Advancing Undergraduate Laboratory Education Using Non-Model Insect Species.

Over the past decade, laboratory courses have made a fundamental shift to inquiry-based modules and authentic research experiences. In many cases, these research experiences emphasize addressing novel research questions. Insects are ideal for inquiry-based undergraduate laboratory courses because research on insects is not limited by regulatory, economic, and logistical constraints to the same degree as research on vertebrates. While novel research questions could be pursued with model insect species (e.g., Drosophila, Tribolium), the opportunities presented by non-model insects are much greater, as less is known about non-model species. We review the literature on the use of non-model insect species in laboratory education to provide a resource for faculty interested in developing new authentic inquiry-based laboratory modules using insects. Broader use of insects in undergraduate laboratory education will support the pedagogical goals of increased inquiry and resesarch experiences while at the same time fostering increased interest and research in entomology.

The Relationship between Perceptions of Instructional Practices and Student Self-Efficacy In Guided-Inquiry Laboratory Courses.

Science self-efficacy, a student's confidence in being able to perform scientific practices, interacts with science identity and outcomes expectations, leading to improved performance in science courses, persistence in science majors, and ultimately, the pursuit of advanced training in the sciences. Inquiry-based laboratory courses have been shown to improve undergraduate student self-efficacy, but the mechanisms involved and specific components of instructional practices that lead to improved self-efficacy are not clear. In the current study, we determined whether student and faculty perceptions of laboratory instructional practices (scientific synthesis, science process skills, and instructor-directed teaching) were related to postsemester self-efficacy across 19 guided-inquiry laboratory courses from 11 different institutions. Self-efficacy related to science literacy increased significantly from the beginning of the semester to the end of the semester. Variation in individual student perceptions of instructional practices within a course were significantly related to differences in student self-efficacy at the end of the semester, but not average student perceptions or faculty perceptions of their own practices across courses. The importance of individual student perceptions suggests that faculty should engage with students during curricular development. Furthermore, faculty need to use noncontent talk to reinforce the science practices students are engaging in during inquiry-based laboratory courses.

The Bean Beetle Microbiome Project: A Course-Based Undergraduate Research Experience in Microbiology.

Course-based undergraduate research experiences (CUREs) are an effective means of transforming the learning and teaching of science by involving students in the scientific process. The potential importance of the microbiome in shaping both environmental health and disease makes investigations of microbiomes an excellent teaching tool for undergraduate microbiology. Here, we present a CURE based on the microbiome of the bean beetle (Callosobruchus maculatus), a model system for undergraduate laboratory education. Despite the extensive research literature on bean beetles, little is known about their microbiome, making them an ideal system for a discovery-based CURE. In the CURE, students acquire microbiological technical skills by characterizing both culturable and unculturable members of the beetle gut-microbial community. Students plate beetle gut homogenates on different media, describe the colonies that are formed to estimate taxonomic diversity, extract DNA from colonies of interest, PCR amplify the16S rRNA gene for Sanger sequencing, and use the NCBI-nBLAST database to taxonomically classify sequences. Additionally, students extract total DNA from beetle gut homogenates for high-throughput paired-end sequencing and perform bioinformatic and statistical analyses of bacterial communities using a combination of open-access data processing software. Each activity allows students to engage with studies of microbiomes in a real-world context, to apply concepts and laboratory techniques to investigate either student or faculty-driven research questions, and to gain valuable experiences working with large high-throughput datasets. The CURE is designed such that it can be implemented over either 6-weeks (half semester) or 12-weeks (full semester), allowing for flexibility within the curriculum. Furthermore, student-generated data from the CURE (including bacterial colony phenotypic data, full-length 16S rRNA gene sequences from cultured isolates, and bacterial community sequences from gut homogenates) has been compiled in a continuously curated open-access database on the Bean Beetle Microbiome Project website, facilitating the generation of broader research questions across laboratory classrooms.

Genomic diversity of bacteriophages infecting Microbacterium spp.

The bacteriophage population is vast, dynamic, old, and genetically diverse. The genomics of phages that infect bacterial hosts in the phylum Actinobacteria show them to not only be diverse but also pervasively mosaic, and replete with genes of unknown function. To further explore this broad group of bacteriophages, we describe here the isolation and genomic characterization of 116 phages that infect Microbacterium spp. Most of the phages are lytic, and can be grouped into twelve clusters according to their overall relatedness; seven of the phages are singletons with no close relatives. Genome sizes vary from 17.3 kbp to 97.7 kbp, and their G+C% content ranges from 51.4% to 71.4%, compared to ~67% for their Microbacterium hosts. The phages were isolated on five different Microbacterium species, but typically do not efficiently infect strains beyond the one on which they were isolated. These Microbacterium phages contain many novel features, including very large viral genes (13.5 kbp) and unusual fusions of structural proteins, including a fusion of VIP2 toxin and a MuF-like protein into a single gene. These phages and their genetic components such as integration systems, recombineering tools, and phage-mediated delivery systems, will be useful resources for advancing Microbacterium genetics.

A Model for an Intensive Hands-On Faculty Development Workshop To Foster Change in Laboratory Teaching.

Faculty development workshops are frequently used to bring about change in faculty teaching. Yet, the characteristics of successful faculty professional development in the context of laboratory teaching are unclear. In this Perspective, we describe our approach to intensive hands-on faculty development workshops for fostering change in laboratory teaching and present evidence for the effectiveness of the approach. The outcomes from our workshops and feedback from past participants support the following recommendations: 1) faculty should attend workshops in teams from their institutions, 2) workshops should allow participants to develop curricula that can be implemented with relatively little additional work after the workshop, 3) workshops should allow faculty time to "work" on tangible products and should involve hands-on activities, 4) workshops should be of sufficient duration to allow for faculty to develop expertise and tangible products but short enough that faculty do not "burn out," and 5) a structure for ongoing and systematic follow-up with participants is essential.

Laboratory Courses with Guided-Inquiry Modules Improve Scientific Reasoning and Experimental Design Skills for the Least-Prepared Undergraduate Students.

Past studies on the differential effects of active learning based on students' prior preparation and knowledge have been mixed. The purpose of the present study was to ask whether students with different levels of prior preparation responded differently to laboratory courses in which a guided-inquiry module was implemented. In the first study, we assessed student scientific reasoning skills, and in the second we assessed student experimental design skills. In each course in which the studies were conducted, student gains were analyzed by pretest quartiles, a measure of their prior preparation. Overall, student scientific reasoning skills and experimental design skills did not improve pretest to posttest. However, when divided into quartiles based on pretest score within each course, students in the lowest quartile experienced significant gains in both studies. Despite the significant gains observed among students in the lowest quartile, significant posttest differences between lowest and highest quartiles were observed in both scientific reasoning skills and experimental design skills. Nonetheless, these findings suggest that courses with guided-inquiry laboratory activities can foster the development of basic scientific reasoning and experimental design skills for students who are least prepared across a range of course levels and institution types.

Multi-Institutional, Multidisciplinary Study of the Impact of Course-Based Research Experiences.

Numerous national reports have called for reforming laboratory courses so that all students experience the research process. In response, many course-based research experiences (CREs) have been developed and implemented. Research on the impact of these CREs suggests that student benefits can be similar to those of traditional apprentice-model research experiences. However, most assessments of CREs have been in individual courses at individual institutions or across institutions using the same CRE model. Furthermore, which structures and components of CREs result in the greatest student gains is unknown. We explored the impact of different CRE models in different contexts on student self-reported gains in understanding, skills, and professional development using the Classroom Undergraduate Research Experience (CURE) survey. Our analysis included 49 courses developed and taught at seven diverse institutions. Overall, students reported greater gains for all benefits when compared with the reported national means for the Survey of Undergraduate Research Experiences (SURE). Two aspects of these CREs were associated with greater student gains: 1) CREs that were the focus of the entire course or that more fully integrated modules within a traditional laboratory and 2) CREs that had a higher degree of student input and results that were unknown to both students and faculty.

Genome Sequences of Four Subcluster L2 Mycobacterium Phages, Finemlucis, Miley16, Wilder, and Zakai.

Four subcluster L2 mycobacteriophages, Finemlucis, Miley16, Wilder, and Zakai, that infect Mycobacterium smegmatis mc2155 were isolated. The four phages are closely related to each other and code for 12 to 14 tRNAs and 130 to 132 putative protein-coding genes, including tyrosine integrases, cro, immunity repressors, and excise genes involved in the establishment of lysogeny.

Social interactions tune aggression and stress responsiveness in a territorial cichlid fish (Archocentrus nigrofasciatus).

We examined the relative influences of pre-fight housing condition, contest intensity, and contest outcome in modulating post-fight stress hormone concentrations in territorial male convict cichlids (Archocentrus nigrofasciatus). Individuals were housed either in isolation or in semi-natural communal tanks. Pairs of male cichlids that differed considerably in body mass were selected from the same housing regime. Pre-fight water-borne cortisol levels were obtained before allowing the dyad to interact until contest resolution, after which time post-fight cortisol levels were obtained from the winner and loser. There were no outcome-related differences in post-fight cortisol concentrations following escalated or non-escalated contests, a result that held true for both housing regimes. Pre-fight cortisol levels were significantly higher than post-fight cortisol levels, suggesting that initial confinement in a beaker for the water-borne hormone samples was a stressor, but that the animals acclimated quickly to confinement. Fights involving previously isolated participants were significantly more intense than those involving group-housed animals, which we explain as being a function of established relationships between social isolation, heightened acute cortisol responsiveness, and the expression of excessive aggressive behavior. Only group-housed losers demonstrated the ability to modulate aggression or hypothalamic-pituitary-interrenal (HPI) activity in a graded fashion to acute increases in cortisol or changes in contest intensity, respectively. We discuss a variety of factors that could disrupt the ability of isolates to appropriately modulate interactions between social behavior and the HPI axis, and we examine a number of functional hypotheses underlying the sensitivity of group-housed losers to changes in contest dynamics.

Alternative Realities: Faculty and Student Perceptions of Instructional Practices in Laboratory Courses.

Curricular reform efforts depend on our ability to determine how courses are taught and how instructional practices affect student outcomes. In this study, we developed a 30-question survey on inquiry-based learning and assessment in undergraduate laboratory courses that was administered to 878 students in 54 courses (41 introductory level and 13 upper level) from 20 institutions (four community colleges, 11 liberal arts colleges, and five universities, of which four were minority-serving institutions). On the basis of an exploratory factor analysis, we defined five constructs: metacognition, feedback and assessment, scientific synthesis, science process skills, and instructor-directed teaching. Using our refined survey of 24 items, we compared student and faculty perceptions of instructional practices both across courses and across instructors. In general, faculty and student perceptions were not significantly related. Although mean perceptions were often similar, faculty perceptions were more variable than those of students, suggesting that faculty may have more nuanced views than students. In addition, student perceptions of some instructional practices were influenced by their previous experience in laboratory courses and their self-efficacy. As student outcomes, such as learning gains, are ultimately most important, future research should examine the degree to which faculty and student perceptions of instructional practices predict student outcomes in different contexts.

The gall of subordination: changes in gall bladder function associated with social stress.

Diverse physiological and behavioural mechanisms allow animals to effectively deal with stressors, but chronic activation of the stress axis can have severe consequences. We explored the effects of chronic social stress on agonistic behaviour and gall bladder function, a critical but widely neglected component of stress-induced gastrointestinal dysfunction. Prolonged cohabitation with dominant individuals elicited behavioural modifications and dramatically increased bile retention in subordinate convict cichlid fish (Archocentrus nigrofasciatum). The key predictor of gall bladder hypertrophy was social subordination rather than status-related differences in food intake or body size. Stress-induced inhibition of gall bladder emptying could affect energy assimilation such that subordinate animals would not be able to effectively convert energy-rich food into mass gain. These results parallel changes in gall bladder function preceding cholesterol gallstone formation in humans and other mammals. Thus, social stress may be an important diagnostic criterion in understanding pathologies associated with gall bladder dysfunction.

SEASONAL VARIATION IN SEXUAL SELECTION IN THE MOTTLED SCULPIN.

Seasonal variation in sexual and natural selection in male mottled sculpins (Cottus bairdi) can be evaluated by calculating selection differentials, which measure the magnitude of phenotypic change resulting from selection, and by calculating indices of the opportunity for selection, which indicate the potential for phenotypic selection in a given interval. Selection differentials are high at the beginning of the breeding season and decline throughout the breeding season. The magnitude and direction of selection differentials depend on when spawning occurs and are independent of the size or age of the females that spawn. Annual selection differentials due to differences in mating success (female choice) are nearly constant between years. Annual selection differentials associated with hatching success are variable. Opportunities for selection (I = fitness variance/[mean fitness]2 ) show clear seasonal patterns. They are highest at the beginning and at the end of the spawning season. However, this variation is dependent on the mean used to calculate I, and hence variation in I values does not indicate a significant change in the variance of male fitness.