Efficacy Sources that Predict Leadership Behaviors in Coaches of Athletes with Disabilities.

Researchers suggest that sport participation among athletes with disabilities promotes healthier lifestyles, increases self-esteem, and enhances peer acceptance. Ideally, coaches should be confident in teaching skills, tactics, and sportsmanship, while exhibiting appropriate leadership behaviors in order to positively impact the psychosocial development of any athlete. Thus, the present research examined sources of coaching efficacy that predict leadership behaviors in coaches who work with athletes who have physical disabilities. Seventy international Paralympic coaches of female and male sport teams completed a modified version of the Coaching Success Questionnaire-2, the Coaching Efficacy Scale and the Leadership Scale for Sports. Regression models indicated that total coaching efficacy was a significant predictor of instructional and positive feedback leadership behaviors, with prior success also being a significant predictor of instructional behavior.

Effects of transforming growth factor-alpha (TGF-alpha) in vitro and in vivo on reovirus replication.

We have utilized growth factors in in vitro and in vivo systems to examine the role of cellular proliferation in reovirus replication. In vitro, proliferating RIE-1 cells can be infected with whole reovirus virions, but are relatively resistant to infection once confluent (Go arrest). It has been shown that TGF-alpha, which signals through the EGF-receptor (EGF-R), is capable of dramatically increasing the number of RIE-1 cells entering the S-phase in the presence of additional serum factors. Stimulation of the EGF-R without serum results in minimal increases in cells entering the S-phase with a restriction in reovirus replication. Therefore, other factors in serum are essential for fully permissive infection. In vivo, we used metallothionein (MT) promoter/enhancer-TGF-alpha transgenic mice to study the effect of cytokine activation on reovirus type 1 infection. Virus replication decreased following oral infection in these transgenic mice at 1 month of age, concordant with increased mucin production. Titers of reovirus obtained from the livers of 1 year old transgenic mice were approximately 10-fold higher than titers obtained in control mice. Taken together, these data indicate that while growth factor activation ultimately leads to an increase in virus infectivity, other factors may be necessary for reovirus replication.