Cultivating cultural capitals in introductory algebra-based physics through reflective journaling.

At a large, diverse, hispanic-serving, master's-granting university, the Alma Project was created to support the rich connections of life experiences of science, technology, engineering, and mathematics (STEM) students that come from racially diverse backgrounds through reflective journaling. Utilizing frameworks in ethnic studies and social psychology, the Alma Project aims to make learning STEM inclusive by affirming the intersectional identities and cultural wealth that students bring into STEM classrooms. Approximately once per month students who participate in the Alma Project spend 5-10 min at the beginning of class responding to questions designed to affirm their values and purpose for studying STEM in college. Students then spend time in class sharing their responses with their peers, to the extent that they feel comfortable, including common struggles and successes in navigating through college and STEM spaces. For this study, we analyze 180 reflective journaling essays of students enrolled in General Physics I, an algebra-based introductory physics course primarily for life science majors. Students were enrolled in a required lab, a self-selected community-based learning program (Supplemental Instruction), or in a small number of instances, both. Using the community cultural wealth framework to anchor our analysis, we identified 11 cultural capitals that students often expressed within these physics spaces. Students in both populations frequently expressed aspirational, attainment, and navigational capital, while expressions of other cultural capitals, such as social capital, differ in the two populations. Our findings suggest that students bring rich and diverse perspectives into physics classrooms when asked to reflect about their lived experiences. Moreover, our study provides evidence that reflective journaling can be used as an asset-based teaching tool. By using reflective journaling in physics spaces, recognizing students' assets has the potential for physics educators to leverage students' lived experiences, goals, and values to make physics learning more meaningful and engaging.

The Influence of Microaffirmations on Undergraduate Persistence in Science Career Pathways.

The present studies aimed to advance the measurement and understanding of microaffirmation kindness cues and assessed how they related to historically underrepresented (HU) and historically overrepresented (HO) undergraduate student persistence in science-related career pathways. Study 1 developed and tested the dimensionality of a new Microaffirmations Scale. Study 2 confirmed the two-factor structure of the Microaffirmations Scale and demonstrated that the scale possessed measurement invariance across HU and HO students. Further, the scale was administered as part of a longitudinal design spanning 9 months, with results showing that students' reported microaffirmations did not directly predict higher intentions to persist in science-related career pathways 9 months later. However, scientific self-efficacy and identity, measures of student integration into the science community, mediated this relationship. Overall, our results demonstrated that microaffirmations can be measured in an academic context and that these experiences have predictive value when they increase students' integration into their science communities, ultimately resulting in greater intentions to persist 9 months later. Researchers and practitioners can use the Microaffirmations Scale for future investigations to increase understanding of the positive contextual factors that can ultimately help reduce persistence gaps in science, technology, engineering, and mathematics degree attainment.

The Influence of Affirming Kindness and Community on Broadening Participation in STEM Career Pathways.

The United States' inability to achieve equitable workforce development in science, technology, engineering, and mathematics (STEM) career pathways is well-recognized and has been attributed to the poor retention of a diverse stream of students in academia. Social science theory and research provide evidence that social contextual variables-specifically kindness cues affirming social inclusion-influence chronic underrepresentation of some groups within STEM career pathways. Review of the literature suggests that the current STEM academic context does not consistently provide cues that affirm social inclusion to all members of the academic population, and that policies that address this disparity are essential to broadening STEM workforce development in the United States.

Enabling full representation in science: the San Francisco BUILD project's agents of change affirm science skills, belonging and community.

BACKGROUND: The underrepresentation of minority students in the sciences constrains innovation and productivity in the U.S. The SF BUILD project mission is to remove barriers to diversity by taking a "fix the institution" approach rather than a "fix the student" one. SF BUILD is transforming education, research, training, and mentoring at San Francisco State University, a premiere public university that primarily serves undergraduates and ethnic minority students. It boasts a large number of faculty members from underrepresented groups (URGs), including many of the project leaders. These leaders collaborate with faculty at the University of California San Francisco (UCSF), a world-class medical research institution, to implement SF BUILD. KEY HIGHLIGHTS: Together, the campus partners are committed to creating intellectually safe and affirming environments grounded in the Signaling Affirmation for Equity (SAFE) model, which is based on robust psychosocial evidence on stereotype threat and its consequences. The SAFE model dictates a multilevel approach to increasing intent to pursue a biomedical career, persistence in STEM fields, and productivity (e.g. publications, presentations, and grants) by implementing transformative activities at the institutional, faculty, and student levels. These activities (1) increase knowledge of the stereotype threat phenomenon; (2) affirm communal and altruistic goals of students and faculty to "give back" to their communities in classrooms and research activities; and (3) establish communities of students, faculty and administrators as "agents of change." Agents of change are persons committed to establishing and maintaining SAFE environments. In this way, SF BUILD advances the national capacity to address biomedical questions relevant to communities of color by enabling full representation in science. IMPLICATIONS: This chapter describes the theoretical and historical context that drive the activities, research and evaluation of the SF BUILD project, and highlights attributes that other institutions can use for institutional change. While this paper is grounded in psychosocial theory, it also provides practical solutions for broadening participation.

Dissecting the active site of the collagenolytic cathepsin L3 protease of the invasive stage of Fasciola hepatica.

BACKGROUND: A family of secreted cathepsin L proteases with differential activities is essential for host colonization and survival in the parasitic flatworm Fasciola hepatica. While the blood feeding adult secretes predominantly FheCL1, an enzyme with a strong preference for Leu at the S2 pocket of the active site, the infective stage produces FheCL3, a unique enzyme with collagenolytic activity that favours Pro at P2. METHODOLOGY/PRINCIPAL FINDINGS: Using a novel unbiased multiplex substrate profiling and mass spectrometry methodology (MSP-MS), we compared the preferences of FheCL1 and FheCL3 along the complete active site cleft and confirm that while the S2 imposes the greatest influence on substrate selectivity, preferences can be indicated on other active site subsites. Notably, we discovered that the activity of FheCL1 and FheCL3 enzymes is very different, sharing only 50% of the cleavage sites, supporting the idea of functional specialization. We generated variants of FheCL1 and FheCL3 with S2 and S3 residues by mutagenesis and evaluated their substrate specificity using positional scanning synthetic combinatorial libraries (PS-SCL). Besides the rare P2 Pro preference, FheCL3 showed a distinctive specificity at the S3 pocket, accommodating preferentially the small Gly residue. Both P2 Pro and P3 Gly preferences were strongly reduced when Trp67 of FheCL3 was replaced by Leu, rendering the enzyme incapable of digesting collagen. In contrast, the inverse Leu67Trp substitution in FheCL1 only slightly reduced its Leu preference and improved Pro acceptance in P2, but greatly increased accommodation of Gly at S3. CONCLUSIONS/SIGNIFICANCE: These data reveal the significance of S2 and S3 interactions in substrate binding emphasizing the role for residue 67 in modulating both sites, providing a plausible explanation for the FheCL3 collagenolytic activity essential to host invasion. The unique specificity of FheCL3 could be exploited in the design of specific inhibitors selectively directed to specific infective stage parasite proteinases.

Characterization of gut-associated cathepsin D hemoglobinase from tick Ixodes ricinus (IrCD1).

To identify the gut-associated tick aspartic hemoglobinase, this work focuses on the functional diversity of multiple Ixodes ricinus cathepsin D forms (IrCDs). Out of three encoding genes representing Ixodes scapularis genome paralogs, IrCD1 is the most distinct enzyme with a shortened propeptide region and a unique pattern of predicted post-translational modifications. IrCD1 gene transcription is induced by tick feeding and is restricted to the gut tissue. The hemoglobinolytic role of IrCD1 was further supported by immunolocalization of IrCD1 in the vesicles of tick gut cells. Properties of recombinantly expressed rIrCD1 are consistent with the endo-lysosomal environment because the zymogen is autoactivated and remains optimally active in acidic conditions. Hemoglobin cleavage pattern of rIrCD1 is identical to that produced by the native enzyme. The preference for hydrophobic residues at the P1 and P1' position was confirmed by screening a novel synthetic tetradecapeptidyl substrate library. Outside the S1-S1' regions, rIrCD1 tolerates most amino acids but displays a preference for tyrosine at P3 and alanine at P2'. Further analysis of the cleavage site location within the peptide substrate indicated that IrCD1 is a true endopeptidase. The role in hemoglobinolysis was verified with RNAi knockdown of IrCD1 that decreased gut extract cathepsin D activity by >90%. IrCD1 was newly characterized as a unique hemoglobinolytic cathepsin D contributing to the complex intestinal proteolytic network of mainly cysteine peptidases in ticks.