307 research outputs found

    Cross-species chromosome painting tracks the independent origin of multiple sex chromosomes in two cofamiliar Erythrinidae fishes

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    <p>Abstract</p> <p>Background</p> <p>The Erythrinidae fish family is characterized by a large variation with respect to diploid chromosome numbers and sex-determining systems among its species, including two multiple X<sub>1</sub>X<sub>2</sub>Y sex systems in <it>Hoplias malabaricus </it>and <it>Erythrinus erythrinus</it>. At first, the occurrence of a same sex chromosome system within a family suggests that the sex chromosomes are correlated and originated from ancestral XY chromosomes that were either homomorphic or at an early stage of differentiation. To identify the origin and evolution of these X<sub>1</sub>X<sub>2</sub>Y sex chromosomes, we performed reciprocal cross-species FISH experiments with two sex-chromosome-specific probes designed from microdissected X<sub>1 </sub>and Y chromosomes of <it>H. malabaricus </it>and <it>E. erythrinus</it>, respectively.</p> <p>Results</p> <p>Our results yield valuable information regarding the origin and evolution of these sex chromosome systems. Our data indicate that these sex chromosomes evolved independently in these two closed related Erythrinidae species. Different autosomes were first converted into a poorly differentiated XY sex pair in each species, and additional chromosomal rearrangements produced both X<sub>1</sub>X<sub>2</sub>Y sex systems that are currently present.</p> <p>Conclusions</p> <p>Our data provide new insights into the origin and evolution of sex chromosomes, which increases our knowledge about fish sex chromosome evolution.</p

    Saphenofemoral arteriovenous fistula as hemodialysis access

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    <p>Abstract</p> <p>Background</p> <p>An upper limb arteriovenous (AV) fistula is the access of choice for haemodialysis (HD). There have been few reports of saphenofemoral AV fistulas (SFAVF) over the last 10-20 years because of previous suggestions of poor patencies and needling difficulties. Here, we describe our clinical experience with SFAVF.</p> <p>Methods</p> <p>SFAVFs were evaluated using the following variables: immediate results, early and late complications, intraoperative and postoperative complications (up to day 30), efficiency of the fistula after the onset of needling and complications associated to its use.</p> <p>Results</p> <p>Fifty-six SFAVF fistulas were created in 48 patients. Eight patients had two fistulas: 8 patent (16%), 10 transplanted (20%), 12 deaths (24%), 1 low flow (2%) and 20 thrombosis (39%) (first two months of preparation). One patient had severe hypotension during surgery, which caused thrombosis of the fistula, which was successfully thrombectomised, four thrombosed fistulae were successfully thrombectomised and revised on the first postoperative day. After 59 months of follow-up, primary patency was 44%.</p> <p>Conclusion</p> <p>SFAVF is an adequate alternative for patients without the possibility for other access in the upper limbs, allowing efficient dialysis with good long-term patency with a low complication rate.</p

    Bayesian inference in genetic parameter estimation of visual scores in Nellore beef-cattle

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    The aim of this study was to estimate the components of variance and genetic parameters for the visual scores which constitute the Morphological Evaluation System (MES), such as body structure (S), precocity (P) and musculature (M) in Nellore beef-cattle at the weaning and yearling stages, by using threshold Bayesian models. The information used for this was gleaned from visual scores of 5,407 animals evaluated at the weaning and 2,649 at the yearling stages. The genetic parameters for visual score traits were estimated through two-trait analysis, using the threshold animal model, with Bayesian statistics methodology and MTGSAM (Multiple Trait Gibbs Sampler for Animal Models) threshold software. Heritability estimates for S, P and M were 0.68, 0.65 and 0.62 (at weaning) and 0.44, 0.38 and 0.32 (at the yearling stage), respectively. Heritability estimates for S, P and M were found to be high, and so it is expected that these traits should respond favorably to direct selection. The visual scores evaluated at the weaning and yearling stages might be used in the composition of new selection indexes, as they presented sufficient genetic variability to promote genetic progress in such morphological traits

    Relative contribution of effects included in contemporary groups for adjusted and actual 120-day and 210-day weights in Nelore cattle in Brazil

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    The objective of this research was to estimate the relative magnitude of effects included in contemporary groups (CG) and their interactions with adjusted and actual 120 d and 210 d weights in 72,731 male and female Nelore calves born from 1985 to 2005 in 40 herds from PMGRN (Genetic Improvement Program of Nelore). Ten models with different CG structures were compared. The analyses were done using the general linear models (GLM) procedure run in SAS software. All of the effects included in the CG for each model were significant (p < 0.001) for the four traits analyzed. Inclusion of semester or trimester of birth as part of a CG was more appropriate than its use as an independent effect in the model because it accounted for interactions with the other effects in the CG. Calf sex (CS) and dam age at calving (DAC) had similar effects across the models, which suggested independence from other effects in these models. The corresponding age deviation effect had a larger impact on actual weight at 120 d than any other effect in all of the models tested. The use of actual weights in models with no CS effect in CG provides an alternative that would allow better genetic connectedness among CGs and greater accuracy in genetic evaluations

    Primary healthcare and the construction of thematic health networks: what role can they play?

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    The enhancement of primary healthcare has been a core strategy for the empowerment of the Brazilian Unified Health System (SUS). Recent guidelines issued by OPAS and the Ministry of Health highlight the role it has played as a thematic communication network center, a regulating agent for the access and use of services required for comprehensive healthcare. Sponsored by PPSUS/Fapesp, this study examines the possibilities of the primary healthcare network exercising such a strategic function. Life narratives involving 15 regular users were produced in two cities of ABC Paulista, which have adopted the Family Health Strategy for the organization of their primary healthcare networks. The study presents three main findings: the primary healthcare network serves as an outpost of SUS by producing user values even for high complexity service users; the primary network is perceived is a place for simple care needs; there is shared impotence between users and teams when it comes to the network functioning as the coordinator of care, indicating that it does not possess the technological, operational and organizational material conditions or symbolic conditions (values, meanings, and representations) to be in a central position in the coordination of thematic healthcare networks.O fortalecimento da atenção básica tem sido valorizado como estratégia central para a construção do SUS. Diretrizes recentes emanadas pela OPAS e pelo MS destacam seu papel como centro de comunicação de redes temáticas, como reguladora do acesso e utilização dos serviços necessários para a integralidade do cuidado. O presente estudo, financiado com recursos PPSUS/Fapesp, problematiza as possibilidades da rede básica exercer tal função estratégica. Foram produzidas narrativas de vida de 15 usuários altamente utilizadores de serviços de saúde em dois municípios do ABC paulista, que adotaram a Estratégia de Saúde da Família para organização de suas redes básicas. O estudo apresenta três achados principais: a rede básica funciona como posto avançado do SUS, produzindo valores de uso mesmo para os pacientes utilizadores de serviços de alta complexidade; a rede básica é vista como lugar de coisas simples; há uma impotência compartilhada entre usuários e equipes quando se trata da rede básica funcionar como coordenadora do cuidado, indicando como ela não reúne condições materiais (tecnológicas, operacionais, organizacionais) e simbólicas (valores, significados e representações) de deter a posição central da coordenação das redes temáticas de saúde.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de Medicina PreventivaInstituto Superior de Ciências do Trabalho e da Empresa Instituto Universitário de Lisboa Faculdade de Ciências Médicas Departamento de Saúde ColetivaUniversidade Estadual de Campinas Faculdade de Ciências Médicas Departamento de Saúde ColetivaUNIFESP, EPM, Depto. de Medicina PreventivaSciEL
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