Life Sciences Commons^™

A Hedonic Analysis Of Farm Tractor Auction Prices, Madison Pearson, Chad Fiechter, Andy Campbell

Department of Agricultural Economics Faculty Publications

Used farm machinery values play a critical role in farm management and in assessing the financial health of the agricultural sector. However, the heterogeneity of machines, particularly regarding embedded technology and usage, complicates efforts to isolate the factors that influence prices. This study leverages a detailed dataset from Tractor Zoom to estimate the effects of machine characteristics and market conditions on auction prices of used 300 to 450 horsepower tractors. We find a nonlinear relationship between machine usage and price: tractors with fewer than 500 hours of use lose approximately 118⁢𝑝⁢𝑒⁢𝑟⁢𝑎⁢𝑑⁢𝑑⁢𝑖⁢𝑡⁢𝑖⁢𝑜⁢𝑛⁢𝑎⁢𝑙⁢ℎ⁡𝑜⁢𝑢⁢𝑟,𝑤⁢ℎ⁡𝑖⁢𝑙⁢𝑒⁢𝑡⁢𝑟⁢𝑎⁢𝑐⁢𝑡⁢𝑜⁢𝑟⁢𝑠⁢𝑤⁢𝑖⁢𝑡⁢ℎ⁡𝑚⁢𝑜⁢𝑟⁢𝑒⁢𝑡⁢ℎ⁡𝑎⁢𝑛⁢10,000⁢ℎ⁡𝑜⁢𝑢⁢𝑟⁢𝑠⁢𝑠⁢ℎ⁡𝑜⁢𝑤⁢𝑜⁢𝑛⁢𝑙⁢𝑦⁢𝑎⁢𝑤⁢𝑒⁢𝑎⁢𝑘⁢𝑙⁢𝑦⁢𝑠⁢𝑖⁢𝑔⁡𝑛⁢𝑖⁢𝑓⁡𝑖⁢𝑐⁢𝑎⁢𝑛⁢𝑡⁢𝑑⁢𝑒⁢𝑐⁢𝑙⁢𝑖⁢𝑛⁢𝑒⁢𝑜⁢𝑓⁡𝑎⁢𝑏⁢𝑜⁢𝑢⁢𝑡2 per hour. We also document pronounced seasonal patterns, with …

Oregon State Rank Assessment For Wiens' Dwarf Mistletoe (Arceuthobium Abietinum Ssp. Wiensii), Lindsey K. Wise

Institute for Natural Resources Publications

Oregon state conservation status assessment for Wiens' dwarf mistletoe (Arceuthobium abietinum ssp. wiensii) using NatureServe methodology, 2026.

Comparative Field Efficacy Of Synthetic Insecticides And Plant Extracts Against Tuta Absoluta (Lepidoptera: Gelechiidae) In Lubumbashi, Dr Congo, Sylvain Ntambo Mbuya, Onesime M. Kankonda, Nyumah Fallah, Komivi S. Akutse, Marcellin C. Cokola

All Peer-Reviewed Publications

The invasive tomato leafminer, Tuta absoluta (Meyrick), is a very destructive pest that poses a major threat to tomato (Solanum lycopersicum L.) production in the Democratic Republic of Congo (DRC), causing extensive yield losses through larval feeding on leaves, stems, and fruits. Chemical insecticides remain the primary control method, but resistance development, biodiversity loss and environmental concerns necessitate alternative strategies. This study aimed at evaluating the efficacy of synthetic and botanical insecticides against T. absoluta during two consecutive cropping seasons 2023-2024 in Lubumbashi, DRC, under both dry and rainy season conditions. Two tomato seedling varieties (Tanya F1 and Tovi Star …

Behavioral And Molecular Effects Of 2,4-Dichlorophenoxyacetic Acid Exposure In Planarians, Emily Pintilie

Graduate Student Dissertations, Theses, Capstones, and Portfolios

The widespread use of pesticides, such as 2,4-dichlorophenoxyacetic acid (2,4-D), raises serious concerns about their effects on non-target aquatic organisms. In vertebrates, 2,4-D has been associated with neurotoxic outcomes. Planarians offer a valuable system for toxicological studies because of their well-characterized nervous system, regenerative capacity, and measurable behavioral responses. This study investigated the neurotoxic effects of 2,4-D exposure in the planarian species Girardia dorotocephala, including the assessment of nociceptive behaviors, survival rate, phototactic responses, and DNA methylation. Worms were exposed to various concentrations of 2,4-D (0–100 mg/L) at multiple time points. Nociceptive responses, such as scrunching, C-shapes, and seizures, …

The Detection Of Forever Chemicals From Paper Cups Using Colorimetry, Sara Miller

Graduate Student Dissertations, Theses, Capstones, and Portfolios

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals added to food packaging products to increase water-resistance and durability. PFAS are a growing concern due to their migration into beverages and foods and have been linked to cancer, immunotoxicity, and thyroid disturbances. The purpose of this study was to quantify PFAS migration from paper cups into water and evaluate toxic effects using planarians. PFAS detection was performed using a colorimetric assay, which forms a colored complex with PFAS, on: perfluorononanoic acid (PFNA), heptadeca fluorooctane sulfonic acid potassium salt (PFOS), perfluorooctanoic acid (PFOA). PFNA and PFOS showed absorbance at 640 nm, while …

Apoe Ε2 Potential Protection Against Long-Term Consequences Of Traumatic Brain Injury, Rebecca Faith Mesidort

Graduate Student Dissertations, Theses, Capstones, and Portfolios

Traumatic brain injury (TBI) can alter the quality of life, often resulting in cognitive decline, neurodegeneration, or death. There have been no biological advances to resolve the long-term consequences of TBI. The APOE ε2 gene is well known as a neuroprotectant against neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease. However, the biological mechanisms of how APOE ε2 protects against neurodegeneration are unknown. The purpose of this study is to investigate APOE ε2’s response to an environmental stimulus that leads to neurodegeneration, TBI, and further investigate APOE ε2’s biological mechanisms. After inflicting blunt force trauma to our model organism, …

Applied Reproductive Science: Technology, Ethics, And Management In Modern Animal Systems, Hagan Beach

Publications

This creative component course development project includes five (5) supplementary lessons focused on animal welfare concerns in livestock reproduction, biological foundations of ethical animal reproduction, responsible use of reproductive technology, ethical reproductive management, and ethical breeding decisions in livestock genetics. This resource also includes a teacher guide, supplementary instructional materials, assessment materials, implementation guidance, and reflection sections.

Together, these components give teachers a usable set of lessons and support materials for bringing ethical decision-making into animal science instruction. Although each lesson can stand on its own, the sequence was arranged to move from foundational reproductive science into more applied questions …

The Effects Of Water Quality On The Physiological Responses Of Daphnia Magna, Sara Al Shekha, Alexis Avila-Hernandez

COD Library Student Research and Award Symposium

After conducting research on the effects of water quality on the physiological response of Daphnia magna, a common freshwater invertebrate, the biological stress response significantly differed in heart rates among groups, which differed from the original hypothesis after exposing the invertebrates to various samples of local pond water.

Faculty Sponsor:  Professor Lynda Randa

Developing Antibodies Against Galectin-3 And Galectin-9 To Target Endometriosis, Ashleigh Burger, Noah Farnsworth, Jared J. Reisnouer, Cheyenne Vue

2026 Symposium

Endometriosis is a disease characterized by pelvic pain and the formation of endometrial-like tissue on the outside of the uterine lining. This condition affects nearly 10% of women across the globe and confirming whether someone has endometriosis requires visualization in surgery. While the specific causes of this disease remain unclear, the over-expression of the Galectins 3 and 9 in ectopic endometrial tissues suggests a role in the development and maintenance of the condition. Monoclonal antibodies (mAbs) are highly specific proteins with potential as diagnostic or treatment tools. The goal of this study is to generate antibodies against Gal3 and Gal9. …

Myocardin-Dependent Regulation Of Adam12 And Adam19 Promotes Fibronectin Fibrillogenesis During Pleural Fibrosis, Uday Siva Naga Sankar Allamneni

Biotechnology Theses

Pleural fibrosis involves excessive extracellular matrix (ECM) deposition driven by chronic injury and inflammation. Transforming growth factor-β (TGF-β) induces mesothelial–mesenchymal transition (MesoMT), promoting a myofibroblast phenotype. Our laboratory identified myocardin (Myocd), a transcriptional coactivator, as a key mediator of MesoMT that regulates ECM-remodeling proteases. RNA-seq and qPCR analyses showed that ADAM12 and ADAM19 are upregulated by TGF-β but suppressed by Myocd knockdown in Human pleural mesothelial and IPF-derived cells. Silencing ADAM12 reduced fibrotic markers, including fibronectin and smooth muscle actin (α-SMA), whereas ADAM19 showed relatively minor effects. ADAM12 knockdown also impaired fibronectin fibrillogenesis and insoluble matrix assembly, as confirmed by …

Synthesis Of A Nicotine-Like Backbone Ligand For Binding Evaluation At Plk-1 Pbd, Carter Johnson

Undergraduate University Honors Capstones

Cancer is a significant problem and requires continued research, as it remains one of the leading causes of death worldwide (Ramos, 2021). This capstone explores the synthesis and preliminary evaluation of a nicotine-type compound as a potential cancer-curing agent targeting the PLK-1 PBD protein using fluorescence polarization. The hypothesis is that a specific ligand may contribute to cancer research. This project also reviews cancer management methods while illustrating the discovery of chemical drugs used in chemotherapy. The project involves synthesizing and testing 3-((1-methylpyrrolidin-2-yl)methoxy)-1-alkylpyridin-1-ium, known as Compound C, to determine whether it can function as a potential cancer management agent. The …

Virtualizing Practical Science Education: A Sociological Analysis Of Undergraduate Teaching And Learning, Sina J. Fakoyede, Femi E. Babalola, Oluwatoyin T. Obateru, Oluwayemisi D. Akomolafe, Deborah O. Alabi, Stella K. Ekundayo

Higher Learning Research Communications

Objectives: The study aims to investigate the perspectives of university teachers and students on integrating practical science teaching with virtual learning in a multicultural and diverse society, specifically within the context of southwestern Nigeria.

Methods: A mixed-methods approach was employed, involving data collection from 100 university lecturers and 400 undergraduate students across 10 universities. Qualitative data were gathered through semi-structured interviews with lecturers and focus group discussions with students. Quantitative data were obtained via structured questionnaires, allowing for triangulation and comprehensive analysis.

Results: Findings revealed that certain lecturers showed preferential support influenced by students’ cultural backgrounds or academic behavior during …

The Brain Breakdown: Bringing Neuroscience To A Broader Audience, Katharine Buehrig

Undergraduate Honors Theses

Neuroscience is a rapidly growing field, which needs to continue becoming more accessible and understandable to younger generations. Expanding access to neuroscience through different modes, such as podcasts, brings the discipline to a broader audience. Podcasts allow listeners to follow an outlined learning path they can pursue on their personal timeline. High school students often do not have access to neuroscience specific materials within their standard science curriculum. To address this knowledge gap, I collected questions about neuroscience from high school students across four schools in the United States to develop an understanding about what they are interested in learning. …

Impact Of Land-Use Disturbances On The Composition Of Wetland Plant Communities Across The Conterminous United States, Maya Merchant

Undergraduate Honors Theses

Due to the threat of invasive species on wetland biodiversity, it is critical to assess factors driving their proliferation in wetlands. To address this growing need, this project analyzes relationships between non-native species and known anthropogenic disturbance types associated with increased biological invasions. Using the U.S. EPA’s 2021 National Wetland Condition Assessment, the relationship between non-native species (diversity, richness, and coverage) and surrounding land-use within 500, 1,000, and 3,000-meter buffers was evaluated. To explore patterns across larger spatial scales, mean non-native species diversity, richness, and coverage was calculated at the watershed level and compared to associated percentages of agricultural land …

Accesstem: How Small Colleges Can Open Stem Pathways For Local High School Students, Dina D. Isakov

Program in Community Action (PICA)

This paper reflects my experience developing ACCESStem as part of the Program in Community Action (PICA) center at Connecticut College. ACCESStem is a community-engaged research project designed to create hands-on, lab-based STEM workshops for local high school students in New London. ACCESStem was built on the premise that even small liberal arts colleges can hold a meaningful impact on helping diversify the science workforce. Over the course of three years, this project took shape through my relationships with STEM faculty on campus and relationships with staff at the Holleran Center for Community Action. This paper works to begin contextualizing the …

Cell Cycle Inhibition: Illudin S And Its Effects On Cdk2 In Ewing Sarcoma, Stephanie Diez, Natalie Flores, Alexandria Hernandez, Viviana Palacios, Terry Jo Shackleford

Cell and Molecular Methods

Ewing Sarcomas are aggressive round cell mesenchymal neoplasmas that have a high occurrence in children and young adults. CDK2 is a protein that is involved in the G1 phase of the cell cycle, which promotes the transition to the S phase. CDK2 kinase activation is mainly observed in the G1/S-phase transition.3 CDK2 binds to Cyclin proteins is responsible for entry and progression, thereby leading to maximal apoptosis activity in the S-phase. Illudin S is a drug that has been known to target cancer-specific cells, such as leukemia. Illudin S, in general are a cytotoxic metabolite that comes from plants, specifically …

Yap1 Knockdown And Panobinostat Treatment Increase Apoptotic Response And Decrease Gene Expression In Ewing Sarcoma Cells, Luna Collazo-Garcia, Alejandra Favela Santos, Madeline Torres-Salazar, Isabella Toscano, Terry Jo Shackleford

Cell and Molecular Methods

Ewing sarcoma (EWS) is considered to be one of the most aggressive pediatric malignancies, often characterized by its dysregulated gene expression driven by oncogenic fusion proteins. The Hippo signaling effector Yes-associated protein 1 (YAP1) has been known in promoting cell proliferation, survival, and therapeutic resistance in multiple cancers. However, its role in Ewing sarcoma response to treatment remains unclear. This study investigated whether YAP1 knockdown enhances the sensitivity of Ewing sarcoma cells to the histone deacetylase inhibitor Panobinostat. Ewing sarcoma, ES8, cells were transfected with a YAP1-targeting siRNA (siYAP1) or a non-targeting control (siControl) and treated with DMSO, 0.1 μM, …

Everolimus Treatment Combined With Akt1 Knockdown Increased Apoptosis And Decreased Cell Proliferation In Ewing Sarcoma Cells, Arisha Arif, Alfie Barcenez, Sophia Ruter, Nicole Vanegas-Riddick, Terry Jo Shackleford

Cell and Molecular Methods

The purpose of this study is to use the gene AKT1, due to the interest in AKT1’s role in cancer cell proliferation, and the drug Everolimus, to determine if combined targeted therapy works as a more efficient therapeutic approach. Ewing Sarcoma has been connected to chromosomal translocations and is most common in pediatric patients. It is most often treated with chemotherapy and local treatments. It may be connected to the gene AKT1 due to how it regulates cell metabolism, growth, and proliferation. The gene mTOR is similarly connected to cell metabolism and proliferation, and is inhibited by the drug Everolimus. …

Sirna Knockdown Of Rptor Reduces Rptor Expression, Increases Brd4 Expression, And Alters Proliferation And Apoptosis In Ewing's Sarcoma Cells, Sergio Cipriano, David Leavitt, Michael Olivia, Liam Valdez, Terry Jo Shackleford

Cell and Molecular Methods

Ewing sarcoma is a highly aggressive cancer that primarily affects children and young adults. Although treatment options exist, many patients do not respond effectively, showing the need for improved targeted therapies. RPTOR is a key in mTORC1 complex which regulates cell growth, proliferation, and survival. LY2874455 is a selective pan-FGFR inhibitor that targets growth factor signaling pathways involved in tumor progression, and FGFR signaling interacts with pathways such as mTOR, making it a potential target for combination therapies. We hypothesized that silencing RPTOR in Ewing sarcoma cells would disrupt mTOR signaling and alter expression of genes linked to cell survival …

Everolimus And Sirna-Mediated Mtor Inhibition Reduces Proliferation And Promotes Apoptosis In Ewing Sarcoma Cells, Dylan Calvert, Malorie Martinez, Alexa Miner, Ellis Quiroga, Terry Jo Shackleford

Cell and Molecular Methods

Ewing Sarcoma (ES) is an aggressive pediatric bone cancer characterized by rapid cell proliferation and poor prognosis, making the identification of therapeutic targets critical. One of  the mechanistic targets is rapamycin (mTOR) signaling pathway, which is critical for regulating cell growth, proliferation, and survival. Abnormal activation of the mTOR signaling pathway has been linked to the progression of ES, as it drives uncontrolled cell growth and apoptosis resistance. Because mTOR represents a promising therapeutic target for ES treatment, we hypothesized that inhibiting mTOR activity through an siRNA-mediated knockdown or through Everolimus drug treatment, would reduce cell proliferation and promote ES …

Effects Of Combined Action Observation, Motor Imagery, And Neuromuscular Electrical Stimulation On Muscle Strength And Size During Short-Term Upper Limb Immobilization, Zahra Pourhatami

Theses - ALL

Short-term limb immobilization induces rapid declines in muscle strength that exceed reductions in muscle size, suggesting a dominant role of neural mechanisms in early functional decline. Interventions capable of simultaneously targeting central neural and peripheral muscular pathways may therefore offer superior protection during disuse, yet such combined approaches remain unexamined in upper limb immobilization models. To investigate the effects of combined action observation with motor imagery (AOMI) and neuromuscular electrical stimulation (NMES) (AOSTIM) on muscle strength, size, and quality during 7 days of upper limb immobilization, we conducted a study in healthy young adults. Forty-three healthy young adults were randomly …

Nanoparticle-Based Therapy For Peripheral Artery Disease: Evaluation Of Collagen Reduction And Fibrosis Mitigation In Ischemic Tissue, Tresha Nguyen

2026 Spring Honors Capstones Projects

Peripheral Artery Disease (PAD) is characterized by reduced blood flow, ischemic injury, and fibrosis, which collectively impair tissue function. Current treatment strategies are limited in their ability to target fibrotic tissue and restore normal function effectively. This study evaluates the therapeutic potential of drug-loaded nanoparticles to reduce fibrosis in ischemic tissue. Nanoparticles were synthesized and characterized for in vivo application. Tissue samples from experimental groups, including saline control, blank nanoparticles, free drug, and drug-loaded nanoparticles, were analyzed using Masson’s Trichrome staining to quantify collagen deposition. Histological images were processed using image analysis software to determine the percentage of collagen area. …

Buying Intention Of True Price Labelled Food Products For Different Motive-Based Consumer Segments, Machiel J. Reinders, Houkje Adema, Liam Dwyer, Ellen J. Van Loo

Department of Agricultural Economics Faculty Publications

No abstract provided.

Co-Designing Sweettexts: An Intake-Driven Sms Intervention To Reduce Free-Sugar Consumption In Preschoolers, Bervelyn Asantewaah Addo

Theses - ALL

Abstract Introduction: As early childhood represents a crucial window for establishing lifelong dietary patterns, excessive intake of sugary foods and beverages during this period may result in long-term adverse health outcomes. Intake levels continue to exceed recommended guidelines, and disparities within and across race and low-income population groups persist. Given these disparities, targeted interventions developed to consider the unique needs, preferences, and cultural differences in diverse population groups are essential to enhance health and well-being. The purpose of this research was to develop the content of the "SweetTexts", a text-message-based intervention to reduce the intake of free sugar among preschool-aged …

The Role Of Creatine Supplementation On Neuromuscular Function, Mark Petry

Theses - ALL

This study examined the effects of short-term high-dose creatine monohydrate (CrM) supplementation on neuromuscular and corticospinal function in healthy adults. Creatine is widely recognized for its role in enhancing muscular performance and energy availability, yet its short-term effects on neural and neuromuscular outcomes remain unclear. The purpose of this investigation was to determine whether three days of CrM loading would influence maximal voluntary contraction (MVC) peak torque, corticospinal excitability (CSE) measured via transcranial magnetic stimulation (TMS)-induced motor evoked potential (MEP) amplitude, muscle cross-sectional area (CSA) and muscle quality via echo intensity (EI). Nine healthy creatine-naive adults completed a repeated-measures design …

In Memoriam: Madhav Gadgil, Editorial Board

The International Journal of Ecopsychology (IJE)

No abstract provided.

Book Review--Luke Kemp’S Goliath’S Curse: The History And Future Of Societal Collapse (2025). Ny: Alfred A. Knopf.

The International Journal of Ecopsychology (IJE)

No abstract provided.

Disability: An Autopathography, Isabell A. Collins

The International Journal of Ecopsychology (IJE)

No abstract provided.

Editorial 12(1), May 2026, Matthew R. Jamnik

The International Journal of Ecopsychology (IJE)

No abstract provided.

Artist Interview: Sarah Crooks, Sarah Crooks

The International Journal of Ecopsychology (IJE)

No abstract provided.