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Plastic Microfibers Impact the Immune System of the Pacific Oyster
No full textMicroplastics (MPs) (plastics \u3c 5 mm in size) are widespread pollutants in marine environments and pose a threat to marine organisms through ingestion or environmental exposure. Our previous research showed that the Pacific oyster (Crassostrea gigas) from Morro Bay Estuary harbor moderate amounts of microplastics, primarily microfibers (MFs), in their gills and digestive glands. While prior studies have demonstrated that microplastics can impair oyster reproduction, growth, metabolism, and survival, the impact of MFs on the immune system of C. gigas remains unexplored. Therefore, we explored whether MFs can elicit an immune response in C. gigas. To address this, we exposed oysters to three environmentally relevant concentrations of MFs (0.0076 MF/mL, 0.015 MF/mL, 0.031 MF/mL) over two weeks. Hemolymph from the pericardial cavity and digestive gland and gill tissue samples were collected to test the hypothesis that MF ingestion would trigger immune responses. We predicted a dose-dependent increase in MF accumulation in tissues, elevated hemocyte counts, and increased lysozyme activity. Our findings confirmed that oysters ingested MFs, with significantly higher concentrations found in gills (1.3358 MFs/g wet weight ± 0.184) compared to digestive glands (0.2043 MFs/g wet weight ± 0.184) (DF = 59; F = 18.8372; p = 0.00003). MF exposure led to a significant, dose-dependent increase in total hemocyte counts in hemolymph (DF = 148; F = 18.4289; p \u3c 0.0001). However, lysozyme activity significantly decreased following MF exposure (DF = 69; F = 6.9264; p = 0.0004), with reductions observed at both the lowest and highest concentrations, but not at the intermediate level. These results indicate that C. gigas ingest MFs, which accumulate primarily in the gills, and that such exposure induces a measurable immune response, characterized by increased hemocyte production and suppressed lysozyme activity. The complexity of this immune response underscores the need for further studies to evaluate how MF exposure may affect the overall health, growth, and reproductive success of C. gigas and other marine species
Direction Finding from Aerial Platforms with Amateur Radio Arrays
Full text linkThis senior project presents the development of a communication network designed to remotely control and program a distributed digital antenna array for autonomous synchronization and calibration. The system facilitates command transmission using a custom BPSK communication protocol operating in the UHF band (430–450 MHz) and employs a two-tone waveform to extract frequency, phase, and timing offsets between array nodes. These offsets are critical for aligning received signals in preparation for digital beamforming. The array comprises four nodes: three aerial units and one ground-based control unit. Each node is built using a LimeSDR Mini 2.0, Raspberry Pi, portable battery pack, and powered USB hub. GNU Radio is used to construct and manage the BPSK and two-tone signal chains, while higher-level Python scripts implement a finite state machine to coordinate timing, control logic, and data exchange. This system represents the foundational hardware layer for a larger multi-year project focused on implementing cost-effective, software-defined digital beamforming arrays. This research not only presents a novel implementation of distributed digital arrays but also enhances target localization accuracy through the creation of a coherent and calibrated digital beamformer. The findings have the potential to significantly improve the performance of distributed arrays in critical applications such as disaster response, defense, and other scenarios where access to nodes is limited
“Aquellos Que Reputan Todos Por Españoles”: Conflicting Historical Ideologies Regarding Race in Nineteenth Century California.
No full textCalifornia has a rich and diverse history marked by various communities. From its Indigenous peoples to the significant influx of immigrants in the nineteenth and twentieth centuries, the state has embraced individuals from a wide range of cultures. However, one often-overlooked group is the gente de razón, or ‘people of reason,’ California’s earliest non- Indigenous settlers from Mexico in the eighteenth century. Many arrived for military service to assist Spanish missionaries, while others settled with their families, creating some of California’s vibrant towns. Despite being a smaller population compared to later immigrants, they left a lasting impact on place names, food, and culture. Recent research analyzing Spanish census records from the eighteenth and nineteenth centuries reveals a compelling narrative often overshadowed by romanticized views of California’s history. Notably, many gente de razón had mixed European, African, and Indigenous Mexican heritage during an era when racial hierarchies were beginning to form in Latin America and the United States. Their relative isolation in California may have shielded them from potential discrimination, but their diverse backgrounds ultimately melded into a collective identity known as the Californios. Intriguingly, after the United States gained control of California in the mid-nineteenth century, many Californios were categorized as “White” in U. S. Census records. Given the United States’ racially motivated strategies to maintain social hierarchies concerning African-descended individuals and Indigenous populations, it is notable that many Californios actively participated in government and were integrated into the expanding United States. Their wealth as landowners may have played a role in this integration, but it ultimately underscores how race is a social construct influenced by regional and contextual factors. This thesis aims to explore why the Californios were designated as such and how their historical and societal status in California shaped their identity in relation to the evolving concept of race over time
Assessment of the IMX7ULP Heterogeneous SoC for Use in a Next Generation Student CubeSat OBC
Full text linkCubeSats represent a rapidly evolving platform for space research, industry, and education, demanding increasingly sophisticated onboard computing solutions that balance performance, fault tolerance, size, weight, and power constraints. Although the design of the Cal Poly\u27s CubeSat Lab\u27s (PolySat) current On-Board Computer (OBC) keeps up with many of these factors, the demands of modern workloads like fine attitude determination will start to outpace available compute. While the selection of a more capable processor to address this would have traditionally resulted in increased energy usage, modern system-on-chip (SoC) architectures offer novel ways to trade available compute for power savings on-the-fly. With this motivation, the NXP i.MX7ULP SoC—a dual-core heterogeneous architecture featuring an ARM Cortex-A7 and Cortex-M4—is investigated for use in PolySat’s next-generation OBC. A performance and power trade study is conducted using an i.MX7ULP development kit, focusing on critical capabilities such as fault tolerance, power modes, cross-core communication, floating point arithmetic, and vectorization. The A7 and M4 cores are also individually characterized and assessed for software development ease. Results indicate that performance of this SoC can scale up to 15x that of the existing OBC while still being more energy efficient. They also showed the M4 core has the potential of reducing idle state power consumption by up to 53% of the current OBC\u27s by power-gating the other core. Additionally, worst case power consumption during intensive tasks remained under 480 mW. Cross-core communication overhead was also shown to be minimal and software development was found to be approachable using available software development kits (SDKs). The results of the investigation were applied towards starting the design of a software and hardware architecture that poises PolySat to handle the missions of today and the future
Adjoint Enhanced Panel Methods
Full text linkThis thesis describes the development, implementation, and validation of an adjoint-enhanced panel method for two-dimensional airfoil analysis. While conventional panel methods are computationally efficient for flow analysis, they typically rely on relatively computationally expensive finite differencing for gradient calculation in design optimization or sensitivity studies, a limitation addressed by employing the discrete adjoint method. The core of this work involves integrating the discrete adjoint method with a Hess-Smith panel code utilizing Class-Shape Transformation (CST) for airfoil parameterization, which requires the analytical derivation of sensitivities for panel geometry, boundary conditions, and the aerodynamic influence matrix with respect to the CST design parameters. Performance analysis highlights the significant computational efficiency advantage of the adjoint method over traditional finite differencing for gradient calculation, with superior scaling as the number of design parameters grows, even for objectives requiring finite difference evaluation of their direct sensitivities. This work successfully establishes a robust and efficient adjoint-enhanced tool for 2D airfoil analysis, providing a solid foundation for future extensions to more complex aerodynamic design and optimization problems
Evaluating Nanobubble-Enriched Water Treatments for Cleaning Stainless Steel Winery Tanks at the Gallo Winery Research Station in Livingston, California
Full text linkABSTRACT
Evaluating nanobubble-enriched water treatments for cleaning stainless steel winery tanks at the Gallo winery research station in Livingston, California.
Edgar A. Godoy-Garcia
Sanitation of stainless steel wine storage tanks is a critical component of quality control in commercial winemaking operations. Ineffective cleaning can lead to microbial contamination, product spoilage, and safety concerns. Traditionally, wineries rely on manual scrubbing, chemical cleaning agents, and extensive water rinsing cycles to maintain sanitary tank conditions. However, these methods are resource-intensive and may pose risks to both workers and the environment due to chemical exposure and wastewater generation. In response to growing industry interest in sustainable technologies, this study investigated the use of nanobubble (NB) technology as an alternative cleaning strategy for winery tanks. Nanobubbles are submicron gas cavities in aqueous solutions that exhibit unique physicochemical properties, including long-term stability, high internal pressure, and reactive radical generation upon collapse, making them attractive candidates for cleaning and sanitation applications. The research was conducted in two phases: a laboratory-scale bench experiment and a full-scale winery field trial. In the lab study, stainless steel test strips were soiled for four months with red wine lees and cleaned spraying nanobubble-enriched water generated with compressed air, oxygen (O₂), or carbon dioxide (CO₂). Cleaning efficacy was evaluated using ImageJ to analyze pre- and post-cleaning photographs. Although oxygen nanobubbles showed the greatest reductions in red and blue pixel intensities, suggesting darker post-cleaning surfaces, statistical differences among treatments were limited. Moreover, interpreting these brightness shifts proved challenging, as darker surfaces may result from pigment removal, residue oxidation, or uneven redistribution. Thus, the image analysis results were inconclusive, and reduced brightness could not be definitively linked to cleaning effectiveness. The winery-scale trial evaluated five cleaning treatments applied to 658-gallon stainless steel tanks soiled for one hour with a consistent organic load referred to as distilling material (DM). The treatments included: (1) nanobubble-enriched water with compressed air, (2) nanobubble-enriched water with CO₂, (3) a chemical oxidizing sanitizer (Sterox), (4) a manual hand-scrubbing protocol reflective of standard winery practice, and (5) a hot water rinsed untreated control. Cleaning effectiveness was quantified using adenosine triphosphate (ATP) bioluminescence measurements to assess residual microbial contamination. ATP readings demonstrated that the NB + air treatment significantly reduced surface contamination and performed comparably to both the chemical sanitizer and manual scrubbing. Overall, results from both lab and winery trials indicate that nanobubble-enriched water, particularly with air, can achieve effective cleaning performance without the use of harsh chemicals or excessive manual labor. The implementation of nanobubble technology offers a sustainable, low-impact alternative for wineries seeking to reduce chemical usage, labor intensity, and water consumption while maintaining sanitation standards. These findings contribute to the advancement of environmentally responsible cleaning practices in the food and beverage industry and lay the groundwork for broader adoption of nanobubble systems in commercial winery operations.
Keywords: winery, stainless steel, tanks, cleaning, nanobubbles, soiling, nanobubble technology, ATP bioluminescence, ImageJ analysis
From Conflict to Clarity: Resolving Differences in Habitat Assessments to Inform Conservation Priorities for the Giant Kangaroo Rat
Full text linkFrom Conflict to Clarity: Resolving Data Differences in Habitat Assessments to Inform Conservation Priorities for the Giant Kangaroo Rat
Caroline MacKenzie
Conservation strategies frequently rely on habitat suitability models, habitat assessments and species occurrence data to identify areas for protection. However, these methods often produce conflicting inference on species presence and habitat quality, complicating management decisions. This study builds on prior work which used three distinct methods to guide conservation planning for the endangered Giant Kangaroo Rat (Dipodomys ingens): habitat suitability modeling based on abiotic predictors, aerial imagery to assess habitat quality through visible burrow mounds and live-trapping data to confirm species presence. While each method captures a different aspect of habitat use, disagreements stemmed from temporal mismatches, inconsistent spatial resolution and outdated environmental inputs. Here, I use updated versions of each dataset to reassess areas of disagreement and investigate the root causes of conflict among methods. By correcting these issues, this reassessment provides clearer evidence of site persistence and suitability. I found that much of the previous misalignment between methods was driven by outdated inputs, differences in spatial scale and temporal mismatches in data availability. These findings highlight the importance of using multi-method comparisons not just to detect presence, but to understand persistence, site quality and underlying causes of misalignment.
Habitat suitability models updated with higher-resolution environmental layers from the POLARIS dataset (~30 m), as opposed to coarser-scale data from SSURGO, yielded more stable indicators of long-term habitat value than single-year trapping events. Aerial imagery was particularly effective in resolving mismatches when used with repeated surveys, confirming its value as a tool for detecting long-term site use. In cases where methods disagreed, suitability modeling was more often consistent with outcomes observed during reassessment. These findings highlight the importance of multi-method integration and underscore the need for continued investment in fine-scale—site-level, species-specific—data collection, particularly in areas of misalignment between methods, where resolving discrepancies often requires more detailed but costly survey efforts than coarse-scale regional datasets can provide. Conservation efforts grounded in current, locally validated datasets are more likely to reflect true ecological conditions and better support species recovery in rapidly changing landscapes
Simplifying the Housing Experience: A Redesign of the Cal Poly University Housing Portal
Full text linkThere are challenges in functionality, navigation and aesthetics with the current Cal Poly University Housing portal. There exists a need for a redesign of the portal to be more intuitive and user friendly for students. By conducting research with students and University Housing staff to gain a full understanding of the current issues present, an improved interface that reflects the needs of Cal Poly students can be produced. The goal of this self-guided senior project is to provide a streamlined experience that allows students to easily complete their main task with minimal effort. This paper outlines the redesign process of the Cal Poly University Housing portal over a 10-week period. The final deliverable of this project is a new website prototype that addresses crucial aspects of usability such as navigation, content organization, and feedback to give students more control over their housing needs and eliminate the current overwhelming nature of the process
Mustang Living: A Guide to Student Housing
Full text linkIt is not an easy transition for college students to go from living in a place they have called home, to struggling to secure a reliable and affordable home as a college student who moved away from home for the first time. This significant milestone should be a task that is rewarding and exciting, rather than life-altering and stressful. When envisioning a way to heal the chaos of house searching in San Luis Obispo, Mustang Living would be a dedicated section of Mustang News, available in both print and digital formats, designed to serve as a comprehensive resource for students navigating housing options. The purpose of “Mustang Living” is to provide guidance. This is crucial in resolving the lack of understanding and advice for tenant rights and rental issues. The final project will be presented through research-based articles, student testimonials, expert insights, and practical tools to enhance the student housing experience
