Essays on the Vietnam Stock Market

This thesis consists of three substantive studies about the Vietnam stock market. In particular, I study the asymmetric information, corporate governance (CG) practices, and foreign investment of publicly listed companies in Vietnam, presented in Chapters 2, 3, and 4, respectively. In Chapter 2, I investigate the effectiveness of a market surveillance system (MSS) on improving the market quality of the Vietnam stock market, as measured by liquidity and informed trading level. I find that market liquidity decreased after the introduction of the MSS, and that the effect is more pronounced for small firms. Although informed trading, on average, does not change significantly after the MSS, subsample analysis indicates a significant decrease in informed trading among large and liquid firms. In Chapter 3, I investigate the relationship between firms’ CG practices and informed trading. I find a negative relationship between the two variables. Firms with better CG practices have a lower level of informed stock trading. Moreover, a natural experiment on a shock of firms’ CG practices generated by the CG policies shows that the negative relationship between CG practices and informed trading is a causal one, in which a change in the former causes a change in the latter. In another analysis around the implementation of the MSS, I find that the implementation of the surveillance system affects the relationship between the two variables, and this effect is driven by large and liquid firms. In Chapter 4, I investigate whether foreign investors in the Vietnam stock market are informed about firms’ performance. Using the residuals of foreign investor ownership as a measure of the abnormal foreign investor holding, I find that the abnormal foreign investor holding is positively correlated with firm performance in the following one year. I also find a positive correlation between abnormal foreign investor holding and the stock returns in the next three quarters. These findings indicate that foreign investors are informed about the firms up to a one-year period

Forest - Related Culture and Contribution to Sustainable Development in the Northern Mountain Region in Vietnam

The culture of communities living near/in forests indelibly interacts with forest ecosystems, both shaping and adapting to the natural environment. Forest-related cultural dimensions also provide benefits for local economies and social welfare. This study analyses the relationship between local culture and forests of the Tay and the Dao minorities and their contribution to sustainable development in Vo Nhai, a mountainous district in northern Vietnam. The study uses methods of a literature review, participant observation and qualitative interviews with local people. The strong embedded culture with forests that developed over many generations of Tay and Dao people was expressed through their knowledge systems of understanding nature, skills for environmental adaption, health protection and spiritual and recreational activities. The potentials of forest - related culture as a feature of local sustainable development were analysed through contributions in natural resource conservation, economic development and social cohesion. To integrate forest - related culture in sustainable development, some issues need to be better focused on the locality

The psychological impact of the COVID-19 epidemic among healthcare workers at the grassroots level in Vietnam

The COVID-19 pandemic has significantly affected the mental health of healthcare workers (HCWs). Therefore, an immediate priority is to monitor rates of mental health issues to understand related factors and inform interventions. The main purpose of this study was to evaluate the psychological and mental health impact of COVID-19 and some related factors among HCWs at the grassroots level in Vietnam. A cross-sectional study was conducted on 675 HCWs working at health facilities through questionnaires. The finding showed the rate of HCWs who were psychologically affected by the COVID-19 pandemic was 37.2%, of which 64.1% of HCWs were afraid to tell their families about the risk of exposure to COVID-19 at work. The 31.0% of HCWs had difficulty sleeping deeply/insomnia due to the COVID-19 epidemic. No statistically significant differences were found in the psychological impact of COVID-19 between HCW groups by age, gender, seniority, and professional qualifications. Some groups of HCWs were found to have poor psychological health. Our research suggests that during the COVID-19 pandemic, HCWs working in healthcare facilities experienced an increased psychological burden; psychological interventions for those at high risk and with common mental disorders should be included to reduce this burden and protect HCWs' mental health

Knowledge of tuberculosis among physicians working at community health stations in Vietnam

Tuberculosis (TB) remains a significant health problem worldwide, including in Vietnam, where around 174,000 newly diagnosed cases and 13,200 patients died in 2018. There are challenges in the diagnostic process, treatment, and follow-up. The physicians with knowledge of TB working at commune health stations play an essential role in this struggle. The primary purpose of this study was to evaluate knowledge of TB and related factors among physicians working at community health stations in the Northern provinces of Vietnam. A cross-sectional survey was implemented on 335 physicians working at community health stations in 5 Northern provinces in Vietnam from September 2019 to October 2020. The result showed that the TB knowledge of physicians was not good. There were some severe knowledge gaps concerning at-risk groups, the main symptoms of TB, sputum tests for both diagnosis and follow-up and management of attack therapy. The TB training participants had better TB knowledge than others (aOR=1.68; 95%CI: 1.047-2.712). This study underlines the importance of clinical experience and TB training to TB knowledge. We suggest that a TB training plan is required for physicians. Our survey results could inform the process of defining the physicians who work at community health stations' role in TB management in the future

RESEARCH TRENDS ON COMMUNITY-BASED TOURISM IN THE PERIOD 2013 - 2023

Community-based tourism (CBT) has been around since the 1970s and so far, has grown in popularity in most continents. This study systematically evaluates and generalizes theoretical and practical issues on CBT based on 87 related articles published in scientific journals under the Scopus system from 2013 to 2023 through the application of content analysis methods. The results also show that research in this area has different research areas and mainly uses qualitative methods. The literature review identified a number of key themes including: (1) benefits of CBT development, (2) community and stakeholder engagement, (3) advantages and barriers in CBT development, (4) community perceptions about CBT, and (5) sustainable CBT development. The article has analyzed research trends on CBT: theory and application.  Article visualizations

ASSESSING THE SATISFACTION OF DOMESTIC TOURISTS WITH ECO-TOURISM DEVELOPMENT IN MANG DEN TOWN, KON PLONG DISTRICT, KON TUM PROVINCE, VIETNAM

Mang Den town, Kon Plong District, the Central Province of Kon Tum is one of the destinations of recent interest. With the advantage of the climate and unique high mountain ecosystem, eco-tourism development is one of the notable trends in Mang Den. Based on a survey of 130 domestic tourists to Mang Den, the study used SPSS software 20 to analyze domestic tourists' satisfaction with eco-tourism development in Mang Den. The findings of this research demonstrated the potential of ecotourism Mang Den Town as a destination for Vietnamese tourists seeking natural beauty, cultural experiences, and adventure activities. The positive satisfaction levels indicated that efforts have been made to provide a quality tourism experience. However, there is still room for improvement, particularly in infrastructure development and providing more interpretive and accommodation options. These results can guide tourism stakeholders in developing strategies to enhance ecotourism in Mang Den Town, as a Good Practice and ensure sustainable tourism growth in the Kon Plong District, Kon Tum Province.  Article visualizations

ASSESSMENT OF THE CURRENT SITUATION OF TOURISM DEVELOPMENT IN MANG DEN TOWN, KON PLONG DISTRICT, KON TUM PROVINCE, VIETNAM

This study surveyed 120 domestic tourists in Mang Den Town, using the convenience sampling method. The method used to analyze primary data was descriptive statistics. The research results have proposed six factors to evaluate the current situation of tourism development in Mang Den Town, Kon Plong District, Kon Tum Province, Vietnam including: (1) Quality of tourism services and tourism resources; (2) Perceived prices; (3) Human resources; (4) Security, order, and safety; (5) Quality of tourism services and tourism infrastructure; (6) and Tourism resources and perceived prices, in which "Human resources" is the factor that has the strongest impact on the current situations of tourism development in Mang Den Town. Through research results, the article has proposed some solutions to develop tourism in Mang Den Town more effectively in the future.  Article visualizations

Vacuum Stability in Supersymmetric Reduced Minimal 3-3-1 Model

We investigate the vacuum stability conditions of theSupersymmetric reduced minimal 331 model (SUSYRM331) that createimportant  consequences on  Higgs mass spectrum as well assoft-parameters of the model. We prove that if this condition issatisfied then all Higgses are massive. Furthermore,soft-parameters should be in order of $SU(3)_L$ scale. Based onthis, we investigate in detail masses of CP-even neutral  anddoubly charged Higgses in the model. The  neutral Higgs sectorincludes one light Higgs with mass at tree level $m_{H^0_1}\simeq m_Z|\cos 2\gamma | 92.0$ GeV and three other heavy Higgses. Fordoubly charged Higgses, there may exist a light Higgs which can beobserved by recent colliders such as LHC

Sintering behavior and physical properties of Bi0.5(Na1–xKx)0.5SnO3 lead-free ceramics

In this study, Bi0.5(Na1–xKx)0.5SnO3 (BNKS) ceramics (x = 0, 0.1, 0.2, 0.3, and 0.4) were fabricated via ultrasound wave before milling. The time of ball milling decreased from 20 to 1 h. The X-ray diffraction patterns show that the BNKS has a single-phase structure. When the potassium content increases, the phase structure of the ceramics changes from rhombohedral to tetragonal. When sintered at 1100 °C and x = 0.2, the ceramics’ physical properties are the best with the mass density of 5.59 g/cm3, the electromechanical coupling constants kp of 0,31 and kt of 0.27, the remanent polarization of      11.9 µC/cm; the dielectric constant εr of 1131, and the highest dielectric constant emax of 4800

Antibacterial activity of crude methanolic and fractionated extracts of Aaptos suberitoides

In this research, we at the first time assessed antibacterial effects of methanolic crude and fractionated extracts from the marine sponge, Aaptos suberitoides against three bacterial strains including E. coli., S. aureus, B. cereus. The anti-bacterial assays were carried out by the disc diffusion method to test the anti-bacterial activity of different concentrations of methanolic crude of A. suberitoides against the indicator bacterial pathogens. The results indicated that extracts of A. suberitoides exhibited anti-microbial activity against all tested bacterial strains in concentrationdependent manner. Moreover, we showed that the majority of the active compound was in the polar fractions