885 research outputs found
Family Farming and Biodiesel: rural development in Central-Western Brazil
A produção de biodiesel no Brasil iniciou-se em 2005. O Programa Nacional de Produção e Uso do Biodiesel (PNPB) objetivou integrar agricultores familiares como fornecedores de matéria-prima para as indústrias de biodiesel, reduzindo assim a pobreza e promovendo o desenvolvimento rural. A integração de agricultores familiares foi revista devido a predominância da soja na cadeia de produção do biodiesel. Este estudo teve como objetivo comparar os mecanismos institucionais desenvolvidos por agricultores familiares e agentes econômicos em Mato Grosso a partir de dois diferentes estudos que ocorreram entre 2011 e 2013. O contexto teórico da Nova Economia Institucional foi necessário para identificar os mecanismos contratuais e de mercado desenvolvidos – arrendamento de maquinário, adicional de preço, fontes de financiamento e os pacotes tecnológicos – para aumentar a renda familiar e contribuir para o sucesso do PNPB em Mato Grosso. A presença destes mecanismos em diferentes regiões indica a difusão do conhecimento na rede produtiva da soja
Variational Bayesian analysis of survival data using a log-logistic accelerated failure time model
The log-logistic regression model is one of the most commonly used
accelerated failure time (AFT) models in survival analysis, for which
statistical inference methods are mainly established under the frequentist
framework. Recently, Bayesian inference for log-logistic AFT models using
Markov chain Monte Carlo (MCMC) techniques has also been widely developed. In
this work, we develop an alternative approach to MCMC methods and infer the
parameters of the log-logistic AFT model via a mean-field variational Bayes
(VB) algorithm. A piecewise approximation technique is embedded in deriving the
VB algorithm to achieve conjugacy. The proposed VB algorithm is evaluated and
compared with typical frequentist inferences and MCMC inference using simulated
data under various scenarios. A publicly available dataset is employed for
illustration. We demonstrate that the proposed VB algorithm can achieve good
estimation accuracy and has a lower computational cost compared with MCMC
methods
EXTREME EVENTS OF PRECIPITATION AND OCCURRENCES OF FLOODING, RUNOFF AND INUNDATION IN THE METROPOLITAN REGION OF CURITIBA, BRAZIL
Extreme precipitation events cause severe damage in both urban and rural areas. The objective of this work was to analyze rainfall variability, understand the dynamics of extreme precipitation events and to find out the occurrence of floods, runoff and inundation in the Metropolitan Region of Curitiba (MRC). Data from 39 rainfall stations distributed in the MRC area were used, as well as data by municipality of occurrence of flooding, runoff or inundation, from 1976 to 2018. Extreme precipitation events were identified in all months, most frequently in the summer. Totaling 48 decrees of emergency or public calamity and 397,516 people affected by one of the three socioenvironmental disasters.Extreme precipitation events cause severe damage in both urban and rural areas. The objective of this work was to analyze rainfall variability, understand the dynamics of extreme precipitation events and to find out the occurrence of floods, runoff and inundation in the Metropolitan Region of Curitiba (MRC). Data from 39 rainfall stations distributed in the MRC area were used, as well as data by municipality of occurrence of flooding, runoff or inundation, from 1976 to 2018. Extreme precipitation events were identified in all months, most frequently in the summer. Totaling 48 decrees of emergency or public calamity and 397,516 people affected by one of the three socioenvironmental disasters
Degradabilidade in situ de híbridos de milho e de capim-elefante colhidos em quatro estádios de maturidade
Dentre as forragens, a silagem de milho é amplamente utilizada pelos fazendeiros que visam explorar o máximo do potencial genético dos animais. No entanto, outros volumosos tropicais como o capim-elefante (Pennisetum purpureum) são mais produtivos e, portanto, mais baratos do que a silagem de milho. Nosso objetivo foi comparar a degradabilidade in situ do capim-elefante com a degradabilidade de híbridos de milho, colhidos em quatro estágios de maturidade. O experimento seguiu um delineamento de blocos ao acaso com sub-parcelas. Dois híbridos de milho: AG5011 e ZN8392 foram colhidos com 25, 30, 35 e 40% matéria seca (MS) na planta toda e separados na fração colmo + bainha + folhas e espigas. Capim elefante foi colhido 30, 40, 50 e 60 dias após o corte de nivelamento. As amostras secas e trituradas foram incubadas no rúmen por 0, 6, 12, 24, 48 e 72 h para cálculo da cinética da degradação ruminal da MS e da fibra em detergente neutro (FDN). O avanço da maturidade aumentou os teores de FDN e fibra em detergente ácido (FDA) do capim elefante e reduziu a degradabilidade da MS. Entretanto, a maturidade teve pouco efeito sobre os teores de fibra e a degradabilidade da MS da fração planta dos híbridos de milho. O capim elefante apresentou maior degradabilidade da FDN do que híbridos de milho, e não houve efeito da maturidade sobre a degradabilidade da FDN das duas espécies. A degradabilidade da fibra de capim-elefante não é pior do que a de híbridos de milho e, portanto a escolha da forragem deve ser feita com base em análises econômicas ao invés de assumir um menor potencial de produção em dietas a base de capim elefanteAmong tropical forages, corn silage is largely used by farmers trying to explore the maximum genetic potential from the animals. However, other tropical forages, such as elephant-grass (Pennisetum purpureum), are more productive and therefore cheaper to use than corn silage. Our objective was to compare the in situ degradability of elephant-grass with that from corn hybrids, all harvested at four stages of maturity. The experimental design followed a randomized block design with nested subplots. Two corn hybrids: AG5011, ZN8392 were harvested with 25, 30, 35, and 40% dry matter (DM) in the whole plant, and separated in stem + leaf sheath + leaf blade (stover), and cobs. Elephant-grass was harvested with 30, 40, 50 and 60 days after a leveling cut. Dried and ground samples were incubated in nylon bags inside the rumen for 0, 6, 12, 24, 48 and 72 h to estimate the kinetics of ruminal DM and neutral detergent fiber (NDF) degradation. The advance of maturity increased the NDF and acid detergent fiber (ADF) content in elephant-grass, and reduced its DM degradability. However, maturity had little or no effect on fiber content and DM degradability of corn stover. Elephant-grass had a higher NDF degradability than corn stover, and there was no effect of maturity on NDF degradability of either elephant-grass or corn stover. Fiber degradability of elephant-grass was not worse than that of corn stover, and therefore the choice of forage should be made on economical analysis rather than assuming an intrinsic low production potential for elephant-grass based diet
PLUVIOMETRIC VARIABILITY AND EXTREME PRECIPITATION AND DROUGHTS EVENTS IN THE CENTRAL NORTH MESOREGION OF PARANÁ
Extreme precipitation events cause severe damage in both urban and rural areas. The purpose of this work was to analyze rainfall variability and detect the extremes of precipitation and droughts occurrences and relate them to ENSO phenomena in the Central North Mesoregion of Paraná (MRNCP). We used data from 44 weather stations distributed in the area of the study, from 1976 to 2018. Based on the results, it was identified the precipitation has regional discrepancies, concentrating the highest rainfall in the southern portion. The highest annual precipitation was highly correlated with the periods identified as El Niño, and then in neutrality. There were large occurrences of drought by decent, with emphasis on the winter months, especially in August. High rainfall heights recorded within 24 hours in all regions analyzed, especially in the summer and spring months.Extreme precipitation events cause severe damage in both urban and rural areas. The purpose of this work was to analyze rainfall variability and detect the extremes of precipitation and droughts occurrences and relate them to ENSO phenomena in the Central North Mesoregion of Paraná (MRNCP). We used data from 44 weather stations distributed in the area of the study, from 1976 to 2018. Based on the results, it was identified the precipitation has regional discrepancies, concentrating the highest rainfall in the southern portion. The highest annual precipitation was highly correlated with the periods identified as El Niño, and then in neutrality. There were large occurrences of drought by decent, with emphasis on the winter months, especially in August. High rainfall heights recorded within 24 hours in all regions analyzed, especially in the summer and spring months
Scheduling of a hydro producer considering head-dependency, price scenarios and risk-aversion
In this paper, a mixed-integer quadratic programming approach is proposed for the short-term hydro scheduling problem, considering head-dependency, discontinuous operating regions and discharge ramping constraints. As new contributions to earlier studies, market uncertainty is introduced in the model via price scenarios, and risk aversion is also incorporated by limiting the volatility of the expected profit through the conditional value-at-risk. Our approach has been applied successfully to solve a case Study based on one of the main Portuguese cascaded hydro systems, requiring a negligible computational time
QUANTITATIVE ANALYSIS OF FUTSAL PLAYERS’ ORGANIZATION ON THE COURT
The purpose of this study was to quantify and analyze professional Futsal teams’ organization on the court in shots to goal and tackles situations. Two-dimensional coordinates of 22 players’ positions were obtained during a match between Brazil and Paraguay using a computational tracking system. Team organization in 58 specific situations of shots to goal and 120 tackles were analysed. The variables quantified were teams’ coverage area and distance between teams’ centroids. Results showed that defending team coverage area was greater (
TEMPO PRESENTE E CULTURA DA MÍDIA: CONVERGÊNCIA E INTELIGÊNCIA COLETIVA NA SOCIEDADE CONTEMPORÂNEA
Este artigo aborda a Cultura da Mídia, enfatizando a Convergência e a Inteligência Coletiva gerada por essa cultura, realizando um trabalho de História do Tempo Presente a partir do estudo de dois casos concretos que se desenrolaram ao longo de 2011: a polêmica sobre a coleção outono/inverno da Arezzo e as revoltas e rebeliões em dois países no Oriente Médio. Em ambos os casos o espaço de discussão e organização das manifestações foi o ciberespaço. Analisamos como a Cultura da Mídia se desenvolve como um lócus de organização de inteligência coletiva e seu poder no cotidiano da sociedade contemporânea.
Squamous cell carcinomas with myiasis, a new trend?
Importância do problema: Este artigo se propõe a descrever dois casos de miíase em feridas neoplásicas de carcinomas escamosos, uma associação rara que vem se tornando comum. Comentários: Esta associação deve-se as altas prevalências de HPV, baixas condições socioeconômicas e de higiene, além do manejo inadequado de feridas e do descaso dos homens para com sua saúde, os principais afetados quando o assunto é câncer orofaríngeo e de pênisRelevance: This article intends to describe two cases of myiasis on squamous cells neoplasic wounds, a rare association that are becoming more easily seen nowadays. Comments: This association due to high HPV serum prevalences, low social and hygiene conditions, in addition to the precarious wounds care and men´s health seek relapse, the mainly affected when the issue is oropharynx and penis cancers
A multibiomarker approach in the caged neotropical fish to assess the environment health in a river of central Brazilian Cerrado
Embargo until 19 August 2022.Water safety is a world-wide concern and several efforts have been made in order to ensure the conservation of aquatic ecosystems. Water quality monitoring must be performed with an integrated approach using biomonitor organisms allied to water parameters. Nonetheless, very few studies have focused on biomarker responses in neotropical fish, especially in the freshwater ecosystem of Brazilian Cerrado savanna. In present study, the active biomonitoring of the João Leite river (central Brazilian Cerrado river) was performed through the evaluation of biomarker responses in caged Astyanax lacustris in combination with land use classification and analysis of water parameters. Caged fish were exposed for seven days at four sites along the river and two control groups were kept in a tank under controlled conditions. Results showed that pasture was the predominant land use in the João Leite river basin (54.07%), followed by natural vegetation (34.92%) and other kind of land use (11.01%). Water analyses showed metal concentrations (Mn and Fe) above the maximum allowed by Brazilian regulation, with particularly higher concentrations at Site 2 (near to pasture area). Biomarker responses did not show significant differences for somatic and mutagenic biomarkers between sites. However, the comet assay showed high DNA damage at Sites 2 and 3, indicating genotoxic effects in caged fish at pasture areas. Histopathological analysis showed highest frequency of leukocyte infiltration in liver of fish from Site 2, confirming the ecotoxic effects on A. lacustris in streams impacted by grazing activities. DNA damage and leukocyte infiltration in fish hepatic tissues were sensitive biomarkers in the neotropical fish A. lacustris to assess the environment health of the Cerrado river. These results showed the importance of using a multibiomarker approach in environmental risk assessment, especially in areas more at risk from anthropogenic pollution.acceptedVersio
- …