CONTEXT: Blood donation results in a substantial loss of iron (200 to 250 mg) at each bleeding procedure (425 to 475 ml) and subsequent mobilization of iron from body stores. Recent reports have shown that body iron reserves generally are small and iron depletion is more frequent in blood donors than in non-donors. OBJECTIVE: The aim of this study was to evaluate the frequency of iron deficiency in blood donors and to establish the frequency of iron deficiency in blood donors according to sex, whether they were first-time or multi-time donors, and the frequency of donations per year. DESIGN: From September 20 to October 5, 1999, three hundred blood donors from Santa Casa Hemocenter of São Paulo were studied. DIAGNOSTIC TESTS: Using a combination of biochemical measurements of iron status: serum iron, total iron-binding capacity, transferrin saturation index, serum ferritin and the erythrocyte indices. RESULTS: The frequency of iron deficiency in blood donors was 11.0%, of whom 5.5% (13/237) were male and 31.7% (20/63) female donors. The frequency of iron deficiency was higher in multi-time blood donors than in first-time blood donors, for male blood donors (7.6% versus 0.0%, P < 0.05) and female ones (41.5% versus 18.5%, P < 0.05). The frequency of iron deficiency found was higher among the male blood donors with three or more donations per year (P < 0.05) and among the female blood donors with two or more donations per year (P < 0.05). CONCLUSIONS: We conclude that blood donation is a very important factor for iron deficiency in blood donors, particularly in multi-time donors and especially in female donors. The high frequency of blood donors with iron deficiency found in this study suggests a need for a more accurate laboratory trial, as hemoglobin or hematocrit measurement alone is not sufficient for detecting and excluding blood donors with iron deficiency without anemia.
Resumo: A qualidade da água utilizada para irrigação é fator primordial na produção agrícola, principalmente no cultivo de hortaliças, como a berinjela, que podem ter seu crescimento e produção comprometidos pela salinidade. Com isso, objetivou-se com este trabalho avaliar o desenvolvimento e a produção de berinjela irrigada com águas de diferentes salinidades. O estudo foi realizado na área experimental do Departamento de Ciências Ambientais e Tecnológicas da Universidade Federal Rural do Semi-Árido (UFERSA), em Mossoró, Rio Grande do Norte. Utilizou-se um delineamento inteiramente casualizado, com quatro tratamentos e quatro repetições. Os tratamentos foram constituídos por quatro níveis de salinidade (0,5; 2,0; 4,0 e 6,0 dS m -1 ). O efeito da salinidade sobre a cultura foi analisado por meio das seguintes variáveis: diâmetro de caule, altura, número de folhas, área foliar, acúmulo de massa seca (caule, folhas, frutos e da parte aérea) e produção de frutos. O aumento da salinidade da água de irrigação afetou negativamente o desenvolvimento e a capacidade de produção da cultura da berinjela. O uso de água com salinidade acima de 0,5 dS m -1 afeta negativamente o desenvolvimento da planta e a produção de frutos de berinjela. Para as condições ambientais em que foi desenvolvido o estudo, a berinjela foi classificada como sensível à salinidade; para cada aumento unitário da salinidade há perda de 13,5% na produção de frutos. Palavras-chave: Estresse salino. Irrigação. Solanum melongena L.Abstract: The quality of water used for irrigation is a main factor for agricultural productivity, mainly in the cropping of vegetables, like eggplant, which growth and yield can be impaired by salinity. Thus, this work had as objective evaluating growth and yield off eggplant irrigated with water of different salinity levels. The trial was carried out at the experimental area of the Environmental and Technological Sciences Department of Universidade Federal Rural do Semi-Árido (UFERSA), in Mossoró, Rio Grande do Norte, Brazil. The experimental design was an entirely randomized with four treatments and four replications. Treatments consisted of four water salinity levels (0.5, 2.0, 4.0 and 6.0 dS m -1 ). Salinity effect on the crop was analyzed through the following variables: stem diameter, plant height, number of leaves, leaf area, dry mass accumulation (stem, leaves, fruits and shoots) and fruit yield. The increase in irrigation water salinity affected negatively growth and production ability of eggplant crop. The use of water with salinity higher than 0.5 dS m -1 affected negatively plant growth and fruit yield of eggplant. For the environmental conditions faced by eggplant in the trial, this plant was classified as sensitive to salinity. Each unitary increase in salinity corresponded to a 13.5% loss in fruit yield.
The Southern Brazilian Continental Shelf (SBCS) is one of the more productive areas for fisheries in Brazilian waters. The water masses and the dynamical processes of the region present a very seasonal behavior that imprint strong effects in the ecosystem and the weather of the area and its vicinity. This paper makes use of the Regional Ocean Modeling System (ROMS) for studying the water mass distribution and circulation variability in the SBCS during the year of 2012. Model outputs were compared to in situ, historical observations and to satellite data. The model was able to reproduce the main thermohaline characteristics of the waters dominating the SBCS and the adjacent region. The mixing between the Subantarctic Shelf Water and the Subtropical Shelf Water, known as the Subtropical Shelf Front (STSF), presented a clear seasonal change in volume. As a consequence of the mixing and of the seasonal oscillation of the STSF position, the stability of the water column inside the SBCS also changes seasonally. Current velocities and associated transports estimated for the Brazil Current (BC) and for the Brazilian Coastal Current (BCC) agree with previous measurements and estimates, stressing the fact that the opposite flow of the BCC occurring during winter in the study region is about 2 orders of magnitude smaller than that of the BC. Seasonal maps of simulated Mean Kinetic Energy and Eddy Kinetic Energy demonstrate the known behavior of the BC and stressed the importance of the mean coastal flow off Argentina throughout the year.
Sea surface temperature (SST) anomalies caused by a warm core eddy (WCE) in the Southwestern Atlantic Ocean (SWA) rendered a crucial influence on modifying the marine atmospheric boundary layer (MABL). During the first cruise to support the Antarctic Modeling and Observation System (ATMOS) project, a WCE that was shed from the Brazil Current was sampled. Apart from traditional meteorological measurements, we used the Eddy Covariance method to directly measure the ocean–atmosphere sensible heat, latent heat, momentum, and carbon dioxide (CO2) fluxes. The mechanisms of pressure adjustment and vertical mixing that can make the MABL unstable were both identified. The WCE also acted to increase the surface winds and heat fluxes from the ocean to the atmosphere. Oceanic regions at middle and high latitudes are expected to absorb atmospheric CO2, and are thereby considered as sinks, due to their cold waters. Instead, the presence of this WCE in midlatitudes, surrounded by predominantly cold waters, caused the ocean to locally act as a CO2 source. The contribution to the atmosphere was estimated as 0.3 ± 0.04 mmol m−2 day−1, averaged over the sampling period. The CO2 transfer velocity coefficient (K) was determined using a quadratic fit and showed an adequate representation of ocean–atmosphere fluxes. The ocean–atmosphere CO2, momentum, and heat fluxes were each closely correlated with the SST. The increase of SST inside the WCE clearly resulted in larger magnitudes of all of the ocean–atmosphere fluxes studied here. This study adds to our understanding of how oceanic mesoscale structures, such as this WCE, affect the overlying atmosphere.
Resumo -O objetivo deste trabalho foi avaliar a eficiência da aplicação do modelo SEBAL em estimar os fluxos de energia em superfície e a evapotranspiração diária, numa extensa área de cultivo de arroz irrigado, no município de Paraíso do Sul, RS, tendo como parâmetros dados do sensor ASTER. As variáveis estudadas constituem importantes parâmetros do tempo e do clima em estudos agrometeorológicos e de racionalização no uso da água. As metodologias convencionais de estimativa desses parâmetros são pontuais e geralmente apresentam incertezas, que aumentam quando o interesse é o comportamento espacial desses parâmetros. Aplicou-se o algoritmo "Surface Energy Balance Algorithm for Land" (SEBAL), em uma imagem do sensor "Advanced Spaceborne Thermal Emission and Reflection Radiometer" (ASTER). As estimativas obtidas foram comparadas com medições em campo, realizadas por uma estação micrometeorológica localizada no interior da área de estudo. As estimativas mais precisas foram as de fluxo de calor sensível e de evapotranspiração diária, e a estimativa que apresentou maior erro foi a do fluxo de calor no solo. A metodologia empregada foi capaz de reproduzir os fluxos de energia em superfície de maneira satisfatória para estudos agrometeorológicos e de rendimento de culturas.Termos para indexação: arroz, calor latente, calor sensível, sensoriamento remoto, uso da água, resolução espacial. Evaluation of heat fluxes and evapotranspiration using SEBAL model with data from ASTER sensorAbstract -The objective of this study was to evaluate the efficiency of SEBAL model in estimating soil surface energy fluxes and daily evapotranspiration for a large area of irrigated rice farms, near the municipality of Paraíso do Sul, RS, Brazil, using data from ASTER sensor. The evaluated variables are important weather and climatic parameters for agrometeorological studies and rationalization of water use. The conventional methodologies for estimating these parameters generally present uncertainties, which increase when concern is in the spatial behavior of such parameters. The Surface Energy Balance Algorithm for Land (SEBAL) was applied in an Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) scene and the estimates were compared to micrometeorological data retrieved from a station located in the studied area. The most accurate modeled parameter estimatives were sensitive heat and evapotranspiration, and the one which presented the highest error was soil heat flux. The adopted methodology was able to reproduce surface energy fluxes for agrometeorological and crop yield studies.Index terms: rice, latent heat, sensitive heat, remote sensing, water use, spatial resolution. IntroduçãoA evapotranspiração é um dos mais importantes fatores mediadores do clima e do tempo, tanto em escala global quanto local, consistindo da ligação entre energia, clima e hidrologia. Estima-se que, por meio da evapotranspiração global, aproximadamente 62% do volume precipitado sobre os continentes retorne à atmosfera (Dingman, 2002), fato que lh...
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