A Review of the Brazilian NBR 15575 Standard: Applying the Simulation and Simplified Methods for Evaluating a Social House Thermal Performance

The new Brazilian ABNT NBR 15575 Standard (the ―Standard‖) recommends two methods for analyzing housing thermal performance: a simplified and a computational simulation method. The aim of this paper is to evaluate both methods and the coherence between each. For this, the thermal performance of a low-cost single-family house was evaluated through the application of the procedures prescribed by the Standard. To accomplish this study, the EnergyPlus software was selected. Comparative analyses of the house with varying envelope U-values and solar absorptance of external walls were performed in order to evaluate the influence of these parameters on the results. The results have shown limitations in the current Standard computational simulation method, due to different aspects: weather files, lack of consideration of passive strategies, and inconsistency with the simplified method. Therefore, this research indicates that there are some aspects to be improved in this Standard, so it could better represent the real thermal performance of social housing in Brazil.

Factors associated with overweight in children living in the neighbourhoods of an urban area of Brazil

Objective: The present study aimed to investigate the individual and family determinants of being overweight among children younger than 10 years of age. Design: Cross-sectional survey. Direct data on children's age, food intake, physical activity, type of transportation used and anthropometric measurements, as well as the education level of the mothers, were collected by trained interviewers. Setting: Population-based study in the city of Santos, Brazil. Subjects: A total of 531 children under 10 years of age (302 aged <6 years, >= 6 aged years), living in the city of Santos. Results: The overall prevalence of overweight and obesity (BMI-for-age Z-score >1) was 35.4% for children under 6 years and 38.9% for children aged 6-10 years. The socio-economic status of the family was associated with being overweight for both age groups. Logistic regression analysis showed that the lower the socio-economic status, the higher the likelihood of being overweight, among both younger children (OR = 7.73; P = 0.02) and older children (OR = 1.98; P = 0.04). The use of active transportation was associated with a lower likelihood of being overweight, but only among younger children (OR = 1.70; P = 0.05). Conclusions: Socio-economic status seems to be an important individual-level determinant of overweight in children. Public policies should consider promoting the use of active transportation, as the results showed it to have a positive effect on reducing overweight issues. The high prevalence of overweight in younger children suggests that this age group should be a priority in health-promoting interventions.

Differentiation of African Components of Ancestry to Stratify Groups in a Case-Control Study of a Brazilian Urban Population

Background: Balancing the subject composition of case and control groups to create homogenous ancestries between each group is essential for medical association studies. Methods: We explored the applicability of single-tube 34-plex ancestry informative markers (AIM) single nucleotide polymorphisms (SNPs) to estimate the African Component of Ancestry (ACA) to design a future case-control association study of a Brazilian urban sample. Results: One hundred eighty individuals (107 case group; 73 control group) self-described as white, brown-intermediate or black were selected. The proportions of the relative contribution of a variable number of ancestral population components were similar between case and control groups. Moreover, the case and control groups demonstrated similar distributions for ACA <0.25 and >0.50 categories. Notably a high number of outlier values (23 samples) were observed among individuals with ACA <0.25. These individuals presented a high probability of Native American and East Asian ancestral components; however, no individuals originally giving these self-described ancestries were observed in this study. Conclusions: The strategy proposed for the assessment of ancestry and adjustment of case and control groups for an association study is an important step for the proper construction of the study, particularly when subjects are taken from a complex urban population. This can be achieved using a straight forward multiplexed AIM-SNPs assay of highly discriminatory ancestry markers.

Nutritional transition of school children from low income families of a northeastern urban area, Brazil

Background: Evaluating child growth is, in practice, performed by measuring the development of a child's weight, height, and body composition in comparison to averages observed among a reference population. Objective: To describe the nutritional status of children of low income families who live in urban region in northeastern Brazil. Methods: This study is a population case series with a transversal and observational design. The study population consisted of 257 children, aged 5 to 10 years, who were enrolled in a public school to children of low income families. We used the cutoff point for short stature of -2 Z scores for age, and underweight, overweight, and obese were classified as the 5th, 85th, and 95th percentiles, respectively, of the body mass index (BMI) for age, with both classifications in accordance with the Center for Disease Control and Prevention (CDC 2000). Comparisons by gender were performed for the measures of the central tendency and the frequency of diagnoses, in addition to the tendency of the evolution of BMI by age. Results: The prevalence of short stature was 3.5% (95% CI: 1.9-6.5). In the evaluation of BMI for age, the prevalences found for underweight, overweight, and obese were 5.8% (95% CI: 3.6-9.4), 4.7% (95% CI: 2.7-8.0), and 2.3% (95% CI: 1.1-5.0), respectively. We found a significant trend in the reduction of BMI with the increase in age. Conclusions: According to CDC references, the prevalences of underweight and short stature were higher than expected and for the overweight and obesity were lower than expected, indicating that the nutritional transition had still not reached, as commonly is described, these low income children from the urban outskirts of the Northeast region.

Rehabilitation with forage grasses of an area degraded by urban solid waste deposits

Dry matter yield and chemical composition of forage grasses harvested from an area degraded by urban solid waste deposits were evaluated. A split-plot scheme in a randomized block design with four replicates was used, with five grasses in the plots and three harvests in the subplots. The mineral content and extraction and heavy metal concentration were evaluated in the second cut, using a randomized block design with five grasses and four replicates. The grasses were Brachiaria decumbens cv. Basilisk, Brachiaria ruziziensis, Brachiaria brizantha cv. Marandu and cv. Xaraés, and Panicum maximum cv. Tanzânia, cut at 42 days of regrowth. The dry matter yield per cut reached 1,480 kg ha-1; the minimum crude protein content was 9.5% and the average neutral detergent fiber content was 62.3%. The dry matter yield of grasses was satisfactory, and may be an alternative for rehabilitating areas degraded by solid waste deposits. The concentration of heavy metals in the plants was below toxicity levels; the chemical composition was appropriate, except for phosphorus. The rehabilitated areas may therefore be used for grazing.