Biology Commons^™

Are Biodiverse Communities More Resistant To Invasion? A Case Study With Marine Fouling Communities, Taylor Robert Bruntil

Cal Poly Humboldt theses and projects

The theory of biotic resistance predicts that more diverse communities should be less susceptible to invasion by novel species, but given the opposing results of multiple observational and experimental studies in marine systems, it is unclear how changes in environmental conditions can affect invasion success in communities that differ in diversity. I used marine fouling communities to test how the diversity of the species present in an initial community (hereafter termed “resident species”) affected the establishment and growth of all species not present in the initial communities (hereafter termed “novel species”) at two locations at the Eureka Public Marina, in …

Bite Force And Stress Content Of Varying Tooth Morphology And Jaw Alignment, Emily Newenhisen

Williams Honors College, Honors Research Projects

Biting is one of the primary physical actions against a food substrate involved in the process of mastication and consumption. Different shapes of solidified tissue (e.g., teeth, mandibles) are developed based on dietary preferences of the organism to improve mechanical function. Models of various geometric shapes were used to loosely replicate several common biological tooth structures. As there is little research conducted on tooth penetration force in relation to tooth shape, collection of such data was the main focus of the research. Molariform teeth found in herbivores were represented by the ball model, carnivorous needle-like teeth by cone model, cutting …

Multilevel Phenotypic Integration Of Metabolism And Behavior In House Sparrows And Mice, Tim Salzman

Theses and Dissertations--Biology

Patterns of multilevel variation in behavior, both within and among individuals, raise challenging questions about underlying mechanisms and the selective pressures acting on them. One intriguing hypothesis is that physiology shows parallel multilevel variation, and so might represent a latent trait that integrates multilevel behavioral responses. For example, foraging acquires the fuel needed to maintain metabolism, and in turn, an individual’s metabolism affects expression of foraging, and other, behaviors. Metabolism and behavior thus might coevolve to become integrated traits. Despite the appeal of this hypothesis, numerous investigations into the link between metabolism and behavior have yielded largely equivocal results.

To …

Investigating The Effects Of Disturbance And Competition On Establishment, Growth, And Reproduction Of The Endangered Ripariosida Hermaphrodita, Daniel Engelking

Theses and Dissertations (Comprehensive)

Ripariosida hermaphrodita (Virginia Mallow) is a perennial riparian plant with broad, maple-like leaves. It grows up to three meters high and is often found in large clonal patches, but sexually reproduces readily. While this plant may seem like a redoubtable competitor when growing in large colonies, it is declining across its range in North America. The only known occurrences in Canada are in southern Ontario. Prior to this study, no new populations had been recorded even though one of the known populations produces copious amounts of viable seed with potential to disperse. There are many hypotheses for its rarity, but …

Differences In Drifting Invertebrate Communities Across Arctic Ecozones And The Influence On Potential Growth Of Grayling (Thymallus Arcticus), Charles Chanyi

Theses and Dissertations (Comprehensive)

Invertebrate drift is a key process that potentially affects multiple levels of food web organization within stream environments. However, our understanding of the mechanistic drivers of drift in high latitude streams and subsequent bottom-up control that drift may have on fish predators in these environments remains understudied. This project aimed to gain the baseline knowledge of how drift functions across two major high latitude ecozones, the boreal forest and tundra, and how those possible differences in drifting community characteristics may impact drift-feeding Arctic grayling (Thymallus arcticus). These objectives were accomplished by characterizing stream environments across both ecozones, sampling …

Temperature Regulation Of Plant- Rhizobacteria Interactions Within The Soil-Rhizosphere- Rhizoplane Interface, Eric J. R. Marchetta

Theses and Dissertations (Comprehensive)

An optimal microbiome is important for plant health and can prime subsequent plant immune responses to enhance stress resilience. However, the molecular mechanisms that dynamically drive host-microbiome interactions and subsequent induced systemic resistance (ISR) responses in plants under elevated environmental temperatures remain underexplored. To address this major knowledge gap, this thesis further investigated Canadian soil-inhabiting rhizobacteria that had been previously shown to activate ISR in tomato (Solanum lycopersicum) plants. Specifically, this study characterized the in vitro physiology of these rhizobacterial strains under different temperatures, including growth, phosphate solubilization abilities and direct anti- pathogenic capabilities. Temperature-sensitivity of these parameters …

Natural Variation In Temperature-Modulated Immunity To Pseudomonas Syringae Pv. Tomato (Pst Dc3000) In Arabidopsis Thaliana Plants, Christina A. M. Rossi

Theses and Dissertations (Comprehensive)

Studies conducted on the model plant-pathogen system Arabidopsis thaliana-Pseudomonas syringae pv. tomato (Pst) showed that elevated temperature suppresses the pathogen-induced production of salicylic acid (SA), which is a key plant defence hormone. This increased host vulnerability at higher temperatures is due to downregulated expression of CALMODULIN BINDING PROTEIN 60-LIKE G (CBP60g) and SYSTEMIC ACQUIRED RESISTANCE DEFICIENT 1 (SARD1), which encode master regulators of SA production. Collectively, these previous studies only focused on one natural accession of Arabidopsis called Columbia-0 (Col-0). However, the intraspecific variation in Arabidopsis immunity phenotypes under elevated temperature remains unknown. To fill this critical knowledge gap, my …

Investigation Of The Segment Polarity Network In The Tardigrade Hypsibius Exemplaris, Taylor R. Harrison

UNF Graduate Theses and Dissertations

Segmentation has facilitated the evolution of the many forms of the panarthropods. Downstream regulation of segmentation is controlled by the highly conserved segment polarity network which includes the genes engrailed (en), hedgehog (hh), wingless (wg), cubitus interruptus (ci), patched (ptc), and smoothend (smo). While a high level of conservation has been seen in both the arthropods and onychophorans, only en has been described in any representatives of Tardigrada. Previous work had already established the loss of wg, which encodes for a Wnt ligand, in the tardigrade H. exemplaris …

Sustainability Practices In Aquaculture: Using Algae Turf Scrubber Biomass To Raise Black Soldier Flies As An Alternative Feed In Blue Tilapia, Oreochromis Aureus, Culture, Michelle C. Lowery

College of Graduate Studies: Theses & Dissertations

Since the 1980s, non-algal aquaculture has grown to encompass 49% of all seafood production in response to a growing human population and increased seafood demand (FAO, 2022). Hurdles exist to aquaculture sustainability, including dependence on wild sourced fishmeal (FM) and the impacts wastewater discharge. It takes 4-5 tons of wild forage fish to produce one ton of dry FM (Miles and Chapman, 2006) and as aquaculture is primarily conducted in earthen ponds and public open water bodies (FAO, 2022), finfish culture can have a high impact on the surrounding environment by discharging excess nutrients. This study used algae turf scrubber …

Human–Black Bear Interactions And Public Attitudinal Changes In An Urban Ordinance Zone, Mark A. Barrett, Sarah E. Barrett, David J. Telesco, Michael A. Orlando

Human–Wildlife Interactions

Human–bear (Ursus spp.) interactions (HBI) commonly occur in residential areas throughout North America. Negative HBI can be alleviated by using bear-resistant garbage cans (BRC) and by securing other bear attractants (e.g., bird feeders). Since the early 2000s, human and Florida black bear (U. americanus floridanus) densities have increased substantially throughout Florida, USA, concurrently producing an increase in HBI. In central Florida, an area with high densities of humans and black bears, we surveyed 2 neighborhoods that occurred in an urban ordinance zone established in 2016 that required residents to secure anthropogenic food sources. Residents were supplied with …

Fine Characterization Of Leafing Phenology In The Brazilian Atlantic Forest By Optical And Microwave Remote Sensing, James B. Bell

Dissertations and Theses

Tropical forests provide important ecosystem functions in the global biosphere, but they remain among the most poorly understood elements of land surface models, especially with regard to their seasonal dynamics. For instance, in seasonally dry forests, the pattern of the annual green-up in their canopies closely follows annual patterns of rainfall. The same, however, does not occur in wet forest canopies which are dominated by evergreen trees. In the latter, water is not scarce enough to limit leaf photosynthetic function. Canopy leafing phenology in these forests is therefore poorly characterized by optical remote sensing methods which are not sensitive to …

Pre-Clinical Trials With Precision-Medicine Based Therapeutics In Basal-Like Patient-Derived Xenografts, David C. Boyd

Theses and Dissertations

Breast cancer treatments have improved over time, but the diseases seeing the most benefit from these improvements have the estrogen receptor, progesterone receptor, or are positive for HER2. Basal-like breast cancer tends to not have these biomarkers, which necessitates their treatment to be traditional, untargeted therapeutics which are less effective and tend to have harsh adverse effect profiles – this is an important unmet need. These studies utilize a variety of techniques, including tissue culture, viability assays, high-throughput screening, in vivo drug treatments and imaging, pathway analyses, molecular techniques such as Western blot, antibody arrays, RNA sequencing, sc RNA sequencing, …

Host-Microbe Interactions In Non-Native Estuarine Anemones: Biogeography And Temperature, Parker K. Lund

Cal Poly Humboldt theses and projects

Non-native species are increasing in prevalence around the world, resulting in negative economic and ecological impacts. However, the broad distributions of non-native species also offer a system for investigating the response of host-associated microbial communities to environmental factors across a range of ecological scales. At the broadest scale, I investigated the geography of microbial communities in the non-native estuarine anemone Diadumene lineata on the west coast of the United States of America. Across latitudes, microbial community composition was very similar and displayed a high percentage of Klebsiella spp. at all sites. However, the communities in California tended to exhibit higher …

Temperature Regulation Of Pipecolic Acid-Mediated Plant Systemic Immunity In Arabidopsis Thaliana, Alyssa Shields

Theses and Dissertations (Comprehensive)

Significant crop losses are caused by pathogenic infections annually, which are exacerbated by increasing global temperatures due to climate change. One way by which plants respond to pathogenic attacks is through the activation of pattern-triggered immunity (PTI), effector-triggered immunity (ETI), and systemic acquired resistance (SAR), which lead to production of the central defence phytohormone salicylic acid (SA). Accompanying SA release is the putative mobilization of pipecolic acid (Pip), which acts as an immune regulatory plant metabolite that works with and independently from SA. As demonstrated in the model plant Arabidopsis thaliana following infection with the model bacterial pathogen Pseudomonas syringae …

Potential Effects Of Road Proximity On Zooplankton Communities And Water Quality In Lakes In The Northwest Territories, Marie N. Hannan

Theses and Dissertations (Comprehensive)

Studies conducted along Canada’s Dempster Highway in the Northwest Territories have shown that road dust can affect water quality in roadside lakes, leading to higher calcium, conductivity, and pH levels. These water quality changes have the potential to affect important members of the lower aquatic food web, such as zooplankton.

For my thesis research, I had two main objectives: 1) To determine if changes in water chemistry caused by deposition of road dust affects zooplankton communities; and 2) To examine if the type of roadside vegetation influences the effects of road dust on aquatic habitats. To achieve these objectives, I …

The Effect Of Alkalinity On Lampricide Effectiveness And Gill Physiology In Invasive Sea Lamprey (Petromyzon Marinus), Alexandre J. Walsh

Theses and Dissertations (Comprehensive)

The pesticides, 3-trifluoromethyl-4-nitrophenol (TFM) and niclosamide are used to control populations of invasive sea lamprey (Petromyzon marinus) in the Laurentian Great Lakes of North America. Added to streams infested with larval sea lamprey, the effectiveness of these pesticides, commonly called lampricides, are strongly influenced by water pH, with greater toxicity for both TFM and niclosamide in lower pH than higher pH water. However, the TFM and niclosamide sensitivity of sea lamprey are also greater in poorly buffered, low alkalinity water than in high alkalinity water but it is unclear why. One goal of my thesis was to propose …

Characterization Of The Clostridioides Difficile Glycosyl Hydrolase Ccsz, Brian Lowrance

Theses and Dissertations (Comprehensive)

Bacteria inhabit many of the harshest environments on Earth; persisting and thriving in conditions thought to be unsuitable for life. One common strategy to withstand these environments is the formation of a biofilm. Biofilm composition varies greatly, depending on the underlying community that produces it. Cellulose, a polymer consistently prevalent in biofilms, has been identified as a virulence factor in many pathogens and is suspected to be involved in pathogenesis by Clostridioides difficile. C. difficile is the #1 cause of hospital acquired diarrhea, which can range from mild to life-threatening infections. Biofilm formation is hypothesized to be involved in …

Winter Dynamics Of Storm Water Management Ponds And Winter Tolerance In Three Aquatic Plant Species, Patrick Strzalkowski

Theses and Dissertations (Comprehensive)

The vast majority of the research into the performance of stormwater management ponds (SWMPs) has been performed in warm regions or during the warmer seasons in temperate regions. It is presumed that SWMPs are inactive in the winter as any potential stormwater is trapped in snow and ice. The main goal of this thesis was to test this presumption and to study the dynamics and performance of three SWMPs during the winter. Remote water level loggers were installed into the three SWMPs and daily grab samples from the influents and effluents were taken and analyzed for total phosphorus (TP), chloride, …

Deep Learning-Based Technique For The Perception Of The Cervical Cancer, Aya Haraz, Hossam El-Din Moustafa, Abeer Twakol Khaleel, Ahmed H. Eltanboly

Mansoura Engineering Journal

In third-world countries, cervical cancer is the most prevalent and leading cause of death. It is affected by a variety of factors, including smoking, poor nutritional status, immunological inadequacy, and prolonged use of contraception. The Pap smear test, which is intended to prevent cervical cancer, finds preneoplastic changes in cervical epithelial cells. This study framework classified cervical cancer cells from Pap smears into five specified cell types using machine learning-based classification algorithms. The SIPaKMeD database is used in this investigation. This public dataset, which was manually cropped from 966 cluster cell images taken from Pap smear slides, has 4045 isolated …

What Kills The Virtually Immortal Palms Of The Florida Scrub?, Warren G. Abrahamson Ii

Faculty Journal Articles

Premise: Life span varies greatly across plants, with some species being capable of extreme longevity. Yet even long‐lived individuals are susceptible to climatic events, fire, and other challenges. We examined rare mortality events and their causes in two long‐lived palmettos over four decades. Methods: We monitored the survival of the clonal Serenoa repens and non‐clonal, Florida‐endemic Sabal etonia from 1981 to 2022 in four habitats along an elevational gradient within the globally imperiled Florida scrub ecosystem. We considered several challenges to palmetto survival, including extreme fires, shading due to lack of fire, droughts, periods of high precipitation, and possible pathogens. …

The Y-Chromosome's Role In Sexually Dimorphic Evolution And Mother's Curse Compensation, Tobias Nielsen

Electronic Theses and Dissertations, 2020-2023

The Y-chromosome and mitochondria (containing mtDNA) appear entirely dissimilar, the former being a sex chromosome found in the nucleus and the latter an organelle with thousands of copies in the cytoplasm. However, both experience uniparental inheritance, with Y-chromosomes being patrilineal and mitochondria matrilineal. This leads to various other similarities including haploidy, high mutation rates, and limited or lack of genetic recombination. Moreover, the low number of protein-coding genes contained on both led to the belief that neither contributes significantly to the adaptive evolution of complex traits. However, recent studies show the Y-chromosome and mitochondria both influence roughly 10% of male …

Investigating Biometrics Of Perimyotis Subflavus In Traditional And Nontraditional Hibernacula In The Southeastern United States As It Relates To Susceptibility To White-Nose Syndrome., Makayla Ferrari

Master of Science in Integrative Biology Theses

Perimyotis subflavus, or tricolored bat, populations have declined significantly since the emergence of white-nose syndrome (WNS) and has been proposed for listing as “endangered” under the United States Endangered Species Act. Traditionally, bats use caves as hibernacula, but as anthropogenic impacts have increased so has the use of manmade structures like culverts and bridges for roosting by several bat species. The internal environment of these anthropogenic structures is influenced by external temperature and humidity differently than caves and may influence P. subflavus winter activity, and thus susceptibility to WNS. One of the most significant differences in P. subflavus roosting behavior …

Characterization Of The Thermophilic Xlanase Fsa272 From Candidatus Fervidibacter Sacchari Belonging To Glycoside Hydrolase Family Gh10, Nicole Torosian, Jonathan K. Covington, Allison M. Cook, Nancy O. Nou, Jan-Fang Cheng

Undergraduate Research Symposium Posters

Candidatus Fervidibacter sacchari is a novel, facultatively anaerobic, hyperthermophilic bacterium found in terrestrial geothermal springs globally. Its genome encodes 115 putative glycoside hydrolase enzymes that are predicted to hydrolyze glycosidic bonds between carbohydrates. Fsa272, a member of the glycoside hydrolase family 10, was synthesized and cloned into Escherichia coli strain T7 Express. The transformed E. coli was grown with LB broth and ampicillin at 37°C. Fsa272 expression was induced with isopropylthio-beta-galactoside (IPTG), and the lysate was heat purified for 15 minutes at 80° C. The 3,5-dinitrosalicylic acid assay identified xylanase activity with a pH range of 4.5 to 10.5 (pHopt …

Insect Availability And Parental Care Behavior In A Common Bird, Cole Bourque

Symposium of Student Scholars

Populations of aerially insectivorous birds are declining throughout North America. Urbanization may indirectly contribute to this decline through its negative effects on populations of insects, an important food source in insectivores' diets, where low insect availability may be especially challenging for birds during breeding. How fluctuations in insect populations impact various species at higher trophic levels is an important area of current study for future conservation biology. Here, we examine whether nestling provisioning, brooding and guarding behaviors in a breeding bird—the European starling (Sturnus vulgaris)—may be altered depending on the relative insect availability in the environment. We found …

Characterization Of Caenorhabditis Elegans F07a5.4, Human Ortholog Of Olfactomedin 1, Sade K. Thomas, Karunambigai Kalichamy, Martin Hudson

Symposium of Student Scholars

Accurate control of nervous system development is critical for normal brain patterning, and defects in this process can lead to neurological disorders such as schizophrenia and Autism Spectrum Disorder. The transcription factor neurogenin is necessary for the development of neural subtypes and is deeply conserved across species. However, the transcriptional targets of neurogenin are poorly understood, creating an imperative for further study. We have used the nematode Caenorhabditis elegans as a model to better understand ngn-1/neurogenin function. Previous work from our lab revealed that ngn-1 plays a role in nerve ring architecture, and neural cell fate specification. In addition, …

Preliminary Analysis Of The Effects Of Non-Target Supplemental Feeding On Camera Trap Captures Of Small Mammals In Central Georgia, Raena Mccown, Travis Cunningham, Alfred J. Mead

Georgia Journal of Science

Supplemental bird feeding is a widespread hobby throughout western culture. Although it brings joy to many people, bird feeding has been shown to have potentially negative effects on local bird populations and small mammalian species. To study the differences in local occurrence of native small mammalian species around bird feeders and in more distant settings, six camera traps were placed in a rural residential area in Putnam County, Georgia. Three cameras were placed facing bird feeders and three placed a minimum of 60 m away from the feeders. Species presence was recorded three days a week from 12:00 am Monday …

Caribbean Reef-Building Coral-Symbiodiniaceae Network: Identifying Symbioses Critical For System Stability In A Changing Climate, Shaman Patel

All HCAS Student Capstones, Theses, and Dissertations

Increasing global ocean temperatures and frequency of marine heatwaves pose dire consequences for coral reefs. High temperatures often lead to disruptions in coral symbiosis resulting in coral bleaching, increasing the mortality of corals. However, corals can potentially avoid bleaching peril by associating with thermally tolerant symbionts. Here we provide a tool for understanding symbiosis network stability of Caribbean reef-building corals. We created a network of Caribbean hermatypic corals and their associated Symbiodiniaceae phylotypes. A bleaching model was applied to this network to test for resilience and robustness (R50) to thermal stress. It was also layered with trait data for coral …

Venomic Characterization Of A Medically Relevant Rear-Fanged Snake, Conophis Lineatus (Dipsadidae: Xenodontinae), From Middle America, Tristan Schramer

All Theses

Most traditional research on snake venoms has focused on front-fanged snake families (Viperidae, Elapidae, and Atractaspididae). However, venom is now generally accepted as being a much more broadly possessed trait within snakes, including species traditionally considered harmless. Unfortunately, due to historical inertia and methodological challenges, the toxin repertoires of non-front-fanged snake families (e.g., Colubridae, Dipsadidae, and Natricidae) have been heavily neglected despite the knowledge of numerous species capable of inflicting medically relevant envenomations. Integrating proteomic data for validation, we perform a de novo assembly and analysis of the Duvernoy’s venom gland transcriptome of the Central American Road Guarder (Dipsadidae: Xenodontinae: …

Importance Of The Microhabitat And Microclimate Conditions In The Northern Gray-Cheeked Salamander (Plethodon Montanus) Across An Elevation Gradient, Trevor Chapman

Electronic Theses and Dissertations

The southern Appalachian Mountains have among the highest salamander diversity in the world, largely due to local speciation in the family Plethodontidae. Plethodontid salamanders (i.e., lungless salamanders) are particularly sensitive to habitat climate conditions due to their reliance on cutaneous respiration, and their immediate environmental conditions (microhabitat) likely influence their dispersion and activity more than the large-scale atmospheric conditions. The Northern Gray-cheeked salamander (Plethodon montanus) is restricted to high elevations in the Appalachian Mountains. Our goal was to investigate the relationship between P. montanus and its microhabitat by examining behavioral preference for climatic conditions, characterizing the microclimate with …

Ankyrin Dependent Mitochondrial Function And Bioenergetics In The Heart, Janani Subramaniam, Janani Subramaniam

Dissertations and Theses (Open Access)

ANK2 mutations in patients are associated with numerous arrhythmias, cardiomyopathies, and other heart defects. In the heart, AnkB, the protein encoded by ANK2, clusters relevant ion channels and cell adhesion molecules in several important domains; however, its role at Mitochondria Associated ER/SR Membranes (MAMs) has yet to be investigated. MAMs are crucial to mitochondrial function and metabolism and are signaling hubs implicated in various cardiac pathologies. Among several functions, these sites mediate the direct transfer of calcium from the ER/SR to the mitochondria to modulate ATP synthesis. Given that mitochondrial function and energy production are paramount to cardiovascular heath, …