Skipping breakfast,sedentarism and overweight in children

To show by use of path analysis how in children of 9 and 10 years of age the known relationship between breakfast and high body mass index (BMI) is mediated by sedentary leisure time activities. A random sample of 291 9-year-old and 10-year-old school children from the Principality of Asturias (Spain) was taken. A transversal design was used, their weight and height were measured and an individual standardized interview was carried out in which they were asked about their breakfast habits and the time they spent each week on sedentary leisure activities. Using path analysis, a model was tested in which breakfast habits and leisure time were the independent variables and the BMI was the dependent variable. The results showed that there was an inverse correlation between number of breakfasts and BMI and a direct correlation between the time spent on sedentary leisure activities and BMI. Path analysis showed that the relationship between the frequency with which breakfast was eaten and BMI was mediated by the time spent on sedentary leisure activities. The above appears to confirm the direct role played by failing to have breakfast in the pandemic of obesity as this habit tends to increase children’s BMI. This relationship is, however, mediated by sedentary leisure. According to the data compiled, being overweight in children can only be prevented by modifying not just one of the habits that have been associated with it, but rather the whole group of habits as these appear to make up an obesogenic cluster in which sedentary leisure and not having breakfast are included.     

Effects of role model exposure on STEM and non‐STEM student engagement

Studies examining factors (e.g., STEM stereotypes) that underlie the recruitment and retention of STEM students are critical as the demand for STEM professionals is rapidly increasing. This experimental study tested the effects of role model biographies that challenge common STEM stereotypes (i.e., STEM is for gifted individuals and for European American males) on 1035 STEM and non‐STEM undergraduate students. Findings showed that role model exposure had positive effects on both STEM and non‐STEM students’ interest in STEM as well as their perceived identity compatibility between the self and STEM. Role model exposure had a positive impact on academic sense of belonging among STEM and non‐STEM students, and a positive impact on academic self‐efficacy among STEM students, but not non‐STEM students.     

Activity-Dependent Activation of TrkB Neurotrophin Receptors in the Adult CNS

In this paper we have investigated the hypothesis that neural activity causes rapid activation of TrkB neurotrophin receptors in the adult mammalian CNS. These studies demonstrate that kainic acid-induced seizures led to a rapid and transient activation of TrkB receptors in the cortex. Subcellular fractionation demonstrated that these activated Trk receptors were preferentially enriched in the synaptosomal membrane fraction that also contained postsynaptic glutamate receptors. The fast activation of synaptic TrkB receptors could be duplicated in isolated cortical synaptosomes with KCl, presumably as a consequence of depolarization-induced BDNF release. Importantly, TrkB activation was also observed following pharmacological activation of brain-stem noradrenergic neurons, which synthesize and anterogradely transport BDNF; treatment with yohimbine led to activation of cortical TrkB receptors within 30 min. Pharmacological blockade of the postsynaptic α1-adrenergic receptors with prazosin only partially inhibited this effect, suggesting that the TrkB activation was partially due to a direct effect on postsynaptic cortical neurons. Together, these data support the hypothesis that activity causes release of BDNF from presynaptic terminals, resulting in a rapid activation of postsynaptic TrkB receptors. This activity-dependent TrkB activation could play a major role in morphological growth and remodelling in both the developing and mature nervous systems.     

Communication in relationships and adolescent substance use: the influence of parents and friends

This study focused on the openness of communication in teenagers' relationships with mother, father (or parental figure), and closest friend, and its correlation with teenagers' use of cigarettes, alcohol, marijuana, and other drugs. The predictive value for substance use of perceived pressure from friends, friends' substance use, and parents' substance use was also analyzed. The findings from questionnaires and interviews conducted with 37 students at an urban and a suburban/rural high school in New England are reported. The results suggest that the degree to which adolescents talk openly with their parents may influence the extent of their substance use. The presence of at least one "open" parental figure was associated with lower levels of all substance use. However, there was no evidence that openness with a close friend or perceived pressure from friends is related to substance use.     

Physical activity, sedentary leisure, short sleeping and childhood overweight

In this study, using the path analysis, the relation between physical activity, non-regulated activity, sedentary leisure, hours of sleeping, and the body mass index (BMI) was analyzed. The sample was made up of 103 students, 59 girls and 44 boys, aged between 9 and 10 1/2 years. An individual interview was performed in which the children were asked about the TV programs they watched each day of the week; the time they played with the console and the computer; the time dedicated to sports, games and other activities. The results showed that sedentary leisure (number of hours of TV, computer and console) maintains a significant and inverse relation with the hours of sleeping, non-regulated activity (games and others activities), and physical sport activity. The difference between the results of this study and the previous one is discussed, taking into account the recruitment procedure of the participants.