Polyglutamine monomer structure and its implications for molecular self-assembly

Polyglutamine is a naturally occurring peptide found within several proteins in neuronal cells of the brain, and its aggregation has been implicated in several neurodegenerative diseases, including Huntington's disease. The resulting aggregates have been demonstrated to possess ~-sheet structure, and aggregation has been shown to start with a single misfolded peptide. The current project sought to computationally examine the structural tendencies of three mutant poly glutamine peptides that were studied experimentally, and found to aggregate with varying efficiencies. Low-energy structures were generated for each peptide by simulated annealing, and were analyzed quantitatively by various geometry- and energy-based methods. According to the results, the experimentally-observed inhibition of aggregation appears to be due to localized conformational restraint placed on the peptide backbone by inserted prolines, which in tum confines the peptide to native coil structure, discouraging transition towards the ~sheet structure required for aggregation. Such knowledge could prove quite useful to the design of future treatments for Huntington's and other related diseases.

The role of physical activity and perceived adequacy on cardiorespiratory fitness in children with developmental coordination disorder

Evidence suggests that children with developmental coordination disorder (DCD) have lower levels of cardiorespiratory fitness (CRF) compared to children without the condition. However, these studies were restricted to field-based methods in order to predict V02 peak in the determination of CRF. Such field tests have been criticised for their ability to provide a valid prediction of V02 peak and vulnerability to psychological aspects in children with DCD, such as low perceived adequacy toward physical activity. Moreover, the contribution of physical activity to the variance in V02 peak between the two groups is unknown. The purpose of our study was to determine the mediating role of physical activity and perceived adequacy towards physical activity on V02 peak in children with significant motor impairments. This prospective case-control design involved 122 (age 12-13 years) children with significant motor impairments (n=61) and healthy matched controls (n=61) based on age, gender and school location. Participants had been previously assessed for motor proficiency and classified as a probable DCD (p-DCD) or healthy control using the movement ABC test. V02 peak was measured by a progressive exercise test on a cycle ergometer. Perceived adequacy was measured using a 7 -item subscale from Children's Selfperception of Adequacy and Predilection for Physical Activity scale. Physical activity was monitored for seven days with the Actical® accelerometer. Children with p-DCD had significantly lower V02 peak (48.76±7.2 ml/ffm/min; p:50.05) compared to controls (53.12±8.2 ml/ffm/min), even after correcting for fat free mass. Regression analysis demonstrated that perceived adequacy and physical activity were significant mediators in the relationship between p-DCD and V02 peak. In conclusion, using a stringent laboratory assessment, the results of the current study verify the findings of earlier studies, adding low CRF to the list of health consequences associated with DCD. It seems that when testing for CRF in this population, there is a need to consider the psychological barriers associated with their condition. Moreover, strategies to increase physical activity in children with DCD may result in improvement in their CRF.

How are Girls' Attitudes Toward Cyberbullying Affected by Drama for Social Intervention?

This is a study exploring teenaged girls’ understanding and experiences of cyberbullying as a contemporary social phenomenon. Participants included 4 Grade 11 and 12 girls from a medium-sized independent school in southwestern Ontario, Canada. The girls participated in 9 extracurricular study sessions from January to April 2013. During the sessions, they engaged with Drama for Social Intervention (Clark, 2009; Conrad, 2004; Lepp, 2011) activities with the intended goal of producing a collective creation. Qualitative data were collected throughout the sessions using fieldnotes, participant journals, interviews, and participant artefacts. The findings are presented as an ethnodrama (Campbell & Conrad, 2006; Denzin, 2003; Saldaña, 1999) with each thematic statement forming a title of a scene in the script (Rogers, Frellick, & Babinski, 2002). The study found that girl identity online consists of many disconnected avatars. It also suggested that distancing (Eriksson, 2011) techniques, used to engender safety in Drama for Social Intervention, might have contributed to participant disengagement with the study’s content. Implications for further research included the utility of arts-based methods to promote participants’ feelings of growth and reflection, and a reevaluation of cyberbullying discourses to better reflect girls’ multiple avatar identities. Implications for teachers and administrators encompassed a need for preventative approaches to cyberbullying education, incorporating affective empathy-building (Ang & Goh, 2010) and addressing girls’ feelings of safety in perceived anonymity online.