Massed and spaced training build up different components of long-term habituation in the crabChasmagnathus

The crabChasmagnathus granulatus reacts to a shadow passing overhead with an escape response that habituates after 30 trials and for 5 days at least. The effect of a wide range of different intertrial intervals (ITIs) (0, 9, 27, 45, 81, 135, and 171 sec) on theChasmagnathus long-term habituation (LTH) was evaluated at 24 h. Memory retention was estimated separately at two phases of a six-trial testing session: at first trial (the initial testing phase) and at the subsequent block of five trials (the retraining phase). A training of 30 trials with an ITI equal to or longer than 27 sec induced LTH at both testing phases, however, with a 0- or a 9-sec ITI, training wholly failed to build up LTH. When the number of trials was increased, a massed training (ITI=0 or 9 sec) induced LTH at retraining but not at initial testing. Thus, massed training produces LTH only at retraining, whereas spaced training (ITI ≥ 27 sec) produces LTH at both initial phase and retraining. An ITI shift from training to testing diminished or abolished retention at retraining regardless of the direction of the shift, thus suggesting that crabs acquire a memory of the trial-spacing at training. According to these results, it is postulated that LTH consists of two memory components: one produced by spaced training and expressed at both initial testing and retraining, and one yielded by massed training and expressed only at retraining. The possibility that the two components of LTH were differentially affected by cycloxemide and context shift is discussed.     

Parenting as a Protective Process for School Success in Children from Homeless Families

The role of parenting as a protective process for school success was investigated among 59 African American children 6 to 11 years old from homeless families residing in a Minneapolis shelter. Reliable scores for three dimensions of parenting—parent-child closeness, parent involvement in education, and firm discipline—were derived from ratings based on interviews with parents while they were living at the shelter. After families had left the shelter, children's school success was assessed via three types of indicators: a) performance on a standardized achievement test; b) ratings of school records for the current school semester as well as cumulative school records; and c) teacher assessments of appropriate school behavior. Results suggested that good parenting may be protective for school success in these children. Close parent-child relationships and high parent involvement in the child's education were associated with school success in terms of school records of achievement and behavior in school. Parent's intellectual functioning, education level, psychological distress and firm disciplinary practices were unrelated to child academic success. Future research directions and implications for intervention are discussed.     

Spiral and Project-Based Learning with Peer Assessment in a Computer Science Project Management Course

Different learning methods such as project-based learning, spiral learning and peer assessment have been implemented in science disciplines with different outcomes. This paper presents a proposal for a project management course in the context of a computer science degree. Our proposal combines three well-known methods: project-based learning, spiral learning and peer assessment. Namely, the course is articulated during a semester through the structured (progressive and incremental) development of a sequence of four projects, whose duration, scope and difficulty of management increase as the student gains theoretical and instrumental knowledge related to planning, monitoring and controlling projects. Moreover, the proposal is complemented using peer assessment. The proposal has already been implemented and validated for the last 3 years in two different universities. In the first year, project-based learning and spiral learning methods were combined. Such a combination was also employed in the other 2 years; but additionally, students had the opportunity to assess projects developed by university partners and by students of the other university. A total of 154 students have participated in the study. We obtain a gain in the quality of the subsequently projects derived from the spiral project-based learning. Moreover, this gain is significantly bigger when peer assessment is introduced. In addition, high-performance students take advantage of peer assessment from the first moment, whereas the improvement in poor-performance students is delayed.     

Cognitive Diversity in Middle-Aged and Elderly Adults: The Role of Education

This study examines cognitive diversity through performance of four attentional tasks and a vocabulary measure in relation to age and level of education. Tasks were performed by 168 participants (aged between 45 and 91 years) who were grouped according to age and level of education. Multivariate analyses of variance were applied to Z scores calculated from intersubject coefficients of variation. When the variance associated with education was discounted prior to analysis, a disproportionate increase in cognitive diversity was observed in participants over 75 years of age. When cognitive diversity was analyzed in relation to age and education in the three youngest age groups, participants with a low level of education displayed higher diversity in most attentional tasks from 66 years of age. In participants with a high level of education, diversity was lower for all attentional tasks considered from 56 years of age. Vocabulary knowledge was the most sensitive to education-related cognitive diversity. The diversifying effect of the relationship between education and diversity on fluid cognitive performance appeared to reverse and become a homogenizing effect with increasing age.     

Aerobic training but no resistance training increases SIRT3 in skeletal muscle of sedentary obese male adolescents

In recent years, prevalence of obesity in children and adolescents has increased. A strategy for prevention and management of obesity is aerobic training (AT) due to its effectiveness to decrease fat mass. AT increases the content of SIRT3, a mitochondrial protein that increases the expression of PGC-1α and NFR1, thereby enhances mitochondrial function and metabolic health. Resistance training (RT) provides metabolic benefits but its effect on SIRT3 content is unknown. To compare the effect of AT and RT on SIRT3, PGC-1α and NRF-1 protein levels in skeletal muscle of sedentary obese adolescents. Twenty-seven sedentary obese male adolescents (age: 16.7?±?0.9 years; BMI: 33.7?±?4.3?kg/m²) completed a 1-month control period prior to randomization to one of two supervised exercise protocols: AT (3 days/week, 40 min/day, 70–80% peak heart rate) or RT (3 days/week, 11 exercises, 2 sets/exercise, 12 repetitions/set) for 12 weeks. Biopsies were obtained from the vastus lateralis muscle before and after 12 weeks to analyse SIRT3, PGC-1α and NRF-1 proteins content. Peak oxygen consumption (VO_2peak) and anthropometric variables were evaluated before and after training. AT increased SIRT3 content, which was associated with improvements in PGC-1α content and body fat percentage. RT did not affect SIRT3 or PGC-1α. VO_2peak increased only in AT. The increase in muscle mitochondrial SIRT3 was observed only following AT. In contrast, RT increased muscle mass without improving SIRT3 in obese male adolescents.