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Open Access Publications from the University of California

Scholarly Works (19 results)

  • Article
Student Reports (2022)
Open space, defined as any open piece of land that is undeveloped, and is accessible to the public, may be particularly beneficial to seniors (defined as those aged 65+), who are often at high risk of social isolation and deteriorating physical and mental health. Despite documented benefits, seniors remain one of the most underserved groups in terms of physical activity and open space use, with opportunities being limited even further due to the COVID-19 pandemic. This report seeks to explore seniors’ preferences for the design of open spaces that fulfill their physical activity and other social needs in the communities of Rowland Heights and Hacienda Heights. Methods used to obtain data included surveys, site visits to major open spaces, and digital scans of online data about public park usage during the pandemic. The findings revealed open spaces in these areas being hard to navigate on foot, parks conceived as central “pandemic” meeting places, and a high demand for open spaces in neighborhoods distant from parks. The final recommendations provide ways to transform nontraditional open spaces, defined as areas not typically utilized as open spaces, such as vacant lots and parklets, using affordable and senior-friendly elements. Specifically, findings are made replicable across different neighborhoods in the East San Gabriel Valley through 6 general themes that translate into actionable constructs: Control, Safety, Access, Social Support, Biophilic Design, Active Recreation. By providing a guideline to designing open spaces in underutilized areas within a budget, the goal is that there will be greater leverage towards creating nontraditional open spaces.
    Cover page: STEPS: Spaces Through the Eyes and Perceptions of Seniors
    • Article
    Policy Briefs (2022)
      Cover page: Older Adults & Pandemic-Friendly Open Space Needs: A Post Pandemic Analysis
      • Thesis
      • Peer Reviewed
      UCLA Electronic Theses and Dissertations (2013)

      This ethnographic, sociological, and historical project explores the underrepresented diversity of experiences of elderly first-generation Korean women living in Little Tokyo Towers, and critically analyzes how gender, class, age, and homeland experience have impacted the ways that they navigate their relationships with their Japanese American neighbors, as well as within their own Korean community. Through my collection of oral histories, this project opens a window into examining an array of issues that challenge popular assumptions about the elderly, inter-ethnic relations, and community formation.

        Cover page: Elderly Korean Women in Little Tokyo Towers: Dispelling the Myth of Homogeneity
        • Article
        • Peer Reviewed
        UC Santa Barbara Previously Published Works (2020)
        Different immigrant generations may encounter distinct sexual opportunities with implications for HIV transmission. Yet, few studies have examined how immigrant generational status is associated with sexual risk behaviors among men who have sex with men (MSM). We explored relationships between immigrant generational status, social support, and sexual risk behaviors among English-speaking MSM using data from surveys conducted in Seattle, Washington, in 2014 (n = 323). We compared the sexual risk behaviors and social support of first-generation, second-generation, and third- and higher-generation MSM, and examined whether immigrant generational status and social support were associated with sexual risk behaviors using logistic regression models. Second-generation MSM reported lower friend social support than first- or third- and higher-generation MSM (p < .05). However, immigrant generational status was not associated with sexual risk behavior outcomes, even after accounting for social support. Results suggest that differences in immigration processes such as acculturation may be more predictive of risk behaviors than generational status alone.
          Cover page: Immigrant Generational Differences in Social Support and Sexual Risk Behaviors Among Men Who Have Sex With Men in Seattle, Washington.
          • Thesis
          • Peer Reviewed
          UC Merced Electronic Theses and Dissertations (2015)

          We present our study of the behavior of water at the molecular level in the presence of an external electric field. We develop two model systems using the theory of molecular dynamics (MD) and demonstrate how the tendency of interfacial water molecules to reorganize explains the structural behavior of the systems.

          Water molecules can interact with external electric fields. This interaction can be observed in various processes such as formation of raindrops in thunderclouds, lightning strikes and electrofreezing. Understanding of this interaction is relevant to variety of applications, like for example, electrospinning, electrospray ionization, crop spraying, spray painting, and inkjet printing. Furthermore, the interaction of water molecules with an external electric field plays an important role in the electroporation process.

          First, we present a novel theory of electroporation that provides insight into initiation pore formation in biological cell membranes when they are exposed to an external electric field. Using thorough structural and energetic analysis, we demonstrate that the formation of a pore is driven by the reorganization of the interfacial water molecules into energetically favorable structures.

          Second, we present our study of nano-sized water droplets placed in an external electric field. Our analysis exposes the molecular mechanism behind the nanodroplet shape change from a spheroid to a highly prolate ellipsoid. We demonstrate that a droplet extends its shape as water dipoles align with the electric field while simultaneously restructuring to minimize the dipole-related interaction energy. A new semi-empirical model is developed to predict the critical electric field value which separates the two states. We show that the new model sheds more light onto the dynamics of the system compared to previous theoretical results.

          Finally, we conclude with a possible future research work.

            Cover page: Behavior of Nanoscale Water Structures in External Electric Field
            • Article
            Research Publications, 2020-2021 (2021)
            This paper details a theoretical research proposal to explore the efficacy of theevent-related potential (ERP) component P300 as a potential biomarker in the early detection of Alzheimer’s disease. To determine P300’s efficacy as a biomarker, an electroencephalogram test, which monitors and generates data on the electrical activity of the brain via scalp electrodes, and an auditory oddball test, which aims to assess the cognitive functioning of participants, were performed. The auditory oddball test involved playing a series of tones of two different frequencies (one is the standard tone, and the other is the target tone) for participants and having participants press a button whenever they heard a target tone. Accuracy and reaction time were recorded. The aforementioned two tests depicted a strong association between P300 and the cognitive decline of patients with Alzheimer’s Disease (AD), suggesting that this ERP component may be used for the early detection of AD, which may improve the efficacy of future treatment and the overall quality of life for diagnosed patients in the long run.
              Cover page: Exploring the efficacy of P300 as a potential biomarker in detecting Alzheimer’s disease: A replication study
              • Article
              • Peer Reviewed
              Replication/Extension Papers 2021 - 2022 (2022)
              Intuitive metacognitive processes such as metaperception surprisingly have a lot moreinfluence on the intersectionality between interpersonal relations and health than one thinks. Of the many forms of metaperception, this paper aims to further explore the overblown implications effect (OIE), which is a prevalent metaperception error where one overestimates how much other people think of their successes or failures. We conducted a mixed ANOVA analysis and found further support for the statistically significant discrepancy between actors’ metaperception ratings and observers’ social perception ratings. For the extension, we continue to explore whether a longer rating duration for the actors would result in more accurate predictions of observers’ ratings compared to observers’ actual ratings by running a mixed ANOVA analysis. We hypothesized that increasing the rating duration would decrease the difference between the actors’ metaperception ratings and the observers’ social perception ratings, but our results show that there is no statistical significance between the two variables. However, it is important to note that we could not use the whole data provided due to statistical limitations. Hence, this makes it even more essential that future studies work with more representative samples to further understand the correlative factors that influence the OIE.
              • 1 supplemental PDF
              Cover page: Overblown Implications Effect: A Prevalent Metaperception Error. A Replication and Extension Study
              • Article
              • Peer Reviewed
              UC Irvine Previously Published Works (2023)
              3-methylcrotonyl-CoA carboxylase (MCC) is a biotin-dependent mitochondrial enzyme necessary for leucine catabolism in most organisms. While the crystal structure of recombinant bacterial MCC has been characterized, the structure and potential polymerization of native MCC remain elusive. Here, we discovered that native MCC from Leishmania tarentolae (LtMCC) forms filaments, and determined the structures of different filament regions at 3.4, 3.9, and 7.3 Å resolution using cryoEM. α6β6 LtMCCs assemble in a twisted-stacks architecture, manifesting as supramolecular rods up to 400 nm. Filamentous LtMCCs bind biotin non-covalently and lack coenzyme A. Filaments elongate by stacking α6β6 LtMCCs onto the exterior α-trimer of the terminal LtMCC. This stacking immobilizes the biotin carboxylase domains, sequestering the enzyme in an inactive state. Our results support a new model for LtMCC catalysis, termed the dual-swinging-domains model, and cast new light on the function of polymerization in the carboxylase superfamily and beyond.
                Cover page: Discovery, structure, and function of filamentous 3-methylcrotonyl-CoA carboxylase
                • Article
                • Peer Reviewed
                Replication/Extension Papers 2022 - 2023 (2023)
                • 1 supplemental PDF
                Cover page: Exploring the Role of Genetics in Self Control:&nbsp;A Replication and Extension Study
                • Article
                • Peer Reviewed
                UC Irvine Previously Published Works (2024)

                Background

                Hydrogen sulfide is a highly toxic, flammable, and colorless gas. Hydrogen sulfide has been identified as a potential terrorist chemical threat agent in mass-casualty events. Our previous studies showed that cobinamide, a vitamin B12 analog, effectively reverses the toxicity from hydrogen sulfide poisoning. In this study, we investigate the effectiveness of intratracheally administered cobinamide in treating a lethal dose hydrogen sulfide gas inhalation and compare its performance to saline control administration.

                Methods

                A total of 53 pathogen-free New Zealand White rabbits were used for this study. Four groups were compared: (i) received no saline solution or drug intratracheally (n = 15), (ii) slow drip saline intratracheally (n = 15), (iii) fast drip saline intratracheally (n = 15), and (iv) slow drip cobinamide intratracheally (n = 8). Blood pressure was continuously monitored, and deoxy- and oxyhemoglobin concentration changes were monitored in real-time in vivo using continuous wave near-infrared spectroscopy.

                Results

                The mean (± standard deviation) weight for all animals (n = 53) was 3.87 ± 0.10 kg. The survival rates of the slow cobinamide and the fast saline groups were 75 percent and 60 percent, respectively, while the survival rates in the slow saline and control groups were 26.7 percent and 20 percent, respectively. A log-rank (Mantel-Cox) test showed that survival in fast saline and slow cobinamide groups were significantly greater than those of no saline control and slow saline groups (P < 0.05). The slow and no saline control groups were not significantly different (P = 0.59). The slow cobinamide group did significantly better than the slow saline group (P = 0.021).

                Discussion

                The ability to use intratracheal cobinamide as an antidote to hydrogen sulfide poisoning is a novel approach to mass-casualty care. The major limitations of this study are that it was conducted in a single species at a single inhaled hydrogen sulfide concentration. Repeated investigations in other species and at varying levels of hydrogen sulfide exposure will be needed before any definitive recommendations can be made.

                Conclusions

                We demonstrated that intratracheal cobinamide and fast saline drip improved survival for hydrogen sulfide gas inhalation in rabbit models. Although further study is required, our results suggest that intratracheal administration of cobinamide and fast saline may be useful in hydrogen sulfide mass-casualty events.
                  Cover page: Intratracheal cobinamide (vitamin B12 analog) administration increases survivability in rabbits exposed to a lethal dose of inhaled hydrogen sulfideCreative Commons 'BY' version 4.0 license
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