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The objective of this research was to try to unveil the relationship between production traits and genotypic proportions of crossbred dairy cattle using principal component analysis (PCA) and cluster analysis. The herd consists of crossbred animals of Holstein (H) and Zebu (Z) (Gir and Guzerat) in different genotypic proportions; the composition of which varies from 12.5 to 100.0 % of the genetic group H. For this study, 834 milk production records from 257 cows from the years 1997 to 2014 were analyzed. The animals were all managed at a farm located in northeastern Brazil. The variables in the PCA were total milk yield per lactation (MY), milk yield adjusted to 305 days (MY305), lactation length (LL), and proportion of H and Z breeding. This analysis reduced the size of the sample space from the original five variables to two principal components (PCs) that together explained 89.4 % of the total variation. MY, MY305, LL, and genotypic proportion of H all contributed positively to PC1. The genotypic proportion of Z contributed negatively, which established a contrast between H and Z. Further cluster analysis identified two distinct groups when considering production performance and genotype of the animals. The high-performance group was predominantly Holstein breeding, while the lower performing group consisted mostly of Zebu. Under the environmental and management conditions in which this research was conducted, the best performances for the traits considered were achieved from cows whose genotypic proportion was between 38.0 and 94.0 % Holstein breeding.

Dalbergia ecastaphyllum is a native Brazil plant with importance for beekeeping, and widely used in folk medicine. For the first time, the extracts of this plant were assessed for the presence of hydrophilic and lipophilic antioxidants, as well as inhibition of tyrosinase, free radicals scavenging and sunscreen protection. The antioxidant activity was evaluated by free radical scavenging (DPPH) and β-carotene bleaching assay. The tyrosinase inhibitory activity was evaluated and calculated the EC50. The photoprotective activity was measured using different concentrations of D. ecastaphyllum extracts. The Sun Protection Factor (SPF) of the samples was higher than 6, and the sample from Ilhéus showed the most pronounced photoprotective effect. Sample from Canavieiras presented the highest antioxidant activity by free radical scavenging DPPH and β-carotene bleaching method, with 92.41% and 48.34%, respectively. All samples inhibited the tyrosinase, especially the sample from Prado that was most effective (124.62 μg.mL-1). Significant negative correlation was found between flavonoid contents and inhibition of tyrosinase. The overall results provide relevant information about the Dalbergia ecastaphyllum species, indicating as potential material to cosmetic and pharmaceutical industry.

Resumo -O objetivo deste trabalho foi selecionar o modelo de curvas de crescimento mais adequado e avaliar a influência de efeitos de ambiente e de grupo genético sobre os parâmetros estimados do modelo. Cinco modelos não lineares, Brody, Gompertz, Logístico, Von Bertalanffy e Richards, foram ajustados a dados de peso-idade coletados de 316 vacas, de quatro grupos genéticos: G (Nelore, ½Canchim + ½Nelore, ½Angus + ½Nelore e ½Simental + ½Nelore), do nascimento até 100 meses de idade; em duas estações do ano: E (primavera e outono). As vacas foram submetidas a dois níveis de concentrado (S) durante quatro meses, pós-desmama. O ajuste dos modelos foi realizado por mínimos quadrados ordinários, usando os pesos ponderado e não ponderado pelo inverso da variância. Os modelos Brody e Von Bertalanffy convergiram para todos os grupos genéticos; porém, o Brody foi o mais adequado. As estimativas do peso assintótico (A) e da taxa de maturação (k) do modelo Brody ponderado pelo inverso da variância foram analisadas por modelo misto, que incluiu efeito médio global e efeitos principais de G, E e S, e suas interações. O parâmetro A foi influenciado pelo efeito de G e E, enquanto k foi influenciado por S, o que indica que melhorias no manejo alimentar resultam em menor variação na forma das curvas de crescimento e em altas taxas de maturação.Termos para indexação: cruzamento, curvas de crescimento, heterocedasticidade, modelo Brody, suplementação alimentar, variância ponderada. Growth curves in beef cows of different biological typesAbstract -The objective of this study was to select the best growth curve model, and to evaluate the influence of environmental and genetic group effects on the estimated parameters of the model. Five nonlinear models, Brody, Gompertz, Logistic, Von Bertalanffy and Richards, were adjusted to age-weight data measured in 316 cows, obtained from four genetic groups: G (Nellore, ½Canchim + ½Nellore, ½Angus + ½Nellore, and ½Simmental + ½Nellore), from birth to 100 months of age; in two calving seasons: E (spring and fall). The cows were submitted to two levels of concentrate (S) during four months, after weaning. The models were adjusted by ordinary least squares using inverse-variance weighted and unweighted mass. The Brody and Von Bertalanffy models converged for all genetic groups; however, the Brody model had a better fit. Estimates for asymptotic weight (A) and maturing rate (k) of the weighted Brody model were analyzed by a mixed model, which included overall effect and fixed effects of G, E, and S, and respective interactions. Parameter A was influenced by the effects of G and E, while k was influenced by S, indicating that improvements in feeding management result in less variation in the shape of growth curves and in increased rates of maturity.Index terms: crossbreeding, growth curves, heteroscedasticity, Brody model, feed supplementation, weighted variance. IntroduçãoO crescimento corporal da maioria das espécies pode ser descrito por uma curva sigmoide e, portanto, ajustado por modelos não l...

O presente estudo buscou construir um instrumento de pesquisa de satisfação de alunos de um curso de educação superior e investigar a estrutura fatorial deste questionário. A coleta dos dados foi realizada por meio de um questionário fechado, baseado na escala Likert, com respostas variando em cinco níveis de satisfação. A amostra estratificada foi composta por 50 estudantes do Departamento de Estatística da Universidade Federal de Mato Grosso - UFMT. Foi utilizada a Análise Fatorial Exploratória, que sugeriu o agrupamento das 19 variáveis do questionário em quatro fatores distintos, que proporcionaram maior homogeneidade entre as variáveis dentro de cada grupo: Professores de outros departamentos que ministram aula aos alunos de Estatística, Instalações físicas e estruturais, Professores do Departamento de Estatística, e Desempenho do Aluno (Auto avaliação).O total dos fatores explicou100% da variação total, o primeiro fatorexplicou27%, o segundo, 26%, o terceiro, 24% e o quarto, 23%. Em pesquisas futuras poderá ser utilizado o novo questionário, organizado nas dimensões identificadas por meio da análise fatorial.