Bias in the prediction of genetic gain due to mass and half-sib selection in random mating populations

The prediction of gains from selection allows the comparison of breeding methods and selection strategies, although these estimates may be biased. The objective of this study was to investigate the extent of such bias in predicting genetic gain. For this, we simulated 10 cycles of a hypothetical breeding program that involved seven traits, three population classes, three experimental conditions and two breeding methods (mass and half-sib selection). Each combination of trait, population, heritability, method and cycle was repeated 10 times. The predicted gains were biased, even when the genetic parameters were estimated without error. Gain from selection in both genders is twice the gain from selection in a single gender only in the absence of dominance. The use of genotypic variance or broad sense heritability in the predictions represented an additional source of bias. Predictions based on additive variance and narrow sense heritability were equivalent, as were predictions based on genotypic variance and broad sense heritability. The predictions based on mass and family selection were suitable for comparing selection strategies, whereas those based on selection within progenies showed the largest bias and lower association with the realized gain

Epidemiological study of traumatic dental injuries in 5- to 6-year-old Brazilian children

Monitoring traumatic dental injury (TDI) in primary teeth through epidemiological cross-sectional surveys provides descriptive information relevant to the development of public policies focused on the prevention of such injuries for the target population. The aim of this study was to assess the prevalence of TDI in 5- to 6-year-old Brazilian children and its association with biological and socioeconomic factors. A total of 684 children aged 5 to 6 years old, from 11 public schools in the city of Barueri (Brazil) were evaluated. Clinical examinations were carried out in the schools, by two trained and calibrated examiners. Gauze and a mouth mirror were used for the examinations. The reported TDIs were classified according to the Andreasen (2007) criteria for primary teeth. The results showed that 52.3% of the children had TDI. Enamel fracture (63.4%) was the most frequently observed sign of TDI, and the most affected teeth were the primary maxillary central incisors (26.9% maxillary right central incisor and 24% maxillary left central incisor). There was no association between the presence of TDI and biological or socioeconomic factors. In conclusion, the prevalence of TDI was high and had no statistically significant association with biological and socioeconomic factors

First report of Rhodnius montenegrensis (Hemiptera, Reduviidae, Triatominae) in the State of Acre, Brazil

INTRODUCTION: This paper reports, for the first time, the presence of Rhodnius montenegrensis in the State of Acre, Brazil. METHODS: Two female R. montenegrensis were collected in a dwelling in the rural area of Rio Branco, Acre, Brazil. RESULTS: The occurrence of this species was confirmed, and the number of Triatominae species in the State of Acre increased from four to five. CONCLUSIONS: Further studies should be performed to reach a clearer understanding of the ecology of this arthropod, its possible role in transmitting Chagas' disease and rangeliosis, and its current geographical distribution in the region