An Equity-Focused Redesign of an Introductory Organismal Biology Lab Course To Develop Foundational Scientific Practices.

Laboratory courses can serve as important avenues to equitably support introductory biology students to develop foundational scientific literacy skills while experiencing the authentic research process. We present a model for an equity-focused redesign of an introductory organismal biology laboratory course at a teaching institution with limited research infrastructure. We incorporated elements of inquiry, structure, and climate into our three redesigned course components: weekly research investigations, skill-building assignments, and student-designed group projects. Students were trained in the research process through weekly experiments using locally relevant model organisms, collecting and analyzing novel data and writing brief results sections in the conventions of a research journal article. Student groups then collaborated to complete a student-designed research project and poster presentation using one of the model organisms. Through weekly inquiry labs and practice in skill-building assignments, most students in the sample mastered skills in analyzing, graphing, and writing about experimental results. Notably, students mastered skills that were practiced more frequently throughout the lab course, demonstrating the value of repeated and scaffolded practice. Students reported significant gains in self-efficacy and science identity, as well as sense of project ownership. Student gains were influenced by instructor but not their major or the semester in which they took the course, and growth occurred across students regardless of their incoming score on the presemester survey. This intentional course design model, combined with consistent expectations for instructors across multiple sections, has the potential to equitably support students with a range of prior knowledge and experiences to make meaningful gains in science literacy skills during an introductory semester.

Increased Scaffolding and Inquiry in an Introductory Biology Lab Enhance Experimental Design Skills and Sense of Scientific Ability.

We present a model for the process of redesigning the laboratory curriculum in Introductory Organismal Biology to increase opportunities for meaningful inquiry and increase student recognition of their scientific skill development. We created scaffolded modules and assignments to allow students to build and practice key skills in experimental design, data analysis, and scientific writing. Using the Tool for Interrelated Experimental Design, we showed significantly higher gains in experimental design scores in the redesigned course and a more consistent pattern of gains across a range of initial student scores compared with the original format. Students who completed the redesigned course rated themselves significantly higher in experimental design, data collection, and data analysis skills compared with students in the original format. Scores on the Laboratory Course Activity Survey were high for both formats and did not significantly differ. However, on written course evaluations, students in the redesigned course were more likely to report that they engaged in "real science" and their "own experiments." They also had increased recognition of their specific analytical and writing skill development. Our results demonstrate that intentional, scaffolded instruction using inquiry modules can increase experimental design skills and sense of scientific ability in an introductory biology course.

First-Day Info Sheets: A Tool to Prompt Semester-Long Inclusive Teaching.

What faculty do and say on the first day of class is crucial to establishing and maintaining an inclusive learning environment for the duration of the semester. First-day information sheets ("info sheets") are commonly used by instructors. By making simple modifications to this tool, we can gather more information about the goals and experiences of our students, the lives of our students outside of our classroom, and how our students' lives may impact their engagement with the course material and course structure. We can also use this information to actively highlight to students that their full selves (names, pronouns, background) belong in our biology classroom. We provide a set of prompts and suggested steps, rooted in the scholarly literature, to encourage and facilitate faculty use of info-sheets as a valuable tool to inform semester-long inclusive teaching efforts.

Development of a Tool to Assess Interrelated Experimental Design in Introductory Biology.

Designing experiments and applying the process of science are core competencies for many introductory courses and course-based undergraduate research experiences (CUREs). However, experimental design is a complex process that challenges many introductory students. We describe the development of a tool to assess interrelated experimental design (TIED) in an introductory biology lab course. We describe the interrater reliability of the tool, its effectiveness in detecting variability and growth in experimental-design skills, and its adaptability for use in various contexts. The final tool contained five components, each with multiple criteria in the form of a checklist such that a high-quality response-in which students align the different components of their experimental design-satisfies all criteria. The tool showed excellent interrater reliability and captured the full range of introductory-student skill levels, with few students hitting the assessment ceiling or floor. The scoring tool detected growth in student skills from the beginning to the end of the semester, with significant differences between pre- and post-assessment scores for the Total Score and for the Data Collection and Observations component scores. This authentic assessment task and scoring tool provide meaningful feedback to instructors about the strengths, gaps, and growth in introductory students' experimental-design skills and can be scored reliably by multiple instructors. The TIED can also be adapted to a number of experimental-design prompts and learning objectives, and therefore can be useful for a variety of introductory courses and CUREs.

High costs of infection: Alphavirus infection reduces digestive function and bone and feather growth in nestling house sparrows (Passer domesticus).

Increasingly, ecoimmunology studies aim to use relevant pathogen exposure to examine the impacts of infection on physiological processes in wild animals. Alphaviruses are arthropod-borne, single-stranded RNA (ssRNA) viruses ("arboviruses") responsible for millions of cases of human illnesses each year. Buggy Creek virus (BCRV) is a unique alphavirus that is transmitted by a cimicid insect, the swallow bug, and is amplified in two avian species: the house sparrow (Passer domesticus) and the cliff swallow (Petrochelidon pyrrhonota). BCRV, like many alphaviruses, exhibits age-dependent susceptibility where the young are most susceptible to developing disease and exhibit a high mortality rate. However, alphavirus disease etiology in nestling birds is unknown. In this study, we infected nestling house sparrows with Buggy Creek virus and measured virological, pathological, growth, and digestive parameters following infection. Buggy Creek virus caused severe encephalitis in all infected nestlings, and the peak viral concentration in brain tissue was over 34 times greater than any other tissue. Growth, tissue development, and digestive function were all significantly impaired during BCRV infection. However, based on histopathological analysis performed, this impairment does not appear to be the result of direct tissue damage by the virus, but likely caused by encephalitis and neuronal invasion and impairment of the central nervous system. This is the first study to examine the course of alphavirus diseases in nestling birds and these results will improve our understanding of age-dependent infections of alphaviruses in vertebrate hosts.

Phagocytic Receptors Activate Syk and Src Signaling during Borrelia burgdorferi Phagocytosis.

Phagocytosis of the Lyme disease-causing pathogen Borrelia burgdorferi has been shown to be important for generating an inflammatory response to the pathogen. As a result, understanding the mechanisms of phagocytosis has been an area of great interest in the field of Lyme disease. Several cell surface receptors that participate in B. burgdorferi phagocytosis have been reported, including the scavenger receptor MARCO and integrin α3ß1. We sought to define the mechanisms by which these receptors mediate phagocytosis and to identify signaling pathways activated downstream of these receptors upon contact with B. burgdorferi We identified both Syk and Src signaling pathways as ones that participate in B. burgdorferi phagocytosis and the resulting cytokine activation. In our studies, we found that both MARCO and integrin ß1 play a role in the activation of the Src kinase pathway. However, only integrin ß1 participates in the activation of Syk. Interestingly, the integrin activates Syk without the help of the signaling adaptor Dap12 or FcRγ. Thus, we report that multiple pathways participate in B. burgdorferi internalization and that different cell surface receptors act simultaneously in cooperation and independently to mediate phagocytosis.

Toward Inclusive STEM Classrooms: What Personal Role Do Faculty Play?

Private and public policies are increasingly aimed at supporting efforts to broaden participation of a diverse body of students in higher education. Unfortunately, this increase in student diversity does not always occur alongside changes in institutional culture. Unexamined biases in institutional culture can prevent diverse students from thriving and persisting in science, technology, engineering, and mathematics (STEM) fields. Given the daily personal interactions that faculty have with students, we suggest that individual educators have the opportunity, and responsibility, to improve the retention and persistence of diverse students. However, in our experience, faculty professional development programs often limit discussions of diversity to "comfortable" topics (such as learning styles) and miss opportunities to explore deeper issues related to faculty privilege, implicit bias, and cues for stereotype threat that we all bring to the classroom. In this essay, we present a set of social science concepts that we can extend to our STEM courses to inform our efforts at inclusive excellence. We have recommended strategies for meaningful reflection and professional development with respect to diversity and inclusion, and aim to empower faculty to be change agents in their classrooms as a means to broadening participation in STEM fields.

Adaptor Protein-3-Mediated Trafficking of TLR2 Ligands Controls Specificity of Inflammatory Responses but Not Adaptor Complex Assembly.

Innate immune engagement results in the activation of host defenses that produce microbe-specific inflammatory responses. A long-standing interest in the field of innate immunity is to understand how varied host responses are generated through the signaling of just a limited number of receptors. Recently, intracellular trafficking and compartmental partitioning have been identified as mechanisms that provide signaling specificity for receptors by regulating signaling platform assembly. We show that cytokine activation as a result of TLR2 stimulation occurs at different intracellular locations and is mediated by the phagosomal trafficking molecule adaptor protein-3 (AP-3). AP-3 is required for trafficking TLR2 purified ligands or the Lyme disease causing bacterium, Borrelia burgdorferi, to LAMP-1 lysosomal compartments. The presence of AP-3 is necessary for the activation of cytokines such as IL-6 but not TNF-α or type I IFNs, suggesting induction of these cytokines occurs from a different compartment. Lack of AP-3 does not interfere with the recruitment of TLR signaling adaptors TRAM and MyD88 to the phagosome, indicating that the TLR-MyD88 signaling complex is assembled at a prelysosomal stage and that IL-6 activation depends on proper localization of signaling molecules downstream of MyD88. Finally, infection of AP-3-deficient mice with B. burgdorferi resulted in altered joint inflammation during murine Lyme arthritis. Our studies further elucidate the effects of phagosomal trafficking on tailoring immune responses in vitro and in vivo.

Impacts of short-term food restriction on immune development in altricial house sparrow nestlings.

Food limitation is a common ecological scenario for nestling altricial birds, and reductions in growth and maintenance have been observed in resource-limited nestlings. Substantial development of the immune system occurs during the nestling period, yet the resource dependence of this immune development is understudied. We examined constitutive immune system development as well as acute-phase responses to lipopolysaccharide (LPS) injection after 48 h of food restriction in house sparrows at 7 and 13 d posthatch. We also examined nestlings that were restricted early (5-7 d) but refed and tested at 13 d posthatch to determine whether altered immune function and growth early in the nestling period were recovered upon return to adequate resource supply. Induced acute-phase protein response was reduced in food-restricted birds, yet no lasting reductions in acute-phase protein levels were observed in previously restricted nestlings that were challenged with LPS after refeeding. Food restriction did not significantly impact constitutive levels of complement-mediated lysis or circulating IgY antibodies. As a comparator to immune measures, we found that organ and tarsus size, as well as muscle size and citrate synthase enzyme activity (an index of muscle cellular aerobic capacity), were significantly reduced in food-restricted nestlings. Reductions in flight muscle mass and function persisted in birds refed after early food restriction, which may have contributed to persistent body temperature reductions observed in refed birds.

Ontogeny of adaptive antibody response to a model antigen in captive altricial zebra finches.

Based on studies from the poultry literature, all birds are hypothesized to require at least 4 weeks to develop circulating mature B-cell lineages that express functionally different immunoglobulin specificities. However, many altricial passerines fledge at adult size less than four weeks after the start of embryonic development, and therefore may experience a period of susceptibility during the nestling and post-fledging periods. We present the first study, to our knowledge, to detail the age-related changes in adaptive antibody response in an altricial passerine. Using repeated vaccinations with non-infectious keyhole limpet hemocyanin (KLH) antigen, we studied the ontogeny of specific adaptive immune response in altricial zebra finches Taeniopygia guttata. Nestling zebra finches were first injected at 7 days (7d), 14 days (14d), or 21 days post-hatch (21d) with KLH-adjuvant emulsions, and boosted 7 days later. Adults were vaccinated in the same manner. Induced KLH-specific IgY antibodies were measured using ELISA. Comparisons within age groups revealed no significant increase in KLH-specific antibody levels between vaccination and boost in 7d birds, yet significant increases between vaccination and boost were observed in 14d, 21d, and adult groups. There was no significant difference among age groups in KLH antibody response to priming vaccination, yet KLH antibody response post-boost significantly increased with age among groups. Post-boost antibody response in all nestling age groups was significantly lower than in adults, indicating that mature adult secondary antibody response level was not achieved in zebra finches prior to fledging (21 days post-hatch in zebra finches). Findings from this study contribute fundamental knowledge to the fields of developmental immunology and ecological immunology and strengthen the utility of zebra finches as a model organism for future studies of immune ontogeny.

Growth and development of house sparrows (Passer domesticus) in response to chronic food restriction throughout the nestling period.

Birds have evolved phenotypic plasticity in growth and developmental patterns in order to respond to fluctuating environmental conditions and to mitigate the impact of poor feeding on fitness. Chronic food shortage can occur during chick development in the wild, and the responses of altricial birds have not been thoroughly studied. House sparrow (Passer domesticus) nestlings were raised in the laboratory on age-specific meal sizes (controls) or meal sizes 25% less than age-specific amounts (food-restricted) and analyzed at 6, 9 and 12 days post-hatch for differences in growth and development. Food-restricted birds had significantly reduced body mass and body temperature, but skeletal growth was maintained with respect to controls. Muscle mass was significantly reduced and muscle water content was slightly, though not significantly, higher in food-restricted birds, which may reflect slight developmental immaturity. Assimilation organ masses, summed enzymatic capacity of the intestine and lipid content of the liver were significantly reduced in food-restricted birds. Findings from this study indicate that altricial birds experiencing chronic, moderate food restriction throughout the nestling period may allocate resources to structural growth through energy-saving reductions in mass of assimilation organs and body temperature.