17179 research outputs found
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Oral history interview: Joseph Colarusso
No full textEdited and unedited transcript files (.pdf) and edited and unedited video files available with closed captioning.Oral history interview with Barbara and Joseph Colarusso, Jr. about Joseph Colarusso. They share memories of Joseph's life and service
Mapping Spaceflight Microbial Corrosion with SEM, Robust Protocols Applied to CRS-21 and CRS-29
No full textEssential to life aboard the International Space Station (ISS), the Environmental Control and Life Support System (ECLSS) recycles every drop of sweat, breath, and urine into the crew’s sole supply of drinking water. The closed loop routes wastewater through vacuum distillation, multifiltration, catalytic oxidation, and a final biocide dose, using iodine on the United States Orbital Segment (USOS) and silver fluoride (AgF) on the Russian segment. Although these treatments destroy most microorganisms, a small fraction of bacteria from astronauts’ skin, respiratory, and urogenital microbiomes survives processing, enters distribution lines, attaches to stainless steel, and forms biofilms that tolerate residual disinfectants. These biofilms jeopardize crew health, choke plumbing, and drive microbial induced corrosion (MIC), an electrochemical attack that strips the chromium oxide passivation layer and drills pits into steel. On Earth the same process exacts a multibillion-dollar toll on pipelines, hulls, cooling towers, power plants, and implants. The USOS currently relies on iodine as its disinfectant biocide, but iodine imparts an unpleasant taste, requires post-treatment filtration, and can disturb thyroid function, so there is an interest towards adopting AgF instead, which remains palatable in situ and provides broad antimicrobial activity without extra processing. Determining whether AgF can reliably control mixed-species biofilms and limit corrosion, while continuing to study bacterial persistence, biofilm dynamics, and corrosion under microgravity, will guide future upgrades on the USOS and ensure system integrity and water quality during long-duration missions.
Our investigations, comprising the longest controlled flight experiment to date on microbial corrosion, simultaneously tested polymicrobial biofilm growth, MIC progression, and the viability of AgF as a disinfectant on stainless steel materials. Stainless steel coupons were immersed in a polymicrobial mixed culture of Pseudomonas aeruginosa PAO1 and Escherichia coli F11 in an artificial urine medium (AUM) that mimics WRS fluid, then flown on SpaceX CRS-21 for three time points (16 d, 24 d, 117 d) and on CRS-29 for (4 d, 14 d, 117 d), with ground controls started within a 16 h window to match flight timelines. Half of the samples contained AgF, allowing direct comparison with untreated counterparts. A precise tool for measuring MIC is urgently needed, and recent advances in machine learning (ML) provide an opportunity to convert raw scanning electron microscopy (SEM) images into numeric descriptors, so we built an AI-ready corpus that follows best-practice principles of exhaustive coverage, rich metadata, transparent provenance, and standard annotations. High-resolution SEM captured more than a hundred thousand images, each tagged with magnification, mission day, disinfectant status, and alloy batch, giving ML models the context required to segment pits, count their frequency, and measure material loss. Images from CRS-21 show pronounced pitting and surface roughening, likely driven by a reactive steel batch, whereas CRS-29 coupons from a different batch display minimal metal loss yet robust biofilm persistence even with AgF; these visual patterns remain qualitative until algorithms assign numeric values. While corrosion was not as apparent on CRS-29, SEM confirmed bacteria on every inoculated coupon regardless of disinfectant, indicating that biofilm growth is a dominant survival strategy in microgravity. The divergent outcomes between steel batches underscore how material composition and environmental factors govern MIC. This large-scale, robust dataset lays the groundwork for developing a novel pipeline that will convert SEM images of spaceflight MIC into quantitative metrics, enabling us to determine whether microgravity accelerates corrosion relative to ground controls, map damage progression across time points, and evaluate the protective value of AgF, yielding automated insights that guide material and disinfectant choices for future long-duration missions.Biolog
Vehicle Routing and Resource Allocation in Nonprofit Settings with Uncertain Volunteer Driver Availability
No full textThe purpose of this research is to develop a robust operational framework tailored to nonprofit and community-based organizations, supporting their unique distribution and logistical needs. The challenges of last-mile delivery intensify for these organizations, especially given their limited resources. "Meals on Wheels Central Texas," a nonprofit focused on serving elderly populations, exemplifies this challenge, as it relies on three types of drivers: volunteers, paid drivers, and staff. The organization prioritizes volunteer drivers to minimize costs, but the unpredictable nature of volunteer availability complicates the delivery process. When volunteers are unable to fulfill their routes, a rapid reassignment to other available drivers becomes essential to ensure continuous service. Our research addresses the vehicle routing problem with time windows (VRPTW), specifically adapted for nonprofits, by creating two specific optimization models that accommodate different driver types and emphasize cost-effective route allocation. The first deterministic model seeks to maximize volunteer participation with an emphasis on assigning routes to volunteers to optimize cost savings and considers paid or staff drivers as necessary to maintain coverage. To complement the model, we have developed a hybrid Tabu-Large Neighborhood Search metaheuristic solution method to tackle large scale problems. In our second model we have established a stochastic model considering volunteer driver’s unavailability and proposed a contingency framework to allocate routes to paid or staff drivers. The comparison between deterministic and stochastic models represents valuable insights, aiding non-profit organizations to understand the trade-off between cost and efficiency highlighting the impact of uncertainty on organizational functionality. By implementing this VRPTW framework, nonprofits can achieve a sustainable balance between cost management and responsiveness, ultimately strengthening their capacity to serve communities effectively amidst resource constraintsEngineerin
Intermittent Fasting and Culturally Conscious Dietary Guidance in Hispanic Immigrants [poster]
No full textNo abstract prepared.Nursin
SEAHIVE: A Novel Solution for Mitigating Local Scour at Bridge Piers
No full textThis research investigates the effectiveness of SEAHIVE elements as a novel countermeasure for mitigating local scour around bridge piers. Bridge scour is a notable concern in maintaining the safety and longevity of aging infrastructure, particularly as extreme weather events associated with climate change become more frequent. Traditional scour mitigation techniques, such as riprap and gabion mattresses, often rely on post-scour formation, which does not address potential damage before it occurs. This thesis explores SEAHIVE elements as an innovative, proactive solution to reduce scour formation, focusing on their use as standalone protection systems around bridge piers or integrated as standalone monopiles. Through hydraulic flume experiments, SEAHIVE elements were tested against conventional circular monopiles to assess their impact on scour reduction. The research examines the interaction between SEAHIVE structures and fluid flow, assessing their ability to dissipate hydraulic energy and reduce the magnitude of erosion around bridge foundations. Results from these experiments, conducted in a hydraulic flume under consistent experimental conditions, show that a standalone SEAHIVE element reduces scour depth by 7% compared to a conventional circular monopile. Furthermore, when SEAHIVE elements are grouped laterally and placed at a set distance of 3 pier diameters from the front of a monopile, scour depth reduction is enhanced to 70.2%. These results suggest that SEAHIVE elements, both as standalone and in lateral configurations, offer a highly effective and adaptable solution for mitigating scour around bridge piers, with potential applications for both new and existing bridges, particularly in flood-prone areas. This research contributes to the growing body of knowledge on scour countermeasures, offering valuable insights into the application of bio-inspired designs for improving the resilience of critical infrastructure.Engineerin
Gaze prediction as a function of eye movement type and individual differences
No full textSupplemental Material: Article Supplemental Material ETRA2025.zipEye movement prediction is a promising area of research with the potential to improve the performance and user experience of systems based on eye-tracking technology. In this study, we analyze individual differences in gaze prediction performance. We use three fundamentally different models: the lightweight Long Short-Term Memory Network (LSTM), the transformer-based network for multivariate time-series representation learning (TST), and the Oculomotor Plant Mathematical Model wrapped in the Kalman Filter framework (OPKF). Each solution was assessed on different eye movement types. We show an important subject-to-subject variation for all models and eye movement types. We found that signal noise during fixation is associated with poorer gaze prediction. High saccade velocity is associated with poorer gaze prediction. These individual differences are important, and it is proposed that future research should report statistics related to inter-subject variation. We also propose that future models should be designed to reduce subject-to-subject variation.Computer Scienc
Oral history interview: Winifred Gene Williams
No full textTranscript file (.pdf) and closed captioning available.Video interview with Gene William's family, who shares and reflects on the life of Colonel Winifred Gene Williams
Short-Term Associations Between Alcohol and Suicidal Thoughts: An Ecological Momentary Assessment Study
No full textSuicide is a pressing public health concern. Suicide risk factors have been examined, though suicide rates are not declining despite identifying these risk factors. One such established risk factor for suicide is alcohol use. Yet, information related to the short-term associations and temporal dynamics of suicidal ideation and alcohol use is limited. This study aimed to examine the short-term associations between alcohol use and suicidal thoughts within the context of internalizing symptoms (e.g., depression, anxiety), as well as coping and enhancement drinking motives for alcohol using ecological momentary assessments (EMA). Participants included 180 undergraduate college students 18 to 59 years (M = 21.53; 63.89% White, 78.89% cisgender women, 45.56% heterosexual). Participants completed an online consent form and a self-report questionnaire before enrolling into an EMA app. Findings demonstrated a significant association between alcohol use and suicidal thought presence and intensity at the between-person level but not at the within-person level. Depression and anxiety moderated the relationship between alcohol use and suicidal thought intensity both at the within-person level, but only anxiety at the between-person level. Lastly, enhancements motives were negatively related to suicidal thought intensity, yet coping motives were unrelated. In total, these findings implicate the role of greater than average levels of alcohol use on elevated suicidal thought intensity. This work also indicates important clinical implications, such that anxiety symptoms may be particularly important to target. Similarly, expanding on the benefits of enhancement motives (e.g., social connectedness) may be important in addressing suicidal ideation in college students. Future work should continue this work in a diverse sample that comprises of greater suicidal thought presence and alcohol use.Psycholog
A Comprehensive Review of Droughts in Texas and Their Implications on Water Policy and Future Management Strategies
No full textProlonged and extreme droughts have plagued the Texas region for centuries. Texas has faced hydrological, agricultural, ecological, and economic impacts from three major drought events: the 1950s, the 2010s, and the current drought, which has caused significant damage across all sectors. Climate models indicate that droughts will continue to be a recurring feature and will intensify due to population surges, climate change, and increased water demands. Statistical evidence suggests that our water supplies are being diminished due to the increased frequency of droughts. Major river basins in Texas, such as the Brazos, Colorado, Guadalupe, Nueces, Rio Grande, and San Antonio, experienced low water levels and extreme drying rates in certain segments during drought periods. Depleted water sources in the river basins are impacting ecologically critical species that are vital to the functionality of these water systems. Due to recurring drought events, the populations of many endangered and native species are declining at an alarming rate, and some are even facing extinction. The establishment of historical water policy and regulation was integral in providing the foundational framework for managing surface water in Texas. The ongoing threat of drought, coupled with the growing population, is causing an extreme water scarcity issue in Texas. This paper synthesizes relevant literature that explores the recurring effects of droughts and their impact on the effectiveness of Texas water policy. A primary goal of this paper is to discuss how various management strategies can be integrated to conserve our water supply, enabling us to become more resilient to future droughts in Texas.Geography and Environmental Studie
Navigating Legislation: Applying an Interpretive Phenomenology to Examine Texas Community College INRW Practitioners' Experiences of Policy Implementation
No full textLegislation impacting developmental education (DE) courses has become widespread across the U.S. in response to criticism and misinformation regarding the effectiveness of these courses in helping students earn a college degree, despite evidence highlighting DE's crucial role in supporting the academic needs of postsecondary students. In 2018, Texas legislation, House Bill 2223 (HB 2223), restructured DE literacy courses into a corequisite model. DE practitioners across the state were tasked with pairing an accelerated, integrated reading and writing (INRW) course with another college course for students to take concurrently. This combination of historical DE course models was considered experimental and not supported by empirical evidence. With 61% of students entering Texas community colleges considered “not college ready”, understanding how this legislation was actualized is essential to increasing degree completion and students' success in college. Previous studies have examined instructional practices and qualitative approaches examining DE practitioners' perspectives with similar state legislation. Yet, there remains a notable absence of in-depth analysis regarding the lived experiences of Texas community college INRW practitioners who implemented legislation impacting DE courses. This interpretive phenomenological study explored five Texas community college INRW practitioners' experiences before and during the scaled implementation of HB 2223 from 2018 to 2022. Eight thematic findings were constructed from understanding how they navigated HB 2223. Implications and recommendations for practitioners, policymakers, and future research are offered from these findings. By documenting the lived experiences of INRW practitioners, this study provided invaluable insights into the realities of postsecondary legislation implementation.Curriculum and Instructio