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Breeding Challenges In Apomictic Warm-Season Grasses, E C. Bashaw, P W. Voigt, B L. Burson May 2026

Breeding Challenges In Apomictic Warm-Season Grasses, E C. Bashaw, P W. Voigt, B L. Burson

IGC Proceedings (1977-2023)

Efforts to breed apomictic grasses met with little success in the past, but results of more recent research show significant progress with some species and new prospects for improving apomicts. Early research uncovered the cytological basis for apospory and diplospory, found the common apomictic mechanisms in grasses, and showed that apomixis is transmitted from pannt to offspring. Discovery of sexual or partially sexual (facultative apomicts) plants in several species formerly considered obligate apomicts allowed for hybridization and genetic studies. Results of subsequent research confirmed inheritance of apomixis, and data from the more conclusive studies indicate that method of reproduction …


Visualizing Ozone Pollution In The Denver Metro Area Using A Bioindicator Garden, Ella K. Mathews, Hillary Hamann, Julie Morris, Erica L. Larson May 2026

Visualizing Ozone Pollution In The Denver Metro Area Using A Bioindicator Garden, Ella K. Mathews, Hillary Hamann, Julie Morris, Erica L. Larson

DU Undergraduate Research Journal Archive

Since the industrial revolution, widespread fossil fuel combustion has significantly increased atmospheric pollution. The combustion of fossil fuels releases nitrogen oxides (NOx) and volatile organic compounds (VOCs), which form tropospheric (ground-level) ozone when exposed to sunlight. Ozone directly harms plants by disrupting their ability to absorb carbon dioxide, release oxygen, and carry out photosynthesis. Bioindicator species are plants that have visible responses to environmental conditions, such as ozone, and can act as “canaries in the coal mine,” indicating the health of their environment. In this study, we used a garden of ozone bioindicator species (ozone garden) as a cost-effective tool …


Du Undergraduate Showcase Abstracts: Research, Scholarship, And Creative Works, Sophia Wismar, Henry Staats, Allison Metzler, Chloe Puckett, Rachel Levine, Christa Kilpatrick, Scott Wolf, Joe Walsh, Grace Doolittle, John Engebreston, Zoe Lopez, Christopher Aaby, Audrey Duff, Timothy Sisk, Katelyn Lamberton, Angela Narayan, Gilkah Argueta, Habiba Samir, Girena Tesfazghi, Genet Kenore, Sinit Tesfamariam, Effley Brooks, Abi Newell, Megan Doherty, Natalie Baer, Lexi Blood, Talya Riciputi, Jessica Jimenez, Devin Hernandez, Lynn Clark, Taj Kumar, Sunil Kumar, Allen Rutman, Mira Pronobis, Tess Carson, Anna Sher, Frankie Stroud, Tamra Pearson D'Estree, Alyssa Wilson, Emily Melnick, Jenalee Doom, Yihang Gao, Gwendolyn Geiger, Noah Gettle, Scott Nichols, Clare Ayoub, Cara Dienno, Sunny Walker, Zoe Hansen, Maya Wheeler, Addison Rice, Patrick Martin, Sanjana Acharya, Daniel Mcintosh, Amanda Mckellips, Calli Cain, Justin Blake, Peter Sokol-Hessner, Natalie Miller, Max Weisbuch, Sophia Dellota, John Macikas, Charlotte Snow, Mark Siemens, Zoe Lynch, Alex Huffman, Prachi Shah, Jason Roney, Halcyon Levi, Nicole Herzog, Andrea Koly, Daniel Linseman, Annie London, Xi Yang, Avery Zwisler, Jane Smith, Chaz Contag, Michael Kerwin, Lucy Rand, Grace Schroeder, Michelle Rozenman, Nissa Tapper, Guiming Zhang, Mateo Mazariego-Halpern, Keith Meyer, Julie Do, Dakota Park-Ozee, Travis Herink, Kara Neu, Jonathan Plomin, Eve-Odine Duchaufour, Debbie Gale Mitchell, Tennyson Anderson-Stricklin, Lily Treitz, Samantha Rosenberger, Sierra Griffith, Finley Joseph, Daniel Sampson, Emmy Davis, Skyler Kasnoff, Evon Lopez, Vivian Nguyen, Cassy Young, Franklin Sellner, Martin Tobon, Ila Graham, Zach Billings, Holden Hedit, Decatur Boland, Paul Kosempel, Cory Chandler, Jay Mahoney, Sam Dragan, Susan Dagget, Yarrow Ator, Heidi Vuletich, Owen Weber, Andrew Kloeppel, Petersen Gray, Mandi Schaeffer-Fry, Razleen Bassra, Bryanna Rodriguez, Christina Blue, Taubie Sanders, Rachel Epstein, Luke Milburn, Camryn Evans, Ezra Martinez, Mary Westwood, Gabri Notov, Robin Tinghitella, Lilou Cabrol, Eli Barbour, Juliet Mendik, Selma Myers, Zac Wise, Noah Fahlin, Michelle Knowles, Abigail Hopper, Michael Greenberger, Romi Laclair, Sarah Watamura, Sabrina Efroymson, Casey Barker, Sydney Seltzer, Bryn Yehle, Jennifer Hoffman, Sara Garcia, Ryuka Nagamine, Trevor Briggs, Remy Le Boeuf, Elena Krone, Eileen Farrell, Regan O'Rourke, Elena Roel, Greg Mortimer, Ali Ayoub, Stefani Langehennig, Caitlin Turk, Logan Scmid, Stefan Chavez-Norgaard, Karen Kim, Tatiana Peccedi, Courtney Cassidy, John Sebesta, Rhianna Lewis, Janice Bening-Lacek, Vivian Lawless, Mckenna Hanson, Jeffrey Amidon, Riya Joshi, Ram Ambre, Brady Worrell, Perrin Schneider, Ali Azadani, Brooke Agulnek, Lyndsie Salvagio, Elise Siemanowki, Yan Qin, Andre Allen, Melodie Nguyen, Megan Livengood, Abby Reams, Saffron Hartreeve, Bri Wylie, Sarah Brookman, Mariah Loiacono, Green Russo, Abhia Lodhi, Gabrielle Welsh, Nika Spehar, Shahked Levin, Evrim Baykal, Kimberly Chiew, Jocelyn Torres, Kailey Hicks, Mykaela Tanino-Springsteen, Audrey Bellows, Akam Chahal, Madeline Tepper, Shannon Murphy, Alexa Fonseca, Deborah Han, Cassandra Perez, Oluwatoyin Alaba, Julia Roncoroni, Vy Nguyen, Nana Burn, Sarah Sasse, Rubin Tuder, Anthony Gerber, Nancy Lorenzon, Christine Vohwinkel, Camryn Gunter, Tristan Weber, Sam Rommel, Brian Michel, Muskan Fatima, Alannah Oleson, Kira Frey, Edward Garrido, Beckett Morris, Kerstin Haring, Drew Middleton, Abigail Walpert, Liam Dee, Gabby Ishaw, Cole Carnes, Maddie Weiser, Claire Fox, Valeriia Vlasenko, Kateri Mcrae, Riley Smith, Abigail Templin, Kushani Rajapaksha May 2026

Du Undergraduate Showcase Abstracts: Research, Scholarship, And Creative Works, Sophia Wismar, Henry Staats, Allison Metzler, Chloe Puckett, Rachel Levine, Christa Kilpatrick, Scott Wolf, Joe Walsh, Grace Doolittle, John Engebreston, Zoe Lopez, Christopher Aaby, Audrey Duff, Timothy Sisk, Katelyn Lamberton, Angela Narayan, Gilkah Argueta, Habiba Samir, Girena Tesfazghi, Genet Kenore, Sinit Tesfamariam, Effley Brooks, Abi Newell, Megan Doherty, Natalie Baer, Lexi Blood, Talya Riciputi, Jessica Jimenez, Devin Hernandez, Lynn Clark, Taj Kumar, Sunil Kumar, Allen Rutman, Mira Pronobis, Tess Carson, Anna Sher, Frankie Stroud, Tamra Pearson D'Estree, Alyssa Wilson, Emily Melnick, Jenalee Doom, Yihang Gao, Gwendolyn Geiger, Noah Gettle, Scott Nichols, Clare Ayoub, Cara Dienno, Sunny Walker, Zoe Hansen, Maya Wheeler, Addison Rice, Patrick Martin, Sanjana Acharya, Daniel Mcintosh, Amanda Mckellips, Calli Cain, Justin Blake, Peter Sokol-Hessner, Natalie Miller, Max Weisbuch, Sophia Dellota, John Macikas, Charlotte Snow, Mark Siemens, Zoe Lynch, Alex Huffman, Prachi Shah, Jason Roney, Halcyon Levi, Nicole Herzog, Andrea Koly, Daniel Linseman, Annie London, Xi Yang, Avery Zwisler, Jane Smith, Chaz Contag, Michael Kerwin, Lucy Rand, Grace Schroeder, Michelle Rozenman, Nissa Tapper, Guiming Zhang, Mateo Mazariego-Halpern, Keith Meyer, Julie Do, Dakota Park-Ozee, Travis Herink, Kara Neu, Jonathan Plomin, Eve-Odine Duchaufour, Debbie Gale Mitchell, Tennyson Anderson-Stricklin, Lily Treitz, Samantha Rosenberger, Sierra Griffith, Finley Joseph, Daniel Sampson, Emmy Davis, Skyler Kasnoff, Evon Lopez, Vivian Nguyen, Cassy Young, Franklin Sellner, Martin Tobon, Ila Graham, Zach Billings, Holden Hedit, Decatur Boland, Paul Kosempel, Cory Chandler, Jay Mahoney, Sam Dragan, Susan Dagget, Yarrow Ator, Heidi Vuletich, Owen Weber, Andrew Kloeppel, Petersen Gray, Mandi Schaeffer-Fry, Razleen Bassra, Bryanna Rodriguez, Christina Blue, Taubie Sanders, Rachel Epstein, Luke Milburn, Camryn Evans, Ezra Martinez, Mary Westwood, Gabri Notov, Robin Tinghitella, Lilou Cabrol, Eli Barbour, Juliet Mendik, Selma Myers, Zac Wise, Noah Fahlin, Michelle Knowles, Abigail Hopper, Michael Greenberger, Romi Laclair, Sarah Watamura, Sabrina Efroymson, Casey Barker, Sydney Seltzer, Bryn Yehle, Jennifer Hoffman, Sara Garcia, Ryuka Nagamine, Trevor Briggs, Remy Le Boeuf, Elena Krone, Eileen Farrell, Regan O'Rourke, Elena Roel, Greg Mortimer, Ali Ayoub, Stefani Langehennig, Caitlin Turk, Logan Scmid, Stefan Chavez-Norgaard, Karen Kim, Tatiana Peccedi, Courtney Cassidy, John Sebesta, Rhianna Lewis, Janice Bening-Lacek, Vivian Lawless, Mckenna Hanson, Jeffrey Amidon, Riya Joshi, Ram Ambre, Brady Worrell, Perrin Schneider, Ali Azadani, Brooke Agulnek, Lyndsie Salvagio, Elise Siemanowki, Yan Qin, Andre Allen, Melodie Nguyen, Megan Livengood, Abby Reams, Saffron Hartreeve, Bri Wylie, Sarah Brookman, Mariah Loiacono, Green Russo, Abhia Lodhi, Gabrielle Welsh, Nika Spehar, Shahked Levin, Evrim Baykal, Kimberly Chiew, Jocelyn Torres, Kailey Hicks, Mykaela Tanino-Springsteen, Audrey Bellows, Akam Chahal, Madeline Tepper, Shannon Murphy, Alexa Fonseca, Deborah Han, Cassandra Perez, Oluwatoyin Alaba, Julia Roncoroni, Vy Nguyen, Nana Burn, Sarah Sasse, Rubin Tuder, Anthony Gerber, Nancy Lorenzon, Christine Vohwinkel, Camryn Gunter, Tristan Weber, Sam Rommel, Brian Michel, Muskan Fatima, Alannah Oleson, Kira Frey, Edward Garrido, Beckett Morris, Kerstin Haring, Drew Middleton, Abigail Walpert, Liam Dee, Gabby Ishaw, Cole Carnes, Maddie Weiser, Claire Fox, Valeriia Vlasenko, Kateri Mcrae, Riley Smith, Abigail Templin, Kushani Rajapaksha

DU Undergraduate Research Journal Archive

Abstracts from the DU Undergraduate Research Showcase.


Panda-Plus-Bench: A Clinical Benchmark For Evaluating The Robustness Of Ai Foundation Models In Prostate Cancer Diagnosis, Joshua L. Ebbert, Dennis Della Corte May 2026

Panda-Plus-Bench: A Clinical Benchmark For Evaluating The Robustness Of Ai Foundation Models In Prostate Cancer Diagnosis, Joshua L. Ebbert, Dennis Della Corte

Faculty Publications

Artificial intelligence foundation models are increasingly deployed for prostate cancer Gleason grading, where GP3/GP4 distinction directly impacts treatment decisions (active surveillance vs. intervention). However, these models may achieve high validation accuracy by learning specimen-specific artifacts rather than generalizable biological features, limiting real-world clinical utility. We introduce PANDA-PLUS-Bench, a curated benchmark dataset derived from expertly annotated prostate biopsies designed specifically to quantify this failure mode. The benchmark comprises nine carefully selected whole slide images from nine unique patients containing diverse Gleason patterns, with non-overlapping tissue patches extracted at both 512 × 512 and 224 × 224-pixel resolutions across eight augmentation conditions. …


Backscattering By Particles Of Sizes <0.2 Μm In Seawater, Xiaodong Zhang, Yuanheng Xiong May 2026

Backscattering By Particles Of Sizes <0.2 Μm In Seawater, Xiaodong Zhang, Yuanheng Xiong

Faculty Publications

We measured the angular scattering functions at 517 nm in different size fractions, including bulk and very small particles (VSP for diameters <0.2 μm), in a variety of waters ranging from coasts to open oceans and from surface to depths as deep as 3,000 m. The measurements revealed a strong covariation in backscattering between VSP and bulk particle populations. The fractional contribution by VSP decreases from 60% in clear oceanic water where bulk particle backscattering coefficient bbp is on the order of 0.001 m−1 to <2% in turbid coastal water where bbp ∼0.1 m−1. An empirical model is developed (r2 = 0.89) to estimate bbp for VSP from the bulk bbp, which can now be routinely obtained from satellite observations.


Traveling Wave Fronts For Sir Epidemic Models With Nonlocal Dispersal And Delayed Effects, Ashley Evette Embry May 2026

Traveling Wave Fronts For Sir Epidemic Models With Nonlocal Dispersal And Delayed Effects, Ashley Evette Embry

Theses and Dissertations

This dissertation investigates traveling wave solutions for two classes of delayed nonlocal dispersal susceptible--infected--recovered (SIR) epidemic models incorporating biologically realistic mechanisms such as delayed infectivity, delayed dispersal, nonlocal transmission, demographic turnover, and nonlinear incidence effects. These models extend classical spatial epidemic frameworks by allowing long-range population movement through nonlocal dispersal operators and incorporating temporal memory into both diffusion and transmission processes. The primary objective is to establish the existence of traveling wave solutions connecting disease-free equilibria to endemic states and to characterize threshold conditions governing epidemic propagation. The simultaneous presence of nonlocal dispersal, multiple delays, and non-monotone nonlinear incidence terms …


Evaluating Soil Health And Crop Yield In Louisiana Agricultural Systems: Impacts Of Best Management Practices And Prediction Models, Hector J. Mendoza Lagos May 2026

Evaluating Soil Health And Crop Yield In Louisiana Agricultural Systems: Impacts Of Best Management Practices And Prediction Models, Hector J. Mendoza Lagos

LSU Doctoral Dissertations

The adoption of conservation management practices is critical for improving soil health, enhancing nutrient use efficiency, and sustaining crop productivity in row crop systems in Louisiana. This study evaluated the role of conservation agronomic practices, soil biochemical indicators, and machine learning predictive models to improve soil nutrient dynamics, soil health indicators, microbial communities (MC), and crop productivity on a corn (Zea mays L.) research plot scale and in a commercial forty-hectare cotton (Gassypium hirsutum L.)-corn-soybean (Glycine max L.) rotation system in northeast Louisiana. The objectives of the study were to evaluate soil nutrient dynamics and MCs under …


High-Throughput Robotic Ethanol Inhibition Assays For Engineered Thermophilic Biofuel Strains, Kevin He, Daniel Olson, Marybeth Maloney, Anthony Lanahan May 2026

High-Throughput Robotic Ethanol Inhibition Assays For Engineered Thermophilic Biofuel Strains, Kevin He, Daniel Olson, Marybeth Maloney, Anthony Lanahan

Wetterhahn Science Symposium Posters

Ethanol stress assays are commonly used to evaluate microbial tolerance, metabolic adaptation, and fermentation performance. However, manual liquid handling introduces variability across replicate wells and small-volume pipetting steps, limiting reproducibility and throughput. This study developed an automated OT-2 robotic workflow to generate replicated ethanol concentration gradients for high-throughput inhibition assays in engineered thermophilic biofuel strains. Kinetic plate-reader measurements were used to quantify ethanol-dependent growth responses under anaerobic fermentation conditions. The reasearch question is: How do engineered thermophilic biofuel strains differ in ethanol-dependent growth inhibition under anaerobic fermentation conditions, and can automated robotic assays improve the reproducibility of these measurements? Can …


Short Peptoid Capping Ligands Stabilize Dispersion Of Gold Nanospheres In Aqueous Solutions, Hanna G. Goldberg, Isabella K. Matusich, Jack M. Petersen, Nikhila Raman, Joseph C. Hong, Gabriela Edler, Daniel K. Tanaka, Jwwad M. Javed, Amelia A. Fuller May 2026

Short Peptoid Capping Ligands Stabilize Dispersion Of Gold Nanospheres In Aqueous Solutions, Hanna G. Goldberg, Isabella K. Matusich, Jack M. Petersen, Nikhila Raman, Joseph C. Hong, Gabriela Edler, Daniel K. Tanaka, Jwwad M. Javed, Amelia A. Fuller

Chemistry and Biochemistry

Surface functionalization of colloidal gold nanoparticles with capping ligands is critical for controlling their dispersive stability and for introducing application-specific moieties. Peptoids (N-substituted glycine oligomers) are useful candidates for study as capping ligands owing to their straightforward preparation and their biocompatibility. In this work, we have prepared a library of five-residue peptoids and evaluated them as capping ligands for 10 nm gold nanospheres. Our findings revealed important sequence features of peptoids that stabilize nanosphere colloidal dispersions in a range of aqueous conditions that vary in ionic strength and pH. We have also characterized the sizes and surface charges of peptoid-capped …


Enhanced Population Mean Estimation Using An Exponential Estimator With Known Medians Of Dual Auxiliary Variables Within A Neutrosophic Approach: Applications In Agricultural Yield Prediction, Anchal Yadav, Mukesh Kumar May 2026

Enhanced Population Mean Estimation Using An Exponential Estimator With Known Medians Of Dual Auxiliary Variables Within A Neutrosophic Approach: Applications In Agricultural Yield Prediction, Anchal Yadav, Mukesh Kumar

Neutrosophic Systems with Applications

In classical statistical theory, estimation of population parameters is generally carried out under the assumption that all observed data are precise, complete, and free from ambiguity. However, in many practical and real-world situations, data often deviate from these ideal conditions and instead appear in vague, uncertain, or interval-valued forms. Such imperfections reduce the effectiveness of traditional estimation techniques and motivate the development of more flexible and robust methodologies. To address these challenges, several improved estimators, particularly neutrosophic ratio-type estimators and their advanced extensions, have been proposed in recent literature. In this study, a new estimator known as the two auxiliary …


Epileptic Seizure Prediction From Eeg Using Continual Learning With Cnns, Adnan Amin, Ammar Bathich, Feras Al-Obeidat, Safa Naes, Maria Jose Sousa May 2026

Epileptic Seizure Prediction From Eeg Using Continual Learning With Cnns, Adnan Amin, Ammar Bathich, Feras Al-Obeidat, Safa Naes, Maria Jose Sousa

All Works

Epilepsy is a persistent neurological disorder that affects over 50 million people worldwide, with nearly one-third of patients remaining unresponsive to conventional therapeutic treatments. This study introduces a progressively adaptive seizure prediction framework designed to enhance early detection and clinical decision-making. The proposed model employs a deep learning strategy grounded in continual learning (CL) principles, using Convolutional Neural Networks (CNNs) in combination with knowledge distillation techniques. This enables the model to assimilate new data while retaining previously learned information. The approach was evaluated on the publicly available Bonn University EEG dataset, following a sequential learning process in which each successive …


Biogeochemical Mechanisms Behind Water Quality Evolution And Valuable Element Reutilization Of Abandoned Mine Drainage: A Review, Wu Pan, Huang Jiangxun, Li Qingguang, Zhang Ruixue, Li Bo May 2026

Biogeochemical Mechanisms Behind Water Quality Evolution And Valuable Element Reutilization Of Abandoned Mine Drainage: A Review, Wu Pan, Huang Jiangxun, Li Qingguang, Zhang Ruixue, Li Bo

Coal Geology & Exploration

Background Abandoned mine drainage, also known as acidic mine drainage (AMD), represents a major pollution source in mining areas while also serving as an important carrier of strategic critical metals and underground space utilization. In China, water pollution stemming from coal mining is more severe in the south than in the north. This spatial pattern is jointly shaped by climatic conditions, geological settings, and mining history. Advances From the perspective of the environmental geochemical frontier, this study presents a systematic review of AMD formation and evolution mechanisms, as well as technologies for water pollution prevention and control, resource recovery, and …


A Review Of Full-Lifecycle Management Practices For Blue Mining Centered On Sustainable Development And Resource Efficiency, Hou Zhengmeng, Zhang Shengyou, Chen Qianjun, Sun Wei, Zhang Tian, Cai Nan, Huang Liangchao, Wang Qichen, Shi Tianle, Xu Xiaochuan May 2026

A Review Of Full-Lifecycle Management Practices For Blue Mining Centered On Sustainable Development And Resource Efficiency, Hou Zhengmeng, Zhang Shengyou, Chen Qianjun, Sun Wei, Zhang Tian, Cai Nan, Huang Liangchao, Wang Qichen, Shi Tianle, Xu Xiaochuan

Coal Geology & Exploration

Against the backdrop of China’s goals of peak carbon dioxide emissions and carbon neutrality, along with the growing demand for critical minerals, this study presents a systematic review of domestic and international literature and engineering cases. Based on the Blue Mining concept proposed by Langefeld’s team of the Clausthal University of Technology and from the perspective of planning forward, this study organizes key technologies, treatment pathways, and essentials of full-lifecycle management used to transition mines from single-purpose stopes to multifunctional infrastructures. Centered on four guiding principles, i.e., energy, ergonomics, water resources, and circularity, this study reviews the synergetic planning process …


Phytochemical Composition And Bioactivities Of Roselle (Hibiscus Sabdariffa L.) Extracts Obtained By Infusion, Ethanolic Maceration, And Maltodextrin-Assisted Drying, Risna Silvianti, Warsito Warsito, Elok Zubaidah, Zubaidah Ningsih, Aqidatul Izza May 2026

Phytochemical Composition And Bioactivities Of Roselle (Hibiscus Sabdariffa L.) Extracts Obtained By Infusion, Ethanolic Maceration, And Maltodextrin-Assisted Drying, Risna Silvianti, Warsito Warsito, Elok Zubaidah, Zubaidah Ningsih, Aqidatul Izza

Karbala International Journal of Modern Science

Roselle (Hibiscus sabdariffa L.) is rich in phenolic compounds and anthocyanins, but the extraction method may influence its chemical composition and biological activity. This study compared hot-water infusion, ethanolic maceration, and maltodextrin-assisted drying. It aimed to examine the relationship between the extraction method, chemical profile, and bioactivity. The resulting extracts (EI, EM, and EP) were analyzed for total phenolic, flavonoid, and anthocyanin, LC-HRMS profiles, and antioxidant capacity by the FRAP assay. Antibacterial analysis was conducted against Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923) using agar well diffusion. Cytotoxicity tests (MTT, 24 h) were performed against HT-29, 4T1, …


Effects Of Warming On Growth And Leaf Colonization By Litter Mat-Forming Fungi In A Wet Tropical Forest In Puerto Rico, Ari E. Puentes, D. Jean Lodge, Deyaneira A. Ortiz-Iglesias, Tatiana Barreto-Vélez, Laura C. Rubio-Lebrón, Hieu Chu, Christine S. O'Connell, Sasha C. Reed, Tana E. Wood May 2026

Effects Of Warming On Growth And Leaf Colonization By Litter Mat-Forming Fungi In A Wet Tropical Forest In Puerto Rico, Ari E. Puentes, D. Jean Lodge, Deyaneira A. Ortiz-Iglesias, Tatiana Barreto-Vélez, Laura C. Rubio-Lebrón, Hieu Chu, Christine S. O'Connell, Sasha C. Reed, Tana E. Wood

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Wet tropical forests are experiencing rising temperatures and increased frequency and intensity of extreme climatic events, such as cyclones, which can increase rates of soil erosion and surface runoff. Fungal litter mats, formed by agaric decomposer fungi, play a crucial role in stabilizing slopes, preventing erosion, and aiding nutrient cycling; however, little is known about how warming affects litter mat growth and function. We investigated two litter mat-forming fungi, Gymnopus johnstonii and Marasmius aff. crinis-equi, in warmed (+4°C above ambient) and control plots in the Luquillo Experimental Forest, Puerto Rico. Growth and time-to-leaf colonization were monitored over 6 weeks …


How Fe(Ii)/2-Oxoglutarate Oxygenase Chooses Chlorination Over Hydroxylation: Electric Field-Driven Ligand Exchange Governs C-Cl Formation, Simahudeen Bathir Jaber Sathik Rifayee, Midhun George Thomas, Anandhu Krishnan, Kritika Gupta, Carter Davis, Tatyana Karabencheva-Christova, Christo Z. Christov May 2026

How Fe(Ii)/2-Oxoglutarate Oxygenase Chooses Chlorination Over Hydroxylation: Electric Field-Driven Ligand Exchange Governs C-Cl Formation, Simahudeen Bathir Jaber Sathik Rifayee, Midhun George Thomas, Anandhu Krishnan, Kritika Gupta, Carter Davis, Tatyana Karabencheva-Christova, Christo Z. Christov

Michigan Tech Publications

Non-heme Fe(II)/2-oxoglutarate (2OG)-dependent halogenases catalyze highly selective C-H halogenation. BesD is a non-heme Fe(II)/2OG halogenase that performs regio- and stereoselective chlorination of the l-lysine (l-Lys) substrate. Understanding the mechanism by which halogenation is favored over canonical hydroxylation is essential for guiding enzyme engineering efforts aimed at converting hydroxylases into halogenases. Here, we combine molecular dynamics (MD) and hybrid quantum mechanics/molecular mechanics (QM/MM) calculations to elucidate the origin of chlorination selectivity in BesD and variants derived from a homologous hydroxylase. Our results indicate that, although the initial inline Cl-Fe(III)-OH intermediate is inherently predisposed toward hydroxylation, it undergoes a two-step isomerization in …


Lowland Tropical Forests Remain A Methane Sink Under Warming And Long-Term Hurricane Disturbance Recovery, Gabriele Larocca Conte, Lucia Zuvela, Rachel Cruz-Pérez, Tatiana Barreto-Vélez, Nibia Becerra-Santillan, Sophia F. Campbell, Hieu P. Chu, Trung Dam, Iana F. Grullón-Penkova, Miriam Kleit, Deyaneira A. Ortiz-Iglesias, Laura C. Rubio-Lebrón, Molly A. Cavaleri, Sasha C. Reed, Debjani Sihi, Tana E. Wood, Christine S. O'Connell May 2026

Lowland Tropical Forests Remain A Methane Sink Under Warming And Long-Term Hurricane Disturbance Recovery, Gabriele Larocca Conte, Lucia Zuvela, Rachel Cruz-Pérez, Tatiana Barreto-Vélez, Nibia Becerra-Santillan, Sophia F. Campbell, Hieu P. Chu, Trung Dam, Iana F. Grullón-Penkova, Miriam Kleit, Deyaneira A. Ortiz-Iglesias, Laura C. Rubio-Lebrón, Molly A. Cavaleri, Sasha C. Reed, Debjani Sihi, Tana E. Wood, Christine S. O'Connell

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Methane (CH4) is a potent greenhouse gas, and tropical forests account for roughly one–third of global atmospheric CH4 uptake by soils. Projected warming and more frequent hurricanes in these ecosystems may alter soil CH4 sink strength, as warmer and wetter soils enhance methanogenesis activity. We measured soil CH4 and CO2 efflux during the calendar summer months of 2023 and 2024 alongside continuous records of soil moisture, soil and air temperature, and precipitation in an in–situ warming experiment (TRACE) located in a lowland tropical forest in Puerto Rico, six to seven years after Hurricanes Irma …


Photocatalytic Advanced Oxidative Processes (Aop) As A Promising Agricultural Runoff Treatment Solution For The California Central Valley, Briana Miller May 2026

Photocatalytic Advanced Oxidative Processes (Aop) As A Promising Agricultural Runoff Treatment Solution For The California Central Valley, Briana Miller

Master's Projects and Capstones

Pesticide pollution in the California Central Valley (CV) is a major concern for aquatic toxicity. This research will determine if photocatalytic advanced oxidation processes (AOP), an emerging water treatment technology, could be implemented within the CV to degrade pesticides. A case study, literature review, comparative analysis, and policy analysis were conducted to identify pesticides of concern within the CV, if photocatalytic AOP can degrade those pesticides, how photocatalytic AOP compares to current technologies, and regulatory challenges with implementing photocatalytic AOP. Between 2019 and 2023, the top 30 most applied pesticides were identified, with 12 chemicals identified as aquatic toxicants, seven …


Climate-Driven Maritime Hazards And Marine Fuel Oil Spill Risk In The Northwest Passage, Emily Grace Parker May 2026

Climate-Driven Maritime Hazards And Marine Fuel Oil Spill Risk In The Northwest Passage, Emily Grace Parker

Master's Projects and Capstones

Shipping activity across the Northwest Passage has increased by 46% since 2011 as climate forcing drives sea ice decline, but associated risks to vessels and the environment are underestimated and rarely examined together. A literature review conducted in this study indicated that by 2070, a 5-month navigation window will expose vessels to increasingly unpredictable hazards as the region transforms from an ice- to wave-dominated regime, with wave heights increasing by 10-13% per decade. Ice hazards persist, and vessels operating in early summer and late fall will be exposed to elevated ice accretion risk that can cause capsizing and marine fuel …


The Role Of Intermittent Nutrient Loading In The San Francisco Bay, Rebecca M. To May 2026

The Role Of Intermittent Nutrient Loading In The San Francisco Bay, Rebecca M. To

Master's Projects and Capstones

A harmful algal bloom in 2022 shattered the illusion that the highly enriched San Francisco Bay is resilient to eutrophication. This event provided justification for the San Francisco Water Board to issue restrictions on nitrogen in wastewater effluent, the largest source of nitrogen in San Francisco Bay. Recognizing San Francisco’s fragile status even with this recent regulation, this study analyzes other anthropogenic sources of nutrient pollution, and it examines nature-based solutions to drawdown nutrient loading. This research utilizes a nutrient budget review to account for nitrogen inputs, a relative source contribution to quantify sanitary sewer overflows, a geospatial analysis to …


Linking Fishery Productivity To Child Health In The Coastal Tropics, Francisco Flores-Mejia May 2026

Linking Fishery Productivity To Child Health In The Coastal Tropics, Francisco Flores-Mejia

Master's Theses

Fish are a primary source of calories, macronutrients, and income for coastal communities around the world, but overfishing and environmental changes have dramatically reduced productivity in the majority of small-scale fisheries. The social costs of these losses are believed to be large, particularly in poorer communities, but most estimates of fishery productivity effects on households are contextual and difficult to generalize. We combine a remote sensing measure of pelagic fishery productivity with geolocated child health and growth data from 34 countries in the coastal tropics. We estimate that the difference between sustainedly good versus bad fishing conditions corresponds up to …


Computational-Experimental Synergy As A Predictive And Interpretive Tool Through Metal-Organic Framework Investigations, Cristian Sayers May 2026

Computational-Experimental Synergy As A Predictive And Interpretive Tool Through Metal-Organic Framework Investigations, Cristian Sayers

Graduate Student Theses and Dissertations

In the search for tunable materials platforms capable of addressing both clean energy conversion and viable post-combustion carbon capture, metal-organic frameworks (MOFs) have emerged as a uniquely versatile class of porous solids offering high specific surface area, structural tunability, and chemically addressable metal nodes and organic linkers. Realizing their potential requires understanding behavior that spans atomic-scale electronic structure and bulk-scale property response, a regime in which neither computation nor experiment alone is sufficient. This work attempts to develop a tighter integration between density functional theory (DFT) and laboratory investigation, treating the two modalities as mutually informing probes of the same …


Productive Armature, Gabriel Ofem Peter May 2026

Productive Armature, Gabriel Ofem Peter

Masters Theses

What if water was all you had, what if your only source of survival was a body of water? I shudder to think that some people get to be put in this situation in the world we live in. As I understand the importance of water to survival, it is obvious that water can be the only lifeline of survival for a community. This is the experience for residents of Makoko, Lagos. Their survival depends on the Lagos Lagoon, a large body of water flowing in from the Atlantic Ocean. This research looks beyond the surface of what this community …


Frictional Intelligence, Posheng Cheng May 2026

Frictional Intelligence, Posheng Cheng

Masters Theses

This is an experimental interaction design project that challenges anthropomorphism in human-computer interaction. In particular, the recent advancement of artificial intelligence technologies like Large Language Models has taken anthropomorphism to new heights. The conversational chatbot interface of AI prioritizes mimicking an inherently human communication medium to maximize human-likeness. However, anthropomorphism has several downsides. Conversational interfaces obscure the limitations and the tangible cost of the technology. They also imply fictional moral status and human-level cognitive capabilities, which means general public sentiment focuses on the ``overhyped'' excitement and fear rather than on other socio-ethical and capacity questions that are far more urgent …


Somatic Prosthetics For Planetary Resonance, Disha Dharesh Kumar R May 2026

Somatic Prosthetics For Planetary Resonance, Disha Dharesh Kumar R

Masters Theses

This thesis investigates how industrial design can transcend extractive technological paradigms in favor of relational interfaces that foster planetary attunement. Framing the climate crisis as a 'crisis of imagination', the research challenges the Western bifurcation of nature and culture by drawing on Indic cosmologies- which recognize stones, plants, and ecosystems as conscious at different levels and participants in a shared cosmic field. By synthesizing research in Biosemiotics, Quantum Information Pansycishm, and Neuroscience, the project redefines intelligence as a distributed, more-than-human phenomenon.

The research materializes as a speculative design artifact: a device that functions as a somatic prosthetic for planetary resonance. …


Characterizing Stiffness Dynamics Of Normal And Malignant Breast Spheroids Using Brillouin Microscopy, Razanne Rafat Zaghloul, Karlin Hilai, Chenjun Shi, Jitao Zhang May 2026

Characterizing Stiffness Dynamics Of Normal And Malignant Breast Spheroids Using Brillouin Microscopy, Razanne Rafat Zaghloul, Karlin Hilai, Chenjun Shi, Jitao Zhang

Medical Student Research Symposium

Background: Breast cancer progression and metastasis are closely linked to alterations in the mechanical properties of tumor cells and their microenvironment. Softer, more deformable cells are often associated with higher metastatic potential. While atomic force microscopy (AFM) is the current gold standard for mechanical characterization, it is limited to surface measurements and can damage 3D cultures. It remains unclear how the mechanical properties evolve over time in normal versus malignant spheroids. This study utilizes Brillouin light-scattering microscopy, a non-contact and label-free optical technique, to assess stiffness changes in normal and malignant breast epithelial spheroids over time. Understanding these mechanical signatures …


Beyond Stabilization: Biological Healing, Structural Exclusion, And The Recovery Gap After Border-Fall Trauma At The U.S.-Mexico Border, Julia Robinson May 2026

Beyond Stabilization: Biological Healing, Structural Exclusion, And The Recovery Gap After Border-Fall Trauma At The U.S.-Mexico Border, Julia Robinson

Undergraduate Honors Theses

This honors thesis examines the biochemical, ethical, and public health consequences of insufficient post-operative follow-up care for undocumented immigrants injured in border falls. Discussing pathways of inflammation resolution, wound healing, and bone remodeling, this thesis argues that recovery depends on tightly regulated molecular and cellular processes that are highly vulnerable to disruption without continued monitoring and rehabilitation (Loi et al., 2016; Maruyama et al., 2020). When follow-up care is absent, these processes can be predicted to derail, leading to infection, impaired healing, and permanent disability (Chung & Sohn, 2025; Howard et al., 2020; Kruidenier et al., 2018). Framed through principles …


Dialogue Between Mind And Algorithm: Deep Symbiosis Of Psychology And Artificial Intelligence, Xiaolan Fu, Zheng Yan May 2026

Dialogue Between Mind And Algorithm: Deep Symbiosis Of Psychology And Artificial Intelligence, Xiaolan Fu, Zheng Yan

Bulletin of Chinese Academy of Sciences (Chinese Version)

As artificial intelligence (AI) evolves from a supportive tool into a collaborative partner, the convergence of psychology and AI is gradually shifting from one-way application toward deep symbiosis. This study discusses the mutual empowerment resulting from their interaction, as well as the challenges they face and potential pathways to breakthroughs. On the one hand, psychology empowers AI by enhancing its human-like intelligence and social adaptability through cognitive modeling and ethical constraints; on the other hand, AI empowers psychology by leveraging multimodal data and algorithmic models to revolutionize psychological assessment and intervention methods. This deep symbiosis requires a clear-eyed acknowledgment of …


Arylation Of Nitrogen, Oxygen And Carbon Nucleophiles By Aryl(Tmp)Iodonium Salts, Joseph Jordan Hatton May 2026

Arylation Of Nitrogen, Oxygen And Carbon Nucleophiles By Aryl(Tmp)Iodonium Salts, Joseph Jordan Hatton

Dissertations and Theses

Substituted aromatic rings are present in industry in a plethora of organic molecules such as pharmaceuticals, agrochemicals, materials and beyond. Therefore, methods for broadly installing aryl rings into other compounds to create substituted aromatic rings are valuable to many organic chemists. Historically these transformations are achieved through methods such as nucleophilic aromatic substitution and metal catalyzed cross-coupling. Nucleophilic aromatic substitution is a user-friendly method in this space but is limited by reliance on specific electronics. Metal catalyzed cross-coupling reduced the dependence on electronics in this space, but metals are generally unattractive reagents due to high costs, toxicity and challenges with …


Isolation Of Essential Oils From Oregano Leaves Via Steam Distillation And Extraction, Alyssa Brasko, Madison Fauntleroy, Sophia Bordone May 2026

Isolation Of Essential Oils From Oregano Leaves Via Steam Distillation And Extraction, Alyssa Brasko, Madison Fauntleroy, Sophia Bordone

Discovery Day - Daytona Beach

Organum vulgare, also known as Oregano, is a fragrant herb in the mint family widely used in culinary and medical applications. The essential oil of oregano contains various compounds, with carvacrol and thymol being the primary constituents responsible for the herb’s distinctive aroma and antimicrobial properties. Carvacrol, a chemical compound found in oregano oils, has a molecular formula of C10H14O, with carvacrol presenting a phenolic structure that contributes to its biological activity. Additionally, the compound has three double bonds giving the compound four units of unsaturation. Due to its properties, oregano oil has historically been used …