Uma análise da alocação de contratos futuros sobre commodities em portfólios diversificados

O trabalho analisou o impacto da introdução dos contratos futuros agropecuários (de café arábica, soja, milho, açúcar cristal, etanol e boi gordo), negociados na Bolsa de Valores, Mercadorias e Futuros - BM&FBovespa, no risco e no retorno de uma carteira diversificada, composta por ações, títulos, ouro e dólar, entre agosto de 1994 e dezembro de 2007. Foram realizados estudos para o intervalo de tempo completo e para subdivisões de dois e três períodos, além de uma análise bianual. Foram consideradas quatro diferentes estratégias com tais derivativos: posições compradas e vendidas em contratos de primeiro vencimento e de prazos superiores a seis meses. Com o uso da Teoria do Portfólio, observaram-se expansões da fronteira eficiente na análise bianual e para os períodos 1994-1998 e 1999-2003, porém estas não foram estatisticamente significativas, conforme metodologia de Gibbons, Ross e Shanken (1989).This paper analyzed the impact of including commodity futures (arabica coffee, soybean, corn, crystal sugar, ethanol and fed cattle), negotiated at Securities, Commodity and Futures Exchange (BM&FBovespa), in the performance of a diversified portfolio, composed by stocks, bonds, gold and dollar, between August of 1994 and December of 2007, when were studied the complete time break and subdivisions of two and three periods, adding a biannual analysis. Different strategies with these derivatives were considered: buy and hold or sell and hold contracts of first settlement or that took six months to maturity. Using the Portfolio Theory, results in biannual analysis and over the time periods 1994-1998 and 1999-2003 showed improvement in portfolio efficiency, but without statistical significance, according methodology used by Gibbons, Ross e Shanken (1989)

Transferência de informações em tecnologias apropriadas para pequenos produtores rurais brasileiros

Transfer of information of Appropriate Technology (ART) is neglected by literature of Information Science. State borne concepts and practices of capital reproduction in Brazil appear as obstacles to criation and development of AT transfer systems. Government, while ignoring small agriculture producers technical needs, coerce them into a model alien to pre-capitalistic traditions, disregarding AT fundamental tenets and leading existing AT systems into misconceptions. AT is seen as a rescue board for late inexpensive but necessary technology drive, recognized only by Non-Governamental Organizations, a modestly successful sector. Government is found inadequate to transfer AT to empoverished groups as it miscomprehends major points such as Education as an AT, namely, Participative Action Research (PAR), Latin American originary and apt to cause positive impact in conscientized technification. Suggestions are offered as to organize AT transfer systems considering PAR as a determining factor for obtaining productive results Keywords: Holistic agriculture, Participative Action Research.CAPESTransferência de informações em Tecnologia Apropriada (TA) e negligenciada na literatura de Ciência da Informação. Conceitos e praticas de Estado quanto a reprodução de capital no Brasil obstaculizam a criação e desenvolvimento de sistemas de transferência de TA. O governo enquanto ignora as necessidades tecnológicas dos pequenos agricultores, coage-lhes a um modelo agrícola alheio a suas tradições pré-capitalistas, desconsiderando os princípios fundamentais das TA e levando os sistemas de TA existentes a erros de concepção. As TA são vistas como tábua de salvação para uma tecnificação tardia, barata mas necessária, e reconhecidas como tal pelas Organizações Nao-Governamentais, setor modestamente bem-sucedido. Demonstra-se que setores de governo são inadequados a transferência de informações para os pequenos produtores empobrecidos em razão da incompreensão da TA para a Educação, da Pesquisa-Ação Participativa (PaP) originaria da América Latina e apta a causar efeitos positivos na tecnificação conscientizada. Oferecem-se sugestões para a organização de sistemas de transferência de informações de TA que considerem a PaP como fator determinante para a obtenção de resultados produtivos

A System Dynamics Approach To Logistics Outsourcing Policies And Decisions

This paper is based on a revelatory single-case study that uses a system dynamics model to analyze the costs and policies of a distribution logistics outsourcing process (i.e., the warehousing and transportation activities) of a Brazilian consumer packaged goods (CPG) company. The model considers the costs before and after the outsourced operation startup and how these costs influence the net present value (NPV) of the process. The model’s findings suggest policies, such as the reduction of the ex-ante period and the ex-ante reactive and proactive monitoring of operations, to obtain optimal financial results. In addition, the model provides guidelines for the contract lengths and demonstrates that in the outsourcing process, the greatest gains result during periods of low inflation and low interest rates in a stable economy.26228530

Threats to the Cerrado remnants of the state of São Paulo, Brazil

Patches of natural vegetation remaining in landscapes occupied by man are continuously under threat due to the edge effects and also to land use types around these remnants. The most frequent threats and land use types in the vicinity of 81 Cerrado (tropical savanna type) fragments in the State of São Paulo, Brazil, were analyzed in order to verify if the frequency of every type of disturbance to the natural ecosystem depends on the neighboring land use. The hypothesis of the study assumes that environmental threats are correlated with land use around protected areas. From the 81 areas, the most frequent human-induced land cover types around the Cerrado remnants were: pasture (recorded in 78% of the areas), sugarcane plantations (26%), roads (19%), annual crops and reforestation (14% each). The most frequent sources of threats were invasive grasses (35% of the areas partially or totally invaded) and cattle (observed in 32% of the areas), followed by deforestation (21%), and fire (21%). The chi-square analysis revealed that, with the exception of deforestation, which does not depend on land use, all other threats are influenced by the neighboring land use. The occurrence of invasive grasses and fires are strongly favored by the presence of roads and urban areas. Sugarcane, reforestation, and permanent crops were the less impacting land use types found in the study area, when only considering impact frequency. These land use types have fire and weed control, and also exclude cattle, indirectly protecting natural ecosystems.Fragmentos remanescentes de vegetação natural em paisagens antropizadas sofrem ameaças permanentes, devido aos efeitos de borda e às atividades antrópicas nas áreas limítrofes. Para verificar a hipótese de que o tipo de ameaça ao ecossistema e a sua freqüência dependem do uso da terra no seu entorno, foram analisados 81 fragmentos de Cerrado no estado de São Paulo. Para cada fragmento foram registrados os tipos de perturbação no ecossistema e os tipos de uso da terra no seu entorno. Os usos mais freqüentes foram pastagens cultivadas (registradas em 78% das áreas), plantio de cana-de-açúcar (26%), rodovias (19%), reflorestamento (14%) e culturas anuais (14%). As ameaças mais freqüentemente registradas foram gramíneas invasoras (35% das áreas parcial ou totalmente invadidas), presença de gado (32%), desmatamento (21%) e fogo (21%). A análise da freqüência observada de cada tipo de impacto mediante a freqüência esperada caso não houvesse influência do uso da terra (qui-quadrado), mostrou que as ameaças dependem do uso da terra nas áreas ao redor dos fragmentos, exceto para o desmatamento, que tem ocorrido indiferentemente ao tipo de uso. Gramíneas invasoras e fogo são muito mais freqüentes na vizinhança de rodovias e zonas urbanas, enquanto que o plantio de cana-de-açúcar, silvicultura e fruticultura têm sido os usos da terra menos impactantes para a vegetação de Cerrado, considerando-se apenas a freqüência de ocorrência dos impactos. Esses cultivos envolvem o controle de plantas invasoras e a prevenção e controle de incêndios, e a eliminação do gado, com reflexos positivos para a conservação dos ecossistemas naturais

Dry artificial perches and the seed rain in a subtropical riparian forest

The recovering of forest areas is important for the conservation and maintenance of environments deforested by the agriculture expansion. A low cost alternative of forest restoration is the use of dry artificial perches to increase and qualify the seed rain. The present work aimed at evaluating the effect of the dry artificial perches on the seed rain in an abandoned pasture next to a Seasonal Subtropical Forest remnant in the Ijuí river sub-basin (28°35’25”S, 54°08’09”W), Jóia, Rio Grande do Sul State, Brazil. The seed rain under the dry perches was compared to the seed rain under the forest remnant. The identification of the potentially disperser birds was also carried out. The seed traps were disposed under the forest remnant, under the dry perches and at random in the open area as a control, and the seeds were collected monthly between November 2007 and May 2008. It has been collected 9,395 seeds, distributed in 16 Families. Asteraceae and Poaceae summed 5,990 seeds. The tree species reached the amount of 2,177 (22.6%) pertaining to 15 species. Such value represents 0.76 seeds·m-2·day-1 to the tree species. Under the forest remnant, the seed rain intensity of all tree species and of the zoochoric tree species were 2.59 and 0.40 seeds·m-2·day-1, respectively. In the seed traps under the perches the seed rain intensity was 0.29 seeds·m-2·day-1, and more than 99% of them were of zoochoric tree species. The only one anemochoric species observed in the seed traps of the pasture was Helietta apiculata Bentham, which presented only two seeds in the traps of pasture, indicating a low efficiency of dispersion. The birds observed in the perches pertaining to Thraupinae and Turdinae. A recuperação de áreas florestais é importante para conservação e manutenção de ambientes desflorestados pela expansão agrícola. Uma alternativa de baixo custo para a restauração florestal é a utilização de poleiros secos artificiais para o recrutamento de sementes. O objetivo deste trabalho foi avaliar o efeito dos poleiros secos artificiais sobre a chuva de sementes de espécies arbóreas em uma pastagem abandonada junto a um fragmento de Floresta Estacional na sub-bacia do rio Ijuí (28°35’25”S, 54°08’09”W), em Jóia, Rio Grande do Sul, Brasil. A chuva de sementes sob os poleiros secos foi comparada com a observada sob a floresta remanescente. As aves potencialmente dispersoras foram identificadas. Foram utilizados coletores dispostos sob o remanescente florestal, sob os poleiros secos, e  aleatoriamente na área de estudo como controle. As sementes foram coletadas mensalmente entre novembro de 2007 e maio de 2008. Foram coletadas 9.395 sementes distribuídas em 16 famílias na soma dos três tratamentos. Asteraceae e Poac8relativamente baixa de dispersão. As aves mais freqüentes nos poleiros pertencem à família Thraupinae e à subfamília Turdinae

Futuros agropecuários em portfólios de máxima utilidade esperada

This study investigates the composition of maximum expected utility portfolio, considering stocks, bonds, gold, dollar and agricultural futures contract, between August of 1994 and December of 2007. From the optimal combinations of risk-return (calculated by Markowitz algorithm) and the use of a quadratic utility function (with different levels of risk aversion), were obtained portfolios that maximizes expected utility. The commodity futures were not present in the maximum expected utility portfolios for the complete period, 1994-2000. However, with division of sample in two and three periods, the commodity futures were included in these portfolios during the 2000s. Furthermore, in general, with the risk aversion increase, the participation of these papers in the portfolio had fall.Portfolio, Agricultural futures contract, Utility, Risk and Uncertainty,

A system dynamics approach to logistics outsourcing policies and decisions

This paper is based on a revelatory single-case study that uses a system dynamics model to analyze the costs and policies of a distribution logistics outsourcing process (i.e., the warehousing and transportation activities) of a Brazilian consumer packaged goods (CPG) company. The model considers the costs before and after the outsourced operation startup and how these costs influence the net present value (NPV) of the process. The model’s findings suggest policies, such as the reduction of the ex-ante period and the ex-ante reactive and proactive monitoring of operations, to obtain optimal financial results. In addition, the model provides guidelines for the contract lengths and demonstrates that in the outsourcing process, the greatest gains result during periods of low inflation and low interest rates in a stable economy26228530

Behavioral aspects of Caracu and Red Angus cattle breeds in a pasture with shade and water immersion

The shade is an important resource in the extensive production systems in tropical regions. The aim of this study is to understand through behavioral analysis, the preferences of animals for resources for environmental protection. The experiment was conducted in the Biometeorology and Ethology Laboratory of FZEA-USP. Six male of Caracu and Red Angus cattle breeds were used. The animals were submitted to 2 different treatments: availability of artificial shade and water for immersion and availability of water for immersion. The observations of the behavioral patterns were recorded using the focal sampling method every 15 minutes (12h/day). The observed positions were: in the sun, under the shade and in the water. The posture observed were: standing, lying down and behavioural activities were grazing, ruminating and rest. The data concerning to the time spent in different behaviors and different positions were analyzed by the multifactorial variance (ANOVA-GLM). The fixed factors used were the breed and treatment. The results had shown that grazing activity was the behavior in which both breeds had spending more time (especially in the cooler periods), followed by ruminating in the Caracu and by resting in the Red Angus. The results also had shown that shade can be used as a shelter against solar radiation as well against rain. The Caracu had presented a clear preference for the shade, particularly in the hottest hours. However this was not always observed in Red Angus, who sometimes chose to remain in the water. In hot climates, resources for defense against heat load, as shade and water for immersion can really improve the welfare of the cattle