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Open Access Publications from the University of California

Scholarly Works (7 results)

  • Multimedia
  • Peer Reviewed
CMPM 80K (2020)
Far Dock by Wang Liao You are a wanderer looking for supplies to survive. This world was destroyed by a war which began in nearly a thousand years ago. Even though the war was over, the space weapon, called "aurora", still founctions. Aurora is a space weapon which uses beam to destroy its target, but even the war is over, it still destroy people's buildings. Due to aurora, it's hard for people to survive. In your journey, you will meet a scientist who has slept for hundreds years or meet your old friend Nozomi. You will find out the way to stop aurora with your partner or you can choose to live with Nozomi in this cruel world.
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Creative Commons 'BY-NC' version 4.0 license
  • Thesis
  • Peer Reviewed
UC Davis Electronic Theses and Dissertations (2023)

This dissertation aimed to address two important issues in the current research on context collapse on social media. The first issue pertains to the oversimplification of the concept, resulting from a primary focus on the structural aspects of context collapse. In order to provide a more comprehensive understanding, this dissertation adopts the perspective of technological affordances, emphasizing the need to consider both the structural and experiential aspects in the context collapse literature. The second issue involves the predominant emphasis on the effects of context collapse on individual-level factors, such as self-presentation, while neglecting its potential social and political implications. To tackle these issues, this dissertation presents two empirical studies. Study 1 focuses on the relatively less discussed experiential aspects of context collapse and is dedicated to the development and validation of a measurement, encompassing six dimensions of its experiential aspects. Through multiple iterations of confirmatory factor analyses, the measures were developed, refined, and validated in relation to a variety of theoretically relevant variables. In addition, three different datasets were utilized to test the measurement invariance, and a partial weak invariance for the measurement model was achieved. Study 2 aims to shed light on the social implications of context collapse beyond the individual level by focusing on the psychological phenomenon of false consensus. False consensus refers to the widespread tendency of individuals to overestimate the commonness and appropriateness of their own beliefs, attitudes, or behaviors. This phenomenon is inherently relevant to the perceptions of public opinion and the biases individuals hold regarding them. In this study, the relationships between both the structural and experiential aspects of context collapse and false consensus were examined. Multiple regression analyses were conducted to investigate the associations between these variables. However, the results did not provide any significant evidence to suggest a significant relationship between the two. Although the study did not find a significant association between context collapse and false consensus, it contributes to our understanding by exploring the potential linkages between these constructs. Further research with refined methods can be used to detect the potential associations between context collapse and false consensus.

    Cover page: Context Collapse on Social Media and False Consensus
    • Thesis
    • Peer Reviewed
    UC Davis Electronic Theses and Dissertations (2022)

    Adopting the framework of social exchange in researching supportive communication, this work proposes the concept of support exchange. This dissertation defines support exchange and discusses how support exchange is similar to and different from instrumental exchange, which has been the main topic the previous social exchange research. Based on the discussion, the propositions on the relationship between exchange structure and social solidarity in support exchange are established. The propositions were tested through a controlled small-group lab experiment with a 2 (exchange structure: direct reciprocal exchange vs. generalized exchange) x 2 (support type: emotional vs. informational support) design. 285 participants embedded in 95 triads interacted in an online support group following the instructions. Findings from the experiment and the linguistic analysis of the interaction data show that direct reciprocal support exchange generates stronger social solidarity, perceived supportiveness, and commitment to the online group than generalized support exchange does. Limitations and implications of the findings are discussed.

      Cover page: Social Support as Social Exchange: Exchange Structure and Social Solidarity in Online Support Groups
      • Article
      • Peer Reviewed
      UC Davis Previously Published Works (2024)
      BACKGROUND: This study examined national similarities and differences in peoples engagement in health preventive behaviors during a public health crisis, as well as investigated the underlying individual-level psychological mechanisms. A conceptual distinction was made between self-focused and other-involved preventive behaviors in response to public health crises. METHOD: Two cross-sectional surveys were conducted in the United States (N = 888) and China (N = 844) during the early stage of the COVID-19 pandemic. Hayes PROCESS was utilized to assess national differences in seven preventive behaviors, along with the mediating effects of self-construal and health locus of control. RESULTS: The results showed that American participants reported greater engagement in self-focused preventive behaviors than Chinese, whereas Chinese participants reported greater engagement in other-involved preventive behaviors than Americans. Chinese participants also engaged more in other-involved than self-focused preventive behaviors. Self-construal and health locus of control partially explained the observed differences in engagement in preventive behaviors. DISCUSSION: This study introduces a culture-sensitive approach to provide insights for crafting communication interventions that can enhance the effectiveness of health campaigns in the context of a public health crisis.
        Cover page: Explaining differences in self-focused and other-involved public health preventive behaviors between the US and China: the role of self- construal and health locus of control.
        • Article
        • Peer Reviewed
        UC Davis Previously Published Works (2022)
        Documenting the emergent social representations of COVID-19 in public communication is necessary for critically reflecting on pandemic responses and providing guidance for global pandemic recovery policies and practices. This study documents the dynamics of changing social representations of the COVID-19 pandemic on one of the largest Chinese social media, Weibo, from December 2019 to April 2020. We draw on the social representation theory (SRT) and conceptualize topics and topic networks as a form of social representation. We analyzed a dataset of 40 million COVID-19 related posts from 9.7 million users (including the general public, opinion leaders, and organizations) using machine learning methods. We identified 12 topics and found an expansion in social representations of COVID-19 from a clinical and epidemiological perspective to a broader perspective that integrated personal illness experiences with economic and sociopolitical discourses. Discussions about COVID-19 science did not take a prominent position in the representations, suggesting a lack of effective science and risk communication. Further, we found the strongest association of social representations existed between the public and opinion leaders and the organizations' representations did not align much with the other two groups, suggesting a lack of organizations' influence in public representations of COVID-19 on social media in China.
          Cover page: Multiplicity and dynamics of social representations of the COVID-19 pandemic on Chinese social media from 2019 to 2020
          • Article
          • Peer Reviewed
          UC San Francisco Previously Published Works (2021)

          Background

          The differential diagnosis of frontotemporal dementia (FTD) and Alzheimer's disease (AD) is difficult due to the overlaps of clinical symptoms. Structural magnetic resonance imaging (sMRI) presents distinct brain atrophy and potentially helps in their differentiation. In this study, we aim at deriving a novel integrated index by leveraging the volumetric measures in brain regions with significant difference between AD and FTD and developing an MRI-based strategy for the differentiation of FTD and AD.

          Methods

          In this study, the data were acquired from three different databases, including 47 subjects with FTD, 47 subjects with AD, and 47 normal controls in the NACC database; 50 subjects with AD in the ADNI database; and 50 subjects with FTD in the FTLDNI database. The MR images of all subjects were automatically segmented, and the brain atrophy, including the AD resemblance atrophy index (AD-RAI), was quantified using AccuBrain®. A novel MRI index, named the frontotemporal dementia index (FTDI), was derived as the ratio between the weighted sum of the volumetric indexes in "FTD dominant" structures over that obtained from "AD dominant" structures. The weights and the identification of "FTD/AD dominant" structures were acquired from the statistical analysis of NACC data. The differentiation performance of FTDI was validated using independent data from ADNI and FTLDNI databases.

          Results

          AD-RAI is a proven imaging biomarker to identify AD and FTD from NC with significantly higher values (p < 0.001 and AUC = 0.88) as we reported before, while no significant difference was found between AD and FTD (p = 0.647). FTDI showed excellent accuracy in identifying FTD from AD (AUC = 0.90; SEN = 89%, SPE = 75% with threshold value = 1.08). The validation using independent data from ADNI and FTLDNI datasets also confirmed the efficacy of FTDI (AUC = 0.93; SEN = 96%, SPE = 70% with threshold value = 1.08).

          Conclusions

          Brain atrophy in AD, FTD, and normal elderly shows distinct patterns. In addition to AD-RAI that is designed to detect abnormal brain atrophy in dementia, a novel index specific to FTD is proposed and validated. By combining AD-RAI and FTDI, an MRI-based decision strategy was further proposed as a promising solution for the differential diagnosis of AD and FTD in clinical practice.
            Cover page: An MRI-based strategy for differentiation of frontotemporal dementia and Alzheimer’s disease
            • Article
            • Peer Reviewed
            UC Davis Previously Published Works (2024)
            The Farm Animal Genotype-Tissue Expression (FarmGTEx) project has been established to develop a public resource of genetic regulatory variants in livestock, which is essential for linking genetic polymorphisms to variation in phenotypes, helping fundamental biological discovery and exploitation in animal breeding and human biomedicine. Here we show results from the pilot phase of PigGTEx by processing 5,457 RNA-sequencing and 1,602 whole-genome sequencing samples passing quality control from pigs. We build a pig genotype imputation panel and associate millions of genetic variants with five types of transcriptomic phenotypes in 34 tissues. We evaluate tissue specificity of regulatory effects and elucidate molecular mechanisms of their action using multi-omics data. Leveraging this resource, we decipher regulatory mechanisms underlying 207 pig complex phenotypes and demonstrate the similarity of pigs to humans in gene expression and the genetic regulation behind complex phenotypes, supporting the importance of pigs as a human biomedical model.
              Cover page: A compendium of genetic regulatory effects across pig tissues.
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