An Upsilon Point in a Spin Model

We present analytic evidence for the occurrence of an upsilon point, an infinite checkerboard structure of modulated phases, in the ground state of a spin model. The structure of the upsilon point is studied by calculating interface--interface interactions using an expansion in inverse spin anisotropy.Comment: 18 pages ReVTeX file, including 6 figures encoded with uufile

Relação entre polimorfismos no gene da leptina, ganho de peso e concentração sérica de leptina em bovinos de corte.

O objetivo do trabalho é estabelecer a relação de polimorfismos no gene da leptina com a quantidade de leptina sérica e ganho de peso durante o confinamento, visando a utilização de dados obtidos em programas de seleção animal. Os bovinos confinados utilizados na pesquisa serão provenientes da Fazenda Tuju Puitan. Serão objetos da pesquisa 100 animais com idade média de 12 meses

Fresh look at randomly branched polymers

We develop a new, dynamical field theory of isotropic randomly branched polymers, and we use this model in conjunction with the renormalization group (RG) to study several prominent problems in the physics of these polymers. Our model provides an alternative vantage point to understand the swollen phase via dimensional reduction. We reveal a hidden Becchi-Rouet-Stora (BRS) symmetry of the model that describes the collapse ($\theta$-)transition to compact polymer-conformations, and calculate the critical exponents to 2-loop order. It turns out that the long-standing 1-loop results for these exponents are not entirely correct. A runaway of the RG flow indicates that the so-called $\theta^\prime$-transition could be a fluctuation induced first order transition.Comment: 4 page

Polymorphisms Related to Bovine Leptin Gene and Association with Productive and Reproductive Traits in Nellore Heifers

The identification of genes and polymorphisms in female zebu related to the leptin gene that may be involved in better productive and reproductive performances is relevant to the livestock and economic sector. Thus, the objective of this study was to evaluate the SNP markers (T954M and C305T) and the BM1500 microsatellite and to analyze their associations with the traits of body weight, age at first calving (AFC), calving interval (CI), and reproductive efficiency (RE) in Nellore heifers. DNA extraction was performed, followed by the amplification of all markers. Association analyses were carried out with each marker and each traits separately. The result showed that no significant association was found between the reproductive traits and all markers and between body weight and both SNP markers. For the BM1500 microsatellite, the effect of the allele 138 (p=0.0383) on body weight was observed, with the growth curve for this allele being related to the lower asymptotic weight. Therefore, the BM1500 microsatellite marker was the only one with a significant association with a productive trait providing information about the condition of body weight in Nellore heifers

Use of segmented polynomials to study the lactation curve of Murrah and their crossed breeds of buffaloes under an extensive production system in the State of Sao Paulo

The objective of this study was to evaluate the use of segmented polynomials, described by the two models quadratic-quadratic (PSQQ) and that with three quadratic segments (PSQQQ), for adjustment of the mean lactation curve of Murrah females and their crosses under a system of extensive production, with once daily milking. Studies of this nature in buffaloes are practically non-existent. Milk production data from twelve herds, including 1280 lactations and 8839 test-day milk weights were analyzed. Test days were spaced at 30-day intervals, during the period from 1995 to 2001. Lactations included in the analysis were based on a minimum of four and a maximum of nine test days. For the PSQQ model, the mean curve reached its “Knot” (junction point between the segments) in the second month of lactation, while for the PSQQ model the “Knots” were estimated to be in the second and fourth months. The parameters of each function were estimated by interactive procedures, using PROC REG of SAS. Criteria used to verify the goodness of fit for each function were: adjusted coefficient of determination (R2A); lack of fit test (LOF); and graphic distribution of residuals and of residual lag. The two models closely described variations in milk production throughout the lactation with the lack of fit tests not significant. The coefficients of determination were practically identical for both models under study (R2A = 91.3%). (Text in Portuguese)

Protein sequence and structure: Is one more fundamental than the other?

We argue that protein native state structures reside in a novel "phase" of matter which confers on proteins their many amazing characteristics. This phase arises from the common features of all globular proteins and is characterized by a sequence-independent free energy landscape with relatively few low energy minima with funnel-like character. The choice of a sequence that fits well into one of these predetermined structures facilitates rapid and cooperative folding. Our model calculations show that this novel phase facilitates the formation of an efficient route for sequence design starting from random peptides.Comment: 7 pages, 4 figures, to appear in J. Stat. Phy

Valores econômicos em sistemas de produção de bovinos de leite utilizados em pequenas propriedades no Rio Grande do Sul.

O objetivo deste estudo foi calcular valores econômicos (VEs) para dois sistemas de produção utilizados em pequenas propriedades rurais no Rio Grande do Sul

Ovelha pantaneira, um grupamento genético naturalizado do Estado do Mato Grosso do Sul, Brasil.

O grupamento genético ovino pantaneiro tem origem no Pantanal, bioma singular que exerce seleção natural intensa nos animais domésticos naturalizados. Devido às condições ambientais reinantes na planície alagada, os ovinos pantaneiros sul-mato-grossenses desenvolveram características adaptativas e produtivas que justificam a sua conservação. Os estudos até o momento concentraram-se nos aspectos morfométricos, para definição de padrões raciais, e no desempenho produtivo (carne, lã, leite, peles, reprodução e sanidade), que resultaram em bons resultados comparados a raças ovinas exóticas. Os estudos de características genéticas, para orientar os programas de seleção e melhoramento, estão em andamento, com o objetivo de complementar os estudos científicos que subsidiam o registro da raça Ovelha Pantaneira