1000 resultados para Brazilian semiarid


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Different species of Panicum, including P. dichotomiflorum,have been reported as a cause of photosensitization in sheep, horses, cattle and goats. An outbreak of hepatogenous photosensitization occurred in 3 flocks of hair sheep in the Brazilian semiarid region. Eighty one out of 365 sheep were affected and 39 died. The main affected animals were nursing lambs and sheep younger than one year old. Donkeys, goats and cattle grazing in the same pasture were not affected. Clinical signs were edema of the head, followed by dermatitis, mainly in the face, ears, and croup, ocular discharge, corneal opacity with blindness, and redness of the coronary band and hoof. At necropsy of one affected lamb the liver was yellowish. Upon histologic examination scattered necrotic hepatocytes were observed in the liver and focal areas of necrosis of myocytes appeared in the heart. Samples of P. dicotomiflorum were analyzed by TLC and those containing saponins were isolated by HPLC using RP-C18 column and eluted with a mixture of MeOH and H2O. The isolated compounds were submitted to ¹H and 13C NMR spectroscopy. Reactions were positive to furostanol saponins with the same Rf of the standard protodioscin (0.21) and methylprotodioscin (0.32). The spectroscopic results indicated a mixture of (25R)- and (25S)-protodioscin isomers in a proportion of 3:1, and methylprotodioscin.

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Focal symmetrical encephalomalacia (FSE) is the most prominent lesion seen in the chronic form of enterotoxemia by Clostridium perfringens type D. This paper reports FSE in sheep in Brazil. Six deaths occurred within a seven days period in a flock of 70, four to 30-month-old Santa Inês sheep in the state of Paraíba in the Brazilian semiarid. The flock was grazing a paddock of irrigated sprouting Cynodon dactylon (Tifton grass), and supplemented, ad libitum, with a concentrate of soybean, corn and wheat. Nervous signs included blindness and recumbence. A 19 month-old sheep was examined clinically and necropsied after a clinical course of three days. Gross lesions were herniation of the cerebellar vermis and multifocal, bilateral, symmetric brownish areas in the internal capsule, thalamus and cerebellar peduncles. Histologic lesions were multifocal, bilateral malacia with some neutrophils, swelling of blood vessels endothelium, perivascular edema, and hemorrhages. The flock was vaccinated, before the outbreak, with only one dose of Clostridium perfringens type D vaccine. Two factors are suggested to be important for the occurrence of the disease: insufficient immunity due to the incorrect vaccination; and high nutritional levels by the supplementation with highly fermentable carbohydrates.

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Quais condições permitiram que o Projeto de Transposição de Águas do Rio São Francisco deixasse de figurar no imaginário daqueles que o defendiam, como o vinha sendo desde os idos do período imperial, e, começasse a ser efetivamente implementado somente em 2007? Responder a esta questão corresponde ao objetivo principal deste estudo. Para tal, o Projeto São Francisco, como também é conhecido, foi analisado à luz do modelo de multiple streams, concebido por John Kingdon (2003), orientado para a compreensão sobre como algumas questões passam a fazer parte da agenda de governo, recebendo atenção dos formuladores de políticas públicas, enquanto outras são ignoradas. Por meio do modelo de multiple streams, foi possível apontar os principais diagnósticos e alternativas historicamente apresentados para a região do semiárido brasileiro, frente à questão dramática das secas recorrentes. Além disso, foi estruturado o complexo jogo político da transposição, caracterizado pelo conflito entre coalizões atuantes em múltiplas arenas decisórias. A partir do mapeamento da forma como os atores políticos se apropriaram dos diagnósticos e alternativas apresentados para a região, com o intuito de impor aos demais as suas crenças sobre qual deve ser o melhor caminho para o desenvolvimento do semiárido, foram identificadas as janelas de oportunidades (policy windows) que tornaram viáveis a execução do projeto de transposição.

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In Brazilian semiarid region, the majority of water bodies are temporary and the biodiversity in these ecosystems is poorly known. The goal of this study was to describe the temporal variation of benthic macroinvertebrates in an intermittent stream in the Brazilian semiarid region. From March to July of 2009, surveys of benthic macroinvertebrates and water physiochemical parameters were done in a first order stream located at Piranhas-Açu River basin. 25 macroinvertebrates families were found, 21 belonging to Insecta class. The chironomids were the most abundant group during all study period and were represented by 19 genus. The largest densities and taxonomic richness were seen in the drying phase of the stream while the smallest values were found in the period with the heaviest rainfalls ( wet phase ). Only the families Chironomidae and Ceratopogonidae were found during all study period, suggesting that these groups have better adaptations to support floods and droughts. Furthermore, these two groups seemed to be pioneering in this stream. Among the chironomids, Paratendipes dominated the period of floods while Tanytarsus were more abundant in the drying phase . This study showed that hydrological fluctuation is the main force influencing the macroinvertebrate community in this stream, therefore, efforts seeking the conservation and management of Brazilian semiarid water bodies should consider this high natural variability in flow regime

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The decomposition process exercises an extensive control over the carbon cycle, affecting its availability and nutrient cycling in terrestrial ecosystems. The understanding of leaf decomposition patterns above the soil and fine roots decomposition below the soil is necessary and essential to identify and quantify more accurately the flow of energy and matter in forest systems. There is still a lack of studies and a large gap in the knowledge about what environmental variables act as local determinants over decomposition drivers. The knowledge about the decomposition process is still immature for Brazilian semiarid region. The aim of this study was to analyze the decomposition process (on leaves and fine roots) of a mixture of three native species for 12 months in a semiarid ecosystem in Northeast Brazil. We also examined whether the rate of decomposition can be explained by local environmental factors, specifically plant species richness, plant density and biomass, soil macro-arthropods species richness and abundance, amount of litterfall and fine root stock. Thirty sampling points were randomly distributed within an area of 2000 m x 500 m. To determine the decomposition rate, the litterbag technique was used and the data analysis were made with multiple regressions. There was a high degradation of dead organic matter along the experiment. Above ground plant biomass was the only environmental local factor significantly related to leaf decomposition. The density of vegetation and litter production were positively and negatively related to decay rates of fine roots, respectively. The results suggest that Caatinga spatial heterogeneity may exert strong influences over the decomposition process, taking into account the action of environmental factors related to organic matter exposure of and the consequent action of solar radiation as the decomposition process main controller in this region

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This work aims for the evaluation of Cruzeta Irrigated Perimeter, RN, which consists in the efficient use of water for agricultural production. The goal is looking for the available quantity of water for supplying required demands for adequate and economically viable cultures for the region. It is supposed that regional community water is supplied by pipelines from sources located outside of the region. From this study it is recommended the implantation of adequate installments for culture management in accordance with the availability of water resources and others conditionings. It must be considered the intensity of rainy and drought seasons in order to adjust the cultivated area and equipments to be operated, and also, the use of operating models and simulations in order to establish alert levels and eventually, reduction of irrigated area. Based on obtained data it is proposed the cultivation of different types of non-permanent cultures so that temporary cultures would be extensively produced in periods of abundant reservoir storage water permitting the transformation of storage water in storage culture products and few or no production in severe drought periods. This is the basic premise for sustainable agricultural development for Brazilian semiarid region

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This work deals with the life strategy of an endangered annual fish, Hypsolebias antenori (Cyprinodontiformes: Rivulidae), of the Brazilian semiarid region. The eggs of these fish hatch at the onset of the rainy season, grows rapidly and they reproduce during the rainy season. When the water puddles dry out, the entire population dies. The resistant eggs which are buried in the bottom of the dried pools go through diapause stages, during which time the embryonic development becomes temporarily arrested. With the onset of the next rainy season, the eggs hatch and a new generation is formed. Specimens of H. antenori were captured during 2011 and 2013, in temporary water pools located in the hydrographic basin of river Jaguaribe in Ceará, Brazil. Sex ratio, the length-weight relationship, the growth type, first sexual maturity, anatomy and histology of the digestive tract, development of gonads, reproductive strategy, karyotypic pattern of the species, and the conservation status of H. antenori were investigated. The results of this study are presented in the form of eight articles. The first article is about the fish faunal composition of the hydrographic basins of Rio Grande do Norte, Brazil, wherein the record of H. antenori is included. The second article deals with the sex ratio, secondary sexual characteristics of males, the length-weight relationship and the type of growth. Males show a pattern of intense coloration with well developed fins. The sex ratio showed a significant predominance of females (1M:1.7 F). Males were larger in length and weight. The equation of weight and total length relationship was Wt=0.0271Lt3,8937, showing a positively allometric growth, indicating greater increase in weight than in length. The third article discusses the anatomy and histology of the digestive tract of H. antenori. It is considered as a generalist feeder with characteristics of omnivore, which utilizes different food sources. The fourth article discusses the stages and phases of gonad development and type of spawning of H. antenori. The fifth article is about the r reproductive strategy adopted by H. antenori which helps in successful reproduction over a short period of life. The sixth article deals karyotypic pattern of the species, constituting the first cytogenetic contribution to the genus. The seventh article discusses about the risk of extinction of this species which suffers a series of threats, such as, habitat loss through land use, deforestation, construction of reservoirs, pollution due to domestic and industrial sewage, besides pesticides and agrochemicals. Furthermore, decreasing rainfall and intensification of aridity due to global climate changes, interferes with the reproductive cycle. The eighth article deals with aggressive behavior adopted between males and among females during reproduction. All temporary water pools sampled during this study were in high degree of degradation, mainly due to human action. There is a great need for conservation measures to protect the populations of annual fish, including the creation of protected areas in the semiarid ephemeral aquatic environments of Brazil

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Gasteroid fungi include several distinct lineages of basidiomycetes that were grouped by presenting some striking features in common like angiocarpic development and passive release of basidiospores. For a long period these fungi were accomodate in Gasteromycetes class. However, biochemistry and molecular studies showed the polyphyly of this group and curriently this class lies devoid of taxonomic value. These organisms influence the ecology of the various biomes, however, are poorly studied and knowledge of their diversity in neotropical ecosystems remains insufficient, despite studies that have been developed in recent years. The Brazilian semiarid region has many areas with an unexplored mycobiota. Ceará State has many areas of extreme biological importance and for this study three protected areas were chosen: Área de Proteção Ambiental da Serra da Ibiapaba, Parque Nacional de Ubajara and Área de Proteção Ambiental de Baturité. Therefore, the aim of this study was to inventory gasteroid fungi ocorring in these three areas in the semiarid region of Ceará. The expeditions, herborization and analysis of specimes were based in traditional methodology used to identify gasteroid fungi. Were identified 16 species belong to 5 families: Agaricaceae, Clathraceae, Geastraceae, Nidulariceae and Phallaceae. Morganella nuda Alfredo & Baseia is recorded for the second time in the world, Blumenavia angolensis (Welw. & Curr) Dring and Mutinus elegans (Mont.) E. Fisch. corresponds to a first record in the Brazilian Northeastern. Except for Abrachium floriforme (Baseia & Calonge) Baseia & T.S. Cabral and Geastrum lloydianum Rick, all remaining species are new records for Ceará, increasing the list of gasteroid fungi in the region of 3 for 17 species. Identified species were deposited in the collection of the Herbarium of Universidade Federal do Rio Grande do Norte. Although these areas have proved conducive to the study of gasteroid fungi, more efforts are still needed to increase knowledge of these fungi in the region

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Water scarcity is a reality for the inhabitants of the Brazilian semiarid region. The problem, in quantitative terms , is caused due to local climatic conditions due mostly to a water deficit. Qualitatively, results of multiple uses and resulting contamination by human activities. Eutrophication is presented as a threat to the sustainable use of water resources, in order to favor the predominance of dense populations of cyanobacteria, which can be potentially harmful to human health. The aim of this study is to understand the population dynamics of phytoplankton and cyanobacteria to assess water quality of reservoirs Santa Cruz do Apodi and Pau dos Ferros belonging to bacia Apodi Mossoró-RN . Water samples were collected monthly between October 2011 and May 2012 in reservoirs Santa Cruz do Apodi and Pau dos Ferros, in this latter , in Jan/12 we performed a diel profile . The abiotic variables obtained in the field and in the laboratory were: water temperature , dissolved oxygen , pH , turbidity , transparency , total nitrogen and total phosphorus . Phytoplankton samples were collected with a plankton net and bottle of Van dorn . Were performed : identification , quantification , calculation of biovolume , classification into functional groups and index calculation phytoplankton assembly ( Q ) , cyanotoxins were quantified by ELISA . Statistical analyzes supported the evaluation of the dynamics between biotic and abiotic factors. A questionnaire was conducted to examine the conceptions of the population, education professionals and students. The reservoir of Pau dos Ferros, shallow , turbid and eutrophic showed dominance of the functional group SN throughout the sample period . The phytoplankton biomass ranged from 20 to 70 mm ³ . L - 1, the lowest values coincided with the increase of the mixing zone and transparency, which contributed to the occurrence of a change in species composition phytoplankton . The application of the index Q proved relevant, the reservoir of Pau dos Ferros , depending on the species present , was classified ecologically as bad for almost the entire sample period . The reservoir Santa Cruz do Apodi showed low biomass ( 0.04 and 4.31 mm ³ . L - 1 ) and greater diversity in the phytoplankton composition . According to the index assembly (Q ), it showed moderate condition during most of the period influenced by different functional groups of typical meso- eutrophic environment (K S0, H1, C, F , J , E, D and N) . Associations of diatoms and green algae D and X1 succeeded populations of cyanobacteria in periods marked by greater instability in the system , caused by wind or rain. In summary , the occurrence of drought has a direct influence on the hydrological conditions of the reservoirs , in general, these events, reducing the reservoir level is directly related to decreased water quality and increased density of phytoplankton occurring predominance of cyanobacteria , the index Q reflected well to changes in phytoplankton composition , being a good indicator for biomonitoring of reservoirs in this study and survey of previous conceptions showed the need to work on environmental awareness for the preservation of water resources by conducting workshops for Environmental Education

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Environmental changes and their consequences on the global level have challenged the different fields of study to integrate towards effective solutions to minimize and /or equate the negative impacts of these changes in different types of environments. In this context, the Environmental Perception has been a widely used and relevant in studies that consider the relationship between the environment and human actions, by allowing analysis of perceptions, attitudes and values, key influencers of topophilia that resonates in conservation tool. Allied to Environmental Perception, Integrated Analysis of the Landscape is relevant because it allows to analyze in a systematic way the geographical space where all its elements are interrelated in a way that supports needed to understand the complex physical and human environment of a given environment. In this perspective, we have studied the João do Vale Serrano Complex, located in semiarid of Rio Grande do Norte state, which features a set of landscapes with different faces, which are being replaced by various economic activities and disordered population growth, with consequent exploitation the potential of natural resources. This thesis main goal was to combine the Environmental Perception of rural communities to the of Serrano Complex Landscape Analysis as additional criteria for the definition of Priority Areas for Conservation. The perception data were collected through direct observation, questioning, interviews and application forms to 240 people (100 % of occupied households in the mountain community) during the months of february and august 2011, with theoretical and methodological basis Environmental Perception. Integrated Landscape Analysis was performed by GTP (Geosystem - Territory - Landscape) method, using the Geographic Information System (GIS), using the technique of GIS for mapping the landscape. The results showed that respondents have a sense of topophilia by where they live, hold a vast knowledge of the natural resources in this Serrano Complex, and responded positively regarding the choice of an exclusive area for conservation. The Integrated Analysis of Landscape possible to identify the different forms of existing uses and occupations in Serrano Complex, have caused significant changes in space, especially on the plateau where vegetation was virtually replaced by human dwellings and cashew plantations. Through the maps of slope and environmental vulnerability was identified that areas with high slopes (gullies) are limiting factor for occupation by communities and therefore relevant and amenable to conservation, including by being Permanent Preservation Areas. These results, together, made possible to define a map of Priority Areas for Conservation in Serrano Complex, with three priority categories: low, medium and high. Therefore, the use of these additional criteria are relevant for the definition /designation of Priority Areas for Conservation

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Pós-graduação em Agronomia (Energia na Agricultura) - FCA

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Analisou–se o crescimento dos peixes, a composição das espécies e a produtividade de quatro policultivos (P75, P78, P87 e P207), visando melhorar o manejo e a produtividade pesqueira dos pequenos açudes (0,1–5,0ha) do Semi–Árido brasileiro. Simulou–se as condições desses açudes em viveiros com 120 e 5.000 m2 de área, sem renovação de água, utilizando moderada quantidade de adubo e fertilizante. A biomassa inicial variou de 75 a 207kg há–1, sendo formada por: tilápia do Nilo (Oreochromis niloticus), curimatã pacu (Prochilodus argenteus), carpa comum (Cyprinus carpio), tambaqui (Colossoma macropomum) e tucunaré (Cichla ocellaris). Os peixes apresentaram baixo crescimento (< 0,01g g–1d–1) após 75 dias de criação (P78 e 87). O crescimento do tambaqui, da tilápia e da curimatã foi reduzido após 53 dias (P75). Em moderada biomassa, o crescimento do tambaqui foi inferior ao da carpa e da curimatã (P207). A produtividade da tilápia atingiu 720 kg ha–1ano–1 (P78), sendo reduzida para 220 kg ha–1ano–1 devido ao processo reprodutivo (P75 e P207). A produtividade da carpa de 1.600 kg ha–1ano–1 foi superior a dos outros peixes (P87). A biomassa inicial de 75 kg ha–1 (60:30:4:3:3% de tilápia, tambaqui, carpa, curimatã e tucunaré, respectivamente) otimizou o crescimento e a produtividade dos peixes. A utilização de tilápias monossexadas e o fornecimento da alimentação suplementar ao tambaqui tornam–se imprescindíveis ao policultivo.

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Pós-graduação em Agronomia (Proteção de Plantas) - FCA

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Pós-graduação em Agronomia (Proteção de Plantas) - FCA