9 research outputs found
Determinação das previsões de temperaturas mínimas e máximas a partir do histórico das previsões de tempo por conjunto do CPTEC
The U.S. Air Force Weather Agency’s mesoscale ensemble: scientific description and performance results
The article of record as published may be located at http://dx.doi.org/10.1111/j.1600-0870.2010.00497.xThis work evaluates several techniques to account for mesoscale initial-condition (IC) and model uncertainty in a
short-range ensemble prediction system based on the Weather Research and Forecast (WRF) model. A scientific
description and verification of several candidate methods for implementation in the U.S. Air Force Weather Agency
mesoscale ensemble is presented. Model perturbation methods tested include multiple parametrization suites, landsurface
property perturbations, perturbations to parameters within physics schemes and stochastic ‘backscatter’ streamfunction
perturbations. IC perturbations considered include perturbed observations in 10 independent WRF-3DVar
cycles and the ensemble-transform Kalman filter (ETKF). A hybrid of ETKF (for IC perturbations) and WRF-3DVar
(to update the ensemble mean) is also tested. Results show that all of the model and IC perturbation methods examined
are more skilful than direct dynamical downscaling of the global ensemble. IC perturbations are most helpful during
the first 12 h of the forecasts. Physical parametrization diversity appears critical for boundary-layer forecasts. In an
effort to reduce system complexity by reducing the number of suites of physical parametrizations, a smaller set of
parametrization suites was combined with perturbed parameters and stochastic backscatter, resulting in the most skilful
and statistically consistent ensemble predictions.This work was funded by the U.S. Air Force Weather Agency
The convergence between for-profit and nonprofit hospitals in the United States
Nonprofit hospitals, Mixed ownership equilibrium, Convergence, L11, L13, L25, L31, L44, I11, I18,
The impact of gender differences on the relationship between satisfaction and loyalty: a case of the Hong Kong mobile phone industry services
The Role of Diet in the Pathogenesis of Cholesterol Gallstones
Cholesterol gallstone disease is a major health problem in Westernized countries and depends on a complex interplay between genetic factors, lifestyle and diet, acting on specific pathogenic mechanisms. Overweigh, obesity, dyslipidemia, insulin resistance and altered cholesterol homeostasis have been linked to increased gallstone occurrence, and several studies point to a number of specific nutrients as risk- or protective factors with respect to gallstone formation in humans, motivating a rising interest in the identification of common and modifiable dietetic factors that put the patients at risk of gallstones or that are able to prevent gallstone formation and growth. In particular, dietary models characterized by increased energy intake with highly refined sugars and sweet foods, high fructose intake, low fiber contents, high fat, consumption of fast food and low vitamin C intake increase the risk of gallstone formation. On the other hand, high intake of monounsaturated fats and fiber, olive oil and fish (ω-3 fatty acids) consumption, vegetable protein intake, fruit, coffee, moderate alcohol consumption and vitamin C supplementation exert a protective role. The effect of some confounding factors (e.g., physical activity) cannot be ruled out, but general recommendations about the multiple beneficial effects of diet on cholesterol gallstones must be kept in mind, in particular in groups at high risk of gallstone formation