Análise da reflectância de resinas compostas diretas submetidas a diferentes protocolos de acabamento

Introdução: Dentre os diversos fatores ópticos presentes na estrutura dental, a translucidez caracteriza-se por influenciar diretamente o aspecto final dos dentes. Além dela, pode-se citar opacidade, matiz, valor e croma como outras dimensões de cor também importantes. A reflectância caracteriza-se por avaliar de forma percentual a quantidade de energia luminosa que reflete de determinado objeto. Objetivo: Avaliar a reflectância de resinas compostas de diferentes sistemas restauradores comercialmente disponíveis submetidos a diferentes protocolos de acabamento, bem como as diferenças encontradas nesse estudo in vitro podem influenciar a escolha do material restaurador indicado em diferentes situações clínicas. Materiais e método: este estudo in vitro teve como amostra (n=10) resinas compostas diretas de esmalte e dentina de quatro sistemas diferentes, que foram confeccionadas em espessura de 2mm com o auxílio de uma matriz de teflon, com 0,5 mm de resina de esmalte sobre 1,5 mm de resina de dentina, a fim de simular o dente humano. Após a confecção, a espessura das resinas compostas foi mensurada com um paquímetro digital Mitutoyo e armazenadas em ambiente protegido de luz até o momento das leituras com o espectrofotômetro CARRY 5000. As amostras foram submetidas a medidas de transmitância em três diferentes momentos (após fotopolimerização com tira de poliester, sem nenhum acabamento/polimento; após fotopolimerização e execução de acabamento/polimento e após fotopolimerização e execução de acabamento/polimento seguido de texturização de superfície. Para a análise da morfologia de superfície, foram confeccionadas 3 amostras adicionais para cada grupo de resina, que foram avaliadas em microscopia eletrônica de varredura. Os resultados obtidos foram submetidos ao teste estatístico Shapiro-Wilk para verificação da normalidade. Na presença de distribuição normal, foram submetidos à Análise de Variância Anova, considerando como fator variável o tipo de protocolo de polimento usado, seguido do teste de Tukey com nível de confiança de 95%.Introduction: Among the various optical factors present in the dental structure, a translucency characterized by directly influencing the final aspect of the teeth. In addition, opacity, hue, value and chroma can be cited as other equally important color dimensions. A reflectance characterized by evaluating a percentage form of the amount of light energy that determines the given object. Objective: Evaluate the reflectance of composite resins from different commercially available restorative systems submitted to different finishing protocols, as well as evaluate how the differences found in this in vitro study may influence the choice of restorative material indicated in different clinical situations. Materials and methods: This in vitro study will have as a sample (n = 10) direct composite resins of enamel and dentin from four different systems, which was made in a thickness of 2mm with the aid of a teflon matrix with 0.5 mm resin of enamel on 1.5 mm of dentin resin, in order to simulate the human tooth. After preparation, the thickness of the composite resins was measured with a Mitutoyo digital caliper and stored in a light-protected environment until readings with the CARRY 5000 spectrophotometer. The samples was submitted to transmittance measurements at three different times (after photopolymerization without no finishing / polishing, after photopolymerization and finishing / polishing execution and after polymerization and finishing / polishing and surface texturing For the surface analysis, 3 additional samples was made for each resin group, which was evaluated in electron microscopy in the presence of normal distribution, was submitted to Shapiro-Wilk for normality verification. In the presence of normal distribution, they were submitted to ANOVA, considering as variable factor the type of polishing protocol used, followed by Tukey test with 95% confidence level

Progreso genético teórico en una población regional de ganado lechero

p.155-163Se simuló el progreso genético para producción de leche que podría obtenerse en una población de ganado lechero sujeta a inseminación artificial. La población simulada constó de 100.000 vacas, con un 30 por ciento bajo control lechero, realizándose la selección de machos en 2 etapas (antecesores y prueba de progenie). La simulación se realizó de acuerdo a la teoría clásica del índice de selección e incluyó una estimación de pérdidas por consanguinidad. Las cantidades de toritos muestreados y de hijas por torito que maximizaron el progreso fueron: 43 y 90, para la población y 22 y 90 para la subpoblación controlada. Cuando se restringió la simulación asumiendo que solamente un 20 por ciento de la subpoblación era servida por toros jóvenes, que por lo menos se utilizaban 4 padres de toros y que se seleccionaban el doble de madres de toros necesarias, las cantidades de toritos y de hijas por torito que maximizan el progreso fue ron 19 y 52 tanto para la población total como para la subpoblación controlada

A dynamic deterministic model to evaluate breeding strategies under mixed inheritance

A dynamic deterministic model is proposed to study the combined use of an identified major gene and performance information for selection of traits expressed in one sex. The model considers simultaneously combined adult selection via within genotype thresholds, mating structures according to major genotypes and preselection of young males. The application given indicates that an optimum combination between performances and genotypic information yields better results, in terms of polygenic means, genotype frequencies and cumulated discounted genetic progress, than classical selection ignoring the genotype information. The greatest advantage of combined selection occurs for rare recessive alleles of large effect on phenotypes (up to +49 % for polygenic gains; +26 % for total genetic gain). Optimum within genotype proportions of selected individuals and mating structures vary with generations thus highlighting the value of a dynamic approach.Un modèle déterministe et dynamique est proposé pour étudier l’utilisation conjointe des performances et des génotypes à un locus majeur pour la sélection des caractères exprimés dans un sexe. Le modèle prévoit la sélection des adultes au-delà de seuils de performances intra-génotype, des accouplements en fonction des génotypes et la présélection de jeunes mâles sur leur génotype. L’application présentée indique que la combinaison optimale des performances et des génotypes permet d’obtenir des meilleurs résultats, en terme de moyennes polygéniques, de fréquences génotypiques et du progrès génétique actualisé et cumulé, que la sélection classique ignorant l’informationgénotypique. Les avantages de la sélection combinée sont plus importants quand l’allèle favorable est rare et récessif, les différences avec la sélection classique pouvant atteindre +49 % en gains polygéniques et +26 % en gain génétique total. Les taux optimaux de sélection intra-génotype et les structures d’accouplement optimales varient au cours des générations, confirmant l’intérêt de l’approche dynamique

Character process model for semen volume in AI rams: evaluation of correlation structures for long and short-term environmental effects

The objective of this study was to build a character process model taking into account serial correlations for the analysis of repeated measurements of semen volume in AI rams. For each ram, measurements were repeated within and across years. Therefore, we considered a model including three environmental effects: the long-term environmental effect, which is a random year* subject effect, the short-term environmental effect, which is a random within year subject* collection effect, and the classical measurement error. We used a four-step approach to build the model. The first step explored graphically the serial correlations. The second step compared four models with different correlation structures for the short-term environmental effect. We selected fixed effects in the third step. In the fourth step, we compared four correlation structures for the long-term environmental effect. The model, which fitted best the data, used a spatial power correlation structure for the short-term environmental effect and a first order autoregressive process for the long-term environmental effect. The heritability estimate was 0.27 (0.04), the within year repeatability decreased from 0.56 to 0.44 and the repeatability across years decreased from 0.43 to 0.37

Culture in University Settings

Este artículo presenta parte de los resultados de una investigación sobre la cultura de loscentros universitarios en nuestro país. Se analizan inicialmente los antecedentes del estudiode la cultura en el ámbito universitario sintetizando las diferentes perspectivas utilizadas enel mundo anglosajón (cultura organizativa, cultura de las disciplinas, perspectiva de la inter-acción, etc.) según algunos de los principales estudiosos (Geertz, 1989; Väalima, 1998; Bechery Keynes, 1991 y 2001; y otros). De los diferentes enfoques teóricos elaborados para el estu-dio de la cultura, en este trabajo se ha adoptado la perspectiva organizativa. A continuación,se describen los aspectos metodológicos de la investigación realizada, que consistió en elestudio de un caso en una universidad pública, la Escuela Universitaria de ArquitecturaTécnica de la Universidad de Sevilla, mediante un diseño mixto que combinó las estrategiasde los estudios etnográficos y de tipo survey,con el propósito de determinar qué tipo de sig-nificados culturales comparten los miembros de la comunidad universitaria de un centro per-teneciente a una universidad pública en relación a tres dimensiones analizadas: la formación que imparte, la investigación que desarrollan sus profesores y el clima social del centro.Considerados los resultados obtenidos es posible afirmar que existe un conjunto de signifi-cados compartidos por la comunidad universitaria (rasgos culturales propios del centro) yotros comunes a cualquier centro universitario de nuestro país, en línea con lo que propug-na la perspectiva organizativa. Sin embargo, la cultura del centro aparece como débilmenteasentada dado que no condiciona la vida de los grupos, en cuanto pueden autoexcluirse desu participación en ella (los alumnos) o participar de forma aleatoria (los profesores) sinconsecuencias apreciables.This paper presents some research findings about cultural traits in university settings,looking for shared meanings that may respond to a specific culture which can be outlined inevery faculty of Spanish universities.A rationale about higher education culture summarizes themain views of university culture analysis, looking into the work of the best-known authors(Geertz, 1988; Väalima, 1998; Becher and Kaynes, 1991 and 2001; and others). The metodologyused begins with the case study based of a state university: the school of Technical Architecture,University of Seville. A mixed ethnographic and survey-based approach has been adopted asresearch methodology, collecting and analysing lecturers', students' and clerical staff's sharedmeanings concernig three key elements of school life: the teaching, the research carried outby lectures, and the social environment of the institution. The research outcomes refer to particular traits of the organizational culture of this specific school and to other cultural elements commonly widespread in all university settings. However, there are also otherimportant findings suggesting that the organizational culture of this specific school is weaklyrooted: some community groups are able to exclude themselves from school life (the students), or decide to participate only randomly (the lectures), all of that without any further consequences

Genetic and environmental effects on semen traits in Lacaune and Manech tête rousse AI rams (Open Access publication)

Data from 51 107 and 11 839 ejaculates collected on rams of the "Lacaune" and "Manech tête rousse" breeds, respectively, were analysed to determine environmental and genetic factors affecting semen production traits (ejaculate volume, semen concentration, number of spermatozoa and motility) in young (≤1 year) and adult (≥2 years) rams. Fixed effects and variance components were estimated using multiple trait animal models within each breed. For all traits, the main environmental effects identified were year, season, number of ejaculations, daily variation, interval from previous to current collection and age. Heritability estimates were moderate for volume, concentration and number of spermatozoa (0.12 to 0.33) and lower for motility (0.02 to 0.14). Genetic correlations between ages differed from 1 for all traits (0.14 to 0.90), indicating that semen characteristics corresponded to different traits in young and adult rams. Genetic and phenotypic correlations among traits within age category were globally similar for the different breeds and categories of animals