Digital Commons Network^™

Help-Seeking Among Early Adolescents Who Use Physical Peer Violence, Kelli Franco, Elizabeth Baumler, Leila Wood, Heidi Adams Rueda, Jeffrey R Temple

Faculty, Staff and Student Publications

Despite accumulating research on help-seeking among violence victims, little is known about help-seeking among youth who use violence. In a racially and ethnically diverse sample of early adolescents (N=2,676; 50.3% female; Mage=12.67), participants self-reported physical bullying, physical fighting, physical dating violence perpetration, and help-seeking intentions over the past year. T-tests and one-way ANOVAs examined help-seeking by sex and race, respectively. Prevalence and comparisons of help-seeking across youth with and without any violence were examined. Youth who used any physical peer violence (n=965) reported lower help-seeking intentions than their peers, and among violent youth, males reported …

Dna Methylation Markers Of Insulin Resistance Surrogate Measures In The Atherosclerosis Risk In Communities (Aric) Study, Elizabeth Selvin, Chloé Sarnowski

Faculty, Staff and Student Publications

Insulin resistance (IR) is a risk factor for cardiovascular diseases and type 2 diabetes. Associations between DNA methylation (DNAm) and IR have been less studied in African ancestry (AA) populations than those of European ancestry (EA). We aimed to identify associations between whole blood DNAm and IR in up to 1,811 AA and 964 EA participants from the Atherosclerosis Risk in Communities (ARIC) study. We quantified IR using three surrogate measures: the homeostasis model assessment of insulin resistance (HOMA-IR), the triglyceride-glucose index (TyG), and the triglyceride glucose-body mass index (TyG-BMI). We used ancestry-stratified linear regression models to conduct epigenome-wide association …

Allogeneic Bone Marrow-Derived Mesenchymal Stem Cells For Parkinson's Disease: A Randomized Trial., Mya C Schiess, Jessika Suescun, Juan D Martinez-Lemus, Charles Green, Tia S Thomas, Mohammad Shahnawaz, Emily Tharp, Nikunj B Satani, Jerome G Saltarrelli, Christopher Adams, Marie-Francoise Doursout, Vanessa Thyne, Rula Abuamouneh, Elsa M Rodarte, Sean I Savitz, Timothy M Ellmore

Faculty, Staff and Student Publications

Background: Neuroinflammation contributes to Parkinson's disease (PD) progression and motor dysfunction. Allogeneic human mesenchymal stem cells (allo-hMSCs) may reduce neuroinflammation and improve motor symptoms.

Objectives: To evaluate the efficacy of repeated intravenous doses of 10 × 106/kg allo-hMSCs in improving motor symptoms in patients with PD (PwP).

Methods: In this phase 2, randomized, placebo-controlled trial (November 2020-July 2023), mild-to-moderate PwP received either three allo-hMSC infusions, one placebo followed by two allo-hMSC infusions, or three placebo infusions at 18-week intervals. Follow-up lasted 88 weeks. The primary outcome was a >70% posterior probability (PP) of a difference in the proportion of participants …

Evaluating Energy Transition Winners And Losers: Are Algae Biofuels Desirable, Feasible, And Viable?, Michelle M. Arnold

All Graduate Theses and Dissertations, Fall 2023 to Present

Climate change, environmental degradation, finite resources, and the uneven distribution of energy access all points to an urgent need for a global energy transition. But making that transition responsibly requires more than enthusiasm for “green” solutions—it demands careful evaluation of which energy sources are truly worth investing in. This dissertation develops a practical decision-making framework to help policymakers, scientists, and the public answer three foundational questions about any new energy technology: Is it desirable? Is it feasible? Is it viable? By systematically weighing public narratives, biophysical constraints, and patterns of innovation, the framework aims to prevent wasted time, funding, and …

Prospective Trial Of Cerebrospinal Fluid Filtration After Aneurysmal Subarachnoid Hemorrhage Via Lumbar Catheter Extension (Pillar-Xt), Spiros L Blackburn, Marc A Babi, Andrew W Grande, Omar A Choudhri, Erik F Hauck, Christopher P Kellner, Michael C Giordano, Shivanand P Lad, Aaron R Mccabe

Faculty, Staff and Student Publications

Background: There is a growing consensus that blood in the cerebrospinal fluid (CSF) is deleterious to outcomes in patients with aneurysmal subarachnoid hemorrhage. The extracorporeal filtration of subarachnoid hemorrhage via spinal catheter extension study evaluated the safety, tolerability, and filtration curve of blood and its lysis products from hemorrhagic CSF using the Neurapheresis CSF Management System.

Methods: After aneurysm repair, a dual-lumen intrathecal catheter was inserted into the study participant's spinal canal. CSF was extracorporeally filtered for up to 72 h, removing blood products from the lumbar cistern, and reintroducing filtered CSF to the thoracic subarachnoid space. Neurological examinations were …

Short-Term Preeclampsia Prediction: Cutoff Variations For Sflt-1/Plgf In U.S. Patients With Or Without Hypertensive Disorders, Yaxin Li, Kristen Cagino, Jim Yee, Caroline Andy, Dajana Borova, Ayush Shah, Isla Racine, Tracy B Grossman, Zhen Zhao

Faculty, Staff and Student Publications

Background: Preeclampsia (PE) is a complex disorder with significant maternal and fetal risks. The soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) ratio shows promise as a diagnostic tool, but its adoption in the U.S. remains limited due to the lack of accessible testing platforms, U.S.-based studies, and evidence-based implementation guidelines.

Patients/materials and methods: We conducted a cohort study to evaluate the sFlt-1/PlGF ratio for predicting PE within two weeks among pregnant individuals ≥18 years, ≥20 weeks gestation. Serum samples were obtained from routine prenatal visits or triage evaluations. sFlt-1/PlGF ratios were measured using Roche Elecsys assays, and …

Extracellular Domain Shedding Of Trop2 Activates Egfr Signaling To Drive Prostate Cancer Metastasis, Shiqin Liu, En-Chi Hsu, Merve Aslan, Fernando Garcia-Marques, Michelle Shen, Alifiani B Hartono, Francisco Solano, Kewei Le, Hyeonji Hwang, Chung S Lee, Abel Bermudez, Rosalie Nolley, Donna M Peehl, James D Brooks, Michael A Liss, Sharon J Pitteri, Tanya Stoyanova

Faculty, Staff and Student Publications

UNLABELLED: Metastasis is the main cause of prostate cancer-associated deaths, highlighting the urgent need to determine the mechanisms underlying prostate cancer progression. TROP2 (also known as tumor-associated calcium signal transducer 2) is an oncogenic transmembrane surface protein that is highly expressed in metastatic prostate cancer. Naturally occurring cleavage of TROP2 leads to a release of the TROP2 extracellular domain (TECD) into the extracellular environment. In this study, we identified an important functional role of TECD in prostate cancer metastasis. TECD was detectable in media from prostate cancer cells and serum from patients with clinically significant prostate cancer. Although shed TECD …

Prone Percutaneous Jungbluth For Reduction Of Irreducible Posterior Pelvic Ring Injuries: A Technical Trick, Joseph M Radley, Jonathan A Copp, Daniel S Gloekler, Jonathan G Eastman

Faculty, Staff and Student Publications

Unstable pelvic ring injuries represent a challenge due to the complex anatomy. Further, surgical access to the pelvic ring is altered by patient positioning in the supine versus prone position. Certain injury patterns present with the posterior pelvis in a fixed displaced position. These injuries can be exceedingly challenging to reduce from a supine position. In the prone position, these injuries can be reduced more directly with an open approach, but this is associated with wound healing complications. The technical trick herein demonstrated a successful technique utilizing a large Jungbluth clamp percutaneously applied to the posterior superior iliac spines with …

Assessment Of Postoperative Range Of Motion In Pediatric Patients Undergoing Surgical Reduction And Fixation Of Lateral Condyle Fractures, Gabrielle Rogie, Timothy Borden, Lindsay Crawford, Surya Mundluru, Brennan Roper, Rohini Mahajan Vanodia, Shiraz Younas

Faculty, Staff and Student Publications

Purpose: The objective of this study was to evaluate the outcomes of various methods of fixation for pediatric lateral condyle fractures. The null hypothesis was that there would be no difference between the three treatment groups and time of return to the full range of motion.

Method: There were three fixation groups-Algemeinshaft fur osteosynthesegragen (AO) cannulated screws (n = 11), buried Steinmann pins (n = 13), and unburied Steinmann pins (n = 36). Variables evaluated were time to return to full range of motion of the elbow, whether therapy was required, average number of follow-up visits, fracture …

Trends In Preservation Rhinoplasty Publications: A Bibliometric Analysis Of Presented Data Originality, Rakan Saadoun, W Katherine Kao, Tang Ho

Faculty, Staff and Student Publications

Background: Recent literature on dorsal preservation rhinoplasty (DPR) has seen a resurgence. This study performs a bibliometric analysis of publications and co-authorships within this research area, considering factors such as gender, country of origin, international collaboration, and the originality of the presented data.

Methods: The PubMed-indexed literature on DPR from 2018 to 2024 was extracted and reviewed, limited to English publications. Descriptive statistics were performed regarding the contributors by gender, country, publishing journal, authorship rank, and department of affiliation. Association tests were used to determine the association between the originality of the data presented and the affiliation's country and department. …

Efficacy Of Platelet Rich Plasma Versus Placebo For Improvement In Olfactory Function In Adults With Olfactory Dysfunction: A Systematic Review And Meta-Analysis, Ali B Jafar, Ghabrielle Almeida, Fatima Al Mousawi, Eric Delgado Rendon, Amber U Luong

Faculty, Staff and Student Publications

Background: Olfactory dysfunction significantly impairs quality of life. Conventional treatments such as corticosteroids and olfactory training offer limited and inconsistent efficacy. Platelet-rich plasma (PRP), a biologically active agent, has shown potential regenerative effects in olfactory neuroepithelium. This study systematically evaluates the efficacy of PRP compared to placebo in improving olfactory function.

Methods: A systematic review and meta-analysis was conducted according to PRISMA guidelines and was registered in PROSPERO (CRD 420251045079). The databases searched included PubMed, Scopus, Embase, Central, and Web of Science. Seven studies (four RCTs, three non-RCTs) involving 789 patients were included. Subjective and objective outcomes were extracted and …

Whipple Disease Initial Presentation As Supraclavicular Lymphadenopathy In A Patient With Rheumatoid Arthritis: A Diagnostic Challenge, Sara E Amin, Swati Gite, Audrey Wanger, Violeta Chavez, Jacob Armstrong, Beenu Thakral, Patricia Navarro, Jennifer Makhoul, Amer Wahed, Navneet Narula, Karan Saluja

Faculty, Staff and Student Publications

Whipple disease is a rare systemic disease caused by Tropheryma whipplei. It can present with a wide range of nonspecific symptoms that might overlap with underlying medical conditions, posing a diagnostic challenge. We present a 61-year-old man with a past medical history of rheumatoid arthritis and chronic inflammatory demyelinating polyneuropathy, who presented with persistent leukocytosis and supraclavicular lymphadenopathy. A positron emission tomography scan revealed hypermetabolic activity in the supraclavicular, abdominal, and pelvic lymph nodes along with a myocardial hypermetabolic lesion, concerning a lymphoproliferative disorder versus sarcoidosis. A supraclavicular lymph node excisional biopsy revealed complete architectural effacement by a diffuse foamy …

Developing Consensus For A More Provider-Friendly Next-Generation Sequencing Molecular Biomarker Report: A Joint Consensus Recommendation Of The Association For Molecular Pathology And College Of American Pathologists, Jane Gibson, Hanadi El Achi, Dana Altenburger, Noah Brown, Amy S Clark, Joshua Coleman, Rajyasree Emmadi, Amber M Fussell, Meera Hameed, Danielle Jordan, Jennifer Laudadio, Anthony Provenzano, Robyn L Temple-Smolkin, Christopher G Suciu

Faculty, Staff and Student Publications

Despite the increasing availability of next-generation sequencing (NGS) gene panel analysis for cancers, published reports suggest underutilization of testing, citing the shortage of credentialed professionals available to assist with the interpretation of test results among the key barriers. Obtaining a multidisciplinary consensus regarding a shared best practice NGS molecular biomarker reporting section template may facilitate introduction and/or increased testing for institutions that adopt similar report structures by improving report effectiveness and efficiency for both health care providers and laboratory professionals, leading to improved patient care. To address this challenge, the Association for Molecular Pathology convened a multidisciplinary collaborative expert working …

Alk5 Inhibitor Impact On Bleomycin-Induced Systemic Sclerosis Mouse Model Via Multifunctional Optical Coherence Tomography, Manmohan Singh, Matthew Fronheiser, Juliana Coculo, Shuyan Du, Shervin Assassi, Kirill V Larin

Faculty, Staff and Student Publications

Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by fibrosis, vascular dysfunction, and immune dysregulation, leading to significant morbidity and mortality. Noninvasive imaging techniques are critical for monitoring disease progression and evaluating therapeutic interventions. This study investigates the technical feasibility of multifunctional optical coherence tomography (OCT)-based methods for longitudinal assessment of skin thickness, stiffness, and microvasculature in a murine SSc model as a translational, noninvasive, and quantitative method to study disease progression and treatment response. Our findings demonstrate significant structural, biomechanical, and vascular changes in the skin's stiffness, indicative of fibrosis, a hallmark of SSc. The application of SB …

Impact Of Propofol Or Sevoflurane On The Renoprotective Effect Of Remote Ischaemic Preconditioning In Cardiac Surgery: The Hypnorenalrip Randomised Clinical Trial, Raphael Weiss

Faculty, Staff and Student Publications

Background: Remote ischaemic preconditioning (RIPC) might reduce acute kidney injury after cardiac surgery. Protective effects appear to be restricted to patients with early and transient increases in two cell cycle arrest markers, tissue inhibitor of metalloproteinases-2 (TIMP-2) and insulin-like growth factor-binding protein 7 (IGFBP7), in urine. Studies suggest that propofol can attenuate the preconditioning effect on the myocardium. This study investigated whether propofol diminishes the renoprotective effect associated with the early transient increases in TIMP-2 and IGFBP7.

Methods: This was a single-centre, prospective randomised double-blind 2×2 factorial clinical trial of high-risk patients undergoing cardiac surgery. Patients were randomised to receive …

Understanding Impact Of Starter Culture Blends On The Ph Variation In Cheddar Cheese During Early Aging, Samuel J. Clarke

All Graduate Theses and Dissertations, Fall 2023 to Present

Consumer expectations govern what is acceptable when it comes to the flavor, texture, and color of the cheese. These quality attributes of cheese are all influenced by the pH of the cheese which is in turn controlled by the acid production of the starter lactic acid bacteria (SLAB) used to make cheese. Whatever the final pH of the cheese is, is what determines the quality of the cheese. Unfortunately, there are some Cheddar cheese manufacturers that have observed pH variation during the early aging of their cheeses. We hypothesize that the addition of thermophilic, fast-acid producing bacteria, like Streptococcus thermophilus …

Developing Standardized Testing Datasets For Benchmarking Automated Quality Control Algorithm Performance With Aquatic Sensor Data, Ehsan Kahrizi

All Graduate Theses and Dissertations, Fall 2023 to Present

Advances in water monitoring technologies have led to a large increase in the amount of data collected from rivers, lakes, and other water systems. However, ensuring that these data are accurate and reliable remains a major challenge. Traditional data quality checks are done manually by a technician, which can be slow, inconsistent, and not practical for real-time monitoring. This research addresses these challenges by developing standardized datasets for testing computer-based methods that automatically detect and correct errors in water data. Using information from the Logan River Observatory in northern Utah, we created a step-by-step process to identify, categorize, and label …

Cognitive Dynamics In Undergraduate Engineering Education: Effects Of Need For Cognitive Closure And Achievement Goal Orientation On Cognitive Engagement, Zain Ul Abideen

All Graduate Theses and Dissertations, Fall 2023 to Present

Cognitive and motivational factors play an important role in students’ engagement during problem-solving, which can lead to academic and professional success. Among these factors, Need for cognitive closure (NFCC) and achievement goal orientation (AGO) have been studied extensively individually, but their interaction and impact on engineering students’ problem-solving is still not explored. NFCC refers to the person’s desire for quick answers, and AGO is the student’s approach to learning and success. This research investigated the impact of NFCC on gender and engineering major, and the relation between NFCC (five facets) and AGO (Mastery, Performance) at their different levels. Additionally, this …

Golden Eagle Predation Of Greater Sage-Grouse On Diamond Mountain Plateau, Victoria E. Thorpe

All Graduate Theses and Dissertations, Fall 2023 to Present

Predation and the perceived risk of predation can have major impacts on prey populations. Golden Eagles are considered one of the main predators of adult greater sage-grouse. Sage-grouse populations have been declining for decades throughout the West and wildlife managers are concerned about the impacts of golden eagles on sage-grouse. We investigated the nonconsumptive effects of golden eagles on sage-grouse by conducting observational surveys for golden eagles, sage-grouse, and other predators at sage-grouse lek sites near Vernal, Utah during the sage-grouse breeding season from 2022–2024. Additionally, we examined the prevalence of sage-grouse in golden eagle diet using DNA metabarcoding of …

Design, Control, And Optimization Of Unfolding-Based Ac-Dc Topologies With Three-Port Resonant Converters For Electric Vehicle Battery Charging Applications, Aditya Zade

All Graduate Theses and Dissertations, Fall 2023 to Present

The global effort to reduce greenhouse gas emissions and reliance on fossil fuels has made electric mobility a cornerstone of sustainable transportation. This transition is driving demand for advanced charging infrastructure and more efficient power conversion systems. Power converters play a central role, not only in enabling reliable EV charging but also in integrating renewable energy sources with the grid. Because of the large amount of power involved, these converters must operate efficiently, reliably, and at low cost. Conventional high-power chargers often use two stages of conversion, which are effective but limited by size and energy losses. To overcome these …

Lagomorphs, Ungulates, And Predation: Exploring Interactions And Quantifying The Effect Of Lagomorph Herbivory In Rangelands, Shantell Marie Garrett

All Graduate Theses and Dissertations, Fall 2023 to Present

Rangelands are expansive ecosystems that make up more than 30% of the total surface land area in the contiguous United States. In the west, they are typically categorized as shrublands, grasslands or deserts with low precipitation. The vegetation communities consist largely of grasses and forbs and are thus widely used for livestock grazing. Despite their barren appearance, rangelands are diverse ecosystems that are home to a wide breadth of species.

The Henry Mountains, located in south central Utah, is one example of this system type. With their inspiring red-rock mesas and towering plateaus, this public land, managed by the Bureau …

Using Luminescence Of Quartz Temper From Archaeological Pottery To Infer Wildfire Intensity In The Southwestern Us, Brooklyn D. Dib

All Graduate Theses and Dissertations, Fall 2023 to Present

The size and frequency of wildfires have increased recently, impacting ecosystems, communities, and human health. This research uses the heat-sensitive luminescence signals of quartz sand temper within archaeological pottery to record past wildfire conditions. Pottery sherds, which are fragments of archaeological pottery, from the forest floor in sites in New Mexico and Arizona were collected from different fire contexts (no fire exposure, historical fires, prescribed burns, and modern wildfires). These forests are primarily Ponderosa Pine with a grassy understory. The interior sand grains of each sherd sample were analyzed using optically stimulated luminescence, which dates when the mineral grains were …

Privacy-By-Design: Case Studies In Interactive Record Linkage Using A Hybrid Human-Computer System, Theodoros Giannouchos, Qinbo Li, Adam D'Souza, Elmer V Bernstam, Jeffrey R Curtis, Alva O Ferdinand, Cason Schmit

Faculty, Staff and Student Publications

Objective: High-quality patient matching from several sources without a common identifier (ID) requires interactive record linkage (RL) using a hybrid human-computer system. MiNDFIRL (MInimum Necessary Disclosure For Interactive Record Linkage) is a hybrid prototype software system that facilitates maximizing linkage accuracy while minimizing information disclosure. We present and evaluate MiNDFIRL using two real-world case studies.

Materials and methods: Two user studies were conducted linking 10,000 data pairs from EHR data and 18,240 unique patient IDs from patient generated data. After automated RL, manual review was conducted by three teams of four reviewers (12 total) using MiNDFIRL to resolve potential matches …

The Deubiquitinating Enzyme Cezanne Stabilizes Brca1 By Counteracting Apc/C And Ube2s-Dependent Lys11-Linked Ubiquitination, Longqiang Wang, Xiao Wu, Atanu Paul, Jun Yao, Bin Wang

Faculty, Staff and Student Publications

The breast and ovarian tumor suppressor BRCA1 is a cell cycle-regulated protein and tumors with reduced BRCA1 protein level may share molecular features of BRCA1-mutant tumor and respond to PARPi therapy. Here, we identify that BRCA1 protein stability is controlled through ubiquitin lysine 11 (K11)-linkage modification under the regulation of Cezanne deubiquitinating enzyme, APC/C E3 ligase, and Ube2S E2 conjugating enzyme in a cell cycle-dependent manner. Cezanne-deficiency leads to increased BRCA1 K11-ubiquitination, decreased BRCA1 protein level, and increased cellular sensitivity to PARPi. The BRCA1 K11-linked ubiquitination is carried out through a degron on BRCA1 that is recognized by APC/C cofactor …

Tsunami Simulation And Boulder Transport Across Contrasting Coastal Geomorphologies In Sanriku, Japan, Storm Roberts, Daisuke Sugawara, Hidetoshi Masuda, Sarah Boulton

School of Geography, Earth and Environmental Sciences

Tsunami boulders serve as crucial indicators for reconstructing past tsunami events, yet their full transport process remains poorly understood. This study investigates tsunami boulder transport at two geomorphically distinct field sites in Japan affected by the 2011 tsunami, integrating field data with a validated tsunami simulation to track wave parameters at every transport stage. The simulation was validated against eyewitness accounts, local reports, and offshore GPS buoy data. Near the shoreline at the Settai site simulated flow velocities reached a maximum of 7.55 m/s, compared to 6.51 m/s at Hoshiyama beach. Inland at Settai, a maximum 15.56 m/s flow velocity …

Life Cycle Assessment Comparing Electric And Petrol-Powered Rigid Inflatable Boats For Recreational And Harbour-Master Applications, Amir Bordbar, Badr Moutik, Adam Kyte, Simon Ussher, Keri Collins, Marcin Roszkowski, Tony Wilson, Sarah Fear

School of Geography, Earth and Environmental Sciences

This study presents the first cradle-to-grave life cycle assessment (LCA), focusing exclusively on environmental impacts, comparing electric and petrol-powered rigid inflatable boats (RIBs) under low-usage recreational and high-usage harbour-master scenarios. The study follows ISO-compliant LCA methodology and emphasizes transparency in data and assumptions. Ten environmental impact categories were analysed, including global warming potential (GWP), particulate matter formation, acidification, eutrophication, ecotoxicity, and resource scarcity. Results show that switching to electric RIBs reduces GWP by 34 % for recreational and 52 % for harbour-master scenarios, despite higher production-phase impacts across all categories. The electric RIB delivers notable operational benefits in GWP and …

Light Or Acid? Suppressing Water Deactivation In Saf Production Via Phenyl-Mediated Charge Transfer In Wox/Zrox-Functionalised Pmos, Vannia C. Dos Santos-Durndell, Mark A. Isaacs, Jinesh C. Manayil, Lee J. Durndell

School of Geography, Earth and Environmental Sciences

The aviation sector contributes ∼2.5 % of global energy-related CO2 emissions, driving demand for sustainable aviation fuel production (SAF) from biomass. However, water, whether intrinsic or produced in situ, often drives on-stream catalyst deactivation, reducing efficiency and creating barriers to process scale-up. Here, we present an exciting new approach using WOx/ZrOx-functionalised periodic mesoporous organosilica (PMO) photocatalysts that exhibit exceptional stability and performance under aqueous conditions. The incorporation of bis(triethoxysilyl)benzene (BTSB) into the PMO framework not only enhances surface hydrophobicity and acidity but also strategically positions organic π-conjugated phenyl groups next to WOx/ZrOx active sites. These phenyl moieties act as conductive …

Tectonic Modulation Of Caldera Volcanism On The South Aegean Island Arc, A Metcalfe, Tim Druitt, Katharina Pank, Steffen Kutterolf, Jonas Preine, Sarah Beethe, Axel K. Schmitt, Christian Hübscher, Paraskevi Nomikou, Thomas A. Ronge, Carole Berthod, Hehe Chen, Shun Chiyonobu, Acacia Clark, Susan Debari, Ralf Gertisser, Raymond Johnston, Olga Koukousioura, Michael Manga, Molly Mccanta, Iona Mcintosh, Ally Peccia, Masako Tominaga, Yuzuru Yamamoto, Adam Woodhouse, Alexis Bernard, Tatiana Fernandez-Perez, Christopher Jones, Kumar Batuk Joshi, Günther Kletetschka

School of Geography, Earth and Environmental Sciences

Many highly hazardous, caldera-forming explosive eruptions occur in extensional tectonic regimes, but the role of lithospheric rifting in modulating caldera volcanism remains enigmatic. IODP Expedition 398 deep-drilled the volcano-sedimentary infills of submarine half-grabens around Santorini caldera on the continental South Aegean Volcanic Arc. Here we use the volcanic tephra archives to produce a high-resolution eruptive chronostratigraphy for Santorini, to ground-truth seismic stratigraphy, and to extract an integrated timeline of volcano-tectonic couplings. The rift basins contain several submarine volcaniclastic megabeds from the caldera-forming eruptions of Santorini and one from the Kos caldera. The thickest megabed succession is < 250,000 yrs old and lies on a seismic reflection onlap surface that records a phase of rapid rifting. Sedimentation lagged behind subsidence during this rifting phase, creating bathymetric troughs. Integrating submarine core-seismic and onland datasets, we propose that rifting may have driven the transition of Santorini from a prolonged state of effusive and minor explosive activity (∼550 – 250 ka) typical of arc stratovolcanoes to one of repeated caldera-forming eruptions (<250 ka). Rapid rifting may have amplified the normal internal dynamics of the magmatic system in three ways, driving the volcano into a sustained, highly explosive state: (1) an increase in the supply of mantle-derived basalt, (2) enhanced shearing, permeability, and melt percolation in the transcrustal magmatic system, and (3) the development of horizontally extensive magma reservoirs. Broadly simultaneous transitions into caldera-forming activity of the widely separated Santorini and Kos Volcanoes suggest that the two magmatic systems are linked by plate-scale lithospheric stresses.

Understanding The Sources And Variability Of Air Pollution In Northern High Latitudes: Using Formaldehyde (Hcho) As A Tracer, Tianlang Zhao

Chemistry and Biochemistry

Formaldehyde (HCHO) is a trace gas primarily found in the planetary boundary layer. It is a first-generation oxidation product of a wide range of volatile organic compounds (VOCs) during their reaction with hydroxyl radicals (OH) and serves as a key precursor for major air pollutants, including surface ozone (O3) and secondary organic aerosols (SOA). Despite its significance, HCHO remains poorly constrained in North America, particularly in the northern high latitudes. My Ph.D. research focuses on elucidating the variability of HCHO across the Arctic and the contiguous United States (CONUS), spanning temporal scales from diurnal cycles to interannual variability, and identifying …

Elucidating The Oxidation Mechanisms In Cr2alb2 Using Density Functional Theory And Thermodynamic Modeling, Ushan Asela Adhikarige

Theses and Dissertations

This thesis investigates the oxidation behavior of Cr2AlB2 surfaces using density functional theory calculations combined with thermodynamic modeling. Our analysis encompassed surface stability assessments, oxygen adsorption studies on various surfaces, and thermodynamic insights into oxidation mechanisms. Surface stability assessments reveal that the (010) surface terminated with an Al layer exhibits the lowest surface energy. Oxygen adsorption studies on the (010), (111), and (021) surfaces demonstrate strong dissociative adsorption with binding energies ranging from -4.72 to -4.22 eV depending on coverage. Thermodynamic analysis shows that elevated temperatures reduce oxidation favorability, while increased oxygen partial pressure enhances it. The study reveals that …