Researchers who work on course-based undergraduate research experiences (CUREs) and issues related to science, technology, engineering, and math (STEM) retention have begun exploring changes in student thinking about what it means to be a scientist. To support this effort, we developed rubrics to score answers to three open-response prompts: What does it mean to think like a scientist? What does it mean to do science? and Did you do real research in your labs? The rubric development process was iterative and was based on input from the literature, experienced researchers, and early-career undergraduates. A analysis showed that the rubric elements map to 27 of 31 statements in the Culture of Scientific Research (CSR) framework, suggesting that scored responses to the three prompts can assess how well students understand what being a science professional entails.
View Article and Find Full Text PDFWe developed labs on the evolution of antibiotic resistance to assess the costs and benefits of replacing traditional laboratory exercises in an introductory biology course for majors with a course-based undergraduate research experience (CURE). To assess whether participating in the CURE imposed a cost in terms of exam performance, we implemented a quasi-experiment in which four lab sections in the same term of the same course did the CURE labs, while all other students did traditional labs. To assess whether participating in the CURE impacted other aspects of student learning, we implemented a second quasi-experiment in which all students either did traditional labs over a two-quarter sequence or did CURE labs over a two-quarter sequence.
View Article and Find Full Text PDFResearchers have called for undergraduate courses to update teaching frameworks based on the Modern Synthesis with insights from molecular biology, by stressing the molecular underpinnings of variation and adaptation. To support this goal, we developed a modified version of the widely used Assessing Conceptual Reasoning of Natural Selection (ACORNS) instrument. The expanded tool, called the E-ACORNS, is explicitly designed to test student understanding of the connections among genotypes, phenotypes, and fitness.
View Article and Find Full Text PDFThe susceptibility of Cronobacter sakazakii ATCC 29544 (CS) and Yersinia enterocolitica ATCC 9610 (YE) to sodium hypochlorite (10% of active chlorine; SHY), peracetic acid (39% solution of peracetic acid in acetic acid; PAA) and benzalkonium chloride (BZK) was tested. Minimum inhibitory concentration (MIC) values (planktonic cells; microdilution broth method) of 3,800 ppm (SHY), 1,200 ppm (PAA) and 15 ppm (BZK) for CS, and 2,500 ppm (SHY), 1,275 ppm (PAA) and 20 ppm (BZK) for YE, were found. In some instances, an increase in growth rate was observed in presence of sub-MICs (0.
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