Influence of sire and sire breed (Gyr versus Holstein) on establishment of pregnancy and embryonic loss in lactating Holstein cows during summer heat stress

Heat stress has negative effects on pregnancy rates of lactating dairy cattle. There are genetic differences in tolerance to heat stress; Bos taurus indicus (B. t. indicus) cattle and embryos are more thermotolerant than Bos taurus taurus (B. t. taurus). In the present study, the effects of sire and sire breed on conception and embryonic/fetal loss rates of lactating Holstein cows during the Brazilian summer were determined. In Experiment 1, cows (n = 302) were AI after estrus detection or at a fixed-time with semen from one Gyr (B. t. indicus) or one Holstein sire (B. t. taurus). Pregnancy was diagnosed 80 days after AI. In Experiment 2, cows (n = 811) were AI with semen from three Gyr and two Holstein sires. Pregnancy was diagnosed at 30-40 and at 60-80 days after AI. Cows diagnosed pregnant at the first examination but non-pregnant at the second were considered as having lost their embryo or fetus. Data were analyzed by logistic regression. The model considered the effect of sire within breed, sire breed, days postpartum, period of lactation, and AI type (AI after estrus versus fixed-time). There was no effect of the AI type, days postpartum or milk production on conception or embryonic loss rates. The use of Gyr bulls increased pregnancy rate when compared to Holstein bulls [9.1% (60/657) versus 5.0% (23/456), respectively, P = 0.008; data from Experiments 1 and 2 combined]. Additionally, in Experiment 2, cows inseminated using semen from sire #4 (Gyr) had lower embryonic loss (10%) when compared with other B. t. indicus (35.3% and 40%) or B. t. taurus sires (18.2% and 38.5%, P = 0.03). In conclusion, the use of B. t. indicus sires may result in higher conception rates in lactating Holstein cows during summer heat stress. Moreover, sire can affect embryonic loss and selection of bulls according to this criterion may result in higher parturition rates in lactating Holstein cows. (c) 2006 Elsevier B.V. All rights reserved.

O estranho testamento de um vigário de província: as memórias de Jean Meslier

En 1762, Voltaire publie un petit livre intitulé Extraits des sentiments de Jean Meslier. Il s'agit d'um abregé des Mémoires de Jean Meslier qui circulaient comme littérature clandestine dans la première moitié du XVIIIe, siècle, sous forme de copies manuscrites. L'interêt de Voltaire pour ces Mémoires est compréhensible. Elles dénoncent toute religion comme imposture et fausseté et annoncent une philosophie matérialiste et athéiste. Quel rôle cet obscur vicaire de province aura exercé dans la constitution de la philosophie des lumières?

Ética em Jean Burlamaqui e o ensino conimbricense do direito natural

Apresentamos o tratado de direito natural Jean Burlamaqui, utilizado nos seminários e ensino de filosofia em Portugal, por volta de 1770. Nosso texto expõe as principais noções morais de sua teoria jusnaturalista, com objetivo de destacar como ela ajudou a configurar então os pressupostos para a reflexão política portuguesa.

Effects of sire breed-grazing system and environmental parameters on the behaviour of beef calves just after birth

Effects of sire breed-grazing system and environmental factors on the first activities of high grade Nellore and crossbred Canchim x Nellore, Angus x Nellore, and Simmental x Nellore calves raised in intensive production systems and high grade Nellore calves raised in an extensive production system, after birth, were studied. During 2 years, 185 calves were observed from birth until the end of first suckling, and the following variables were estimated: duration of maternal attention (cow to calf) during the first 15 min after calving, latency to first attempt to stand up, latency to stand up, latency to first suckling, duration of first suckling and the interval from standing to suckling. Data were analyzed by least squares methods, with models that included fixed effects of year and time of the year of birth (March-April (early autumn) and May-June (late autumn)), sire breed-grazing system (Sy), sex of calf (Se), category of cow (primiparous and pluriparous), time of birth, Sy x Se, year x Sy and year x time of the year interactions and the covariates weight of calf, rainfall, air temperature and relative humidity in the day of birth. Calves born from 6:00 to 8:00 h presented the longest latencies to first stand up (40.3 +/- 5.1 min) and the shortest occur from 14:00 to 16:00 h (15.8 +/- 2.7 min) (P < 0.01). Primiparous cows provided longer attention toward the calf in the first 15 min after birth than pluriparous cows (13.0 +/- 0.7 min versus 11.1 +/- 0.5 min; P < 0.05). This attention was also shorter in earlier autumn (11.0 +/- 0.5 min) and longer in late autumn (13.1 +/- 0.8 min) (P < 0.05). Relative to sire breed-grazing system, Nellore calves raised intensively did take longer to stand and to suckle after birth as compared to crossbred calves also raised intensively (P < 0.01). However, grazing system did not affect (P > 0.05) any behaviour variable studied. As regard to sex differences, female calves did take less (P < 0.01) time to suckle after standing than male calves. Results showed that even purebred or crossbred Bos indicus calves in subtropical environmental need extra care when born on rainy days, especially during the first hours of the day. (C) 2006 Elsevier B.V. All rights reserved.

Influence of sire breed (Bos indicus versus Bos taurus) and interval from slaughter to oocyte aspiration on heat stress tolerance of in vitro-produced bovine embryos

Based on in vitro experiments, Bos indicus embryos were more resistant to heat stress (HS) than Bos taurus embryos. To increase knowledge regarding differences between Bos indicus and Bos taurus in resistance to HS, the primary objective of this study was to determine if tolerance to HS is due to the breed, origin of the oocyte, sperm, or both. Additionally, the influence of the interval between ovary acquisition (in the abattoir) and oocyte aspiration in the laboratory, on early embryo development was ascertained. Oocytes were collected from Nelore and Holstein cows in an abattoir; 4.0 or 6.5 h later, oocytes were aspired in the laboratory, and then matured and fertilized using semen from Nelore (N), Gir (GIR), or Holstein (H) bulls. Ninety-six h post insemination (hpi), embryos with >= 16 cells were divided in two groups: control and HS. In the control group, embryos were cultured at 39 degrees C, whereas in the HS group, embryos were subjected to 41 degrees C for 12 h, and then returned to 39 degrees C. Rates of cleavage, and formation of morula and blastocysts were higher (P < 0.05) for oocytes aspirated at 4.0 versus 6.5 h after ovaries were acquired. Heat stress decreased rates of blastocyst formation for all breeds (N X N; H x H; and H X GIR) and in both time intervals (4.0 and 6.5 h). However, N X N had higher cleavage rate (P < 0.05) in both time intervals when compared with H X H and H X GIR. In addition, Nelore oocytes fertilized with Nelore semen (N X N) had higher blastocyst yields (P < 0.05) in the control and HS group, when compared with the other two breeds (H X H and H X GIR). We concluded that the breed of origin of the oocyte was more important than that of the sperm for development of thermotolerance, because bull breed did not influence embryo development after HS, and in vitro early embryonic development was impaired by increasing (from 4 to 6.5 h) the interval between ovary acquisition and oocyte aspiration. (C) 2011 Elsevier B.V. All rights reserved.

As relações sociais para Jean Piaget: implicações para a educação escolar

Pós-graduação em Educação Escolar - FCLAR

A arte de educar entre a mimese e o sublime: considerações a partir de Theodor W. Adorno e Jean François Lyotard

Pós-graduação em Educação - FFC

As posições políticas de Jean-Paul Sartre e o Terceiro Mundo (1947-1979)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

O pop rock e a escritura poética em Voyages de l’Autre Côté, de Jean-Marie Gustave Le Clezio

A literatura contemporânea expressa o rompimento das fronteiras entre a cultura erudita e a cultura de massa ou comercial, criando formas híbridas que convivem no interior do texto. No romance Voyages de l’autre cote (1975), de Jean-Marie Gustave Le Clézio, as canções do pop rock embalam as viagens da fada Naja Naja e de seus amigos em busca do ‘outro lado’. Desta forma, a impregnação da música popular à escritura poética, parece ajudar a libertar a imaginação, preparando as personagens para o encontro do infinito sensível.

Jean de La Taille e Gil Vicente: dois casos de paratexto imagético

Propor à leitura dois paratextos imagéticos: o retrato de Jean de La Taille, composto de um medalhão oval que contém um epigrama, e a imagem in absentia de Gil Vicente, que se apresenta sob a forma de um enquadramento retangular do qual participam motivos ornamentais e igualmente um epigrama. A leitura destas imagens autorais apresenta a hipótese de uma representação visual, ou mesmo icônica, da atitude literária de dois dramaturgos que se apresentam ao leitor, ao mesmo tempo em que se presentificam, a fim de indicar a maneira mais conveniente de se aproximar da obra - processo essencialmente retórico conhecido sob a apelação de captatio benevolentiae. Palavras-chave: Retrato; paratexto; imagem; representação; interpelação; persuasão; figuração.

Andromaque, de Jean Racine: duas leituras

Este artigo tem o objetivo de apresentar uma obra-prima do teatro clássico francês: Andromaque (1667), de Jean Racine. Primeiramente, efetuamos sua leitura segundo os princípios da doutrina clássica, que se formou entre 1620 e 1660, na França. Nessa perspectiva, Andrômaca, rainha troiana vencida e cativa, é a personagem triunfante, uma forte personalidade feminina fora do alcance do leitor/espectador: quem é de fato Andrômaca, enquanto Pirro não está morto? Em seguida, destacamos uma das análises realizadas pela crítica literária do século XX, a qual utilizou instrumentos interpretativos vários. A leitura que fez Roland Barthes (1963) em Sur Racine subverte a interpretação anterior que se fazia à luz da doutrina clássica, apresentando-nos Pirro como o grande herói trágico, e a personagem mais emancipada do teatro raciniano.

Função simbólica e desenvolvimento da noção temporal em surdos e ouvintes: análise na perspectiva de Jean Piaget

In a previous research, it was observed that are symbolic exchanges established between the persons and the environment they live in that allow them to interact with others, leading them to reorganize their internal cognitive structures, reaching more elaborated stages. In the case of a person with deafness, the possibility of exchange can be compromised and knowledge about the construction of the temporal notion seems to be essential to enable a path of explanation about the difficulties they have regarding their cognitive development. Thus, based on the theory of Jean Piaget, the study intended to understand how the temporal notion constitutes as possible subject to the process of building the real, and examine, through empirical evaluation, if the difficulty in establishing symbolic exchanges caused by deafness would compromise the development of this notion. For this purpose, bibliographical research and empirical research were made, by the comparative evaluating between the performance of deaf and hearing subjects in relation to the construction of temporal notion. Two groups of subjects aged between 10 and 12 years were composed: one with three deaf subjects and another with 3 listeners. The assessment and analysis of the data were based on an experiment created by Piaget and his staff. The results showed that the listeners present responses from operative level, compatible with the age range in which they found themselves. In contrast, the deaf subjects showed responses of transition level, which indicates a situation of cognitive delay. We conclude that the potential compromise linguistic presented by deaf people, can hinder the activity representative causing delay in construction of temporal notion and consequently the development of thought. We conclude that the possible linguistic committal presented by deaf people can hinder the representative activity, causing delay in construction of temporal notion and consequently in the development of thought. In this sense, it seems that the Sign Language constitutes an important tool for deaf people because it allows symbolic exchanges that favor the cognitive development.

Situaçao atual dos grupos de pesquisa no Brasil que estudam a obra de Jean Piaget

Actual scenario of the brazilian research groups that study the work of Jean Piaget. This article aim the research that we made about the brazilian research groups dedicated in the study of the work of Jean Piaget in nowadays. This article show quantitative data collected throughout the research and a brief analysis upon it.