Specific muscle synergies in national elite female ice hockey players in response to unexpected external perturbation

This study aimed to investigate specific muscle synergies in elite ice hockey players indicating highly developed postural control strategies used to restore balance against unexpected external perturbations. Seven elite athletes (EA) on the women’s national ice hockey team and 7 non-athletes (NA) participated in this study. Based on trajectories of centre of mass (COM), analysis periods were divided into an initial phase (a balance disturbance after perturbation onset) and a reversal phase (a balance recovery response), respectively. Muscle synergies were extracted at each phase by using non-negative matrix factorization. k-means cluster analysis was performed to arrange similar muscle synergies in all participants. EA showed significantly shorter recovery period of COM and smaller body sway than NA. In the initial phase, we identified 2 EA-specific synergies related to ankle plantar flexors or neck extensors. In the case of an NA-specific synergy, co-activation of the ankle plantar flexors and dorsiflexors was found. In the reversal phase, no specific muscle synergies were identified. As the results, EA-specific muscle synergies showed low co-activation strategy of agonists and antagonists in ankle and neck extensors. Our results could provide critical information for rehabilitation strategies in athletes requiring high postural stability.     

Building a Culture of Engagement through Participatory Feedback Processes

In response to school environments in which teachers and students feel disconnected from the learning process, we developed a three-part curriculum feedback system with the goal of creating a school-wide culture of engagement through participatory feedback processes. Here we describe the barriers to participation and ownership that are addressed by our curriculum feedback process, provide a rationale for each component of the multi-prong feedback process, and illustrate how each part of the feedback system was implemented in our pilot schools. We argue that addressing feedback regularly, optimizing the process to be user-friendly, and demonstrating appreciation for positive and constructive feedback can help any curriculum supervisor foster a school-wide culture of engagement among teachers and students.     

The Effect of Positive Faculty Support on Mathematical Self-Concept for Male and Female Students in STEM Majors

Using hierarchical linear modeling, this study examined how positive faculty support is associated with mathematical self-concept development among students in STEM fields and how the association differs for male and female students. The study utilized data from the 2003 Freshman Survey and the 2007 College Senior Survey (CSS) and a sample of 2184 students across 27 baccalaureate institutions nationwide. This study found that positive faculty support was significantly and positively related to STEM students’ mathematical self-concept development in general; however, this positive connection held for male STEM students only. Findings also suggested that female STEM students’ mathematical self-concept remained significantly below males’ throughout college and positive faculty support did not narrow the persistent gender gap in this area. The study discusses the theoretical and practical implications of the findings.     

Reflexivity,positionality and power in cross-cultural participatory action research with research assistants in rural Cambodia

This paper draws on the experiences of a doctoral student undertaking a cross-cultural, cross-language participatory action research (PAR) project in rural Cambodia. Cambodia is a largely Buddhist country with a complex history of religion, invasion, colonisation, war and oppression. Despite a democratic constitution, political control and fear of challenging authority are ever present; and all had an impact on the participation and development of this project. I recruited eight volunteer community health workers (CHWs) and two research assistants (RAs) with an aim to explore methods and challenges faced when trying to improve health with and for community members. Over eight participatory workshops and a two-day training session CHWs identified, implemented and reflected on solutions to community health problems. Simultaneously, the RAs and I reflected on the processes and challenges we faced. Creating opportunity for reflexivity allowed for discussion to emerge around culture, position and power and how these were impacting on the research process and outcomes. Established social hierarchical power structures in Cambodia presented challenges to undertaking a PAR project with emancipatory and social change aims. Such structures also impacted on the ability and readiness of participants to be critical and analytical. The importance of the RAs as cultural navigators and the necessity of embracing their situated knowledge as both an insider and outsider is a key finding.     

Is there a startup wage premium? Evidence from MIT graduates

While startups are the center of extensive policy discussion given their outsized role in job creation, it is not clear whether they create high quality jobs relative to incumbent firms. This paper investigates the wage differential between venture capital-backed startups and established firms, given that the two firm types compete for talent. Using data on MIT graduates, I find that non-founder employees at VC-backed startups earn roughly 10% higher wages than their counterparts at established firms. To account for unobserved heterogeneity across workers, I exploit the fact that many MIT graduates receive multiple job offers. I find that wage differentials are statistically insignificant from zero when individual fixed effects are included. This implies that much of the startup wage premium in the cross-section can be attributed to selection, and that VC-backed startups pay competitive wages for talent. To unpack the selection mechanism, I show that individual preferences for risk as well as challenging work strongly predict entry into VC-backed startups.     

大学文凭价值几何？

A new report estimates--to the dollar---how much a degree boosts your income and other benefits.     

Li-ion battery material under high pressure: amorphization and enhanced conductivity of Li4Ti5O12

Lithium titanium oxide (Li₄Ti₅O₁₂, LTO), a ‘zero-strain’ anode material for lithium-ion batteries, exhibits excellent cycling performance. However, its poor conductivity highly limits its applications. Here, the structural stability and conductivity of LTO were studied using in situ high-pressure measurements and first-principles calculations. LTO underwent a pressure-induced amorphization (PIA) at 26.9 GPa. The impedance spectroscopy revealed that the conductivity of LTO improved significantly after amorphization and that the conductivity of decompressed amorphous LTO increased by an order of magnitude compared with its starting phase. Furthermore, our calculations demonstrated that the different compressibility of the LiO₆ and TiO₆ octahedra in the structure was crucial for the PIA. The amorphous phase promotes Li⁺ diffusion and enhances its ionic conductivity by providing defects for ion migration. Our results not only provide an insight into the pressure depended structural properties of a spinel-like material, but also facilitate exploration of the interplay between PIA and conductivity.     

Integrating special-needs children into a preschool setting

For further information, write to Kim Stoddard, College of Education, University of South Florida—St. Petersburg, 140 7th Ave. South, St. Petersburg, FL 33701.