4 results for Wang, Yi, Masters

  • Production and characterization of salivaricin MPS-like inhibitory activity from streptococcus uberis strain NY42

    Wang, Yi (2010)

    Masters thesis
    University of Otago

    Streptococcus salivarius, a predominant bacterial species found in the human oral cavity, is increasingly studied for its production of bacteriocin-like activity. Much of the interest in the study of S. salivarius is driven by the perceived potential probiotic applications. The preliminary characterization of salivaricin MPS (salMPS), a bacteriocin produced by S. salivarius strain MPS revealed a large antimicrobial molecule with specific inhibitory activity against Streptococcus pyogenes, a potential human pathogen. In the present study, the production of salivaricin MPS was evaluated from its original producer strain MPS using various growth media. Contrary to previous findings, it was almost impossible to detect any inhibitory activity when the producer was grown in liquid THB (Todd-Hewitt broth) medium, with or without supplement. The additional inhibitory activity of strain MPS towards non-S. pyogenes indicators and presumed two-component inhibitor system (from two salMPS genes) further complicated the production scenario. In comparison, Streptococcus uberis strain NY42 which was selected from the screening study as an alternative salMPS producer demonstrated a more specific anti-S. pyogenes salMPS-like inhibitor activity while containing only one of the two salMPS genes found in strain MPS. Recovery of salMPS-like activity from strain NY42 was mainly achieved by freeze thaw method extraction of cultures grown on blood agar. The biggest challenge during the enrichment of the inhibitory activity using ammonium sulfate precipitation was the interference by large amounts of haemoglobin from the blood agar that associated with the inhibitory activity. Attempts at removing the haemoglobin from the inhibitory activity using guanidine hydrochloride and urea did not succeed. Fractionation of the NY42 freeze thaw sample using gel permeation HPLC (high pressure liquid chromatography) did indicate the presence of the putative salMPS-like inhibitor within the active fractions, supported by the SDS-PAGE (sodium dodecyl sulphate-polyacylamide gel electrophoresis) and mass spectrometry analysis results, although data from online database searching was less significant due to the lack of suitable library entries. The effect of blood and saliva as well as uv-irradiation on the production of inhibitory activity by several P-type 226 producer strains was also investigated in this study. In addition, the possibility of using S. pyogenes cells to bind salMPS-like activity, followed by an attempt to release the inhibitory activity was also assessed. Despite all the difficulties with the original producer S. salivarius strain MPS, the study of strain NY42 discovered an alternative producer capable of producing a similar but more specific inhibitory activity compared to strain MPS. Purification of salMPS-like inhibitor using HPLC, combined with 1D (one dimension) -PAGE and mass spectrometry analysis further demonstrated the possibility of using strain NY42 as a favorable salMPS producer.

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  • Corporate financial reporting on the internet: Evidence from New Zealand companies

    Wang, Yi (2003-09)

    Masters thesis
    University of Otago

    In this thesis, I examine companies that list on the New Zealand Stock Exchange and distribute financial information via the Internet. The types of financial information published on the Internet by these companies are identified, and the influence of firm size, financial performance, leverage, ownership spread, industry type, and the degree of internationalisation on the disclosure level of Internet financial reporting are investigated, based on the theoretical arguments of prior studies on this topic. It is found that, in general, companies place an electronic version of their printed material and some reorganised information on their websites. The results indicate that only firm size is significantly associated with the disclosure level of Internet financial reporting.

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  • Design and Evaluation of a Mobile Photo Gallery in TIP

    Wang, Yi (2007)

    Masters thesis
    University of Waikato

    As a part of the Tourist Information Provider (TIP) system, this project focuses on creating a photo gallery service in the TIP system, which allows users to share, browse and categorize their photos. The core of this project is to provide users a location-based photo browsing. The system provides photos which are taken in the current user's location. We considered privacy control on photos that users uploaded. A photo owner is able to sign an access level to each of their photos and permit different users to access them. We also considered reusing resources. The system allows a user to use an URL of a photo in the system in stead of uploading the photo from the local computer. The system also provides a URL of each photo in order to use the photo on other web places, e.g., Blogs. We use tags and photo metadata Eixf to categorize photos.

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  • Interpersonal conflict between employees and managers: The Chinese immigrants experiences of acculturation in New Zealand public sector workplaces

    Wang, Yi (2015)

    Masters thesis
    Victoria University of Wellington

    With the increase in globalisation and migration, the future workplace will become more culturally diverse. Significant literature points out that culturally diverse workplaces can create organisational conflict because of the workers’ differences in cultural values, attitudes, and work styles. New Zealand, like other countries, has also faced the challenge of an increasingly diverse workforce. Although the associations between cultural diversity and conflict management styles in different countries have been widely discussed, the existing literature focuses more on comparison studies with participants who are from different countries. There is a lack of research investigating Chinese employees who live overseas and work in overseas organisations. Research on how young Chinese migrants cope with conflict in New Zealand organisations is scarce. The purpose of this study is to explore Chinese migrant employees’ preferences for styles of conflict management and the reasons they perceive these styles, as well as the influence of acculturation and ethnic identity orientation. The study argues that acculturation, the process of cultural change, is one of the factors that relates to the use and perceptions of different conflict management styles. This study explores how immigrants who have acculturated, learned and adopted their host society’s cultural characteristics, perceived and faced conflict issues in the workplace. More particularly, this study investigates how the role of ethnic identity influences different conflict management styles. A qualitative phenomenological method is employed in this study to obtain a deeper picture of conflict phenomena among Chinese migrant employees who have been through the process of acculturation. This method is useful for describing the lived experiences of conflict and acculturation. The data consisted of twenty one in-depth interviews with Chinese migrant employees from mainland China who work in twenty different New Zealand public sector organisations. The findings of this study reveal that due to their acculturation experiences, interviewees have developed an integrated bicultural identity that is rooted in good feelings about being New Zealanders, accompanied by a positive sense of Chinese ethnic identity. They view their own identity as a combination of both New Zealand and Chinese identities. Depending on the situation and the nature of their interpersonal relationships, interviewees can switch between these two identities without a problematic struggle. Based on the influence of this integrated bicultural identity, the study finds that young Chinese migrant employees prefer to use a combination of integrating and compromising conflict management styles. The tendency to use integrating conflict management is highly influenced by their adaptation to New Zealand cultural values and attitudes. Being New Zealanders gives these bicultural Chinese migrant employees confidence to confront and integrate conflict directly, and solve it in cooperative manner. The findings also show that Chinese beliefs and values continue to be maintained. The principles of Confucianism are deeply rooted and included showing mutual respect, avoiding embarrassment to other parties, controlling emotions or psychological impulses. Under the influence of being Chinese, young Chinese migrant employees incline towards compromising style depending on the circumstances. However, if integrating and compromising styles fail to resolve the conflict because the other party refuses harmony and escalates the conflict, young Chinese migrant employees would change their strategies by asking for third-party interventions and seeking for a sense of justice and fairness.

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