The diamondback moth (Plutella xylostella) is one of the most destructive pests of cruciferous vegetables in the Mekong delta of Vietnam. In order to application of sex pheromones as tool for a sustainable management program, the sex pheromone components of P. Xylostella, (Z)-11-hexadecenal (Z11-16:Ald), (Z)-11-hexadecenyl acetate (Z11-16:OAc) and (Z)-11-hexadecen-1-ol (Z11-16:OH), were synthesized and evaluated their attraction in field. The synthetic route using Wittig reaction as key reaction successfully synthesized Z11-16:OH and its corresponding Z11-16:Ald and Z11-16:OAc compounds. After protecting the hydroxyl group of 11-bromo-1-undecanol by methoxymethoxy (MOM) ether, the protected compound was heated with triphenylphosphine at 100oC 24 hrs. to form a phosphonium salt which was converted to MOM ether of (Z)-11-hexadecen-1-ol compound by coupling with pentanal under the catalyst of sodium bis(trimethylsilyl)amide solution in THF (Wittig reaction). Stirring of the MOM ether compound in 0.5N HCl solution in methanol 24 hrs. to remove hydroxyl protection obtained Z11-16:OH compound (isomeric purity was >96% as checked by GC-MS analysis). Yield of the synthetic route (from 11-bromo-1-undecanol to Z11-16:OH) was 42.9%. Following, PCC oxidation and acetylation of Z11-16:OH gave Z11-16:Ald and Z11-16:OAc, respectively. In field examinations, traps baited with synthetic lures prepared from different mixtures of Z11-16:Ald, Z11-16:OAc and Z11-16:OH caught significantly higher number of P. xylostella males than that of control affirming the attractiveness of synthetic pheromones. However, only the attraction of three components lures were as strong as that of a virgin female. Otherwise, only traps baited with two components lures prepared from Z11-16:Ald and Z11-16:OAc caught more P. xylostella males than those of traps baited with single component lures. These indicated that Z11-16:Ald and Z11-16:OAc were actively obligated components while Z11-16:OH was a syergistic component for the attraction of P. xylostella in the Mekong delta of Vietnam.

This study was aimed to investigate the effect of Uniconazole (UCZ), as a replacement for Paclobutrazol (PBZ), on flowering of ‘Dai Loan’ mango, and to determine suitable UCZ dosages and the periods for bud break. Experiments were conducted on 7-year-old trees arranged in completely randomized design with two factors, i.e. dosages of bud initiation agents, and periods for bud break. For the former factor, the three dosages of UCZ included 1, 1.5 and 2.0 g a.i. m-1 canopy diameter, and a positive control (PBZ at 1.5 g a.i. m-1 canopy diameter). The second factor comprised three periods for bud break after bud initiation applications, viz. 45, 60, and 75 days (DABIT). All treatments were repeated six times, each of which equalled to one tree. Results suggested that UCZ can definitely replace PBZ in regard to its effects on the flowering. Flowering ratio reached to the highest, 85.5 – 90.0% when UCZ was applied at 1.5 – 2.0 g a.i. m-1 canopy diameter, and subsequently followed by bud break treatment with KNO3 2.5% at 75 DABIT. In addition, inflorescence length was not different between PBZ and UCZ dosages, while UCZ 1.5 and 2.0 g a.i. treatment brought about higher number of hermaphrodite flowers per inflorescence. Furthermore, application of either PBZ or UCZ at 1.5 g a.i. m-1 canopy diameter combined with bud breaking treatment at 75 DABIT, resulted in the highest yield, i.e. 40.8 and 50.3 kg/tree, respectively. As for the characteristics and quality of fruit, neither the two investigated factors caused significant impact.

The present study aimed at evaluating the impact of the National Target Program on New Rural Development on the household income in Go Quao district, Kien Giang province where had been selected as a pilot site of the program in the province since 2010. Data in the analysis came from a survey on 194 households at study site. The survey was conducted in 2015 to collect the retrospective data on the income of households and socio-economic characteristics of households and communities from 2010 to 2014. Then, the Difference in Differences (DiD) estimator associated with the random effects model were applied to explore the impact as well as the determinants of household income. Estimation results showed that the impact was positive and significant in the first year but turns to insignificant afterwards. The household income is increasing during 2011 – 2013 and mainly dependent on the transportation infrastructure of the community and the participation in agricultural cooperatives. In addition, since household income mainly came from agricultural production, labor and landholding were also key predictors of income.

Superparamagnetic copper ferrite nanoparticles were utilized as a recyclable heterogeneous catalyst for the cross-dehydrogenative coupling of N,N-disubstituted formamides with phenols. This routine allowed the creation of a hybrid benzothiazole-carbamate moiety under heterogeneous catalysis. These products possess both carbamate and benzothiazole moieties, thus taking profits from both structures with regard to pharmaceutical  and biological and activities.  Employing a catalytic portion of thesuperparamagneticnanoparticles, hybrid benzothiazole-carbamate structures could be produced with reasonable yields within 2 h. It was  possible to recover the nanoparticles by simple magnetic separation, and reutilize them for the reaction without a significant decline in catalytic efficiency. 

In this study, the three-factor rheology model was applied to simulate land subsidence associated to the groundwater decline in the urban area (Can Tho) and the coastal area (Soc Trang) of the Mekong Delta (of Viet Nam). The considered three factors are: (1) the elasticity coefficient; (2) the viscosity coefficient of the Voigt part; and (3) the viscosity coefficient of the Damper part, were calibrated to get the matching with limited observed values. As the results, the long-term transient simulation in the period of 2000-2013 showed the land subsidence rate in Can Tho city was around 2.6 cm/year. For the coastal area, transient simulation showed the cumulated subsidence for the period of 1994-2014 was 65 cm which means around 3 cm per year. To maintain the groundwater pumping under future rainfall condition, another 60 cm of land subsidence was expected over the next 21 years in the coastal area. To understand the subsidence under increase in pumping (1.8% per year), the cumulative land subsidence in the period of 2014-2035 was estimated around 71.4 cm at the coastal area of Mekong Delta.

With the growing popularity of English-as-a-medium-of-instruction (EMI) all over the world, the issue of how to best prepare non-native students for their language-related problems in EMI courses also arises. While a number of studies have shed critical light on problems students encounter in EMI courses, very few have explored how students should be supported to overcome these challenges.  The current study investigated such an effort in a university in Vietnam where an English foundation program (EFP) of 390 hours have been designed and implemented for one semester before students begin their EMI courses. In particular, the study seeks to figure out the structure of the English Foundation Program (EFP) and students’ evaluation of its usefulness for their EMI courses. The findings from the current study is expected to provide the EFP designers with a basis to (further improve) revise their program and to help other institutions which are implementing EMI have an idea of what should be done to support their students better.

This article reports a part of the bachelor graduation thesis (the academic year 2017) on the extent to which Can Tho University’s (CTU) English Interpretation and Translation (EIT) majored seniors can translate printed informative advertisements from English into Vietnamese. The purpose of the article was to rank the linguistic difficulties, particularly lexical and grammatical ones, that EIT majored seniors faced in advertising translation and identify the strategies they applied to overcome such challenges. Forty-one EIT majored seniors, Course 39 of CTU, were asked to translate two printed informative advertisements from English into Vietnamese within 90 minutes. The findings showed that regarding linguistic difficulties in translation, vocabulary was more problematic than grammar. In terms of translation strategies, the students used Equivalence to deal with Polysemy; Paraphrasing with Terminology and Idiom; Addition with Proper Noun and Imperative Mood; Borrowing with Proper Noun; Transposition with Passive Voice and Noun Phrase; and Reduction with Plural Noun. They did not, however, apply Word-for-word Translation to solve any difficulties in question. The results of this study could help students be aware of their professional knowledge and skills so that they can employ appropriate ways of translation learning and practicing and be well-prepared to work as translators, especially in the field of advertising translation.

Along with the demand of global integration, learning foreign languages for international communication has become more and more vital between Vietnamese and foreigners. Therefore, English speaking skills is an indispensable course in English language curriculum at tertiary level. However, it is not easy for English learners in this context to achieve their fluency and proficiency in English speaking skill due to certain internal and external factors. Therefore this study is to investigate challenges of speaking skills faced by English-majored freshmen in a Vietnamese university. The data obtained from the survey questionnaires with 131 students, individual interviews with lecturers, and class observation. The findings show that English freshmen faced both internal and external challenges, especially the latter ones regarding the limitation of English speaking environment and extracurricular activities. Possible measures are proposed to tackle such challenges in helping students speak English more effectively.

 The study was conducted to assess the possible utilization of protein extracted from green seaweed (Cladophoraceae) in mudskipper (Pseudapocryptes elongatus) diets. The fishmeal (FM) protein was replaced by protein extracted from green seaweed (EGW) at graded levels of 15, 30, 45 and 60%. The diet without green seaweed protein considered as a control treatment. All experimental feeds were formulated to be equivalent in crude protein (30%) and lipid (7%). Fish with average initial weight of 0.43 g were reared in the 100-L tank at a density of 30 fish per tank and salinity of 10 ppt, fed ad libitum twice a day. After 45 days of feeding trial, survival of experimental fish was not affected by the feeding treatments, varied in the ranges of 91.1- 94.4%. When fishmeal protein was replaced from 15% to 45% of protein extracted in the diets, growth rate of fish were better or similar to those in the control diet. Although feed conversion ratio (FCR) increased and protein efficiency ratio decreased with increasing levels of FM substitution from 30% upwards, statistical differences were not observed among feeding treatments. The proximate composition of fish fillet such as the moisture, lipid, and ash contents tended to decrease with increasing level of EGW protein while the protein contents slightly increased at higher inclusion of EGW protein in the diet from 15% to 45%. The present study indicated that protein extracted from green seaweed (Cladophoraceae) could replace fishmeal protein up to level of 45% in formulated feed for the mud skipper (P. elongatus) diets.

The data of the project: “Research on fluctuations and distributions of fishing effort in the South-East offshore Waters of Vietnam” was used to analysis fishing effort and stock biomass status of trawler activities in the South-East offshore waters. The results showed that fishing effort and stock biomass of trawlers group over 250 hp power were overfished maximum sustainable level. The trawlers of 90 to 249 hp showed two diffirence periods: The stage before 2010, stock biomass was overfished but fishing effort was not overfished. Otherwise, the stage after 2010, both fishing effort and stock biomass were overfished maximum sustainable level and trended to increase rapidly. For trawlers group under 90 hp, fishing effort had not been overfished but stock biomass crossed the threshold. In general, fishing status of all of trawls trend to deeply overfished both sides of fishing effort and stock biomass, the reducing number of trawler is recommended to remain sustainable stock biomass in the South-East offshore Waters. Kobe Plot chart was used to assess fishing effort and stock biomass actuality of the survey years compare to maximum sustainable threshold and trend its fluctuation. There are important results for reference point to support managers issue decisions for fishing effort controlling to maintain and develop marine fish resource in the South – East Offshore Waters.

Abstract. Actinomycetes are filamentous gram-positive bacteria that can be found abundantly in both terrestrial and marine environment. These bacteria are known as producers of many bioactive compounds through the production of secondary metabolites for their survival and adaptation in nature and have been widely used today as therapeutic agents. Marine actinomycetes have been the focus of research over the past decade for new drugs discovery due to its unique adaptation in the harsh sea environment. It is believed that marine actinomycetes could produce compounds that are rare and unique compared to the terrestrial actinomycetes. Marine sponges often harbor dense and diverse microbial communities including actinobacteria. One secondary metabolite, thymine was isolated and identified from marine Streptomyces sp. strain ND7c. Its structure was determined by spectroscopic analysis including MS and 2D NMR, as well as by comparison with reported data in the literature. Keywords. Marine microorganism, secondary metabolite, marine sponges, Streptomyces sp., thymine

Given a ground set of n elements with associated positive weights and a class of its subsets, also known as feasible solutions. In the setting of the original combinatorial optimization problem, each feasible solution corresponds to an objective value, often measured under the sum or the max of all element weights in the underlying solution. We address in this paper the problem of modifying the weight of elements in the ground set such that a prespecified subset becomes the k-th maximizer with respect to new weights and the cost is minimized. This problem is called the inverse version of the k-th maximization combinatorial optimization. We propose two quadratic that solve this problem with sum objective function under Chebyshev norm and the bottleneck Hamming distance. Additionally, if the objective function is the max function then this problem can be solved in O(n^2 logn) time.

Derivatives of 1,4-dihydropyridines are well known as calcium channel modulators for the treatment of cardiovascular disorders. Herein, three 1,4-dihydropyridines were synthesized through the condensation of an aldehyde, a β-ketoester, and ammonium acetate in ethanol with yields ranging from 23 to 59%. Their structures were confirmed by comparison HRMS, NMR spectral data with the literature. The acute oral toxicity study for the synthesized compounds revealed that all compounds were safe up to 2000 mg/kg and no deaths of animals were recorded. 

Galactose biosensor based on ZnO nanorods were fabricated and modified through the addition of Au nanoparticles. The sol-gel method was utilized to grow ZnO nanorods on indium tin oxide-coated glass substrates (FTO) and the the Au nanoparticles were modified on ZnO nanorods by hydrothermal method. Well aligned hexagonal structured ZnO nanorods with a diameter from 40 to 60 nm were obtained. The Au nanoparticles (Au NPs) were spheres and they had diameter from 6 to 8 nm. After these Au NPs were attached to ZnO nanorods electrode, galactose oxidase enzyme (GOx) was immobilized on this electrode in 3.5 hours to form the working electrode in galactose biosensor (GOx|Au-ZnO|FTO). The cyclic voltammetry method (CV) was used to test the activity of the working electrode in galactose solution 200 mM concentration. The CV result showed that the current intensity of the GOx|ZnO|FTO electrode in galactose solution is about 0.085 µA/mm2. On the other hand, with the  GOx|Au-ZnO|FTO electrode, this value increases to 0.2 µA/mm2.

ABSTRACTThe present research is aimed at investigating the effect of Task-Based Language Teaching (TBLT) on learner writing performance and learner writing motivation which is considered a mediating variable in enhancing writing performance of EFL learners at Tien Giang University. The quasi-experimental design was employed with the participation of 40 freshmen equally split into the control group (CG) and experimental group (EG). The analysis of the data collected from the participants’ pretests and posttests, pre-questionnaires and post-questionnaires indicated that TBLT positively influenced EFL learners’ writing performance with significant improvement of all five components namely vocabulary, content, grammar, organization and mechanics. In addition, it revealed that there was a positive influence of TBLT on learner writing motivation and a positive correlation between learner writing motivation and writing performance.Key words: Task-Based Language Teaching (TBLT), writing performance, learner writing motivation