294 research outputs found

    LP/HT metamorphism as a temporal marker of change of deformation style within the Late Palaeozoic accretionary wedge of central Chile

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    A Late Palaeozoic accretionary prism, formed at the southwestern margin of Gondwana from Early Carboniferous to Late Triassic, comprises the Coastal Accretionary Complex of central Chile (34–41°S). This fossil accretionary system is made up of two parallel contemporaneous metamorphic belts: a high‐pressure/low temperature belt (HP/LT – Western Series) and a low pressure/high temperature belt (LP/HT – Eastern Series). However, the timing of deformation events associated with the growth of the accretionary prism (successive frontal accretion and basal underplating) and the development of the LP/HT metamorphism in the shallower levels of the wedge are not continuously observed along this paired metamorphic belt, suggesting the former existence of local perturbations in the subduction regime. In the Pichilemu region, a well‐preserved segment of the paired metamorphic belt allows a first order correlation between the metamorphic and deformational evolution of the deep accreted slices of oceanic crust (blueschists and HP greenschists from the Western Series) and deformation at the shallower levels of the wedge (the Eastern Series). LP/HT mineral assemblages grew in response to arc‐related granitic intrusions, and porphyroblasts constitute time markers recording the evolution of deformation within shallow wedge material. Integrated P–T–t–d analysis reveals that the LP/HT belt is formed between the stages of frontal accretion (D1) and basal underplating of basic rocks (D2) forming blueschists at c. 300 Ma. A timeline evolution relating the formation of blueschists and the formation and deformation of LP/HT mineral assemblages at shallower levels, combined with published geochronological/thermobarometric/geochemistry data suggests a cause–effect relation between the basal accretion of basic rocks and the deformation of the shallower LP/HT belt. The S2 foliation that formed during basal accretion initiated near the base of the accretionary wedge at ~30 km depth at c. 308 Ma. Later, the S2 foliation developed at c. 300 Ma and ~15 km depth shortly after the emplacement of the granitoids and formation of the (LP/HT) peak metamorphic mineral assemblages. This shallow deformation may reflect a perturbation in the long‐term subduction dynamics (e.g. entrance of a seamount), which would in turn have contributed to the coeval exhumation of the nearby blueschists at c. 300 Ma. Finally, 40Ar–39Ar cooling ages reveal that foliated LP/HT rocks were already at ~350 °C at c. 292 Ma, indicating a rapid cooling for this metamorphic system.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/115992/1/jmg12166-sup-0001-FigS1-S5.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/115992/2/jmg12166_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/115992/3/jmg12166.pd

    Morphological traits and type of dairy goats registered in Brazil from 1976 to 2009.

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    Abstract: Data from 2439 goats of the Saanen, Alpine, Anglo Nubian and Toggenburg breeds recorded from 1976 to 2009 by the Association of Goats and Sheep Breeders of Minas Gerais were used in principal component analysis. After consistency of data, six morphological variables (thorax perimeter, body length, withers height, height, width and length of the rump) and 12 variables related to breed standard score and fitness (breed characteristic, head, palette and topline, feet and legs, dairy type, body capacity, udder, rear and front ligament, udder texture, teat and final score) were analyzed. Based on the magnitude of the eigenvalue (lower than 0.7), eleven variables considered redundant were discarded, resulting in reduced costs of technician labor to evaluate the animals. Maintenance of records on height, length, rump width, breed characteristic, dairy type, front ligament and udder texture is recommended

    Identification of morphofunctional traits in Mangalarga Marchador horse using principal component analysis

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    Dados de 14.288 animais da ra?a Mangalarga Marchador, nascidos de 1990 a 2005, foram utilizados para avaliar a redu??o da dimensionalidade do espa?o multivariado para caracter?sticas morfofuncionais, por meio da an?lise de componentes principais. Foram consideradas as caracter?sticas: altura na cernelha, altura na garupa, comprimento da cabe?a, comprimento do pesco?o, comprimento do dorso, comprimento da garupa, comprimento da esp?dua, comprimento do corpo, largura da cabe?a, largura das ancas, per?metro do t?rax, per?metro da canela e a pontua??o da marcha. Para tais caracter?sticas, obtiveram-se sete componentes principais, a partir da matriz de correla??o, que apresentaram vari?ncia inferior a 0,7 (autovalor inferior a 0,7). Isso sugere sete vari?veis para descarte, por apresentarem maiores coeficientes de pondera??o, em valor absoluto, a partir do ?ltimo componente principal. A raz?o para isso ? que vari?veis altamente correlacionadas com os componentes de menor vari?ncia representam varia??o praticamente insignificante. Com base nesses resultados, recomendam-se as seguintes caracter?sticas para serem mantidas em trabalhos futuros com esta base de dados: pontua??o da marcha, altura na garupa, comprimento do dorso, comprimento da garupa, largura da cabe?a e per?metro da canela.Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG)Empresa de Pesquisa Agropecu?ria de Minas Gerais (EPAMIG)Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq)Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)Records from 14,288 animals of the Mangalarga Marchador breed, born from 1990 to 2005, were used to discard morphofunctional traits in a principal component analysis. The following traits were used: height at withers, height at croup, lengths of head, neck, back, croup, hip length and body, widths of head, hip width, thorax perimeter, cannon bone circumference and gait score. For the traits considered it was observed that 7 principal components showed variation lower than 0.7; suggesting that seven variables could be discarded. The reason is that when variable are highly correlated with the principal components of smaller variance, their variation is practically insignificant. Based on those results the recommendation is to maintain the following traits for future research with this database: gait score, height at croup, length of back, length of croup, width of head and cannon bone circumference

    CalogĂȘnese de tecidos foliares de hĂ­bridos de palma de Ăłleo (Elaeis oleifera x E. guineensis) visando a embriogĂȘnese somĂĄtica.

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    Neste trabalho, objetivou-se avaliar a responsividade de segmentos foliares de dois hĂ­bridos interespecĂ­ficos de Elaeis oleifera x E. guineensis quanto Ă  formação de calos visando a embriogĂȘnese somĂĄtica

    Genomic variation in baboons from central Mozambique unveils complex evolutionary relationships with other Papio species

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    Background: Gorongosa National Park in Mozambique hosts a large population of baboons, numbering over 200 troops. Gorongosa baboons have been tentatively identified as part of Papio ursinus on the basis of previous limited morphological analysis and a handful of mitochondrial DNA sequences. However, a recent morphological and morphometric analysis of Gorongosa baboons pinpointed the occurrence of several traits intermediate between P. ursinus and P. cynocephalus, leaving open the possibility of past and/or ongoing gene flow in the baboon population of Gorongosa National Park. In order to investigate the evolutionary history of baboons in Gorongosa, we generated high and low coverage whole genome sequence data of Gorongosa baboons and compared it to available Papio genomes. Results: We confirmed that P. ursinus is the species closest to Gorongosa baboons. However, the Gorongosa baboon genomes share more derived alleles with P. cynocephalus than P. ursinus does, but no recent gene flow between P. ursinus and P. cynocephalus was detected when available Papio genomes were analyzed. Our results, based on the analysis of autosomal, mitochondrial and Y chromosome data, suggest complex, possibly male-biased, gene flow between Gorongosa baboons and P. cynocephalus, hinting to direct or indirect contributions from baboons belonging to the “northern” Papio clade, and signal the presence of population structure within P. ursinus. Conclusions: The analysis of genome data generated from baboon samples collected in central Mozambique highlighted a complex set of evolutionary relationships with other baboons. Our results provided new insights in the population dynamics that have shaped baboon diversity

    Plasma carotenoids, retinol, and tocopherols and postmenopausal breast cancer risk in the Multiethnic Cohort Study: a nested case-control study

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    Assessments by the handful of prospective studies of the association of serum antioxidants and breast cancer risk have yielded inconsistent results. This multiethnic nested case-control study sought to examine the association of plasma carotenoids, retinol, and tocopherols with postmenopausal breast cancer risk.From the biospecimen subcohort of the Multiethnic Cohort Study, 286 incident postmenopausal breast cancer cases were matched to 535 controls on age, sex, ethnicity, study location (Hawaii or California), smoking status, date/time of collection and hours of fasting. We measured prediagnostic circulating levels of individual carotenoids, retinol, and tocopherols. Conditional logistic regression was used to compute odds ratios and 95% confidence intervals.Women with breast cancer tended to have lower levels of plasma carotenoids and tocopherols than matched controls, but the differences were not large or statistically significant and the trends were not monotonic. No association was seen with retinol. A sensitivity analysis excluding cases diagnosed within 1 year after blood draw did not alter the findings.The lack of significant associations in this multiethnic population is consistent with previously observed results from less racially-diverse cohorts and serves as further evidence against a causal link between plasma micronutrient concentrations and postmenopausal breast cancer risk
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