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Search Results: 1 - 10 of 340484 matches for " Eduardo F. L.; "
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Conversion of β-carotene into astaxanthin: Two separate enzymes or a bifunctional hydroxylase-ketolase protein?
Juan F Martín, Eduardo Gudi?a, José L Barredo
Microbial Cell Factories , 2008, DOI: 10.1186/1475-2859-7-3
Abstract: Carotenoids are an important group of natural pigments with specific applications as colorants, feed supplements and nutraceuticals; they are also used for medical, cosmetic and biotechnological purposes. A few of the variety of natural and synthetic carotenoids available have been exploited commercially, including β-carotene, lycopene, astaxanthin, canthaxanthin, lutein and capxanthin [1-4]. Although more than 600 different carotenoids have been described from carotenogenic microorganisms [5], only β-carotene, lycopene and astaxanthin are commercially produced by microbial fermentation. These three compounds have various biological functions such as species-specific coloration, light-harvesting, photo-protection, antioxidant, and hormone precursor [6,7]. Dietary carotenoids have beneficial effects delaying the onset of many diseases such as arteriosclerosis, cataracts, age-related macular degeneration, multiple sclerosis, cardiovascular diseases, and some kinds of cancer [4]. For these reasons the demand and market of carotenoids have grown drastically [8].Astaxanthin (Fig. 1) is a xanthophyll widely used as a pigment in aquaculture. The all-trans isomer is found in nature together with small amounts of 9-cis and 13-cis isomers [9]. Due to its high antioxidant activity, astaxanthin has also health benefits such as cardiovascular disease prevention, immune system boosting, bioactivity against Helicobacter pylori, and cataract prevention. Research on the health benefits of astaxanthin is recent and has mostly been performed in vitro or at the pre-clinical level with humans [10]. Research reports support the conclusion that a daily dose of ~5 mg of astaxanthin is of tremendous importance for health management, by protecting cells and body tissues from the oxidative stress caused by free radicals (singlet oxygen), among other reactive oxidants [11]. Astaxanthin producer companies have conducted several studies to demonstrate the safety of natural astaxanthin derived fr
Cisto ósseo aneurismático orbitário - estudo clínico-patológico: relato de caso
Marback, Eduardo F.;Neves, Murilo;Marback, Roberto L.;
Arquivos Brasileiros de Oftalmologia , 2008, DOI: 10.1590/S0004-27492008000600020
Abstract: aneurysmal bone cyst of the orbit is a rare disease that usually affects young patients and is caused by osseous hemodynamic alterations. we report a case of aneurysmal bone cyst of the orbit, referred to us as a dermoid cyst, discussing its clinical and histopathological aspects.
Heberprot-P-associated metabolic control in patients with diabetic foot ulcers
álvarez,Eduardo; Faget,Orestes L; Orlandi,Neraldo; Torres,Omaida F;
Biotecnolog?-a Aplicada , 2010,
Abstract: diabetes mellitus is a unmet medical need of significant social and economical impact. diabetic foot is a chronic and avoidable complication, and still the source of non-traumatic amputations, with metabolic imbalance, macroand micro-angiopathy, and ulceration or trauma contributing to its development. the introduction of heberprot-p to treat diabetic foot ulcers has been a tremendous advance to reduce the amputation index and disability among patients. however, it is essential to guarantee an optimal and personalized glycemic control for achieving even more favorable results. this can be attained by implementing an intensive therapeutic strategy with multiple doses of insulin since the very first diagnose of the lesion. due to the relevance of this topic for medical practice, here is reviewed how to establish such a therapy, and the goals for glycemic control to achieve a better quality of life when attending diabetic foot ulcer patients.
AsistO: A Qualitative MDP-based Recommender System for Power Plant Operation
Reyes, Alberto;Sucar, L. Enrique;Morales, Eduardo F.;
Computación y Sistemas , 2009,
Abstract: this paper proposes a novel and practical model-based learning approach with iterative refinement for solving continuous (and hybrid) markov decision processes. initially, an approximate model is learned using conventional sampling methods and solved to obtain a policy. iteratively, the approximate model is refined using variance in the utility values as partition criterion. in the learning phase, initial reward and transition functions are obtained by sampling the state-action space. the samples are used to induce a decision tree predicting reward values from which an initial partition of the state space is built. the samples are also used to induce a factored mdp. the state abstraction is then refined by splitting states only where the split is locally important. the main contributions of this paper are the use of sampling to construct an abstraction, and a local refinement process of the state abstraction based on utility variance. the proposed technique was tested in asisto, an intelligent recommender system for power plant operation, where we solved two versions of a complex hybrid continuous-discrete problem. we show how our technique approximates a solution even in cases where standard methods explode computationally.
Avalia??o da propaga??o de sinais de radiofrequência para tecnologia Zigbee em granja de frango de corte
Nunes, Eduardo F.;Cappelli, Nelson L.;Umezu, Claudio K.;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2011, DOI: 10.1590/S1415-43662011000100015
Abstract: this study aimed to conduct an evaluation for the implementation of wireless sensors network (wsn) of tracking and control in a poultry farm. the wireless technology used was zigbee, with the ieee 802.15.4 standard forming the physical layer and link layer. to automate the power measurement a delphi language software was developed and, for the prediction of rf signals, an adjusted model of the shadowing was used. all tests were performed in a commercial broiler farm, in the city of tuiuti in the state of s?o paulo, brazil. the results of this study indicate that zigbee technology is appropriate, from the perspective of signal propagation, to implement wsn in poultry housing.
Vena cava superior izquierda persistente
Eduardo A. Sampó,Sandra Swieszkowski,Guillermo F. López Soutric
Medicina (Buenos Aires) , 2008,
Exploration and Navigation for Mobile Robots With Perceptual Limitations
Leonardo Romero,Eduardo F. Morales,L. Enrique Sucar
International Journal of Advanced Robotic Systems , 2008,
Abstract: To learn a map of an environment a mobile robot has to explore its workspace using its sensors. Sensors are noisy and have perceptual limitations that must be considered while learning a map. This paper considers a mobile robot with sensor perceptual limitations and introduces a new method for exploring and navigating autonomously in indoor environments. To minimize the risk of collisions as well as to not exceed the range of sensors, we introduce the concept of a travel space as a way to associate costs to grid cells of the map, based on distances to obstacles. During exploration the mobile robot minimizes its movements, including rotations, to reach the nearest unexplored region of the environment, using a dynamic programming algorithm. Once the exploration ends, the travel space is used to form a roadmap, a net of safe roads that the mobile robot can use for navigation. These exploration and navigation method are tested using a simulated and a real mobile robot with promising results.
Local Estimation of Copula Based Value-at-Risk
Eduardo F. L. de Melo,Beatriz Vaz de Melo Mendes
Revista Brasileira de Finan?as , 2009,
Abstract: In this paper we propose the local maximum likelihood method for dynamically estimate copula parameters. We study the estimates statistical properties and derive the expression for their asymptotic variance in the case of Gaussian copulas. The local estimates are able to detect temporal changes in the strength of dependence among assets. These dynamics are combined with a GARCH type modeling of each individual asset to estimate the Value- at-Risk. The performance of the proposed estimates is investigated through Monte Carlo simulation experiments. In an application using real data, an out-of-sample test indicated that the new methodology may outperform the constant copula model when it comes to Value-at-Risk estimation.
Teste de condutividade elétrica para sementes de pinh o-manso (Jatropha curcas L.) Electrical conductivity test for physic nut (Jatropha curcas L.)
Roberto F Araujo,Jo?o B Zonta,Eduardo F Araújo,Sérgio M. L Donzeles
IDESIA , 2011,
Abstract: RESUMO Para uma análise mais completa da qualidade de sementes, faz-se necessário complementar as informa es fornecidas pelo teste de germina o com testes de vigor, possibilitando, assim, selecionar os melhores lotes para comercializa o e semeadura. Dentre esses testes, destaca-se o de condutividade elétrica. Para sementes de pinh o-manso (Jatropha curcas L.), n o há informa es referentes à metodologia do teste de condutividade elétrica na literatura. Objetivou-se neste trabalho estabelecer metodologia para o teste de condutividade elétrica em sementes de pinh o-manso, variando-se o número de sementes, a quantidade de água e o período de embebi o. Para tanto, foram utilizados oito lotes de sementes de pinh o-manso, e o teste de condutividade elétrica foi realizado com as seguintes varia es: 15, 25 ou 35 sementes, embebidas em 75 ou 100 mL de água destilada à 25 °C, sendo as leituras realizadas após 3, 6, 9, 12, e 24 horas de embebi o. Para efeito de compara o, foram determinadas a porcentagem de germina o e a porcentagem e índice de velocidade de emergência. Com base nos resultados obtidos e pelos coeficientes de correla o calculados entre os resultados de condutividade elétrica e porcentagem de emergência, verificou-se que as metodologias mais eficientes foram com 15 sementes e 75 mL de água, com leituras após 6 horas, 9 horas e 12 horas e 25 sementes e 75 mL de água, com leituras, também, após 6 horas, 9 horas e 12 horas. Concluiu-se que o teste de condutividade elétrica foi eficiente para diferenciar lotes de pinh o-manso quanto à qualidade fisiológica das sementes. A metodologia mais adequada para a realiza o do teste de condutividade elétrica para sementes de pinh o-manso é a conduzida com o uso de 15 sementes e 75 mL de água, com leitura após 6 horas de embebi o. ABSTRACT In order to have more accurate information of seed quality among different seed lots, it is necessary to supplement the data supplied by the germination test with other tests, making possible the selection of best lots for marketing and seeding establishment and among those tests the electrical conductivity test fits well to that purpose. For physic nut (Jatropha curcas L.), no information about electrical conductivity test methods is available in the literature. Thus, the aim of this research was to establish a standard method for testing the electrical conductivity of physic nut seeds leaking, testing different number of seeds, amount of water and soaking period. So, we used eight lots of physic nut seeds proceeding the electrical conductivity test with the followin
A estrutura a termo de taxas de juros no Brasil: modelos, estima??o e testes
Franklin Jr., Sergio L.;Duarte, Thiago B.;Neves, César R.;Melo, Eduardo F. L.;
Economia Aplicada , 2012, DOI: 10.1590/S1413-80502012000200003
Abstract: in this paper, we propose a methodology for the construction of the risk-free interest rate term structure in brazil, using the svensson model for interpolation and extrapolation of the interest rate curves, and genetic algorithms, in complement to traditional algorithms of nonlinear optimization, for estimation of model parameters. the objective is to contribute to the brazilian insurance market, so that insurance ces can appropriately measure their long-term obligations discounting cash flows in a manner that is consistent and coherent, considering the adoption of international standards of solvency supervision and financial reporting by the superintendência de seguros privados (susep). we present the results found in modeling the term structure of a number of interest rate curves in brazil.
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