523 research outputs found
Retinal pigmented epithelium does not transdifferentiate in adult goldfish
The neural retina of adult goldfish can regenerate from an intrinsic source of proliferative neuronal progenitor cells, but it is not known whether the retina can regenerate by transdifferentiation of the retinal pigmented epithelium (RPE), a phenomenon demonstrated in adult newts. In this study, we asked whether following surgical removal of the neural retina in adult goldfish the RPE was capable of autonomously transdifferentiating and generating new neural retina. The retina was prelabeled by injecting the fluorescent dye Fluoro-Gold (FG) into the eye prior to surgical removal; this procedure ensured that residual retina was labeled with FG and could therefore be distinguished from unlabeled, regenerated retina. To examine the time course of retinal regeneration, and to identify regenerated retinal neurons, the thymidine analogue bromodeoxyuridine was injected intraocularly, and retinas were examined up to 2 months later. We found that the RPE did not transdifferentiate; instead, retinas regenerated only when pieces of residual neural retina were left intact. Under these circumstances, newly regenerated cells derived from proliferating cells intrinsic to the residual neural retina. When retinas were completely removed, as was evident from a lack of FG labeling, there was no retinal regeneration. © 1995 John Wiley & Sons, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50086/1/480270402_ftp.pd
Writing Across Campus: Using Authentic Writing Experiences to Help Pre-Service Teachers Learn to Teach Writing
This study demonstrates the impact asynchronous discussion boards had on cross-college preservice teachers writing and writing instruction understanding. Participants from two universities in writing methods courses participated in discussion boards to learn about writing instruction. Students in the groups not only asked higher-level depth of knowledge questions to each other, but they also began to focus their responses and comments about their future teaching and instructional practices. Students built a stronger community of writers than students in previous courses that read, responded, and replied to peers
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Problem Solving in Genetics: Content Hints Can Help
Problem solving is an integral part of doing science, yet it is challenging for students in many disciplines to learn. We explored student success in solving genetics problems in several genetics content areas using sets of three consecutive questions for each content area. To promote improvement, we provided students the choice to take a content-focused prompt, termed a “content hint,” during either the second or third question within each content area. Overall, for students who answered the first question in a content area incorrectly, the content hints helped them solve additional content-matched problems. We also examined students’ descriptions of their problem solving and found that students who improved following a hint typically used the hint content to accurately solve a problem. Students who did not improve upon receipt of the content hint demonstrated a variety of content-specific errors and omissions. Overall, ultimate success in the practice assignment (on the final question of each topic) predicted success on content-matched final exam questions, regardless of initial practice performance or initial genetics knowledge. Our findings suggest that some struggling students may have deficits in specific genetics content knowledge, which when addressed, allow the students to successfully solve challenging genetics problems.</p
Understanding Lung Cancer Resources and Barriers among Worksites with Mostly Male Employees in Eight Rural Kentucky Counties: A Focus Group Discussion
Kentucky has the highest cancer incidence and mortality rates in the United States, and lung cancer is Kentucky\u27s leading cause of cancer deaths. Males in Kentucky have higher lung incidence and mortality rates than females. Through support from the SelfMade Health Network, Kentucky developed a Regional Resource Lead Organization that collaboratively developed a multi-component worksite intervention on lung cancer among male populations. The intervention targets eight Kentucky counties. The first component and focus of this manuscript included focus group meetings with organizational representatives in each county that provide health, educational, and social services to men and worksites. The focus groups discussed four distinct areas: (a) lung cancer-related resources and services in each county; (b) perceived ways men in worksites learn about and access health-related services; (c) identification of potential challenges and barriers to reaching men in worksites; and (d) creation of linkages and potential partnerships between community organizations and worksites. Forty-five organizational representatives participated in the eight focus groups. Most resources and services discussed were related to tobacco treatment. Employers were the most commonly perceived way men learn about and access health-related services, while attitudes and behaviors were the most commonly perceived barriers preventing men from accessing services. The most common potential linkages and partnerships across all areas were community organizations and groups, employers, health-care providers, and mass media. Partnering with employers may provide an opportunity to reach males with lung cancer prevention and control resources and services
Student, instructor, and observer agreement regarding frequencies of scientific teaching practices using the Measurement Instrument for Scientific Teaching-Observable (MISTO)
Background: The Scientific Teaching (ST) pedagogical framework encompasses many of the best practices recommended in the literature and highlighted in national reports. Understanding the growth and impact of ST requires instruments to accurately measure the extent to which practitioners implement ST in their courses. Researchers have typically relied on students, instructors, or observers to document course teaching practices, but it remains unclear whether and how these perspectives differ from each other. To address this issue, we modified our previously published instrument to generate the Measurement Instrument for Scientific Teaching-Observable (MISTO), which can be completed by students, instructors, and observers, and we investigated the degree of similarity between these three perspectives across 70 undergraduate science courses at seven different institutions in the USA.
Results: We found that the full MISTO and Active Learning subcategory scores showed the highest correlations among the three perspectives, but the degree of correlation between perspectives varied for the other subcategories. Match scores between students and instructors were significantly higher than observer matches for the full MISTO and for the Active Learning, Inclusivity, and Responsiveness subcategories.
Conclusions: We find that the level and type of agreement between perspectives varies across MISTO subcategories and that this variation likely stems from intrinsic differences in the course access and scoring decisions of the three perspectives. Building on this data, we recommend MISTO users consider their research goals, available resources, and potential artifacts that may arise when deciding which perspective best fits their needs in measuring classroom teaching practices
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Successful Problem Solving in Genetics Varies Based on Question Content
Problem solving is a critical skill in many disciplines but is often a challenge for students to learn. To examine the processes both students and experts undertake to solve constructed-response problems in genetics, we collected the written step-by-step procedures individuals used to solve problems in four different content areas. We developed a set of codes to describe each cognitive and metacognitive process and then used these codes to describe more than 1800 student and 149 expert answers. We found that students used some processes differently depending on the content of the question, but reasoning was consistently predictive of successful problem solving across all content areas. We also confirmed previous findings that the metacognitive processes of planning and checking were more common in expert answers than student answers. We provide suggestions for instructors on how to highlight key procedures based on each specific genetics content area that can help students learn the skill of problem solving.
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EcoEvo-MAPS: An Ecology and Evolution Assessment for Introductory through Advanced Undergraduates
A new assessment tool, Ecology and Evolution–Measuring Achievement and Progression in Science or EcoEvo-MAPS, measures student thinking in ecology and evolution during an undergraduate course of study. EcoEvo-MAPS targets foundational concepts in ecology and evolution and uses a novel approach that asks students to evaluate a series of predictions, conclusions, or interpretations as likely or unlikely to be true given a specific scenario. We collected evidence of validity and reliability for EcoEvo-MAPS through an iterative process of faculty review, student interviews, and analyses of assessment data from more than 3000 students at 34 associate’s-, bachelor’s-, master’s-, and doctoral-granting institutions. The 63 likely/unlikely statements range in difficulty and target student understanding of key concepts aligned with the Vision and Change report. This assessment provides departments with a tool to measure student thinking at different time points in the curriculum and provides data that can be used to inform curricular and instructional modifications
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Demystifying the Meaning of Active Learning in Postsecondary Biology Education
Active learning is frequently used to describe teaching practices, but the term is not well-defined in the context of undergraduate biology education. To clarify this term, we explored how active learning is defined in the biology education literature ( = 148 articles) and community by surveying a national sample of biology education researchers and instructors ( = 105 individuals). Our objectives were to increase transparency and reproducibility of teaching practices and research findings in biology education. Findings showed the majority of the literature concerning active learning never defined the term, but the authors often provided examples of specific active-learning strategies. We categorized the available active-learning definitions and strategies obtained from the articles and survey responses to highlight central themes. Based on data from the BER literature and community, we provide a working definition of active learning and an Active-Learning Strategy Guide that defines 300+ active-learning strategies. These tools can help the community define, elaborate, and provide specificity when using the term active learning to characterize teaching practices.</p
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