Effects of blood flow restriction without additional exercise on strength reductions and muscular atrophy following immobilization:A systematic review

Purpose:To investigate whether blood flow restriction(BFR) without concomitant exercise mitigated strength reduction and atrophy of thigh muscles in subjects under immobilization for lower limbs.Methods:The following databases were searched:PubMed,CINAHL,PEDro,Web of Science,Central,and Scopus.Results:The search identified 3 eligible studies,and the total sample in the identified studies consisted of 38 participants.Isokinetic and isometric torque of the knee flexors and extensors was examined in 2 studies.Cross-sectional area of thigh muscles was evaluated in 1 study,and thigh girth was measured in 2 studies.The BFR protocol was 5 sets of 5 min of occlusion and 3 min of free flow,twice daily for approximately 2 weeks.As a whole,the included studies indicate that BFR without exercise is able to minimize strength reduction and muscular atrophy after immobilization.It is crucial to emphasize,however,that the included studies showed a high risk of bias,especially regarding allocation concealment,blinding of outcome assessment,intention-to-treat analyses,and group similarity at baseline.Conclusion:Although potentially useful,the high risk of bias presented by original stodies limits the indication of BFR without concomitant exercise as an effective countermeasure against strength reduction and atrophy mediated by immobilization.     

Behavior and emotional problems among Jamaican children and adolescents: an epidemiological survey of parent, teacher, and self-reports for ages 6–18 years

The study compared general population samples of Jamaican children ages 6–18 years, via Jamaican versions of the Child Behavior Checklist (CBCL) parent-, teacher-, and self-report forms. Repeated measures ANOVAs with informant as a repeated measures factor, assessed base-rate problem score differences according to children’s area of residence (i.e., urban vs rural), gender, and age. No between subjects residence effects emerged for total problem score. However, adolescents self-reported higher total problem scores compared to the ratings they received from their parents and teachers. No gender total problem score effects emerged for any of the three informants, but girls received higher internalizing, and Somatic Complaints scores. Similar total problem scores across genders, and the high ratio of boys to girls in clinic samples suggest that Jamaican girls may not be receiving adequate services. Age X within subjects interactions revealed higher teacher reported problem scores for young adolescents, reflecting possible developmental changes within the classroom context and teachers’ low thresholds toward these problems. The d statistic revealed base rate syndrome, internalizing, externalizing, and total problem score differences in most Jamaican vs US sub-samples. In addition to the non-CBCL problems observed in earlier studies, these findings clearly indicate a need to ascertain syndrome structure and other psychometric properties of the Jamaican instruments.     

A cognitive analysis of Cauchy’s conceptions of function,continuity, limit and infinitesimal,with implications for teaching the calculus

In this paper, we use theoretical frameworks from mathematics education and cognitive psychology to analyse Cauchy’s ideas of function, continuity, limit and infinitesimal expressed in his Cours D’Analyse. Our analysis focuses on the development of mathematical thinking from human perception and action into more sophisticated forms of reasoning and proof, offering different insights from those afforded by historical or mathematical analyses. It highlights the conceptual power of Cauchy’s vision and the fundamental change involved in passing from the dynamic variability of the calculus to the modern set-theoretic formulation of mathematical analysis. This offers a re-evaluation of the relationship between the natural geometry and algebra of elementary calculus that continues to be used in applied mathematics, and the formal set theory of mathematical analysis that develops in pure mathematics and evolves into the logical development of non-standard analysis using infinitesimal concepts. It suggests that educational theories developed to evaluate student learning are themselves based on the conceptions of the experts who formulate them. It encourages us to reflect on the principles that we use to analyse the developing mathematical thinking of students, and to make an effort to understand the rationale of differing theoretical viewpoints.