Collaborative Two-Stage Exams Benefit Students in a Biology Laboratory Course.

Collaborative two-stage exams provide an effective mechanism to incorporate group work into summative course assessments. We implemented these exams in an upper-level biology laboratory course over two terms, one with online exams and one with in-person exams. We compared student exam performance and perceptions of two-stage exams and group work across terms and demographic groups. Quantitative analyses revealed that across three exams per term, students in groups outperformed students who took the exams individually, and on average the group exam benefited all students, in particular students from groups recognized as persons historically excluded from science because of their ethnicity or race (PEERs). Student responses to both closed and open-ended questions indicated overall positive perceptions of both two-stage exams and group work. We found no significant differences in student perceptions based on PEER student status, gender, or the number of exams helped by group exams, but we found differences related to term and group exam approaches. These findings build upon the literature supporting student learning and perceptions from two-stage exams and provide novel insights for a role of group work in decreasing inequities in course assessments.

CRISPR in Your Kitchen: an At-Home CRISPR Kit to Edit Genes in Saccharomyces cerevisiae Used during a Remote Lab Course.

The use of CRISPR-based experiments in an undergraduate course is appealing because of the ease of editing, and the relevance of CRISPR to current research. Before the COVID-19 pandemic, we developed an in-person lab for a high-enrollment course that allowed students to design and conduct CRISPR editing experiments in budding yeast, Saccharomyces cerevisiae. Post pandemic, the lab course moved online, and we lost the hands-on component. We subsequently developed an at-home kit that contained all the necessary materials for students to grow and transform S. cerevisiae with the DNA molecules necessary for CRISPR-Cas9 induced editing. Our at-home kits cost approximately $70 each to produce and were shipped to over 600 students during the 2020 to 2021 academic year. By adding the at-home experimental work to our remote, online lab course, students were able to generate loss-of-function mutants in ADE2 (causing a red color phenotype). Students were able to send edited yeast samples back to campus for sequencing, allowing for characterization of the different mutations that can occur due to CRISPR-Cas9 induced editing. Here, we described the protocol to produce and use the kits and summarized the student experience of using the at-home kit in a large enrollment, remote lab course. These kits provided opportunities to engage students in hands-on experimentation during a remote course and could also be used to reach learners in other domains, such as high schools and outreach programs.

A framework for educating and empowering students by teaching about history and consequences of bias in STEM.

Racism and bias are pervasive in society-and science, technology, engineering, and mathematics (STEM) fields are not immune to these issues. It is imperative that we educate ourselves and our students about the history and consequences of this bias in STEM, investigate the research showing bias toward marginalized groups, understand how to interpret misuses of science in perpetuating bias, and identify advances and solutions to overcome racism and bias throughout our professional and personal lives. Here, we present one model for teaching a universal course for participants of all professional stages to address these issues and initiate solutions. As very few institutions require students to enroll in courses on racism and bias in STEM or even offer such courses, our curriculum could be used as a blueprint for implementation across institutions. Ultimately, institutions and academic disciplines can incorporate this important material with more region and/or discipline specific studies of bias.

Am I getting through? Surveying students on what messages they recall from the first day of STEM classes.

BACKGROUND: The first day of class helps students learn about what to expect from their instructors and courses. Messaging used by instructors, which varies in content and approach on the first day, shapes classroom social dynamics and can affect subsequent learning in a course. Prior work established the non-content Instructor Talk Framework to describe the language that instructors use to create learning environments, but little is known about the extent to which students detect those messages. In this study, we paired first day classroom observation data with results from student surveys to measure how readily students in introductory STEM courses detect non-content Instructor Talk. RESULTS: To learn more about the instructor and student first day experiences, we studied 11 introductory STEM courses at two different institutions. The classroom observation data were used to characterize course structure and use of non-content Instructor Talk. The data revealed that all instructors spent time discussing their instructional practices, building instructor/student relationships, and sharing strategies for success with their students. After class, we surveyed students about the messages their instructors shared during the first day of class and determined that the majority of students from within each course detected messaging that occurred at a higher frequency. For lower frequency messaging, we identified nuances in what students detected that may help instructors as they plan their first day of class. CONCLUSIONS: For instructors who dedicate the first day of class to establishing positive learning environments, these findings provide support that students are detecting the messages. Additionally, this study highlights the importance of instructors prioritizing the messages they deem most important and giving them adequate attention to more effectively reach students. Setting a positive classroom environment on the first day may lead to long-term impacts on student motivation and course retention. These outcomes are relevant for all students, but in particular for students in introductory STEM courses which are often critical prerequisites for being in a major. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40594-021-00306-y.

Making a First Impression: Exploring What Instructors Do and Say on the First Day of Introductory STEM Courses.

Student impressions formed during the first day of class can impact course satisfaction and performance. Despite its potential importance, little is known about how instructors format the first day of class. Here, we report on observations of the first day of class in 23 introductory science, technology, engineering, and math (STEM) courses. We first described how introductory STEM instructors structure their class time by characterizing topics covered on the first day through inductive coding of class videos. We found that all instructors discussed policies and basic information. However, a cluster analysis revealed two groups of instructors who differed primarily in their level of STEM content coverage. We then coded the videos with the noncontent Instructor Talk framework, which organizes the statements instructors make unrelated to disciplinary content into several categories and subcategories. Instructors generally focused on building the instructor-student relationship and establishing classroom culture. Qualitative analysis indicated that instructors varied in the specificity of their noncontent statements and may have sent mixed messages by making negatively phrased statements with seemingly positive intentions. These results uncovered variation in instructor actions on the first day of class and can help instructors more effectively plan this day by providing messages that set students up for success.

Developmental and molecular characterization of novel staminodes in Aquilegia.

BACKGROUND AND AIMS: The ranunculid model system Aquilegia is notable for the presence of a fifth type of floral organ, the staminode, which appears to be the result of sterilization and modification of the two innermost whorls of stamens. Previous studies have found that the genetic basis for the identity of this new organ is the result of sub- and neofunctionalization of floral organ identity gene paralogues; however, we do not know the extent of developmental and molecular divergence between stamens and staminodes. METHODS: We used histological techniques to describe the development of the Aquilegia coerulea 'Origami' staminode relative to the stamen filament. These results have been compared with four other Aquilegia species and the closely related genera Urophysa and Semiaquilegia. As a complement, RNA sequencing has been conducted at two developmental stages to investigate the molecular divergence of the stamen filaments and staminodes in A. coerulea 'Origami'. KEY RESULTS: Our developmental study has revealed novel features of staminode development, most notably a physical interaction along the lateral margin of adjacent organs that appears to mediate their adhesion. In addition, patterns of abaxial/adaxial differentiation are observed in staminodes but not stamen filaments, including asymmetric lignification of the adaxial epidermis in the staminodes. The comparative transcriptomics are consistent with the observed lignification of staminodes and indicate that stamen filaments are radialized due to overexpression of adaxial identity, while the staminodes are expanded due to the balanced presence of abaxial identity. CONCLUSIONS: These findings suggest a model in which the novel staminode identity programme interacts with the abaxial/adaxial identity pathways to produce two whorls of laterally expanded organs that are highly differentiated along their abaxial/adaxial axis. While the ecological function of Aquilegia staminodes remains to be determined, these data are consistent with a role in protecting the early carpels from herbivory and/or pathogens.

"What Will I Experience in My College STEM Courses?" An Investigation of Student Predictions about Instructional Practices in Introductory Courses.

The instructional practices used in introductory college courses often differ dramatically from those used in high school courses, and dissatisfaction with these practices is cited by students as a prominent reason for leaving science, technology, engineering, and mathematics (STEM) majors. To better characterize the transition to college course work, we investigated the extent to which incoming expectations of course activities differ based on student demographic characteristics, as well as how these expectations align with what students will experience. We surveyed more than 1500 undergraduate students in large introductory STEM courses at three research-intensive institutions during the first week of classes about their expectations regarding how class time would be spent in their courses. We found that first-generation and first-semester students predict less lecture than their peers and that class size had the largest effect on student predictions. We also collected classroom observation data from the courses and found that students generally underpredicted the amount of lecture observed in class. This misalignment between student predictions and experiences, especially for first-generation and first-semester college students and students enrolled in large- and medium-size classes, has implications for instructors and universities as they design curricula for introductory STEM courses with explicit retention goals.

Homologs of LEAFY and UNUSUAL FLORAL ORGANS Promote the Transition From Inflorescence to Floral Meristem Identity in the Cymose Aquilegia coerulea.

Homologs of the transcription factor LEAFY (LFY) and the F-box family member UNUSUAL FLORAL ORGANS (UFO) have been found to promote floral meristem identity across diverse dicot model systems. The lower eudicot model Aquilegia produces cymose inflorescences that are independently evolved from the well-studied cymose models Petunia and tomato. We have previously characterized the expression pattern of the Aquilegia homolog AqLFY but in the current study, we add expression data on the two UFO homologs, AqUFO1 and 2, and conduct virus-induced gene silencing of all the loci. Down-regulation of AqLFY or AqUFO1 and 2 does not eliminate floral meristem identity but, instead, causes the transition from inflorescence to floral identity to become gradual rather than discrete. Inflorescences in down-regulated plants generate several nodes of bract/sepal chimeras and, once floral development does commence, flowers initiate several whorls of sepals before finally producing the wildtype floral whorls. In addition, silencing of AqUFO1/2 appears to specifically impact petal identity and/or the initiation of petal and stamen whorls. In general, however, there is no evidence for an essential role of AqLFY or AqUFO1/2 in transcriptional activation of the B or C gene homologs. These findings highlight differences between deeply divergent dicot lineages in the functional conservation of the floral meristem identity program.