Factor substitution in rice production function: the case of Vietnam

Vietnamese rice production has achieved remarkable success over the last couple of decades. This is due to land and market reforms, known as ‘Doi Moi’. There were noticeable changes in policies, such as land and production systems, which were transformed from a collective to an individual contract system in the 1980s. Vietnam made progress in rice production through the legalisation of the privatisation of farm properties and a huge investment in irrigation systems. The country not only ensured its domestic demand, but also started exporting rice and gradually became the second largest exporter in the world. An estimate of the Constant Elasticity of Substitution function (CES) for Vietnam’s rice production is essential for the government to design effective policy on agricultural production. This study makes the first attempt to estimate the nested CES model for Vietnamese rice production in 2012. The paper finds that the elasticity of substitution of Vietnam’s nested CES model lies between 0.44 and 0.46. The results indicate the weak substitutability between land and the capital-labour composite in the nested CES model. This also suggests that it is impossible to take labour as the substitutable factor for land and capital

The influence of human genetic variation on early transcriptional responses and protective immunity following immunization with Rotarix vaccine in infants in Ho Chi Minh City in Vietnam : a study protocol for an open single-arm interventional trial [awaiting peer review]

Background: Rotavirus (RoV) remains the leading cause of acute gastroenteritis in infants and children aged under five years in both high- and low-middle-income countries (LMICs). In LMICs, RoV infections are associated with substantial mortality. Two RoV vaccines (Rotarix and Rotateq) are widely available for use in infants, both of which have been shown to be highly efficacious in Europe and North America. However, for unknown reasons, these RoV vaccines have markedly lower efficacy in LMICs. We hypothesize that poor RoV vaccine efficacy across in certain regions may be associated with genetic heritability or gene expression in the human host. Methods/design: We designed an open-label single-arm interventional trial with the Rotarix RoV vaccine to identify genetic and transcriptomic markers associated with generating a protective immune response against RoV. Overall, 1,000 infants will be recruited prior to Expanded Program on Immunization (EPI) vaccinations at two months of age and vaccinated with oral Rotarix vaccine at two and three months, after which the infants will be followed-up for diarrheal disease until 18 months of age. Blood sampling for genetics, transcriptomics, and immunological analysis will be conducted before each Rotarix vaccination, 2-3 days post-vaccination, and at each follow-up visit (i.e. 6, 12 and 18 months of age). Stool samples will be collected during each diarrheal episode to identify RoV infection. The primary outcome will be Rotarix vaccine failure events (i.e. symptomatic RoV infection despite vaccination), secondary outcomes will be antibody responses and genotypic characterization of the infection virus in Rotarix failure events. Discussion: This study will be the largest and best powered study of its kind to be conducted to date in infants, and will be critical for our understanding of RoV immunity, human genetics in the Vietnam population, and mechanisms determining RoV vaccine-mediated protection. Registration: ClinicalTrials.gov, ID: NCT03587389. Registered on 16 July 2018

Safety and efficacy of fluoxetine on functional outcome after acute stroke (AFFINITY): a randomised, double-blind, placebo-controlled trial

Background Trials of fluoxetine for recovery after stroke report conflicting results. The Assessment oF FluoxetINe In sTroke recoverY (AFFINITY) trial aimed to show if daily oral fluoxetine for 6 months after stroke improves functional outcome in an ethnically diverse population. Methods AFFINITY was a randomised, parallel-group, double-blind, placebo-controlled trial done in 43 hospital stroke units in Australia (n=29), New Zealand (four), and Vietnam (ten). Eligible patients were adults (aged ≥18 years) with a clinical diagnosis of acute stroke in the previous 2–15 days, brain imaging consistent with ischaemic or haemorrhagic stroke, and a persisting neurological deficit that produced a modified Rankin Scale (mRS) score of 1 or more. Patients were randomly assigned 1:1 via a web-based system using a minimisation algorithm to once daily, oral fluoxetine 20 mg capsules or matching placebo for 6 months. Patients, carers, investigators, and outcome assessors were masked to the treatment allocation. The primary outcome was functional status, measured by the mRS, at 6 months. The primary analysis was an ordinal logistic regression of the mRS at 6 months, adjusted for minimisation variables. Primary and safety analyses were done according to the patient's treatment allocation. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000774921. Findings Between Jan 11, 2013, and June 30, 2019, 1280 patients were recruited in Australia (n=532), New Zealand (n=42), and Vietnam (n=706), of whom 642 were randomly assigned to fluoxetine and 638 were randomly assigned to placebo. Mean duration of trial treatment was 167 days (SD 48·1). At 6 months, mRS data were available in 624 (97%) patients in the fluoxetine group and 632 (99%) in the placebo group. The distribution of mRS categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio 0·94, 95% CI 0·76–1·15; p=0·53). Compared with patients in the placebo group, patients in the fluoxetine group had more falls (20 [3%] vs seven [1%]; p=0·018), bone fractures (19 [3%] vs six [1%]; p=0·014), and epileptic seizures (ten [2%] vs two [<1%]; p=0·038) at 6 months. Interpretation Oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and epileptic seizures. These results do not support the use of fluoxetine to improve functional outcome after stroke

Preparation of mesoporous MgO: phenomena occurred during the calcination

Mesoporous MgO has been synthesized in the presence of the neutral block co-polymer surfactant Pluronic F127. The characterization of synthesized material was carried out by mean of X-ray diffraction (XRD), scanning electron microscope (SEM) and Brunauer-Emmett-Teller technique (BET). The obtained MgO exhibited a value of the surface area of 157 m2/g and showed a narrow pore size distribution centered at 4.3 nm. The phenomena and gas evolved during calcinations have been investigated by thermogravimeter-mass spectrometer (TG-MS). During the calcinations, the precursor Mg(OH)2 was converted to MgO with a mass loss of 29% and with the formation of H2O (>60% of the gas evolved). The desorption of CO2 and a small amount of CO and/or N2 which were adsorbed from air on the surface of Mg(OH)2 were also observed. No organic compounds were found which indicated that F127 was completely removed by Soxhlet extraction

Factors Associated with Improved HIV/AIDS Treatment Outcomes: Comparing two Major ART Service Delivery Models in Vietnam

A mixed design approach was performed to assess the CD4 count levels over time and their associated factors among 362 HIV patients on ART from clinics with HIV testing and counseling (ART-HTC) services and those with general healthcare (ART-GH) services. Longitudinal CD4 count data were retrospectively collected from medical records. Sociodemographic, clinical, alcohol use and smoking characteristics were obtained via face-to-face interviews. Multivariate mixed effect linear regression was utilized to determine the association. We found that HIV patients at ART-GH clinics were more likely to achieve higher CD4 counts over time compared to patients at ART-HTC clinics. Additionally, having an increase in CD4 counts was found to be associated with having longer duration of ART and higher baseline CD4 levels. Cigarette smoking and hazardous alcohol use, however, were not associated with CD4 count improvement. Our findings suggest that combining HTC and GH services might provide a synergistic benefit in ART treatment outcomes through an improved access to comprehensive HIV healthcare services for HIV patients on therapy

Reliability of online dental final exams in the pre and post COVID-19 era: A comparative study.

Amidst the fourth COVID-19 wave in Viet Nam, national lockdowns necessitated the closure of numerous dental schools. To assess DDS (Doctor of Dental Surgery) graduation exams, this study analyzed their 2021 implementation in comparison to onsite exams conducted in 2020 and 2022 at the Faculty of Odonto-Stomatology, University of Medicine and Pharmacy at Ho Chi Minh City, Viet Nam (FOS-UMPH). The final online examination comprises two main sessions: a synchronous online examination using FOS-UMPH e-Learning for theories (consisting of 200 MCQs and 3 written tests with 3 clinical situations needed be solved) and a synchronous online examination using Microsoft Teams for practicum (comprising of 12 online OSCE stations). The final grades were evaluated using the same metrics in face-to-face final examinations in 2022 and 2020. A total of 114, 112 and 95 students were recruited for the first-time exams in 2020, 2021 and 2022, respectively. In order to analyze the reliability, histogram and k-mean clustering were employed. The histograms from 2020, 2021 and 2022 showed a striking similarity. However, fewer students failed in 2021 and 2022 (13% and 12.6%, respectively) compared to 2020 (28%), with clinical problem-solving part grades (belonging to theory session) being notably higher in 2021 and 2022. Intriguingly, the MCQ Score results showed the identical patterns. The courses of orthodontics, dental public health, and pediatrics subjects (in the group of prevention and development dentistry) stood out for their exceptional accuracy across both sessions. After examining data gathered over three years, we identified three distinct clusters: the first comprised of scattered average and low scores, the second characterized by high scores but unstable and scattered and the third cluster boasting consistently high and centered scores. According to our study, online and onsite traditional graduation exam results are relatively equivalent, but additional measures are necessary to standardize the final examination and adapt to the new normal trend in dental education

Sex Differences in Quality of Life and Health Services Utilization among Elderly People in Rural Vietnam

In Vietnam, as in much of the world, the elderly population is growing rapidly. Two-thirds of Vietnam&rsquo;s elderly live in rural areas, where there may be unique health profiles and needs. Furthermore, the sex ratio in the elderly population is highly skewed. The relationship between sex, health-seeking behavior, and health outcomes in elderly individuals residing in rural areas has not been well-characterized, and needs to be elucidated in order to better serve this population. This study sought to explore the associations of sex with health and health-seeking behavior among the elderly in Soc Son, a rural district of Hanoi. A cross-sectional design was employed; elderly women and men were surveyed across the domains of socioeconomic information, health status, and healthcare service utilization. We found differences between women and men in sociodemographic characteristics, quality of life, health outcomes, and patterns of health services utilization. Overall, women had poorer health and quality of life, but no difference was found between sexes regarding level of health services utilization. Future research should expand upon these findings and, moreover, characterize their underlying systemic, sociocultural, and psychological mechanisms, in order to help bring solutions to improve the health of elderly persons in rural parts of Vietnam