Comparisons of SIRSo-based recommendations with those of the tables used nationwide show that SIRSo generally recommends higher nutrient quantities, mainly for P and K, when the highest yields are considered. This fact was confirmed by the sensitivity analysis, which detected wide variation of the recommended dose for these nutrients according to the grain yield. This fact is considered an advantage of SIRSo over the tables, where recommendations of doses according to the yield are little or not adjustable at all

    Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight

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    From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions. © Copyright
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