Social and Behavioral Sciences Commons^™

The Interplay Between Loneliness, Cortisol, And Nk Cell Function: The Role Of Cortisol In Nk Cell Dysfunction, Abhinav Saurabh, Yvonne Baumer, Laurel G. Mendelsohn, Elizabeth M. Aquino Peterson, Dana Sadler, Shirley J. Lopez De Leon, Ayushi Dave, Andrew S. Baez, Lola R. Ortiz-Whittingham, Mario A. Pita, Manuel A. Cintron, Hannatu A. Tarfa, Sandy T. Reynolds, Shelby R. Hicks, Sonal Sharda, J. Eleanor Seo, Maria Lopez-Ocasio, Pradeep K. Dagur, Skyler A. Kuhn, Neelam R. Redekar, James F. Troendle, Ayanna L. Wells, Marie Marah, Katherine J. Tolentino, Michael J. Corley, Alika K. Maunakea, Lynnette K. Nieman, Marcus R. Andrews, Tiffany M. Powell-Wiley

Department of Biomedical and Translational Sciences Faculty Publications

Chronic psychosocial stressors contribute to cardiovascular disease (CVD) and related risk factors, particularly in under-resourced communities. Psychosocial stressors activate the hypothalamic-pituitary-adrenal (HPA) axis, leading to sustained cortisol action on immune cells. Natural killer (NK) cells are altered in distribution and function in cardio-metabolic diseases; however, pathways linking cortisol as a marker of chronic stress to NK cell dysfunction remain understudied. We recruited 186 African American women from the Step It Up Community-Engaged, Digital Health Physical Activity Intervention study and collected cortisol, NK cell measures, and psychosocial stress measures using validated questionnaires, including chronic stress and loneliness. Plasma cortisol levels were …

The Effects Of Abused Drugs On Ferroptosis Pathways: Potential Therapeutic Targets For Substance Use Disorders, Tamara Bouchard, Brooke Russell, Liam Liyang Guo, Tina Nguyen, Yan Cheng, Yan Y. Sanders, Ming-Lei Guo

Department of Biomedical and Translational Sciences Faculty Publications

Substance use disorders (SUDs) remain major public health concerns worldwide, particularly in developed countries. SUDs are characterized by persistent neuroinflammation and synaptic dysfunction in the brain. Despite decades of extensive investigation, the detailed mechanisms underlying SUDs remain elusive. Ferroptosis is a highly regulated cell death process deeply affected by iron metabolism, lipid peroxidation, reactive oxygen species (ROS) production, and antioxidant systems. It has been implicated in multiple neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, multiple sclerosis, and ischemic stroke. Recently, emerging evidence has highlighted the role of ferroptosis in drug-induced pathological changes. Various types of abused …

Yk-4-250, A Synthetic Telmisartan-Tempol Conjugate: Crystal Structure Of A Stabilized Free Radical Containing An Angiotensin At₁ Receptor Inhibitor, Simon Friedrich, Yali Kong, Faik N. Musayev, Milton L. Brown, B. Frank Gupton

Department of Biomedical and Translational Sciences Faculty Publications

We report the first crystal structure of the telmisartan-tempol conjugate 2,2,6,6-tetramethyl-1-(λ'-oxidaneyl)piperidin-4-yl 4'-[(1,7'-dimethyl-2'-propyl-1H,3'H-[2,5'-bibenzo[d]imidazol]-3'-yl)methyl]-[1,1'-biphenyl]-2-carboxylate free radical (YK-4-250, C₄₂H₄₆N₅O₃), a dual-function inhibitor designed to target both the angiotensin II type 1 receptor (AT₁R) and reactive oxygen species (ROS). Structural analysis reveals a unique crystal architecture in which the nitroxide radical is stabilized within a sterically protected environment while preserving the telmisartan pharmacophore essential for high-affinity receptor antagonism. YK-4-250 is a novel small-molecule conjugate of telmisartan and tempol that incorporates a catalytic stabilized nitroxide radical and was rationally designed to mitigate gastrointestinal acute radiation syndrome (GI-ARS).

Resilient Built Environment: An Overview On Design Strategies For Coastal Adaptation To Sea Level Rise, Farzaneh Soflaei, Gelareh Abdolzadeh, Navid Ziaee, Mohammad Amin Jafari, Faeghe Borhani

Civil & Environmental Engineering Faculty Publications

This paper delves into the escalating risks faced by urban coastal communities due to tidal and storm flooding, exacerbated by climate change-induced Sea Level Rise (SLR). Projections indicate a potential increase in sea levels by at least 3 feet by 2100, with historical data revealing an average annual rise of 1.2-1.7 mm since the 1900s. With over 300 million individuals inhabiting coastal areas, low-lying regions emerge as particularly vulnerable to the impacts of SLR. This accelerated rise amplifies the significant challenge of nuisance flooding, a local-scale issue aggravated by high tide and winds, leading to inundation, road closures, infrastructure deterioration, …

Physics-Based Multi-Hazard Fragility Modeling Of Low-Rise Wood-Frame Buildings Under Hurricane-Induced Wind And Surge, Mumtasirun Nahar, Abdullah M. Braik, Mohammad Syed, Maria Koliou, Petros Sideris

Civil & Environmental Engineering Faculty Publications

Coastal buildings are exposed to concurrent hurricane-induced wind and storm surge, yet their vulnerability is commonly assessed using separate single-hazard models that neglect hazard interaction. This study developed a physics-based finite element framework to evaluate the performance of a low-rise light wood-frame building under simultaneous wind and surge-wave loading. A detailed three-dimensional model was constructed using a sub-assembly strategy that explicitly represented framing members, sheathing systems, and critical connections. Structural response was evaluated across a hazard space defined by wind speed, still-water depth, and flow velocity, and component- and system-level fragility functions were derived using Monte Carlo simulation and generalized …

Failure Mechanism Of A Small Vertical Pier Under Post-Typhoon Wind-Wave Forcing, Kyu Tae Shim, Kyu Han Kim, Bumshick Shin, Hyun Dong Kim

Civil & Environmental Engineering Faculty Publications

This study investigated the failure process and major contributing factors of the north pier at Hongdo, located off the southwestern coast of Korea, which has experienced repeated damage and a history of repair and reinforcement. The 2016 damage event was selected for detailed analysis. Because direct wave observations were not available at the time of the damage, the offshore wind field was reconstructed using WRF, and the wave conditions were estimated using WAM and SWAN. The waves in front of the pier during the damage event were estimated to have been lower than the design wave adopted for the reinforcement …

Association Between Neighborhood Social Determinants Of Health And Stillbirth, Tetsuya Kawakita, Misa Hayasaka, Ann M. Harper, John Brush, George Saade

Department of Obstetrics & Gynecology Faculty Publications

OBJECTIVE:

To examine the association between neighborhood-level social determinants of health and stillbirth.

METHODS:

We performed a retrospective cohort study of deliveries that occurred at a gestational age of at least 20 weeks within a five-hospital system (2012-2022). Electronic health record data mapped to the Observational Medical Outcomes Partnership Common Data Model were geocoded using addresses at the time of delivery and linked to neighborhood health indices, which included the Area Deprivation Index (ADI), Maternal Vulnerability Index (MVI), and Social Vulnerability Index (SVI) at the Census tract level. Stillbirths were adjudicated by medical record review. Modified Poisson regression generated relative …

Mediating Effect Of Social Determinants Of Health Between Race And Phthalate Biomarkers In Pregnancy, Tetsuya Kawakita, Misa Hayasaka, Carole Barake, Trinity Soto, Jillian Fleming, Amir Lueth, Stevens Danielle, Alfred Abuhamad, Ann Pryzybylska, Elena Sinkovskaya, Kelly K. Ferguson, George Saade

Department of Obstetrics & Gynecology Faculty Publications

Introduction

Prenatal phthalate exposure is linked to adverse reproductive and developmental outcomes and is consistently higher among non‐Hispanic Black compared to non‐Hispanic White pregnant individuals, yet the factors responsible for these disparities are poorly characterized. We sought to quantify Black–White differences in repeated urinary concentrations of phthalate biomarkers during pregnancy and to estimate the extent to which neighborhood‐level social determinants of health (SDoH) mediate these disparities.

Methods

This secondary analysis used data from the Human Placenta Project Study, a prospective observational cohort study conducted at two academic institutions between 2016 and 2018. Eligible participants had singleton pregnancies, were recruited before …

Differential Impact Of Admission Type And Clinical Complexity On Diabetes Hospitalization Costs Among African American And Hispanic Patients In Southeastern Virginia, Ismail El Moudden, Asra Amidi, Reem Sharaf-Alddin, Michael C. Bittner, Qi Zhang

Department of Obstetrics & Gynecology Faculty Publications

Background

Diabetes mellitus (DM) imposes substantial healthcare costs with documented disparities among African Americans and Hispanic patients. To inform care delivery and resource allocation, this study identified hospitalization cost predictors among African American and Hispanic patients with diabetes in Southeastern Virginia.

Methods

We analyzed 6,011 hospital discharges from the Virginia Health Information database (2016-2020) for adults aged 18-85 with diabetes. Discharges were classified by Medicare Severity Diagnosis-Related Groups: DM with complications/comorbidities (DCC, n = 3,328), DM with major complications/comorbidities (DMCC, n = 1,518), and DM without major complications/comorbidities (DWO, n = 1,165). Because cost distributions were right-skewed (skewness 3.5-8.24), we …

Biomechanical Integrity Of The Female Pelvic Floor: A Comparison Of Military And Civilian Women, Vladimir Egorov, Peter Takacs, Vincent Lucente, Heather Van Raalte, Joy A. Greer, Noune Sarvazyan

Department of Obstetrics & Gynecology Faculty Publications

Introduction

The health of the pelvic floor depends on the integrity of its muscles, connective tissue, ligaments, and their innervation. The female pelvic floor may be more vulnerable to repetitive heavy loads in a military environment than the male pelvic floor because of anatomical and physiological differences. The study aim was to identify and explore possible differences in the female pelvic floor conditions between active military and civilian women with similar demographics.To identify and explore possible differences in the conditions of the female pelvic floor between active military women and civilian women with similar demographics.

Materials and Methods

Military active …

Hungarian Validation Of The Pelvic Floor Distress Inventory - 20 (Pfdi-20) Questionnaire And The Pelvic Floor Impact Questionnaire - 7 (Pfiq - 7), Barbara Kozma, Bence Kozma, Peter Takacs, Dávid Rátonyi, Nelli Farkas, Attila G. Sipos, Balint Farkas

Department of Obstetrics & Gynecology Faculty Publications

Introduction and Hypotheses

Pelvic floor disorders (PFDs) affect women's quality of life through physical, psychological, and social domains. The Pelvic Floor Distress Inventory-20 (PFDI-20) and the Pelvic Floor Impact Questionnaire-7 (PFIQ-7) are validated tools for assessing symptom severity and quality of life impact. The current study aim to investigate the reliability and validity of the Hungarian versions of these questionnaires in women with PFD symptoms.

Methods

This validation study was carried out at the University of Debrecen among women with clinically confirmed pelvic floor disorders. The PFDI-20 and PFIQ-7 questionnaires were translated into Hungarian using independent native English speaker in …

The Impact Of The 7th October War On Preterm Birth Rates And Neonatal Outcomes: A Retrospective Comparative Study From Northern Israel, Raghda Zidan Sweid, Adi Sharabi Nov, Hana Helfgot, Steven L. Warsof, Inbar Ben-Shachar

Department of Obstetrics & Gynecology Faculty Publications

PURPOSE: Maternal psychological stress is associated with adverse obstetric and neonatal outcomes, including preterm birth and low birthweight. Warfare represents a significant source of acute and chronic stress, yet its impact on pregnancy outcomes remains unclear. This study aimed to evaluate the association between a 6-month period of continuous wartime exposure following October 7, 2023, during the "Iron Swords" conflict and preterm birth, neonatal outcomes, and obstetric management.

METHODS: This retrospective cohort study included all deliveries at ZIV Medical Center during the 6-month conflict period, compared with a pre-war cohort from 2021 until October 6, 2023. The primary outcome was …

The American Anomaly: Feasibility Of Universal Healthcare, William Bernstein

Student Research and Publications

No abstract provided.

Guide D’Immersion Français/Francophone Au Connecticut, Isa Amaro Varas

Student Research and Publications

No abstract provided.

Non-Destructive Hhxrf Archaeometry For Grouping Individuals Via Trace Element Analysis Of Dental Remains, Griffon G. Binkowski

Graduate Studies Theses and Dissertations 2026

Handheld X-ray fluorescence (HHXRF) spectrometry has been validated as an accurate, non-destructive method for analyzing archaeological osseous materials. This study utilizes HHXRF to address key bioarchaeological questions, including population differentiation, individuation, and the interpretation of bioaccumulated trace elements versus diagenetic impacts. Using dental enamel from the Maya site of Altun Ha, Belize (n=20) and several Roman-Christian sites in the Dakhleh Oasis in Egypt (n=6), the occlusal surface of molar crowns was assayed in air using a Bruker Tracer III- equipped with a 12 mil Al, 1 mil Ti, 6 mil Cu filter. Semi-quantitative trace element ratios (Sr/Ca, Fe/Ca, and Zn/Ca) …

17Β Estradiol Protection Against Medium-Change Neurotoxicity In Organotypic Hippocampal Slice Cultures, Autumn B. Stage

University of Kentucky Master's Theses

Medium change neurotoxicity can disrupt glutamate homeostasis and promote excitotoxic neuronal injury through excessive NMDA receptor activation. 17β estradiol (E2) has demonstrated neuroprotective effects in models of neuronal injury and may regulate glutamatergic signaling through metabotropic glutamate receptors (mGluR2/3). This study investigated whether E2 protects against medium change associated neurotoxicity in organotypic hippocampal slice cultures whether responses differed by sex or hippocampal region. Hippocampal slices from postnatal day 8 male and female Sprague Dawley rats were maintained in culture and exposed to 1, 10, or 100 nM E2 for 24 hours following a five day recovery period. Propidium iodide (PI) …

The Ability To Resist The Expected Impairing Effects Of Alcohol In Heavy And Light Drinkers, Grace Tomaszewski

University of Kentucky Master's Theses

Alcohol tolerance is defined as a diminished response to the drug owing to repeated alcohol exposures. However, drinkers can compensate for alcohol impairment, particularly when they expect to be impaired in the situation. However, the ability to compensate might depend on the behavior impaired by alcohol and the general tolerance already acquired by the drinker. This study tested the degree to which expecting alcohol impairment would reduce alcohol’s impairing effect on reaction time (RT) and fine motor control in those with heavy and light drinking histories. Light drinkers (n=26) and heavy drinkers (n=28) received a 0.65 g/kg alcohol and performed …

Assessing Positive Digital Experiences: A Spanish Validation Of The Digital Flourishing Scale For Adolescents, Alfredo Zarco-Alpuente, Victor Ciudad Fernández, Jasmina Rosič, Sophie Janicke-Bowles, Tamara Escrivà-Martínez, Paula Samper-García

Communication Faculty Articles and Research

Background: Adolescents are immersed in digital communication, which can benefit or harm their well-being. Digital flourishing captures positive perceptions of this communication-connectedness, authentic self-presentation, positive social comparison, civil participation, and self-control-and how it contributes to well-being. In Spain there is still no validated instrument for adolescents. Method: We adapted and validated the Digital Flourishing Scale for Adolescents (DFSA) for Spanish adolescents. Study 1 involved a pilot survey (n = 13) and cognitive interviews (n = 10) to improve clarity and cultural relevance. Study 2 used a cross-sectional survey (n = 1,786) to examine the DFSA’s latent structure, measurement invariance by …

Participation, Danielle M. Pillet-Shore

Faculty Publications

What does it take to participate in direct, naturally occurring social interaction? Conversation analytic (CA) studies reveal that “participation”—who participates, when, and how—is dynamic and locally, multimodally achieved by the people involved. Particularly in social situations when people are concurrently accessible to one another’s naked senses (Goffman, 1964), co-participation is enabled and performed through embodied and vocal resources including talk, gaze, facial displays, body orientation/posture, proximity, and gestures (e.g., M. H. Goodwin, 1999; C. Goodwin & M. H. Goodwin, 2005; Pillet-Shore, 2010; Sidnell, 2009). Using a multimodal CA lens, this chapter illuminates how “participation” is achieved in real-time, naturally occurring …

A Narrative Review Of Bertolotti's Syndrome: Etiology, Classification, Diagnosis, And Treatment, Matyas Abel Tsegaye, Andrea Muffly

Rehabilitation Sciences Faculty Publications

Bertolotti's syndrome is a congenital condition characterized by chronic low back pain stemming from a lumbosacral transitional vertebra (LSTV). Because the condition is frequently overlooked, patients often face years of delayed diagnosis before the true source of their pain is identified. Furthermore, current information regarding the biological origins and clinical management of the condition remain scattered. To address this knowledge gap, this narrative review aims to provide a comprehensive overview of Bertolotti’s syndrome by consolidating these disparate sources and suggesting new connections. We synthesize the latest understanding of this condition, ranging from its genetic origins to modern clinical management. We …

We-Making Through Technology: Social Cohesion And Virtual Adaptation In Community Arts Organizations For Artists With Idd During Covid-19 Pandemic, Yumi Shirai, Michelle Boulanger Thompson, Tamara Shetron

Rehabilitation Sciences Faculty Publications

COVID-19 public health restrictions disrupted in-person arts participation, increasing risks of social isolation and reduced community access. Prior research shows that many people engaged in home-based arts and cultural activities during lockdown, supporting emotional regulation, a sense of belonging, and social connection; however, little is known about how these shifts affected community arts organizations that serve artists with intellectual and/or developmental disabilities (IDD), a population disproportionately impacted by the pandemic and longstanding inequities. We examined how community-based arts organizations adapted programming for artists with IDD during the COVID-19 pandemic, including barriers and unanticipated outcomes relevant to equitable access and participation …

Eeg Signatures Of Motor Development In Early Childhood: A Systematic Review, Sonia Khurana, Ashwini Kulkarni, Thomas C. Bulea, Hunter J. Bennett

Rehabilitation Sciences Faculty Publications

Background

Early identification of motor developmental disorders is limited due to lack of objective neural markers that characterize typical neurodevelopmental patterns. This systematic review interprets and synthesizes existing evidence to propose a framework of EEG signatures associated with motor development in children aged 0-5 years, which may help inform future benchmarks for early assessment and intervention.

Methods

Following PRISMA guidelines, we searched published and gray literature across five databases between 2000 and 2025 (registered protocol). Included studies examined EEG during task-based, resting-state, or sleep studies linked to motor milestones, task performance, or standardized motor assessments. Study quality was assessed using …

Walking It Off: Habituation Of Gait At Virtual High Elevation, Kelly Poretti, Toby J. Ellmers, Christopher K. Rhea, Tiphanie Raffegeau

Rehabilitation Sciences Faculty Publications

Introduction: Fear and anxiety about falling can disrupt gait control, leading to activity restriction and increased fall risk in older adults. VR can be used to induce postural threat (e.g., by simulating high elevation settings) within a controlled environment, inducing fall-related anxiety and cautious gait (i.e. slower, shorter steps) in young and older adults. However, it is unknown how emotional and motor responses to VR postural threat habituate across time because existing studies feature short exposures (10 seconds or less). Before VR-induced postural threat can be translated into an intervention, it is critical to understand threat-related gait habituation across time. …

Hierarchical Clustering Reveals Multilevel Structure For Multifactorial Assessment In Community-Dwelling Older Adults, Brittany S. Samulski, Ashwini Kulkarni, Neda Moghim, Ross Gore, Soumya Banerjee, Christopher K. Rhea

Rehabilitation Sciences Faculty Publications

Multifactorial falls assessment is recommended for older adults at elevated risk but can generate numerous potentially overlapping measurements, increasing testing burden despite potentially diminishing informational returns as correlated measures are added. Characterizing how measures covary may inform subsequent efforts to evaluate more efficient assessment procedures. Community-dwelling older adults (n = 298) completed a single-visit assessment including the Physiological Profile Assessment (PPA), preferred- and maximal-speed walking, Montreal Cognitive Assessment (MoCA), and Modified Falls Efficacy Scale (MFES). Hierarchical agglomerative clustering was applied to 51 variables. Dendrogram fidelity, cluster separation, and resampling stability were evaluated using the cophenetic correlation coefficient (CCC), silhouette width, …

Organized Sports-Based Interventions And Motor Outcomes In Children Diagnosed With Autism Spectrum Disorder: A Systematic Review, Kailash Ram, Maeren Hill, Caitlyn Stewart, Kaitlin P. Hardy Md, Sonia Khurana

Rehabilitation Sciences Faculty Publications

Aim

To evaluate the effectiveness of organized sports-based interventions on motor outcomes in children with autism spectrum disorder (ASD).

Method

Four databases were searched from inception to November 2025 for randomized controlled trials (RCTs) and non-randomized controlled trials (NRCTs) reporting motor outcomes of organized sports-based interventions in children with ASD. Risk of bias was evaluated using ROB-2 (Cochrane Risk of Bias Tool, Version Two) for RCTs and ROBINS-I (Risk Of Bias In Non-randomized Studies - of Interventions) for NRCTs.

Results

Eleven studies (six RCTs, five NRCTs) were included and categorized as martial arts (n = 5), aquatic training (n = …

Lunch Shaming And The Right To Privacy, Ira P. Robbins

Scholarly Articles in Law Reviews & Journals

Lunch shaming is the practice of penalizing students who cannot afford to pay for their meals, resulting in them being denied food, served alternative meals, or publicly identified. The origins of lunch shaming can be traced to the financial pressures faced by school districts that struggle to balance tight budgets with the mandate to provide free or reduced-price meals to eligible students. Despite legislative efforts and advocacy campaigns aimed at mitigating the problems associated with lunch shaming, the practice persists, exacerbated by rising food costs and the expiration of pandemic-era food programs.

Many law journal and other articles have correctly …

A Computational Approach To Graduated Centrifuge Profiles For Partial Gravity Planetary Environments, Cabell W. Jones

Mechanical & Aerospace Engineering Faculty Publications

Missions such as NASA’s Artemis and SpaceX’s Starship aspire towards creating permanent settlements beyond Earth. In order to achieve this goal, it must be considered that the gravity present on planetary surfaces such as the Moon (0.165 g) and Mars (0.378 g) may be insufficient to support human physiology for long term habitation. On near-Earth missions, issues such as muscular atrophy, neuro-ocular changes, cardiopulmonary variations, and bone mineral density loss have been observed proportional to the duration spent in microgravity. Further studies have suggested that the severity of these conditions scales linearly with decreasing gravity, meaning that astronaut health can …

Multihoming And Single-Homing Complementors' Responses To Intensified Between-Platform Competition: Evidence From The Youtube–Twitch Rivalry, Niloofar Abolfathi

Research Collection Lee Kong Chian School Of Business

Research Summary: This paper examines how heterogeneous YouTube content creators-specifically, single-homing and multihoming channels-respond to a sudden increase in the exposure of the rival platform, Twitch. Contrary to expectations, I find that multihoming channels reduce their content creation efforts and underperform relative to single-homers. To make sense of these surprising results, I develop a formal model that characterizes the strategic behavior of different types of complementors operating across two platforms with varying levels of user exposure. The model offers a plausible explanation for the observed empirical patterns, suggesting that intensified competition between platforms, as a consequence of their changing exposure, …

More Than A Seat At The Table: Examining How Psychological Safety, Identity Representation, And Leadership Accountability Impact African American Women In Global Workplace Environments, Shelbi Chandler

Theses and Dissertations

This qualitative phenomenological study examined the lived experiences of African American women working in corporate technology environments, with particular attention to psychological safety, representation, and systemic barriers to advancement. Despite increased organizational commitments to equity and inclusion, research continues to demonstrate that Black women encounter persistent intersectional barriers shaped by race and gender within professional settings (Erskine et al., 2021; Field et al., 2023; Roberson, 2019). Guided by Du Bois’s (2008) theory of double consciousness, Goosby Smith’s (2014a) Ubuntic inclusion framework, and appreciative inquiry (AI; Cooperrider & Whitney, 2005), this study explored how African American women interpret, navigate, and respond …

The Effects Of Anxiety On Adult Athletes And Approaches To Improving Performance And Well-Being, Taylor Glaspie-Walton

Theses and Dissertations

This systematic review examined the complex relationship between anxiety and sports performance in adult athletes, along with exploring effective approaches for enhancing both performance and psychological well-being. Through analysis of 18 studies spanning diverse sports and competitive levels, this research identifies key factors that influence anxiety responses and performance outcomes. Findings revealed that competition level, performance-goal discrepancies, and injury recovery significantly impact anxiety levels, with athletes' interpretations of anxiety symptoms proving more influential than symptom intensity alone. The research demonstrates that mental toughness and self-efficacy function as fundamental psychological resources, though their impact appears to plateau at elite competitive levels. …