Social organization of marine Tucuxi dolphins, Sotalia guianensis, in the Cananeia Estuary of southeastern Brazil

Social organization is an important component of the population biology of a species that influences gene flow, the spatial pattern and scale of movements, and the effects of predation or exploitation by humans. An important element of social structure in mammals is group fidelity, which can be quantified through association indices. To describe the social organization of marine tucuxi dolphins (Sotalia guianensis) found in the Cananeia estuary, southeastern Brazil, association indices were applied to photo-identification data to characterize the temporal stability of relationships among members of this population. Eighty-seven days of fieldwork were conducted from May 2000 to July 2003, resulting in direct observations of 374 distinct groups. A total of 138 dolphins were identified on 1-38 distinct field days. Lone dolphins were rarely seen, whereas groups were composed of up to 60 individuals (mean +/- 1 SD = 12.4 +/- 11.4 individuals per group). A total of 29,327 photographs were analyzed, of which 6,312 (21.5%) were considered useful for identifying individuals. Half-weight and simple ratio indices were used to investigate associations among S. guianensis as revealed by the entire data set, data from the core study site, and data from groups composed of <= 10 individuals. Monte Carlo methods indicated that only 3 (9.3%) of 32 association matrices differed significantly from expectations based on random association. Thus, our study suggests that stable associations are not characteristic of S. guianensis in the Cananeia estuary.

Guiana dolphins (Sotalia guianensis) displaying beach hunting behavior in the Cananéia Estuary, Brazil: social context and conservation issues

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fractal scaling exponents of heart rate variability association with linear indices and Poincaré Plot

The literature indicated that the fractal analysis of heart rate variability (HRV) is related to the chaos theory. However, it is not clear if the both short and long-term fractal scaling exponents of HRV are reliable for short period analysis in women. We evaluated the association of the fractal exponents of HRV with the time and frequency domain and geometric indices of HRV. We evaluated 65 healthy women between 18 and 30 years old. HRV was analyzed with a minimal number of 256 RR intervals in the time (SDNN, RMSSD, NN50 and pNN50) and frequency (LF, HF and LF/HF ratio) domains, the geometric index were also analyzed (triangular indexRRtri, triangular interpolation of RR intervals-TINN and Poincaré plot-SD1, SD2 and SD1/SD2) as well as short and long-term fractal exponents (alpha-1 and alpha-2) of the detrended fluctuation analysis (DFA). No significant correlation was observed for alpha-2 exponent with all indices. There was significant correlation of the alpha-1 exponent with RMSSD, pNN50, SDNN/RMSSD, LF (nu), HF (nu and ms2 ), LF/HF ratio, SD1 and SD1/SD2 ratio. Our data does not indicate the alpha-2 exponent to be used for 256 RR intervals and we support the alpha-1 exponent to be used for HRV analysis in this condition.

Association between hypervolemia and ventricular hypertrophy in hemodialysis patients

Background: Left ventricular hypertrophy (LVH) is a well-known predictor of cardiovascular mortality in patients who have end-stage renal disease and are maintained on hemodialysis (HD), and LVH is not always correlated with the severity of hypertension in these patients. The purpose of this study was to investigate the role of other factors contributing to LVH.Methods: A total of 50 patients with HD were classified in three groups according to whether their LV mass index (LVMI) was higher than (n = 15), equal to (n = 20), or lower than (n = 15) that predicted by a formula based on their ambulatory blood pressure monitoring (ABPM).Results: Subjects with higher LVMI than predicted had significantly greater inter-HD weight gain (3.4 +/- 0.8 v 2.7 +/- 0.8 and 2.6 +/- 05 kg, respectively, in the other two groups, P < .05), and subjects with lower LVMI than predicted had a tendency toward a more pronounced nocturnal dipping pattern of BP (P = .07 v the other two groups), although daytime and night-time average BP levels did not differ between groups. All other clinical and laboratory parameters were similar among the three groups except higher cardiac output and various indices of LVH, which were more pronounced in the group with higher LVMI by ABPM. This group had also the lowest survival rate over the 2 to 3 years of follow-up, with five deaths versus two in each of the other two groups.Conclusions: the data suggest that correct management of inter-HD weight gain by nutritional counseling and shorter inter-HD intervals may prevent LVH and improve survival independently of BP control. (C) 2004 American Journal of Hypertension, Ltd.

Caries and its association with infant feeding and oral health-related behaviours in 3-4-year-old Brazilian children

Objectives: To investigate the relationships between socio-demographic factors, infant feeding habits, oral hygiene and the prevalence and patterns of caries in Brazilian 3-4-year-olds. Methods: Systematic random sampling was used to select children enrolled in municipal nurseries in Araraquara, Brazil, in 1998. Clinical examinations were carried out by one examiner using dmft and dmfs indices and WHO criteria. Questionnaires for information related to the socio-demographic background, oral hygiene and dietary history of the children were completed by their mothers. Results: Caries was seen in 46% of the children; 17% of them had the more extensive pattern involving molars and incisors. Social class, mother's education, and age at which breast-feeding terminated showed statistically significant associations with caries. Feeding bottles with added sugars were still being given to 80% of the children. When the significant variables were taken into account only age at which breast-feeding terminated showed a significant relationship to the pattern of disease. Children who were never breast-fed or were breast-fed beyond the age of 24 months had a higher prevalence of the more extensive pattern of caries. Conclusions: The association between the length of time a mother breast-feeds and extensive caries should be a consideration in any local infant feeding policies or health promotion strategies. The duration for appropriate breast- or bottle-feeding should be emphasised.

Analysis of genetic correlations of hip height with selection indices and mature weight in Nelore cattle

Body size is directly related to the productive and reproductive performance of beef cattle raised under free-range conditions. In an attempt to better plan selection criteria, avoiding extremes in body size, this study estimated the heritabilities and genetic correlations of yearling hip height (YH) and mature hip height (MH) with selection indices obtained at weaning (WI) and yearling (YI) and mature weight (MW). Data from 102,373 Nelore animals born between 1984 and 2010, which belong to 263 farms that participate in genetic evaluation programmes of beef cattle conducted in Brazil and Paraguay, were used. The (co)variance components and genetic parameters were estimated by Bayesian inference in multi-trait analysis using an animal model. The mean heritabilities for YH, MH and MW were 0. 56 ± 0. 06, 0. 47 ± 0. 02 and 0. 42 ± 0. 02, respectively. The genetic correlation of YH with WI (0. 13 ± 0. 01) and YI (0. 11 ± 0. 01) was practically zero, whereas a higher correlation was observed with MW (0. 22 ± 0. 03). Positive genetic correlations of medium magnitude were estimated between MH and WI and YI (0. 23 ± 0. 01 and 0. 43 ± 0. 02, respectively). On the other hand, a high genetic correlation (0. 68 ± 0. 03) was observed between the indicator traits of mature body size (MH and MW). Considering the top 20 % of sire (896 sires) in terms of breeding values for the yearling index, the rank sire correlations between breeding values for MH and MW was 0. 62. In general, the results indicate that selection based on WI and YI should not lead to important changes in YH. However, an undesired correlated response in mature cow height is expected, particularly when selection is performed using YI. Therefore, changes in the body structure of Nelore females can be obtained when MH and MW is used as a selection criterion for cows. © 2012 Institute of Plant Genetics, Polish Academy of Sciences, Poznan.

Estimates of genetic parameters and eigenvector indices for milk production of Holstein cows

The objectives of the present study were to estimate genetic parameters of monthly test-day milk yield (TDMY) of the first lactation of Brazilian Holstein cows using random regression (RR), and to compare the genetic gains for milk production and persistency, derived from RR models, using eigenvector indices and selection indices that did not consider eigenvectors. The data set contained monthly TDMY of 3,543 first lactations of Brazilian Holstein cows calving between 1994 and 2011. The RR model included the fixed effect of the contemporary group (herd-month-year of test days), the covariate calving age (linear and quadratic effects), and a fourth-order regression on Legendre orthogonal polynomials of days in milk (DIM) to model the population-based mean curve. Additive genetic and nongenetic animal effects were fit as RR with 4 classes of residual variance random effect. Eigenvector indices based on the additive genetic RR covariance matrix were used to evaluate the genetic gains of milk yield and persistency compared with the traditional selection index (selection index based on breeding values of milk yield until 305 DIM). The heritability estimates for monthly TDMY ranged from 0.12 ± 0.04 to 0.31 ± 0.04. The estimates of additive genetic and nongenetic animal effects correlation were close to 1 at adjacent monthly TDMY, with a tendency to diminish as the time between DIM classes increased. The first eigenvector was related to the increase of the genetic response of the milk yield and the second eigenvector was related to the increase of the genetic gains of the persistency but it contributed to decrease the genetic gains for total milk yield. Therefore, using this eigenvector to improve persistency will not contribute to change the shape of genetic curve pattern. If the breeding goal is to improve milk production and persistency, complete sequential eigenvector indices (selection indices composite with all eigenvectors) could be used with higher economic values for persistency. However, if the breeding goal is to improve only milk yield, the traditional selection index is indicated. © 2013 American Dairy Science Association.

Vocal complaint in physical education teachers and its association with the cardiovascular system

Background: We examined the vocal complaints and evaluated the correlation between the vocal handicap index (VHI) and heart rate variability (HRV) in physical education teachers. We evaluated 46 teachers. Method: The subjects were investigated regarding voice complaint and the VHI was applied. HRV was recorded at seated rest for ten minutes and it was analyzed in the time, frequency domains, geometric indices and fractal exponents. The three domains of the VHI were correlated with the indices of HRV. Results: The physical education teachers presented a VHI score much below the standard of the physiological normality. There was correlation of the organic domain of the VHI with the NN50 and pNN50 and correlation of the functional domain and organic domain of the VHI with the HF index of HRV. Conclusion: The physical education teachers evaluated reported vocal complaints that affected their function and it is suggested to be related with the cardiac autonomic regulation.