Digital Commons Network^™

Technological Development Of In-Cell Nmr: Microfluidic, Metabolomic, And Fluxomic Approaches, Nicholas Sciolino

Electronic Theses & Dissertations (2024 - present)

In the fields of structural biology, metabolomics, and fluxomics, there is a driving, technique-based concern when it comes to high-resolution spectrometry and its marriage to biological and physiological relevance. Sample preparation often involves cellular perturbation, lysate separation schemes, combinations with non-biological reagents, and timeline slack. Conceptually, the farther we get from the cell, the greater the potential disparity between what exists in vivo and our in vitro manipulations. This is particularly true when seeking to collect data on transfected targets of interest, and on sensitive metabolic equilibria that occur on the order of minutes. The question remains: if we are …

Enhancing Alfalfa Persistence In Rangelands: Evaluating Morphological Traits Of Medicago Sativa Subsp. Falcata Germplasm, Abdulallah Mohammed Alomair

Electronic Theses and Dissertations

Rangelands cover nearly half of the Earth’s surface, representing about 54% (79 million km2), and occur in different types and climates worldwide. Alfalfa (Medicago sativa L.) is a major component in rangelands and covers about (320 thousand km2), representing about 0.4% of total global rangeland area. As a critical perennial legume crop, alfalfa can improve soil health by fixing approximately 336 kg/ha/year of nitrogen and sequestering up to 614 kg/ha/year of carbon, while enhancing livestock production due to its high content level of vitamins, magnesium, minerals, fiber, and protein. However, environmental stresses such as drought, freezing, and grazing limit alfalfa …

Key Brain Region Identification In Obesity Prediction With Structural Mri And Probabilistic Uncertainty Aware Model, Walia Farzana, Megan A. Witherow, Ahmed Temtam, Liangsuo Ma, Melanie Bean, F. Gerry Moeller, K. M. Iftekharuddin

Electrical & Computer Engineering Faculty Publications

Objectives/Goals: Predictive performance alone may not determine a model’s clinical utility. Neurobiological changes in obesity alter brain structures, but traditional voxel-based morphometry is limited to group-level analysis. We propose a probabilistic model with uncertainty heatmaps to improve interpretability and personalized prediction. Methods/Study Population: The data for this study are sourced from the Human Connectome Project (HCP), with approval from the Washington University in St. Louis Institutional Review Board. We preprocessed raw T1-weighted structural MRI scans from 525 patients using an automated pipeline. The dataset is divided into training (357 cases), calibration (63 cases), and testing (105 cases). Our probabilistic model …

Role Of C4 Resources In Isotopic Variability In Diet Among Children From Kellis 2 Cemetery, Dakhleh Oasis, Egypt, Faith R. Hendrix

Honors Undergraduate Theses

Using stable carbon isotope analysis, this study investigates dietary diversity in children buried at the Kellis 2 Cemetery (c. AD 50–450) in Egypt's Dakhleh Oasis. From the analysis of δ¹³C isotope values in hair keratin and bone collagen, the study reconstructs short-term and long-term dietary signals in juvenile and adult subjects. The aim is to clarify the role of C₄ plants—particularly millet—in weaning and childhood diets in a Romano-Christian Egyptian village context. A total of 631 segmented hair and 54 bone collagen samples were analyzed from 127 juveniles and 97 adults. Juvenile individuals (i.e., under 15 years biological age) showed …

Integrated Pest Management: State Infrastructure Status After 50 Yr Of Federal Support (1973 To 2023), Daren S. Mueller, Laura C. Iles, Carol L. Pilcher, Adam J. Sisson, Roger Magarey, Ryan Adams, Wanda I. Almodovar, Diane Alston, Patrick Beauzay, Ricardo Bessin, Mandy Bish, Mary Burrows, Alejandro Calixto, Rakesh Chandran, Jed B. Colquhoun, Mary Concklin, Amy J. Dreves, Peter C. Ellsworth, Paul D. Esker, James J. Farrar, Alfred Fournier, Daniel Frank, Kelly Hamby, George Hamilton, Anthony Hanson, Ann Hazelrigg, Natalie Hein-Ferris, David Held, James Jasinski, Heather M. Kelly, David Kerns, Miranda Kersten, Lauren Kerzicnik, Janet Knodel, Glen Koehler, Heidi Kratsch, Christian H. Krupke, Norman C. Leppla, Erin Lizotte, Casey Matney, Rebecca A. Melanson, Frannie Miller, Marion Murray, David Owens, Diane Plewa, Francis P. F. Reay-Jones, Silvia I. Rondon, Tom A. Royer, Philip A. Rozeboom, Hilary A. Sandler, Scott P. Schell, Marissa Schuh, Timothy Seipel, Danesha Seth Carley, Ashfaq Sial, Raghuwinder Singh, Damon L. Smith, Tim Stock, Glenn Studebaker, Adrianna Szczepaniec, Lisa Tewksbury, John Tooker, Adam J. Varenhorst, Amber Vinchesi-Vahl, Doug Walsh, Desiree Wickwar, Robert J, Wright, Simon Zebelo

Department of Entomology: Faculty Publications

Integrated pest management uses a variety of tools coupled with historical, current, and projected information for economical pest protection of crops and other resources while accounting for risk to humans and the environment. Following the 1972 US Federal IPM Policy, funding for integrated pest management programming has continued for 50+ years. However, multifaceted changes during this time have significantly affected state-level integrated pest management infrastructure, prompting a comprehensive survey to assess conditions, limitations, and growth potential of US integrated pest management programs. A survey was sent to 50 US states and 3 territories with integrated pest management programs in November …

Congestion Mitigation For Foraging Robot Swarms Using Spiral Path Strategies, Arturo Gonzalez, Qi Lu

Computer Science Faculty Publications

Swarm robotics offers robust and scalable solutions for tasks such as foraging, but congestion near central collection zones remains a critical challenge, especially with increasing swarm sizes. Traditional solutions, such as static path planning or local repulsion-based methods, often fail to prevent interrobot collisions or bottlenecks near the collection zones. This research presents a comparative study of three strategies to mitigate congestion when returning resources to the central collection zone. The research herein focuses on tightly packed environments where, in theory, robots should follow a preplanned spiral, either ad-hoc, square, or circular, with congestion detection as described in the first …

Heterotrophy Of Particulate Organic Matter Subsidies Contributes To Divergent Bleaching Responses In Tropical Sclaractinian Corals, Connor R. Love, Kelly E. Speare, Michael D. Fox, Veronica Z. Radice, Kelton W. Mcmahon, Gretchen E. Hofmann,, David L. Valentine, Marie E. Strader

Biological Sciences Faculty Publications

Heterotrophic feeding on plankton and particulate organic matter (POM) by tropical Scleractinian corals is known to aid in the resistance and recovery from thermally induced bleaching. However, the relative importance of heterotrophy in promoting bleaching resistance and recovery is likely to vary based on ecological context and the severity of heat stress. In 2019, the Pacific Island of Mo'orea experienced mass coral mortality during a widespread marine heatwave. Many Acropora hyacinthus colonies on the shallow reef slope (5 m) were resistant to bleaching, while colonies on the deeper fore reef (14 m) often bleached and subsequently recovered, despite similar thermal …

Diel Variations In Abundance Of Viral, Picoplankton, And Nanoplankton In Coastal Waters Of Taiwan In Spring, Patrichka Wei-Yi Chen, Madeline Olivia, Vladimir Mukhanov, Ufimtseva Margarita, Liashko Tatiana, Sakhon Evgenii, Supriyadi Supriyadi, Intan Dwi Puspitasari, Arpita Ghosh, An-Yi Tsai

Journal of Marine Science and Technology–Taiwan

The diel variations of viruses (< 0.2 μm), picoplankton (0.2-2 μm; heterotrophic bacteria, Synechococcus spp., and picoeukaryotes), and nanoflagellates (2-20 μm; heterotrophic and pigmented nanoflagellates) were examined for 2 days with approximately 4 h of temporal sampling in the spring of 2024 in coastal surface waters of the subtropical western Pacific. The abundance of bacteria did not follow a consistent diel pattern, and viral abundance was positively correlated with bacterial abundance. Synechococcus spp. was found to grow during the light period and with peak abundance at night, exhibiting a remarkably diel pattern; however, the pattern was opposite in picoeukaryotes. In the size-fractionation experiments, after 32 h of …

Food Rescue, Food Waste, And Policy In New York: A Mixed-Methods Study Of Food System Impacts, Mariana Torres Arroyo

Electronic Theses & Dissertations (2024 - present)

This dissertation investigates how food donation policies in New York State influence the recovery, redistribution, and waste of surplus fresh produce, with a focus on fruits and vegetables. Using an interdisciplinary, systems-based approach that integrates system dynamics modeling with qualitative, community-engaged research, the study analyzes the effectiveness and unintended consequences of three major policies: Nourish New York, the Farm to Food Bank tax credit, and the Food Donation and Food Scraps Recycling Law.

Chapter 2 uses simulation modeling to examine how the tax credit and waste ban affect produce recovery and redistribution. Results show that while both policies can boost …

Food Insecurity Among Graduate Students At The University Of Alabama At Birmingham, Amy Elizabeth Callahan

All ETDs from UAB

College food insecurity (FI) has grown steadily as a field of research over the past fifteen years. Existing research primarily has demonstrated that FI is a persistent problem with various risk factors and myriad potential impacts on students, though graduate students are largely understudied in favor of undergraduate and aggregated student populations. Given the unique circumstances graduate students face, as well as expected demographic differences such as age and household characteristics, this is a serious gap in the literature. This dissertation aims to investigate graduate student food insecurity in the United States, and particularly at the University of Alabama at …

Analysis Of Gas Station Drugs Using Gas Chromatography Mass Spectrometry And Fourier Transform Infrared Spectroscopy, Megan Joos

All ETDs from UAB

Gas stations and head shops are a seemingly safe and legal marketplace for drug purchase. However, although marketed as dietary supplements or cognitive enhancers, the products sold there have been known to contain psychoactive substances which may be mislabeled or actually contain regulated substances. This study investigates the composition of such products, specifically those labeled as kratom and non-kratom Mitragyna species using gas chromatography-mass spectrometry (GC-MS) and those labeled as phenibut using GC-MS and fourier transform infrared spectroscopy (FTIR). Samples were acquired from retailers in the Birmingham, AL area. The products underwent both qualitative and quantitative analysis of their ingredients …

Substrate Preference And Foraging Behavior Of Two Declining Warblers In Appalachian Shrublands, Samantha Fishman

Theses and Dissertations

Abstract Shrubland and early successional habitats (ESH) support a diversity of wildlife, including many declining songbirds. However, nonnative shrubs increasingly dominate these habitats, potentially altering habitat quality by influencing prey availability. Habitat quality can be assessed by observing foraging behaviors of songbirds and identifying preferred and avoided substrates as well as testing the predictions of optimal foraging theory; specifically that birds will maximize their energy gain relative to the costs. We examined foraging behaviors of Golden-winged Warblers (Vermivora chrysoptera; GWWA) and Chestnut-sided Warblers (Setophaga pensylvanica; CSWA) in ESH on private lands in Virginia with varying amounts …

Using A Water Quality Index To Assess The Impacts Of Heavy Metals Contamination For Sustainable Water Management: A Case Study Of The Bang Pakong River, Thailand, Khin Yadana Soe, Pokchat Chutivisut, Wilailuk Niyommaneerat

Applied Environmental Research

Anthropogenic activities such as improper waste disposal, excessive fertilizer use, and industrial effluents cause heavy metal contamination in water, soil, and the atmosphere. Herein, the water quality index (WQI) was used to characterize heavy metal (i.e., cadmium (Cd), arsenic (As), and mercury (Hg)) contamination in the Bang Pakong River, Thailand. Specifically, water samples were collected during the dry season from four stations along the river from 2012–2022. The heavy metal concentrations in the samples were analyzed via atomic absorption spectrophotometry, and WQI values were calculated on the basis of standard water quality parameters. At the four sampling stations, high As …

Halotolerant Biodegradation And Detoxification Of Synthetic Dyes By Marine-Derived Penicillium Oxalicum M6a: Metabolite Profiling And Ecotoxicity Assessment, Ugochukwu Okechukwu Ozojiofor, Mohammed Sani Abdulsalami, Nkechi Eucharia Egbe, Ahmed Ali Haroun, Yakubu Magaji

Applied Environmental Research

The complex aromatic structures of synthetic dyes in contaminated water bodies make them difficult to degrade, posing a serious environmental challenge and representing a significant emerging pollutant that warrants urgent intervention. This study evaluated the biodegradation and detoxification potential of a halotolerant, marine-derived fungal strain, Penicillium oxalicum M6A, isolated from the Nigerian coastline, against Indigo carmine (IC) and Remazol Brilliant Blue R (RBBR). The effects of pH, temperature, salinity, and dye concentration on degradation efficiency, alongside enzymatic activity, were assessed. FTIR and GC‒MS analyses were employed to identify degradation products and predict metabolic pathways, whereas toxicity was evaluated in three …

Assessment Of Metal Contamination And Potential Health Risk Of Roadside Vegetables Along The Sayre Highway, Province Of Bukidnon, Philippines, John R.N. Labajo, Junesa U. Cristobal, Myrna G. Pabiona

Applied Environmental Research

This study assessed heavy metal contamination in roadside vegetables (Ipomoea batatas and Moringa oleifera) across five urbanized localities in Bukidnon, Philippines, and evaluated potential human health risks. Metal concentrations (Cd, Cr, Cu, Co, Fe, Mn, and Zn) were analyzed via atomic absorption spectro-photometry and compared against FAO/WHO maximum permissible limits. The results revealed severe contamination, with Mn (575.27–862.17 mg kg-1) and Fe (256.46–706.68 mg kg-1) dominating natural soil mineralogy (Adtuyon series) and anthropogenic inputs. Toxic Cr (16.20–21.93 mg kg-1) exceeded permissible limits by nine and a half times in Quezon. Health risk assessments revealed negligible noncarcinogenic risks (THQ …

Spatial Estimation Of Trophic State For Reservoir Using Ground Monitoring And Remote Sensing Data, Thong Nguyen Hoang, Van Tran Thi

Applied Environmental Research

Nutrient pollution, also known as eutrophication, is a severe environmental problem that leads to harmful algal blooms in water bodies and affects water supplies for human use. This study aims to determine the trophic state of the reservoir based on the trophic state index (TSI) calculated from ground monitoring data of Secchi depth (SD), total phosphorus (TP), and chlorophyll-a (Chl-a) obtained from 35 points in 2 survey periods during the late rainy season to early dry season 2012–2013 and May 2023. In addition, we combined remote sensing data to spatially estimate the eutrophication situation across the reservoir through correlation analysis …

Nationwide Household Food Waste Generation Rates In Rural And Urban Settings: Evidence In Thailand, Vilasinee Krutprong, Chanathip Pharino

Applied Environmental Research

To achieve sustainable development goals, addressing food waste requires evidence-based solutions grounded in a nuanced understanding of waste generation rates and the factors influencing them. This study explores the intricate dynamics of food waste generation in Thai households, encompassing both liquid and solid waste streams. Empirical data were collected from 2,700 diverse households across urban and rural areas over a four-week period. The study revealed an average food waste generation rate of 0.332±0.003 kg per capita per day when liquids were included and 0.228± 0.002 kg per capita per day when liquids were excluded. Surprisingly, rural households generated more food …

Effects Of Herbicides On 2,4-D-Resistant Soil Microorganisms In Maize Cultivation In Lopburi Province, Thailand, Boontarik Chimchart, Jitra Kokaew, Amnat Eamvijarn, Kanokon Bunpha, Sontaya Khamtib, Monchai Manassila, Tawatchai Inboonchuay

Applied Environmental Research

This study aimed to assess the impact of herbicide application on soil micro-organism density and to identify microorganisms resistant to 2,4-D-dimethyl-ammonium (2,4-D) for potential biodegradation. Research was conducted in maize plots in Lopburi Province, where 2,4-D was applied at a rate of 120 g of active ingredient per 160 m2. The soil samples were collected at various intervals: before application; 2 and 4 hours postapplication; and 1, 3, and 7 days after application. The analyses included soil property and microorganism population analyses. The results indicated that 2,4-D applications significantly increased bacteria and fungi in the treated plots compared with those …

Investigating Risk Of Suboptimal Hiv Treatment Outcomes (Treatment Failure And Disengagement) Among Pregnant And Postpartum Women Living With Hiv, Kevin Owuor

All ETDs from UAB

The joint United Nations Programme on HIV/AIDS (UNAIDS) has set targets to end the HIV epidemic by improving HIV diagnosis, treatment, and viral suppression to reduce new infections and improve health outcomes for people living with HIV (PLHIV), including pregnant and postpartum women living with HIV (PPWH). After diagnosis, linking PPWH to antiretroviral (ART) treatment is critical to suppress the virus and prevent mother-to-child transmission (MTCT) of HIV. Continuous engagement in care is essential for achieving and maintaining virologic suppression in the peripartum and postpartum period for PPWH, both for their own health and the health of their family. Disengagement …

Predictive Modeling For Healthcare Data Using Nonlinear Bayesian Methods, Prince Kofi Asare

Theses and Dissertations

Unplanned hospital readmissions represent a significant challenge for healthcare systems, contributing to substantial financial burdens and highlighting gaps in patient care coordination. In the U.S., approximately 20% of Medicare beneficiaries are readmitted within 30 days, costing billions annually. Social determinants of health, such as income, housing stability, and social support, account for up to 80% of health outcomes, yet their integration into predictive models remains underexplored. This study introduces a novel Bayesian framework for predicting 30-day readmission risk, combining Gaussian Process models with spike-and-slab priors and Bayesian Lasso regression with Laplace priors. Utilizing Markov Chain Monte Carlo methods, the approach …

Global Strategies To Manage Huanglongbing (Hlb) And Its Vectors: Insights And Implications For The Mediterranean Region, Meritxell Pérez-Hedo, Mark S. Hoddle, Fernando Alferez, Lochy Batista, George A.C. Beattie, Shourish Chakravarty, Paul Holford, Fathiya Mbarak Khamis, Inusa Jacob Ajene, Aruna Manrakhan, Paul H. Fourie, Maritza Luis, Eduardo Osorio-Hernández, Mamoudou Sétamou, Alejandro Tena, Pedro Takao Yamamoto, Tara Wade, Changyong Zhou, Nian Wang, Lukasz L. Stelinski, Alberto Urbaneja

All Peer-Reviewed Publications

Huanglongbing (HLB), also known as citrus greening disease, poses a severe threat to the global citrus industry. This disease is caused by three species of bacteria, ‘Candidatus Liberibacter asiaticus’, ‘C. L. africanus’, and ‘C. L. ameri-canus’. The primary pathogen vectors are the Asian citrus psyllid (Diaphorina citri Kuwayama, Hemiptera: Psyllidae) and the African citrus psyllid (Trioza erytreae Del Guercio, Hemiptera: Triozidae). The disease is incurable, and its management relies on reducing vector densities and the adverse effects of bacterial infections on host trees. Managing psyllid vec-tors, especially D. citri, has proven exceptionally challenging due to its rapid spread and subsequent …

Group And State-Specific Estimation In Animal Movement Models Using A Bayesian Approach, Anita Bhandari Sharma

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This research study investigates statistical approaches for modeling the movement patterns of white-tailed deer in Louisiana using GPS tracking data. We start by classifying the latent behavioral states using a hidden Markov model (HMM) and then integrate those inferred states into a state-dependent step selection framework to evaluate the land cover preferences. Standard HMMs, however, assume the same movement patterns for all animals, overlooking the differences due to characteristics such as sex, age, breeding season, etc.

To address this limitation, we extend the modeling framework to incorporate the group-level structure defined by similar characteristics or conditions to assess whether such …

Contribution Of Different Frass Fertilizer Products On Enhanced Growth, Yield And Nutrient Quality Of Broccoli [Brassica Oleracea], Noella Kagehi, Dennis Beesigamukama, Chrysantus M. Tanga, Mathew P. Ngugi, Sevgan Subramanian, Fathiya M. Khamis

All Peer-Reviewed Publications

Vegetables are crucial for food security and income, but in developing countries their production is hindered by low soil fertility. Although the insect frass fertilizer is a potential solution, its use is constrained by limited product choices. Unlike conventional fertilizers, which are available in different forms, the insect frass fertilizer is mostly available in solid form. Here, we evaluated the effects of different black soldier fly frass fertilizer (BSFFF) products on broccoli [Brassica oleracea] growth, yield, and nutritional profiles. Solid, liquid BSFFF, chitin-fortified solid BSFFF, chitin-fortified liquid BSFFF, and commercial organic fertilizer (Safi) were applied at rates equivalent to 250 …

Annual Diversity Of Honey Bee Pollen Sources In Two Pumpkin Growing Landscapes, Machakos County, Kenya, Marystella W. Nang’Oni, Muo Kasina, Rebecca Karanja, Mary M. Guantai, Rahab N. Kinyanjui, Evanson R. Omuse, Michael H.G. Lattorff, Elfatih M. Abdel-Rahman, Marian Adan, Samira A. Mohamed, Thomas Dubois

All Peer-Reviewed Publications

Multi-floral foraging sources for honey bee (Apis mellifera L.) have been threatened by landscape changes and unsustainable farming practices. In East Africa, the biodiversity of forage resources that could support honey bees, especially in agricultural lands, remains least explored. This study investigated pollen diversity for honey bees in Yatta and Masinga Sub-counties in Machakos County, Kenya. Honey bee hives were installed on eight pumpkin (Cucurbita maxima Duchesne ex Lam) farms (one hive per farm) in two varying landscape vegetation classes (low and medium) based on normalized difference vegetation index (NDVI). Pollen traps were installed at the hive entrance and pollen …

Manure Handling In Circular Farming: An In Vitro Study Of Fermented Poultry Manure As Unconventional Feed For Ruminants, Dimas Hand Vidya Paradhipta, De Lavida Padma Terrakota, Ali Agus, Andriyani Astuti, Viagian Pastawan, Kharisma Taufiqa Hidayah

ASEAN Journal on Science and Technology for Development

The development of the poultry industry must consider the principle of circular economy. Therefore, this study aims to develop a method of fermenting poultry manure as a new, unconventional feed, which can support the model of circular farming. Poultry manure obtained from laying hens was mixed with cassava solid waste at a ratio of 7:3 to maintain proper moisture content. The mixed manure fermented for 14 days into a 30 kg silo in triplicate using different additives, namely Lactiplantibacillus plantarum FNCC 0020 at 1 x 10⁵ cfu/g (LP), Bacillus cereus LS2B as proteolytic bacteria at 1 x …

In The Footsteps Of Moose: Using Non-Invasive Techniques To Identify Cause-Specific Calf Mortalities And Evaluate Moose (Alces Alces) Movements Pertaining To Mineral Lick Locations On Ancestral Lands Of The Grand Portage Ojibwe, Anna B. Weesies

Electronic Theses and Dissertations

Following a sharp moose (Alces alces; mooz, Anishinaabemowin, Ojibwe language) population decline in northeastern Minnesota during the early 2000s, the Grand Portage Band of Lake Superior Chippewa initiated a long-term moose collaring effort to assess survival and mortality causes. Moose are a culturally important species to the Band, with annual subsistence hunts held on the Reservation and adjacent 1854 Ceded Territory. Continued research guides culturally appropriate management decisions aimed at bolstering calf and adult survival, helping to preserve this moose in Minnesota today and for subsequent generations. Chapter 1 identifies cause-specific calf mortality rates in this multi-predator system using minimally …

Natural Capital Credit Risk Assessment In Agricultural Lending: An Approach Based On The Natural Capital Protocol, Francisco Ascui, Theodor Florian Cojoianu

Research Collection College of Integrative Studies

It is increasingly recognised that financial institutions have significant impacts and dependencies on natural capital – defined as the stock of the world’s renewable and non-renewable natural resources and ecosystems that yield flows of environmental goods and services, which directly and indirectly underpin the global economy and human wellbeing. Historically, many of these impacts and dependencies have been overlooked. The value of goods and services that nature provides ‘for free’ has often been ignored, and resources have typically been priced at their cost of extraction, rather than the cost of their replacement or substitution, which would promote more sustainable long-term …

Artificial Intelligence In Cancer-Related Malnutrition And Cachexia: A Transformative Tool In Clinical Nutrition, Salvatore Carbone

EVMS School of Health Professions Faculty Publications

[Introduction] Malnutrition and cachexia are common complications in cancer patients, and they negatively influence prognosis, treatment efficacy, and tolerability as well as quality of life [[1], [2], [3]]. Accurately identifying and effectively managing malnutrition and cachexia in this population remains a clinical challenge. Conventional validated screening tools may lack the sensitivity and specificity required for early detection and personalized intervention in diverse cancer types and treatment settings [4,5]. Over the last decade, the use of artificial intelligence (AI), including machine learning (ML) and deep learning (DL) strategies, has shown promising results in clinical nutrition, with the potential to revolutionize nutritional …

Quantifying Links Between Phytoplankton Physiology And The Environment, Gabrielle M. Armin

Open Access Dissertations

Phytoplankton are microscopic, primary producers in aquatic ecosystems worldwide. They are key links in global biogeochemical cycles, converting inorganic compounds into bioavailable nutrients which fuel fisheries. Through photosynthesis, phytoplankton play an essential role in the carbon cycle and marine biological pump, drawing carbon from the atmosphere, which is eventually sequestered in the oceans, regulating our Earth’s climate. Due to their influential role in large scale processes, there have been many efforts to characterize and quantify phytoplankton impacts to ecosystem health and global nutrient cycles. Often, phytoplankton physiology has been highly simplified in global or ecosystem models, limiting their representation to …

Quantifying Mixotrophy Potential As A Function Of Environmental And Biological Drivers In Coastal And Estuarine Plankton Communities, Erica Ewton

Open Access Dissertations

The discovery of mixotrophic plankton has bridged gaps in nutrient cycling budgets and altered the understanding of food webs and energy transfer. Mixotrophic plankton are capable of simultaneous or sequential photosynthesis and heterotrophy, providing multiple avenues of nutrition and thus reducing limitations that affect specialists. These energy dense cells provide increased biomass for higher trophic levels, which may increase organism sizes throughout the food web. Additionally, they may be physically denser, which alters biogeochemical cycling including carbon sequestration. The work presented here uses LysoTracker Green, an acidotropic stain that attaches to phagocytic vacuoles within potentially phagotrophic small (< 20 µm diameter) phytoplankton communities (‘mixoplankton’), to better understand their abundance, relative abundance, and growth rates in relation to the matrix of natural conditions they inhabit. Understanding the prevalence and drivers of mixoplankton is vital to better parameterize biogeochemical cycling and energy transfer in the ocean and for models that predict the fate of future oceans.In the first study, I compared the abundance of mixoplankton in the Northeast U.S. Shelf (NES) and Coastal California Current System (CCS) during two cruises in the NES in summer 2021 and one cruise in the CCS in summer 2022. These two contrasting coastal systems span the breadth of environmental conditions observed in temperate marine ecosystems and thus provided an opportunity to examine indicators of mixoplankton across temperate coastal regions. I discovered higher mixoplankton abundance in the NES than CCS yet similar population sizes of nanoeukaryotic photosynthesizers, resulting in higher relative abundance of mixoplankton in the NES than CCS. Across both systems, I found increased mixoplankton abundance associated with decreasing temperature and combined nitrate + nitrite concentrations (N+N), and increasing light intensity and Synechococcus abundance …