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Creators/Authors contains: "Cameron, A"

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  1. Abstract Socioeconomic disparities in academic progress have persisted throughout the history of the United States, and growth mindset interventions—which shift beliefs about the malleability of intelligence—have shown promise in reducing these disparities. Both the study of such disparities and how to remedy them can benefit from taking the “long view” on adolescent development, following the tradition of John Schulenberg. To do so, this study focuses on the role of growth mindsets in short‐term academic progress during the transition to high school as a contributor to longer‐term educational attainment. Guided by the Mindset × Context perspective, we analyzed new follow‐up data to a one‐year nationally representative study of ninth graders (National Study of Learning Mindsets,n = 10,013; 50% female; 53% white; 63% from lower‐SES backgrounds). A conservative Bayesian analysis revealed that adolescents' growth mindset beliefs at the beginning of ninth grade predicted their enrollment in college 4 years later. These patterns were stronger for adolescents from lower‐SES backgrounds, and there was some evidence that the ninth‐grade math teacher's support for the growth mindset moderated student mindset effects. Thus, a time‐specific combination of student and teacher might alter long‐term trajectories by enabling adolescents to develop and use beliefs at a critical transition point that supports a cumulative pathway of course‐taking and achievement into college. Notably, growth mindset became less predictive of college enrollment after the onset of the COVID‐19 pandemic, which occurred in the second year of college and introduced structural barriers to college persistence. 
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  2. In this study, we investigate in situ etching of β-Ga2O3 in a metalorganic chemical vapor deposition system using tert-butyl chloride (TBCl). We report etching of both heteroepitaxial 2¯01-oriented and homoepitaxial (010)-oriented β-Ga2O3 films over a wide range of substrate temperatures, TBCl molar flows, and reactor pressures. We infer that the likely etchant is HCl (g), formed by the pyrolysis of TBCl in the hydrodynamic boundary layer above the substrate. The temperature dependence of the etch rate reveals two distinct regimes characterized by markedly different apparent activation energies. The extracted apparent activation energies suggest that at temperatures below ∼800 °C, the etch rate is likely limited by desorption of etch products. The relative etch rates of heteroepitaxial 2¯01 and homoepitaxial (010) β-Ga2O3 were observed to scale by the ratio of the surface energies, indicating an anisotropic etch. Relatively smooth post-etch surface morphology was achieved by tuning the etching parameters for (010) homoepitaxial films. 
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  3. Teherani, Ferechteh H; Rogers, David J (Ed.)
  4. ABSTRACT We conducted a GPU-accelerated reprocessing of $$\sim 87~{{\ \rm per\ cent}}$$ of the archival data from the High Time Resolution Universe South Low Latitude (HTRU-S LowLat) pulsar survey by implementing a pulsar search pipeline that was previously used to reprocess the Parkes Multibeam Pulsar Survey (PMPS). We coherently searched the full 72-min observations of the survey with an acceleration search range up to $$|50|\, \rm m\, s^{-2}$$, which is most sensitive to binary pulsars experiencing nearly constant acceleration during 72 min of their orbital period. Here we report the discovery of 71 pulsars, including six millisecond pulsars, of which five are in binary systems, and seven pulsars with very high dispersion measures (DM $$\gt 800 \, \rm pc \, cm^{-3}$$). These pulsar discoveries largely arose by folding candidates to a much lower spectral signal-to-noise ratio than in previous surveys and by exploiting the coherence of folding over the incoherent summing of the Fourier components to discover new pulsars as well as candidate classification techniques. We show that these pulsars could be fainter and on average more distant as compared with both the previously reported 100 HTRU-S LowLat pulsars and the background pulsar population in the survey region. We have assessed the effectiveness of our search method and the overall pulsar yield of the survey. We show that through this reprocessing we have achieved the expected survey goals, including the predicted number of pulsars in the survey region, and discuss the major causes why these pulsars were missed in previous processing of the survey. 
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  5. Asymmetric cell division (ACD) allows stem cells to generate differentiating progeny while simultaneously maintaining their own pluripotent state. ACD involves coupling mitotic spindle orientation with cortical polarity cues to direct unequal segregation of cell fate determinants. InDrosophilaneural stem cells (neuroblasts; NBs), spindles orient along an apical-basal polarity axis through a conserved complex of Partner of Inscuteable (Pins; human LGN) and Mushroom body defect (Mud; human NuMA). While many details of its function are well known, the molecular mechanics that drive assembly of the cortical Pins/Mud complex remain unclear, particularly with respect to the mutually exclusive Pins complex formed with the apical scaffold protein Inscuteable (Insc). Here we identify Hu li tai shao (Hts; human Adducin) as a direct Mud-binding protein, using an aldolase fold within its head domain (HtsHEAD) to bind a short Mud coiled-coil domain (MudCC) that is adjacent to the Pins-binding domain (MudPBD). Hts is expressed throughout the larval central brain and apically polarizes in mitotic NBs where it is required for Mud-dependent spindle orientation.In vitroanalyses reveal that Pins undergoes liquid-liquid phase separation with Mud, but not with Insc, suggesting a potential molecular basis for differential assembly mechanics between these two competing apical protein complexes. Furthermore, we find that Hts binds an intact Pins/Mud complex, reduces the concentration threshold for its phase separation, and alters the liquid-like property of the resulting phase separated droplets. Domain mapping and mutational analyses implicate critical roles for both multivalent interactions (via MudCColigomerization) and protein disorder (via an intrinsically disordered region in Hts; HtsIDR) in phase separation of the Hts/Mud/Pins complex. Our study identifies a new component of the spindle positioning machinery in NBs and suggests that phase separation of specific protein complexes might regulate ordered assembly within the apical domain to ensure proper signaling output. 
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  6. Group-based educational disparities are smaller in classrooms where teachers express a belief that students can improve their abilities. However, a scalable method for motivating teachers to adopt such growth mindset–supportive teaching practices has remained elusive. In part, this is because teachers often already face overwhelming demands on their time and attention and have reason to be skeptical of the professional development advice they receive from researchers and other experts. We designed an intervention that overcame these obstacles and successfully motivated high-school teachers to adopt specific practices that support students’ growth mindsets. The intervention used the values-alignment approach. This approach motivates behavioral change by framing a desired behavior as aligned with a core value—one that is an important criterion for status and admiration in the relevant social reference group. First, using qualitative interviews and a nationally representative survey of teachers, we identified a relevant core value: inspiring students’ enthusiastic engagement with learning. Next, we designed a ~45-min, self-administered, online intervention that persuaded teachers to view growth mindset–supportive practices as a way to foster such student engagement and thus live up to that value. We randomly assigned 155 teachers (5,393 students) to receive the intervention and 164 teachers (6,167 students) to receive a control module. The growth mindset–supportive teaching intervention successfully promoted teachers’ adoption of the suggested practices, overcoming major barriers to changing teachers’ classroom practices that other scalable approaches have failed to surmount. The intervention also substantially improved student achievement in socioeconomically disadvantaged classes, reducing inequality in educational outcomes. 
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  7. Abstract BackgroundSingle‐session interventions have the potential to address young people's mental health needs at scale, but their effects are heterogeneous. We tested whether themindset + supportive contexthypothesis could help explain when intervention effects persist or fade over time. The hypothesis posits that interventions are more effective in environments that support the intervention message. We tested this hypothesis using the synergistic mindsets intervention, a preventative treatment for stress‐related mental health symptoms that helps students appraise stress as a potential asset in the classroom (e.g., increasing oxygenated blood flow) rather than debilitating. In an introductory college course, we examined whether intervention‐consistent messages from instructors sustained changes in appraisals over time, as well as impacts on students' predisposition to try demanding academic tasks that could enhance learning. MethodsWe randomly assigned 1675 students in the course to receive the synergistic mindsets intervention (or a control activity) at the beginning of the semester, and subsequently, to receive intervention‐supportive messages from their instructor (or neutral messages) four times throughout the term. We collected weekly measures of students' appraisals of stress in the course and their predisposition to take on academic challenges. Trial‐registration: OSF.io; DOI: 10.17605/osf.io/fchyn. ResultsA conservative Bayesian analysis indicated that receiving both the intervention and supportive messages led to the greatest increases in positive stress appraisals (0.35SD; 1.00 posterior probability) and challenge‐seeking predisposition (2.33 percentage points; 0.94 posterior probability), averaged over the course of the semester. In addition, intervention effects grew larger throughout the semester when complemented by supportive instructor messages, whereas without these messages, intervention effects shrank somewhat over time. ConclusionsThis study shows, for the first time, that supportive cues in local contexts can be the difference in whether a single‐session intervention's effects fade over time or persist and even amplify. 
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  8. Introduction In Midwestern maize ( Zea-mays L.)-based systems, planting an over-wintering cover crop such as rye ( Secale cereale L.) following fall harvests of summer crops maintains continuous soil cover, offering numerous environmental advantages. However, while adoption of cover crops has increased over the past decade, on a landscape-scale it remains low. Identifying where agronomic research could be most impactful in increasing adoption is therefore a useful exercise. Decision analysis (DA) is a tool for clarifying decision trade-offs, quantifying risk, and identifying optimal decisions. Several fields regularly utilize DA frameworks including the military, industrial engineering, business strategy, and economics, but it is not yet widely applied in agriculture. Methods Here we apply DA to a maize-soybean [ Glycine max (L.) Merr.] rotation using publicly available weather, management, and economic data from central Iowa. Results In this region, planting a cover crop following maize (preceding soybean) poses less risk to the producer compared to planting following soybean, meaning it may be a more palatable entry point for producers. Furthermore, the risk of reduced maize yields when planting less than 14 days following rye termination substantially contributes to the overall risk cover crops pose to producers, but also has significant potential to be addressed through agronomic research. Discussion In addition to identifying research priorities, DA provided clarity to a complex problem, was performed using publicly available data, and by incorporating risk it better estimated true costs to the producer compared to using input costs alone. We believe DA is a valuable and underutilized tool in agronomy and could aid in increasing adoption of cover crops in the Midwest. 
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