Orientação regional das exportações brasileiras de arroz, 2001 a 2011.

Foi utilizado o Índice de Orientação Regional (IOR), que indica a direção que as exportações de arroz vêm tomando ao longo de um período. Os blocos considerados para este cálculo são Oriente Médio, União Européia e África, em virtude de sua importância, em termos de comércio no cenário internacional e como potenciais destinos das exportações brasileiras de arroz

Formação de preços agrícolas: uma análise microeconômica do mercado de feijão.

O que busca esse trabalho é derivar a formação de preços do feijão e explicar o comportamento do mercado no ano de 2007 e início de 2008 identificando possíveis comportamentos oportunistas dos agentes da cadeia do feijão

Defining quantitative stream disturbance gradients and the additive role of habitat variation to explain macroinvertebrate taxa richness

Most studies dealing with the use of ecological indicators and other applied ecological research rely on some definition or concept of what constitutes least-, intermediate- and most-disturbed condition. Currently, most rigorous methodologies designed to define those conditions are suited to large spatial extents (nations, ecoregions) and many sites (hundreds to thousands). The objective of this study was to describe a methodology to quantitatively define a disturbance gradient for 40 sites in each of two small southeastern Brazil river basins. The assessment of anthropogenic disturbance experienced by each site was based solely on measurements strictly related to the intensity and extent of anthropogenic pressures. We calculated two indices: one concerned site-scale pressures and the other catchment-scale pressures. We combined those two indices into a single integrated disturbance index (IDI) because disturbances operating at both scales affect stream biota. The local- and catchment-scale disturbance indices were weakly correlated in the two basins (r = 0.21 and 0.35) and both significantly (p \u3c 0.05) reduced site EPT (insect orders Ephemeroptera, Plecoptera, Trichoptera) richness. The IDI also performed well in explaining EPT richness in the basin that presented the stronger disturbance gradient (R2 = 0.39, p \u3c 0.001). Natural habitat variability was assessed as a second source of variation in EPT richness. Stream size and microhabitats were the key habitat characteristics not related to disturbances that enhanced the explanation of EPT richness over that attributed to the IDI. In both basins the IDI plus habitat metrics together explained around 50% of EPT richness variation. In the basin with the weaker disturbance gradient, natural habitat explained more variation in EPT richness than did the IDI, a result that has implications for biomonitoring studies. We conclude that quantitatively defined disturbance gradients offer a reliable and comprehensive characterization of anthropogenic pressure that integrates data from different spatial scales

Definição de áreas prioritária para recuperação de pastagens degradadas e seu impacto econômico no vale do Araguaia, Estado Goiás.

RESUMO: No intuito de contribuir para um desenvolvimento agrícola e pecuário sustentável no estado de Goiás, este artigo analisa as áreas prioritárias para a recuperação de pastagens no vale do Araguaia, uma região especializada nesta atividade. Para tanto, foram utilizadas as seguintes variáveis: mapa de degradação de pastagens (plataforma Pastagem.org), aptidão agrícola e vulnerabilidade ambiental, requisitos analisados em conjunto em um Sistema de Informações Geográficas. Nossos resultados indicam a existência de mais de 460 mil hectares de pastagem aptos à reforma ou recuperação, podendo gerar um incremento de mais de 2,6 milhões arrobas de proteína bovina. Por ser uma das maiores regiões pecuárias do país e de seu rebanho se alimentar primordialmente de pastagens cultivadas, a recuperação destas se mostra crucial ambiental e economicamente. DEFINITION OF PRIORITY AREAS FOR THE RECOVERY OF DEGRADED PASTURES AND THEIR ECONOMIC IMPACT IN THE ARAGUAIA VALLEY, GOIÁS STATE ABSTRACT: To contribute to sustainable agricultural and livestock development in the state of Goiás, this article analyzes the priority areas for the recovery of pastures in the Araguaia valley, a region specialized in this activity in Brazil (Cerrado biome). For that, the following variables were used: pasture degradation map (Pastagem.org), agricultural aptitude and environmental vulnerability,requirements analyzed together in a Geographic Information System. Our results indicate the existence of more than 460 thousand hectares of pasture suitable for reform or recovery, which may generate an increase of more than 2,6 million arrobas of bovine protein. As it is one of the largest livestock regions in the country and its herd feeds primarily on cultivated pastures, their recovery is crucial in environmental and economic terms

Abastecimento e consumo de arroz no Brasil.

Este estudo visa identificar aspectos relacionados ao abastecimento interno do arroz, levando-se em conta a produção nacional, o consumo, as exportações e as importações do produto. Além disso, busca-se analisar os estoques finais ou estoques de passagem das diferentes safras, considerando o tempo de abastecimento assegurado pelas quantidades estocadas ao final de cada safra e o consumo nacional e per capita

Physical training improves cardiopulmonary functional capacity and increases cytokine IL-10 levels in individuals with Chagas disease

Purpose: To evaluate cardiopulmonary functional capacity and the production of cytokines in patients with and without Chagas disease, and with and without hypertension, after short and long-term exercise.Methods: In a case-controlled study, 56 participants who attended the Chagas Disease Laboratory at the State University of Maringa (LDC/UEM) and Basic Health Units (UBS) in Maringa that agreed to participate. The participants were divided into the following groups: 16 with Chagas disease (CHD group), 21 with systemic arterial hypertension (SAH group) and 19 normal individuals without these morbidities (NI group). Each participant performed the 6-min walk test (6MWT), and a 12-week physical training program. Pro-inflammatory and anti-inflammatory cytokines were measured before and after physical training.Results: The CHD group presented good performance in the 6MWT, with no significant differences in distance traveled or perceived exertion (p > 0.05) compared with the NI group. After physical training, the 6MWT results were significantly better, with significant decreases in systolic and diastolic blood pressure, in the SAH group (p = 0.0409; and p = 0.0377, respectively) and NI group (p = 0.0180; and p = 0.0431, respectively) and a significant increase in the levels of the anti-inflammatory cytokine interleukin-10 (IL-10; p < 0.05) in all three groups. The NI group exhibited a significant increase (p < 0.05) in the serum levels of the pro-inflammatory cytokines IL-6, IL-17 and tumor necrosis factor (all p< 0.05).Conclusion: All of the participants presented improvements in cardiopulmonary functional capacity and good prognosis, indicating the protective effect of IL-10 production and the benefits of physical training.Keywords: Chagas disease, Six-minute walk test, Physical training, Cytokines, Cardiopulmonary function capacity, Hypertensio

Densidade da produção de arroz no mundo.

Ao se estudar os países considerados ?mais relevantes? na produção de arroz costuma-se enfocar a questão da quantidade produzida, independentemente da superfície total dos países ou de suas respectivas áreas cultivadas com o produto. Essa análise feita freqüentemente possui um viés de privilegiar países com maiores extensões territoriais, pelo fato de não levar em conta a superfície total dos países produtores. Assim, o presente trabalho visa identificar países que, mesmo não sendo grandes produtores de arroz em termos de volume total, possuem uma presença forte do produto na economia local e nacional

Fatores que determinam a estrutura e distribuição das comunidades de invertebrados bentônicos em uma bacia hidrográfica tropical

We used the das Velhas River basin in southeastern Brazil as a study unit to evaluate the role of various physical and chemical variables and the state of conservation in determining the structure and distribution of benthic macroinvertebrate communities. The habitats were characterized through the use of a rapid evaluation protocol, the examination of the granulometric composition of the sediments, and the precipitation in the sub-basins of the segments studied. The taxonomic structure was determined, Shannon-Wiener and Simpson diversity indexes, taxonomic richness, % EPT and % Chironomidae for the benthic assemblages. The results corroborated the importance of habitats in spatial structuring, the importance of the hydrological regime in temporal structuring, and the state of conservation as the main structuring agents of benthic macroinvertebrate assemblages. Key words: biological metrics, bioindicators, protected areas, environmental impact.Foi utilizada a bacia hidrográfica do Rio das Velhas, sudeste do Brasil, como unidade de estudo para avaliar o papel das variáveis físicas e químicas além do estado de conservação na determinação da estrutura e distribuição das comunidades de macroinvertebrados bentônicos. A caracterização dos habitats foi realizada através da utilização de um protocolo de avaliação rápida, da determinação da composição de granulométrica dos sedimentos e da precipitação nas sub-bacias hidrográficas dos segmentos estudados. Foi determinada a estrutura taxonômica das comunidades bentônicas através dos índices de diversidade de Shannon-Wiener e Simpson, além da riqueza taxonômica, % EPT e % Chironomidae. Os resultados encontrados corroboraram a importância dos habitats na estruturação espacial, do regime hidrológico na estruturação temporal e o estado de conservação como o principal agente de estruturação das comunidades de macroinvertebrados bentônicos. Palavras-chave: parâmetros biológicos, bioindicadores, áreas de proteção ambiental, impacto ambiental

Is the diet of a typical shredder related to the physical habitat of headwater streams in the Brazilian Cerrado?

Macroinvertebrates are important for processing leaf detritus in temperate streams, but studies about their role in tropical streams often present conflicting results. Via digestive tract analyses, we assessed the diets of Phylloicus sp. larvae (Trichoptera: Calamoceratidae), collected from streams of two southeastern Brazil river basins (Araguari, Sao Francisco). We classified gut contents as coarse particulate organic matter (CPOM), fine particulate organic matter (FPOM), algae, animal tissue, vascular plant tissue and mineral material. We hypothesized that the diets of Phylloicus larvae would be related to the physical habitat of the streams (e.g., riparian vegetation, organic matter availability and morphological characteristics), larval size and river basin. Although FPOM content predominated in both basins, we found greater CPOM content in Phylloicus larvae of Upper Sao Francisco sites, and this food item was related to greater riparian vegetation canopy density. The FPOM content was greater in larvae of Upper Araguari sites, and this food item was correlated with greater instream brush cover. Algae, animal tissue, vascular plant tissue and mineral material were very rare in the digestive tracts, and therefore could not be explained. These results indicate the importance of riparian vegetation structure in modulating feeding habitats of macroinvertebrates. We conclude that the Phylloicus larvae had more flexibility in what they eat than we might expect based on their traditional classification as shredders. Therefore, trusting in published classifications, ignoring regional or local differences, may be inaccurate. Instead, regional studies of feeding habits are needed for accurate classifications of invertebrate taxa into trophic guilds

Importance of environmental factors for the richness and distribution of benthic macroinvertebrates in tropical headwater streams

An understanding of the interactions among local environmental factors (e.g., physical habitat and water quality) and aquatic assemblages is essential to conserve biodiversity in tropical and subtropical headwater streams. We evaluated the relative importance of multiple physical and chemical habitat variables that influence the richness of Ephemeroptera, Plecoptera, and Trichoptera (EPT) assemblages in wadeable Brazilian Cerrado (savanna) streams. We sampled macroinvertebrate assemblages and quantified physical and chemical habitat in 79 randomly selected sites in 2 Cerrado basins in southeastern Brazil. The environmental variables selected by multiple regression models (MLRs) via corrected Akaike Information Criteria (AICc) contributed significantly to variation in EPT taxon richness. The variance explained by physical-habitat variables was slightly greater in the Upper São Francisco Basin (adjusted R² = 0.53) than in the Upper Araguari Basin (adjusted R² = 0.46), and both were greater than the variance explained by a combined basin model (adjusted R² = 0.39). Physical-habitat variables were more important than water-quality variables in structuring EPT genera in streams with catchments dominated by agriculture or pasture land uses. Regional models can be improved by incorporating basin-specific information to refine biological assessments and to provide better understanding of the interactions that maintain biodiversity in stream networks.Keywords: Hydromorphology, Physical habitat, Cerrado headwater streams, EPT assemblages, Macroinvertebrate bioindicators, Stream conservatio