Challenging Pre-Service Students\u27 Teaching Perspectives in an Inquiry-Focused Program

Inquiry teaching based on constructivist learning theory has been an emphasis in pre-service education for over a decade. In general, a developmental teaching perspective supports inquiry-based instruction where teachers view learners as constructors of knowledge and teaching as providing questions, problems, and challenges that form a bridge from the learners\u27 prior knowledge to a new, more sophisticated form of reasoning. Since teaching perspectives influence student learning, teacher effectiveness, and teacher attrition, challenging pre-service teachers to overcome experience-based convictions of a transmission perspective is necessary in teacher education. In this study, we examined the teaching perspectives of secondary, pre-service methods students at the midpoint of an inquiry-focused program. Our findings suggest that, despite being introduced to a variety of teaching perspectives, overcoming preconceptions of good teaching and considering a perspective counter to one\u27s disciplinary major presents a dilemma for pre-service teachers

Tradeoff Between Stability and Multispecificity in the Design of Promiscuous Proteins

Natural proteins often partake in several highly specific protein-protein interactions. They are thus subject to multiple opposing forces during evolutionary selection. To be functional, such multispecific proteins need to be stable in complex with each interaction partner, and, at the same time, to maintain affinity toward all partners. How is this multispecificity acquired through natural evolution? To answer this compelling question, we study a prototypical multispecific protein, calmodulin (CaM), which has evolved to interact with hundreds of target proteins. Starting from high-resolution structures of sixteen CaM-target complexes, we employ state-of-the-art computational methods to predict a hundred CaM sequences best suited for interaction with each individual CaM target. Then, we design CaM sequences most compatible with each possible combination of two, three, and all sixteen targets simultaneously, producing almost 70,000 low energy CaM sequences. By comparing these sequences and their energies, we gain insight into how nature has managed to find the compromise between the need for favorable interaction energies and the need for multispecificity. We observe that designing for more partners simultaneously yields CaM sequences that better match natural sequence profiles, thus emphasizing the importance of such strategies in nature. Furthermore, we show that the CaM binding interface can be nicely partitioned into positions that are critical for the affinity of all CaM-target complexes and those that are molded to provide interaction specificity. We reveal several basic categories of sequence-level tradeoffs that enable the compromise necessary for the promiscuity of this protein. We also thoroughly quantify the tradeoff between interaction energetics and multispecificity and find that facilitating seemingly competing interactions requires only a small deviation from optimal energies. We conclude that multispecific proteins have been subjected to a rigorous optimization process that has fine-tuned their sequences for interactions with a precise set of targets, thus conferring their multiple cellular functions

Challenging pre-service students' teaching perspectives in an inquiry-focused program

Inquiry teaching based on constructivist learning theory has been an emphasis in pre-service education for over a decade. In general, a developmental teaching perspective supports inquiry-based instruction where teachers view learners as constructors of knowledge and teaching as providing questions, problems, and challenges that form a bridge from the learners’ prior knowledge to a new, more sophisticated form of reasoning. Since teaching perspectives influence student learning, teacher effectiveness, and teacher attrition, challenging pre-service teachers to overcome experience-based convictions of a transmission perspective is necessary in teacher education. In this study, we examined the teaching perspectives of secondary, pre-service methods students at the midpoint of an inquiry focused program. Our findings suggest that, despite being introduced to a variety of teaching perspectives, overcoming preconceptions of “good teaching” and considering a perspective counter to one’s disciplinary major presents a dilemma for pre-service teachers.final article publishedJournal Articl

Formal lessons improve informal educational experiences: The influence of prior knowledge on student engagement

Educational experiences can be influenced by novel experiences, yet educators often overlook the influence novelty exerts on students. This quasi-experimental study manipulated prior knowledge before a zoo field trip for 210 urban 7th-grade students from 2 schools, 1 comprised mostly of low-socioeconomic status (SES) families and 1 comprised mostly of middle-SES families. Students participated in 1 of 2 preparatory lessons, only 1 of which previewed field trip-related content, thereby increasing prior knowledge for half the students from each school. Prior knowledge significantly increased learner engagement, measured through attentiveness, from both schools, but in different types of behaviors. Students from the low-SES school demonstrated more attentiveness if their preparatory lesson previewed field trip material than if it was unrelated to the field trip. Students from the middle SES school displayed the same level of attentiveness in both conditions (and overall higher than the low-SES students). This study highlights complexities associated with prior knowledge and reveals strategies to help improve engagement levels for students visiting informal learning environments.Journal Articl

Portraits of science self-efficacy: Four undergraduate women in a summer research experience

To strengthen the US scientific workforce, we aim to recruit and retain talented students in science, technology, engineering, and math (STEM) fields, to enhance success among students from groups underrepresented in STEM fields, and to diversify the scientific workforce to mirror the US population. Given that opportunities for authentic research may support STEM advancement, we seek to maximize the number of students involved in research. Our Behavioral Research Advancements in Neuroscience (BRAIN) research program tests the hypothesis that a term-based collaborative-learning model not only provides research opportunities for more students, nut also produces outcomes at least as positive as a traditional one-on-one apprenticeship model. We examined scientific research self-efficacy as a critical construct for measuring student outcomes and predicting student progress toward STEM careers. Here we provide descriptive portraits of four women who participated in BRAIN, integrating quantitative survey data with analysis of pre- and post-semistructured interviews. Although selected for different self-efficacy trajectories in the quantitative surveys, all four women described increased self-efficacy in interviews and emphasized mastery experiences as a source of self-efficacy. Two women illustrate one general outcome from the program: women overcame initially lower scientific research self-efficacy, matching self-efficacy among men by mid-program. The overarching study suggests that both team-based research and apprenticeships can raise scientific research self-efficacy, which predicts STEM career success. Therefore, this collaborative model provides a structure for authentic research at institutions that may lack available mentors, and yet aim to improve opportunities for diverse undergraduate groups to pursue STEM careers.Journal Articl

α-amanitin resistance in Drosophila melanogaster: A genome-wide association approach

© This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication. We investigated the mechanisms of mushroom toxin resistance in the Drosophila Genetic Reference Panel (DGRP) fly lines, using genome-wide association studies (GWAS). While Drosophila melanogaster avoids mushrooms in nature, some lines are surprisingly resistant to α-amanitin-a toxin found solely in mushrooms. This resistance may represent a preadaptation, which might enable this species to invade the mushroom niche in the future. Although our previous microarray study had strongly suggested that pesticide-metabolizing detoxification genes confer α-amanitin resistance in a Taiwanese D. melanogaster line Ama-KTT, none of the traditional detoxification genes were among the top candidate genes resulting from the GWAS in the current study. Instead, we identified Megalin, Tequila, and widerborst as candidate genes underlying the α-amanitin resistance phenotype in the North American DGRP lines, all three of which are connected to the Target of Rapamycin (TOR) pathway. Both widerborst and Tequila are upstream regulators of TOR, and TOR is a key regulator of autophagy and Megalin-mediated endocytosis. We suggest that endocytosis and autophagy of α-amanitin, followed by lysosomal degradation of the toxin, is one of the mechanisms that confer α-amanitin resistance in the DGRP lines

Combining computational and experimental screening for rapid optimization of protein properties

We present a combined computational and experimental method for the rapid optimization of proteins. Using β-lactamase as a test case, we redesigned the active site region using our Protein Design Automation technology as a computational screen to search the entire sequence space. By eliminating sequences incompatible with the protein fold, Protein Design Automation rapidly reduced the number of sequences to a size amenable to experimental screening, resulting in a library of ≈200,000 mutants. These were then constructed and experimentally screened to select for variants with improved resistance to the antibiotic cefotaxime. In a single round, we obtained variants exhibiting a 1,280-fold increase in resistance. To our knowledge, all of the mutations were novel, i.e., they have not been identified as beneficial by random mutagenesis or DNA shuffling or seen in any of the naturally occurring TEM β-lactamases, the most prevalent type of Gram-negative β-lactamases. This combined approach allows for the rapid improvement of any property that can be screened experimentally and provides a powerful broadly applicable tool for protein engineering

Candidate genes resulting from the 180-line GWAS on 2.0 μg/g and the 37-line GWAS.

<p>Candidate genes resulting from the 180-line GWAS on 2.0 μg/g and the 37-line GWAS.</p