Structural bioinformatics study of PNP from Schistosoma mansoni

The parasite Schistosoma mansoni lacks the de novo pathway for purine biosynthesis and depends on salvage pathways for its purine requirements. Schistosomiasis is endemic in 76 countries and territories and amongst the parasitic diseases ranks second after malaria in terms of social and economic impact and public health importance. The PNP is an attractive target for drug design and it has been submitted to extensive structure-based design. The atomic coordinates of the complex of human PNP with inosine were used as template for starting the modeling of PNP from S. mansoni complexed with inosine. Here we describe the model for the complex SmPNP-inosine and correlate the structure with differences in the affinity for inosine presented by human and S. mansoni PNPs. (C) 2004 Elsevier B.V. All rights reserved.

Pitiose em animais de produção no Pantanal Matogrossense

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estimativa da probabilidade do evento extremo de precipitação de janeiro de 2000 no Vale do Paraíba, baseada na distribuição generalizada de pareto

Um evento extremo de precipitação ocorreu na primeira semana do ano 2000, de 1º a 5 de janeiro, no Vale do Paraíba, parte leste do Estado de São Paulo, Brasil, causando enorme impacto socioeconômico, com mortes e destruição. Este trabalho estudou este evento em 10 estações meteorológicas selecionadas que foram consideradas como aquelas tendo dados mais homogêneos do Que outras estações na região. O modelo de distribuição generalizada de Pareto (DGP) para valores extremos de precipitação de 5 dias foi desenvolvido, individualmente para cada uma dessas estações. Na modelagem da DGP, foi adotada abordagem não-estacionaria considerando o ciclo anual e tendência de longo prazo como co-variaveis. Uma conclusão desta investigação é que as quantidades de precipitação acumulada durante os 5 dias do evento estudado podem ser classificadas como extremamente raras para a região, com probabilidade de ocorrência menor do que 1% para maioria das estações, e menor do que 0,1% em três estações.

Force-versus-time curves during collisions between two identical steel balls

We describe a numerical procedure for plotting the force-versus-time curves in elastic collisions between identical conducting balls. A system of parametric equations relating the force and the time to a dimensionless parameter is derived from the assumption of a force compatible with Hertz's theory of collision. A simple experimental arrangement consisting of a mechanical system of colliding balls and an electrical circuit containing a crystal oscillator and an electronic counter is used to measure the collision time as a function of the energy of impact. From the data we can determine the relevant parameters. The calculated results agree very well with the expected values and are consistent with the assumption that the collisions are elastic. (C) 2006 American Association of Physics Teachers.

Consórcio de espécies nativas da floresta estacional semidecidual com mandioca (Manihot sculenta Crantz) para restauração de mata ciliar

Intercropping of trees and annual crops could be an important alternative for promoting forest restoration in small farms. The objective of this study was to evaluate the intercropping of cassava (Manihot sculenta Crantz) with native trees for restoration of natural forest in riparian areas in the western São Paulo State, Brazil. The experimental design was randomized blocks with six replications for comparing two restoration systems: pure afforestation and afforestation intercropped with cassava. It was evaluated the variables related to seedling development (height, crown diameter, crown cover, and height/crown diameter ratio), mortality and the economic impact were assessed for using cassava. No differences were found between treatments for any dendrometrical variable and mortality. Economic impact of the intercroppoing treatment was positive because costs for establishment of intercropped system were partially reduced by the income from the cassava crop, which covered 32% of total costs. Cassava income made final costs 19% lesser than restoration in the pure afforestation system.

Swarming and incipient colonies of Coptotermes havilandi (Isoptera, Rhinotermitidae)

Coptotermes havilandi Holmgren is an oriental species introduced into Brazil. Despite its economic impact as structural pest, very little is known about the biology of this termite. This paper describes observations of C. havilandi swarming in the city of Rio Claro (SP, Brazil), and reports the first data on incipient colonies reared in a laboratory in Brazil. The preoviposition period lasted about a week after pairing; oviposition began in most of the incipient colonies during the second week. Antennal mutilation occurred on all reproductives. The mean number of the first batch of eggs was 13. In general, first instar brood hatched 60-70 days after set up of the colonies. After two years of pairing there was a small population (less than 100 individuals) and limited soldier production (n=2) in incipient colonies of C. havilandi.

Preliminary studies on agonistic behavior between colonies of Coptotermes havilandi (Isoptera, Rhinotermitidae) in laboratory bioassays

Intercolonial aggression is being used to delimit foraging territory in termite species of subterranean termites. The advance of the introduced pest termite Coptotermes havilandi Holmgren in the interior of São Paulo State is increasing its economic impact as well as its interspecific and intraspecific competition in Brazil. In order to evaluate the intraspecific agonism among different colonies collected in urban areas of Sȧo Paulo State were set up a series of preliminary bioassays. Different combination of nestmates from field colonies of C. havilandi of Rio Claro city showed lack of agonistic behavior. Nevertheless, encounters among individuals from São Paulo and Rio Claro cities showed agonistic behaviors. These preliminary results suggest that caution should be taken in using intercolonial aggression to delimit the foraging territory of C. havilandi colonies in São Paulo State.

Thermoeconomic analysis of a cogeneration system of a university campus

In this paper, a thermoeconomic analysis method based on the First and the Second Law of Thermodynamics and applied to analyse the replacement of an equipment of a cogeneration system is presented. The cogeneration system consists of a gas turbine linked to a waste boiler. The electrical demand of the campus is approximately 9 MW but the cogen system generates approximately one third of the university requirement as well as 1.764 kg/s of saturated steam (at 0.861 MPa), approximately, from a single fuel source. The energy-economic study showed that the best system, based on pay-back period and based on the maximum savings (in 10 years), was the system that used the gas turbine M1T-06 of Kawasaki Heavy Industries and the system that used the gas turbine CCS7 of Hitachi Zosen, respectively. The exergy-economic study showed that the best system, which has the lowest EMC, was the system that used the gas turbine ASE50 of Allied Signal. © 2002 Elsevier Science Ltd. All rights reserved.

Innovaciones en la gestión y calidad de los revestimientos refractarios en la Compañía Sideŕurgica Nacional (Brasil)

The work describes actions carried out in colaboration among the National Steel Company - (CSN)-Brazil and the Interdisciplinary Laboratory of Electrochemistry and Ceramic - LIEC of the Federal University of Sao Carlos Brazil (UFSCar-Brazil), in the area of I&D, for integral management and improvement of the quality and performance of the refractory linings in the sintering areas, blast furnace, hot air pipe lines transferency to the blast furnace, pig-iron ladles, running channels, blast furnaces hearths, torpedo car, etc., as well as, the economic impact generated by the installation of the adopted measures.

Care arrangements for people with dementia in developing countries

Background: Rapid demographic ageing will soon lead to large increases in the numbers of persons with dementia in developing countries. This study is the first comprehensive assessment of care arrangements for people with dementia in those regions. Methods: A descriptive and comparative study of dementia care; caregiver characteristics, the nature of care provided, and the practical, psychological (Zarit Burden Interview, General Health Questionnaire) and economic impact upon the caregiver in 24 centres in India, China and South East Asia, Latin America and the Caribbean and Africa. Results: We interviewed 706 persons with dementia, and their caregivers. Most caregivers were women, living with the person with dementia in extended family households. One-quarter to one-half of households included a child. Larger households were associated with lower caregiver strain, where the caregiver was co-resident. However, despite the traditional apparatus of family care, levels of caregiver strain were at least as high as in the developed world. Many had cutback on work to care and faced the additional expense of paid carers and health services. Families from the poorest countries were particularly likely to have used expensive private medical services, and to be spending more than 10% of the per capita GNP on health care. Conclusions: Older people in developing countries are indivisible from their younger family members. The high levels of family strain identified in this study feed into the cycle of disadvantage and should thus be a concern for policymakers in the developing world. Copyright © 2004 John Wiley & Sons, Ltd.

Transforming open mining pits into fish farms: Moving towards sustainability

The legacy of mining activities has typically been land 'returned to wildlife', or, at some sites, degraded to such an extent that it is unsuitable for any alternate use. Progress towards sustainability is made when value is added in terms of the ecological, social and economic well-being of the community. In keeping with the principles of sustainable development, the innovative use of flooded open pits and tailings impoundments as commercial, recreational or ornamental fish farms should be considered in some locations, as it could make a significant contribution to the social equity, economic vitality and environmental integrity of mining communities. This article highlights the growing significance of aquaculture and explores the benefits and barriers to transforming flooded pits and impoundments into aquaculture operations. Among other benefits, aquaculture may provide a much-needed source of revenue, employment and, in some cases, food to communities impacted by mine closure. Further, aquaculture in a controlled closed environment may be more acceptable to critics of fish farming who are concerned about fish escapes and viral transmissions to wild populations. Despite the potential benefits, aquaculture in flooded pits and impoundments is not without its complications - it requires a site-specific design approach that must consider issues ranging from metals uptake by fish, to the long-term viability of the aquatic system as fish habitat, to the overall contribution of aquaculture to sustainability. © 2004 United Nations. Published by Blackwell Publishing.

Evaluation of integrated inverter topologies for low power PV systems

This work presents the stage integration in power electronics converters as a suitable solution for solar photovoltaic inverters. The rated voltages available in Photovoltaic (PV) modules have usually low values for applications such as regulated output voltages in stand-alone or grid-connected configurations. In these cases, a boost stage or a transformer will be necessary. Transformers have low efficiencies, heavy weights and have been used only when galvanic isolation is mandatory. Furthermore, high-frequency transformers increase the converter complexity. Therefore, the most usual topologies use a boost stage and one inverter stage cascaded. However, the complexity, size, weight, cost and lifetime might be improved considering the integration of both stages. These are the expected features to turn attractive this kind of integrated structures. Therefore, some integrated converters are analyzed and compared in this paper in order to support future evaluations and trends for low power single-phase inverters for PV systems. © 2011 IEEE.

Comparative analysis of MPPT techniques for PV applications

This paper presents a careful evaluation among the most usual MPPT techniques, doing meaningful comparisons with respect to the amount of energy extracted from the photovoltaic (PV) panel, PV voltage ripple, dynamic response and use of sensors, considering that the models are first implemented via MatLab/Simulink®, and after a digitally controlled boost DC-DC converter was implemented and connected to an Agilent Solar Array simulator in order to verify the simulation results. The prototype was built, the algorithms are digitally developed and the main experimental results are also presented, including dynamic responses and the experimental tracking factor (TF) for the analyzed MPPT techniques. © 2011 IEEE.

Detection of post-F1 fish hybrids in broodstock using molecular markers: Approaches for genetic management in aquaculture

Herein, we have developed molecular markers for nuclear genes to use in multiplex-PCR and PCR-RFLP, with the goal of characterising hybrid lines derived from crosses between pintado Pseudoplatystoma corruscans and cachara P. reticulatum. These markers, together with others described previously, were used to perform molecular identification analyses as genetic subsidies for Brazilian aquaculture. These analyses were performed due to the problems of high mortality in the offspring reported by the aquaculturist. From a total of 16 broodstock samples, 13 were genetically identified as hybrids; surprisingly, nine of these hybrids were found to be post-F1 lineages. These data show that the fertility of these animals can seriously affect the cultivated stocks, thus causing financial damage in this aquaculture system. The establishment of PCR-RFLP and multiplex-PCR as molecular techniques allows for both the correct management of these animals and the routine monitoring of production and trade of fish hybrids in aquaculture. Consequently, such tools will enable a sustainable development in the aquaculture industry. © 2012 Blackwell Publishing Ltd.

Three-phase tri-state buck-boost integrated inverter

This paper presents a three-phase integrated inverter suitable for stand-alone and/or grid-connected applications. The usage of the special features of the tri-state coupled with the special space vector modulation allows the inverter to present an attractive degree of freedom for the controllers' design, i.e. input and output can be controlled independently. Additionally all controllers are based on dq0 transformation, the system are described and interesting simulation results are available to confirm the proposal. Finally, this paper presents experimental evaluations of the inverter feeding a three-phase stand-alone load confirming the remarkable features of the decoupling control. © 2013 IEEE.