6,257 research outputs found

    Short term fluctuations of zooplankton abundance during autumn circulation in two reservoirs with contrasting trophic state

    Get PDF
    Zooplankton community in the reservoirs of Maranhao and Santa Luzia (Portugal) were studied during the autumn stratification breakdown and the weeks before it. The results from water transparency, chlorophyll-a and total phosphorus concentrations, calanoid to cyclopoid copepods ratio and zooplankton abundance confirm the different trophic state of both studied reservoirs: mesotrophic-eutrophic (Maranhao) and oligotrophic-mesotrophic (Santa Luzia), as previous studies have reported. Using Copidodiaptomus numidicus to compare both studied reservoirs, we found higher egg production rates in Maranhao than in Santa Luzia. Nevertheless, no relationship was ever found between zooplankton (abundance or egg production rate) and environmental variables (temperature and chlorophyll-a), which may suggest that wide and complex range of factors, abiotic as much as biotic, are involved in zooplankton dynamics during the autumn circulation period.La comunidad zooplanctónica de los embalses de Maranhao y Santa Luzia (Portugal) fue estudiada durante la ruptura de la estratificación otoñal y las semanas previas. Los resultados de transparencia del agua, concentración de clorofila-a y concentración de fósforo total, así como la razón entre copépodos calanoides y ciclopoides y la abundancia de zooplancton confirman el diferente estado trófico entre ambos embalses: mesotrófico-eutrófico (Maranhao) y oligotrófico-mesotrófico (Santa Luzia), como estudios previos habían mostrado. Utilizando al copépodo Copidodiaptomus numidicus para comparar ambos embalses, se ha observado una mayor tasa de producción de huevos en Maranhao que en Santa Luzia. Sin embargo, en ningún caso se ha encontrado una relación entre el zooplancton (abundancia o tasa de producción de huevos) y las variables ambientales (temperatura y concentración de clorofila-a), por lo que se sugiere que una amplia y compleja gama de factores, tanto bióticos como abióticos, deben de estar involucrados en la dinámica del zooplancton durante el periodo de circulación otoñal

    DETERMINANTS OF TECHNICAL EFFICIENCY IN AGRICULTURE AND CATTLE RANCHING: A SPATIAL ANALYSIS FOR THE BRAZILIAN AMAZON

    Get PDF
    The determinants of technical efficiency in agriculture and cattle ranching are closely related with the debate involving the conservation-development trade-off in the Brazilian Amazon. Concerned with balancing development and environmental conservation, policy makers and academics have emphasized the importance of choosing ways of selecting areas where land use restrictions would be established. In order to understand the relationship between spatial patterns of deforestation and the associated distribution and characteristics of economic activity, issues regarding technical efficiency are clearly important. This paper aims to identify the socio-economic and environmental determinants of technical efficiency in agriculture and cattle ranching in the Brazilian Amazon emphasizing their relationship with spatial processes of deforestation and development. The study is structured in two parts. The first part is concerned with measuring technical efficiency for agriculture and cattle ranching in each geographical unit focusing on the production relationship between inputs and outputs. The second one focuses on the variation in the efficiency measure explained by exogenous factors and includes the spatial analysis. We adopt the model proposed by Battese and Coelli (1995) where the production function and the exogenous effects influencing technical efficiency are estimated simultaneously.

    Spatial distribution of the positivity of Schistosomiasis mansoni in Maranhao State, Northeastern Brazil, from 2007 to 2016

    Get PDF
    Schistosomiasis is considered one of the Neglected Tropical Diseases (NTDs), which affects around 240 million people worldwide. In Brazil, Schistosomiasis mansoni has been registered in 19 states, predominantly in rural areas. This study aimed to analyze the spatial distribution of Schistosomiasis mansoni cases in the Maranhao State from 2007 to 2016, as well as the temporal trend over this period. The data were obtained from secondary sources: Schistosomiasis Control Program of Maranhao (PCE-MA) and Information System for Notifiable Diseases (SINAN). The State Health Regions (HRs) were considered analysis units. Maranhao had a positivity rate of 3.8 for the period. The Regions that presented the highest percentages of positivity in the state were Pinheiro (7.92), Ze Doca (3.30), and Viana (3.10). Municipalities such as Bacuri, Serrano do Maranhao, and Bequimao, located in the Pinheiro HR, showed positivity rates of 16.56, 13.31, and 11.01 respectively. The spatial analysis of schistosomiasis cases showed that Maranhao has two main centers for the spread of the disease, both located in the northern portion of the state, namely the Baixada Maranhense and the east coast. This study concluded that the positivity of Schistosomiasis mansoni in Maranhao was stable over the analyzed period. The state still maintains the Baixada Maranhense micro-region as an important area for the spread of the disease reaching socially vulnerable population groups

    Geographic patterns of land use and land intensity in the Brazilian Amazon

    Get PDF
    Using census data from the Censo Agropecuario 1995-96, the authors map indicators of current land use, and agricultural productivity across Brazil's Legal Amazon, These data permit geographical resolution about ten times finer than afforded by"municipio"data, used in previous studies. The authors focus on the extent, and productivity of pasture, the dominant land use in Amazonia today. Simple tabulations suggest that most agricultural land in Amazonia yields little private economic value. Nearly ninety percent of agricultural land is either devoted to pasture, or has been out of use for more than four years. About forty percent of the currently used pastureland, has a stocking ratio of less that 0.5 cattle per hectare. Tabulations also show a skewed distribution of land ownership: almost half of Amazonian farmland is located in the one percent of properties that contain more than two thousand hectares. Multivariate analyses relate forest conversion, and pasture productivity to precipitation, soil quality, infrastructure, and market access, proximity to past conversion, and protection status. The authors find precipitation to have a strong deterrent effect on agriculture. The probability that land is currently claimed, or used for agriculture, or intensively stocked with cattle, declines substantially with increasing precipitation levels, holding other factors (such as road access) constant. Proxies for land abandonment are also higher in high rainfall areas. Together these findings suggest that the wetter Western Amazon is inhospitable to exploitation for pasture, using current technologies. On the other hand, land conversion, and stocking rates are positively correlated with proximity to past clearing. This suggests that in the areas of active deforestation in eastern Amazonia, the frontier is not :hollow:, and land use intensifies over time. But this area remains a mosaic of lands with higher, and lower potential agricultural value.Agricultural Knowledge&Information Systems,Climate Change,Wetlands,Water Conservation,Environmental Economics&Policies,Climate Change,Wetlands,Environmental Economics&Policies,Agricultural Knowledge&Information Systems,Forestry

    The oldest Brazilian snakes from the cenomanian (Early Late Cretaceous)

    Get PDF
    South American Mesozoic snake diversity is mostly represented by genera from the Cenomanian (Najash), Santonian- Campanian (Dinilysia), and Campanian-Maastrichtian (Alamitophis, Patagoniophis, Rionegrophis, and Australophis) of Patagonia, Argentina. In this paper, we describe a new snake genus and species, Seismophis septentrionalis, from the Cenomanian (early Late Cretaceous) of the Alcântara Formation, Maranhão, northeastern Brazil. The new snake comprises a posteriormost trunk vertebra and possibly a poorly preserved midtrunk vertebra. Both vertebrae share small size, zygosphene moderately thick with a rectilinear roof, absence of paracotylar foramina, presence of parazygantral foramina, and strongly marked parasagittal ridges of the neural arch. The new snake is here considered of uncertain systematic affinities, but probably close to the limbed snake Najash rionegrina. Although the material is very fragmentary and the systematic assignment is still unresolved, this snake represents the oldest, as well as probably the most primitive snake from Brazil.Fil: Hsiou, Annie. Universidade de Sao Paulo; BrasilFil: Albino, Adriana Maria. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Medeiros, Manuel. Universidade Federal Do Maranhao; BrasilFil: Santos, Ronny. Universidade Federal Do Maranhao; Brasi

    Polluting emissions and GDP : decoupling evidence from brazilian states

    Get PDF
    We provide a comprehensive analysis of the relationship between greenhouse gas (GHG) emissions and GDP in Brazil using both aggregate and state-level data. The trend or Kuznets elasticity is about 0.8 for Brazil, higher than that in advanced countries but below that of major emerging markets. The elasticity is somewhat higher for consumption-based emissions than for production-based emissions, providing evidence against the “pollution haven” hypothesis. Additional evidence comes from state-level data analysis where one can observe a great deal of heterogeneity but also some hope as far as decoupling is concerned. In addition to the trend relationship between emissions and output, we find that there does not seem to exist a cyclical relationship holding in Brazil at the aggregate level (despite having become more procyclical over time), but it does exist in a few states.info:eu-repo/semantics/publishedVersio

    The user structure in Brazil's tropical rain forest

    Get PDF
    This paper presents quantitative evidence on the relationship between forest conversion and the productivity of agropastoral activities in the Legal Amazon. The extraction of timber products such as wood, fuelwood and charcoal is related to the process of agropastoral expansion in this region with the aim of providing physical coefficients to define intersectoral connections in Brazil's economy. The paper is organized as follows. Section I makes a geographical characterization of the original vegetation types of the region according to its principal geopolitical subdivisions. Section II presents evidence on deforestation rates and gross areas affected. Section III describes the principal sources of deforestation. Section IV describes sectoral activities and land occupation patterns distinguishing between forested and non-forested areas. Section V analyses major determinants of productivity in agropastoral activities following this broad vegetation distinction. Section VI provides gross estimates of wood removal associated with agropastoral expansion, and compares this with wood and fuel production figures. Conclusions are presented in Section VII.

    Protecting Brazil's tropical forest: a CGE analysis of macroeconomic, sectoral, and regional policies

    Get PDF
    The 'deforestation problem' in Brazil consists of a variety of interrelated issues, of which this paper identifies a regional, sectoral and macroeconomic dimension. Using a regionally and sectorally disaggregated general equilibrium model of Brazil, it is shown that macroeconomic reform is complementary to conservation policies. Therefore, if not for other reasons, macroeconomic reform is urgently needed to provide an adequate framework for microeconomic conservation policies to be effective. The analysis also shows that regional land taxes in the Amazon outperform the reduction of fiscal incentives for agriculture, both with regards to ecological effectiveness and efficiency. Finally, the results do not support claims for compensation payments.deforestation,public policy,general equilibrium analysis,Brazil

    Prevalence of chronic kidney disease and comorbidities in isolated African descent communities (PREVRENAL): methodological design of a cohort study

    Get PDF
    Background: Chronic kidney disease (CKD) is considered a serious public health problem, both in Brazil and worldwide, with an increasing number of cases observed inrecent years. Especially, CKD has been reported to be highly prevalent in those of African descent. However, Brazil lacks data from early-stage CKD population studies, and the prevalence of CKD is unknown for both the overall and African descent populations. Hence, the present study aims to estimate the prevalence of early-stage CKD and its associated risk factors in African-Brazilians from isolated African-descent communities. Herein, the detailed methodology design of the study is described. Methods: This population-based, prospective, longitudinal, cohort study (PREVRENAL) is performed in three stages: first, clinical, nutritional, and anthropometric evaluationsmeasurements of serum and urinary markersand examinations of comorbidities were performed. Second, repeated examinations of individuals with CKD, systemic arterial hypertension, and/or diabetes mellitusimage screeningand cardiac risk assessment were performed. Third, long-term monitoring of all selected individuals will be conducted (ongoing). Using probability sampling, 1539 individuals from 32 communities were selected. CKD was defined asaglomerular filtration rate (GFR) 30 mg/day. Discussion: This study proposes to identify and monitor individuals with and without reduced GFR and high albuminuria in isolated populations of African descendants in Brazil. As there are currently no specific recommendations for detecting CKD in African descendants, four equations for estimating the GFR based on serum creatinine and cystatin C were used and will be retrospectively compared. The present report describes the characteristics of the target population, selection of individuals, and detection of a population at risk, along with the imaging, clinical, and laboratory methodologies used. The first and second stages have been concluded and the results will be published in the near future. The subsequent (third) stage is the long-term, continuous monitoring of individuals diagnosed with renal abnormalities or with CKD risk factors. The entire study population will be re-evaluated five years after the study initiation. The expectation is to obtain information about CKD evolution among this population, including the progression rate, complication development, and cardiovascular events.Research Support Foundation of Maranhao (Fundacao de Amparo a Pesquisa do Maranhao - FAPEMA)Univ Fed Maranhao, Kidney Dis Prevent Ctr, Sao Luis, MA, BrazilUniv Fed Maranhao, Dept Med 1, Sao Luis, MA, BrazilUniv Fed Maranhao, Dept Publ Hlth, Sao Luis, MA, BrazilUniv Fed Maranhao, Kidney Dis Prevent Ctr, Sao Luis, MA, BrazilUniv Fed Maranhao, Dept Physiol Sci, Sao Luis, MA, BrazilUniv Sao Paulo, Ribeirao Preto Sch Med, Dept Pathol & Radiol, Ribeirao Preto, SP, BrazilUniv Estado Rio De Janeiro, Dept Internal Med, Rio De Janeiro, RJ, BrazilUniv Fed Sao Paulo, Paulista Sch Med, Discipline Nephrol, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Paulista Sch Med, Discipline Nephrol, Sao Paulo, SP, BrazilWeb of Scienc

    Market analysis for Acrean timbers

    Get PDF
    In the state of Acre (Brazil), keys of development are the valorization of natural resources, which include non-ligneous and timber products. The need to develop a sustainable wood industry lead to assess markets that can be targeted from Acre in an sustainable and economic way. The objective of this analysis is so to highlight the opportunities and the marketing strategies that are the most suitable from a timber business point of view, in the specific context of Acre. Care should be taken that all the conclusions that can be interpreted from this work are valid from a timber business point of view, but these market considerations don’t necessarily prevail on other considerations, such as social or political ones. From a general point of view, Acre State, despite its remote location, is not independent of the globalization process. This means that the market analysis is required to start from the world level markets, and has to deepen progressively down to national, regional and local levels, in order to correctly isolate which are the competitive advantages and disadvantages of the specific Acrean context.
    corecore