An optimum non-circular chainwheel design for a bicycle drive system

A new and systematic approach for the analysis and simulation of a non-circular chainwheel in a bicycle drive system is presented. The proposed leg-bicycle model is based on a five-bar linkage and explicit expressions for the kinematics and kinetics are derived. The generated shape of the chainwheel is smoothed to an ellipse, for practical reasons. The performance of this elliptical chainwheel is assessed by comparing the joint moments, leg angular accelerations, crank angular velocities, crank angular accelerations and output forces with those of a conventional circular chainwheel. The results suggest combining the elliptical and circular chainwheels into a single unit, in order to accommodate a wide range of pedalling speeds. At low speeds, the elliptical chainwheel is engaged, but as the speed increases, a switch over to the circular chainwheel is recommended.     

Do You Want to Know What I Learned? Using Informational Trade Books as Models to Teach Text Structure

Informational text is an important resource for classroom teachers that places unique comprehension demands on young students. Research on teaching expository text structure to young children shows that explicit instruction improves student comprehension. This practical article addresses how to use “well-structured” expository trade book titles to teach text structure. A lesson plan template and an extended example of an explicit lesson on order/sequence are provided.     

Addressing Health Disparities in the Undergraduate Curriculum: An Approach to Develop a Knowledgeable Biomedical Workforce

Disparities in health and healthcare are a major concern in the United States and worldwide. Approaches to alleviate these disparities must be multifaceted and should include initiatives that touch upon the diverse areas that influence the healthcare system. Developing a strong biomedical workforce with an awareness of the issues concerning health disparities is crucial for addressing this issue. Establishing undergraduate health disparities courses that are accessible to undergraduate students in the life sciences is necessary to increase students’ understanding and awareness of these issues and motivate them to address these disparities during their careers. The majority of universities do not include courses related to health disparities in their curricula, and only a few universities manage them from their life sciences departments. The figures are especially low for minority-serving institutions, which serve students from communities disproportionally affected by health disparities. Universities should consider several possible approaches to infuse their undergraduate curricula with health disparities courses or activities. Eliminating health disparities will require efforts from diverse stakeholders. Undergraduate institutions can play an important role in developing an aware biomedical workforce and helping to close the gap in health outcomes.     

Children’s shyness: a suitable case for treatment?

Shy and withdrawn behaviours are cause for concern and have attracted contrasting perspectives. On the one hand, they are regarded as predictive of social anxiety disorder and may benefit from intervention; on the other hand, there are claims that normal behaviours are being pathologised. Evidence is reviewed which suggests that while they represent a risk factor for social anxiety disorder, these patterns of behaviours are only moderately predictive, the large majority of shy children do not go on to meet diagnostic criteria for social anxiety disorder, nor have adults who meet these criteria necessarily been shy as children. A fruitful approach may be to develop effective social and emotional learning programmes to increase children’s understanding of shyness and to aid identification of children at risk.