Morphological and morphometric analysis of skeletal muscle between male and female young adult Colossoma macropomum (Characiformes: Serrasalmidae)

ABSTRACT This study aimed to evaluate muscle organization in tambaqui in order to describe the muscle growth process. We analyzed the morphometric pattern of fibers from white muscle of young-adults (300 days) by smaller diameter. The organization of white muscle exhibited a typical morphological pattern found in other fish species. Heavier animals showed higher frequency of larger diameter fibers (>50 μm ) and smaller animals had higher frequency of smaller diameter fibers (50 μm ) than males. However, there was no difference between body weight and sex (P =0.8). Our results suggest that muscle growth is by hypertrophy and hyperplasia due to a mosaic appearance from different diameters fibers, which is characteristic of large size fish species

Dimensionality reduction for the quantitative evaluation of a smartphone-based Timed Up and Go test

The Timed Up and Go is a clinical test to assess mobility in the elderly and in Parkinson's disease. Lately instrumented versions of the test are being considered, where inertial sensors assess motion. To improve the pervasiveness, ease of use, and cost, we consider a smartphone's accelerometer as the measurement system. Several parameters (usually highly correlated) can be computed from the signals recorded during the test. To avoid redundancy and obtain the features that are most sensitive to the locomotor performance, a dimensionality reduction was performed through principal component analysis (PCA). Forty-nine healthy subjects of different ages were tested. PCA was performed to extract new features (principal components) which are not redundant combinations of the original parameters and account for most of the data variability. They can be useful for exploratory analysis and outlier detection. Then, a reduced set of the original parameters was selected through correlation analysis with the principal components. This set could be recommended for studies based on healthy adults. The proposed procedure could be used as a first-level feature selection in classification studies (i.e. healthy-Parkinson's disease, fallers-non fallers) and could allow, in the future, a complete system for movement analysis to be incorporated in a smartphone

Microsatellite analysis of the parental contribution of Piaractus mesopotamicus to the production of offspring in the semi-natural system of reproduction

The objective of this study was to evaluate the genetic diversity and the parental contribution of Piaractus mesopotamicus in the production of offspring in the semi-natural system of reproduction. Twenty parental fishes (eleven males and nine females) and the total of 100 larvae were evaluated by microsatellite marker. The parents and offspring had thirty-one alleles and heterozygosity of 0.550 and 0.563, respectively. The females were fertilised by two up to six males while the males fertilised three up to five females. The contribution of the females and males to the offspring were 66.6 and 58%, respectively. Such results indicated no loss in the genetic variability in the offspring, and the parents had multiple paternity and reasonable contribution to the offspring production.<br>O objetivo deste trabalho foi avaliar a diversidade genética e a contribuição parental de Piaractus mesopotamicus na produção de descendência no sistema seminatural de reprodução. Vinte peixes parentais (onze machos e nove fêmeas) e o total de 100 larvas foram avaliados por meio do marcador microssátelite. Os parentais e a progênie tiveram trinta e um alelos e heterozigosidade de 0,550 e 0,563, respectivamente. As fêmeas foram fertilizadas por dois até seis machos enquanto machos fertilizaram três até cinco fêmeas. A contribuição de fêmeas e machos para a descendência seja 66,6 e 58,0%, respectivamente. Tais resultados não indicam diminuição da variabilidade genética na progênie e os parentais apresentaram paternidade múltipla e razoável contribuição à produção de descendência