42. Male and Female Differences Regarding Buffers to STEM Fields

STEM (Science, Technology, Engineering, and Mathematics) fields are dominated by males, with societal norms discouraging many women from pursuing a career in STEM. Women in the STEM fields benefit from buffers that mediate the negative effects of discrimination. In our pilot study, we found that playing video games with a romantic partner served as a buffer for female gamers, facilitating their continued play. Understanding male attitudes towards female gamers helps to identify additional buffers and potential ramifications. Our current project empirically explored the male opinion of female gamers and its effect on women’s decision to enter into the STEM fields. We hypothesized that male participants would rate women as less accomplished players, refer to them as weak, and expect women to lack competitiveness. These negative expectations have the potential to influence women’s decisions to pursue STEM careers, specifically game design and programming. Data were collected using an online survey taken by 204 undergraduate males, 300 Caucasian women and 300 minority women. We assessed the participants’ reactions to discrimination and harassment, likelihood to enter a STEM field, and opinions of female gamers. We found that male gamers displayed discriminatory, sexist beliefs towards female gamers which contribute to similar perceptions about the prevalence of harassment in online gaming. Our results explore the link between these beliefs and the likelihood of female gamers pursuing STEM careers. Our study raises awareness of the lack of female presence in STEM fields and explains this deficiency by discerning the male perspective while examining potential buffers. Keywords: Video games, gamers, STEM, discrimination, prejudice, programming, buffers, barriers, sexis

Cas9 interrogates DNA in discrete steps modulated by mismatches and supercoiling.

The CRISPR-Cas9 nuclease has been widely repurposed as a molecular and cell biology tool for its ability to programmably target and cleave DNA. Cas9 recognizes its target site by unwinding the DNA double helix and hybridizing a 20-nucleotide section of its associated guide RNA to one DNA strand, forming an R-loop structure. A dynamic and mechanical description of R-loop formation is needed to understand the biophysics of target searching and develop rational approaches for mitigating off-target activity while accounting for the influence of torsional strain in the genome. Here we investigate the dynamics of Cas9 R-loop formation and collapse using rotor bead tracking (RBT), a single-molecule technique that can simultaneously monitor DNA unwinding with base-pair resolution and binding of fluorescently labeled macromolecules in real time. By measuring changes in torque upon unwinding of the double helix, we find that R-loop formation and collapse proceed via a transient discrete intermediate, consistent with DNA:RNA hybridization within an initial seed region. Using systematic measurements of target and off-target sequences under controlled mechanical perturbations, we characterize position-dependent effects of sequence mismatches and show how DNA supercoiling modulates the energy landscape of R-loop formation and dictates access to states competent for stable binding and cleavage. Consistent with this energy landscape model, in bulk experiments we observe promiscuous cleavage under physiological negative supercoiling. The detailed description of DNA interrogation presented here suggests strategies for improving the specificity and kinetics of Cas9 as a genome engineering tool and may inspire expanded applications that exploit sensitivity to DNA supercoiling

Quantifying engineered nanomaterial toxicity: comparison of common cytotoxicity and gene expression measurements

BACKGROUND: When evaluating the toxicity of engineered nanomaterials (ENMS) it is important to use multiple bioassays based on different mechanisms of action. In this regard we evaluated the use of gene expression and common cytotoxicity measurements using as test materials, two selected nanoparticles with known differences in toxicity, 5 nm mercaptoundecanoic acid (MUA)-capped InP and CdSe quantum dots (QDs). We tested the effects of these QDs at concentrations ranging from 0.5 to 160 µg/mL on cultured normal human bronchial epithelial (NHBE) cells using four common cytotoxicity assays: the dichlorofluorescein assay for reactive oxygen species (ROS), the lactate dehydrogenase assay for membrane viability (LDH), the mitochondrial dehydrogenase assay for mitochondrial function, and the Comet assay for DNA strand breaks. RESULTS: The cytotoxicity assays showed similar trends when exposed to nanoparticles for 24 h at 80 µg/mL with a threefold increase in ROS with exposure to CdSe QDs compared to an insignificant change in ROS levels after exposure to InP QDs, a twofold increase in the LDH necrosis assay in NHBE cells with exposure to CdSe QDs compared to a 50% decrease for InP QDs, a 60% decrease in the mitochondrial function assay upon exposure to CdSe QDs compared to a minimal increase in the case of InP and significant DNA strand breaks after exposure to CdSe QDs compared to no significant DNA strand breaks with InP. High-throughput quantitative real-time polymerase chain reaction (qRT-PCR) data for cells exposed for 6 h at a concentration of 80 µg/mL were consistent with the cytotoxicity assays showing major differences in DNA damage, DNA repair and mitochondrial function gene regulatory responses to the CdSe and InP QDs. The BRCA2, CYP1A1, CYP1B1, CDK1, SFN and VEGFA genes were observed to be upregulated specifically from increased CdSe exposure and suggests their possible utility as biomarkers for toxicity. CONCLUSIONS: This study can serve as a model for comparing traditional cytotoxicity assays and gene expression measurements and to determine candidate biomarkers for assessing the biocompatibility of ENMs.1R01GM84702-01 - National Institute of General Medical Science

The Church Bridge Project Focus Group Results: African American Perspectives of Weight Management Programs to Improve Nutrition and Physical Activity Behaviors

Background: The prevalence of obesity is disproportionately high among African Americans in the Southern US. More information is needed about factors that influence participation in nutrition and physical activity programs to promote healthy weight. Objective: The purpose of this study is to explore the weight management perceptions of young to middle aged adult African Americans. Methods: The Church Bridge Project intervention participants were recruited for two focus groups. Qualitative data were recorded, transcribed and a thematic content analysis was conducted to identify major themes. Results: Barriers included technology learning curve/burden and competing priorities. Facilitators included support, limited cost, convenience, and health. Participants perceived the term “weight management” program as overwhelming and defeating. Conclusion: The Church Bridge Project model confirmed social support and disease prevention as key factors for weight management. Further work should substantiate social support as a key factor to guide minority health efforts

Untangling a Cat’s Cradle: Diphacinone, Acetaminophen, Trauma, and Multiple Deaths in a Kentucky Cat Colony

This manuscript describes an animal cruelty investigation in which several cats from a feral colony were suspected of having been poisoned. Three of the cats were submitted for complete postmortem examination by a qualified veterinary pathologist, and appropriate toxicologic analyses were selected and interpreted by a qualified veterinary toxicologist. Diagnosis in poisoning cases requires communication and collaboration between the pathologists and the toxicologist. A truly definitive diagnosis is not always possible in poisoning cases, particularly in a forensic investigation – a court of law requires a higher standard to establish a cause of death than do routine diagnostic cases. This case series illustrates the importance of a thorough diagnostic workup in forensic animal death investigations

Engaging Families in Supporting their Students

Parents and families are a key factor in college student success. As such, it is critical that institutions develop positive relationships with the families of students, particularly during new student orientation programs. Appreciative Advising has been used as a solid model for advisors and mentors to work with students on nurturing meaningful partnerships, generating co-constructed paths to success, and providing individualized sets of tools and timelines for personal development. Appreciative Advising is an effective, proven framework for enhancing student success which can be applied to working with parents durign new student orientation. The six-phase model can be taught to parents as a way to empower them to assist their student in achieving their educational and personal goals