Measurement error in short-term power testing in young people

The aim of this study was to examine the consistency or reproducibility of measuring cycling peak power in children and adults. Twenty-seven pre-pubertal girls and boys and 27 female and male physical education students (age 9.8±0.5 and 24.4±4.3 years, respectively; mean±s) participated in the study. All participants performed five tests over 15 days and underwent a habituation session before the study. Each test included four sprints against four different braking forces. We found that braking forces of 7.5% of body weight in children and 10% of body weight in adults were too high for most of the participants to elicit maximal cycling power. Unlike the children, the physical education students improved their performance between session 1 and session 2 (1025±219 vs 1069±243 W; P<0.001). Therefore, to obtain reproducible measures of cycling peak power, a habituation session including a complete test protocol (i.e. warm-up plus three sprints) is highly recommended. When the protocol included three sprints in children and at least two sprints in adults, measurement of cycling peak power was found to be highly reliable (test-retest coefficient of variation ～3%). Finally, to avoid performance fluctuations, especially over several consecutive evaluations (e.g. longitudinal studies), it is necessary to maintain high motivation in children.     

An investigation into the emotional reactions to inclusion of Ghanaian mainstream teachers

Literature is replete with evidence of considerable pressure that many mainstream teachers may experience in their bid to respond to the diverse needs of children with special educational needs and disabilities and to achieve ever better results. In this study, the results of 100 teachers from mainstream primary schools in three of the ten regions of Ghana were examined. The analysis involved five bi‐polar emotional reactions; namely: anxious/relaxed; encouraged/discouraged; confident/diffident; satisfied/dissatisfied; self‐assured/ worried. The results confirmed that in teaching children with SEN in the mainstream, teachers experienced psychological stress. On the basis of the findings, suggestions for more information about SEN, supply of resources and inter‐agency collaboration were made.     

分布式光伏发电系统中的微逆变器技术研究

微逆变器可实现独立的光伏模组最大功率点追踪控制,极大优化并网光伏发电系统的光伏能量转换,提供即插即用概念。光伏微逆变器在功率变换中,常采用高频变压器升压产生期望的输出交流电压,根据直流链配置可以分为直流链、伪直流链和无直流链3种微逆变器拓扑结构。微逆变器控制技术包括最大功率点追踪控制技术、输出电流控制技术、孤岛效应侦测与保证技术等,且功率开关对于改善微逆变器的转换效率至关重要。     

Funding of Libraries in Nigeria: The Way Forward

The main focus of this paper is the funding of libraries in Nigeria. The sources of funds for libraries, which include the government, grants, donations and bequests, are discussed. The factors affecting the funding of libraries in Nigeria are highlighted. Finally, alternative sources for funding are also discussed.