Effect of 4 weeks of basic military training on peripheral blood leucocytes and urinary excretion of catecholamines and cortisol

In this study, we assessed the effects of a 4 week basic military physical training programme for male recruits of the Hellenic Air Force on the number and distribution of circulating immune cells and adrenergic and adrenocortical hormonal responses. One group of recruits (exercised, n = 48) participated in moderate intermittent physical exercise, whereas a second group (non-exercised controls, n = 9) performed only light work in the barracks. Both groups participated in the same non-physical, classroom-type training and testing. Military training by the exercised group resulted in significant increases in CD4^?+? T-lymphocytes, renal cortisol excretion and the urinary noradrenaline/adrenaline ratio, together with reductions in neutrophils and the neutrophil/lymphocyte ratio. In the exercised group, the urinary noradrenaline/adrenaline ratio correlated positively with the training-induced changes in CD4^?+? T-lymphocytes and negatively with changes in the neutrophil/lymphocyte ratio. No significant relationship was found between training-induced increases in cortisol excretion and any of the peripheral blood cell alterations. Our results indicate that 4 weeks of military training consisting of intermittent moderate exercise resulted in a significant increase in CD4^?+? T-lymphocytes and reduction in neutrophils. These changes were probably driven by alterations in hormonal status, including the significant impact of sympathetic nervous system activation.     

Active recovery intervals restore initial performance after repeated sprints in swimming*

The purpose of this study was to examine the effects of active recovery (AR) and passive recovery (PR) using short (2-min) and long (4-min) intervals on swimming performance. Twelve male competitive swimmers completed a progressively increasing speed test of 7?×?200-m swimming repetitions to locate the speed before the onset of curvilinear increase in blood lactate concentration (LT₁). Subsequently, performance time of 6?×?50-m sprints was recorded during four different conditions: (i) 2-min PR (PR-2), (ii) 4-min PR (PR-4), (iii) 2-min AR (AR-2) and (iv) 4-min AR (AR-4) intervals. Blood lactate concentration was measured before the first and after the last 50-m repetition. AR was applied at an intensity corresponding to LT₁. Performance as indicated by the time needed to complete 6?×?50-m sprints was impaired after AR-4 compared to PR-4 (AR-4: 28.65?±?1.04, PR-4: 28.17?±?0.72?s; mean% difference: MD% ±s; ±90% confidence limits: 90%CL, 1.71?±?3.01%; ±1.43%, p?=?.01) but was not different between AR-2 compared to PR-2 conditions (AR-2: 28.68?±?0.85, PR-2: 28.69?±?0.82 s; MD%: 0.03?±?1.61%; 90%CL?±?0.77%, p?=?.99). Performance in sprint-6 was improved after AR compared to PR independent of interval duration (AR: 28.55?±?0.81, PR: 29.01?±?1.03?s; MD%: 1.52?±?2.61%; 90%CL?±?1.2%; p?=?.03). Blood lactate concentration was lower after AR-4 compared to PR-4 but did not differ between AR-2 and PR-2 conditions. In conclusion, AR impaired performance after a 4-min but not after a 2-min interval. A better performance during sprint-6 after AR could be attributed to a faster metabolic recovery or anticipatory regulatory mechanisms towards the end of the series especially when adequate 4-min active recovery interval is applied.     

The acute effects of an intense stretch-shortening cycle fatigue protocol on the neuromechanical parameters of lower limbs in men and prepubescent boys

The study examined the differences between boys and adults after an intense stretch-shortening cycle fatigue protocol on neuromechanical parameters of the lower limb. Thirteen boys (9–11 years old) and 13 adult men (22–28 years old) were tested for maximal isometric voluntary knee extension torque and drop jump (DJ) performance from 30 cm before and immediately after a fatigue protocol, consisted of 10 × 10 maximum effort vertical jumps. Three-dimensional kinematics, kinetics and electromyographic (EMG) parameters of the lower extremities muscles were recorded during DJs before and after the fatigue test. The results indicated that reduction in maximal isometric torque and jumping performance was significantly higher in adults compared to boys. Vertical ground reaction forces, contact time and maximum knee flexion increased in a greater extend in adults than in boys. In addition, preactivation, EMG agonist activity, knee joint stiffness and stretch reflex decreased more in adults than in boys at all the examined phases of jumping tasks. It is concluded that employed fatigue protocol induced acute reduction in performance and altered motor control during jumping in both age groups. However, the differences in the level of fatigue between the 2 groups could be attributed to neuromuscular, mechanical and kinematic parameters observed between groups.     

A Cultural-Historical Study of the Development of Children’s Scientific Thinking about Clouds in Everyday Life

Research in Science Education - Research into early childhood children’s understandings in science has a long history. However, few studies have drawn upon cultural-historical theory to frame...     

Fictive kinship as it mediates learning, resiliency, perseverance, and social learning of inner-city high school students of color in a college physics class

In this hermeneutic study we explore how fictive kinship (kin-like close personal friendship) amongst high school students of color mediated their resiliency, perseverance, and success in a college physics class. These freely chosen, processual friendships were based on emotional and material support, motivation, and caring for each other, as well as trust, common interests, and goals. Such close bonds contributed in creating a safe and supportive emotional space and allowed for friendly, cooperative competition within the physics classroom. Friends became the role models, source of support, and motivation for the fictive kinship group as well as for each other, as the group became the role model, source of support, and motivation for the individuals in it. Because of their friendships with one another, physics talk was extended and made part of their personal interactions outside the classroom. These social relationships and safe spaces helped the students cope and persevere despite their initial conflicting expectations of their success in physics. Our research thus expands on the concept of social learning by exploring student friendships and how they frame and mediate such a process.     

Data-driven problem based learning: enhancing problem based learning with learning analytics

Educational technology research and development - Problem based learning (PBL) supports the development of transversal skills and could underpin the training of a workforce competent to withstand...     

Science Education in Kindergarten: Sociocognitive perspective

This article deals with the different didactic strategies used for the initiation of preschool children to the natural sciences. There is a reference to the general characteristics of the activities that are based either on the empiricist theoretical approach or the theory of Piaget regarding cognitive development. Some facts from the neo‐piagetian, socioconstructive and vygotskian perspectives for learning are presented. Within this framework a new sociocognitive approach is put forward for the development of activities concerning the natural sciences in the kindergarten. An activity concerning the understanding of gasification is presented and used as an example of the sociocognitive perspective.     

嵌入学习管理系统的基于词汇表的概念图应用程序

概念构图作为一种有价值的教学活动,有着非常稳固的理论框架作为支持,其在教育教学中的作用不容置疑.本文介绍了一个软件工具的开发,在该工具中,概念构图被当作一种重要的教学活动予以支持.该工具以课程词汇表为基础,被集成到一个学习管理系统中.该工具允许在词汇表中概念的详细描述和认知结构的知识表示之间切换.论文介绍了该应用程序的开发动机、合理性、特色及其应用.     

Anatomy Learning from Prosected Cadaveric Specimens Versus Plastic Models: A Comparative Study of Upper Limb Anatomy

Human cadaveric prosections are a traditional, effective, and highly appreciated modality of anatomy learning. Plastic models are an alternative teaching modality, though few studies examine their effectiveness in learning of upper limb musculoskeletal anatomy. The purpose of this study is to investigate which modality is associated with a better outcome, as assessed by students' performance on examinations. Overall, 60 undergraduate medical students without previous knowledge of anatomy participated in the study. Students were assigned into two groups. Group 1 attended lectures and studied from cadaveric prosections (n = 30) and Group 2 attended lectures and used plastic models in the laboratory (n = 30). A knowledge assessment, including examination with tag questions (spot test) and written multiple-choice questions, was held after the end of the study. Students' perceptions were also investigated via an anonymous questionnaire. No significant difference in students' performance was observed between the group using prosections and the group using plastic models (32.2 ± 14.7 vs 35.0 ± 14.8, respectively; P = 0.477). Similarly, no statistically significant difference was found regarding students' satisfaction from using each learning modality (P = 0.441). Plastic models may be a valuable supplementary modality in learning upper limb musculoskeletal anatomy, despite their limitations. Easy to use and with no need for maintaining facilities, they are highly appreciated by students and can be useful when preparing for the use of cadaveric specimens.