Talks

180-239
9:00-10:45

(9:00-9:15)
Movement of weaned northern elephant seal pups during their first at-sea foraging migration

Katie Saenger1★, Kate Riordan1, Molly Murphy1, Heather Harris2, Lauren Campbell2, Elizabeth Eby2, Rhys Evans3, Tim Bean1, Gita Kolluru1, Heather Liwanag1

1 Department of Biological Sciences, 2 The Marine Mammal Center, 3 Vandenberg Space Force Base, ★Speaker

The northern elephant seal (Mirounga angustirostris, NES) is a well-studied marine mammal known for engaging in long foraging migrations at sea. Adult male NES follow pathways along the coast towards Alaska and adult female NES follow pathways to open ocean. However, there is little information on weaned NES pup foraging behavior. This lack of knowledge is significant because NES have a mortality rate of >50% in the first year. This project aims to better understand the migratory movement and space use of NES during this critical life stage. We deployed satellite tags on weaned NES pups at Vandenberg Space Force Base (VSFB, est. 2016, n=15) and San Nicolas Island (SNI, est. 1949, n=10). Preliminary results show weaned pups migrate shorter distances than adults, utilize areas along the coast, and do not display sexual divergence in their migration pathways. Additionally, some weaned pups engage in multiple foraging trips in their first year, which has not previously been described in the literature. Examining these migratory pathways at this life stage and comparing them between individuals, sexes, rookeries, and years provides insight into dispersal patterns, foraging grounds, and life history, which will inform the conservation and management of this species.

(9:15-9:30)
[1]: What’s in your water? An assessment of microplastics in the seawater of the Morro Bay Estuary

Ella Leback†★§, Nikki Adams

Department of Biological Sciences, †Frost Support, §Santa Rosa Creek Foundation Support, ★Speaker

Microplastics (plastic particles < 5mm) are pervasive throughout global ecosystems, water, sediments, and aquatic and terrestrial organisms. For the past three years, the Adams lab has been measuring microplastics (MPs) in sediments and oysters of the Morro Bay Estuary. We continued our ongoing MP monitoring efforts by examining the concentrations and types of MPs (fiber, angular, or other) in seawater every two weeks at six field sites within the Estuary watershed (including a freshwater stream, Los Osos Creek). We isolated MPs from samples using filtration and digested the organic material using KOH. We stained and identified plastics using fluorescence microscopy. We hypothesized that MP prevalence would vary among sites and seasons, peaking in the back bay, where MPs may originate from terrestrial sources and accumulate due to the back bay's slower flushing time. On average, samples contained 0.01-0.13 (± 0.0007-0.022 SE) MP/mL over 11 months. Initial analysis using a two-way ANOVA of concentration and type of MPs identified slight spatial variation in MP prevalence but no significant variation among sites and collection dates. Nevertheless, the concentration of MPs varies significantly by type and sample date. The concentration of each type varied significantly from one another in the following order: other >fibers> angular (p <0.001, Tukey’s post hoc). There was also a significant interaction between the type of MPs and the sampling date (p<0.05), indicating the types of microplastics in the water column vary over time. Further analysis will explore whether there is a clear seasonal pattern in types of MPs across the Bay.

(9:30-9:45)
[3]: Analyzing stocking densities and organic line types to quantify settlement success of Nereocystis luetkeana.

Laney Hall1★§, Tatum Schneider1§, Johnny Paneno1, Kevin M. Johnson1§, Gregory Schwartz2

1 Department of Biological Sciences, 2 BRAE, §Santa Rosa Creek Foundation Support, ★Speaker

Over the last decade, kelp forests in northern California have been negatively impacted by an increased frequency of stressors. Resultantly, an overpopulation of native purple sea urchins are destructively grazing kelp forests creating extensive "urchin barrens", reducing ecosystem biodiversity. Over 96% of bull kelp forests have been lost in northern California impacting the ecological, economic, and cultural viability in the region and creating a wake of ramifications such as federal fisheries disasters. The goal of this study is to investigate the settlement patterns of bull kelp (Nereocystis luetkeana) spores on different types of organic lines (hemp, juut, and cotton), and evaluate the effects of bull kelp spore stocking densities on settlement success. Settlement success was quantified by counting juvenile sporophytes using a dissecting microscope at the end of 6 weeks. Sporophyte growth rates were measured using a compound microscope to take pictures weekly. ImageJ was used to measure both blade length and blade area to calculate growth per week. Seawater chemistry was recorded weekly using a HANNA mobile spectrophotometer, thermometer, refractometer, and pH meter. This protocol will be used for educational purposes, while the data will be shared with aquaculture farms working in both commercial and restoration aquaculture.

(9:45-10)
[4]: Exploring the Microbial Eukaryote Community in Estuarine Sediments from Morro Bay Using 18S rRNA Sequencing

Sedona Fugitt†★§, Lucy Nelson§, Nick Soares, Alexis Pasulka

Department of Biological Sciences, †Frost Support, §Santa Rosa Creek Foundation Support, ★Speaker

Morro Bay is a relatively healthy, low inflow estuary that supports diverse communities of microbial eukaryotes, which play key roles in ecosystem functioning. Studying estuarine sediments is important for understanding single celled decomposers, primary consumers, and benthic primary producers which all play important roles in the food web and in nutrient cycling. To investigate these communities, 18S rRNA sequencing was conducted on weekly sediment samples from Morro Bay throughout 2023. Our preliminary analysis focused on key groups including the Bigyra, Cryptophyta, and Ciliophora, given their potential roles in organic matter decomposition, bacterivory, and mixotrophy. Although these groups represented a relatively small proportion of the sequencing reads throughout the entire year (ranging from 0.22-3.69%), their temporal patterns - when interpreted in the context of the water column environmental conditions and microbial community composition patterns - offer insight into the structure and function of estuarine ecosystems.

(10-10:15)
[5]: Evaluating the influence of a sea otter exclusion ring in the California spiny lobster fishery: Implications for California spiny lobster catch and bycatch

Maria D.S. Lopez Neri1★§, Michael D. Harris2, Heather E.M. Liwanag1, Lisa Needles1

1 Department of Biological Sciences, 2 CDFW, §Santa Rosa Creek Foundation Support, ★Speaker

Southern sea otters (Enhydra lutris nereis) can become incidentally trapped in shellfish and finfish traps. Based on previous research, modifying the fyke opening (entrance of trap) to include a 5-inch rigid ring can prevent most southern sea otters from entering and becoming entrapped. The California spiny lobster trap fishery overlaps the range of the southern sea otter. Reducing the fyke ring size from the standard 6-to-7-inch diameter flexible opening to a 5-inch diameter, rigid metal ring can reduce or mostly eliminate incidental take of sea otters. However, there is no information on whether this rigid ring would affect the number of spiny lobsters caught, their size, and/or their weight. To investigate this, we used a paired design to fish lobster traps with standard flexible 6-to-7-inch fyke openings (n=15) and traps modified with 5-inch rigid ring fykes (n=15) just before the opening of the commercial spiny lobster fishery season. We analyzed differences between trap types for lobster catch, size and weight using a paired t-test. Results showed traps with the 5-inch exclusion ring caught significantly more lobsters, with no significant change in the size or weight of legal-size (3.25”, 83mm) lobsters. This difference appears to be driven by a higher rate of sheep crab bycatch in the standard traps compared to modified traps. These findings suggest the 5-inch exclusion ring may enhance lobster catch rates while preventing sea otters from entering traps, offering a simple, effective mitigation measure to aid in the recovery and population expansion of the southern sea otter.

(10:15-10:30)
[6]: Effects of pigmentation on response to environmental stress in Leptosiphon parviflorus (Polemoniaceae)

Magdalene Lo★, Dena Grossenbacher

Department of Biological Sciences, ★Speaker

Species experiencing environmental heterogeneity may adapt and optimize fitness to specific environments at the local scale. Adaptations within a given population may provide greater fitness in one set of environmental conditions than another, resulting in tradeoffs. One adaptation is the production of anthocyanins, a pigment that produces red, pink, and blue colors in plants and provides protection from abiotic stress, like drought and heavy metals. Leptosiphon parviflorus (variable linanthus, Polemoniaceae) is an annual wildflower in the California Floristic Province that produces plants with pink or white flowers, and these two flower morphs frequently co-occur within populations. Pink morphs have been found to be more fit on serpentine substrates than white morphs, and white morphs more fit on benign substrates than pink morphs. This project seeks to quantify the extent of abiotic selection for pigmentation through greenhouse reciprocal transplants. We anticipate that pink morphs will have patterns of greater fitness under drought and simulated serpentine soil stress than white morphs. These outcomes would suggest that pigmentation is closely tied to local adaptation and that maintenance of this pigmentation polymorphism in this species is due to abiotic factors.

(10:30-10:45)
[7]: Tick Microflora: Untapped Potential Sources of Antimicrobials

Elizabeth Norris1†★, Matt Bobbitt1, Clara McMahon2, Larisa Vredevoe1

1 Department of Biological Sciences, 2 Department of Kinesiology and Public Health, †Frost Support, ★Speaker

Antibiotic-resistant pathogens are responsible for a global public health crisis due to a shrinking arsenal of effective antibiotics and a lag in the development of novel antimicrobials as therapeutics. The microflora of insects and other arthropods provide an intriguing source of antibiotic-producing bacteria. Arthropods are known to be colonized by actinomycetes which are known to be good antibiotic producers. Ticks and other blood-feeding arthropods harbor a unique array of endosymbiotic bacteria, including their core microbiome and microbes acquired from the environment. Ixodid ticks have prolonged contact with hosts during feeding, permitting ample opportunities for exposure to host-derived microflora. Many potential microbial colonizers derived from the host may be thwarted by the core tick microbiome via competition and production of antimicrobial compounds that may target a range of host-derived bacteria due to their long co-evolutionary history making them of particular interest to combat certain human and animal pathogens. In this project, we investigated local ixodid tick species as a source of antibiotic-producing bacteria using culture-dependent methods to visualize bacterial interactions. Several species of adult ticks were collected from Poly Canyon at Cal Poly State University, San Luis Obispo. Ticks were surface sterilized and homogenized to cultivate endosymbiotic bacteria on culture media. Selective culture media was also used to encourage the growth of endosymbiotic actinomycetes. Assays were performed to detect production of antimicrobial compounds and identify isolates capable of inhibiting a range of human-associated bacterial species and surrogate species for human pathogens. Eleven tick isolates demonstrated antibiotic-producing potential. Assays were also performed to detect the production of antifungal compounds. Five isolates showed potential antifungal compound production against the tested molds and yeasts. Future steps for the project include further characterization of these isolates’ antimicrobial ability. The most promising isolates will be identified using the BIOLOG gen III microplate.

180-239
1:00-2:45

(1:00-1:15)
[8]: Patterns and thermoregulatory impacts of catastrophic molt in the northern elephant seal

Halley Carson†★§, Rachel Survilas, Heather Liwanag†§

Department of Biological Sciences, †Frost Support, §Santa Rosa Creek Foundation Support, ★Speaker

Unlike most mammals, northern elephant seals (Mirounga angustirostris) exhibit an unusual physiological phenomenon known as a “catastrophic molt,” which involves the shedding of patches of skin and fur in the process of replacing their pelage annually. Remarkably, they undergo this energetically costly process while fasting. Our project will document the timing of the molt in different age classes of northern elephant seals and will provide novel information regarding how the catastrophic molt affects thermoregulation in these large marine endotherms. To do this, we will conduct ground surveys during the annual molt at the beaches of the Piedras Blancas elephant seal colony. Because adult females and juveniles haul out for their molt at a different time than the adult males, these surveys will document the phenology of the molt according to age class. To investigate how the molt affects thermoregulation, we will take infrared thermal images of the animals at different stages of the molt. These images will quantify the surface temperature of the animals across the body, before, during, and after the catastrophic molt. In addition, we will document abiotic weather factors, including air temperature, wind, and sunlight levels, to provide context for these thermal measurements. Data were collected for adult and subadult males during the 2024 summer field season and a molt code was created in order to document the molt progression. A range of skin surface temperatures was also determined. Currently, data collection is focusing on the pup molt, which we are contrasting with the male molt and will continue to analyze during the female and juvenile molt in the upcoming spring season. This will be the first study to document the timing and thermal consequences of the catastrophic molt in northern elephant seals.

(1:15-1:30)
[9]: Polar Pelts: Morphology and Thermal Function of the Pelts of Weddell Seals

Stella Raymond†★, Dana Twisk, Allyson Taylor, Heather Liwanag

Department of Biological Sciences, †Frost Support, ★Speaker

Mammals in polar regions are subjected to energetically demanding conditions and thus face a constant challenge to thermal homeostasis. Weddell seals (Leptonychotes weddellii) are the southernmost breeding mammal on Earth and therefore face extremely cold and windy conditions from birth. Like many phocid (true seal) species, Weddell seals are born with lanugo (neonatal fur) and no substantial blubber layer. Unlike many phocid pups, however, Weddell seals begin swimming in polar waters at around two weeks of age, often before they have fully molted their lanugo. Due to the high thermal conductivity of seawater relative to air, this is thermally challenging for young pups; indeed, Weddell seal pups with lanugo exhibit higher metabolic rates in water than in air. We hypothesized that the lanugo of Weddell seals would be morphologically distinct from adult pelage, and that these differences would make lanugo pelts superior insulators in air and in water, compared to adult pelts. To test this, we compared morphological characteristics (hair length, circularity, and density) of Weddell seal lanugo (n=6) and adult pelts (n=5), and we measured the thermal function (thermal resistance) of both pelt types in air and in water. We found that lanugo hairs were longer and more circular compared to adult hairs, and lanugo pelts had a higher fur density compared to adult pelts. As expected, both pelt types had reduced thermal resistance in water compared to air. Additionally, neonate pelts had higher thermal resistance than adult pelts in both conditions. These results demonstrate the importance of the lanugo coat for thermoregulation in Weddell seal pups, while they develop their blubber layer. This has implications for how climatic changes that accelerate melting of the fast ice, where Weddell seals breed, could impact pup energetics and survival

(1:30-1:45)
[10]: Evaluation of the long-term safety of vagal and sacral nerve stimulation in Landrace pigs using neurobehavioral tests. 

Benjamin Thall★, Kyle Mahon★, Magdalena Maj

Department of Biological Sciences, ★Speaker

The vagus nerve plays a crucial role in regulating digestion by stimulating the muscles of the digestive tract to contract and relax, while an impaired vagal nerve activity is associated with poor motility, potentially leading to gastroparesis, ulcerative colitis, and chronic constipation. The goal of this project was to evaluate the long-term safety of nerve stimulation in Landrace pigs using 3 different neurobehavioral tests. Six 4-6 months-old female Landrace pigs were surgically inserted with electrodes and an implantable pulse generator (IPG) to stimulate vagus nerve (n=3 animals) or sacral nerves (n=3 animals). Vagus nerve and sacral nerve stimulation will occur at a low duty cycle (<10%) with a duration of 1hr/day for a month, compared to FDA-approved VNS/SNS therapies of 100% duty cycle for 24hr/day. Vagal nerve stimulation (VNS) and sacral nerve stimulation (SNS) is a validated method of modulating the muscle contraction rates in the stomach, colon, and pelvic floor. We have mounted a set of cameras at the swine unit and worked as a team of 10 undergraduate students to design and conduct 3 neurobehavioral tests: human approach test, novel object recognition test, and an overall animal activity. Human approach test (HAT) measures fear and anxiety of animals, and involves evaluation of the animals’ distance, body position, and head orientation in relation to a stationary researcher. Novel object recognition (NOR) test measures once a week a short-term retention memory. Activity of animals is recorded 3 times a week during a 2-hour surveillance. All recorded videos are scored using Behavioral Observation Research Interactive Software (BORIS). The neurobehavioral tests are currently ongoing and will be statistically analyzed to evaluate the effect of the surgery (pre- and post-surgery) and neuromodulation (post-surgery and during-stimulation period).

(1:45-2:00)
[12]: MicrobiomeKG: Extracting Relationships between the Microbiome and Host Health from Published Supplementary Materials

Skye Goetz1★, Gwênlyn Glusman2

1 Department of Chemistry and Biochemistry, 2 Institute For Systems Biology, ★Speaker

The microbiome represents a complex community of trillions of microorganisms residing in various body parts, and plays critical roles in maintaining host health and well-being. Understanding the interactions between microbiota and host offers valuable insights into potential strategies to promote health, including microbiome-targeted interventions. We have created MicrobiomeKG, a Knowledge Graph for microbiome research, bridging various taxa and microbial pathways with host health. This novel knowledge graph derives algorithmically-generated knowledge assertions from the supplementary tables supporting published microbiome papers. By identifying knowledge assertions from supplementary tables, and expressing them as knowledge graphs, we are casting this valuable content into a format that is ideal for hypothesis generation. We present an example use case linking helminth infections with non-alcoholic fatty-liver disease via microbial taxa. MicrobiomeKG is deployed for integrative analysis and hypothesis generation, both programmatically and via the Biomedical Data Translator ecosystem. By bridging data gaps and facilitating the discovery of new biological relationships, MicrobiomeKG will help advance personalized medicine through a deeper understanding of the microbial contributions to human health and disease mechanisms.

(2:00-2:15)
[13]: Farm evaluations of 4 lineages of the Pacific oyster Magallana gigas in California estuarine environments

Gillian Douglas★, Lexi Hollister, Skylar Wuelfing§, Shannon Baldwin, Faith Hanshaw, John Paneno, Tatum Schnider, Kristin Hardy, Kevin Johnson

Department of Biological Sciences, §Santa Rosa Creek Foundation Support, ★Speaker

As with all sectors of food production, changing environmental conditions pose a significant threat to Pacific oyster cultivation. These changing environmental conditions along with persistent disease pressures continue to have large impacts on survivorship and are driving selective breeding programs to minimize impacts to both survivorship and growth rates. In 2004, a new lineage of Pacific oysters was imported to the US West Coast from Southern Japan near the mouth of the Midori river. This new lineage has recently (since 2021) been integrated into breeding programs to increase genetic diversity and survival to pathogen stressors. Evaluating the efficacy of these breeding programs requires both on-farm and lab-based evaluations of performance across environments and abiotic conditions to reliably select for a commercially favored oyster. To better understand how each lineage performs, we monitored survivorship, growth rates, condition index, and shell shape in a multi-estuary farm study comparing commercially produced cohorts of the Midori, Miyagi, hybrid Midori and Miyagi, and triploid Pacific oyster lineages. This study was conducted in 3 oyster producing estuaries in California (Humboldt Bay, Tomales Bay, and Morro Bay) using standardized gear and monthly sampling. These findings are providing information to our farmer partners that is allowing them to make informed hatchery and planting decisions by identifying growth and survivorship traits of each lineage.

(2:15-2:30)
[14]: Compatibility of eugenol anesthesia with classroom physiology experiments on nerve and muscle of frogs

Katherine Rees†★, Jason Blank†

Department of Biological Sciences, †Frost Support, ★Speaker

Frogs serve as valuable model organisms for studying physiological responses of nerve, skeletal muscle, and heart in undergraduate biology labs. Induced hypothermia prior to pithing is the traditional method of euthanasia, but some veterinary guidelines discourage this practice and recommend chemical anesthesia instead. However, the most commonly used anesthetic, MS-222, is incompatible with physiology experiments. We sought an alternative anesthetic, and tested the hypothesis that eugenol anesthesia is compatible with classroom nerve and muscle experiments on frogs. Bullfrogs were euthanized after eugenol anesthesia or chilling. Additional groups were soaked in eugenol for extended durations of 30, 60, or 90 minutes beyond reflex loss. The sciatic nerve was stimulated while gastrocnemius force was measured using an isometric force transducer. The threshold voltage eliciting a muscle contraction and the peak isometric twitch force were recorded at 15 minute intervals for 2 hours. Isolated sciatic nerves were also evaluated to characterize anesthesia onset and recovery. Eugenol reliably induced loss of reflexes in 20 to 35 minutes. While eugenol increased threshold voltage and decreased force production, neuromuscular preparations maintained the ability to respond adequately to electrical stimulation, supporting its viability as an alternative anesthetic for classroom experiments.

180-269
9:00-10:45

(9:00-9:15)
[36]: Potential Selective Copper (I) Detection Through DNA-Binding Protein Interactions

Katrina Culman1★, Andrew Sayers2★, Steven Wilkinson2

1 Department of Biological Sciences, 2 Department of Chemistry and Biochemistry, ★Speaker

Multiple antibiotic resistance regulator (MarR) proteins are widely represented amongst bacterial and archaeal transcription factors. MarR proteins regulate a wide variety of cellular processes including efflux and degradation of toxins. MarR proteins are characterized by specific interactions with small molecules or transition metals which function to modify MarR-DNA binding thereby either attenuating or enhancing gene expression. The MarR homolog, CrmR (copper-responsive MarR) is found in Clostridioides difficile, a pathogenic bacterium that commonly causes colon infections in hospitals and long-term care facilities. Our findings demonstrate that CrmR binds at multiple sites in the promoter/operator region of an operon that includes a predicted multi-antimicrobial extrusion (MATE) protein. We also show that the CrmR-DNA binding interaction is attenuated by copper under reducing conditions which would be characteristic of the bacterial cytoplasm. Taken together, these findings suggest a novel, copper-induced stress response mechanism in C. difficile that may have important implications in the well-documented antibiotic resistance of this pathogen.

(9:15-9:30)
[37]: Therapeutics Targeting the Iron Acquisition Systems of Escherichia coli for the treatment of Urinary Tract Infections

Ian Hutt†★, Scott Eagon

Department of Chemistry and Biochemistry, †Frost Support, ★Speaker

Urinary tract infections (UTIs) are one of the most common bacterial infections caused by Uropathogenic Escherichia coli with approximately 10.5 million annual cases in the United States alone. Antibiotics have been effective at treating UTIs, but their effectiveness is waning due to the surging resistance to antibiotics in causative bacteria. If current trends continue, some researchers predict that current popular antibiotics will no longer function as effective treatment against UTIs. This problem highlights the need for new therapeutics to combat resistance. Acquisition of iron is essential to E. coli growth and survival in the urinary tract. Our goal is to prevent the uptake of iron by inhibiting the TonB protein, which is essential to E. coli in the use of transporting chelated iron into the cell. In addition, this treatment method is expected to leave beneficial E. coli strains in other regions of the body unharmed. Recently, issues with our original synthesis pathway have prompted us to design an alternative pathway. Eventually, a promising pathway involving a microwave acylation and subsequent allylic bromination was discovered. This new pathway aims to greatly cut down the work and time involved, making the formation of desired compounds much more efficient.

(9:30-9:45)
[38]: Bioinformatics Capstone: An Applied Consulting Experience in Genomics and Biotech

Madeline Bittner1★, Cooper Koenig1★, Nasreen Buhn1★, Isabella Lamont1★, Lauren Anderson1★, Christopher Dahl1★, Elisa Delgado1★, Fiona Ffrench1★, Sedona Fugitt1★, Schuyler Gooley1★, Josh Gottschalk2★, Eva Hamill3★, Lizzie Manis4★, Nikita Mittal2★, Tyler Weipert1★, Sofia Willoughby4★, Mateo Wolfe5★, Liane Wong1★, Yiu-Ming Wu5★, Jean Davidson1, Paul Anderson3

1 Department of Biological Sciences, 2 Department of Biomedical Engineering, 3 Department of Computer Science, 4 Department of Microbiology, 5 Department of Chemistry and Biochemistry, ★Speaker

The Bioinformatics Capstone serves as the integrative experience for students completing the cross-disciplinary Bioinformatics minor, drawing on coursework in biology, statistics, computer science, and data science. In this final project, students act as consultants, applying bioinformatics tools and methodologies to solve real-world challenges presented by external clients. This quarter, client partners include SeaGrant, Virgil, and QuantumCyte. The SeaGrant project focuses on analyzing genomic data from west coast Olympia oysters to develop tools for assessing the genetic relatedness between aquaculture-farmed and wild populations. This work supports conservation efforts by informing reintroduction strategies and identifying unique genomic signatures across populations. Virgil, a local biomedical startup, is developing a diagnostic platform that leverages genomic and clinical metadata to recommend personalized treatment plans for individuals with inflammatory bowel disease (IBD). Capstone students are contributing to the integration and analysis of these data sources to support precision medicine efforts. QuantumCyte, a California-based biotech company, is advancing cancer diagnostics through the fusion of AI-driven imaging and RNA sequencing technologies. Their goal is to improve detection of variant allele frequencies and gene expression patterns for more accurate and efficient cancer diagnosis. Students are helping refine bioinformatics workflows and analytical strategies to support this cutting-edge research.

(9:45-10)
[39]: Insulated Solar Electric Cooker Development

Logan Williams1†★, Eli Wortman2★, Nick Doing3★, Kyle Kojatesh4†★, Michael Albert5†★, Elena Venner4†★, David Agahjanyan6†★, Pete Schwartz6†

1 MATE, 2 ME, 3 AERO, 4 EE, 5 CE, 6 Department of Physics, †Frost Support, ★Speaker

Insulated Solar Electric Cooker Development Abstract Solid Thermal Storage (STS) plays a vital role in improving the performance of the Insulated Solar Electric Cooker (ISEC). By integrating a thermal mass beneath the cook pot, the system stores solar-generated heat for later use, enabling higher cooking power and expanding functionality beyond simple boiling and simmering. Key to effective STS design is balancing specific heat capacity with thermal conductivity to optimize energy storage and transfer. Concrete, due to its affordability, local availability, and adaptability, was evaluated as a potential STS material. Although its thermal conductivity proved insufficient for this application, the exploration led to promising use of concrete in structural components of the ISEC, supporting local, cost-effective manufacturing. To make concrete a viable structural alternative, research explored processing techniques and high strength additives to improve mechanical properties while decreasing thickness to a goal of 5 mm. The physical appearance was also researched, and studies indicate that to produce a smooth surface with a glossy sheen, the desired face should rest upon high density polyethylene during production. Further research has developed and produced a power optimizing circuit for solar panels.This circuit can be utilized to regulate the systems power throughout the varying intensities of sunlight seen throughout the day.

(10-10:15)
[40]: Examining current perceptions towards nicotine pouches among college students

Tyler Gee1★, Sharena Martin2★, Kira Schlieman1, Timothy Mai1, Katherine Santilena1, Julia Alber1, Adrienne Lent1

1 Department of Kinesiology and Public Health, 2 Interdisciplinary Studies - College of Liberal Arts, ★Speaker

Despite public health efforts to decrease use, tobacco companies continue to successfully market to younger audiences – most recently with introducing nicotine pouches in 2016. From 2019 to 2022, nicotine pouch sales increased from 126 million to 808 million. Given the newness of these products, research on perception is limited. Existing research suggests young adults and youth are more likely to use nicotine pouches than other adults. This study examined perceptions towards nicotine pouches among a sample of young adults. Intercept interviews (N=80), lasting 5-10 minutes, were conducted on a university campus in Central California between November 2024 and February 2025. Common interview themes included perceptions of harm, popular brands, social acceptance, and comparison of tobacco products. Many students viewed nicotine pouches as less risky when compared to traditional and electronic cigarettes. Some participants viewed nicotine pouches as socially acceptable, believing they do not harm those around them unlike other tobacco products (e.g., cigarettes). Interviewees, users and non-users alike, regarded nicotine pouches as a popular product. ‘Zyn’ was identified as the prominent nicotine pouch brand, with occasional references to ‘Velo.’ These findings provide insights into college students' beliefs surrounding nicotine pouches; however, more research is needed to understand young adults’ beliefs nationwide.

(10:15-10:30)
[41]: College student perceptions of on-campus medication abortion services: Preliminary findings from a qualitative study

Alexander Kappos1★, Sara Cohn1★, Ella Andersen1★, Shin Liow1, Emily Robles1†, Olivia Kaciak1, Christine Hackman1, Joni Roberts1, Kara Samaniego2

1 Department of Kinesiology and Public Health, 2 Department of Psychology and Child Development, †Frost Support, ★Speaker

Background: California Senate Bill 24 (SB24) mandates that all California public college campus health centers offer medication abortion (MAB). Understanding student perceptions of the implementation of SB24 is essential for shaping policy and public discourse, as well as increasing access to reproductive healthcare. Purpose: This study explores student perceptions and experiences related to SB24 implementation and provision of MAB services at California Polytechnic State University, San Luis Obispo. Methods: We conducted 34 qualitative interviews with Cal Poly students recruited through general education courses, snowball sampling, and the university’s secure health messaging system. Participants included both biological males and females. Interview transcripts are being analyzed using an inductive, open coding process based on thematic analysis. We aim to complete both open and axial coding to develop a qualitative codebook by Summer 2025. Results: Preliminary findings reveal a range of student perspectives, including a lack of awareness of on-campus MAB services, general support for MAB on campus, concerns about confidentiality and health outcomes, and the role of stigma in shaping attitudes and behaviors. Discussion: This research project highlights the importance of considering varied viewpoints regarding SB24. Understanding student perceptions and experiences can aid in the development of tailored outreach and education, as well as the implementation of policies that support students’ reproductive health needs.

(10:30-10:45)
[42]: Integrating heart health into home visitation: Qualitative analysis of home visitor perspectives

Elle Largent1★, Suzanne Phelan2

1 Department of Biological Sciences, 2 Department of Kinesiology and Public Health, ★Speaker

Cardiovascular disease (CVD) is the leading cause of death for women in the United States, disproportionately affecting minority and low income populations. CVD risk factors (e.g., unhealthy eating, smoking, etc.) are significant contributors to prenatal and postpartum morbidity and mortality. Throughout the country, there are evidence-based home-visiting programs in place providing interventions to pregnant and postpartum people and children; however, these often focus on supporting clients’ social wellbeing, and parenting skills, as well as facilitating community resource connection. These are all important interventions, and this study explores the possibility of enriching these interventions by understanding the perspectives of home-visiting programs on integrating CVD related content into home visitation as part of a NIH-funded implementation trial, ENRICH. Participating home-visiting programs in the study were locally based around two sister sites conducting the research, Cal Poly SLO and Brown University in Rhode Island. Interviews were conducted with home-visiting staff, and then transcripted and analyzed for key themes that would provide structure for considering what heart health intervention should look like. Barriers to intervention, as well as facilitators, were both identified and placed in context of heart health intervention. In general, home-visiting staff were receptive to the implementation of a new heart-health program and believed their clients would also be interested.

180-269
1:00-2:45

180-330
9:00-10:45

(9:00-9:15)
[29]: Kinetics of a novel dual sequential release hydrogel

Magnus Damborg†★, Sandra Ward†

Department of Chemistry and Biochemistry, †Frost Support, ★Speaker

Dual release stimuli hydrogels capable of slow and controlled release of encapsulated payloads offer various functions in many fields from agriculture to medicine. There is a large gap in knowledge on kinetic data regarding hydrogels with step-by-step kinetics and we wish to address this gap. We designed a vesicle crosslinked hydrogel for controlled stimuli responsive sequential release. Through a dynamic covalent thiol-disulfide exchange, a 4-arm thiolated polyethylene glycol (PEG) containing a silyl ether core “crosslinks” vesicles into a hydrogel. To combat this, commercially available 4-arm PEG thiol was used to create hydrogels of different PEG chain lengths and weight percentages. This commercially available compound is used to establish protocols and probe the non-responsive release kinetics. Kinetic data was collected and fitted to a variety of commonly used mathematical kinetic models allowing for new information regarding the hydrogel’s release capabilities and its future role as a drug delivery system.

(9:15-9:30)
[30]: Effect of dithiocarboxylate containing ligands on the electronic and optical properties of CuInS$_2$ quantum dots

Samantha L. Lansky†★, Riley Ramos, Isabella A. Landeros, Erin M. Drew, Varsha Chandrasekaran, Kaitlyn L. Rockwood, Parvathi Nair, Bella R. Chabot, M. Taylor Haynes II, Eric Jones, David F. Zigler

Department of Chemistry and Biochemistry, †Frost Support, ★Speaker

Quantum dots (QDs) have the ability to deliver a molecular payload to a target following photoactivation. The high toxicity of well-studied QDs, including CdSe, limits their applicability for biomedical use, while the use of less toxic QD materials, like CuInS$_2$, may be biocompatible when paired with the appropriate surface ligands. CuInS$_2$ QDs were synthesized using a one-pot method and isolated via precipitation and centrifugation. UV-Vis and fluorescence spectroscopies were used to determine the optical and electronic properties of the QDs, and dynamic light scattering was used to measure QD size. The surface ligands of CuInS$_2$ QDs were exchanged for various dithiocarboxylate containing ligands to tune the optical and electronic properties of the QDs. The fluorescence of unmodified and ligand modified QDs were compared to each other, which showed quenching of the QDs by dithiocarboxylates. In addition, the QDs catalyzed dithiocarboxylate photodecomposition. Thus, dithiocarboxylate modified CuInS$_2$ QDs show promise for the photoinduced delivery of a reducing payload.

(9:30-9:45)
[31]: Effect of Functionalized Graphene Oxide on Anticorrosion Polyurethane Coatings

Caleb Nashner★, Aaron Van Horn★, Shanju Zhang

Department of Chemistry and Biochemistry, ★Speaker

Corrosion of metal structures results in significant repair costs and safety concerns. Traditional anticorrosion methods such as anodic and cathodic protection often require expensive maintenance. Polymer coatings, particularly polyurethane (PU), offer a more cost-effective alternative with inherent barrier properties. However, the anticorrosion performance of PU can be further enhanced through the incorporation of nanofillers such as graphene oxide (GO), which also improve mechanical and thermal properties. A key challenge in GO nanocomposites is its tendency to agglomerate due to strong intermolecular interactions. This study aimed to synthesize and improve the dispersion of GO in PU coatings by functionalizing GO with mono- and difunctional isocyanates. The corrosion resistance of the resulting coatings was evaluated using electrochemical impedance spectroscopy (EIS), while mechanical properties were assessed through dynamic mechanical analysis (DMA). EIS results showed that GO incorporation significantly increased impedance at low frequencies, indicating improved barrier properties and corrosion protection. DMA revealed enhancements in both modulus and tensile strength, confirming the reinforcing effect of GO. These findings demonstrate that isocyanate-functionalized GO can be effectively dispersed in PU matrices to develop high-performance, corrosion-resistant coatings.

(9:45-10)
[32]: Heavy metal detection using low-cost portable diagnostic devices

Gabriel Ribeiro★, Andres W. Martinez†

Department of Chemistry and Biochemistry, †Frost Support, ★Speaker

Microfluidic paper-based analytical devices (MicroPADs) can be used as portable diagnostic devices to detect and measure the concentration of toxic heavy metal ions in water. The heavy metal assay relies on two sequential steps. In the first step, the water sample is incubated with $\beta$-galactosidase ($\beta$-gal), an enzyme that is inhibited by heavy metal ions even at part-per-billion (ppb) concentrations. In the second step, the incubated $\beta$-gal activity is measured by adding a yellow substrate, chlorophenol red $\beta$-galactopyranoside (CPRG), that is hydrolyzed by $\beta$-gal to a red product. Our group has developed a MicroPAD capable of automating the two steps of the assay by relying on a combination of traditional capillary action and evaporation-driven capillary action. The device includes a sample addition zone, a CPRG storage zone, an assay channel with $\beta$-gal, and an evaporation zone. Solutions of silver ion (Ag$^+$) of known concentrations ranging from 40-10,000 ppb were tested, and the degree of inhibition of the $\beta$-gal was found to correlate with the concentration of silver ion in the sample. Our current devices can detect concentrations of Ag$^+$ down to 40 ppb, but the precision of the assay is poor. This talk will describe the development of the assay and the methods we are exploring to improve the precision of the devices to ensure the MicroPADs can deliver accurate, precise, and consistent results. Low-cost MicroPADs that can detect Ag$^+$ and other heavy metal ions could have potential future applications in food and water testing.

(10-10:15)
[33]: Studying the photochemistry of dithiocarboxylates in aerated solutions

Riya Nigudkar†★, Karalee Webb†, Elizabeth Manis†, Kelsey Blechen†, Reiden Emery†, Julia Mcdonald, David Zigler†, M. Taylor Haynes†

Department of Chemistry and Biochemistry, †Frost Support, ★Speaker

Among thiocarbonyls, dithiocarboxylate chromophores have been studied in metal coordination and electrochemistry. Recent work from our group established that organic soluble dithiocarboxylate salts have a higher density of excited electronic states than their thiocarbonyl analogs. As a result, we continued our investigation into the photochemical decomposition of dithiocarboxylates in aerated solutions. Experiments testing the effects of concentration and substituents have narrowed our understanding of possible excited state relaxation pathways. Using quantum yields measured from UV-Vis data, a major photoproduct was identified and then characterized with $^{13}$C-NMR, IR, and LC-MS. Additionally, mass spectrometry provided evidence for the production of at least one intermediate. Evidence collected from both experiments thus far suggests that a photo-redox pathway is followed during the photodecomposition.

(10:15-10:30)
[34]: Investigating the Electronics of the Fragmentation of Ylidenenorbornadienes

Danilo Alamillo†★, Dan Bercovici†

Department of Chemistry and Biochemistry, †Frost Support, ★Speaker

Our method of “click-and-clip” chemistry is exemplified in the synthesis and then fragmentation of Ylidenenorbornadiene (YND) systems. A YND substrate prepared from 6,6’-dimethylfulvene and DMAD was reacted with a set of 4-substituted thiophenols, to yield a mixture of three diastereomers.? These diastereomers after chromatographic separation were characterized and identified. Hammett studies investigated the electronic effects of the retro-[4+2] fragmentations typical of YND-thiol adducts. The goal of this research is to explain the electronic effects of a range of substituents attached to the pendant aryl rings of the thiol nucleophile on the rates of retro-[4+2] fragmentation of YND-thiol adducts. A dual substituent parameter (DSP) method was utilized to examine the effects of aryl substituents and evaluate the influence of field effects versus resonance. Electron-withdrawing groups on the thiophenol stabilize the partial negative charge buildup associated with carbon alpha to the sulfur and accelerate fragmentation.

(10:30-10:45)
[35]: Linear Free-Energy Relationships of Nucleophile-Induced retro-[4+2] Cycloaddition Fragmentations of Ylidenenorbornadienes

Ashley Freeman★, Daniel Bercovici

Department of Chemistry and Biochemistry, ★Speaker

“Click” and “Clip” reactions have become new and exciting fields of research within the study of Chemistry. With the simple addition or simple cleavage of two molecules, substrates can be easily connected or removed. Our method of “click-and-clip” chemistry is exemplified in the synthesis and then fragmentation of Ylidenenorbornadiene (YND) systems. YND substrates with pendant aryl substituents have been synthesized by [4+2] cycloaddition reactions between 6,6’-diarylfulvenes and dimethylacetylene dicarboxylate (DMAD). Subsequent conjugate addition with propanethiol as a nucleophile leads to a mixture of four diastereomers. These diastereomers after chromatographic separation were characterized and identified by NOESY correlations. The goal of this research is to explain the electronic effects of a range of substituents attached to the pendant aryl rings on the ylidene bridge of the YND on the rates of retro-[4+2] fragmentation of YND-propanethiol adducts. It was observed that electron-donating groups on the aryl rings attached to the ylidene bridge stabilize the buildup of partial positive-charge on the bridgehead carbon and accelerate fragmentation.

180-330
1:00-2:45

180-237
9:00-10:45

180-237
1:00-2:45

(1:00-1:15)
[22]: Clearance Rate Comparison Between Three Lineages of the Pacific Oyster

Lexi Hollister★§, Gillian Douglas, Griffin Sawyer§, Faith Hanshaw, Kristin Hardy, Kevin Johnson

Department of Biological Sciences, §Santa Rosa Creek Foundation Support, ★Speaker

The Pacific oyster (Crassostrea gigas) is a prominent global aquaculture species whose growth may be determined by feeding rate. A new population of Pacific oysters (Midori) from Southern Japan from the mouth of the Midori river, has been introduced into breeding programs to increase disease tolerance of the highly selected Miyagi population. Previous work has found differences in growth and survival of these lineages when reared on commercial farms in Tomales Bay and Morro Bay, CA. In this study, we compared the clearance rates across multiple trials of Midori and Miyagi lineages of the Pacific oyster as well as a Hybrid cross lineage of the two populations. For each trial, to measure clearance rate, oysters were acclimated in beakers for one day and then fed Reed Mariculture LPB Shellfish Diet and the cell density of each beaker was measured over time using spectrophotometry. Clearance rates were then calculated based on the number of algae cells consumed per minute per gram of dry oyster tissue. These data provide insights into differences in feeding efficiency between lineages and are used to better understand differences in growth and survival of the three lineages observed from on-farm trials.

(1:15-1:30)
[23]: Short-term aquatic heat wave conditions alter estrogen signaling to impair oogenesis in the Amargosa Pupfish

Isabel Villafuerte★§, Sean Lema

Department of Biological Sciences, §Santa Rosa Creek Foundation Support, ★Speaker

The increasing frequency and severity of aquatic heat wave events associated with climate change may pose a threat to fish reproduction. Extremely high temperatures have been shown to impair reproductive processes in many fish taxa, yet most studies to date have exposed fish either to a stable elevated thermal regime or to prolonged periods of elevated temperatures. These thermal regimes may not always represent the fluctuating temperature conditions that fish experience in their dynamic environments. Here, we examined how a simulated short-term aquatic heat wave impacted reproductive physiology in the eurythermal Amargosa Pupfish Cyprinodon nevadensis amargosae. Adult pupfish were acclimated in mixed sex groups to an ecologically relevant fluctuating temperature regime that cycled 11°C daily, from a morning low of 20-21°C to an afternoon high of 31-32°C. After 54 d of acclimation to these fluctuating thermal conditions, a subset of the fish was exposed to a simulated ‘heat wave’ for 6 d by elevating maximum and minimum daily temperatures by 6°C. Females exposed to the short-term heat wave had significantly reduced ovarian gonadosomatic index (GSI) values and lower blood plasma concentrations of 17?-estradiol (E2), a hormone that plays a key role in regulating egg development. Male pupfish, however, were not impacted by ‘heat wave’ conditions as shown by the invariable testicular GSI values. Overall, our data reveal that short-term exposure to elevated temperatures like those during a heat wave can alter the ovarian status and reproductive endocrinology of female pupfish.

(1:30-1:45)
[24]: Development of apneustic breathing in northern elephant seal pups (Mirounga angustirostris)

Olivia Springer★§, Elise Fiskum, Molly Murphy, Heather Liwanag, Linnea Pearson

Department of Biological Sciences, §Santa Rosa Creek Foundation Support, ★Speaker

The ability to perform prolonged apnea (breath hold) is a key adaptation in diving mammals. Pinnipeds (seals, sea lions, walruses) are known to practice apnea on land and while diving. The ability to extend breath hold duration tends to increase with ontogeny in pinnipeds, though previous research has reported opposite patterns during the dependent pup life stage for northern elephant seals (Mirounga angustirostris). We examined the development of apneustic breathing in northern elephant seals, a deep-diving species, throughout pups’ approximately 4-week nursing period and after they weaned from their mothers. We hypothesized that age would influence the development of apneustic breathing. Based on previous research, we predicted (1) that younger northern elephant seal pups would exhibit apnea more frequently and for longer durations compared to older dependent pups, and (2) that apnea length would increase again after weaning. To test this, we characterized respiratory patterns of northern elephant seal pups (n = 101) using weekly video footage of known-age pups resting on the beach from 1 week of age and through the weaning period. We quantified eupneic (i.e., normal) respiration rate (breaths/min), presence/absence of apneustic breathing, and apneustic interval (length of breath hold) for each recording. We found that many pups were able to perform apnea almost immediately after birth, and that apneustic length was significantly positively correlated with age. These results contrast with previous studies in this species, as older dependent pups in our study exhibited longer apneustic intervals compared to newborn pups. This indicates that apneustic development may increase throughout ontogeny for northern elephant seal pups, which aligns with patterns observed in other pinniped species. Additional research is needed to determine whether this pattern is true for other populations of northern elephant seals or for other deep-diving seal species.

(1:45-2:00)
[25]: Harbor seal haulout behavior in and near Morro Bay

Claire Savage†★, Dr. Heather Liwanag

Department of Biological Sciences, †Frost Support, ★Speaker

Harbor seals (Phoca vitulina) are coastal marine mammals that haul out close to areas of human activity, but they are notoriously reactive to human disturbance. Plans for a wind farm offshore of Morro Bay are likely to increase ship traffic and other human activity in the Morro Bay area. The goal of this project is to generate baseline data of harbor seal haulout patterns and abundance, prior to wind farm implementation. During the summer, we documented the location and timing of harbor seal haulout behavior in Morro Bay and surrounding areas to determine haulout patterns relative to abiotic factors. To do this, we conducted regular ground surveys using binoculars at Estero Bluffs, Morro Bay, and Los Osos, documenting harbor seal abundance through a half tide cycle. We then correlated harbor seal haulout behavior to tide level and direction, air temperature, and wind. These data indicated that harbor seal abundance was significantly influenced by different combinations of these factors at each site. During the academic year, we conducted standardized surveys each week at peak haulout conditions for each location, to generate baseline data for harbor seal abundance at each site. This information will ultimately help us understand the impacts of increased anthropogenic activity associated with the offshore wind farm on our local harbor seals.

(2:00-2:15)
[26]: Leveraging long-term demographic data to detect and examine density dependence in North American songbirds

Jordan Langley†★, Clinton Francis†, Sarah Jennings†

Department of Biological Sciences, †Frost Support, ★Speaker

Although density dependence is widely accepted amongst ecologists as a fundamental process that regulates the size of natural populations, it is challenging to detect within real world wildlife populations without sufficiently long time series, and thus, it is rarely examined in more than one species at a time. We leveraged multigenerational demographic data compiled by the Monitoring Avian Productivity and Survival (MAPS) Program to examine evidence of density dependence in bird populations across North America. We used over 60,000 bird capture records from 381 MAPS banding stations that have operated between 10 and 27 years to obtain a dataset for 56 bird species. For each species, we investigated the relationship between adult abundance and per-capita productivity, a measure of reproductive output, using hurdle log-normal models within a Bayesian framework with weakly informative priors. All 56 species exhibited a negative relationship between adult abundance and per-capita productivity; however, the population size reached before negative density dependent regulation was detected, as well as the intensity of the effect, varied considerably across species. We then implemented phylogenetically-informed Bayesian models to explore how four classes of ecological traits – life history, diet, morphometric, and sexual selection traits – explained variation in density-dependent population regulation across 56 species of North American birds.

(2:15-2:30)
[27]: Beach Hopping or Beach Bound? The Pursuit of the Perfect Spot in Northern Elephant Seal Maternity

Mackenzie Davidson1★§, Allison Theobold2, Tim Bean1, Heather Liwanag1

1 Department of Biological Sciences, 2 Department of Statistics, §Santa Rosa Creek Foundation Support, ★Speaker

Polygynous breeding, in which a single male mates with multiple females , is the most common mating system among mammals and often results in variable levels of reproductive success for males. The monopolization of access to females restricts female choice, which is especially evident in the northern elephant seal (Mirounga angustirostris). Our study measured female beach choice , a decision made prior to breeding, to discern if females attempt to maximize reproductive success in this way. Over two breeding seasons (2023-2025), we marked and visually tracked 121 female northern elephant seals’ beach locations at the Piedras Blancas colony in San Simeon, CA. We combined seal observations with beach density to evaluate whether crowded beaches influenced beach choice and the likelihood of switching beaches. Using a logistical regression, we found that higher densities at the arrival beach significantly increased females’ chance of switching beaches (B = 1.57, SE = 0.81, z = 1.96, p = 0.05), while the density of the beach to which they switched was less significant (B = 1.29, SE = 0.72, z = 1.79, p = 0.07). The interaction between the first and second beach densities was highly significant and negative (B = -2.63, SE = 0.97, z = -2.70, p = 0.007), meaning that when both beach locations’ densities were high, seals were less likely to switch. We conclude that density is an important metric in determining female beach choice in northern elephant seals and is a conceivable way in which they can increase their reproductive success, an important parameter to understand in this protected species.

(2:30-2:45)
[28]: Effects of Temperature and Oxygen Exposure on Survival and Physiology of Olympia Oysters

Buyanzaya BuyanUrt†★§, Lexi Hollister†, Kristin M. Hardy, Kevin M. Johnson

Department of Biological Sciences, †Frost Support, §Santa Rosa Creek Foundation Support, ★Speaker

Olympia oysters (Ostrea lurida) are the only oyster species native to the North American West Coast. As sessile invertebrates that inhabit estuaries along the Western coast, Olympia oysters are subject to frequent and intense environmental stressors, particularly marine heatwaves and hypoxia events. In this study, we evaluated how two different populations of Olympia oysters respond to elevated temperature and oxygen limitation stress. Our physiological evaluation of the stress resilience of O. lurida included an assessment of survival rates, enzyme indicators of metabolic shifts [PK:PEPCK activity], and oxidative stress response [total antioxidant activity]. We found that survival during combined elevated temperature and anoxia stress was much greater in the more southern Morro Bay oyster population (LT50 = 28.5d) as compared to those from Elkhorn Slough (LT50 = 18.5d). Furthermore, metabolic enzyme assays found that there was a significant effect of oyster population on the PK:PEPCK ratio and a marginally non-significant interactive effect of temperature and oxygen treatment. Finally, the total antioxidant activity assay revealed no significant effects of population, temperature, or oxygen; however, the meat weight of the oyster was a significant predictor of total antioxidant activity. Collectively, our results suggest that O. lurida populations display distinct physiological responses to combined temperature and oxygen stress. The drivers of these differences may not be inherently due to population differences, as individual meat weight was a major contributor to the differences in physiological responses and covaried with population.

180-270
9:00-10:45

180-270
1:00-2:45

(1:00-1:15)
[15]: Coastal Marine Heatwaves Inside and Outside of an Upwelling Bay

Isabelle Cobb★, Ryan Walter

Department of Physics, ★Speaker

The frequency, intensity, and duration of marine heatwaves (MHWs) have increased over the last several decades, impacting the health of marine ecosystems. MHW characterization in shallow coastal environments remains a challenge due to the lack of long term in-situ measurements and satellite biases near the coastline. In coastal upwelling systems, shallow embayments (upwelling bays) may be particularly susceptible to MHWs due to their retentive nature and could act as sentinel systems for adjacent coastal environments in a warming planet. In this study, we take advantage of nearly two decades of temperature data from inside (using an automated vertical profiling instrument) and outside (using a single-depth mooring) of San Luis Obispo Bay to examine MHW patterns between the two sites. We report MHW metrics across seasonal time scales and compare differences in individuals events across depths, including the effects of coastal upwelling variability. Additionally, we compare upwelling conditions during the initiation and termination of MHWs at both sites. Our results indicate that seasonal temperature climatologies are consistently higher inside the bay, where MHW events tend to occur in greater numbers and intensities. Furthermore, while there is no distinct difference between upwelling patterns at MHW initiation between the sites, measured upwelling anomalies are statistically different for MHW termination between the sites at various depths, highlighting the important role of upwelling forcing in this region. These findings show that small-scale processes can modify MHW risk over small distances in shallow coastal environments, which could lead to improved forecasting and management of valuable coastal resources.

(1:15-1:30)
[16]: Looking For Very-High Energy Gamma-Rays From a Seyfert Galaxy With VERITAS

Isha Thoreson†★, Jodi Christiansen†

Department of Physics, †Frost Support, ★Speaker

The Very Energetic Radiation Imaging Telescope Array System (VERITAS), located in Tucson, Arizona, detects very-high energy gamma-rays. Our research group typically uses gamma-rays to study blazars. For this project, we have been using VERITAS to study a Seyfert galaxy that unexpectedly emits TeV photons. In this talk, I will report the result of our studies.

(1:30-1:45)
[17]: Ice Melt Plume Dynamics in a Two-Layer Stratified Tank

Jack Agnell1†★, Finn Carpenter1†, Khalid Abbed2†, Ryan Walter1†

1 Department of Physics, 2 Marine Sciences, †Frost Support, ★Speaker

Anthropogenic climate change is causing sea ice and ice sheets to melt at unprecedented rates globally. An improved understanding of the mechanisms involved in the ice melt process is essential to predicting the fate of sea ice and the potential impact on global circulation processes. Glaciers and icebergs within fjords are of keen interest because they represent a significant portion of the ice threatened by warming oceans. The Cal Poly Stratified Fluids Tank can emulate the vertical density stratification common in fjord systems, where fresh and brackish water from inland sources and ice melt sits on top of denser seawater intruding into the fjord from the ocean. We performed a series of experiments where we introduced a block of dyed ice to a two-layer vertically stratified system and compared the melt dynamics between systems with differing stratification strengths, determined by the density difference across the interface, and layer heights. We found that a smaller vertical density difference corresponds to a weaker barrier to vertical motions and a decreased melt time, while a larger vertical density difference leads to a stronger barrier, prevents mixing at the interface, and increases the melt time. However, we found that layer thicknesses have the greatest effect on the melt-time because they more directly determine the size of the convection cell formed by the melt-plume, and by extension, the amount of heat transfer at the ice-water interface. Future work will expand the parameter space to include a greater range of densities and layer height thicknesses, and create more complex systems using internal waves, surface waves, and different ice configurations.

(1:45-2:00)
[18]: Unraveling ecological hotspots using Lagrangian Coherent Structures in the central California Wind Energy Area

Luoma Corbin1†★, Rapha Coutin1†★, Andres Rocha Jayasinha1★, Mazen Idriss2, Casper Pratt2, Leah Hoogstra1, Ian Robbins3, Paul Choboter1, Ryan Walter4

1 Department of Mathematics, 2 Civil and Environmental Engineering , 3 Department of Biological Sciences, 4 Department of Physics, †Frost Support, ★Speaker

Ocean surface currents are complicated structures governed by processes that operate over a broad range of space and time scales and significantly impact various biological and ecological processes. One area of present and high interest is the newly leased Wind Energy Area (WEA) off the central coast of California, which has been identified for the development of an offshore wind energy farm. Using a decade of data collected by high-frequency radar antennas along the California coast, we present the first ever characterization of surface current patterns and spatiotemporal variability in the WEA. We characterized seasonal patterns in surface current directions and magnitudes to highlight the strong influence of upwelling seasonality. We also assessed seasonal patterns of current trajectories by performing particle tracking both forwards and backwards in time from the WEA to identify the spatial extent of surface current influence. Additionally, through Finite-Time Lyapunov Exponents (FTLEs), which have previously been shown to be linked with ecological hotspots for marine mammals and fisheries, we calculated regions where adjacent fluid particles maximally separate and regions where adjacent fluid particles accumulate. The findings here are critical for environmental assessment, site characterization, and conservation efforts in the vicinity of the WEA.

(2:00-2:15)
[19]: Solving Ziggu Puzzles Using the Quaternary Gray Code

Madeleine Goertz1†★, Aaron Williams2

1 Department of Mathematics, 2 Department of Computer Science, Williams College, †Frost Support, ★Speaker

The Ziggu puzzles are a family of physical puzzles designed by Oskar van Deventer. The designs are inspired by Ziggurat, a frameless n-ary puzzle designed by Bram Cohen and Eitan Cher for the 2021 Design Competition. To solve Ziggurat, one fully disassembles the tower of identical pieces. We investigate solutions to these Ziggu puzzles, which have $p$ pieces that form $m$ mazes. We encode the state of each puzzle as an quaternary number (i.e., base $4$) with $n=m+1$ digits, where each digit gives the horizontal or vertical position in one maze. We show that the number of states on a shortest solution is $6 \cdot 2^n - 3n - 5$ (OEIS A101946). There is only one solution of this length, and it is generated from the start configuration by a simple algorithm: make the leftmost modification that doesn't undo the previous modification. Replacing "leftmost" with "rightmost" instead generates the unique longest solution that visits all $(3^{n+1} - 1)/2$ states (OEIS A003462). In this way, Ziggu puzzles can be viewed as $4$-ary, $3$-ary, or $2$-ary puzzles based on how the number of state encodings, valid states, or minimum states grow with each additional maze. To help solve the puzzle from an arbitrary configuration, we provide $O(n)$-time ranking, comparison, and successor algorithms, which give the state's position along a solution, the relative order of two states, and the next state, respectively. A preprint is available at arxiv.org/pdf/2411.19291. This work was initiated at the 2024 NSF SMALL REU at Williams College and supported by NSF Grant DMS-2241623. The speaker would also like to thank the William and Linda Frost Fund in the Bailey College of Science and Mathematics for their generous support.

(2:15-2:30)
[20]: Convex Lattice $n$-gons with $k\ge3$ Interior Points

Tri Tran★, Elli Sumera★, Dana Paquin

Department of Mathematics, ★Speaker

We study the geometry of convex lattice $n$-gons with $n$ boundary lattice points and $k\geq 3$ collinear interior lattice points. We describe a process to construct a primitive lattice triangle from an edge of a convex lattice $n$-gon, hence adding one edge in a way so that the number of boundary points increases by $1$, while the number of interior points remains unchanged. We also present the necessary conditions to construct such a primitive lattice triangle, as well as an upper bound for the number of times this is possible. Finally, we apply the previous results to fully classify the positive integers for which there exists a convex $n$-gon with $k$ collinear and non-collinear interior points.

(2:30-2:45)
[21]: Pismo Beach Sand Dynamics: A Drone Study of 2024–25 Winter Swells

Gabriel Anderson†★, Marissa Bills, Benjamin Ruttenberg

Department of Biological Sciences, †Frost Support, ★Speaker

Sandy beaches are dynamic ecosystems that undergo constant physical change, shaped by both natural forces and human impacts. Seasonal patterns typically remove sand during winter swells and restore it in the summer, but climate change is increasing the frequency and intensity of winter storms, accelerating erosion in many coastal areas. Extreme swell events paired with king tides in January 2022 and 2023 dramatically reshaped parts of Pismo Beach. To better understand patterns of sand movement, I conducted a year-long study from May 2024 to April 2025 using drone-based structure-from-motion photogrammetry at three sites across Pismo Beach. This emerging, cost-effective technology allowed me to estimate monthly changes in sand volume and elevation. The 2024–2025 winter storms were milder than previous years, which is likely why the change in the amount of sand did not seem to fluctuate greatly beyond seasonal expectations. My presentation will explore both the capabilities and limitations of the drone technology and methodology I used, and will highlight its potential for broader application in coastal monitoring and management.