Estimação da zona de conforto térmico de ovinos deslanados

Conduziu-se um experimento na câmara bioclimática do Centro de Estudos Bioclimáticos da Universidade Estadual do Sudoeste da Bahia – Brasil, cujo objetivo foi estabelecer a zona de conforto térmico para ovinos deslanados. Em um experimento completamente casualizado, sete fêmeas da raça Santa Inês (repetições) foram expostas durante três dias consecutivos a cada um dos sete tratamentos (temperaturas de 10, 15, 20, 25, 30, 35 e 40oC na umidade do ar fixa de 65%), Entre cada tratamento, os animais ficavam ao ar livre por cinco dias para eliminar o efeito residual. Foram coletadas as temperaturas de bulbo seco e úmido e de globo negro e calculados o THI e BGHI. Também, se mediu as variáveis fisiológicas freqüência respiratória, freqüência cardíaca e temperatura retal.Os testes de adaptabilidade utilizados foram os de Ibéria, Benezra e Benezra modificado. Concluiu-se que a zona de conforto térmico para ovinos deslanados está entre 15 e 25oC sob 65% de UR

Comprehensive analysis of epigenetic clocks reveals associations between disproportionate biological ageing and hippocampal volume

The concept of age acceleration, the difference between biological age and chronological age, is of growing interest, particularly with respect to age-related disorders, such as Alzheimer’s Disease (AD). Whilst studies have reported associations with AD risk and related phenotypes, there remains a lack of consensus on these associations. Here we aimed to comprehensively investigate the relationship between five recognised measures of age acceleration, based on DNA methylation patterns (DNAm age), and cross-sectional and longitudinal cognition and AD-related neuroimaging phenotypes (volumetric MRI and Amyloid-β PET) in the Australian Imaging, Biomarkers and Lifestyle (AIBL) and the Alzheimer’s Disease Neuroimaging Initiative (ADNI). Significant associations were observed between age acceleration using the Hannum epigenetic clock and cross-sectional hippocampal volume in AIBL and replicated in ADNI. In AIBL, several other findings were observed cross-sectionally, including a significant association between hippocampal volume and the Hannum and Phenoage epigenetic clocks. Further, significant associations were also observed between hippocampal volume and the Zhang and Phenoage epigenetic clocks within Amyloid-β positive individuals. However, these were not validated within the ADNI cohort. No associations between age acceleration and other Alzheimer’s disease-related phenotypes, including measures of cognition or brain Amyloid-β burden, were observed, and there was no association with longitudinal change in any phenotype. This study presents a link between age acceleration, as determined using DNA methylation, and hippocampal volume that was statistically significant across two highly characterised cohorts. The results presented in this study contribute to a growing literature that supports the role of epigenetic modifications in ageing and AD-related phenotypes

Análise fatorial de medidas morfométricas em ovinos tipo Santa Inês

This study was made with the objective of realize a morphological evaluation of Santa Inês like ovines using the factorial analysis. Twenty two sheeps were used: 12 ewes and 10 rams. The measurements were taken every fifteen days, after the animals reached the average live weight of 26.8 ± 5.2 kg and were 4.5 months old. The following variables were measured: withers height, hindquarters height, back height; body length, hindquarters length, back length, scrotum length; hindquarters width, breast width; scrotal perimeter and thoracic perimeter. The factorial analysis was used in order to verify the existence of main relationships among morphometric measurements. Five factors were found and their respective communalities. The factorial analysis was efficient to group the linear measurements made ease the visualization of the main relationships among morphological measurements. These results can be of great importance in the determination of body attributes of sheep in both reproduction and meat production.Objetivou-se, neste estudo, realizar a avaliação morfológica de ovinos tipo Santa Inês, adotando-se a análise fatorial. Foram utilizados 22 carneiros, 12 fêmeas e 10 machos inteiros. As medidas foram feitas, quinzenalmente, quando os animais atingiram peso vivo médio de 26,8 ± 5,2 kg e uma faixa etária de 4,5 meses. Foram medidos: altura da cernelha, da garupa e do costado; comprimento do corpo, da garupa, do dorso e escrotal; largura de garupa, do peito e púbis; perímetro escrotal e torácico. A analise fatorial foi empregada para verificar a existência de relações importantes entre as medidas morfométricas. Foram obtidos 5 fatores e as respectivas comunalidades. A análise fatorial foi eficiente em agrupar as medidas lineares, facilitando a visualização de relações importantes entre as medidas morfométricas, o que pode ser de grande importância para a determinação dos atributos corporais de carneiros destinados à reprodução e recria

The SAMI galaxy survey: Bayesian inference for gas disc kinematics using a hierarchical Gaussian mixture model

We present a novel Bayesian method, referred to as BLOBBY3D, to infer gas kinematics that mitigates the effects of beam smearing for observations using integral field spectroscopy. The method is robust for regularly rotating galaxies despite substructure in the gas distribution. Modelling the gas substructure within the disc is achieved by using a hierarchical Gaussian mixture model. To account for beam smearing effects, we construct a modelled cube that is then convolved per wavelength slice by the seeing, before calculating the likelihood function. We show that our method can model complex gas substructure including clumps and spiral arms. We also show that kinematic asymmetries can be observed after beam smearing for regularly rotating galaxies with asymmetries only introduced in the spatial distribution of the gas. We present findings for our method applied to a sample of 20 star-forming galaxies from the SAMI Galaxy Survey. We estimate the global H α gas velocity dispersion for our sample to be in the range σ¯v ∼[7, 30] km s−1. The relative difference between our approach and estimates using the single Gaussian component fits per spaxel is σ¯v/σ¯v = −0.29 ± 0.18 for the H α flux-weighted mean velocity dispersion

Hydraulic traits explain differential responses of Amazonian forests to the 2015 El Niño-induced drought

Reducing uncertainties in the response of tropical forests to global change requires understanding how intra- and interannual climatic variability selects for different species, community functional composition and ecosystem functioning, so that the response to climatic events of differing frequency and severity can be predicted. Here we present an extensive dataset of hydraulic traits of dominant species in two tropical Amazon forests with contrasting precipitation regimes – low seasonality forest (LSF) and high seasonality forest (HSF) – and relate them to community and ecosystem response to the El Niño–Southern Oscillation (ENSO) of 2015. Hydraulic traits indicated higher drought tolerance in the HSF than in the LSF. Despite more intense drought and lower plant water potentials in HSF during the 2015-ENSO, greater xylem embolism resistance maintained similar hydraulic safety margin as in LSF. This likely explains how ecosystem-scale whole-forest canopy conductance at HSF maintained a similar response to atmospheric drought as at LSF, despite their water transport systems operating at different water potentials. Our results indicate that contrasting precipitation regimes (at seasonal and interannual time scales) select for assemblies of hydraulic traits and taxa at the community level, which may have a significant role in modulating forest drought response at ecosystem scales. © 2019 The Authors. New Phytologist © 2019 New Phytologist Trus

Grupo genético, sistema de acasalamento e efeitos genéticos aditivos e não-aditivos nas características de musculosidade da carcaça de novilhos oriundos do cruzamento rotativo Charolês × Nelore Genetic group, breeding system and additive and non-additive genetic effects on characteristics that express muscularity of steer carcasses derived from Charolais × Nellore rotative crossbreeding

Foram avaliadas as carcaças de 800 novilhos oriundos do cruzamento rotativo entre as raças Charolesa e Nelore abatidos aos 2 anos de idade. As características avaliadas foram: conformação, espessura de coxão, perímetro de braço, área de olho-de-lombo e área de olho-de-lombo dividida por 100 kg de peso da carcaça fria (AOL100). Na análise dos dados, consideraram-se dois modelos: o Modelo 1 incluiu os efeitos genéticos de sistema de acasalamento e grupo genético do novilho aninhado em sistema de acasalamento e o Modelo 2 correspondeu ao Modelo 1, porém o sistema de acasalamento e o grupo genético foram substituídos pelas covariáveis representativas da porcentagem da raça Charolesa no indivíduo e na sua mãe e da porcentagem de heterozigose no indivíduo e na sua mãe. Pela análise do Modelo 1, novilhos charoleses foram superiores aos nelores em todas as características avaliadas. A heterose retida foi significativa para conformação (4,2%), espessura de coxão (3,2%), perímetro de braço (4,2%), área de olho-de-lombo (7,3%) e AOL100 (-6,7%). O efeito genético aditivo individual da raça Charolesa em relação à Nelore foi de 1,89 pontos para conformação, 1,37 cm para espessura de cochão, 2,55 cm para perímetro de braço, 12,70 cm² para área de olho-de-lombo e 3,13 cm² para AOL100. O efeito genético heterótico individual (em relação à média dos definidos) foi de 3,9% para conformação, 3,8% para espessura de cochão, 3,1% para perímetro de braço e 9,8% para área de olho-de-lombo. A heterose materna é significativa apenas para perímetro de braço (1,6%) e AOL100 (-5,4%). Os efeitos genéticos não-aditivos, representados por epistasia e ligação gênica, não influenciam as características avaliadas.<br>The carcasses of 800 steers derived from rotational crossbreeding between Charolais and Nellore breeds, slaughtered at two years of age, were evaluated. The evaluated characteristics were the following: conformation, cushion thickness, arm perimeter, Longissimus dorsi area, Longissimus dorsi area divided by 100 kg of cold carcass weight (AOL100). Two models were used for the data analyses: Model 1 included the genetic effects of the breeding system and steer genetic group nested within the breeding system and Model 2 corresponded to Model 1, but the breeding and genetic group were substituted by the covariables corresponding to the percentage of Charolais breed of the individual and its mother and the percentage of heterozygosis of the individual and its mother. From the analysis in Model 1, Charolais steers were superior to the Nelores in all assessed traits. The retained heterosis was significant for conformation (4.2%), cushion thickness (3.2%), arm perimeter (4.2%), Longissimus dorsi area (7.3%) and AOL100 (-6.7%). The individual additive genetic effect of Charolais breed regarded to Nelore was 1.89 points for conformation, 1.37 cm for cushion thickness, 2.55 cm for arm perimeter, 12.70 cm&sup2; for Longissimus dorsi area and 3.13 cm&sup2; for AOL100. The individual heterotic genetic effect (regarded to the straightbred mean) was 3.9% for conformation, 3.8% for cushion thickness, 3.1% for arm perimeter and 9.8% for Longissimus dorsi area. Maternal heterosis is significant only for arm perimeter (1.6%) and AOL100 (-5.4%). The nonadditive genetic effects, represented by epistasis and linkage, do not influence the evaluated characteristics