Polymerase chain reaction: It’s diagnostic application

The development of the Polymerase Chain Reaction (PCR) has been a major technical milestone in molecular genetics with the greatest impact on research, in rapid medical diagnosis and in studying the pathogenesis of disease. This study highlights the practical applications of polymerase chain reaction in diagnosis and includes a recent application of PCR in differentiating polio from other nonpolio enteroviruses.     

Navigating complexity,culture, collaboration,and emotion: student perspectives on global justice and global justice education

Recent years have seen increasing scholarly attention to the ways in which colleges and universities might contribute to educating ‘global citizens’ who work toward addressing injustice and inequity. The present study examines the experiences and perspectives of students participating in an upper level ‘global justice inquiry’ course designed to help meet this goal. Drawing from interviews with students and reflections submitted as part of their course assessment, we explore participants’ developing understanding of global justice and their experiences of learning about this topic. This investigation reveals key issues that students highlight and with which they sometimes struggle, including the complexity of global challenges, the importance of collaboration in attempting to address such challenges, the significance of navigating cultural considerations, and the potential influence of emotion on understanding and action. Implications of these findings, including the potential value of considering these issues as threshold concepts in global justice education, are discussed.     

The Genetic Drift Inventory: A Tool for Measuring What Advanced Undergraduates Have Mastered about Genetic Drift

Understanding genetic drift is crucial for a comprehensive understanding of biology, yet it is difficult to learn because it combines the conceptual challenges of both evolution and randomness. To help assess strategies for teaching genetic drift, we have developed and evaluated the Genetic Drift Inventory (GeDI), a concept inventory that measures upper-division students’ understanding of this concept. We used an iterative approach that included extensive interviews and field tests involving 1723 students across five different undergraduate campuses. The GeDI consists of 22 agree–disagree statements that assess four key concepts and six misconceptions. Student scores ranged from 4/22 to 22/22. Statements ranged in mean difficulty from 0.29 to 0.80 and in discrimination from 0.09 to 0.46. The internal consistency, as measured with Cronbach''s alpha, ranged from 0.58 to 0.88 across five iterations. Test–retest analysis resulted in a coefficient of stability of 0.82. The true–false format means that the GeDI can test how well students grasp key concepts central to understanding genetic drift, while simultaneously testing for the presence of misconceptions that indicate an incomplete understanding of genetic drift. The insights gained from this testing will, over time, allow us to improve instruction about this key component of evolution.     

Student absences during learning cycle phases: a technological alternative for make-up work in laboratory based high school chemistry

Absences from school present a major obstacle to students' gaining understandings of concepts developed in class. Moreover, teachers' finding effective ways for students to make up missed work is a continual problem, especially for laboratory-based science classes. In an exploratory study, we investigated an alternative procedure for making up missed class work: viewing a quasi-interactive videotaped presentation of missed portions of a learning cycle in chemistry. Two treatment groups were involved. One group of students completed data sheets while watching a videotape, then wrote answers to questions posed by the videotaped instructor. This procedure simulated make-up work. A second group of students participated in a conventional learning cycle: exploration, conceptual invention and concept application. Results demonstrate that teachers can videotape investigations to conveniently and effectively use as make-up assignments for a chemistry learning cycle.