Reliability of unipodal and bipodal counter movement jump landings in a recreational male population

Movement patterns during landing have been suggested to be related to injury risk. The purpose of this study was to determine the inter-session reliability of kinematic variables and ground reaction forces during landing in a population of male recreational athletes after a counter movement jump. Both unipodal and bipodal landings were evaluated. Furthermore, the possibility to improve landing reliability with a verbal instruction was also studied. Twenty-four male volunteers with no history of lower extremity trauma were randomly assigned to two groups (with and without verbal landing instruction). An optoelectronic 3D system and force plates were used to measure the lower limb joint angles and the ground reaction forces during landing. Intraclass correlation values show moderate to excellent inter-session reliability for the bipodal task (ICC average: 0.80, range: 0.46–0.97) and poor to excellent reliability for the unipodal task (ICC average: >0.75, range: 0.20–0.95). However, large standard errors of measurement values at the ankle joint at impact (27.6?±?11.5°) and for the vertical ground reaction forces (394?±?1091 N) show that some variables may not be usable in practice. The verbal instruction had a negative effect on the reliability of unipodal landing but improved the reliability of bipodal landing. These findings show that the reliability of a landing task is influenced by its motor complexity as well as the instruction given to the subject.     

Learning science content through socio-scientific issues-based instruction: a multi-level assessment study

Science educators have presented numerous conceptual and theoretical arguments in favor of teaching science through the exploration of socio-scientific issues (SSI). However, the empirical knowledge base regarding the extent to which SSI-based instruction supports student learning of science content is limited both in terms of the number of studies that have been conducted in this area and the quality of research. This research sought to answer two questions: (1) To what extent does SSI-based instruction support student learning of science content? and (2) How do assessments at variable distances from the curriculum reveal patterns of learning associated with SSI-based instruction? Sixty-nine secondary students taught by three teachers participated in the study. Three teachers implemented an SSI intervention focused on the use of biotechnology for identifying and treating sexually transmitted diseases. We found that students demonstrated statistically and practically significant gains in content knowledge as measured by both proximal and distal assessments. These findings support the claim that SSI-based teaching can foster content learning and improved performance on high-stakes tests.     

电子商务实验课程的设计

对电子商务实验的开设问题提出以课程需要、应用需要以及以基本技能训练和学生创造性能力培养两方面切入实验内容的安排 ,并提供了一个实验安排的样本     

关于反腐败斗争的几点思考

腐败的表现是多方面的。主要表现在经济活动、组织人事、执纪执法、生活作风、结交朋友、亲属管理等方面。产生腐败的原因是复杂的 ,主要有攀比心理、侥幸心理、从众心理、拜金心理。我们应采取加强教育、依靠法制、搞好监督等措施 ,将反腐败斗争进行到底。     

Cultural Orientation Trajectories and Substance Use: Findings From a Longitudinal Study of Mexican‐Origin Youth

Cultural adaptation may influence Latino youth substance use (SU) development, yet few longitudinal studies have examined cultural change over time and adolescent SU outcomes. Using longitudinal data collected annually across ages 10–16 from 674 Mexican‐origin youth (50% female), the authors characterized cultural adaptation patterns for language use (English and Spanish use), values (American values and familism values), and identity (ethnic pride), and examined whether these cultural adaptation patterns were associated with differential SU risk. Youth with increasing bilingualism and high/stable family values had lower SU risk compared to youth who primarily spoke English and endorsed decreasing family values, respectively. Ethnic pride trajectories were not associated with SU. Findings highlight the importance of considering cultural change related to Latino youth SU.     

What is the Effect of Case-Based Learning on the Academic Achievement of Students on the Topic of “Biochemical Oxygen Demand?”

Research in Science Education - The purpose of this study was to investigate the effect of the case-based learning (CBL) method used in “biochemical oxygen demand (BOD),” which is a...