Gendered STEM Beliefs and Major Choice

Beliefs and expectations about who can and should pursue STEM careers contribute to a student’s sense of STEM identity and may help to explain the gender gap in pursuing STEM in higher education. The formation of these beliefs is a long and complex process, starting very early on in an individual’s life. We analyze how gendered STEM beliefs of students, parents, and teachers in ninth grade affect a female student’s probability of majoring in STEM in college. We add to an analysis done by Sansone (2019) in an appendix of his paper by using actual majors instead of intended majors. We slightly alter Sansone’s model and find a positive effect of beliefs in female superiority in science, both at the student and teacher level

Does online search improve the match quality of new hires?

This paper studies the effects of the high-speed internet expansion on the match quality of new hires. They combine data on internet availability at the local level with German individual register and vacancy data. Results show that internet availability has no major impact on the stability of new matches and their wages. The authors confirm these findings using vacancy data, by explicitly comparing match outcomes of online and non-online recruits. Further results show that online recruiting not only raises the number of applicants and the share of unsuitable candidates per vacancy, but also induces employers to post more vacancies

Dynamic association between perfusion and white matter integrity across time since injury in Veterans with history of TBI.

ObjectiveCerebral blood flow (CBF) plays a critical role in the maintenance of neuronal integrity, and CBF alterations have been linked to deleterious white matter changes. Although both CBF and white matter microstructural alterations have been observed within the context of traumatic brain injury (TBI), the degree to which these pathological changes relate to one another and whether this association is altered by time since injury have not been examined. The current study therefore sought to clarify associations between resting CBF and white matter microstructure post-TBI.Methods37 veterans with history of mild or moderate TBI (mmTBI) underwent neuroimaging and completed health and psychiatric symptom questionnaires. Resting CBF was measured with multiphase pseudocontinuous arterial spin labeling (MPPCASL), and white matter microstructural integrity was measured with diffusion tensor imaging (DTI). The cingulate cortex and cingulum bundle were selected as a priori regions of interest for the ASL and DTI data, respectively, given the known vulnerability of these regions to TBI.ResultsRegression analyses controlling for age, sex, and posttraumatic stress disorder (PTSD) symptoms revealed a significant time since injury × resting CBF interaction for the left cingulum (p < 0.005). Decreased CBF was significantly associated with reduced cingulum fractional anisotropy (FA) in the chronic phase; however, no such association was observed for participants with less remote TBI.ConclusionsOur results showed that reduced CBF was associated with poorer white matter integrity in those who were further removed from their brain injury. Findings provide preliminary evidence of a possible dynamic association between CBF and white matter microstructure that warrants additional consideration within the context of the negative long-term clinical outcomes frequently observed in those with history of TBI. Additional cross-disciplinary studies integrating multiple imaging modalities (e.g., DTI, ASL) and refined neuropsychiatric assessment are needed to better understand the nature, temporal course, and dynamic association between brain changes and clinical outcomes post-injury

Sex Differences in the Relationship Between Baroreflex Effectiveness Index and Spontaneous Cardiac Baroreflex Sensitivity

Baroreflex effectiveness index (BEI) is a relatively new measure used to assess cardiac baroreflex function. It is unclear whether BEI provides independent or complementary information compared to traditional spontaneous cardiac baroreflex sensitivity (BRS) measures. PURPOSE: The purpose of this project was to begin to explore the relationship between BEI and BRS in young adults and to investigate the impact of sex on these potential relationships. We hypothesized that there would be a positive correlation between BEI and BRS in both males and females. METHODS: We studied 45 young healthy adults, 17 males (24 ± 4 years) and 28 females (23 ± 4 years). Heart rate (ECG) and beat-to-beat arterial blood pressure (finger photoplethysmography) were continuously recorded during a five-minute resting baseline. Spontaneous cardiac BRS was measured using the Sequence Method, by identifying the gain of the relationship between systolic blood pressure and RRI from sequence(s) of three or more consecutive heartbeats in which systolic blood pressure and RRI change in the same direction. BEI was quantified as the ratio of the number of baroreflex-driven ramps relative to all systolic blood pressure ramps. RESULTS: BEI (Male: 0.65 ± 0.14, Female: 0.61 ± 0.13; mean ± SD, p=0.27) and BRS (Male: 21.3 ± 8.4, Female: 27.27 ± 12.6, p=0.09) between groups was not different. There was no significant relationship between BEI and BRS among all participants (r= 0.13, p= 0.36). However, sex-specific analysis data revealed a positive correlation in our male group (r= 0.57, p=0.01), and no relationship in our female group (r= 0.03, p=0.84). CONCLUSION: These preliminary data suggest that the relationship between BEI and BRS may be sex-dependent

Monolith-based68Ga processing: A new strategy for purification to facilitate direct radiolabelling methods

The post-processing of68Ga generator eluate by means of a novel high capacity cation-exchange silica monolith column has been validated in this work. Quantitative release of a purified68Ga solution in high concentration can be achieved using weak acidic solutions which can be directly used for chelator or conjugate labelling in an injectable form with improved radiochemical characteristics. The system has the potential to be incorporated in a flow based microfluidic system for dose-on-demand radiotracer synthesis

Exploring the Relationships between South Texas Northern Bobwhite Populations and Cecal Worms via System Dynamics

Community ecology historically focused on plants and free-living organisms; however, problems such as defining habitat boundaries and obtaining adequate sample sizes arise when evaluating such communities. The unique nature of host-helminth systems allows parasite community ecologists to avoid these problems when testing ecological hypotheses. Unlike free-living communities that have artificially constructed boundaries, parasite communities have well-defined unambiguous boundaries within host individuals. Due to the inherently complex and dynamic nature of ecological systems, traditional experimental methods often require expensive, long-term trials beyond investigators’ time and resource budgets. Conversely, a system dynamics approach facilitates learning about such systems via simulation of ecosystem processes integrated with historical data (both quantitative and qualitative). Relatively few studies focus on parasites in South Texas, USA, although research on avian host-parasite systems has shown that parasites can potentially regulate host populations. The northern bobwhite (Colinus virginianus; hereafter, bobwhite) is a game species of ecological, economic, cultural, and recreational importance in Texas that has been experiencing a long-term, widespread decline. To holistically examine the bobwhite-helminth system in South Texas, we created a system dynamics model capturing the feedback relationships between a South Texas bobwhite population, a grasshopper (family Acrididae) population, and the corresponding cecal worm (Aulonocephalus pennula) populations on a hypothetical 1,000-acre ranch in South Texas. The model structure, constructed in Vensim® PLE 7.2 software (Ventana Systems, Inc.), integrates the hypothesized biotic and abiotic drivers (precipitation, parasite load, insect abundance, and quail density) unique to the host-helminth system over 7 years (2012–2019). Our specific objectives were to 1) develop a working baseline model to replicate the synergistic population dynamics among bobwhite, grasshopper, and cecal worm populations and then 2) test hypotheses about each population’s boom-and-bust cycles resulting from environmental stressors (e.g., drought). Applications of the model can provide landowners and natural resource managers with a better understanding of the complex dynamics occurring among bobwhite, grasshopper, and cecal worm populations in South Texas

Assessing the ability of human endothelial cells derived from induced‐pluripotent stem cells to form functional microvasculature in vivo

Forming functional blood vessel networks is a major clinical challenge in the fields of tissue engineering and therapeutic angiogenesis. Cell‐based strategies to promote neovascularization have been widely explored, but cell sourcing remains a significant limitation. Induced‐pluripotent stem cell‐derived endothelial cells (iPSC‐ECs) are a promising, potentially autologous, alternative cell source. However, it is unclear whether iPSC‐ECs form the same robust microvasculature in vivo documented for other EC sources. In this study, we utilized a well‐established in vivo model, in which ECs (iPSC‐EC or human umbilical vein endothelial cells [HUVEC]) were coinjected with normal human lung fibroblasts (NHLFs) and a fibrin matrix into the dorsal flank of severe combined immunodeficiency mice to assess their ability to form functional microvasculature. Qualitatively, iPSC‐ECs were capable of vessel formation and perfusion and demonstrated similar vessel morphologies to HUVECs. However, quantitatively, iPSC‐ECs exhibited a two‐fold reduction in vessel density and a three‐fold reduction in the number of perfused vessels compared with HUVECs. Further analysis revealed the presence of collagen‐IV and α‐smooth muscle actin were significantly lower around iPSC‐EC/NHLF vasculature than in HUVEC/NHLF implants, suggesting reduced vessel maturity. Collectively, these results demonstrate the need for increased iPSC‐EC maturation for clinical translation to be realized.Forming functional blood vessel networks is a major clinical challenge in the fields of tissue engineering and therapeutic angiogenesis. Cell‐based strategies to promote neovascularization have been widely explored, but cell sourcing remains a significant limitation.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146963/1/bit26860.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146963/2/bit26860_am.pd