Effects of Grip and Forearm Position on Flexed-Arm Hang Performance

Abstract

The purposes of this study were to associate age-related performance deficits in children with the use of recall strategies and to determine whether children who performed poorly in cycling would benefit from learning a recall strategy. In Experiment 1, 18 younger children (ages 5-7 years) and 18 older children (ages 8-10 years) were asked to recall selected pedaling cadences. The majority of the older children used strategies and performed with less error than the younger children. In Experiment 2, children with a high number of errors in Experiment 1 were assigned to an experimental or a control group. The children in the experimental group were taught to use a specific recall strategy. The results showed that children who received the instruction in strategy use improved their performance.     

Microliter-bioreactor array with buoyancy-driven stirring for human hematopoietic stem cell culture

This work presents the development of an array of bioreactors where finely controlled stirring is provided at the microliter scale (100–300 μl). The microliter-bioreactor array is useful for performing protocol optimization in up to 96 parallel experiments of hematopoietic stem cell (HSC) cultures. Exploring a wide range of experimental conditions at the microliter scale minimizes cost and labor. Once the cell culture protocol is optimized, it can be applied to large-scale bioreactors for stem cell production at the clinical level. The controlled stirring inside the wells of a standard 96-well plate is provided by buoyancy-driven thermoconvection. The temperature and velocity fields within the culture volume are determined with numerical simulations. The numerical results are verified with experimental velocity measurements using microparticle image velocimetry (μPIV) and are used to define feasible experimental conditions for stem cell cultures. To test the bioreactor array’s functionality, human umbilical cord blood-derived CD34⁺ cells were cultured for 7 days at five different stirring conditions (0.24–0.58 μm∕s) in six repeated experiments. Cells were characterized in terms of proliferation, and flow cytometry measurements of viability and CD34 expression. The microliter-bioreactor array demonstrates its ability to support HSC cultures under stirred conditions without adversely affecting the cell behavior. Because of the highly controlled operative conditions, it can be used to explore culture conditions where the mass transport of endogenous and exogenous growth factors is selectively enhanced, and cell suspension provided. While the bioreactor array was developed for culturing HSCs, its application can be extended to other cell types.     

Cope,Conform, or Resist? Functions of a Black American Identity at a Predominantly White University

This study organized five black American undergraduate students into a participatory action research (PAR) team to examine Cross and Strauss’ (1998) and Cross, Smith, and Payne's (2002) functions of blackness theory (i.e., bonding, code switching, and individualism) within a sample of black American students, frontline staff (i.e., janitors), and faculty at a predominantly white institution (PWI) or university. The racial-ethnic lived experiences of black Americans at a PWI can reveal outcomes in terms of employee performance and student academic and social experience. Data were collected from four student focus groups (i.e., general student body, students in Greek organizations, student athletes, and student leaders), one frontline staff focus group, five individual faculty interviews, and one individual interview with a female student athlete. Each participant completed a demographic survey. Also, extensive field observations were taken of participants at this particular PWI. Findings revealed how black Americans use bonding, code switching and individualism as functions of a racial identity when navigating a PWI as a mainstream environment. Data suggest very little bonding took place across the three subsamples (i.e., students, frontline staff, and faculty) and bonding practiced by black Americans at this PWI was found to exist most often within subpopulations, specifically within students and frontline staff. Participants, overall, were comfortable with code switching between a professional identity and a more racial, black American and/or social identity. Also, a number of participants understood their individuality to be more salient than a racial or black American identity. Implications for PAR projects with black American college students are also discussed within this article.     

Post-activation potentiation (PAP) in endurance sports: A review

While there is strong support of the usefulness of post-activation potentiation (PAP) phenomenon in power demanding sports, the role that PAP could play in endurance sports has received less attention. The aim of this review is to present evidence for a better understanding of PAP in endurance athletes; and to discuss the physiological basis and methodological aspects necessary for better practices and designing further studies. A search for relevant articles on PAP and endurance trained athletes was carried out using Medline and ISI Web of Knowledge databases. Twenty-two studies were included in the review. The current evidence suggests the possible influence of PAP for performance enhancement after appropriate conditioning activities during warm up. Evaluation of PAP responses during testing, training and competition may be also important for athletes monitoring. There are many unresolved questions about the optimum load parameters for benefiting from PAP in both training and competition; and the role that PAP may exert for optimal performance while interacting with central and peripheral factors associated with muscle fatigue. Further studies should elucidate the association between PAP responses and long-term adaptations in endurance athletes.     

Creating effective teaching and learning environments: Building a positive behavioural support (PBS) model for UK special schools

The importance of reducing restraint and restrictive interventions in special schools has been recognised across the four nations of the UK. Government guidance for England and Wales, and recommendations produced by Restraint Reduction Scotland, both reference Positive behavioural support (PBS) as an evidence-based approach that can be used to proactively support pupils with, or at risk of, behaviours that challenge. The Department of Education of Northern Ireland recommends the development of behaviour support plans to support children with special education needs and disabilities. Special schools, however, also have a responsibility to set high expectations for every pupil, to provide access to the respective national curricula and to meet individual needs. School-wide positive behavioural support (SW-PBS), originated in the USA in the 1990s in response to a body of evidence that showed improved social and academic outcomes when behavioural interventions were implemented across whole school settings. It is increasingly being adopted in the UK. Drawing upon examples from schools in England and Wales with which the authors are familiar, this paper outlines the rationale for a special schools' model of SW-PBS and illustrates the ways in which this can be adjusted to meet the specific needs of each setting.

Key Points

• Reducing restraint and restrictive interventions in schools is a high priority across all four nations of the UK.
• Special schools also have a responsibility to provide children with special education needs and disabilities positive learning environments that maximise learning opportunities and meet individual needs.
• School-wide positive behaviour support (SW-PBS) provides a useful framework to help special schools meet these expectations.