Asymmetric phase-transfer catalytic sulfanylation of some 2-methylsulfinyl cyclanones. Modeling of the stereochemical course of the aldol reaction of (SS,2S)-2-methylsulfinyl-2-methylsulfanylcyclohexanone

Increased diastereoisomeric excesses are obtained for the sulfanylation reactions of some 2-methylsulfinyl cyclanones under phase-transfer catalysis using the chiral catalyst QUIBEC instead of TEBA. The optically pure (SS,2S)-2-methylsulfinyl-2-methylsulfanylcyclohexanone thus prepared reacts with ethyl acetate lithium enolate affording, after hydrolysis, (R)-2-[(ethoxycarbonyl)methyl]-2-hydroxycyclohexanone in 60% ee. Density functional theory calculations (at the B3LYP/6-311++G(d,p) level) can successfully explain the origin of this result as the kinetically favored axial attack of the nucleophile to the carbonyl group of the most stable conformer of the cyclanone, in which the CH(3)SO and CH(3)S groups are at the equatorial and axial positions, respectively. (C) 2010 Elsevier Ltd. All rights reserved.

Modelling the Provenance of Data in Autonomous Systems

Determining the provenance of data, i.e. the process that led to that data, is vital in many disciplines. For example, in science, the process that produced a given result must be demonstrably rigorous for the result to be deemed reliable. A provenance system supports applications in recording adequate documentation about process executions to answer queries regarding provenance, and provides functionality to perform those queries. Several provenance systems are being developed, but all focus on systems in which the components are textitreactive, for example Web Services that act on the basis of a request, job submission system, etc. This limitation means that questions regarding the motives of autonomous actors, or textitagents, in such systems remain unanswerable in the general case. Such questions include: who was ultimately responsible for a given effect, what was their reason for initiating the process and does the effect of a process match what was intended to occur by those initiating the process? In this paper, we address this limitation by integrating two solutions: a generic, re-usable framework for representing the provenance of data in service-oriented architectures and a model for describing the goal-oriented delegation and engagement of agents in multi-agent systems. Using these solutions, we present algorithms to answer common questions regarding responsibility and success of a process and evaluate the approach with a simulated healthcare example.

Syntheses of Cross-Linking Agents, Molecular Modeling of Oligonucleotides and Polypeptide-Ion Complexes

Each section of this thesis will be subdivided into three parts encompassing all of the research in which I have been involved during the past three years. These will be referred to under the headings "Syntheses:' "Molecular Modeling," and "Cross-linking Efficiencies." Each of these subdivisions may have divisions within them when necessary in order to fully detail the research.

Modeling Of District Metered Areas With Relatively High Leakage Rate. The Case Study Of Kalipoli’s DMA

The article reviews the modelling of District Metered Areas (DMAs) with relatively high leakage rate. As a generally recognised approach in modelling of leakage does not exist, modelling of leakage by enginners and other researchers usually takes place by dividing the whole leakage rate evenly to all available nodes of the model. In this article, a new methodology is proposed to determine the nodal leakage by using a hydraulic model. The proposed methodology takes into consideration the IWA water balance methodology, the Minimum Night Flow (MNF) analysis, the number of connections related to each node and the marerial of pipes. In addition, the model is illustrated by a real case study, as it was applied in Kalipoli’s DMA. Results show that the proposed model gives reliable results.

Country factors and the dynamic modeling of capital structure : an empirical study of latin american firms

Desenvolvemos modelos de ajuste parcial e de duration para testar a relevância de fatores específicos de países na determinação da estrutura de capital de empresas listadas nas bolsas de valores brasileira, chilena e mexicana. Utilizamos dados em painel, em um período que se estende do quarto trimestre de 1996 ao segundo trimestre de 2010, abrangendo 4403 observações relacionadas a 139 empresas diferentes. Os resultados obtidos sugerem que a dinâmica da estrutura de capital varia por país e que idiossincrasias locais são determinantes-chave dos níveis de alavancagem das empresas. Não detectamos comportamento explicado pela Teoria de Trade Off entre as empresas brasileiras, chilenas e mexicanas, o que indica que teorias alternativas possam comandar os processos de decisão de financiamento dos gestores latino americanos.

Factors affecting the technical efficiency of production of the Brazilian banking system : a comparison of four statistical models in the context of data envelopment analysis

This paper uses an output oriented Data Envelopment Analysis (DEA) measure of technical efficiency to assess the technical efficiencies of the Brazilian banking system. Four approaches to estimation are compared in order to assess the significance of factors affecting inefficiency. These are nonparametric Analysis of Covariance, maximum likelihood using a family of exponential distributions, maximum likelihood using a family of truncated normal distributions, and the normal Tobit model. The sole focus of the paper is on a combined measure of output and the data analyzed refers to the year 2001. The factors of interest in the analysis and likely to affect efficiency are bank nature (multiple and commercial), bank type (credit, business, bursary and retail), bank size (large, medium, small and micro), bank control (private and public), bank origin (domestic and foreign), and non-performing loans. The latter is a measure of bank risk. All quantitative variables, including non-performing loans, are measured on a per employee basis. The best fits to the data are provided by the exponential family and the nonparametric Analysis of Covariance. The significance of a factor however varies according to the model fit although it can be said that there is some agreements between the best models. A highly significant association in all models fitted is observed only for nonperforming loans. The nonparametric Analysis of Covariance is more consistent with the inefficiency median responses observed for the qualitative factors. The findings of the analysis reinforce the significant association of the level of bank inefficiency, measured by DEA residuals, with the risk of bank failure.

Information mining and visualization of data from the Brazilian Supreme Court (STF): a case study

EMAp - Escola de Matemática Aplicada

Analysis an development of a prototype based on media wiki and semantic media wiki integrated with a design modeling that allows modeling of organizations based on demo

In a world where organizations are ever more complex the need for the knowledge of the organizational self is a growing necessity. The DEMO methodology sets a goal in achieving the specification of the organizational self capturing the essence of the organization in way independent of its implementation and also coherent, consistent, complete, modular and objective. But having such organization self notion is of little meaning if this notion is not shared by the organization actors. To achieve this goal in a society that has grown attached to technology and where time is of utmost importance, using a tool such as a semantic Wikipedia may be the perfect way of making the information accessible. However, to establish DEMO methodology in such platform there is a need to create bridges between its modeling components and semantic Wikipedia. It’s in that aspect that our thesis focuses, trying to establish and implement, using a study case, the principles of a way of transforming the DEMO methodology diagrams in comprehensive pages on semantic Wikipedia but keeping them as abstract as possible to allow expansibility and generalization to all diagrams without losing any valuable information so that, if that is the wish, those diagrams may be recreated from the semantic pages and make this process a full cycle.

Semiparametric modeling of the spatial distribution of occupational accident risk in the casual labor market, Piracicaba, southeast Brazil

The objective of this study was to estimate the spatial distribution of work accident risk in the informal work market in the urban zone of an industrialized city in southeast Brazil and to examine concomitant effects of age, gender, and type of occupation after controlling for spatial risk variation. The basic methodology adopted was that of a population-based case-control study with particular interest focused on the spatial location of work. Cases were all casual workers in the city suffering work accidents during a one-year period; controls were selected from the source population of casual laborers by systematic random sampling of urban homes. The spatial distribution of work accidents was estimated via a semiparametric generalized additive model with a nonparametric bidimensional spline of the geographical coordinates of cases and controls as the nonlinear spatial component, and including age, gender, and occupation as linear predictive variables in the parametric component. We analyzed 1,918 cases and 2,245 controls between 1/11/2003 and 31/10/2004 in Piracicaba, Brazil. Areas of significantly high and low accident risk were identified in relation to mean risk in the study region (p < 0.01). Work accident risk for informal workers varied significantly in the study area. Significant age, gender, and occupational group effects on accident risk were identified after correcting for this spatial variation. A good understanding of high-risk groups and high-risk regions underpins the formulation of hypotheses concerning accident causality and the development of effective public accident prevention policies.

Purification, characterization, crystallization and theoretical molecular modeling of gyroxin fraction from Crotalus durissus terrificus venom (Laurenti, 1768)

The venom of Crotalus durissus terrificus snakes presents various substances, including a serine protease with thrombin-like activity, called gyroxin, that clots plasmatic fibrinogen and promote the fibrin formation. The aim of this study was to purify and structurally characterize the gyroxin enzyme from Crotalus durissus terrificus venom. For isolation and purification, the following methods were employed: gel filtration on Sephadex G75 column and affinity chromatography on benzamidine Sepharose 6B; 12% SDS-PAGE under reducing conditions; N-terminal sequence analysis; cDNA cloning and expression through RT-PCR and crystallization tests. Theoretical molecular modeling was performed using bioinformatics tools based on comparative analysis of other serine proteases deposited in the NCBI (National Center for Biotechnology Information) database. Protein N-terminal sequencing produced a single chain with a molecular mass of similar to 30 kDa while its full-length cDNA had 714 bp which encoded a mature protein containing 238 amino acids. Crystals were obtained from the solutions 2 and 5 of the Crystal Screen Kit (R), two and one respectively, that reveal the protein constitution of the sample. For multiple sequence alignments of gyroxin-like B2.1 with six other serine proteases obtained from snake venoms (SVSPs), the preservation of cysteine residues and their main structural elements (alpha-helices, beta-barrel and loops) was indicated. The localization of the catalytic triad in His57, Asp102 and Ser198 as well as S1 and S2 specific activity sites in Thr193 and Gli215 amino acids was pointed. The area of recognition and cleavage of fibrinogen in SVSPs for modeling gyroxin B2.1 sequence was located at Arg60, Arg72, Gln75, Arg81, Arg82, Lis85, Glu86 and Lis87 residues. Theoretical modeling of gyroxin fraction generated a classical structure consisting of two alpha-helices, two beta-barrel structures, five disulfide bridges and loops in positions 37, 60, 70, 99, 148, 174 and 218. These results provided information about the functional structure of gyroxin allowing its application in the design of new drugs.

Modeling of weeds interference periods in bean

Objetivou-se com este trabalho determinar o período de convivência anterior à interferência das plantas daninhas (PAI) e o período anterior ao dano no rendimento econômico (PADRE) na cultura do feijão, em diferentes espaçamentos (0,45 e 0,60 m) e densidade de plantas (10 e 15 plantas m-1). Os tratamentos foram constituídos de períodos de convivência entre a cultura e as plantas daninhas (0 a 10, 0 a 20, 0 a 30, 0 a 40, 0 a 50, 0 a 60, 0 a 70 e 0 a 80 dias), mais uma testemunha sem convívio com as plantas daninhas. Adotou-se o delineamento experimental de blocos casualizados, com quatro repetições. Os períodos anteriores à interferência (PAI) da cultura foram de 23, 27, 13 e 19 dias após emergência, e os períodos anteriores ao dano no rendimento econômico (PADRE), de 10, 9, 8 e 8 dias, para os tratamentos com espaçamento de 0,45 m e densidades de semeadura de 10 e 15 plantas m-1 e para aqueles com espaçamento de 0,60 m e densidades de semeadura de 10 e 15 plantas m-1, respectivamente, o que reduziu a produtividade de grãos em 63, 50, 42 e 57%, respectivamente, com a presença das plantas daninhas durante todo o ciclo do feijoeiro.

Effect of oils sources on blood lipid parameters of commercial laying hens

The experiment was carried out to verify if total cholesterol, HDL-cholesterol and triacylglicerol plasma levels are affected when laying hens are fed rations containing different dietary oil sources. One hundred sixty 50 week-old hens, assigned to four treatments with five replicates using 8 hens per replicate were used. The experimental period was of 84 days divided in 3 cycles of 28 days each. In the last day of each cycle, blood samples of 2 hens per replicate were randomly choose and blood samples were collected. on the other hand, blood was also collected at 7 am, 11 am and 3 pm aiming to study the daily changes of these lipids. Blood lipid parameters were not affected by different dietary oil sources (p > 0.05); however, HDL-cholesterol did change during the day, giving evidence that this lipid is indeed involved in the egg yolk formation.