958 resultados para Bos primigenius indicus
Correlating Bayesian date estimates with climatic events and domestication using a bovine case study
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The tribe Bovini contains a number of commercially and culturally important species, such as cattle. Understanding their evolutionary time scale is important for distinguishing between post-glacial and domestication-associated population expansions, but estimates of bovine divergence times have been hindered by a lack of reliable calibration points. We present a Bayesian phylogenetic analysis of 481 mitochondrial D-loop sequences, including 228 radiocarbon-dated ancient DNA sequences, using a multi-demographic coalescent model. By employing the radiocarbon dates as internal calibrations, we co-estimate the bovine phylogeny and divergence times in a relaxed-clock framework. The analysis yields evidence for significant population expansions in both taurine and zebu cattle, European aurochs and yak clades. The divergence age estimates support domestication-associated expansion times (less than 12 kyr) for the major haplogroups of cattle. We compare the molecular and palaeontological estimates for the Bison-Bos divergence.
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We have shown that there is significant disparity in the expression of uncoupling proteins (UCP) 2 and 3 between modern-commercial and ancient-Meishan porcine genotypes, commercial pigs also have higher plasma triiodothyronine (T(3)) in on the first day of life. T(3) and the sympathetic nervous system are both known to regulate UCPs in rodents and humans; their role in regulating these proteins in the pig is unknown. This study examined whether thyroid hormone manipulation or administration of a selective beta3 adrenoceptor agonist (ZD) influenced plasma hormones, colonic temperature and UCP expression in adipose tissue of two breeds of pig. To mimic the differences observed in thyroid hormone status, piglets from Meishan and commercial litters were randomly assigned to control (1 ml/kg water), T(3) (10 mg/kg) (Meishan only), methimazole (a commonly used antithyroid drug) (50 mg/kg) (commercial only) or ZD (10 mg/kg) oral administration for the first 4 days of postnatal life. Adipose tissue UCP2/3 mRNA abundance was measured on day 4 using PCR. T(3) administration raised plasma T(3) concentrations and increased colonic temperature on day 4. UCP3 mRNA abundance was higher in Meishan, than commercial piglets (p = 0.042) and was downregulated following T(3) administration (p = 0.014). Irrespective of genotype, ZD increased UCP2 mRNA abundance (Meishan p = 0.05, commercial p = 0.03). Expression of neither UCP2 nor 3 was related to colonic temperature, regardless of treatment. In conclusion, we have demonstrated a dissociation between thyroid hormones and the sympathetic nervous system in the regulation of UCPs in porcine adipose tissue. We have also suggested that expression of adipose tissue UCP2 and 3 are not related to body temperature in piglets.
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The prebiotic effect of a pectic oligosaccharide-rich extract enzymatically derived from bergamot peel was studied using pure and mixed cultures of human faecal bacteria. This was compared to the prebiotic effect of fructo-oligosaccharides (FOS). Individual species of bifidobacteria and lactobacilli responded positively to the addition of the bergamot extract, which contained oligosaccharides in the range of three to seven. Fermentation studies were also carried out in controlled pH batch mixed human faecal cultures and changes in gut bacterial groups were monitored over 24 h by fluorescent in situ hybridisation, a culture-independent microbial assessment. Addition of the bergamot oligosaccharides (BOS) resulted in a high increase in the number of bifidobacteria and lactobacilli, whereas the clostridial population decreased. A prebiotic index (PI) was calculated for both FOS and BOS after 10 and 24 h incubation. Generally, higher PI scores were obtained after 10 h incubation, with BOS showing a greater value (6.90) than FOS (6.12).
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Taphonomic studies regularly employ animal analogues for human decomposition due to ethical restrictions relating to the use of human tissue. However, the validity of using animal analogues in soil decomposition studies is still questioned. This study compared the decomposition of skeletal muscle tissues (SMTs) from human (Homo sapiens), pork (Sus scrofa), beef (Bos taurus), and lamb (Ovis aries) interred in soil microcosms. Fixed interval samples were collected from the SMT for microbial activity and mass tissue loss determination; samples were also taken from the underlying soil for pH, electrical conductivity, and nutrient (potassium, phosphate, ammonium, and nitrate) analysis. The overall patterns of nutrient fluxes and chemical changes in nonhuman SMT and the underlying soil followed that of human SMT. Ovine tissue was the most similar to human tissue in many of the measured parameters. Although no single analogue was a precise predictor of human decomposition in soil, all models offered close approximations in decomposition dynamics.
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Species distribution models (SDM) are increasingly used to understand the factors that regulate variation in biodiversity patterns and to help plan conservation strategies. However, these models are rarely validated with independently collected data and it is unclear whether SDM performance is maintained across distinct habitats and for species with different functional traits. Highly mobile species, such as bees, can be particularly challenging to model. Here, we use independent sets of occurrence data collected systematically in several agricultural habitats to test how the predictive performance of SDMs for wild bee species depends on species traits, habitat type, and sampling technique. We used a species distribution modeling approach parametrized for the Netherlands, with presence records from 1990 to 2010 for 193 Dutch wild bees. For each species, we built a Maxent model based on 13 climate and landscape variables. We tested the predictive performance of the SDMs with independent datasets collected from orchards and arable fields across the Netherlands from 2010 to 2013, using transect surveys or pan traps. Model predictive performance depended on species traits and habitat type. Occurrence of bee species specialized in habitat and diet was better predicted than generalist bees. Predictions of habitat suitability were also more precise for habitats that are temporally more stable (orchards) than for habitats that suffer regular alterations (arable), particularly for small, solitary bees. As a conservation tool, SDMs are best suited to modeling rarer, specialist species than more generalist and will work best in long-term stable habitats. The variability of complex, short-term habitats is difficult to capture in such models and historical land use generally has low thematic resolution. To improve SDMs’ usefulness, models require explanatory variables and collection data that include detailed landscape characteristics, for example, variability of crops and flower availability. Additionally, testing SDMs with field surveys should involve multiple collection techniques.
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The objective of this study was to evaluate the possible use of biometric testicular traits as selection criteria for young Nellore bulls using Bayesian inference to estimate heritability coefficients and genetic correlations. Multitrait analysis was performed including 17,211 records of scrotal circumference obtained during andrological assessment (SCAND) and 15,313 records of testicular volume and shape. In addition, 50,809 records of scrotal circumference at 18 mo (SC18), used as an anchor trait, were analyzed. The (co) variance components and breeding values were estimated by Gibbs sampling using the Gibbs2F90 program under an animal model that included contemporary groups as fixed effects, age of the animal as a linear covariate, and direct additive genetic effects as random effects. Heritabilities of 0.42, 0.43, 0.31, 0.20, 0.04, 0.16, 0.15, and 0.10 were obtained for SC18, SCAND, testicular volume, testicular shape, minor defects, major defects, total defects, and satisfactory andrological evaluation, respectively. The genetic correlations between SC18 and the other traits were 0.84 (SCAND), 0.75 (testicular shape), 0.44 (testicular volume), -0.23 (minor defects), -0.16 (major defects), -0.24 (total defects), and 0.56 (satisfactory andrological evaluation). Genetic correlations of 0.94 and 0.52 were obtained between SCAND and testicular volume and shape, respectively, and of 0.52 between testicular volume and testicular shape. In addition to favorable genetic parameter estimates, SC18 was found to be the most advantageous testicular trait due to its easy measurement before andrological assessment of the animals, even though the utilization of biometric testicular traits as selection criteria was also found to be possible. In conclusion, SC18 and biometric testicular traits can be adopted as a selection criterion to improve the fertility of young Nellore bulls.
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Palisada flagellifera (Ceramiales, Rhodophyta) is recorded for the first time in the eastern Atlantic Ocean off Tenerife, La Gomera, La Palma and Fuerteventura, Canary Islands, Spain. The specimens were collected in 2006-2009 growing from the lower intertidal to subtidal zones to 2 m depth at sites exposed to wave action. The species possesses a palisade-like arrangement of cortical cells in cross section, lacks secondary pit connections between them, and has tetrasporangia produced by three fertile pericentral cells (the third and the fourth additional and the second that becomes fertile), and a right-angled arrangement of tetrasporangia. Gametangia were not observed. The phylogenetic relationships were inferred by analyses of the chloroplast-encoded rbcL gene sequences from 46 taxa. The Canarian and Brazilian P. flagellifera specimens formed a highly supported clade with a low level of genetic variation in the rbcL sequences (0.02-0.04%), confirming that they are the same taxonomic entity. This study expands the geographical distribution of P. flagellifera to the eastern Atlantic Ocean.
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Morphological and molecular studies were carried out on Palisada papillosa and P. perforata from the Canary Islands (type locality of P. perforata), Mexico and Brazil. The two species have been distinguished by features of their external morphology such as size and degree of compactness of the thalli, presence or absence of arcuate branches, branching pattern and basal system. A detailed morphological comparison between these taxa showed that none of the vegetative anatomical or reproductive characters was sufficient to separate these species. The presence or absence of cortical cells in a palisade-like arrangement, also previously used to. distinguish these species, is not applicable. The species present all characters typical of the genus, and both share production of the first pericentral cell underneath the basal cell of the trichoblast, production of two fertile pericentral cells (the second and the third additional, the first remaining sterile), spermatangial branches produced from one of two laterals on the suprabasal cell of trichoblasts, and the procarpbearing segment with four pericentral cells. Details of the procarp are described for the species for the first time. The phylogenetic position of these species was inferred by analysis of the chloroplast-encoded rbcL gene sequences from 39 taxa, using one other Rhodomelacean taxon and two Ceramiaceae as outgroups. Relationships within the clade formed by P. papillosa and P. perforata have not been resolved due to the low level of genetic variation in their rbcL sequences (0-0.4%). Considering this and the morphological similarities, we conclude that P. papillosa is a taxonomic synonym of P. perforata. The phylogenetic analyses also supported the nomenclatural transfer of two species of Chondrophycus to Palisada, namely, P. patentiramea (Montagne) Cassano, Senties, Gil-Rodriguez & M.T. Fujii comb. nov. and P. thuyoides (Kutzing) Cassano, Senties, Gil-Rodriguez & M.T. Fujii comb. nov.
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Syftet med den här undersökningen är att undersöka några pedagogers uppfattning om vilka olikafaktorer som kan påverka barns benägenhet att samarbeta och på vilket sätt dessa faktorer påverkar. Sommetod för att samla in data till studien har fyra pedagoger intervjuats. De berättar om i vilka situationerde sett barn samarbeta. Undersökningen redogör för olika faktorer som påverkar barns förmåga attsamarbeta. Dessa är miljön, gruppidentitet, kommunikation, tillit, gemensamt mål samt de vuxnasförhållningssätt. De olika påverkansfaktorerna samverkar med varandra men den övergripande faktornför barn är de vuxnas förhållningssätt då det är detta förhållningssätt som skapar förutsättningarna för deandra faktorerna. Undersökningen tar också upp skillnader mellan pedagoginitierat samarbete ochbarninitierat samarbete samt jämför pedagogernas erfarenhetsbaserade kunskap med denforskningsbaserade kunskapen.
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O contexto do funcionalismo público como fonte empregadora tem chamado crescente atenção, uma vez que as práticas de remuneração acima da média de mercado adotadas neste contexto vêm atraindo cada vez mais indivíduos altamente qualificados (Bender & Fernandes, 2006). Entretanto, trata-se de um setor que adota práticas de remuneração que também são caracterizadas pela desigualdade, uma vez que carreiras bem remuneradas co-existem com outras mal remuneradas, por vezes, dentro do mesmo espaço organizacional e executando tarefas similares. Estudos demonstram que, a priori, um ambiente de trabalho que favorece uma situação de desigualdade afeta negativamente diversos aspectos comportamentais dos funcionários que nele exercem atividades (e.g. De Cremer & Van Kleef, 2009; Peters & Van den Bos, 2008; Peters, Van den Bos & Bobocel, 2004). Desta forma, o presente estudo buscou entender como uma situação de desigualdade remuneratória – em que alguns membros se encontram em uma situação de overpayment, enquanto que outros na situação de underpayment – pode influenciar fatores como a autoestima e o comprometimento afetivo dos funcionários públicos com relação aos seus trabalhos. Um órgão público do Poder Executivo Federal, foi escolhido como lócus de pesquisa para analisar estes impactos. A metodologia utilizada na pesquisa teve uma natureza quantitativa e qualitativa. Numa primeira etapa, aplicaram-se 105 questionários a dois grupos distintos de servidores desse órgão público (um grupo tido como overpaid e outro tido como underpaid), tendo sido analisadas, por meio de regressões hierárquicas, os impactos da percepção de justiça salarial na auto-estima e no comprometimento dos funcionários. Posteriormente, realizaram-se 20 entrevistas com funcionários dos dois grupos com o intuito de aprofundar e discutir aspectos mais sensíveis relacionados com os resultados. Dessas análises foi possível confirmar a influência direta do senso de justiça remuneratória que o indivíduo possui na sua auto-estima e no seu comprometimento afetivo. Os resultados da pesquisa demonstram que representantes das carreiras bemremuneradas tendem a comparar-se com outras carreiras melhor remuneradas, evitando a comparação com os colegas do trabalho pertencentes a carreiras menos favorecidas. Entretanto, a influência que o sentimento de justiça tem em ambos os resultados comportamentais analisados é potencializada quanto maior for a percepção do indivíduo acerca da satisfação dos seus pares com o trabalho e com a sua remuneração. Observou-se ainda o efeito moderador da motivação epistêmica nesta relação. Esta pesquisa espera ter contribuído para melhor entender os impactos que políticas salariais podem ter nos funcionários públicos.
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O propósito dessa investigação foi o de estudar as situações objetivas e de auto-percepção em saúde bucal de idosos residentes em Instituições de Longa Permanência de Idosos (ILPIS) distribuídos em 11 municípios pertencentes as 5 regiões geográficas do Brasil. Metodologia: Trata-se de estudo seccional através de um censo com idosos institucionalizados no Brasil. Foram avaliados 1192 indivíduos, residentes em 36 Instituições de Longa Permanência de Idosos (ILPIS), distribuídas em 11 municípios. Deste universo, 587 (49,2%) responderam ao GOHAI. Foi aplicado questionário com questões subjetivas e sobre o comportamento em saúde bucal, além de levantamento epidemiológico seguindo critérios da Organização Mundial da Saúde (OMS). Foram realizados os testes de Mann-Whitney, Kruskal-Wallis, Exato de Fisher, Qui-quadrado e Regressão logística múltipla. Resultados: A idade média foi de 74,98 (+ 9,5). Destes, 51,4% (302) eram do sexo masculino e 152 (25,9) apresentavam alguma dependência. A média do CPOD foi de 28,8 (+ 5,5) e 54,5% (320) dos idosos eram edêntulos. Constatouse que 54,2% (318) e 74,1% (435) não usam nenhum tipo de prótese superior e inferior, respectivamente. O CPI e PIP mostraram que 64,4% (378) apresentaram todos os sextantes excluídos. O GOHAI mostrou que 75% (440) dos indivíduos apresentava auto-percepção positiva em saúde bucal. As variáveis última visita ao dentista (RP ajust=4,058; IC=1,526-10,789), presença de problemas gengivais (RP ajust=5,703; IC=1,754-18,544) e opinião sobre os dentes, as gengivas ou prótese (RP ajust=19,514; IC=5,075-75,041) permaneceram significativas no modelo após regressão logística múltipla. Conclusões: Observou-se predomínio da auto-percepção positiva em saúde bucal em detrimento das precárias condições bucais. Assim, para a população institucionalizada, o presente estudo recomenda a aplicação de levantamentos epidemiológicos e de auto-percepção para assegurar adequado planejamento nas ações de saúde bucal
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The objective of this work was to evaluate the effect of the variables number of recipients, synchronization protocol, reproductive efficiency indicators and pregnancy cost, in the economic effectiveness of in vivo and in vitro bovine embryo production. A simulation application was elaborated to allow the user to insert the input variable parameters. A basic scenario, from the efficiency traditional rates of in vivo (ET) and in vitro production (IVP) techniques of bovine embryos, was introduced in the software as a criterion to compare the results. This software was able to reproduce both ET and IVP scenarios. The embryo production was simulated through stochastic simulation. The optimal number of recipients using sensitivity analysis was determined. The net present value and cost per pregnancy were used as a decision parameter. The synchronization for fixed-time embryo transfer decreased the recipient idleness and, consequently, the final cost of pregnancy, in comparison to the traditional methodology. Foetal sexing must be associated to IVP of bovine embryos. In addition, the optimal recipient number per donor is variable and depends on data inserted in the system.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)