MARX E O CAPITAL PORTADOR DE JUROS: uma introdução

The article aims to expose the fundamental lines of the dialectical (negative) movement of interest-bearing capital, following Marx's own lexis. For this, it follows the rigorous presentation from Marx's Capital and its method of exposure (Darstellungweise), especially the beginning of Section V of Book 3, in addition to comparing Marx's first manuscripts on the issue contained in the Theories of Surplus Value. Thus, rather than presenting a new thesis on the subject, the article focuses on the general presentation of the problem, seeking to capture each peculiar moment of interest-bearing capital in Marx's Capital.O artigo tem como objetivo expor as linhas fundamentais do movimento dialético (negativo) do capital portador de juros, seguindo a própria léxis de Marx. Para isso, segue-se a apresentação rigorosa a partir de O Capital de Marx e o seu método de exposição (Darstellungweise), especialmente o início da Seção V do Livro 3, além de cotejar os primeiros manuscritos de Marx sobre o assunto contidos no livro Teorias da Mais-Valia. Dessa forma, mais do que apresentar alguma nova tese sobre o tema, o artigo fixa-se na apresentação geral do problema, buscando captar cada momento peculiar do capital portador de juros em O Capital de Marx

Estudo de hidrolases glicosídicas bacterianas para aplicações biotecnológicas : bioprospecção, produção e imobilização

Orientadores: Hélia Harumi Sato, Roberto RullerTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de AlimentosResumo: A biomassa lignocelulósica é um importante recurso renovável que está prontamente disponível, sendo uma fonte de matéria-prima com alto potencial biotecnológico. Os polissacarídeos complexos que compõem lignocelulose podem ser convertidos em monossacarídeos fermentescíveis, com grande aplicabilidade em diversos bioprocessos industriais. A degradação dos materiais lignocelulósicos pode ser realizada por uma diversidade de vias enzimáticas complexas, onde é requerido um número considerável de enzimas ativas sobre carboidratos. Entre elas, as famílias das celulases e hemicelulases, além de atuarem na hidrólise dos materiais lignocelulósicos, possuem um uso versátil em setores industriais, tais como, nas áreas alimentícia, bebidas e de biocombustíveis. A tese teve como principais objetivos o delineamento de estratégias para a produção de enzimas e coquetéis enzimáticos eficientes para o uso na hidrólise da biomassa vegetal e, a aplicação de técnicas de imobilização para ampliar a utilização de enzimas em escala comercial. Inicialmente, a bioprospecção de novos micro-organismos secretores de enzimas atuantes na biomassa lignocelulósica foi realizada, e dentre as oitenta linhagens de Streptomyces testadas, duas linhagens (F1 e F7) se destacaram por apresentarem elevadas atividades celulolíticas e hemicelulolíticas. Uma abordagem genômica dessas linhagens possibilitou a identificação de 85 hidrolases glicosídicas (GHs) distribuídas em 33 famílias diferentes na linhagem F1, e 100 GHs dispostas em 44 famílias na linhagem F7. Além disso, os dados genômicos das linhagens F1 e F7 também indicaram a presença de genes relacionados à degradação da lignina. Ferramentas estatísticas também foram aplicadas e possibilitaram a ampliação da produção de GHs pela linhagem F1. Com a otimização, elevadas concentrações de GHs foram alcançadas com meio nutriente adicionado de 16,4 g L-1 de farelo de trigo e 10,0 g L-1 de caseína, onde se obteve 9,27 U mL -1 de xilanase e 0,22 U mL -1 de celulase. Para confirmar a diversidade de GHs expressas pela linhagem F1, uma análise por espectrometria de massa foi realizada e observou-se que quanto maior a complexidade da fonte de carbono utilizada, maior foi a gama de proteínas expressas, incluindo vários tipos de celulases e hemicelulases. A eficiência do extrato enzimático produzido pela linhagem F1 foi estudada para a sacarificação da biomassa vegetal e possibilitou um aumento significativo na liberação de açúcares quando adicionado ao extrato celulolítico comercial, indicando que as enzimas secretadas pela Streptomyces sp. F1 podem ser aplicadas para o melhoramento dos atuais coquetéis comerciais. Foi estudada também a criação de métodos de imobilização de enzimas em condições neutras de pH. Os novos suportes produzidos com a agarose foram utilizados para a imobilização de enzimas monoméricas e multiméricas de grande importância biotecnológica. Um estudo mais detalhado explorando os novos suportes e o uso de técnicas de pós-imobilização foi também proposto. O processo desenvolvido aplicando o polímero polietilenimina (PEI) possibilitou a formação de um excelente sistema para imobilizar e estabilizar a ?-glicosidase obtida de Exiguobacterium antarcticum. A ?-glicosidase imobilizada apresentou uma melhora em suas características, incluindo estabilidade térmica e de armazenamento. Além disso, a ?-glicosidase manteve sua atividade elevada mesmo após vários ciclos de hidrólise com celobiose como substratoAbstract: Lignocellulosic biomass is an important renewable resource that is readily available, being a source of raw material with high biotechnological potential. The complex polysaccharides that compose lignocellulose can be converted into fermentable monosaccharides, with great applicability in several industrial bioprocesses. The degradation of lignocellulosic materials can be accomplished by a variety of complex enzymatic pathways, where a considerable number of carbohydrate active enzymes are required. Among them, the families of cellulases and hemicellulases, besides acting in the hydrolysis of lignocellulosic materials, have a versatile use in industrial sectors, such as in food, beverages and biofuels. The main aims of this thesis were the design of efficient strategies for the production of enzymes and enzymatic cocktails for use in plant biomass hydrolysis and the application of immobilization techniques to increase the use of enzymes in a commercial scale. Initially, bioprospection of new enzyme secreting microorganisms active in lignocellulosic biomass was performed, and among the eighty Streptomyces strains tested, two strains (F1 and F7) were distinguished by their high cellulolytic and hemicellulolytic activities. A genomic approach of these strains allowed the identification of 85 glycoside hydrolases (GHs) distributed in 33 different families the strain F1, and 100 GHs arranged in 44 families the strain F7. In addition, the genomic data from strains F1 and F7 also indicated the presence of genes related to lignin degradation. Statistical tools were also applied and allowed the increase in GH production by strain F1. With the optimization, high concentrations of GHs were achieved with a nutrient medium containing 16.4 g L-1 of wheat bran and 10.0 g L-1 of casein, where 9.27 U mL-1 of xylanase and 0.22 U mL-1 of cellulase were obtained. To confirm the diversity of GHs expressed by the strain F1, an analysis using mass spectrometry technique was performed and it was observed that the greater the complexity of the carbon source used, the greater the range of proteins secreted, including several types of cellulases and hemicellulases. The efficiency of the enzymatic extract produced with strain F1 was studied for the saccharification of plant biomass and allowed a significant increase in sugar release when added to the commercial cellulolytic extract, indicating that the enzymes expressed by Streptomyces sp. F1 can be applied for the improvement of the current commercial cocktails. The creation of enzyme immobilization methods under neutral conditions of pH was also study. The new agarose supports were used for the immobilization of monomeric and multimeric enzymes of great industrial and biotechnological importance. A more detailed study exploring the new supports and the use of post-immobilization techniques with polymers and small molecules was also proposed. The process developed by applying the polymer polyethyleneimine (PEI) enabled the formation of an excellent system to stabilize the glucose-tolerant tetrameric ?-glycosidase obtained from Exiguobacterium antarcticum. The immobilized ?-glycosidase showed an improvement in its characteristics, with an increased activity, including thermal and storage stability. In addition, the ?-glycosidase maintained a high activity even after several cycles of hydrolysis applying cellobiose as substrateDoutoradoCiência de AlimentosDoutor em Ciência de Alimentos140610/2014-6CNP

A revised bird checklist for the oceanic islands of the Gulf of Guinea (Príncipe, São Tomé and Annobón)

We present an updated bird checklist for the oceanic islands of the Gulf of Guinea. Their avifauna comprises 146 confirmed species, an increase of 19% in 15 years. Of these, 66 are resident landbird species (32 on Príncipe, 50 on São Tomé and 11 on Annobón), including 29 endemic species, 17 endemic subspecies and 17 possibly non-native species. The remaining avifauna consists of six breeding seabird species, four non-breeding migrants, 62 vagrants and eight species of uncertain status. An additional 51 species have been reported but lack confirmation. Most recent changes reflect increases in observer activity and involve vagrant and unconfirmed species, but a few result from previously overlooked historical records and taxonomic changes. Of the three islands, most changes affected the avifauna of Príncipe, whereas little new information has come from Annobón. Future changes are predicted to arise from new reports and confirmation of vagrants, but also from further taxonomic revision of residents.info:eu-repo/semantics/publishedVersio

Fungicide baseline for mycelial sensitivity of Exserohilum turcicum, causal agent of northern corn leaf blight

Northern corn leaf blight, caused by Exserohilum turcicum (Et), is one of the major corn diseases which can reduce grain yield and quality. The aim of this study was to determine the mycelial sensitivity of ten Et isolates, five from Argentina and five from Brazil, to six fungicides (carbendazim, captan, fludioxinil, metalaxyl, iprodione and thiram) used in seed treatment. The inhibitory concentration (IC50) was determined by using seven concentrations of the fungicides supplemented to the agar medium. The mycelial colony diameter was measured with a digital caliper. Experimental design was completely randomized with four replicates. Data on the percent mycelial growth inhibition were analyzed by logarithmic regression and the IC50 was calculated. The fungicide iprodione was the most potent, with IC50 < 0.01 mg/L, followed by fludioxonil, IC50 0.31 mg/L, and thiram, 1.37 mg/L. Carbendazim, metalaxyl and captan were classified as non-fungitoxic, showing IC50 > 50 mg/L for all isolates. Although iprodione is the most potent fungicide, it is not used for corn seed treatment. The IC50s obtained in this study can be used as baseline for future monitoring studies of Et sensitivity to fungicides.Fil: De Rossi, Roberto Luis. Universidad Católica de Córdoba. Facultad de Ciencias Agropecuarias; Argentin

Using robust portfolios techniques in emerging markets

Financial data are heavy tailed containing some proportion of extreme observations. We propose to use a robust covariance estimator to define the center and orientation of the data. We provide an illustration of the usefulness of the proposed procedure to efficiently allocate among emerging stock markets. We show that the resulting robust portfolios may yield higher cumulative returns and have more stable weights. We strongly recommend that a robust covariance matrix is used to solve emerging stock markets allocation problems. We believe that our technique has a key advantage. Because all we change is the covariance matrix, we can use any commercially available optimizer to obtain robust portfolio weights.Indisponível

Maximum drawdown: models and applications

Financial series may possess fractal dimensions which would induce cycles of many different durations. This inherent characteristic would explain the turbulent cascades in stock markets when strong local dependence is observed. A drawdown is defined as the percentual accumulated loss due to a sequence of drops in the price of an investment. It is collected over non-fixed time intervals and its duration is also a random variable. The maximum drawdown occuring during a fixed investment horizon is a flexible measure that may provide a different perception of the risk and price flow of an investment. In this paper we propose statistical models from the extreme value theory for the severity and duration of the maximum drawdown. Our empirical results indicate that there may exist a relation between the pattern of the GARCH volatility of an investment and the fluctuations of the severity of the maximum drawdown and that, typically, extreme (but not outlying) maximum drawdowns occur during stress periods of high volatility. We suggest applications for the maximum drawdown, including the computation of the Maximum Drawdown-at-Risk with exceedance probability α, and the classification of investments according to their performance when controlling losses via the maximum drawdown.Indisponível

El Niño Oscilação Sul e o acúmulo de horas de frio para a superação da dormência em fruteiras de clima temperado no sul do Brasil

The number of chilling hours is responsible for maximizing budding and flowering in temperate climate fruit trees, and this number varies widely between years. An important source of variability is the occurrence of the ENSO - El Niño Southern Oscillation. With the intent of further understanding, the objective set was to analyze the influence of ENSO on chilling hours in Rio Grande do Sul State. To perform the analysis it was used data of air temperature - below 7.2 o C - from 24 meteorological stations. The results showed that when La Niña occurs, the percentage of chilling hours was above average for the period analyzed in all locations, and when El Niño occurs, the values were below average in 79% of the locations. The highest number of chilling hours, observed in each location, mainly occurred during the presence of La Niña and the lowest number was mainly observed during the occurrence of El Niño. The largest deviation (%) of chilling hours from the average occurred in May. Despite the month of July having the highest number of chilling hours, the occurrence of El Niño or La Niña does not show any difference between them. The month of September also shows no difference when comparing instances of El Niño and La Niña.O número de horas de frio é responsável pela maximização da brotação e floração em fruteiras de clima temperado, e esse número varia muito entre os anos. Uma importante fonte de variabilidade é a ocorrência do ENOS - El Niño Oscilação Sul. Com intuito de um melhor entendimento, objetivou-se analisar a influência do fenômeno El Niño Oscilação Sul, sobre o acúmulo de horas de frio no estado do Rio Grande do Sul. Para isso, utilizou-se dados de temperatura do ar, abaixo de 7,2 o C, de 24 estações meteorológicas. Os resultados mostraram que, quando da ocorrência de La Niña, o percentual de horas de frio foi superior à média em todas as localidades e durante o El Niño os valores ficaram abaixo da média em 79% das localidades. O maior número de horas de frio, observado em cada localidade ocorreu, predominantemente, durante a La Niña e, o menor número foi observado, predominantemente, durante a ocorrência de El Niño. O maior desvio (%) de horas de frio em relação à média ocorreu no mês de maio. Apesar do mês de julho ter o maior número de horas de frio, a ocorrência do El Niño ou La Niña não apresenta diferença entre si. O mês de setembro também não apresenta diferença na comparação entre os eventos de El Niño e La Niña