Context plays an important role in shaping users’ privacy attitudes and behaviors. Users manage their personal information disclosure according to the norms of the specific context. Information sharing that is appropriate in one context may become inappropriate in another due to different norms. Such contextual information norms may vary in different national cultures. For example, users in different countries have different attitudes towards medical information sharing. Hence, as many technologies have become available around the world and users increasingly share information online with people from different countries and cultures, there is an urgent need of investigation into the concrete cultural differences in contextual information norms in the use of technologies. Such investigation is important to understand how users in different cultures manage their information privacy differently and to inform the privacy design for technologies that are used globally.

The goal of this dissertation is to understand how contextual information norms differ in different national cultures. To answer this, I conduct three cross-cultural quantitative studies. In the first study, I focus on the cross-cultural differences in contextual information norms when users share their personal information with organizations, such as governments, companies, third parties, employers, etc. Through machine learning and regression analysis on a large-scale survey data from eight countries, I model how the contextual impact differs in different national cultures. In the second and third study, I study cross-cultural differences in contextual impact in users’ interpersonal information disclosure on social network sites (SNS). The second study is about how the social context of other people sharing on SNSs (social norms) influences users’ information disclosure. The third study is about how contextual factors that characterize interpersonal relationships influence users’ privacy decisions on SNS friend requests. The findings from these three studies show that contextual information norms vary across different national cultures, especially between individualistic and collectivistic cultures. I discuss the theoretical implications based on these findings and suggest design practices on how to customize privacy support in technologies for users in different national cultures. This work contributes to multiple domains of literature including privacy, context-aware systems, cross-cultural studies and human-computer interaction.

An enzyme-mediated approach for the assembly of singly modified RNA constructs in which specific G residues are replaced with thG, an emissive isomorphic G surrogate is reported. Transcription initiation in the presence of thG and native nucleoside triphosphates enforces initiation with the unnatural analog, yielding 5’-end modified transcripts that can be mono-phosphorylated and ligated to provide longer site-specifically modified RNA constructs. To illustrate the utility of this effective approach, we explore its scope and limitations via the assembly of several altered hammerhead (HH) ribozymes and a singly modified HH substrate. By strategically modifying key positions, a mechanistic insight into the ribozyme-mediated cleavage is gained. Additionally, the emissive features of the modified nucleoside and its responsiveness to environmental changes can be used to monitor cleavage in real time by steady state fluorescence spectroscopy.

As cyclic dinucleotides’ impact on pathogenic bacteria and eukaryotic cells is gradually being recognized, shedding light on the enzymatic pathways involved in its production, degradation and recognition is of significance. Fluorescence-based techniques have been playing key roles in modern biochemical and biophysical research due to their high sensitivity and informativeness. In order to take advantage of fluorescence-based techniques, we developed isomorphic emissive cyclic dinucleotide analogs using previously developed fluorescent nucleoside analogs in the Tor lab.

Instead of going through the challenging chemical synthesis of cyclic dinucleotide analogs, we decided to exploit bacterial dinucleotide cyclases, DncV and DisA, to convert emissive nucleoside triphosphates into corresponding cyclic dinucleotides (CDNs). Rewardingly, DncV and DisA were able to synthesize emissive cyclic dinucleotides with thGTP, tzGTP, thATP and tzATP with yields comparable to that of native NTPs. Using DncV and DisA, a library of emissive CDNs were successfully synthesized.

To demonstrate the power and utility of these fluorescent CDN analogs, we sought to use them to monitor the enzyme-mediated conversion of CDNs, which is an important process in CDN signaling in cells. The quantum yields of the emissive CDNs were found to be significantly lower than that of corresponding nucleosides, which is caused by fluorescence quenching by adjacent nucleobases in the CDNs. We thus utilized the quenching effect to monitor DncV-mediated CDN synthesis with steady state fluorescence spectroscopy. By carefully analyzing the emission spectra of the reaction, we were able to derive reaction rate constants comparable to those calculated from HPLC analysis. It is a great advantage to monitor such a process with fluorescence, as traditional methods such as radioisotope labeling or HPLC cannot be used for real- time monitoring, and the experimental procedures are often time-consuming. We speculate that such a fluorescence-based method of monitoring enzymatic processes can be further optimized for high throughput screening of inhibitors for enzymes involved in CDN signaling.

In order to demonstrate the iso-functionality of the emissive CDNs, their abilities to activate the innate immune response was also studied in RAW 264.7 cells, by monitoring protein dynamics and gene expression of the cells. To our surprise, although the emissive CDNs have very close chemical structures with each other, they demonstrated very different abilities to trigger an innate immune response, which possibly indicated difference binding affinities of the analogs to STING, the cellular receptor. We believe that with careful analysis of these results, along with structural comparison of emissive CDNs, valuable insights into the signaling mechanism of CDN- STING-IFN pathway could be provided. Moreover, our results put forth new approaches for the design, preparation and implementation of new CDN analogues with altered recognition features and tuned potency and duration of the triggered cellular immune response.

This dissertation examines the production and reception of pan-ethnic identities and group relations of three Chinese migrant groups (PRC-Chinese, Taiwanese, and Hong Kongese) in Australia. In this dissertation I answer the questions why some people identify themselves as “Hua-Ren” (pan-Chinese or people with Chinese backgrounds) in some contexts, but claim they are “not Hua-Ren” in other contexts, as well as why intergroup competition/discrimination (e.g., between Chinese and white Australians) does not contribute to a broader pan-ethnic identity (like Asian-American movement in the United States). When speaking of “Chinese” or “Hua-Ren,” there seems to be little consensus. In Australia, the ambiguity of the Chinese status not only leads to complicated situations with political and cultural tensions among people from China, Taiwan, and Hong Kong, it also influences the race relations between Chinese and Australians. However, few studies have systematically examined the complex differences between national (PRC-Chinese/Taiwanese/Hong Kongese) and pan-ethnic (Hua-Ren) identities. Nor have studies discussed whether, how, and to what degree national and pan-ethnic identities become stronger or weaker in different social settings (job-finding, workplace, community, and social life), nor how they shape and transform national identities and group relations among PRC-Chinese, Taiwanese, and Hong Kongese. In other words, this dissertation explores differences in the interpretation of Hua-Ren identity within shifting contexts. I argue that pan-ethnicity is neither shaped voluntarily nor imposed by the mainstream society. Instead, it is a matter of what people subjectively interpret or believe about differences or not within shifting contexts. Pan-ethnic identity can thus become a tool of exploitation and intensification of ethnic stereotype in the cash-in-hand labor market; a strategy of managing differences and making/unmaking group boundary in the workplace; a process through which national identity is shifted to pan-ethnic identity (and vice versa) in various ethnic networks and community organizations; and a collectivity whether people adopt or reject in their everyday interactions with a non-Chinese group. In sum, this dissertation theorizes the formation and block of overseas Chinese identity, as well as what conditions favoring national or pan-ethnic identity.