Enzymatically dissociated flexor digitorum brevis (FDB) and soleus fibres from mouse were used to compare the kinetics of electrically elicited Ca2+ transients of slow and fast skeletal muscle fibres, using the fast Ca2+ dye MagFluo4-AM, at 20-22 degrees C. For FDB two Ca2+ transient morphologies, types I (MT-I, 11 fibres, 19%) and II (MT-II, 47 fibres, 81%), were found, the kinetic parameters (amplitude, rise time, half width, decay time, and time constants of decay) being statistically different. For soleus (n = 20) only MT-I was found, with characteristics similar to MT-I from FDB. Correlations with histochemically determined mATPase, reduced nicotinamide adenine dinucleotide diaphorase and alpha-glycerophosphate dehydrogenase activities, as well as immunostaining and myosin heavy chain electrophoretic analysis of both muscles suggest that signals classified as MT-I may correspond to slow type I and fast IIA fibres while those classified as MT-II may correspond to fast IIX/D fibres. The results point to the importance of Ca2+ signaling for characterization of muscle fibres, but also to its possible role in determining fibre function.

The isonymy structure of Buenos Aires was studied based on its surname frequency. Information on 2,552,359 voters of the 28 Buenos Aires districts was used to estimate Lasker's coefficient of relationship by isonymy (R(i)), surname diversity according to Fisher's alpha, the coefficient of consanguinity resulting from random isonymy (F), and Nei's, Lasker's and the Euclidean isonymy distances. These distances were correlated with geographic distances, which were calculated by assigning an arbitrary point to each district and measuring distances on a map of the city. The R(i) x 10(5) and F x 10(4) averages of the districts located south of Rivadavia Avenue were higher (R(i) = 66.08; F = 3.4) than those situated north of that avenue (R(i) = 46.60; F = 2.4) (p < 0.001). Fisher's alpha showed the opposite behavior (north, alpha = 1,055.5; south, alpha = 757.2). There was a significant correlation (p < 0.001) between geographic distance and Nei's and the Euclidean distances (0.496 and 0.503, respectively), but the correlation was not significant for Lasker's distance (0.051). These results indicate isolation by distance in the city of Buenos Aires and reveal subdivision of the metropolitan population, with greater consanguinity and a lesser variety of surnames in the districts located in the southern section of the city. This structure agrees with the fragmentation and social, cultural, and economic differences observed among the districts of this Latin American metropolis.

(i) All systems were in Hardy-Weinberg equilibrium, except the Rh blood group of the Central-Western Region; (ii) the European contribution is high in both groups; (iii) in the dendrogram and PCA, the studied populations appear close to other admixed populations, and their relative position with regard to the three parental populations coincides with the admixture analysis.

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Life conditions are key factors for defining growth and development of future generations. Exposure of parents to alcohol, tobacco, food insecurity conditions and adverse socioeconomic environment as part of their lifestyle and quality of life, have been reported to affect their children’s health and wellbeing. Prenatal exposures have been extensively documented, but less is known about influences from parental harmful habits and disadvantaged environment during children‘s school years. The aim of this study is to examine potential associations between parental habits and environmental socioeconomic conditions, including food security status, and anthropometric characteristics of their children. Parental smoking, alcohol intake, food security, and socioeconomic status (SES) were explored in parents of 1730 children recruited at private and public schools in eight Venezuelan cities. These qualitative variables were collected through a semi-structured questionnaire. Weight, height and body mass index were measured using standardized methods in children. Height and BMI were converted to z-scores according to WHO international growth reference. Low BMI z-scores in children were significantly associated with mothers consuming alcohol. The frequency of children with short height was higher in households with impaired access to quality foods and where mothers reported low and very low food security status. In brief, our study indicates that social environment could have detrimental effects on child anthropometry thus, affecting their wellbeing.