Biology Commons^™

Assessing The Effects Of Remaining Northern California Kelp Forest Mesopredators On Purple Sea Urchin Abundance, Distribution, And Feeding Activity, Sandra E. Traverso

Cal Poly Humboldt theses and projects

Kelp forests are threatened by regional abiotic and biotic stressors, including overgrazing by sea urchins. On the north coast of California, purple sea urchins (Strongylocentrotus purpuratus) are prolific grazers of kelp and with the regional extinction of their main predator (sunflower stars, Pycnopodia helianthoides), it is unknown whether any remaining mesopredators could exert top-down control of purple urchin populations. Other known predators of purple urchins in northern California include rock crabs, which have been shown to control sea urchin populations in Atlantic urchin barrens and indirectly cause phase shifts back to kelp forests. Yet, little is known …

Interactions Between New Zealand Mud Snails (Potamopyrgus Antipodarum) And Toxic Cyanoabacteria (Anabaena) In Baduwa’T (Mad River), Humboldt County, California, Cecilia F. Kennelly

Cal Poly Humboldt theses and projects

Invasive species in freshwater systems are circulated around the globe, wreaking havoc on natural communities. The New Zealand mud snail (Potamopyrgus antipodarum) is a very successful aquatic invader that has established populations in freshwater streams, lakes, and rivers around the globe. The goal of this project was to evaluate the interactions of invasive New Zealand mud snails (NZMS) and toxic cyanobacteria Anabaena in the Mad River in Humboldt County, California. These two species of concern are found in similar habitats along the river, but their whether NZMS consume Anabaena or affect toxin production is unknown. First, I conducted …

Using Habitat Modeling To Locate New Populations Of Dunn's Salamander (Plethodon Dunni) Near Its Southern Geographic Range Limit, Mary A. Mackey

Cal Poly Humboldt theses and projects

Habitat suitability models were utilized to direct survey efforts for Plethodon dunni in Northern California. Two models were created, one using traditional statistical methods (GLM or Generalized Linear Modeling) and the other using a machine learning method (MaxEnt or Maximum Entropy modeling). Plots were selected from areas of agreement and disagreement between the models to carry out presence surveys. The MaxEnt model yielded better predictions than the GLM model. The two models had three variables in common (annual temperature range, precipitation of driest month, and precipitation seasonality) and predicted suitable habitat within the known range of P. dunni. The …

A Case Of Incipient Budding Speciation In The California Floristic Province, Infraspecific Divergence In Abronia Villosa, Eli J. Allen

Cal Poly Humboldt theses and projects

Physical barriers to gene flow are the traditional evidence for species divergence. Conversely, there has been increasing acknowledgment of speciation in the face of gene flow as an evolutionary process. Budding speciation involves peripheral populations adapting to local ecological conditions, thereby budding off from a widespread progenitor species. Budding speciation is distinguished by ecological divergence and is generally evidenced by asymmetrical range size and nested phylogenetic relationships of sister species. The narrow endemic Abronia villosa var. aurita is adapted to montane sandy washes adjacent to its widespread sister variety, the desert dwelling var. villosa. Here, I tested the hypothesis …

An Inhibitory Recurrent Network In The Olfactory System, Farzaan Salman

Graduate Theses, Dissertations, and Problem Reports (ETD)

Neuromodulatory circuits are a necessary component of neural flexibility as they are able to act differentially depending on the receptors expressed by their downstream targets. Identifying the synaptic partners of modulatory neurons and determining the neurotransmitter and receptor content of these partners is necessary to identify the rules governing neuromodulatory circuits. In this study, I characterized the circuit of the contralaterally projecting, serotonin-immunoreactive deutocerebral neurons (CSDns), the sole synaptic source of the neuromodulator serotonin in the olfactory circuit of Drosophila melanogaster, by identifying the strongest synaptic partners of the CSDns, and the expression of genes encoding neurotransmitters and receptors of …

Cerebellar Feedback Effects On Responses To Conspecific Signals Of Different Frequencies In The Electrosensory System, Elora K. Shinn

Graduate Theses, Dissertations, and Problem Reports (ETD)

Sensory systems in animals have evolved to translate physical stimuli into neural representations that, in turn, guide behavior. Feedback is critical in these processes, allowing organisms to filter redundant information and respond effectively to relevant stimuli. In humans, for example, the cerebellar flocculus provides feedback to the vestibulo-ocular reflex to stabilize eye movements during body rotation. In bats, the feedback during echolocation helps prioritize essential signals from the environment. In weakly electric fish, cerebellar feedback helps filter out redundant low-frequency modulations caused by conspecifics, enabling them to detect prey and other relevant signals. However, the influence of cerebellar feedback on …

Investigation Of L-Serine Synthesis And Transport As Stabilizing Feedback Mechanisms Within The Tsetse-Wigglesworthia Symbiosis, Ryan Phillips

Graduate Theses, Dissertations, and Problem Reports (ETD)

Tsetse flies (Glossina morsitans), which are the obligate vectors of Old-World trypanosomes (Trypanosoma spp.) that cause African trypanosomiasis, have a bacteriome that houses the intracellular endosymbiont Wigglesworthia glossinidia. The ancient coevolution of these species has led to the integration of Wigglesworthia metabolism into tsetse physiology and a subsequent reliance on nutrient exchange for maintaining the fitness of both partners. The establishment of this obligate mutualism has facilitated the emergence of feedback mechanisms that stabilize the symbiosis, such as that which involves the exchange of L-serine and B vitamins. The Gammaproteobacteria Wigglesworthia supplement B vitamins lacking …

An Investigation Into Secondary Transfer Of Trace Dna To Evidentiary Items Via Nitrile Gloves During Crime Scene Examination, Molly G. Younker

Graduate Theses, Dissertations, and Problem Reports (ETD)

An investigation into secondary transfer of trace DNA to evidentiary items via nitrile gloves during crime scene examination

Molly G. Younker, B.S.

The introduction of highly sensitive DNA profiling kits has led to an increase in success with samples containing sub-nanogram amounts of DNA such as touched or handled objects including doorknobs, tools, steering wheels, etc. Such trace DNA is easily transferred between individuals and objects. Studies have shown that in addition to primary transfer due to direct contact, trace DNA can also be indirectly transferred in secondary and tertiary transfer steps which do not require direct contact. Nitrile gloves …

Characterization Of Host Cell Specific Interactions During Spotted Fever Group Rickettsiae Infection, Emerson Towey

Graduate Theses, Dissertations, and Problem Reports (ETD)

Vector-borne diseases have been increasing over the past few years due to changes in climate and disturbances in the vectors’ natural environment. To mitigate the risks of these diseases, it is necessary to understand pathogen biology and how it interacts with a host to cause disease. Here we focus our attention on the tick-borne pathogen, Rickettsia rickettsii. R. rickettsii is a member of the spotted fever group (SFG) Rickettsiae and is the etiological agent of Rocky Mountain spotted fever (RMSF), a fatal human disease that is lacking an effective vaccine. Members of the bacterial genus Rickettsia are obligate intracellular endoparasites …

What A Waste: Nitrogen Runoff And Rates In The Maumee River (Ohio, Usa), Ryanne Antonette Cimatu

Browse all Theses and Dissertations

Excess anthropogenic nitrogen (N), primarily from agricultural field fertilization, causes nutrient runoff that stimulates harmful algal blooms (HABs) in western Lake Erie. As a critical tributary to Lake Erie, nutrient loading from the Maumee River drives the intensity of the annual summer HABs in the western basin. Knowledge gaps around rates of N transformations in the Maumee River currently hinder the calibration of in-river parameters in Soil and Water Assessment Tool (SWAT) models for the Maumee watershed. To address these gaps, this research quantified rates of ammonium uptake, ammonium remineralization, nitrification, and bacterial respiration alongside physicochemical parameters of the river. …

Assessing The Effectiveness Of Natural Wood Treatments Against Eastern Subterranean Termite (Reticulitermes Flavipes) Damage: A Comparative Study, Emma Goettel

Williams Honors College, Honors Research Projects

This research is to discover alternative natural chemical cues to the use of borates to deter Eastern Subterranean Termites (R. flavipes) that remain in place in areas of high moisture content. Common sources of food for Eastern Subterranean Termites include materials that are high in cellulose content. As one of these sources, wood, is an abundantly used material in society such as in home construction, research into potential methods to make this material less susceptible to termite predation is an area of public interest. The current method of deterrence is pressure treatment of wood with Borates as they disrupt the …

A Review Of Transposable Elements In Crustaceans, Alexander Salem

Williams Honors College, Honors Research Projects

This project centers around transposable elements (TEs), specifically those found in crustacean species. While transposable elements have been a growing area of interest in the scientific community for some time, the information surrounding the present state of TEs in the field of crustacean biology is limited. This project seeks to shed light on this area of study. It will focus on the relationship between TEs and crustacean evolution, and TE prevalence in crustaceans. TE studies will be categorized by these general themes as well as crustacean taxa. It will seek to answer the research question: What is known about the …

Restoration For The Small And Slimy: How Pond-Breeding Amphibians Utilize Natural, Restored, And Created Wetlands, Miranda Florent

Williams Honors College, Honors Research Projects

This research project for the Williams Honors College sought to examine how local pond-breeding amphibians utilized natural, restored, and created wetlands. Presence/absence data was gathered from field surveys, historical records, and iNaturalist data for the six study sites. It was predicted that created and restored wetlands may support less sensitive species with lower coefficient of conservatism scores, based on past surveys of a similar nature. No statistically significant results were found in this survey, but that could be due to low sample sizes and limited data sets, among other considerations. Therefore, more in-depth studies should still be undertaken to examine …

Impact Of Cannabidol (Cbd) On Daphnia Magna Heart Rate, Joanna Ross

Williams Honors College, Honors Research Projects

In 2023, Ohio legalized recreational cannabis use for adults over 21; however, research on the physiological effectsof cannabis-derived compounds, particularly cannabidiol (CBD), remains limited due to i ts narcotics classification.While CBD is known to antagonize Cannabinoid Receptor 1 (CB1), a receptor found in the cardiac tissue of a numberof organisms, the effects on cardiac activity are not fully understood. This study aimed to investigate the impact ofCBD on heart rate in Daphnia magna. The hypothesis posited that CBD would increase heart rate in Daphnia byantagonizing CB1 receptors or equivalent G-protein-coupled receptors. The subjects were exposed to threetreatments: control (dechlorinated water), …

Lung Transplant Technology, Lana Tso

Williams Honors College, Honors Research Projects

Lung disease is a significant medical problem. Numerous individuals including infants, children, and adults of all ages can all be affected. Because of this, medical research has been heavily invested in advancing technology and finding solutions for what can be the most effective way to perform lung transplants. This literature review will be focusing on what is currently known about the process of lung transplants as well as future directions for research in this area.

Research Into The Effects Of Invasive Earthworm Species, Elizabeth Gillis

Williams Honors College, Honors Research Projects

Amynthas gracilis, or Alabama jumper worms, are a species of earthworms invasive to North America that hail from Asia. These worms are known to have an effect on the levels of macro-nutrients in the soil, as well as make alterations to the structure of the soil. These changes to soil composition and structure alter the soil’s ability to retain moisture and have been shown to negatively impact European species of earthworms such as Dutch Reds (Eisenia hortensis), Red Wigglers (Eisenia fetida,) and Canadian Nightcrawlers (Lumbricus terrestris). These effects were observed and quantified by …

The Influence Of Genes On The Migratory Timing Of Great Reed Warblers, Emily Fackler

Honors Undergraduate Theses

Many organisms migrate; however, there is a lack of knowledge on the mechanisms that drive migration timing, including which genes play a role. The great reed warbler (Acrocephalus arundinaceus), a migratory bird that breeds in Eurasia and overwinters in sub-Saharan Africa, is an excellent model to study the genetics of migration. Each season, some individuals migrate early, whereas others migrate later in the season. In other words, they exhibit differences in their migratory chronotypes. Past research has identified three candidate genes (TOP1, PEAK1, and CPNE4) that influence the migratory chronotypes of another avian species, …

Screening And Analysis Of The Urobiome For The Production Of Antimicrobial Peptides To Target Uropathogenic Escherichia Coli, Jennifer Jones

Theses

Urobiome research is currently at a nascent stage, due to a previously incorrect assumption that the bladder is a sterile environment. Improvements in bacterial culturing and DNA sequencing techniques have revealed a diverse resident bacterial community within the urinary tract (urobiome). As global incidences of multidrug- resistant urinary tract infections (UTIs) continue to increase, so too does the demand for novel antimicrobial therapies. Due to its relatively understudied nature, the urobiome represents a reservoir that could be mined as a potential source of novel antimicrobial compounds (e.g., bacteriocins). The aim of this thesis was to identify urobiome bacteriocins that could …

Descriptive Study Of Adult Male Acheta Domesticus Phonotaxis, Dana Husana

Master's Theses

The phonotactic behavior of male Acheta domesticus has not been described at length. The present study evaluates the phonotactic responses of male A. domesticus in relation to age. Male crickets of different ages (young and old) were exposed to calls with attractive and non-attractive syllable periods for this species. Both age groups exhibited phonotaxis but did not show a preference towards the attractive call over the non-attractive ones. No significant relationship was found between age and phonotactic response. Additionally, no significant differences were observed between age and preferred syllable period. Acoustic responses were also observed in some of the older …

Endophytic Fungi Associated With Galls And Host Plants Of Asphondylia Borrichiae (Diptera: Cecidomyiidae), Shannon Lynn Sharpe

UNF Graduate Theses and Dissertations

Asphondylia borrichiae, like other gall-forming gnats, are obligate symbionts to the endophytic fungi (EF) they deposit when laying eggs. Asphondylia spp. and EF are important biocontrol agents, yet details surrounding their diversity, life cycles, and host interactions remain poorly understood. Galls and leaf-stem tissues from two host plants were surveyed to identify and compare EF diversity between the host tissues and species of A. borrichiae. Identification of 114 isolates was carried out by sequencing the internal transcribed spacer (ITS 1/4 primers). Pairwise alignments in multiple genetic databases were bolstered by phylogenetic analyses using maximum parsimony and maximum likelihood …

High-Quality Dietary Protein (Essential Amino Acids Matched To Reproductive Needs) Partially Breaks The Lifespan And Reproduction Trade-Off In Lubber Grasshoppers, Emma Kordek

UNF Graduate Theses and Dissertations

Finding interventions to break the trade-off between reproduction and lifespan can provide insight into physiological limitations of animals. Effects of dietary protein quality on the trade-off are currently unclear, but clarity could lead to better designed diets that match animal needs. Dietary amino acid blends matching yolk proteins support reproduction and extend lifespan in fruit flies. To test if this is conserved across species, we matched dietary amino acids to vitellogenin to test reproduction and lifespan in adult females of the lubber grasshopper. Specifically, we compared varying degrees of protein quality by manipulating dietary essential amino acids. We identified a …

Monitoring Faunal Responses To Biodegradable Oyster Reef Restoration Materials With Camera Traps, Tara L. Blanchard

Honors Undergraduate Theses

Restoration of the oyster reefs has become increasingly crucial due to great population declines around the globe. Intertidal oyster reefs provide essential foraging and loafing grounds to many faunal species, including several threatened/endangered wading bird species. Biodegradable oyster reef restoration materials have been introduced to avoid potential plastic pollution from traditional materials. Studies have shown success regarding oyster recruitment rates to these materials. However, their impacts on fauna using restored oyster reefs are unknown. This project aims to evaluate oyster reef restoration using biodegradable materials to increase faunal diversity, abundance, and foraging behaviors. Camera traps were deployed to observe fauna …

Tim/Tam Receptors: A Potential Biomarker For Predicting Sensitivity To Zika Virus-Induced Oncolysis In Non-Small Cell Lung Cancers, Shankari Somasekar

Honors Undergraduate Theses

Non-small cell lung cancers (NSCLC) constitute 80-85% of lung cancers and are the leading cause of cancer-related deaths globally. The most common cause is prolonged smoking. Current treatment options for NSCLC include surgery, radiation, chemotherapy, targeted drug therapy, and immunotherapy. Although these medications are effective in the short term, patients often face issues of drug resistance and debilitating side effects with prolonged use. Currently, the use of Zika virus (ZIKV) is being researched as a possible alternative treatment for cancer, which minimizes side effects and the risk of drug resistance. TIM/TAM proteins are identified as the putative ZIKV receptors on …

A Review Of Dielectric Barrier Discharge Cold Atmospheric Plasma For Surface Sterilization And Decontamination, Kolawole Adesina, Ta Chun Lin, Yue-Wern Huang, Marek Locmelis, Daoru Frank Han

Biological Sciences Faculty Research & Creative Works

Numerous investigations have shown that non-equilibrium discharges at atmospheric pressure, also known as "cold atmospheric plasma" (CAP) are efficient to remove biological contaminants from surfaces of a variety of materials. Recently, CAP has quickly advanced as a technique for microbial cleaning, wound healing, and cancer therapy due to the chemical and biologically active radicals it produces, known collectively as reactive oxygen and nitrogen species (RONS). This article reviews studies pertaining to one of the atmospheric plasma sources known as Dielectric Barrier Discharge (DBD) which has been widely used to treat materials with microbes for sterilization, disinfection, and decontamination purposes. To …

Bioprinting With Adipose Stem Cells And Hydrogel Modified With Bioactive Glass, Krishna C.R. Kolan, Apurv Saxena, Bradley A. Bromet, Lesa B. Steen, August T. Bindbeutel, Julie A. Semon, Delbert E. Day, Ming C. Leu

Biological Sciences Faculty Research & Creative Works

Bioprinting research is focused on utilizing growth factors and multiple cell types to create clinically relevant three-dimensional (3D) tissue models using hydrogels. Rheological and biological challenges are two main factors that limit the creation of extrudable bioactive hydrogels. In this study, we investigate incorporation of fast dissolving and bioactive borate glass in different weight to volume percentages (0.075 to 0.6%) to alginate-gelatin (1:1) hydrogel to improve rheological properties and enable bioprinting with bioactive glass. The addition of glass improved the stiffness of the hydrogel. Human adipose-derived mesenchymal stem cells (ASCs) were uniformly mixed in this bioink at 1 x 106 …

Characterizing Leaf Endophyte Composition In The Dune Grass Ammophila Breviligulata, Nabaa Majeed, Sarah Hobbs, Sarah Emery, Connor Morozumi, Natalie Christian

Undergraduate Research Events

Microorganisms living within plants play crucial roles in their health and function, yet these diverse communities that make up the plant microbiome remain poorly understood. The dune grass Ammophila breviligulata. is an ecosystem engineer which helps to build and stabilize dune ecosystems effectively acting as a buffer against storms to coastal communities. It is currently unknown whether the Ammophila microbiome plays a role in this plant species’ ability to transform dune ecosystems.. In this study, we assessed fungal diversity of endophytes—microbes living within plant tissues— in Ammophila leaves collected from Leelanau State Park, MI along the eastern shores of Lake …

The Transfer Of Male Cuticular Hydrocarbons Provides A Reliable Cue Of The Risk And Intensity Of Sperm Competition In Decorated Crickets, Clarissa M. House, Kristin Duffield, James Rapkin, Scott K. Sakaluk, John Hunt

Faculty Publications – Biological Sciences

Theoretically, males should increase their ejaculate expenditure when the probability of sperm competition occurring (or risk) is high but decrease ejaculate expenditure as the number of competing ejaculates (or intensity) increases. Here we examine whether male decorated crickets (Gryllodes sigillatus) use cuticular hydrocarbons (CHCs) transferred to females by rival males at mating to assess the risk and intensity of sperm competition and adjust their ejaculate accordingly. Unmated females and those perfumed with CHCs extracted from one, three, or five males could be distinguished chemically, providing a reliable cue of the risk and intensity of sperm competition. In agreement with theory, …

Interdisciplinary Learning: How Different Ways Of Thinking Can Fuel Passion And Expand Understanding., Allison Amy Peschek

Undergraduate Theses, Professional Papers, and Capstone Artifacts

This Capstone project was created to show the profound experience resulting from an extended range of interdisciplinary learning, and how different methods, when paired together, can enhance a learning experience. This was a personal project of exploration into those different angles, and primarily focused on avenues of logical and creating learning, respectively. These methods have been implemented by this author often in the past, but this capstone will explore this concept further, as there is a lot of potential in combining these different methods and biases in learning, to both further passion and understanding as a learner, but to also …

Investigating Calcium Levels During Excitation-Contraction Coupling In Model Huntington's Disease Skeletal Muscle, Pooneh Hajmirza Mohammadi Kamalabadi

Browse all Theses and Dissertations

One of the less studied aspects of Huntington’s disease (HD) is its impact on skeletal muscle function. Recent studies have suggested that HD patients exhibit altered muscle function and reduced muscle strength, which may be related to defects in Ca2+ handling during excitation-contraction coupling (ECC). However, the underlying mechanisms of these alterations remain poorly understood. This study aims to determine if the myoplasmic Ca2+ during ECC is reduced in late-stage R6/2 (mouse model of HD) muscle fibers compared to age-matched controls during twitch or tetanic stimulation. Such a decrease would help explain weakness or fatigue in the model HD muscle. …

Investigating The Effects Of Human Astroviruses On Aquaporins And Tight Junction Proteins In Vitro, Makalia T. Robinson

Browse all Theses and Dissertations

Human Astroviruses (HAstV) are positive sense non-enveloped single stranded RNA viruses. HAstV is divided into classical (serotype 1-8) and non-classical (HAstVMLB 1-3 and HAstV-VA1-5) astroviruses. Classical HAstV is known to cause diarrhea in children, elderly, and immunocompromised patients. Additionally, the etiology of nonclassical HAstV remains unknown. However, recent studies have implicated non-classical HAstV closely associated with immunocompromised patients diagnosed neurological diseases like acute encephalitis. The mechanisms by which HAstV cause diarrhea is currently unknown. Aquaporins (AQPs) are integral membrane proteins that regulate the movement of water and small uncharged molecules across the cell membrane in response to osmotic gradients. Tight …