Dengue virus evolution in Southern Vietnam over the last ten years and utility of DENV-NSI as a diagnostic marker

Dengue is a major public health problem in many parts of the tropical developing world. Dengue is caused by infection with one of four serotypes of dengue virus (DENV1-4), which are arboviruses belonging to the Flaviviridae family. Although most DENV infections are asymptomatic, mild, or self-limited, a proportion of dengue fever cases result in clinically apparent disease that varies in severity from mild undifferentiated fever through to more severe syndromes, primarily dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS). The main work described in this thesis was to examine molecular epidemiology of DENV over the last 10 years in southern Vietnam (1999-2008) and to document DENV molecular epidemiology in the 2007 dengue outbreak in Dong Thap province, a Mekong Delta province, southern Vietnam. A further purpose was to assess the utility of two commercial NS1 antigen test kits, Platelia NSI-ELISA and NSI-Lateral Flow Rapid (NSI-LFRT), for early diagnosis of acute dengue infection in relation to immune status, DENV-reactive measurable IgM/lgG, viraemia level, and duration of illness prior to patient specimen collection. Sequence analyses of Vietnamese DENV-1 and DENV-2 revealed that these viruses comprised significant genetic diversity. DENV-2 exhibits 3 distinct genotypes, American/Asian, Asian I and Cosmopolitan. DENV-1 viruses have become predominant in Vietnam since 2006, and circulate as 6 distinct lineages within genotype 1. The most striking finding of this work was the replacement of DENV-2 genotype in the context of serotype shift occurring in southern Vietnam; both of which were temporally linked to increased disease incidence. The American/Asian genotype which has circulated in HCMC and surrounding provinces since at least 1987 was displaced by the DENV-2 Asian I genotype preceding the change in serotype from DENV-2 to DENV-1. However, negative selection appears to be the major evolutionary factor impacting DENV population dynamics. Evaluation of the diagnostic accuracy for the two commercial NS1 test kits consistently showed that viraemia level in acute phase NS1-positive patients is higher than in NS1-negative patients. NS1 sensitivity was also greater in patients with primary infection. Proportion of NS1 positivity was generally greater in DF cases. Duration of fever time prior to patient blood samples collected also contributes to NS I sensitivity. Both DENY-reactive IgG and IgM were negatively correlated with NS1 sensitivity, but IgG showed stronger influence on NS1 positivity rate. NS1 sensitivity is also different in individual infecting serotypes; DENY-2 consistently shows lower positive NS1 results for both test kits. Overall, NS1-LFRT was modestly less sensitive than Platelia NS1-ELISA but importantly, both Platelia NS1-ELISA and NS1-LFRT retain extremely high specificity of 100%. With a large number of whole DENY genome sequences generated in this study, it is a massive contribution to the DENY genome data in GenBank. In addition, results presented in this study contribute to current knowledge of the DENY genetic diversity which is of a fundamental importance in vaccine or drug designs. Results from the evaluation of the utility of NS1 antigen as a diagnostic marker provide further information of the strength and the weakness of the current NS1 antigen detection assays

Management des ressources humaines individualisé, axé sur les profils motivationnels : un outil d'augmentation du profit individuel et organisationnel.

Si pour l’individu, la motivation au travail n’est pas une nécessité absolue, de nombreuses études montrent qu’il y a un lien de cause à effet entre la motivation des salariés et la performance de l’entreprise. A l’issue de l’analyse des résultats de nos enquêtes auprès de cadres français et vietnamiens, nous présentons des recommandations pour la GRH dans sa mission d’assurer un double développement organisationnel et personnel des cadres. Elles portent sur les trois points suivants: –1) compréhension de la motivation des cadres et de l’influence des variables personnelles sur leur motivation; –2) mise en évidence des structures motivationnelles de cadres; –3) compréhension des profils motivationnels en vue d’un management individualisé des cadres. Enfin, les nouvelles pistes de recherche seront identifiées.Ressources humaines; Motivation au travail; Motivation des cadres;

Attitudes toward Self-Disclosure on Facebook: A Review of Perception, Emotion and Behavior in University Students

A number of social networking platforms have emerged as a result of the development of information and communication technology which have become increasingly user-friendly and full with valuable features. The social networking site with most users is Facebook. Teenagers, particularly college students use Facebook most frequently to study, gain information, entertain themselves and connect with others through self-disclosing personal information on the Facebook profile page. This quantitative study aimed to analyze the attitude of pedagogical students regarding self-disclosure on Facebook as represented through cognition, emotion and behavior concerning academic achievement. The survey was completed by 535university student’s majority in pedagogy. There were 41 students who used it for less than three years between three to five years by 218 students and 276 students who use it more than five years. The questionnaire was self-reported by participants to assess university students' attitudes toward self-disclosure on Facebook. The results indicate that pedagogical students with excellent academic achievement and more than five years of Facebook experience had the highest-level attitude toward self-disclosure on Facebook. The results indicate a positive relationship between cognition, emotion and influence factors students' Facebook attitudes. Future research on methods that enhance student positive disclosure can benefit from this study. Future research should examine how self-disclosure on Facebook relates to other aspects, such as Facebook usage time, financial state and perception of advantages and its disadvantages of Facebook in order to evaluate students' attitudes objectively

The effects of avian influenza on rural poultry farmers’ livelihood

The objective of this research was to investigate how HPAI (highly pathogenic avian influenza) shocks and threats affected livelihood assets of poultry farmers. The policies helping poultry farmers to mitigate HPAI at national and local levels and what livelihood strategies did the poultry farmers have in order to accommodate threats and outcomes by avian influenza in Yen Son and Tan Binh communes - Tam Diep town – Ninh Binh province? The study combined both qualitative and quantitative approaches in collecting data and information. The findings of this study find that poultry production can be considered as important for the livelihoods of rural people in Yen Son and Tan Binh communes. However, avian influenza broke out repeatedly in these two communes in four years of 2004, 2005, 2007 and early 2008. This affected both directly and indirectly, both negatively and positively the poultry farmers’ livelihood. Under the negative effects of avian influenza on poultry farmers’ livelihood, the government at national as well as local levels has had the culling programme to reduce the spread of avian influenza. Coupled with the culling programme is a compensation policy for the poultry farmers. According to the ideas of the farmers who kept ducks, the compensation levels of Ninh Binh province in 2004, 2005, and 2007 were too low as compared to the market value, but they agree with the compensation level in 2008. Nevertheless, the farmers who kept the local chicken show that the compensation levels of province in four years were not suitable for their local chicken. In addition, the poultry farmers did not get the compensation money of Ninh Binh province until after 6 months as from their poultry were culled. Despite that, the poultry farmers still reported sick birds to veterinary staffs. Besides, vaccination support policy and training courses have been implemented to help the poultry farmers in these two communes mitigate avian influenza in the long term. It appears that the compensation and vaccination supporting policies can be considered as helping poultry farmers in avian influenza mitigation, but the training courses have not contributed much. To cope with avian influenza shock in the short term, the poultry farmers get the assistance of both non- family and family network and came with temporary off- farm and non- farm employments such as working for Dong Giao farm, selling vegetable or construction work to earn a income for their living. To respond to avain influenza threats in the future, they have the risk management strategies decisions depending on household specific characteristics for example, many households stop poultry production and change to other activities. Nevertheless, the majority of households restarts poultry production, but makes technical changes and combines poultry production with other activities

Vietnam's ASEAN Chairmanship in Dispute Management of the South China Sea in 2010

This thesis examines the attempts of Vietnamese policy makers to manage the dispute with China on the South China Sea within the context of Vietnam’s ASEAN Chairmanship in 2010. In particular, it examines the actions of Vietnamese policymakers in the preparing and conducting the 2010 ASEAN Defence Minister Meeting Plus and ASEAN Regional Forum. It asks whether and how Vietnamese policymakers have utilized the ASEAN chairmanship and its agenda-setting powers to put the South China Sea issue and the Chinese in the spotlight at these meetings. It argues that Vietnamese policymakers sought to constrain Chinese actions in the South China Sea by raising international publicity on the issue. The thesis considers the strategic measures taken by Vietnamese policy makers in managing the South China Sea conflict from the perspective of two schools of thought in international relations: realism and constructivism. While realists and neo-realists suggest that the strong do what they can and the weak suffer what they must, constructivists argue that policy makers are social actors, who are concerned with the respect of others. Constructivist approaches offer a more convincing way to explain how and why Vietnam, a weaker state might try to constrain China, a much stronger state, on issues of sovereignty in the South China Sea. Finally, the thesis concludes that, despite several failures, Vietnamese policy makers were able to make progress in managing this conflict by using international publicity to constrain the Chinese from acting unilaterally

Investigating the elements influencing the psychological issues of reform school students

Reformatory students are those whose deviant behaviors and habits prevent them from receiving education under normal educational conditions. These students frequently lead a careless, undisciplined lifestyle, being unwilling to work and learn eager to play and demanding. Therefore, when they are admitted to reformatories with severe study and lifestyle requirements, they have great psychological difficulty adjusting to their new environment. Students’ psychological issues in adapting to reformatory learning and living regimes are difficult and psychological deficits make it challenging for students to adapt to reformatory learning and living conditions. In Vietnam, 665 students from reformatory schools were polled to determine the causes of psychological issues. According to the findings, a variety of elements contribute to students’ psychological difficulties. Individual student conditions such as health, awareness, attitudes and actions as well as inappropriate habits, living without goals or aspirations, etc. are on the subjective side of the equation. On the objective side are the students’ conditions, family, education and psychological obstacles brought on by less-than-ideal circumstances which will make it more difficult for community students to adapt. Both the new school and society must pay more attention to reformatory students in order to establish the conditions necessary for successful integration into the new school and ultimate readmission into society for these students

Depth of powers of edge ideals of Cohen-Macaulay trees

Let $I$ be the edge ideal of a Cohen-Macaulay tree of dimension $d$ over a polynomial ring $S = \mathrm{k}[x_1,\ldots,x_{d},y_1,\ldots,y_d]$. We prove that for all $t \ge 1$, $$\operatorname{depth} (S/I^t) = \operatorname{max} \{d -t + 1, 1 \}.$

Soybean yield, seed quality and thresh efficiency by mechanisation at different harvesting stages and postharvest ripening

This study determined the most appropriate and earliest soybean harvesting stage and the number of days of postharvest ripening with minimal effects on seed losses and quality when mechanical harvest and threshing were applied. Harvesting stages at four physiological maturities (60, 70, 80, and 90%) and various days of postharvest ripening treatment (1, 2, and 3 days) were applied for two soybean varieties DT12 and DT26. Harvesting at physiological maturity of 90% recorded the highest seed-shattering loss but the least seed damage (<5%) and highest seed quality, followed by a physiological maturity of 80%. There were no significant differences in seed yields between harvesting stages of 80 and 90% maturity. Harvesting soybeans at a physiological maturity of 60 and 70% resulted in no seed losses but a significant reduction in seed quality. To avoid adverse weather, an early harvest stage at a physiological maturity of 80% is suggested. Although postharvest ripening of soybeans for early harvest caused seed shattering losses (2-5%), it was necessary to ensure seed quality. These results indicate effective and practical methods for farmers at small households to use in early mechanical harvesting of soybeans

Lignin and Cellulose Extraction from Vietnam’s Rice Straw Using Ultrasound-Assisted Alkaline Treatment Method

The process of cellulose and lignin extraction from Vietnam’s rice straw without paraffin pretreatment was proposed to improve economic efficiency and reduce environmental pollution. Treatment of the rice straw with ultrasonic irradiation for 30 min increased yields of lignin separation from 72.8% to 84.7%. In addition, the extraction time was reduced from 2.5 h to 1.5 h when combined with ultrasonic irradiation for the same extraction yields. Results from modern analytical methods of FT-IR, SEM, EDX, TG-DTA, and GC-MS indicated that lignin obtained by ultrasound-assisted alkaline treatment method had a high purity and showed a higher molecular weight than that of lignin extracted from rice straw without ultrasonic irradiation. The lignin and cellulose which were extracted from rice straw showed higher thermal stability with 5% degradation at a temperature of over 230°C. The ultrasonic-assisted alkaline extraction method was recommended for lignin and cellulose extraction from Vietnam’s rice straw