Harmonizing multi-sectorial water management with minimum flow requirements in an anthropogenically impacted river basin. The case of Vu Gia – Thu Bon, Central Viet Nam

The low flow phenomenon is significantly concerned since it severely impacts socio economic activities. During low flow periods, diminished freshwater resources are often unable to provide adequate water for crop production, hydropower generation and urban water supply, as well as to maintain water quality of freshwater bodies due to high concentration of pollutants and saltwater intrusion. Accordingly, determining the required minimum flows in rivers during low flow periods is important to reduce the impact of saltwater intrusion and maintain a sustainable water supply for different water users such as agriculture, domestic use and industries. Located in the central coastal zone of Viet Nam, the Vu Gia – Thu Bon river basin experiences drought during the dry season along with salt intrusion due to low flow. The region was chosen as an in-depth case study since it provides crucial information regarding the low flow phenomenon and drought situation during the period 1976 - 2014. This research aims to develop a generally applicable methodology to assess minimum flow requirements in the rivers. The goal of this thesis is (1) to analyze the low flow phenomenon and minimum flow requirements; (2) to quantify the potential water demand from the different user categories; (3) to assess the performance of the existing irrigation system in regards to water supply availability and water demand; (4) to determine the required minimum flow to prevent salt intrusion and satisfy the water demand from different activities during low flow periods; and (5) to derive a generally applicable methodology to assess minimum flow requirements in multi-sectorial water management scenarios. Firstly, statistical analysis was conducted to examine trends in precipitation and flow during the study period. Thereafter, a flow duration curve and SPEI index were calculated to understand the flow pattern and drought events in the region. The potential water demand was quantified for the agricultural sector, as well as domestic and industrial uses to map the water utilization pattern. The Penman – Monteith equation was applied to calculate the potential evapotranspiration using the data from the dry year 2005. Furthermore, the performance of the irrigation system was accessed by analyzing the two indicators of Relative Water Supply and Relative Irrigation Supply. Finally, a calculation of the minimum flow requirement was carried out by applying the hydrodynamic model MIKE 11. The model was run for different upstream discharge datasets to test the response of the salt concentration, and then define where the salt concentration remains under threshold values at chosen measurement points. Six different scenarios were developed to predict the minimum flow requirements toward the changes in potential water use, sea level rise and water use efficiency. In general, the analysis of precipitation and flow revealed strong increasing trends, however these were mostly seen in rainy season. On the other hand, the SPEI index showed a decrease of drought events in the years post 2000. The yearly potential demand of the Vu Gia -Thu Bon Delta was calculated as 309 million m3, of which 203 million m3 is for agriculture, 89 million m3 is for domestic use, and only 17 million m3 is for industry. Furthermore, the analysis of Relative Water Supply and Relative Irrigation Supply revealed the constraints of the irrigation system to supply sufficient water for the crops, especially from February to June. Finally, the results of the six scenarios were mapped presenting the spatial and temporal extents of the minimum flow requirements in the Vu Gia – Thu Bon river basin. The described methodology includes transferable state-of-the-art techniques, making it an applicable approach to determine the minimum flow requirement in an anthropogenically influenced river basin. This methodology has been successfully tested in the Vu Gia - Thu Bon river basin and can be extrapolated to similar river basins

PREPARATION OF MAGNETIC HYDROGEL BY IN-SITU COPRECIPITATION PROCESS

This study describes a preparation of magnetite nanoparticle by co-precipitation of Fe(II) and Fe(III) in alginate hydrogel matrix. This simple process is sufficient for producing a superparamagnetic, well dispersible magnetite nanoparticle in polymer hydrogel matrix. Two approaches for iron ions loadings are induced. The first approach includes two steps, the hydrogel beads are formed before the iron ions are being diffused into the hydrogel matrix. The second approach is the simultaneous forming of hydrogel containing iron ions. The ions loaded hydrogel is then coprecipitated in the presence of ammonium hydroxide to afford iron oxide magnetite nanoparticles in alginate hydrogel matrix. The composition and characteristics of the hydrogel containing magnetite nanoparticle were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and transmission electron microscopy (TEM). The results showed that the particles size of magnetic nanoparticles prepared by in-situ coprecipitation method is around ~ 6 nm and smaller than that produced by normal coprecipitation method. The magnetic hydrogel exhibits superparamagnetic properties with the saturation magnetization of about 25 emu/g, the ratio of Mr/Ms about 0.8 ×10-3. Possessing the biocompatibility as well as superparamagnetism, the magnetite hydrogel is a promising materials for environmental and biomedical applications

Erosive Tooth Wear: Prevalence in GERD Patients and Education in US and Canadian Dental Schools

Specific aims were to determine the prevalence of erosive tooth wear (ETW) in gastroesophageal reflux disease (GERD) and control populations after controlling for other known risk factors (diet, medications, salivary flow rate and buffering capacity) and to survey US and Canadian dental schools regarding their teaching of ETW. ETW was determined for subjects recruited (GERD/Control) using the Basic Erosive Wear Examination (BEWE) index. A survey was also sent to all US and Canadian dental education programs. Results showed that prevalence of ETW in GERD subjects was 51.7% versus 18.2% for controls. ETW worsen with age and was the only co-factor investigated that significantly affected ETW. Although 100% of dental schools in the US and Canada taught dental erosion, only 15.3% of respondents could correctly identify clinical signs of dental erosion, showing that diagnosis of this condition remains unclear. Tooth wear index and diet counselling are also underutilized.Master of Scienc

Corporate governance and firm performance: Evidence from Vietnamese listed companies

The research aims to provide empirical evidence on the relationship between corporate governance and firm performance in Vietnam – a developing economy in Asia. It focuses on the corporate governance of Vietnamese listed companies with a data-set of the five-year period from 2011 to 2015. Vietnamese listed companies are governed and controlled by two boards, Board of Directors and Supervisory Board. The research investigates the impacts of directors’ and supervisors’ characteristics and ownership structure on firm performance. The outcomes reveal that most governance mechanisms employed by Vietnamese listed companies were not effective and had no effect on the companies’ performance, except for managerial ownership and Supervisory Board size. Specifically, management ownership and firm performance were negatively correlated. Additional analyses show a positive relationship between the number of supervisors and firm performance, which was measured by market-based measurement

The Relationship Between Corporate Social Responsibility and Employee Organizational Commitment in Multinational Corporations in Ho Chi Minh City

Based on the theoretical background of previous studies and the increasing context of personnel turnover in multinational companies, the authors conduct this study with the research objective to test and measure the impact of Corporate Social Responsibility (CSR) on employee’s organizational commitment through the effect of organizational identification and organizational trust. The combined qualitative and quantitative research methods were used to process and analyse the data. Research data was collected from 271 employees working in multinational corporations in Ho Chi Minh City. The study also discusses and provides some governance implications to help MNCs improve their social responsibility towards social and non-social stakeholders, employees, customers and the government as well as increase employee organizational engagement through identification and trust in the organization. Keywords: corporate social responsibility, employee organizational commitment, organizational identification, organizational trus

Comparing smell identification ability among different motor subtypes of Parkinson’s disease using the Vietnamese Smell Identification Test and the Brief Smell Identification Test

IntroductionOlfactory dysfunction is one of the most common non-motor symptoms of Parkinson's disease (PD). The association between smell identification ability and motor subtypes of PD is not uniform in previous studies. This study aimed to compare the odor identification ability among different motor subtypes of PD in Vietnamese participants.MethodsPatients who were diagnosed with PD according to the International Parkinson's Disease and Movement Disorder Society 2015 Diagnostic Criteria and had normal cognitive function were recruited. Participants were divided into akinetic-rigid (AR), tremor-dominant (TD), and mixed (MX) motor subgroups using the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) score. Olfactory identification ability was evaluated using the Vietnamese Smell Identification Test (VSIT) and the Brief Smell Identification Test (BSIT). Cognitive status was assessed using the Mini-Mental State Examination (MMSE). Age, age at PD onset, disease duration, smell identification ability, and cognitive function were compared among the three PD motor subtypes.ResultsThe AR subgroup was the most common motor subtype (n = 164, 75.2 %), followed by TD (n = 39, 17.9 %), and MX (n = 15, 6.9 %) subtypes. Age, age at PD onset, sex, disease duration, and MMSE score were not significantly different between the three motor subgroups (all p > 0.05). The median (IQR) VSIT scores of AR, TD, and MX subgroups were 5.00 [4.00;7.00], 5.00 [3.50;7.00], and 5.00 [3.00;6.00], respectively. The median (IQR) BSIT scores of AR, TD, and MX subgroups were 6.00 [4.00;7.00], 5.00 [4.00;7.00], and 5.00 [4.50;7.00], respectively. The VSIT and the BSIT scores were not significantly different among the three motor subtypes (all p > 0.05).ConclusionSmell identification ability assessed in both the VSIT and BSIT did not differ across the three motor subtypes of PD

Diagnostic value of vietnamese smell identification test in Parkinson's disease

IntroductionThe Vietnamese Smell Identification Test (VSIT) has been validated in determining olfactory dysfunction in the Vietnamese population; however, its value in diagnosing Parkinson's disease (PD) has not been established.MethodsThis case-control study was conducted at University Medical Center HCMC, Ho Chi Minh City, Vietnam. The study sample included non-demented PD patients and healthy controls (HC) who were gender- and age-matched. All participants were evaluated for odor identification ability using the VSIT and the Brief Smell Identification Test (BSIT).ResultsA total of 218 HCs and 218 PD patients participated in the study. The median VSIT and BSIT scores were significantly different between PD and HC groups (VSIT, 5 (3) vs. 9 (2), P < 0.0001; BSIT, 6 (3) vs 8 (2), P < 0.0001). Using the cut-off of <8 for correct answers out of 12 odorants, the VSIT had higher sensitivity (84.4%) and specificity (86.2%) than those of the BSIT (sensitivity of 81.7% and specificity of 69.3%) for the diagnosis of PD. The area under the curve (AUC) value was greater for the VSIT than for the BSIT (0.909 vs 0.818). The smell identification scores were not significantly correlated with disease duration, disease severity, or LEDD (all p > 0.05).ConclusionThe VSIT can be a valuable ancillary tool for supporting the diagnosis of PD in Vietnam. Olfactory dysfunction in PD was unrelated to the disease duration and severity. The VSIT can be applied to improve the accuracy of clinical PD diagnosis

Self-injurious Behavior of Children with Autism in Vietnam: Across Sectional Study

This study explored self-injurious behaviour (SIB) of autistic children in Vietnam through a crosssectional design. 60 informants, including 57 parents and 3 caregivers completed the questionnaire on problem behaviour consisting of aggression, self-injury, stereotyping, property destruction, other problem behaviours and their functions. Results revealed that children experienced all mentioned problem behaviours, especially self-injurious behaviour. The topographies of self-injurious behaviour of the children included head-hitting, head-scratching, head-banging, hair-pulling, face-hitting, facepuncturing with a pen, ear-scratching, lip-picking, hand-biting, hand-scratching, hand-pinching, and belly-scratching. The most common area of self-injurious behaviour is the head. The functions of these problem behaviours were expressed in four types (social positive reinforcement, social negative reinforcement, automatic positive reinforcement and automatic negative reinforcement). Social positive reinforcement appeared as a prominent function. Out of these 57 children, 21 of them who were autistic with self-injurious behaviour went through a functional behaviour assessment (FBA) in which the four conditions known as attention, tangible items, escape from task/activities, automatic stimulation were tested. The results of functional behaviour assessment (FBA) further indicated the correspondence between the FAST-R and FBA outcome on function of problem behaviour, especially self-injurious behaviour. The research concluded that the prominent function of these self-injurious behaviours was social function. It means self-injurious behaviours usually occur within a condition of social interaction, especially, in this present study, in the tangible condition. The antecedent of selfinjurious behaviour is the removal of tangibles (e.g. food, preferred items). This paper contributes to our knowledge of self-injurious behaviour of children with autism in Vietnam where empirical research of this field was still very rare

Cytotoxic constituents from Vietnamese Pterospermum truncatolobatum Gagnep.

32-35Pterospermum truncatolobatum Gagnep. has long been used as a traditional medicine in Vietnam. Its crude extract showed cytotoxicity against human epidermal carcinoma (KB) cell lines. However, its chemical constituent and biological activity remains unknown. In the course of our investigation on the Vietnamese medicinal plants, four compounds, taraxerol (1), betulonic acid (2), -sitosterol (3) and eicosanoic acid (4) were purified from methanolic extract of P. truncatolobatum by silica gel column chromatography. Their structures were determined by spectral (Mass spectrometry and nuclear magnetic resonance) analysis and by comparison with the literature reports. Of which, betulonic acid (2) showed moderate cytotoxicity against all four cancer cell lines, KB, MCF7 (human breast carcinoma), LU (human lung carcinoma), and HepG2 (hepatocellular carcinoma)

Impact of equity structure on risk of financial distress in Vietnam

This study aims to evaluate the impact of transparency of budget structure on risk of getting into financial distress in Vietnam. The article uses data regarding equity proportion from the financial reports of business entities on Hanoi Stock Exchange (HNX), divided into four main categories, namely large ownership, institutional ownership, managerial ownership, and state ownership ratio, to find the relation between the allocation of equity and the chance a company having financial failure. From the mentioned information, the research attempts to explain the relations, as well as suggestions for companies to prepare and avoid financial distress from an equity structure perspective. Results from the study’s sample show insignificant correlations between the share of owners and financial distress situation of a company, which plays a part to help the overall estimation of risk in businesses as a whole