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

ENGLISH TEACHERS’ SATISFACTION WITH THE QUALITY OF GENERAL ENGLISH PROFICIENCY TRAINING PROGRAM: THE CASE OF THE MEKONG DELTA, VIETNAM

Many policy changes in teaching and learning English in Vietnam have been implemented. To make those changes successful, the quality of English teachers is paid remarkable attention to by stakeholders. In particular, the quality of their teaching is said to be the determining factor in the success or failure of the changes. Since then, many professional development programs for English teachers have been implemented in Vietnam. This research explores Vietnamese teachers’ satisfaction with the effectiveness of a large-scale general English proficiency training program provided by MOET’s National Foreign Languages Project for school teachers in the Mekong Delta. Employing questionnaires with 174 school teachers in the Mekong Delta, the study sheds light on the main factors that these teachers perceive as crucial factors that influence the quality of the training program and their satisfaction. Findings from the survey reveal that the teachers were highly satisfied with the training program, and the critical factors impacting the training effectiveness included training materials, training duration, teaching and learning facilities, qualified trainers, and support from management. These findings provide a solid foundation for proposing an efficient model training program to effectively support English language teachers in the Mekong Delta to accomplish the required English proficiency level.  Article visualizations

NANOEMULSION OF MIXTURE Piper aduncum ESSENTIAL OIL AND FRAGRANT Cymbopogon nardus DISTILLED WASTE AND Bacillus thuringiensis STRAIN MRSNR3.1 TO CONTROL BACTERIAL LEAF BLIGHT ON SHALLOT (Xanthomonas axonopodis pv. allii)

ABSTRACT The bacterial species Xanthomonas axonopodis pv. allii (Xaa) is an important pathogen causing the leaf blight in shallots. This pathogen is known to be easily resistant to synthetic pesticides. Therefore, the use of botanical pesticides with nanoemulsion formulations has become a suitable alternative. The objective of the research was to obtain nanoemulsion from mixture of Piper aduncum essential oil and fragrant Cymbopogon nardus waste, thereby finding the optimal concentration to suppress Xaa growth while testing Bacillus thuringiensis strain MRSNR3.1 and its secondary metabolites toxicity against Xaa was carried out by the diffusion method using paper discs to determine the diameter of the inhibition zone was carried out in vitro. The results demonstrated that at a concentration of 1% (3.17 cm in diameter) of the nanoemulsion after 4 days of incubation, the inhibitory effect was higher than that of the concentration of 2.5 %, 5% and 7%, additionally, B. thuringiensis strain MRSNR3.1 (3.04 ± 0.44) and its secondary metabolites (2.21 ± 0.28) were both able to control Xaa. To determine the activity of peroxidase, polyphenol oxidase and phenylalanine ammonia lyase enzymes in shallots was performed by introducing nanoemulsion, B. thuringiensis strain MRSNR3.1 and bactericide of Streptomycin. The results showed that B. thuringiensis strain MRSNR3.1 had the highest activity in the roots and leaves of shallot on the three enzymes mentioned above. It can be seen that the induction of B. thuringiensis strain MRSNR3.1 increased the defense enzymes PO, PPO, PAL to the highest

Nanoemulsion from Piper aduncum, Cymbopogon nardus, and Bacillus thuringiensis to Control Xanthomonas axonopodis pv. allii

The bacterial species Xanthomonas axonopodis pv allii (Xaa) is an important pathogen causing leaf blight in shallots. The use of botanical pesticides with nanoemulsion formulations has become a common alternative. This study aims to determine the characteristics and optimum concentration of the mixture of essential oil of Piper aduncum and fragrant Cymbopogon nardus waste. Nanoemulsion formulations are made using spontaneous emulsification methods. Besides, testing Bacillus thuringiensis strain MRSNR3.1 and its secondary metabolites toxicity against Xaa was carried out by the diffusion method using paper discs to determine the diameter of the inhibition zone. The results demonstrate that all four concentrations, 1%, 2.5%, 5%, and 7.5%, could control Xaa bacteria. A concentration of 1% is considered more optimal than the other three   concentrations in bactericidal effects against Xaa, as manifested in the formed clear zone (diameter of 3.17 cm). Besides, Bacillus thuringiensis strain MRSNR3.1 and its secondary metabolites were also effective againstXaa after four days of incubation with inhibition zones of 3.04 ± 0.44and 2.21 ± 0.28, respectively. Hence, it is concluded that nanoemulsion at 1% concentration and Bacillus thuringiensis strain MRSNR3.1 have  bactericidal properties that can be used to control Xa

Support immunologique pour biocapteur : caractérisations physico-chimiques et biologiques

The aim of my PhD thesis, conducted as part of a collaboration between the laboratory of protein separation sciences and nanotechnology (Paris-Sud Galen Institute) and the Micro and Nano System (basic electronics institute) group was to study the influence of self-assembled monolayers on the biological activity of bioreceptor toward biosensor development. In this project, we choose the organosilanes that can bind covalently to the silicon. Two silanes (7-octenyl trichlorosilane(OTS) and 3- aminopropyltriethoxysilane (APTES)) were studied., Their impact on the stability and the functionality of bio- receptor , model mouse immunoglobulin G (IgG), were evaluated. Spectroscopic characterization by XPS and infra- red Fourier transformed (FTIR) was first carried out to assess that the silanized surface exhibit carboxylic groups. The homogeneity of the surfaces was measured by AFM. Then, IgG were immobilized on these supports, covalently and a topographic AFM study was conducted to measure the distribution of these antibodies. The orientation of the grafted antibody was investigated by immune-enzymatic assays. We have also evaluated the binding capacity of the IgG immobilized on both surfaces. Then, the impact of aging on APTES surface was evaluated by spectroscopics and biological methods.L’objectif de mon doctorat, réalisé dans le cadre d’une collaboration entre le laboratoire des protéines et nanotechnologies en sciences séparatives (institut Galien Paris-Sud) et le groupe Micro et Nano Système (institut d’électronique fondamentale) était d’étudier l’influence des monocouches autoassemblées, sur l’activité biologique du bio-récepteur dans une perspective de développement de biocapteur. Dans ce projet, nous avons choisi les organo-silanes qui peuvent se lier de manière covalente sur le silicium. Deux silanes (7-octenyl trichlorosilanes et le (3-aminopropyl)triethoxysilane) ont été étudiés, leur impact en terme de nature et de stabilité sur la fonctionnalité du bio-récepteur, des immunoglobulines G de souris, ont été évalué. Dans un premier temps, nous nous sommes intéressés à la fonctionnalité des anticorps greffés sur une mono couche auto-assemblée composée de 7-octenyltrichlorosilane (OTS) présentant à sa surface un groupement carboxylique. Une caractérisation spectroscopique par XPS et infra-rouge à transformé de Fourrier (FTIR) a tout d’abord été effectuée afin de vérifier la présence de ces groupements carboxyliques. L’homogénéité de la surface a été évaluée par AFM. Nous avons ensuite immobilisé ces anticorps, sur ces supports, de manière covalente et une étude topographique par AFM a été menée pour mesurer la répartition de ces anticorps. L’orientation des anticorps greffés a été évaluée à l’aide d’immuno-essais. Ensuite, nous avons comparé l’APTES, permettant l’obtention de plaques de silicium fonctionnalisé avec des groupements aminés à leur surface, avec l’OTS. Nous avons notamment comparé la capacité de capture des anticorps immobilisés sur ces deux types de silanes. Dans la dernière partie, l’impact du vieillissement d’un support immunologique préparé chimiquement en utilisant l’APTES a été évaluée sur le plan physico-chimique et biologique

New simplified analytical method for the Prediction of global stability of steel and composite sway frames

peer reviewedEurocode 4 is the European design code for composite construction; in its so-called EN 1994-1-1 version, the design of “non-sway buildings” is mainly covered. As a result, EC4 focuses on the check of structural elements like beams, columns, slabs and joints. However, in the last years, the construction of taller buildings and larger industrial halls without wind bracing systems tends to make global instability a relevant failure mode, which is not well covered by Eurocode 4. Recently, intensive experimental, numerical and theoretical investigations have been carried out at Liège University. The latter aimed at improving the knowledge in the field of sway composite building frames and at developing appropriate design rules. The rotational behavior of the beam-to-column composite joints is one of the key aspects of the problem to which a special attention has been paid. This paper reflects investigations carried out at Liege University on this topic. In particular, an innovative simplified analytical method to predict the ultimate loading factor and the associated collapse mode of both steel and composite frames subjected to static loadings is presented

RELATIONSHIP BETWEEN SERUM IRON AND CHARACTERISTICS SOCIAL POPULATION IN PATIENTS WITH HELICOBACTER PYLORI INFECTION

The objective of the study is to investigate the value of serum iron index in patients infected with Helicobacter pylori and find out the correlation between serum iron index and sociodemographic characteristics in patients infected with Helicobacter pylori at faculty 2 of University Medical Center Ho Chi Minh City. The study used CLO and HP CIM tests to determine the Helicobacter pylori infection status, and also collected the serum/plasma of the patient after the HP CIM test to investigate the serum iron index. The Stata 14.0 software was used to manage and analyse data, the ANOVA test was used to test for 3 means or more, and the Chi-squared test was used to test the difference in proportions between groups. The results showed that the serum iron concentration in the patient group was 59,4±42,1 mg/dL lower than the serum iron value in the control group, which was 86,1±32,0 mg/dL (p < 0,001). The results also indicated that the serum iron value in patients infected with Helicobacter pylori decreased as compared to patients without infection, yet the study also found a relationship between age group and geographical factors. This difference is statistically significant with p < 0,001, p = 0,001, p = 0,04 and p = 0,001

‘I’m not like that, why treat me the same way?’ The impact of stereotyping international students on their learning, employability and connectedness with the workplace

A significant body of literature on international education examines the experiences of international students in the host country. There is however a critical lack of empirical work that investigates the dynamic and complex positioning of international students within the current education-migration nexus that prevails international education in countries such as Australia, Canada and the UK. This paper addresses an important but under-researched area of the education-migration landscape by examining how the stereotyping of students as mere &lsquo;migration hunters&rsquo; may impact their study and work experiences. It draws on a four-year research project funded by the Australian Research Council that includes more than 150 interviews and fieldwork in the Australian vocational education context. Positioning theory is used as a conceptual framework to analyse how generalising international students as &lsquo;mere migration hunters&rsquo; has led to the disconnectedness, vulnerability and marginalization of the group of international students participating in this research

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