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Influence Of Patch Characteristics On Pollinator Behavior And Seed Production In Centaurea Stoebe, Abigail Hiltke

Theses - ALL

Discontinuous, or patchy, landscapes may affect pollinator foraging behaviors and could potentially lower the fitness of isolated plant communities by limiting and/or altering pollination services. I tested this idea by examining changes in pollinator behavior in patches of spotted knapweed of different size, flower density, and distance from one another. Based on predictions from optimal foraging theory, I identified and measured key pollination promoting behaviors that may change when foragers are exposed to discontinuous landscape. These behaviors were pollinator visitation rates to patches, the number of visits to individual flowers within patches, and the handling time per flower. These factors …

Mechanism Of Impaired Cd8+ T Cell Activation During Ross River Virus Infection, Christopher Bullock

Arts & Sciences Graduate Student Theses and Dissertations

Ross River virus (RRV) is a mosquito transmitted virus endemic to Australia that infects humans and causes acute symptoms of rash, fever, myalgia, and fatigue. Although systemic viral infection subsides within a few weeks, joint pain lingers in many patients for months. Active viral replication is not readily detected in this chronic phase, although persistent viral RNA has been found in the synovial fluid of patients. This can be studied in mice, which can be productively infected with RRV when inoculated in the foot. Like in humans, in the chronic phase of disease, viral RNA is still present in the …

Studying The Dynamics Of Neuromodulators In The Brain By Fluorescence Lifetime Imaging, Pingchuan Ma

Arts & Sciences Graduate Student Theses and Dissertations

Neuromodulators in the brain are fundamental to neuronal functions and animal behaviors in health and diseases. The modulatory actions of neuromodulators highly rely on their spatiotemporal dynamics. Recent research has demonstrated the importance of both sustained and transient change in neuromodulators, likely due to tonic and phasic neuromodulator release. However, no traditional methods could simultaneously record both types of dynamics. Fluorescence lifetime of optical reporters could offer a solution because it both allows high temporal resolution and is impervious to sensor expression differences across chronic periods. Nevertheless, no fluorescence lifetime change across the entire classes of neuromodulator sensors was previously …

Exploring The Homeostatic Functions And Driving Forces Of Lymphatic Outflow Pathways From The Central Nervous System, Zachary Matthew Papadopoulos

Arts & Sciences Graduate Student Theses and Dissertations

Lymphatic drainage from the central nervous system (CNS) has been noted and described for several hundred years, yet its physiological roles have remained unclear. The fluid homeostasis of the CNS has long stood as an area of scientific interest due to primary disorders including hydrocephalus. However, the early days of neuroimmunology leaned on the lack of lymphatic vasculature in the CNS as a contributing explanation for ‘immune privilege’ in the CNS. As a result, the importance of lymphatics in CNS homeostasis has remained poorly understood and controversial. Following a renaissance in interest in the contribution of lymphatics to CNS homeostasis, …

A Filter-Based Model Of Visual Recognition, Olivia Rose Bockler

Arts & Sciences Graduate Student Theses and Dissertations

Visual recognition, a key perceptual process, enables primates to identify faces, food, tools, and potential threats in their environment. Cortical neurons along the ventral visual stream—spanning from early visual cortex (V1) through inferotemporal cortex (IT), with long-range projections to ventrolateral prefrontal cortex (vlPFC)—are essential for visual recognition. Traditional models propose that neuronal representations increase in complexity in each stage of this pathway, culminating in object-specific representations in higher-order cortex. However, this hypothesis remains debated, particularly as artificial visual models have countered that individual neurons along this pathway may function more as filters contributing to distributed representations of objects. Thus, this …

Aging, Fast And Slow: Gene Expression Signatures Of Physiological Age Vs. Future Lifespan In Caenorhabditis Elegans, Matthew Mosley

Arts & Sciences Graduate Student Theses and Dissertations

An outstanding question in the field of aging biology is the origin of variability in lifespans among members of the same species. Traditional wisdom dictates that differences in one individual’s genes or environment, “nature” and “nurture,” could predispose that individual to a long or short life. However, these explanations are radically incomplete. Even in a model system as homogenous as C. elegans, using an isogenic population in a lab-controlled environment, we observe a distribution in lifespans comparable to that seen in outbred human populations. The first part of this dissertation focuses on characterizing this non-genetic, non-environmental variability in the aging …

Technology Development Of High-Resolution Single-Cell Lineage Tracing For Cell Reprogramming Systems, Sadie Vanhorn

Arts & Sciences Graduate Student Theses and Dissertations

A critical element of cell identity is the cell that created the observed cell. This parent cell dictates many aspects of its identity, whether measured by function, phenotype, or specific assays. The cell’s lineage impacts the ability of the cell to differentiate into final cell types in development or successfully reprogram in direct cell reprogramming. Here, we evolve molecular barcoding techniques to increase the resolution of lineage recording at single-cell resolution. Using single-cell RNA-sequencing as the readout for this measurement, polyadenylated reporter gene transcripts with engineered 3’ untranslated regions were designed to initially label and then record lineage information. While …

Gene Expression Regulation By Au-Rich Elements And Au-Rich Element Binding Proteins, Courtney Fay Jungers

Arts & Sciences Graduate Student Theses and Dissertations

The regulation of messenger RNA (mRNA) splicing, stability, and translation efficiency are major modes for controlling gene expression – which is essential for life. RNA-binding proteins (RBPs) and microRNAs (miRNAs) are trans-acting factors that bind to cis-elements influencing the stability and translation of the mRNA transcript. AU-rich elements (AREs) are cis-elements that are targeted by AU-rich element binding proteins (ARE-BPs). Here, I show a novel role for AREs and AU-rich element binding protein 1 (AUF1) during alternative splicing and report on interactions of RBPs and miRNAs to design a new treatment for breast cancer by interrupting these interactions in the …

Achieving Inter- And Transdisciplinarity In Ecohealth: Insights From A Rodent-Borne Disease Project In A Polycrisis Era, Isabelle Arpin, Clémence Massart, Vincent Bourret, Guillaume Castel, Valeria Carolina Colombo, Jana Eccard, Jasmin Firozpoor, Maciej Grzybek, Heikki A. Henttonen, Herwig Leirs, Andrew Mcmanus, Ben Roche, Tarja Sironen, Vincent Sluydts, Peter Stuart, Annetta Zintl, Nathalie Charbonnel

Publications

Introduction: Inter- and transdisciplinary research (ITDR) is increasingly promoted to address “wicked problems”, particularly in health sectors adopting approaches like Ecohealth. Our Ecohealth-inspired project on rodent-borne diseases, initiated just before the COVID-19 pandemic, provided an opportunity to evaluate ITDR implementation.

Methods: We employed a recently developed semi-quantitative evaluation method to measure our project’s success in achieving ITDR and analyzed factors influencing this achievement.

Results: The project showed strengths in system description, team task allocation, and data sharing, but had lower scores in engaging societal actors throughout the project cycle.

Discussion: We identified the underexplored influence of problem wickedness as a …

Water Quality Assessment Of Three Ponds In The Plaster Creek Watershed, Orin Daspit, Salome Giessmann, Kennedi Pepin, Andrew Slagter, Sydney Wagenmaker

Student Papers and Reports

Ponds are commonly found in urban areas serving as both an aesthetic and ecological feature. The water quality of these ponds can make important contributions to the overall health of the watershed in which they reside. This study analyzes three ponds within the Plaster Creek Watershed: the Southbridge Condominium Association Pond, the Calvin University Seminary Pond, and the Calvin University Ecosystem Preserve Kettle Swamp. This project aims to provide the Southbridge Condo Association with data that will inform future remediation actions. Using water samples collected over three days, E. coli, pH, nutrients, and total dissolved solids were measured in each …

Avian Adaptation To Thermal Gradients, Justin Wheeler Baldwin

Arts & Sciences Graduate Student Theses and Dissertations

Life on Earth has adapted to extremely different temperatures worldwide. However, across distant branches of the tree of life, animals in similar temperature environments often share similar phenotypic traits. Specifically, traits that bear on the ratio between an individual’s surface area (e.g. appendage length) and its volume (e.g. body size) are particularly important for temperature regulation and are codified in canonical biogeographical rules. Although these global patterns of finding larger-bodied (Bergmann’s Rule) and shorter-limbed (Allen’s Rule) animals in colder regions are widely upheld, they also show substantial variation. It remains poorly understood why some animals conform to these biogeographical rules …

Sustainable Plastics From Plastic Metabolisms: Leveraging Purple Non-Sulfur Bacteria For Polyhydroxyalkanoate Synthesis, Eric Michael Conners

Arts & Sciences Graduate Student Theses and Dissertations

Purple non-sulfur bacteria (PNSB) are a taxonomically diverse group of gram-negative bacteria representing some of Earth’s most metabolically versatile life, with many genera capable of switching between the four major metabolic modes – chemoheterotrophy, chemoautotrophy, photoheterotrophy, and photoautotrophy. Today, we exploit this diversity to explore fundamental questions about microbial metabolism. At the same time, many researchers are eager to use PNSB as tools for biotechnological innovations. Yet there exists a gap between fundamental biology and applied science. Part of the challenge is that we rely on a handful of model organisms – namely, members of the genera Rhodopseudomonas and Rhodobacter …

Pmp2+ Scs Maintain The Survival And Functioning Of Large-Caliber Motor Axons, Mikolaj Kozlowski

Arts & Sciences Graduate Student Theses and Dissertations

Neurodegenerative diseases are characterized by selective neuronal vulnerability, a phenomenon in which a specific pathology induces the death of a particular subpopulation of neurons. For example, selective neuronal vulnerability in the peripheral nervous system results in sensory, motor, or mixed peripheral neuropathies. While the intrinsic differences between neuronal subtypes cannot fully explain the basis of selective neuronal vulnerability, it is plausible that it partially stems from neuron extrinsic mechanisms such as the malfunction of distinct Schwann cell (SC) subtypes. Recently, we identified an exciting subpopulation of myelinating SCs characterized by the expression of Adamtsl1, Cldn14, and Pmp2 (hereafter referred to …

Bat Activity Across Urban Forest Plantings In Lexington, Kentucky, Grayson Marie Collier

Online Theses and Dissertations

Urbanization has led to major forest loss and negatively impacts ecosystem services. Urban reforestation efforts, such as Reforest the Bluegrass (RTB) in the Lexington-Fayette metropolitan area of Kentucky, have been implemented to address these negative effects, and to create habitat for forest-dependent wildlife such as bats. My research focused on assessing differences in bat activity across a 20-year chronosequence of RTB sites. Acoustic detectors were deployed across 10 different-aged plantings at 60 randomly-defined detector locations. Each planting was surveyed across 8 sampling periods from May – August 2023. Each recording session spanned ca. 7 consecutive nights, yielding a total of …

The Activity And Origin Of The Chitinases In The Gut Of The Mediterranean House Gecko, Alec John

Masters Theses (Archived)

Chitin is a major component of the exoskeleton of arthropods as well as the cell wall of fungi. This amino polysaccharide polymer provides structure and protection to these organisms and represents a significant barrier to digestion of arthropod prey and fighting fungal infections. Chitinases are enzymes that break down chitin. Smaller insectivores, based upon the higher surface-to-volume ratio of their even smaller prey, ingest a large amount of chitin per unit prey item. Therefore, they represent high-likelihood opportunities to bio prospect for novel chitinases that may be effective against pathogenic fungi. Fungal infections are notoriously difficult to treat, and they …

Comparing Multivalent Cross-Linked Sodium Alginate/ Montmorillonite Beads Containing Curcumin Or Cayenne Pepper As Drug Carriers And Their Antimicrobial Resistance, Shionainn Traynor, Shubham Sharma

SURE Journal: Science Undergraduate Research Experience Journal

The aim of the following work was to investigate and compare curcumin and cayenne pepper in microbeads composed of sodium alginate (SA) crosslinked with montmorillonite (MMT) to act as drug carriers and their antimicrobial resistance. The microbeads were prepared through ion-exchange in multivalent solutions of CaCl₂, MgCl₂ and AlCl₃. The microbeads were characterized by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray analysis (EDX) and the time required for intercalation of curcumin and cayenne pepper with MMT. Simulated intestinal fluid (pH 7.3) and gastric fluid (pH 1.2) at 37°C were used for comparison in swelling studies. …

Investigation Into The Effect Of Aspartame On The Expression Of P53 And Bax In Mouse Stomach Tissue, Angelique Cheryl, Aoife Mac Cooey

SURE Journal: Science Undergraduate Research Experience Journal

Introduction: The recent reclassification of aspartame as a Group 2B hazard by the International Agency for Research on Cancer, along with studies suggesting links to cancer, has raised concerns and prompted further investigation. Evidence suggests that aspartame exposure may alter p53 and BAX gene expression, affecting apoptosis in cancer cells. This study aims to examine how aspartame exposure affects p53 and BAX gene expression in normal mouse stomach tissue, shedding light on cellular stress and apoptosis mechanisms.

Methods: Mice were sacrificed, and stomach tissue was excised and divided into control and treatment groups. RNA extraction was carried out in the …

Editorial - Sure Journal Vol 6, Anne M. Friel, Eva Campion, Sinead Loughran

SURE Journal: Science Undergraduate Research Experience Journal

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Technological Accessibility For Wildlife Telemetry Research, Andrew Danielson

The Journal of Purdue Undergraduate Research

Over the course of two years, I conducted original research into improving accessibility for researchers in the field of wildlife telemetry. Wildlife telemetry is a technique used by biologists to track wildlife in the field, which requires the biologist to attach a small radio transmitter to an animal, usually using a specially designed collar, harness, or another means. These transmitters are battery powered and will emit or transmit a regularly timed radio signal that can be received by radio receivers carried by the researchers. Two issues faced by wildlife telemetry researchers are the cost of wildlife telemetry equipment and the …

Coastal Marine Heatwaves In The Santa Barbara Channel: Decadal Trends And Ecological Implications, Kit Yu Karen Chan, L. Kui, A. M. Mcdonald, A. L. Ritger, G. E. Hofmann

Biology Faculty Works

Marine heatwaves (MHWs) are of increasing concern due to the emerging ecological and socioeconomic impacts on coastal ecosystems. Leveraging the data of the Santa Barbara Coastal Long-Term Ecological Research project, we analyzed the MHW event metrics observed in the kelp forest ecosystem and across Santa Barbara Channel, CA, USA. Not only was there a significant positive trend in the number of MHWs recorded, their duration and intensity were also increasing over time. MHWs were detected year-round, suggesting that marine organisms have exposure risks regardless of their phenology. Exposure at one life history stage could have a legacy effect on the …

A Mini Review Of Plant Tissue Culture: The Role Of Media Optimization, Growth Regulators In Modern Agriculture, Callus Induction And The Applications, Norrizah Jafaar Sidik, Hasan M. Agha, Abdulmutalib Alabeed Alkamil, Muneer Mohammed Saleh Alsayadi, Amjad Abdulhadi Mohammed

AUIQ Complementary Biological System

Plant tissue culture is an innovative biotechnological approach developed to meet the escalating global demand for agricultural production with enhanced nutritional value. This aseptic, in vitro technique allows for the cultivation of plant cells, tissues, or entire plants under controlled environmental and nutritional conditions, facilitating the generation of genetically identical clones. The method is indispensable in preserving endangered plant species, boosting crop yield and quality, and enabling year-round production of disease-free plants. Central to plant tissue culture is the composition of the growth medium, which must include a precise balance of macronutrients, micronutrients, amino acids, vitamins, and plant growth regulators …

Development Of Novel Nanocarriers With Multi Modal Action Against Lung Cancer, Gayathri K

Theses and Dissertations

Lung cancer ranks among the top causes of cancer-related deaths worldwide. The deteriorating environment and unhealthy lifestyle in the modern era has further contributed to the exponential increase in lung cancer incidence across the globe. Lung cancers fall under two major types based on the location of the tumour in the lung namely, small-cell lung cancer (SCLC) which is more aggressive, and non-small-cell lung cancer (NSCLC) which is more prevalent. Late diagnosis has been a major cause for poor prognosis as the cancer is detected only in an advanced stage.

Conventional therapies like chemotherapy, surgery and radiotherapy against lung cancer …

Beyond The Bench: Redefining Research Impact In Society, Nouran Amin

Purdue Journal of Service-Learning and International Engagement

The following essay reports on the reflective experiences of the author’s time completing a certificate program “Advancing Graduate Research Impact in Society” offered by Purdue University’s Office of Community Engagement in Fall 2023. It begins by narrating the author's journey as a Muslim woman in STEM spaces, highlighting the lack of relatable role models and the ensuing dissonance between aspirations and prevailing narratives. Through introspection, the essay progresses to examine the paradox of publicly funded but inaccessible science, which often fails to engage with community needs and priorities. The essay underscores the importance of inclusivity and diverse representation in scientific …

Elucidating The Role Of Astrocytes In Norepinephrine Neuromodulation, Katheryn Bry Lefton

Arts & Sciences Graduate Student Theses and Dissertations

Norepinephrine, a wakefulness-associated neuromodulator, profoundly reshapes neural systems, from synaptic circuits to behavior. Through decades of research, a substantial catalogue on the effects of noradrenergic signaling on behavior and networks has been generated. How norepinephrine remodels synaptic circuitry is widely thought to underlie the larger changes in neural networks and behavior, highlighting the need for a more thorough understanding of the circuit effects of norepinephrine neuromodulation. However, the mechanistic details of the norepinephrine on synapses are still unclear. In recent decades, a large body of work has shown that norepinephrine acts not just on neurons, but on glial cells including …

The Effect Of Dha On Myo-Inositol Levels In Lymphoblasts Derived From Patients With Bipolar Disorder, Katherine Pierre

Honors Theses

Bipolar disorder is a mood disorder that is characterized by recurring episodes of mania and depression. Bipolar I disorder is accompanied by severe episodes of mania and depression, while bipolar II disorder is characterized by a milder form of mania. It has been hypothesized that currently approved treatments for this disorder, lithium and valproic acid, exert their therapeutic effect by decreasing myo-inositol levels intracellularly. However, these treatments may lead to undesired side effects, creating a need for safer treatments. Omega-3 fatty acids are polyunsaturated fats that have been shown to be effective in relieving symptoms of bipolar disorder.

To investigate …

New Species And Records Expand The Checklist Of Cellular Slime Molds (Dictyostelids) In Jilin Province, China, Zhaojuan Zhang, Liang He, Yuqin Sun, Zhuang Li, Yingqun Yang, Chao Zhai, Steven Lee Stephenson, Xiangrui Xie, Yu Li, Pu Liu

Biological Sciences Faculty Publications and Presentations

Dictyostelids represent a crucial element in the protist community, and their abundant presence in Jilin Province underscores their indispensable role in biodiversity conservation. In the present study, a resource survey of dictyostelids used random sampling to collect 28 soil samples from five localities in Changbai Korean Autonomous County, Jilin Province. In addition, a compilation of dictyostelid species reported from Jilin Province was developed, based on a thorough review of the literature. The survey yielded fifteen isolates of dictyostelids, comprising six species from four genera. Notably, two new species (Dictyostelium longigracilis sp. nov. and Dictyostelium macrosoriobrevipes sp. nov.) were described using …

Study Of The Brain Anatomy Of Three Extinct Marsupials: Thylacinus Cynocephalus, Thylacoleo Carnifex, And Silvabestius Johnnilandi, Francisco Garcia

Honors Program Theses and Research Projects

Marsupials are pouched mammals that today are mainly found in Australasia and South America. Marsupials have proven to be quite intriguing to evolutionary biologists who note how some marsupials resemble placentals in anatomy due to convergent evolution, with both marsupials and placentals filling similar niches in their respective environments. As of today, studies interested in marsupial brain evolution have published descriptions of cranial endocasts for several species of marsupials, with the number of descriptions seeing a massive boost over the last 20 years with the arrival of CT imaging technology. However, no comprehensive study of brain evolution in marsupials has …

Studies Of Media To Maximize The Expression Of Bacterial Metalloprotease Genes As Potential Therapeutics For Human Alzheimer’S Disease, Uday Kiran Chigurupati

Honors Capstones

This study investigates the potential of bacterial metalloprotease genes as therapeutic agents for Alzheimer's Disease (AD). The research focuses on Pseudomonas 20ei1 (P. 20ei1), a bacterial species isolated from lagoon water, which contains pitrilysin genes that share similarities with human insulysin. Six pqqL-related genes were identified in P. 20ei1 for this study. The research methodology involved bioinformatic studies, bacterial cell culture in various media, RNA extraction, purification, and cDNA synthesis. Quantitative PCR analysis was performed to analyze gene expression levels in different cDNA samples. The bacteria grown in the medium with insoluble phosphate has shown higher expression of selected genes …

Simple Improvements In Vector Design Afford Substantial Gains In Aav Delivery Of Aggregation-Slowing Aβ Variants, Ella Borgenheimer, Cameron Trueblood, Bryan L Nguyen, William R Lagor, Joanna L Jankowsky

Faculty, Staff and Students Publications

Adeno-associated virus (AAV) gene therapy for neurological disease has gained traction due to stunning advances in capsid evolution for CNS targeting. With AAV brain delivery now in focus, conventional improvements in viral expression vectors offer a complementary route for optimizing gene delivery. We previously introduced a novel AAV gene therapy to slow amyloid aggregation in the brain based on neuronal release of an Aβ sequence variant that inhibited fibrilization of wild-type Aβ. Here we explore three coding elements of the virally delivered DNA plasmid in an effort to maximize the production of therapeutic peptide in the brain. We demonstrate that …

Deciphering Immune Suppression Mechanisms Of Primary And Metastatic Breast Cancer, Seunghyun Lee

Arts & Sciences Graduate Student Theses and Dissertations

Immune checkpoint blockade (ICB) has revolutionized cancer treatment, receiving FDA approval for various previously incurable cancers. In breast cancer, the combination of pembrolizumab (an anti-PD-1 antibody) with chemotherapy has become the standard-of-care for early-stage (Keynote-522) and advance-stage (Keynote-355) triple-negative breast cancer (TNBC). Unfortunately, over 30% of TNBC patients fail to respond to the combined chemo-immune therapy treatment, and the causes are unknown. Furthermore, ICB has demonstrated poor results in hormone-receptor positive breast cancer. While it is well-established that breast cancer cells can evade immune responses, the specific mechanisms driving immune evasion remain unclear. Thus, deciphering the immune system's role in …