DEGRADATION OF DEPROTEINIZED NATURAL RUBBER BY GORDONIA SP. ISOLATED FROM ENRICHMENT CONSORTIA

Biodegradation is a potential way of decomposing deproteinized natural rubber (DPNR). The enrichment consortia were demonstrated from a rubber processing factor waste. Nine DPNR-degrading bacteria were isolated from those consortia. The highest DPNR film weight loss in a mineral salt medium (MSM) was 43.92 ± 2.30 % after 30 days incubation using strain 5A1. The formation of aldehyde group during rubber degradation of 5A1 was determined using Schiff staining and Fourier Transform Infrared spectroscopy (FTIR) analysis. The 16S rRNA gene sequence, of 5A1 showed the highest identity with that of Gordonia soli CC-AB07. This is the first report to demonstrate a strong ability to degrade DPNR by Gordonia sp

Defining the Aetiology and Antimicrobial Susceptibility Patterns of the Predominant Bacteria Associated with Bloodstream Infections at the Hospital for Tropical Diseases in Ho Chi Minh City, Vietnam

Bloodstream infections (BSI) are among the most common critical diseases that require intensive care and continuous surveillance. According to many multinational antimicrobial resistance surveillance schemes, Asia represents a substantial reservoir of clinically relevant antimicrobial resistant genes. These genes include extended spectrum Beta lactamases (ESBLs) and AmpC lactamases in the Enterobacteriaceae, methicillin-resistance genes in Staphylococcus aureus, carbapenemase-resistance genes in Gram-negative bacilli and vancomycin-resistance genes in enterococcus. Asian countries are also burdened with high prevalence of HIV, in which BSI can be a major health problem in these immunocompromised people. Currently, there are no national data regarding the pathogens associated with BSI in Vietnam. Additionally, there are limited BSI data in specific populations, such as those infected with HIV, and there is limited information regarding the distribution and epidemiology of hospital-acquired and community-acquired infections. Data contributing to our understanding of common antimicrobial resistance mechanisms or profiles, including ESBLs, AmpC, KPC, and MRSA in BSI pathogens in Vietnam are also scarce. The aims of this study were to describe the characteristics of BSI in the Hospital for Tropical Diseases (HTD), a tertiary healthcare facility for infectious diseases in the south of Vietnam. I aimed to identify the most common BSI pathogens and their antimicrobial resistance profile in the context of the aetiological agent and disease outcome. Further, I aimed to define the specific types of ESBLs and AmpC genes circulating in Gram-negative bacilli isolated from BSI patients. I further describe the clinical and laboratory characteristics of BSI infections caused by the non-typhoidal Salmonella (iNTS) a particular group of BSI pathogens that are prevalent in immunocompromised patients. Lastly, I aimed to validate an automatic antimicrobial susceptibility testing system for Salmonella isolates in comparison to manual testing methods. I found that BSI in HTD was characterised by a low annual blood culture positivity rate (7%) and a declining annual trend of mortality. A high proportion of BSI was from patients in the intensive care unit (33%) and the HIV ward (22%). I report an increased trend of multidrug-resistant Gram-negative and Gram-positive pathogens in both hospital-acquired and community-acquired BSI infections. I additionally report a case study for BSI due to Vibrio cholerae non-O1, non-O139 and the first-ever outbreak report of Brucella melitensis in Vietnam. I performed molecular characterisation for all Gram-negative organisms isolated over a four-year period that exhibited reduced susceptibility against 3rd cephalosporin. Phenotypic screening found 304/1,017 (30%) organisms that were resistance to third generation cephalosporins; 172/1017 (16.9%) of isolates exhibited ESBL activity, 6.2% (63/1017) had AmpC activity, and 0.5% (5/1017) had both ESBL and AmpC activity. E. coli and Aeromonas spp. were the most common organisms associated with ESBL and AmpC phenotypes, respectively. There was no significant difference (p>0.05) between antimicrobial resistance phenotypes of organisms associated with community and hospital-acquired infections. I retrospectively identified 102 cases of iNTS infections in HTD between 2008 and 2013. Of 102 iNTS patients, 71% were HIV-infected, >90% were adults, 71% were male, and 33% reported intravenous drug use. Twenty-six/92 (28%) patients with a known outcome died; HIV infection was significantly associated with death (p=0.039). S. Enteritidis (Sequence Type (ST)11) (48%, 43/89) and S. Typhimurium (ST19, 34 and 1544) (26%, 23/89) were the most commonly identified serovars; S. Typhimurium was significantly more common in HIV-infected individuals (p=0.003). Through comparison of different antimicrobial testing methods for Salmonella, I identified a problematic agreement or errors were with quinolone antimicrobials. I found that the VITEK automatic antimicrobial susceptibility testing system did not produce satisfactory results for the Salmonella. However, the disk-diffusion method was a more reliable method for testing beta-lactams, azithromycin, and trimethoprim-sulfamethoxazole. In conclusion, BSI in HTD are characterised with an increasing trend of multi-drug resistant organisms that will challenge clinical and laboratory diagnostic as and future treatment options

Solutions for development of Vietnamese electronics industry in joining in world trade organization

Thesis(Master) --KDI School:Master of Public Policy,2008masterpublishedby Huong, Nguyen Lan

Essays on risk attitudes, knowledge, extreme weather, and farmers' behaviors in rural Southeast Asia

Northeastern Thailand and Central Vietnam are two regions where pockets of poverty persist despite overall success in poverty reduction on the national level. While there are profound structural differences between Thailand and Vietnam, a common feature for both countries is that government policies promote the migration of rural labor to facilitate growth in the industrial and service sectors. Furthermore, policymakers in both countries have the vision to transform their agriculture towards large-scale farming, following the model of western agriculture. While out-migration from rural areas has taken place and the share in off- and non-farm income in total household income has been growing, the share of agriculture income in many cases is now less than 50 %. To date, labor rather than land (as in the past) is the main income-generating factor. However, agriculture still plays an essential role in the rural areas of these two countries. Farms are still small, and farm sizes almost remained the same over the past decades. Structural transformation of the rural areas as envisaged by policymakers does not take place. Households keep their agriculture as a backup and safety net and hence small-scale farming continues to dominate. At the same time, farmers in the two regions are increasingly exposed to severe weather events caused by climate change which makes them vulnerable to poverty and food insecurity (ADB, 2009; IPCC, 2014a; Blanc & Reilly, 2017). In this study, it is therefore aimed to obtain a better understanding of farmers' decision-making in agriculture. In particular, the thesis aims to investigate how farmer knowledge and skills and their risk attitudes, on the one hand, and the increasingly occurring extreme weather events, on the other hand, influence their decision-making with regard to farm management decisions. There are three specific research questions to be answered in this research: (1) how do risk attitudes affect household decision-making; (2) what is the impact of agricultural knowledge on agricultural production; (3) how do farmers manage their agricultural inputs in response to extreme weather events. To answer these questions, the thesis draws on two primary data sources. The first is the database of the Thailand Vietnam Socio Economic Panel (TVSEP) project during the period of 2007 to 2017, i.e., six-year panel dataset was collected from some 4,400 rural households in the Northeastern Thailand provinces of Nakhon Phanom, Ubon Ratchathani, and Buri Ram; and in Vietnam’s Central Coastal and Central Highlands provinces of Ha Tinh, Thua Thien Hue (Hue), and Dak Lak. The second data source is historical weather data. We use the monthly high-resolution (0.5) temperature and precipitation data observed from 1948 until 2016 from the Global Precipitation Climatology Centre (GPCC; Schneider et al., 2018), and the Global Historical Climatology Network Monthly - Version 2 and the Climate Anomaly Monitoring System (GHCN + CAMS; Fan & Dool, 2008), respectively. The results of the thesis are presented in three essays. The first essay is “Risk attitudes and implication for livelihoods strategy – evidence from two provinces in Thailand and Vietnam.” Utilizing an Ordinary Least Square (OLS) and a Probit regression with different alternative specifications, the determinants of risk preference for household decision-making are analyzed. Results show that risk attitudes are significantly related to individual characteristics such as age, gender, height, and household wealth. There are correlations between the willingness to take risk and real-life decisions of farm households. The findings show that risk-seeking individuals likely diversify income-generating activities as a cushion against the risk of small-scale farmers in these areas. They invest in self-employment and other non-farm enterprises while still capitalizing in agriculture. The second essay, named “Farmers’ knowledge and farm productivity in rural Thailand and Vietnam”, investigates the relationship between farmers’ knowledge, skills, and agricultural productivity. This paper uses primary data on agricultural knowledge and skill tests among “TVSEP households” in the provinces of Ubon Ratchathani in Thailand and Hue in Vietnam. A Two-Stage Least Squares (2SLS) approach combining knowledge and skills test results with productivity data of later waves was developed to identify the effects of agricultural knowledge and skills on agricultural productivity. The major finding is that technical knowledge in agriculture is significantly and positively associated with profit but significantly negative with rice yields and cost of input costs. This suggests that knowledgeable farmers may strive for optimal rather than maximum yield and are more judicious in the use of inputs which is good for the economy and the environment. In the third essay, named “Extreme weather and agricultural input management in rural Thailand and Vietnam: Intensify or de-intensify?” we investigate the impact of extreme weather events, namely drought, on household input management decisions in Northeastern Thailand and Central Vietnam. Eight inputs are captured: land, labor (household labor and hired labor), chemicals (i.e., fertilizer and pesticides), irrigation, machinery, and other agricultural investments. We define two binary drought indicators, namely severe drought and extreme drought, using the Standardized Precipitation Evapotranspiration Index (SPEI) as the criterion. We then use Fixed Effects (FE) model for this paper’s purpose. Results indicate that farmers tend to de-intensify agricultural production in terms of hired labor, pesticides, number of crops grown, and agricultural investments in response to severe droughts. Second, farmers increasingly hire machinery as a substitute for owned equipment and for household labor. Third, the magnitude of the effects increases with the severity of drought. Differentiating the analysis between countries, and upland versus lowland rice production, shows that the level of de-intensification varies. For example, Thai farmers allocate more family and hired labor to agricultural production; Vietnamese farmers invest in agricultural assets. Upland rice farmers focus on several inputs such as pesticides, machinery, and agricultural assets, while lowland farmers focus on available irrigation systems. All three essays have generated important policy messages for Governments in both countries to consider public support measures to strengthen rural households coping strategies toward extreme weather events and climate change

Allelic polymorphism of crtRB1 and LcyE genes related to the β-carotene content in Vietnamese traditional maize accessions,

Maize is the third most important food crop after wheat and rice. Maize is used as food for more than a billion people around the world and is used as animal feed, especially, poultry. The concentration of carotenoids, especially, β-carotene in maize grains, is very low. Therefore, the study of increasing the amount of provitamin A carotenoids including β-carotene is important. In maize, different alleles of crtRB1 and LcyE genes have a significant effect on β-carotene content. In this paper, we present the results of the study of allele polymorphism of these two genes related to the provitamin A carotenoid content in some traditional maize accessions collected from several regions in North and Central Highlands of Vietnam. The results showed that there were polymorphisms at the 3’ and 5’ ends of the crtRB1 and LcyE genes. Among 22 maize accessions, the proportion of favorable alleles at the 3’ end of crtRB1 gene was relatively high (5/22 = 22.73%). Similar results were obtained for alleles at 3’ end of the LcyE gene. Especially, there is an accession (Northern white gold maize) that carries favorable alleles at the 3’ ends of both crtRB1 and LcyE genes. While all investigated maize accessions did not carry favorable alleles at the 5’ end of both crtRB1 and LcyE genes. The identification of traditional maize accessions that carry favorable alleles for increasing b-carotene content opens up potential to exploit indigenous genetic resources for genetic research as well as to develop maize varieties with high β- carotene content.

EVALUATING FUTURE WATER QUALITY OF URBAN RIVERS IN HANOI UNDER EFFECT OF URBANIZATION AND CLIMATE CHANGE - THE APPLICATION OF WEAP MODEL FOR CAU BAY RIVER

Every day, up to 750,000 cubic meters of wastewater in Hanoi metropolitan areas is discharged directly into rivers and lake, of which only 10% is treated to the Vietnamese standards. According to the water drainage development master plan for the capital city of Hanoi until 2030, the government aim at dealing with flooding and improve environmental sanitation for local residents. With respect to the baseline and Master plan implementation scenarios, this study evaluates the future water quality of urban rivers in Hanoi under the effect of urbanization and climate change using Water Evaluation And Planning tool (WEAP) and take the Cau Bay catchment as the case study. The result shows that, without implementation of wastewater treatment plant, the water quality of Cau Bay River will be worse with the DO in dry season is 0.2-1.2 mg/l and BOD is 52.0-55.0 mg/l. With the implementation of Master plan, the level of DO and BOD would be 7.1-7.3 mg/l and 7.0-13.8 mg/l respectively in the dry season whereas the values are 3.7 mgO/l and 36.1-41.8 mg/l in the wet season. The degradation of wastewater during the wet season is results from the combine- overflow sewage system as designed in the master plan

Systematic coarse-graining and dynamical simulations of anisotropic molecules with applications in organic semiconductors

Organic semiconductors are used widely in different applications, including organic photovoltaics (OPVs), devices that convert solar energy to electricity. These devices, if applicable commercially, can help to supply the world’s energy needs without requiring complicated manufacturing and maintenance. Moreover, OPVs possess several useful physical properties such as being light weight, highly transparent, and flexible. This makes organic electronic devices advantageous over those made of inorganic hard materials, especially in applications in which these conditions are required. Although experimental studies show that organic semiconductors can potentially yield high performing devices, the electronic processes that govern the conversion of light to energy are not fully understood. Specifically, how free electrons are created and transferred within the device when a photon is absorbed is strongly debated in the literature. Many experimental and theoretical results have shown that microstructure at the interfaces between the component organic semiconductor materials that make up the device plays an important role in these processes. The microstructure can be induced by directional forces between generally anisotropic organic-semiconductor molecules, combined with translational symmetry breaking at interfaces. In Chapter 3, the interface of a high-performing electron donor–acceptor OPV system consisting of two small organic semiconductors benzodithiophene quaterthiophene rhodanine (BQR) and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) is studied using classical molecular dynamics (MD). Atomistic simulations at high temperatures indicate that the "face-on" configuration is more favorable at a liquid–solid interface between the materials. In addition, molecules close to the interface are less ordered with respect to one another than those far from the interface. These factors may benefit charge separation and transport, resulting in good device performance. In general, atomistic simulations are not feasible for studying donor–acceptor interface formation for the typical domain sizes found in devices. A solution to this is to use coarsegrained (CG) models, which increases the simulation efficiency by replacing a collection of atoms as a single interacting site. In Chapter 4, a new systematic methodology to generate CG models for MD simulations is introduced and validated, which constitutes the main result of this thesis. This algorithm is developed so that MD simulations can be simplified but still accurately represent the physical and thermodynamic properties of the simulated materials. More importantly, this method can produce models that capture the anisotropy of molecules, which is especially useful for theoretical studies of organic materials and has not previously been achieved via a systematic algorithm. To validate the method, a CG model of a simple anisotropic organic molecule (benzene) is produced in Chapter 5. Simulations using this model accurately describes the structural and thermodynamic properties of the FG model and is an improvement over previous CG benzene models. A future application of this method will be the study of the interface structure of materials in OPV systems on realistic time and spatial scales compared to experimental conditions. Ultimately, the studies presented in this thesis work towards the same goal, which is to discover optimal molecular design rules to increase the power conversion efficiency of OPVs.Thesis (MPhil) -- University of Adelaide, School of Physical Sciences, 201

ベトナムにおける再生可能エネルギーと分散型排水処理の組み合わせによる低炭素型流域管理方法の提案

学位の種別: 課程博士審査委員会委員 : （主査）東京大学教授 福士 謙介, 東京大学教授 味埜 俊, 東京大学特任准教授 松田 浩敬, 東京大学准教授 小貫 元治, 東京大学客員教授 竹本 和彦University of Tokyo(東京大学

Discuss the Selection of Research Variables in Applying Gravity Model to Analyze Factors Affecting Specific Sector

Gravity model is an important tool for researchers interested in the impact of trade-related policies. It provides a relatively accurate result for testing and evaluating the trade-impact of various policies. In recent years, the application of the model in research has become a trend in many countries around the world, including Vietnam. Though it is considered an attractive platform for international trade researchers, its use is not without potential pitfalls. The most important thing for the application of this model is the choice of exactly which model to estimate (Sherpherd, 2019). This paper aims to systematize the development process, analyze the nature of the model, and focus on analyzing its applicability in the study of trade flows for a specific sector. Based on that, it gives some comments and evaluation on the selection of research variables in a number of recent studies which apply this model in analyzing factors affecting exports of a specific sector in Vietnam. Finally, it draws some conclusions and recommendations for the application of this model in research. Keywords: Gravity model, Structural gravity model, Theoretical foundation, Nature DOI: 10.7176/EJBM/13-10-05 Publication date:May 31st 202