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Heterogeneity, reinforcement learning, and chaos in population games
No full textInspired by the challenges at the intersection of Evolutionary Game Theory and Machine Learning, we investigate a class of discrete-time multiagent reinforcement learning (MARL) dynamics in population/nonatomic congestion games, where agents have diverse beliefs and learn at different rates. These congestion games, a well-studied class of potential games, are characterized by individual agents having negligible effects on system performance, strongly aligned incentives, and well-understood advantageous properties of Nash equilibria. Despite the presence of static Nash equilibria, we demonstrate that MARL dynamics with heterogeneous learning rates can deviate from these equilibria, exhibiting instability and even chaotic behavior and resulting in increased social costs. Remarkably, even within these chaotic regimes, we show that the time-averaged macroscopic behavior converges to exact Nash equilibria, thus linking the microscopic dynamic complexity with traditional equilibrium concepts. By employing dynamical systems techniques, we analyze the interaction between individual-level adaptation and population-level outcomes, paving the way for studying heterogeneous learning dynamics in discrete time across more complex game scenarios
Defects in insulin secretion are the primary driver of higher diabetes risk in Turner syndrome
No full textMentored poster presentation at the Indiana University Center for Diabetes & Metabolic Disease Annual Symposiu
Many Moving Parts: New Transplant Allocation Models Are Associated With Increased Organ Travel and Potential Climate Implications
No full textBackground: Organ allocation has recently changed to acuity circle (AC)-based policies. This study aimed to quantify changes in travel distance and potential environmental impacts of AC policies.
Methods: Data were obtained from the Scientific Registry of Transplant Recipients for each solid organ for an equidistant window before and after AC implementation. We calculated the distance between the donor and recipient hospital for each organ. We used an interrupted time series model to calculate excess travel distance after AC along with associated carbon emissions.
Results: We analyzed travel distance for 226 731 deceased donor organs. There was a significant increase in total excess distance traveled: 1.5 × 106 miles for lung, 3.1 × 106 for heart, 2.2 × 106 miles for liver, and 3.2 × 106 miles for kidney. This led to increased estimated carbon emissions associated with transport ranging from: 175.7 to 193.4 kg CO2e per lung, 291.7 to 312.5 kg CO2e per heart, 114.9 to 131.7 kg CO2e per liver, and 0.2 to 5.3 kg CO2e per kidney.
Conclusions: Our findings quantify an increase in total distance traveled and potential carbon emissions after AC implementation. Environmental impacts of allocation policies should be considered, especially with upcoming continuous distribution
Placental MRI texture features in prenatal exposure to opioids and tobacco
No full textOpioid use disorder during pregnancy significantly increases the likelihood of adverse developmental outcomes in the offspring. Texture analysis serves as a quantitative technique that could be vital in identifying microstructural variations in placentas that have been exposed to opioids and other substances. This is a prospective, multisite cross-sectional study that recruited pregnant women that were greater than 16 weeks of gestation. We manually segmented placenta tissue from half-Fourier single-shot turbo spin-echo (HASTE) sequence MR images. We then assessed placental surface area and texture features using a radiomics pipeline. Using linear models, we assessed the association of substance use on placental surface area and texture features, accounting for demographic characteristics. There were 33 pregnant women with opioid use and 29 controls. Based on regression analysis, opioid exposure was associated with alterations in two texture features while tobacco exposure was associated with alterations in five texture features prior to multiple comparison correction. These were no longer significant after correcting for multiple comparisons. Additionally, tobacco exposure was significantly associated with greater placenta surface area
Trauma-Related Stress and Resilience in a Multistate Sample of Methadone Treatment Staff
No full textBackground: The quality of methadone treatment for opioid use disorder varies across the U.S., affecting patient retention and overdose. Staff stress, trauma exposure, vicarious trauma (VT), burnout, and empowerment are important yet understudied factors that influence workforce well-being and performance.
Objectives: This study aimed to characterize trauma-related well-being among staff in a national sample of opioid treatment programs (OTPs) and to explore potential correlates of resilience.
Design: A cross-sectional survey was conducted from June to August 2024 with OTP staff from clinics participating in a parent national study.
Methods: The survey combined validated instruments and tailored questions to assess work experience, lifetime trauma exposure, trauma and stress-related symptoms, VT, burnout, and multiple dimensions of empowerment. Exploratory factor analysis was used to identify domains of staff well-being.
Results: The sample (N = 86) included medical staff, counselors, and non-medical/counseling staff from OTPs across 16 states. Thirteen percent of staff met preliminary criteria for posttraumatic stress disorder, 89.2% reported VT exposure at work, and 63.8% reported moderate to severe VT symptoms. Medical staff reported the highest VT and stress scores. Overall, 19.8% of staff met criteria for burnout, with counselors reporting the highest rates (30%). VT symptoms were positively correlated with burnout among counselors, medical, and other staff (r = 0.413-0.650, P < .05). Empowerment subscales were strongly correlated. Two distinct, uncorrelated domains of staff well-being emerged: VT resilience (low VT symptoms and burnout) and empowerment (high perceived control and influence), reflecting distinct aspects of trauma-related functioning. Despite high exposure to lifetime trauma and VT, staff demonstrated moderate resilience and moderate-to-high levels of empowerment.
Conclusion: Staff of OTPs experience high levels of trauma exposure and symptomatology, VT, and burnout, with notable differences by clinic role. Resilience and empowerment domains suggest opportunities to improve staff wellness
Utilization of Adipose-Derived Stem Cells in Cranial Nerve Regeneration: A Comprehensive Review
No full textLarge peripheral nerve injuries may require surgical reconnection. Cell-based therapies have also been investigated for nerve regeneration. Within the context of this modern treatment paradigm for peripheral nerve injuries, we investigated the role of adipose-derived stem cells (ADSCs) in the regeneration of cranial nerves. PubMed and Embase databases were used to search for primary studies reporting the use of ADSCs in the regeneration of cranial nerves. A total of 12 studies were included, all of which presented data on specific neural injury, therapy, and functional outcomes. Eight studies focused on the facial nerve (66.7%), two on the optic nerve (16.7%), one on the olfactory nerve (8.3%), and one on the hypoglossal nerve (8.3%). One study applied ADSCs to human cranial nerve injuries, while the remainder studied animal models. In these studies, ADSC groups had higher numbers of myelinated fibers, increased myelin thickness, and diameter of muscle fibers, as well as greater magnitude of compound muscle action potentials (CMAP) when compared to controls. In studies focused on optic nerve regeneration, significant improvements across visual tests were observed. ADSCs demonstrate potential utility in regard to their ability to facilitate functional recovery of cranial nerves in humans and animal models. As such, this therapy merits further investigation so that its true clinical applications can be determined
Kinematic Convex Combinations of Multiple Poses of a Bounded Planar Object Based on an Average-Distance Minimizing Motion Sweep
No full textConvex combination of points is a fundamental operation in computational geometry. By considering rigid-body displacements as points in the image spaces of planar quaternions, quaternions and dual quaternions, respectively, the notion of convexity in Euclidean three-space has been extended to kinematic convexity in (2),(3), and (3) in the context of computational kinematic geometry. This paper deals with computational kinematic geometry of bounded planar objects rather than that of infinitely large moving spaces. In this paper, we present a new formulation for kinematic convexity based on an average-distance minimizing motion sweep of a bounded planar object. The resulting 1-DOF motion sweep between two planar poses is represented as a convex combination in the configuration space defined by (,,) where (,) is associated with the location of the centroid of the planar object and =sin with being the angle of rotation. For three poses, a 2-DOF motion sweep is developed that not only minimizes the combined average squared distances but also attains a convex-combination representation so that existing algorithms for convex hull of points can be readily applied to the construction and analysis of kinematic convex hulls. This results in a new type of convex hull for planar kinematics such that its boundaries are defined by the average-distance minimizing sweeps of the bounded planar object
Analyzing Team Engagement and Participation Patterns Through Dashboard-Driven Behavioral Profiling in Autism Support Settings
No full textThis project involved developing interactive data visualizations and analyzing team participation metrics in autism support classrooms as part of an internship at HANDS in Autism® Interdisciplinary Training and Resource Center. The work focused on REDCap data entry, survey tracking, and Power BI dashboard development for the Team Participation and Observation Profile (TPOP). These dashboards enabled site-specific filtering and scoring analysis across key behavioral dimensions such as engagement, participation, and cultural competence. Findings revealed strengths in staff engagement and roles clarity, with areas of improvement noted in cultural responsiveness and inclusive practices. This project enhanced technical fluency in Power BI, strengthened skills in structured data collection and analysis, and supported data-informed planning for school teams. The intern’s contributions directly advanced the organization’s goal of using behavioral insights to improve team performance and educational outcomes for students with ASD
Evaluation of the Prenatal Care Referral Process at a Student-Run Women's Health Clinic
No full textBackground: Early entry into the medical system is critical for both maternal and fetal health, as it allows for the timely identification and management of pregnancy-related complications, chronic conditions, and modifiable risk factors1. Student-run free clinics (SRFCs) can serve as points of entry into healthcare for underserved populations by offering primary and preventive care services to individuals who face significant barriers. However, these clinics are often restricted in the scope of the services they can provide due to limited resources and infrequent clinic operations 2. As a result, SRFCs must rely on referrals to external institutions. Given the importance of initiating comprehensive prenatal care early in pregnancy, we sought to evaluate the efficacy and efficiency of our referral process for prenatal patients at our student-run clinic.
Methods: This was a retrospective chart review of pregnant patients seen by the Indiana University Women’s Health Coalition (WHC) between January 1, 2023 and March 31, 2025. Staffed by an Obstetrician Gynecologist, the WHC is the gynecologic and prenatal care division of the Indiana University Student Outreach Clinic a free, student-run clinic that serves the Indianapolis community. We reviewed the charts of patients presenting to the WHC who were confirmed to be pregnant, intended to continue their pregnancy, and had not yet established prenatal care elsewhere. Data were extracted from appointment scheduling logs, patient navigator spreadsheets, and electronic medical records at the WHC and the referral hospital. Demographic data were collected including patient age at presentation, home ZIP code, and primary language. Pregnancy-related data such as gestational age at presentation, gravidity and parity were also collected. Outcome variables collected include the date of the patient’s first WHC visit, total number of WHC visits, referral initiation dates, and the date of the first prenatal appointment at the referral hospital. The primary outcome was the proportion of patients referred from the WHC to initiate prenatal care who completed their first prenatal visit. The secondary outcome was the average time (in days) it took from date of the patient’s first appointment at the WHC to the date of their first attended prenatal appointment at the referral hospital. Descriptive statistics were used to determine both the primary and secondary outcomes, as well as to summarize the demographics of the sample. This study was deemed exempt by the institutional review board.
Results: A total of 13 patients met inclusion criteria. The average patient age at presentation was 28.5 years. English was the primary language for most patients (6 of 13), followed by Spanish (5 of 13). The average distance from the patients’ home ZIP code to the referral hospital was 7.9 miles. Most patients were primigravida (61.5%), presenting at an average estimated gestational age of 16 weeks + 4 days. Of the 13 patients included, 11 attended a prenatal visit at the referral hospital, yielding a referral success rate of 84.6%. The average interval between the patient’s initial visit at the WHC and the first attended prenatal appointment at the referral hospital was 21.2 days.
Conclusion: This review suggests that the referral process from the WHC to the partner hospital is effective and efficient, with most patients successfully connecting to prenatal care in a timely fashion. Although the process is efficient, there remains an opportunity for further optimization