3,393 research outputs found

    Rainfall Prediction in the State of Paraíba, Northeastern Brazil Using Generalized Additive Models

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    The state of Paraíba is part of the semi-arid region of Brazil, where severe droughts have occurred in recent years, resulting in significant socio-economic losses associated with climate variability. Thus, understanding to what extent precipitation can be influenced by sea surface temperature (SST) patterns in the tropical region can help, along with a monitoring system, to set up an early warning system, the first pillar in drought management. In this study, Generalized Additive Models for Location, Scale and Shape (GAMLSS) were used to filter climatic indices with higher predictive efficiency and, as a result, to perform rainfall predictions. The results show the persistent influence of tropical SST patterns in Paraíba rainfall, the tropical Atlantic Ocean impacting the rainfall distribution more effectively than the tropical Pacific Ocean. The GAMLSS model showed predictive capability during summer and southern autumn in Paraíba, highlighting the JFM (January, February and March), FMA (February, March and April), MAM (March, April and May), and AMJ (April, May and June) trimesters as those with the highest predictive potential. The methodology demonstrates the ability to be integrated with regional forecasting models (ensemble). Such information has the potential to inform decisions in multiple sectors, such as agriculture and water resources, aiming at the sustainable management of water resources and resilience to climate risk

    Use of MODIS Sensor Images Combined with Reanalysis Products to Retrieve Net Radiation in Amazonia

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    In the Amazon region, the estimation of radiation fluxes through remote sensing techniques is hindered by the lack of ground measurements required as input in the models, as well as the difficulty to obtain cloud-free images. Here, we assess an approach to estimate net radiation (Rn) and its components under all-sky conditions for the Amazon region through the Surface Energy Balance Algorithm for Land (SEBAL) model utilizing only remote sensing and reanalysis data. The study period comprised six years, between January 2001–December 2006, and images from MODIS sensor aboard the Terra satellite and GLDAS reanalysis products were utilized. The estimates were evaluated with flux tower measurements within the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA) project. Comparison between estimates obtained by the proposed method and observations from LBA towers showed errors between 12.5% and 16.4% and 11.3% and 15.9% for instantaneous and daily Rn, respectively. Our approach was adequate to minimize the problem related to strong cloudiness over the region and allowed to map consistently the spatial distribution of net radiation components in Amazonia. We conclude that the integration of reanalysis products and satellite data, eliminating the need for surface measurements as input model, was a useful proposition for the spatialization of the radiation fluxes in the Amazon region, which may serve as input information needed by algorithms that aim to determine evapotranspiration, the most important component of the Amazon hydrological balance

    Organic materials, mineral fertilizer and liming effects on yield of flooded rice

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    O sistema de manejo adotado para as áreas produtoras de arroz irrigado na região Norte Fluminense, RJ, tem conduzido a um progressivo desgaste da camada orgânica dos gleissolos. O efeito de alguns componentes do manejo do solo, como a adubação e a calagem, foi o objetivo do presente estudo. O experimento foi conduzido em casa de vegetação, com amostras de dois horizontes (A e Cg) de um solo gley pouco húmico, coletado no vale do Rio São João, RJ, onde foi avaliado o efeito da adição de estrume bovino, palha de arroz, NPK e calagem, mais as interações entre tratamentos, sobre o rendimento do arroz irrigado. Constatou-se que o horizonte superficial A propiciou um melhor desenvolvimento vegetativo e rendimento de grãos, em comparação com o horizonte subsuperficial (Cg). A adubação mineral aumentou o peso de matéria seca da palhada e das raízes e o rendimento de grãos em ambos os horizontes, enquanto o esterco aumentou os valores destes parâmetros apenas no horizonte A. A incorporação de palha aumentou o peso da palhada e das raízes, mas diminuiu o rendimento de grãos no horizonte A, enquanto no subsuperficial (Cg) diminuiu o rendimento da matéria seca da palhada e não permitiu a formação de grãos.The management system adopted in flooded rice fields in the North region of the State of Rio de Janeiro, Brazil, has caused a progressive reduction in the organic layer of gley soils. The pre- sent work investigates the effects of fertilizer and lime on this system. The experiment was carried out in a greehouse, using soil samples of two horizons (A and Cg) of a low humic gley soil from the valley of the São João River, RJ. The effects of addition of cow manure, rice straw, NPK and lime, singly or in combination, on rice yield, were investigated. Results indicated highly significant differences between soil horizons, showing better responses under superficial horizon (A) as compared to the subsuperficial horizon (Cg). Mineral fertilization increased dry matter production of rice tops and grains on both soil horizons, while cattle manure increased these parametres only on the superficial one. Rice straw application also raised dry matter production of rice tops, but decreased grain yeld on superficial horizon, while on subsuperficial one it reduced dry matter production of the tops and did not induce grain formation

    NPG–TRIS Thermal Storage System. Quantification of the Limiting Processes: Sublimation and Water’s Adsorption

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    The NPG–TRIS binary system (NPG = (CH3)2C(CH2OH)2 = 2,2-dimetyl-1,3-propanodiol; TRIS = NH2C(CH2OH)3 = 2-Amino-2-(hydroxymethyl)-1,3-propanediol) was intensively investigated as a thermal energy storage system, due to the reversibility of its phase transitions and their associated energy. An adapted methodology was applied to precisely quantify its sublimation tendency. Relevant thermochemical data were revisited and evaluated using some specific experimental procedures. We also determined that the widely accepted requirement of working in an inert atmosphere to avoid deviations due to hygroscopicity is not necessary. Nevertheless, to take advantage of the energetic properties of the NPG–TRIS system, closed containers will be required to avoid NPG losses, due to its quantitatively determined high sublimation tendency.This study was financially supported by the Basque Government (IT1301-19, IT1364-19) and through the Elkartek18 R&D program, by the University of the Basque Country UPV/EHU (GIU19/019), and by the Ministry of Science and Innovation of Spain (PID2019-106644GB-I00

    Analysis of Precipitation and Evapotranspiration in Atlantic Rainforest Remnants in Southeastern Brazil from Remote Sensing Data

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    The Atlantic Rainforest has been intensely devastated since the beginning of the colonization of Brazil, mainly due to wood extraction and urban and rural settlement. Although the Atlantic Rainforest has been reduced and fragmented, its remnants are important sources of heat and water vapor to the atmosphere. The present study aimed to characterize and to analyze the temporal dynamics of precipitation and evapotranspiration in the Atlantic Rainforest remnants in São Paulo state, southeastern Brazil, for the period from January 2000 to December 2010. To achieve this, global precipitation and evapotranspiration data from TRMM satellite and MOD16 algorithm as well as forest remnant maps produced by SOS Mata Atlântica Foundation and Brazilian National Institute for Space Research (INPE) were used. Results found in this study demonstrated that the use of remote sensing was an important tool for analyzing hydrological variables in Atlantic Rainforest remnants, which can contribute to better understand the interaction between tropical forests and the atmosphere, and for generating input data necessary for surface models coupled to atmospheric general circulation models

    Methods to Evaluate Land-Atmosphere Exchanges in Amazonia Based on Satellite Imagery and Ground Measurements

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    During the last three decades, intensive campaigns and experiments have been conducted for acquiring micrometeorological data in the Amazonian ecosystems, which has increased our understanding of the variation, especially seasonally, of the total energy available for the atmospheric heating process by the surface, evapotranspiration and carbon exchanges. However, the measurements obtained by such experiments generally cover small areas and are not representative of the spatial variability of these processes. This chapter aims to discuss several algorithms developed to estimate surface energy and carbon fluxes combining satellite data and micrometeorological observations, highlighting the potentialities and limitations of such models for applications in the Amazon region. We show that the use of these models presents an important role in understanding the spatial and temporal patterns of biophysical surface parameters in a region where most of the information is local. Data generated may be used as inputs in earth system surface models allowing the evaluation of the impact, both in regional as well as global scales, caused by land-use and land-cover changes

    Speckle tracking echocardiographic deformation indices in Chagas and idiopathic dilated cardiomyopathy : incremental prognostic value of longitudinal strain

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    Background Chagas cardiomyopathy (CDC) is associated with a poor prognosis compared to other car-diomyopathies. Speckle tracking echocardiography (STE), which provides direct assessment of myocardial fiber deformation, may be useful in predicting prognosis. Objective This study assessed STE in CDC and compared with idiopathic cardiomyopathy (IDC), and also examined the incremental prognostic information of STE over left ventricular ejection fraction (LVEF) in these patients. Methods We enrolled 112 patients, age of 56.7 ± 11.8 years, 81 with CDC and 31 with IDC. STE indices were obtained at baseline in all patients. The endpoint was a composite of death, hospitalization for heart failure, or need for heart transplantation. Results Patients with IDC had worse LV systolic function compared to CDC, with LVEF of 34.5% vs 41.3%, p = 0.004, respectively. After adjustment for LVEF, there were no differences in STE values between CDC and IDC. During a median follow-up of 18.2 months (range, 11 to 22), 26 patients met the composite end point (24%). LV longitudinal strain was a strong predictor of adverse events, incremental to LVEF and E/e’ ratio (HR 1.463, 95% CI 1.130–1.894; p = 0.004). The risk of cardiac events increased significantly in patients with GLS > - 12% (log-rank p = 0.035). Conclusions STE indices were abnormal in patients with dilated cardiomyopathy, without differences between CDC and IDC. LV longitudinal strain was a powerful predictor of outcome, adding prognostic information beyond that provided by LVEF and E/e’ ratio

    Barriers and Levels of Physical Activity in Patients With Symptomatic Peripheral Artery Disease: Comparison Between Women and Men

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    This cross-sectional study compared physical activity levels and barriers between 212 men and women with symptomatic peripheral artery disease. Physical activity was objectively measured by an accelerometer. Barriers to physical activity were obtained using a validated questionnaire. Women reported higher amounts of light physical activity (p < .001) and lower moderate–vigorous physical activity (p < .001) than men. Women more often reported barriers such as “not having anyone to accompany” (p = .006), “lack of money” (p = .018), “fear of falling or worsening the disease” (p = .010), “lack of security” (p = .015), “not having places to sit when feeling leg pain” (p = .021), and “difficulty in getting to a place to practice physical activity” (p = .015). In conclusion, women with symptomatic peripheral artery disease presented with lower amounts of moderate–vigorous activity and more barriers to activity than men. Strategies to minimize the barriers, including group actives and nonpainful exercises, are recommended for women with peripheral artery disease
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