From native peat samples collected from U Minh peatlands, modified peat samples were prepared by treating with 5% HCl solution. Their physico-chemical properties and adsorption abilities for Cu2+ and Pb2+ ions were investigated. The results showed that U Minh peat samples had high humic acid content, low ash content, pHZCP and porosity. The Cu2+ and Pb2+ adsorption capacities of modified peat samples were higher than that of native ones.

Silicon is an abundant element in the earth crust and has been used widely in industry. Recently, there have been many evidences showing that silicon has versatile functions in plant growth, development, and yield, particularly in enhancement of plant tolerance to biotic and abiotic stress. In this study, silicon in the form of sodium silicate was added to the growing solution to examine possible contributions of silicon to the tolerance of OM4900 rice seedlings exposed to saline condition. The growth of rice seedlings were inhibited when increasing NaCl concentration or exposure time to saline environment. From the salinity dose of 3 g/L, proline level in rice seedlings increased sharply. Under 4? NaCl condition, addition of sodium silicate has no clear enhancement of rice seedlings? tolerance both in growth of root and shoot or relevant metabolites such as proline or total soluble sugars. The tolerant ability to salinity of popular growing rice cultivars are quite difference and the root growth inhibition was easily to observe. It is needed to test other silicon containing compounds under lower saline doses than 4? to enhance the rice tolerance to salinity.

This research aims at identifying factors affected the effectiveness of business performance of small and medium sized enterprises (SMEs) in Can Tho city. The sample size of 389 collected from SMEs in Can Tho city. Descriptive analysis and regression analysis used in this research. The results of the study showed that factors of access to governmental supporting policies, years in schooling of businessmen, scale of company, social relations, and revenue impacted the effectiveness of business activities of SMEs in Can Tho city.

The main objectives of this research were to test the effects of storage time after harvesting and the distillation time on the yield of ginger oil. Further investigation was carried out to evaluate the chemical, physical properties as well as sensory characteristics of ginger oils which were extracted by conventional hydrodistillation and microwave-assisted hydrodistillation. The results showed that the storage time of ginger rhizomes should be within 4 days before distillation. The total time of distillation was 16 hours and only 80 minutes at 300W, respectively. Moreover, not only the quality of ginger oils but also the type of components in the essential oils were moderately dependent on the hydrodistillation methods. The major compounds in ginger oils from both such hydrodistillation ways consisted of Neral (13,99-24,04%), Zingiberene (10,62-10,88%), alpha-Farnesene (7,3-8,05%), Nerol (6-7,09%) and beta- Sesquiphellandrene (5,31-5,37%).

The present study was conducted to evaluate the fermentation efficiency of isolated locally identified yeast strains against the commercial yeast preparations in the case of palm wine. The impact of isolated yeast cell number varied from 101-106 CFU/ml, soluble solid contents and pH values ranged 20-24oBx and 3.5 to 4.5 (respectively) were studied. The quality of fermented wine produced from isolated was compared to wine fermented from the commercial yeast. After fermentation for 12 days, isolated Saccharomyces had all of the desired properties for the purpose of this study and fermented alcohol better than commercial wine yeasts. The highest of 13.67% (v/v) and lower 12.33% (v/v) alcohol concentrations with corresponding residual sugar concentrations of 2.57% (w/v) and 3.42% (w/v) were produced from palm wine (pH 4.0 and 24oBrix) with isolated yeast strain (103 CFU/ml) and commercial yeast, respectively. The chemical properties of wine (volatile acid, ester, sulfur dioxide and methanol content) were less than permitted levels of Vietnamese standard.

Our investigation aims at classifying spam emails based on machine learning algorithms. The representation of the email that we use for classification is the bag-of-words model, which is constructed from the counting the word occurrence in a histogram like fashion. The pre-processing step brings out a dataset with a very large number of dimensions. Thus, we propose a new algorithm boosting of random oblique decision stumps that is usually suited for classifying very-high-dimensional datasets. The numerical test results on a real dataset collected from 1143 spam and 778 non-spam emails showed that our algorithm boosting of random oblique decision stumps outperforms support vector machine (SVM) and Naùve Bayes in terms of Accuracy, F1-Measure, Precision, TP Rate and TN Rate.

Applying electrophoresis technology SDS-PAGE protein process (Japan Department of Agriculture 1996) to analyze and select original rice varieties which were collecting from local area and crossed stock. Then experiment was researched at summer-autumn crop in experiment farm of Can Tho University and was arranged according to Randomized Complete Block Design with 3 repeating times, 11 real roots which are 11 rice breeds: TPCT1, TPCT2, TPCT6, Jasmine 01, Jasmine 08, Jasmine 10, VĐ20-03, VĐ20-07, VĐ20-17, VĐ20-17 and Jasmine85 as control breed. The result is that all experiment breeds have aroma, short growing time (under 100 days), low pestilent insect, higher productivity than the control breed, having thin long rice, good quality rice, meeting the planed goal.

From the petroleum ether extracts of the roots of Areca catechu L., collected in Phong Dien district, Can Tho city, we have isolated two compounds: lupeol (C30H50O) and lupeol acetate (C32H52O2). The structures of these compounds have been elucidated by modern spectroscopic methods: MS, 1H-NMR, 13C-NMR, HSQC, COSY and HMBC.

Top soil removal in rice fields has been enlarged in theMekongdelta. The explanation for this activity was due difficulty in irrigation for rice if the field was high elevation. In addition, by selling the top soil, farmers can earn little money for their family. Questions have been arise whether soil quality changes and rice yield declined when top soil lost. The aim of this study was to evaluate the affect of top soil removal on soil properties and rice yield. Soil samples and rice yield were collected in Chau Thanh district, Tra Vinh province in areas where topsoil was removed in comparision to topsoil remaining. Soil samples were analyzed some soil physio-chemical and biological properties. The results showed that there was a trend in reducing soil organic matter and biological activities in the field of topsoil removal, and a significant decrease in available phosphorus and soil aggregate stability. Meanwhile, soil pH, base saturation and soil bulk density had no remarkable changes. Although, soil quality showed a trend in decreasing, rice plant growth and rice yield had a significant decrease compare with non-affected soil. Therefore, the removal of topsoil led to reduce significantly plant biomass, rice yield and soil quality in long-term.    

In vitro activities of Bronopol (B), hydrogen peroxide (HP), Formalin (F) and Sodium Hypochlorite (SH) against hyphal growth and conidia of P. oratosquillae NJM0662 and Acremonium sp. NJM0672 were examined. As a result, hyphal growth of the isolates NJM0662 and NJM0672 were strongly resistant to SH, and the MICs were 800 and 1600 ppm, respectively. The MICs of B, F and HP against hyphal growth and conidia of both isolates were 50, 200 and 400 ppm, respectively. MFCs of B, F and HP against hyphal growth and conidia of the isolate NJM0662 were 50, 150 and 400 and 50, 200 and 800 ppm, respectively, when exposed to the chemicals for 24h. While MFCs of B, F and HP on hyphal growth and conidia of the isolate NJM0672 were 50, 150 and 300 and 800, 400 and >1600 ppm, when exposed for 24h, respectively. As a result, it was concluded that B and HP were effective chemicals in this study. On the other hand, in vitro antifungal activities of fluconazole, amphotericin B, 5-fluorocytocine, terbinafine hydrochloride, micafungi, voriconazole, miconazole and itraconazole against these species showed that amphotericin B, voriconazole and terbinafine hydrochloride were effective both the isolates.

Information technology was applied to evaluate the physical land suitability at a district level (Mỹ Tú district). The aim of study was to evaluate the ability of the Automated Land Evaluation System (ALES) software for land resources management and sustainable agricultural development. The results showed that the ALES and PRIMER softwares can be applied for land evaluation, in which selected suitability zones following the natural conditions that included different LUTs. Using of the?Hierarchical cluster? function of the PRIMER softwares follow similarity land mapping units of LUTs and use modules ALIDRIS of the IDRISI software was created the land suitability map for every LUT. With the application of the multi-objectives approach which includes natural, economic, social and environmental conditions, the studied LUTs was ranked according to the level of suitability (ranging from high to low): specializing upland crops, specializing fruit trees, Double rice - upland crop, triple rice, specializing sugar-can, rice-shrimp. The results showed that the ALES and PRIMER software can be applied for land evaluation with multi-objectives of natural, economic, social and environmental conditions, which satisfies the multi-purposes and sustainable land use planning.

In this paper, we investigate a learning to rank model called C4.4-kNN for searching experts. This model is based on the bag of words model and also uses the C4.4 algorithm (well-known as a good ranking algorithm) and the k nearest neighbors algorithm (considered as the simplest instance-based learning). In addition, the model also takes into account user-relevance-feedback to improve ranking tasks. The numerical test results on the French speaking data mining conference (EGC) showed that our C4.4-kNN is better than kNN for the assignment task. C4.4-kNN proposes appropriate program committee members for a given paper abstract after a few of clickthrough experts.

This study was carried out to evaluate effect of the best endophytic Burkholderia strains together with compost from pineapple wastes for making bio-compost plus inorganic introgen fertilizer levels (0, 75 and 150 kg N/ha) to pineapple cultivated on acid sulfate soil of Hung Thanh village, Tan Phuoc district, Tien Giang province during two years (2008-2009). The results showed that the bio-compost compost plus 150 kg N/ha treatment improved yield component, pineapple yield, quality fruit and nutrient content in soil of bio-compost did not differ with pineapple applying of 300 kg N/ha treatment. The bio-compost not only maked a bio-layer to keep moisture but also limited toxicity of acid sulfate soil but also was a kind of good fertilizer for pineapple cultivation which saved 50% chemical nitrogen fertilizer and improved fruit yield. 

?Value chain analysis of rice product in the Mekong Delta? based on an integrated approach of Kaplinsky and Morris (2000), Recklies (2001), GTZ ValueLinks (2007) and M4P (2007) along with direct interviews of 564 individual chain actors and 10 groups of rice farmers in the four research provinces. Research results consist of (1) Analysis of present rice value chain including domestic rice value chain and export rice value chain, (2) Chain economic analysis includes production cost, cost-added, value added, net value added (profit), chain income of each actor and the entire chain, (3) Analysis of risks, risk management and policy issues of the rice chain, (4) SWOT analysis focuses on strengths, weaknesses, opportunities and threats as well as examines rice chain quality problems. Finally, chain upgrading strategies of rice product are developed to improve chain value added, profit, income, competitive advantage and rice chain sustainable development in the Mekong Delta particularly and in Vietnam generally.

From the chloroform and ethyl acetate extracts, we have isolated and identified four compounds: stigmasterol, the mixture of stigmasterol and spinasterol with the ratio of 1:3,  sitosterol 3-b-O-D-glucopyranoside and quercetin 3-O-b-D-galactopyranoside. Their structures were evaluated by spectrum data of MS, 1H, 13C, DEPT NMR and 2D-NMR.

Effects of cypermethrin on mortality, surfacing frequency and growth of Climbing perch (Anabas testudineus) were carried out in laboratory. Acute toxicity test was done in static non-renewable system. Effects of sub-acute concentrations on surfacing frequency were designed as completely randomized block in glass aquaria. Behaviors of fish were continuously recorded during 90 minutes using video recorder (Sony, Japan). Growth experiment was conducted in 600 liter fiber-glass tank. Fishes were exposed to sub-acute concentrations for 4 days, then exchanged 30% of tank water and fed with commercial pellets everyday at approximately 5% fish weight. At day 15after experimentation, fish were exposed to Cypermethrin again as same as procedure in the first exposure. Results showed that Cypermethrin was very toxic to perch, with a 96h- LC50 of 23àg/L. Surfacing frequency increased significantly to control. At concentration of 0.2 and 5.8àg/L, surfacing frequency increase 1.7 and 2.4 times of control, respectively. Specific growth rate, feed conversion ratio were not significant effects. Using Cypermethrin for rice may cause direct mortality for the perch. Monitoring Cypermethrin on soil and water in rice-field and effects on the species is highly recommended.

Stemming from the need to expand the growing rice area to Phu Tan district - An Giang province, and diversify to create the same delicious typical rice style. CK92 seed collected from this area, the purifying method and selected by SDS-PAGE approaching to high yield, good quality. The experiments including 2 pure lines were carried out two seasons (Winter Spring 2008-2009 and summer- Autumn 2009) by RCBD with three replications. Results showed that 1 elite lines was chosen. Yields ranged from 6.5 to 7.5 ton/ha, low amylose content 10%.

We consider parametric vector equilibrium problem in metric spaces. Sufficent conditions for the Hửlder calm continuity of the solutions are established. We also study the Hửlder well-posedness for vector equilibrium problem.

Research on the effects of salinity on growth and osmoregulation of Snakeskin gouramy (Trichogaster pectoralis Regan, 1910) fingerling stage was conducted at the College of Aquaculture and Fisheries, Can Tho University. The research including two experiments: (i) researching the effects of salinity on growth and (ii) the osmoregulation of Snakeskin gouramy fingerling stage. The results showed that in the first two week, growth of fish of control treatment was higher than other treatments (1.43g/fish) and significantly differences (p0.05) but significantly differences (p

This study presents a solution of natural lighting by using fiber optics to bring sunlight into house. An acrylic parabolic mirror with 640mm diameter is automatically controlled to track the sun for sunlight concentration. Focused sunlight is reflected by a 200mm diameter flat mirror back to the central bottom of the parabolic mirror to transfer into 150 optical fibers, which was tied as a 5m long bundle with 12.25mm diameter. The parabolic mirror was fixed in a steel stand for only moving in east-west direction. A PIC16F877A microcontroller observes sunlight sensors to generate control signal for motor driver to move the parabolic mirror with a speed of 3.33rpm. First step experimental result indicated that by using 640mm diameter parabolic mirror, the luminous flux of optical fibers output is only 600±50 Lm equivalent to a half of a 20W fluorescent lamp. However, the experimental result also showed that, system improvement to obtain a higher lighting power approximate to two 20W fluorescent lamps is feasibility, which can be carried out by replacing the flat mirror by a small parabolic mirror and enlarging the fiber optics bundle to 20mm diameter. Bringing parabolic mirror concentrated sunlight into house is a method to economize electric power and take full advantage of using infinite energy from sunlight.

Sugarcane has been cultivated long ago in acid sulfate soils and gave good profit for farmers in the Mekong delta. Information about effects of NPK fertilization on growth of sugarcane was still limited. The field experiment has been established in randomized complete Block Design, treatments consisted of fertilizer (NPK, PK, NK, NP) and  varieties (DLM24, ROC16, R570, QĐ11, CR74-250). The objective of this research was to use omission technique to evaluate the NPK supplying capacity and plant growth of different sugarcane varieties in Hau Giang acid sulfate soils. Applying of 300kgN/ha made yield of sugarcane increased 39-54% compared without N application, but P and K fertilization increased yield of sugarcane only around 10% compared without P and K application. However, K fertilzation made Brix in sugarcane increased. The yield of DLM24 was highest (140-145 t/ha) among five sugacane varieties. There is the need to determine sugarcane varieties which suitable for specific land area in order to get better yield and Brix.

This study aims to analyse factors that affect to tourist?s satisfaction with service quality in Kien Giang province. The data were collected from 295 respondents. Collected data were processed in the statistical software SPSS; the consistency coefficient measured with Cronbach?s Alpha for scaling test and Exploratory Factor Analysis (EFA) were used. The statistical results indicated important factors affecting level of tourists? satisfaction with service quality in Kien Giang including: ?well appointed room facility?; ?good transportation facility?; ?tourist guide?s behaviour?; ?tourist guide?s appearance? and ?tourism infrastructure?.

In this paper, we propose a new algorithm, called ArcX4-rODT (ArcX4 of random oblique decision trees) to classify gene data which have very small amount of samples in very high dimensions and noise. Our ArcX4-rODT algorithm constructs sequentially k random oblique trees so that each tree concentrates mostly on the errors produced by the previous ones. Furthermore, the hyper-plane obtained by Fisher's linear discriminant analysis is also used to perform multivariate splitting data at each internal node of the decision tree. Thus, the ArcX4-rODT can deal with very-high-dimensional data and noise. The experimental results on gene datasets from datam.i2r.a-star.edu.sg/datasets/krbd/ showed that our ArcX4-rODT algorithm outperforms randomforestofC4.5(RF-C4.5) and SVM (LibSVM).

This paper reviews the studies on using Artemia biomass as a food source for brackish aquaculture species. In experiment 1, supplementation of practical formulated feeds containing fresh or dried Artemia biomass for larval rearing of black tiger shrimp (Penaeus monodon) was assessed. Survival and growth data of postlarvae 15 indicated that feed containing Artemia biomass can partially replace commercial INVE feed as food supplement for larviculture of P. monodon. Experiment 2 was performed to evaluate the potential use of Artemia biomass, by-product from Artemia cyst production for nursing mudskipper (Pseudapocryptes elongatus) fingerlings; these results illustrate that both dried Artemia and Artemia based-feeds can be considered suitable feeds for mudskipper fingerlings. In experiment 3, using different forms of Artemia biomass as a food source for nursing mud crab (Scylla paramamosain) was examined. The results of survival and growth proved that live Artemia biomass is an ideal feed for nursery of mud crabs and frozen Artemia biomass may be an alternative in case of shortage or can be used for the hatcheries which are far away from Artemia culture sites. Detailed information on survival and growth in each experiment are discussed.

Reading comprehension is vitally important in yielding the productive outcomes for the language learners. Cognitive and metacognitive strategies have been strongly marking the positive evidences related to reading comprehension in tremendous studies (Phakiti, 2003; Lawrence, 2009; Quach, 2010). In this study, the three most frequently used cognitive ? metacognitive strategies in reading process responded by 196 Can Tho University English-majored students through the questionnaire have been discovered. Some pedagogical implications are finally pondered in Can Tho Univesity milieu.

This study was conducted from September 2010 to the end of December 2010 at Can Tho University. The participants were 80 third year students who were pursuing the Genaral English program for non-majors and 8 English teachers who teach in this program of Cần Thơ University. In this research, the independent variables are self-assessment and reflective activities in teaching and learning English, and dependent variable is communicative competence. In the research, the data were treated by SPSS (Norusis, 2000). It was found that the self-assessment and reflective practices were not effective at the classroom level (M= 1.73, SD=. 85). It was also found that the students almost seldom self-assessed (M= 4.18, SD= .70) and reflected (M= 4.24, SD= .80) on their English learning. From the results, the researchers propose that professional trainings of self-assessment and reflection in English language teaching and learning should be integrated into the curriculum.