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We study the asymptotic geometry of a family of conformally planar minimal surfaces with polynomial growth in the Sp(4,R)-symmetric space. We describe a homeomorphism between the “Hitchin component” of wild Sp(4,R)- Higgs bundles over CP1 with a single pole at infinity and a component of maximal surfaces with light-like polygonal boundary in H2,2. Moreover, we identify those surfaces with convex embeddings into the Grassmannian of symplectic planes of R4. We show, in addition, that our planar maximal surfaces are the local limits of equivariant maximal surfaces in H2,2 associated to Sp(4,R)-Hitchin representations along rays of holomorphic quartic differentials. 

We define and prove the existence of unique solutions of an asymptotic Plateau problem for spacelike maximal surfaces in the pseudo-hyperbolic space of signature (2, n): the boundary data is given by loops on the boundary at infinity of the pseudo-hyperbolic space which are limits of positive curves. We also discuss a compact Plateau problem. The required compactness arguments rely on an analysis of the pseudo-holomorphic curves defined by the Gauß lifts of the maximal surfaces. 

In this research-based paper, we explore the relationships among Rice University STEM students’ high school preparation, psychological characteristics, and career aspirations. Although greater high school preparation in STEM coursework predicts higher STEM retention and performance in college [1], objective academic preparation and college performance do not fully explain STEM retention decisions, and the students who leave STEM are often not the lowest performing students [2]. Certain psychosocial experiences may also influence students’ STEM decisions. We explored the predictive validity of 1) a STEM diagnostic exam as an objective measure of high school science and math preparation and 2) self-efficacy as a psychological measure on long-term (three years later) STEM career aspirations and STEM identity of underprepared Rice STEM students. University administrators use diagnostic exam scores (along with other evidence of high school underpreparation) to identify students who might benefit from additional support. Using linear regression to explore the link between diagnostic exam scores and self-efficacy, exam scores predicted self-efficacy a semester after students’ first semester in college; exam scores were also marginally correlated with self-efficacy three years later. Early STEM career aspirations predicted later career aspirations, accounting for 21.3% of the variance of career outcome expectations three years later (β=.462, p=.006). Scores on the math diagnostic exam accounted for an additional 10.1% of the variance in students’ three-year STEM career aspirations (p=.041). Self-efficacy after students’ first semester did not predict future STEM aspirations. Early STEM identity explained 28.8% of the variance in three-year STEM identity (p=.001). Math diagnostic exam scores accounted for only marginal incremental variance after STEM identity, and self-efficacy after students’ first semester did not predict three-year STEM aspirations. Overall, we found that the diagnostic exam provided incremental predictive validity in STEM career aspirations after students’ sixth semester of college, indicating that early STEM preparation has long-lasting ramifications for students’ STEM career intentions. Our next steps include examining whether students’ diagnostic exam scores predict STEM graduation rates and final GPAs for science and math versus engineering majors. 

Sulfur oxidation state is used to tune organic room temperature phosphorescence (RTP) of symmetric sulfur-bridged carbazole dimers. The sulfide-bridged compound exhibits a factor of 3 enhancement of the phosphorescence efficiency, compared to the sulfoxide and sulfone-bridged analogs, despite sulfone bridges being commonly used in RTP materials. In order to investigate the origin of this enhancement, temperature dependent spectroscopy measurements and theoretical calculations are used. The RTP lifetimes are similar due to similar crystal packing modes. Computational studies reveal that the lone pairs on the sulfur atom have a profound impact on enhancing intersystem crossing rate through orbital mixing and screening, which we hypothesize is the dominant factor responsible for increasing the phosphorescence efficiency. The ability to tune the electronic state without altering crystal packing modes allows the isolation of these effects. This work provides a new perspective on the design principles of organic phosphorescent materials, going beyond the rules established for conjugated ketone/sulfone-based organic molecules. 

STEM graduation rates, cumulative GPAs, and final GPA distributions of years 2016 to 2019 graduates were evaluated for students who participated in Rice University’s STEM intervention (the Rice Emerging Scholars Program, or RESP, which is partly funded through an NSF SSTEM grant), which begins with a pre-freshman STEM summer bridge program. RESP participants (n=89) and a comparison category of students (n=81) were identified as being underprepared for STEM coursework. Outcomes from the rest of the graduating classes were also assessed (i.e., non-comparison, non-RESP students). Incoming high school AP and IB credits were a moderate predictor of cumulative graduation GPA. After controlling for test credits, student status predicted cumulative graduation GPA, with higher GPAs in the noncomparison, non-RESP condition. Seventy-two RESP students graduated with a STEM major (81% STEM retention) compared with 62% of comparison students and 87% of non-comparison, non-RESP students. A chi-square test found a significant difference in favor of higher STEM retention among RESP students than the comparison students. Of RESP STEM graduates, 94% graduated with at least a B- GPA, compared with 86% of the comparison students, and 97% of the non-comparison, non-RESP students. A chi-square test approached significance in favor of more B- and above GPAs among RESP students than the comparison students. Overall, we found that high school preparation predicted STEM students’ graduation GPAs. Further, although RESP participation did not predict the cumulative GPAs of STEM majors, the program may: 1) improve STEM degree persistence and 2) ensure that more of the program’s STEM graduates achieve at least a B- cumulative graduation GPA. The number of RESP and comparison students is relatively small, yet these findings nevertheless offer preliminary evidence that the intervention may be effective at improving STEM outcomes for students who would otherwise struggle the most with their coursework. As more students graduate from the university, we will be able to make stronger conclusions about the effectiveness of RESP in improving outcomes of underprepared STEM students. 

To combat math underperformance among incoming STEM majors, Rice University designed a summer bridge program with National Science Foundation (NSF) S-STEM funding that included an intensive calculus course. Students invited to participate in the program were identified as being underprepared for STEM classes based on their standardized test scores, high school STEM coursework, and socioeconomic status. One of the program’s goals is to improve students’ preparation for the advanced math courses required for all STEM majors at Rice. The bridge program is designed to teach the material that has historically been most challenging for underprepared students, meaning the math content covered primarily second-semester calculus topics. We explored the impact of bridge program participation on math performance in first and second-semester math. First, we examined group differences in math preparation. Though program administrators attempt to create equivalent bridge and comparison groups, the bridge program is optional, meaning group assignment is not completely random. Bridge students were less prepared than comparison students on number of high school calculus AP (or equivalent) credits received. We analyzed group differences in final class grades from 2012-2017 among the comparison group, the bridge group, and the rest of the class (i.e. non-comparison and nonbridge), standardizing grades using Z-scores. Planned contrasts found that bridge students performed slightly better than, but not significantly different from, comparison students in first semester math. Conversely, planned contrasts found that the bridge group significantly outperformed the comparison group in second-semester math. These results suggest that bridge program exposure to calculus may improve performance relative to a comparison group, which is especially noteworthy because bridge students are the least math-prepared STEM students entering the university. Future research will analyze outcomes in more advanced math classes. We will use these findings to refine the bridge program’s approach to teaching students how to succeed at collegiate-level math classes and, ultimately, as STEM majors at Rice. 

In this research-based paper, we discuss the development of a measure of Rice University students’ STEM study strategies and then explore the measure’s correlation with several important psychological outcomes in a sample of underprepared first-year STEM students (n=94). STEM attrition remains a pressing concern nationally, particularly for students who took less rigorous STEM courses in high school, a population that disproportionally comprises underrepresented minorities. The authors developed an 11-item measure of STEM-specific study strategies, termed the STEM Study Strategies Questionnaire. We explored STEM-specific identity, self-efficacy, and career aspirations, as well as perceived utility of attaining a STEM degree, using a model based on Eccles and Wigfield’s (2002) expectancy-value framework of achievement. An exploratory factor analysis found a four-factor solution to the newly developed scale: Group Work in STEM, Active STEM Learning, Interactions with STEM Professors, and STEM Exam Familiarity. The authors found significant moderate to strong correlations among all psychological variables, as well as with the Group Work and STEM Exam Familiarity factors. Next steps for this research are to develop further measure items to capture each of the four factors and to conduct confirmatory analyses on different samples of STEM students, both those who are relatively underprepared and appropriately prepared for college STEM coursework.