Whitish gill and liver disease in fingerlings Pangasianodon catfish caused huge economic losses in commercial catfish in the Mekong Delta. The purpose of the study to determine haematological characteristics of 164 diseased fish obtained from 17 Pangasianodon farms. Bacteriological and parasitological characteristics were also checked. The result of haematological examination showed that there was significant decrease in the number of mature erythrocytes of diseased fish reduced extremely which constituted approximately 4,57% compared with healthy fish. Extraordinary forms of red blood cells, including the increase in the number of immature erythrocytes, cells without nucleus or two-nucleus were found. Moreover, leukocytes cells in diseased fish also decreased sifnificantly. Generally, leukocytes in diseased fish was seen significantly lower (P

30 medicinal plants in Mekong delta were tested antibacterial activity to determine the minimum inhibitory concentration (MIC) on Edwardsiella ictaluri, Edwardsiella tarda and Aeromonas hydrophila. The result showed that all tested medicinal plants had antibacterial activity (MIC=16-2048?g/ml). The greastest antibacterial activity against the experimented bacteria were Terminalia catappa, Psidium guajava, Piper betle and Melaleuca leucadendra (MIC=64-512 ?g/ml). The greastest antibacterial activity against Aeromonas hydrophila was Terminalia catappa (MIC=128 ?g/ml), against Edwardsiella ictaluri was Eleutherine bulbosa (MIC=16 ?g/ml) and against Edwardsiella tarda was Ludwigia hyssopifolia (MIC=32 ?g/ml). In those having significant antibacterial activity, Psidium guajava had best extract productivity (5,37%) and second Melaleuca leucadendra (3,37%). This study shows the potential to replace the antibiotics by medicinal plants in preventing and treating fish pathogens in future.

Today the application of information technology for teaching in general and teaching physics in particular has become very popular. Along with the development of information technology, software simulation support for teaching physics also updated more. The software helps learners intuitive, easy to acquire new knowledge while stimulating interest learning, help teachers achieve high efficiency in the process of teaching. Question the teacher will select the software and use them in situations of teaching physics how to achieve the goals in their teaching. In this article present some software applications such as Physics, Interactive Physics, Flash, PowerPoint to design experiments simulate some phenomena physics help students easily absorb more knowledge. These software were also applied to evaluate the academic performance of learners.

Water hyacinth (WH) is an aquatic plant which is considered a serious threat to biodiversity. Using water hyacinth as raw materials for producing mushroom is now necessary matter to get useful agricultural products. ?Effect of the combination ration between  WH and rice straw (RS) on mushroom yield?, was carried out with RCBD, three replications and five treatments such as 100% RS; 25% WH plus 75% RS; 50% WH plus 50% RS; 75% WH plus 25% RS; and 100% WH. The results revealed that The yield of mushroom from WH was the same yield of mushroom from rice straw. However, benefit return of mushroom production from WH is too low. The nutrient was the same in rice straw or WH  mushroom. Heavy metal, such as Pb, Al, Si, Cd was not found in WH mushroom.

Applying electrophoresis technology SDS-PAGE protein process (Japan Department of Agriculture, 1996) to analyze and to 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 showed that all experiment breeds had 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.

Models for intercropping mung beans with cassava obtain yield of 31.9 tons/ha and increase 25.2% compared to cassava monoculture. The intercropping models get a higher return than the ones 14,789,000 VND/ha. In spite of farmers' low input, interest of the models increases 2.88 times as high as monoculture of cassava. Therefore, application of measures for intercropping mung beans with cassava causes 26.29% lower soil loss in comparison with cassava monoculture. It is suggested that applying measures for intercropping mung beans with cassava has a similar condition with the sloping land of southern coastal central zone and central highland.

Water in rivers at theMekongDelta is now polluted seriously.  Sources of polluters come from agricultural activities due to uses of fertilizers and pesticides, human activities, and untreated discharge water form industrial activites. Public?s perception on water river pollution was quite high. Among social issues, education, proverty, and environmental pollution were highly concerned. Most of respondents thought that river water in the study site had a bad quality. It was said that river water in theMekongDelta was facing the pollution and it needed to be protected. There was 62 percent of respondents believed that they were responsibility of protecting the river from the pullution. A high proportion of willingness-to-pay suggested that the probability of success of social program for protecting the river from the pollution was highly expected.

This study was conducted in order to evaluate and select some cocoa cultivars producing huge fruit, great number of seeds, thin fruit cover, and high quality seeds possessing high total lipid content. The study was implemented in cocoa farmer?s plantation in Chau Thanh district, Ben Tre province. Five trees of each clone were investigated, and each tree was collected 6 fruits. Lipid content in cocoa bean was extracted by AOAC protocol (2003), basing on the principle that lipid matter can be diluted in ether, phenol or acetone. Seven cocoa species was evaluated from Jamuary/2005 - January/2006 in accordance with some characteristics, i.e. shape; color of fruit and beans. Results showed that, two cultivars, TD9 and TD7, produced huge fruits with high number of bean which also possessed high total lipid content. Besides, they were determined to be potential cultivars in Chau Thanh district, Ben Tre province.

Evaluation of land suitability and land use selection to meet to the objectives of socio-economic, physical and environment criterions that response to the people and local present situation were very neccessary. This is as a basic for land use planning and also for assessment of the sustainability development for local government. The results from the data of field work and interview, four criterions were identified to assess the qualitative for land use recommendation: i) safe food; ii) increase benefit; iii) social effect and iv) sustainability environment. Based on the results of physical land evaluation and criterions  application, the result showed that in Tam Binh village with 94 land unit were found, in that have 06 land use types and attain the most effective is 02 rice-fish. Towards Hong Dan village have 19 land unit, 5 land use types and 03 land use types such as shrimp-rice/fish, shrimp-rice and rice-fish shows much promise.

With appropriate research methods, this article analyzes the needs and propose solutions basically for the development of cooperation economy in the agricultural production of farming households in Chau Thanh district, Hau Giang Province. In general, 88% of the households are in need of cooperation in the process of agricultural production. This figure for fruit-growing households is 84%. As for rice-growing households, this need is even higher because 92% of them would like to cooperate with others. The reason for cooperation is that the process of rice growing requires many stages that cannot be postponed. In addition, rice growing heavily depends on the weather. There are two short-term and seven long-term solutions to develop cooperation economy in the agricultural sector of Chau Thanh district, Hau Giang province in line with the cooperation need of the farming households.

This paper purposes to design a traffic light system for a crossroads with its signals depend on traffic flow situation acquired from two cameras observing two roads. An algorithm for traffic density estimating and 25 rules of a fuzzy controller are developed to determine the next green signal period. An ATMEL AVR ATMega16-based light driver and an experimental model using plastic balls simulating transports are implemented to verify the control algorithm. Results of 450 experiments indicate which road has higher traffic flow has longer green signal period and reverse. The maximum and minimum periods are correspondently 78±2 and 18±2 seconds in case the traffic flow of one road is 4 times higher than the other one.    

The organic degradation is the activities of microorganisms in carbon and nitrogen cycle. The six best isolates composed of cellulolytic bacteria, amylolytic bacteria and proteolytic bacteria together with mesophile and thermophile were evaluated organic wastes degradation ability in an organic ? waste degrading experimental model (10 ? liter bioreactor). The experiment was a randomized completely design with four replications and the experiment had eight treatments to study organic wastes degradation ability of the isolates in 22 days; Temperature, pH, % lost waste-volume, % reduced waste dry-weight, organic matter, N total, C/N ratio, CO2, CH4 gas and bacterial population were recorded in the different times. The results showed that mesophylic cellulolytic isolate [C1 treatment] reached to most appropriate parameters as temperature, pH, C/N ratio for matured compost, high bacterial population in comparison to control and other treatments. Furthermore, low amounts of CO2 and CH4 gas releasing during the degradation process of these isolates did not affect to environment; Biowaste degradation process reached to maximum at 16-18 days after incubation and this isolate will be chosen to study in later experiment.

The wavelet transform for multiscale edge detection (MED) was used in the field of the inversion problem of geomagnetism to determine the positions and the depths of sources. In this paper, we used the line-weight function (LWF) to treat the observational data to enhance the resolution of the results of MED method. Firstly, the method was applied on the magnetic experimental model to prove the reliability of method and secondly, the method was used to interpret the magnetic profile inMekongdelta area. The results shown that this method can determine the positions and the depths as well as the widths, the thickness and the dip of the sources. The determination of these parameters of sources is the special achievement comparing with other methods.

Three Azospirillum lipoferum strains isolated and identified by Polymerase Chain Reaction (PCR) technique were used to test their ability of synthesis of Indole Acetic acid (IAA) and their effects on the growth of rice root cultivated in the greenhouse. The results showed that all of three strains R7b1, R8b2 and R29b1 could synthetized high amout of IAA than the control in the medium without Tryptophan. Azospirillum lipoferum strain R29b1 could synthesized the highest amount of IAA (19,9àg/ml) after inoculating 4 days. These amount of IAA supported the growth of rice root length and the amount of lateral root grown in the green house. After inoculating 28 days, the rice root length were 2.03 times compared to the control.

The Mekong Delta is considered as the main region of food security, and agricultural and  fisheries?s production ofVietnam. However, its livelihoods of farmers are still limited. Though analyzing in both statistical data of social?economics, from 2000 to 2006, and survey of 334 farm ? households in 2007. Results showed that the region gave more than 50% of rice production and 90% of rice export of the country, and more than 60% of fisheries? production and 80% of fishery? exports. However, farmers faced with some problems of their low levels of education, unskills of labor, and small land. Morever, farmers? saving was very low because of high costs for their familily? living expenditures, for their production?s inputs; their return to the bank? loan with an interest and their neightbor?s relationhsip; as results their average saving arround 6 milions VNĐ with household of 4-5 members per year that were recorded. In order to solve problems above, the implementation of ?Tam Nong? policy by regional approaches and participation of four houses (Government? house, Scientific house,Enterprisehouse, and Farmers) will be strongly recommended..

This study was carried out from March, 2007 to March, 2008 inCanthoUniversity. The study was focused on feeding habit and reproductive biology of Mastacembelus armatus. Fish samples of 30 fishes were collected monthly. The results showed that Mastacembelus armatus is carnivorous fish with insect (40.6%), small trash fish (23.9%), and crustacean (16.4%) were mostly found in fish stomach. The ovary of M. armatus developed through out 6 stages (I-VI). The spawning season was from on May to August, focused on June and July yearly. Gonasdo somatic index (GSI) of female and male zig-zag eel were 3.61 and 0.21, respectively. Absolute spawning fecundity was in range of 11.209 - 45.631 eggs/female.

The aim of this study was to evaluate the time needed to leach salinity in sludge sediment of shrimp ponds in combination with changes of soil nutrients in crop production. Twelve samples of waste sediment were collected to measure the changes of salinity and of nutrient status. These samples were taken from three different shrimp cultivation patterns: intensive, semi- intensive and extensive shrimp cultivation. Results showed that after three months of raining, the waste sediment of intensive shrimp ponds  reached below the critical point level of salinity in soil whereas the rest two shrimp cultivations needed only one or two months. Concerning the concentration of nutrients, available phosphate, available nitrogen, and labile nitrogen decreased after three months of raining. However, these nutrients in the intensive cultivation type still remained rich compared to the semi-intensive and the extensive cultivation types. Based on these results, the sludge sediment in the shrimp cultivation are rich in nutrients for plants. They can be used for agricultural production after leaching away the salinity in soil in a duration of one to three months in rainy season.

The contribution of online peer feedback in EFL writing classes to learners? motivation in learning to write and their writing ability has been empirically researched and reported in bodies of literature. In this paper, we present the results of our study on the imapct of using online peer feedback on learners? motivation in learning to write in English and their writing ability. The study explores the correlation between learners? motivation and their writing ability. Results showed a significant difference in learners? motivation in learning to write and their writing ability between the experimental and control groups. Students in the experimental condition gained more to those in the control condition in motivation and writing ability.

In recent years, brown plant hopper was one of the serious pest and had caused a big lose of rice production in the MekongDelta and South-Eastern region. Some rice varieties, which were selected by Universityof Can Thoand CBDC-BUCAP project were tested by NCVESC[1] in Dry Season 2009 and Wet Season 2009 for evaluating their adaptability to BPH pressure in theMekong Delta and South-Eastern region. The results showed that some varieties such as MTL523, NV1, NV2, HĐ 4 (in Dry Season 2009) and BL29, MTL495, MTL547, MTL560, MTL645, TC1, VT1, BL47 (Wet Season 2009) resisted to BPH at medium level (score from 4.3 to 5.0). Based on the agronomic characteristics, BPH infected capacity, blast resistance and yield in many trial sites in theMekong Delta and South-Eastern region, there are some promising rice varieties such as: MTL500, MTL523, NV1, BL29.

The study was carried out to develop a multiplex RT-PCR protocol for simultaneous detection of WSSV and IHHNV black tiger shrimp Penaeus monodon and to control false negative by detecting shrimp endogenous ?-actin gene. Based on PCR protocols to detect WSSV from OIE (2006), IHHNV from Yang et al., 2006 and RT-PCR protocol to detect b-actin endogenous gene from Oanh (2008), two mPCR protocol were developed including: (1) protocol for stimultaneous detection of WSSV and ?-actin which PCR product of 1447 bp (WSSV) and 216 bp (?-actin) (Tran Nguyen Diem Tu, 2008) and (2) protocol for stimultaneous detection of IHHNV and ?-actin with PCR product of 703 bp (IHHNV) and 216 bp (?-actin) (Duong Thi Kim Loan, 2009). From these results, protocol for stimultaneous detection of WSSV, IHHNV and b-actin were developed and optimized. This mPCR protocols has a practical application by using internal control ?-actin and  reduced cost and save time as two viruses will be detected in a single PCR reaction.

?The effects of N-(phosphonomethyl) glycine and ethrel on growth and sucrose accumulation of sugarcane? was examined on sugarcane DLM24 cultivar at Cu Lao Dung District of Soc Trang Province. The experiment was carried out in randomized complete block design with five treatments and four replications. The ripeners such as N-(phosphonomethyl) glycine 450 ppm, n-(phosphonomethyl) glycine 520 ppm, ethrel 450 ppm and ethrel 500 ppm were sprayed on leaves of sugarcane at the 45th day before harvesting. Control is the non-treated sugarcane with chemical. The results showed that N-(phosphonomethyl) glycine and ethrel increased sucrose accumulation from 1.7% to 3.1% compared with control. N-(phosphonomethyl) glycine 520 ppm showed the best effect. The commercial cane sugar of the treated plant reached to 13.3% while that of the control was 10.2%. The ripener treatment technique can be applied to increase sugarcane production.

Cohesion in general, Conjunction in specific plays a crucial role to support for coherence of texture. Thus, Conjunction is also an important element of Creative and Comprehensive Texture Process. Considering sentence as an object (elements connect two or more sentences are called conjunction words), we observe variety kinds of cohesion relations, thanks to their meanings in the interactive context. Infact, conjunction words just are formal forms which are used to express meaning exiting potentially in the language. In this short article, we want to mention more about Elaboration relation in Vietnamese ? one of the basic relations of conjunction, which have some sub-kinds being different from previous view-point.

Research results show that groundwater use increased considerably in Tra Vinh in the years. The quantity of groundwater was exploited for domestic activities to increase in every year. Research results show that groundwater use in 2004 was about              80,000 m3/month and water consumption continually increase the average per month is 180,000 m3 per month and more than 200,000 m3 per month in 2006 and 2008, respectively. Growth and exploitation of groundwater use increased 10 times in about 2 years from 2004 to 2006. Total volume of the water in 2004 was one million m3 per year, while the amount of groundwater in 2008 is 2.5 illion over m3 per year. Groundwater qualities in Tra Vinh lower than groundwater standard of Viet Nam (TCVN 5942-1995). However, most groundwater quality is contaminated with Coli-form (density of 4-2400 MPN/100 ml). The challenges for farmers are dropped of groundwater quality. Solutions to save groundwater are changing kind of plants, but there are many difficulties to find kind of plants using less water.

Micropropagation of elephant?s ear (Caladium bicolor) was carried out to establish a protocol for micropropagation of this plant. Experiments were conducted (1) surface sterilization, (2) shoot proliferation, (3) rooting and acclimatization. Results of experiments showed that tubers were sterilized twice with Clorox 20% for 15 minutes, then rinsed with sterilized distilled water and added HgCl2 0,050/00 for 30 minutes. Results obtained 91,67% completely clean explants. Shoots were multiplied on MS medium supplemented with 0,5 ? 2,0 mg/l BA or 0,1 mg/l NAA (4,3 ? 6,0 shoots/explant). Root ratio obtain highly (13.7 roots/shoot) on the medium supplemented 0,5 mg/l NAA. On MS medium added 0,5 ? 1,0 mg/l BA or 0,1 mg/l NAA alone, plantlets obtained high number of leaves (12 - 16 leaves/explant). A substrate for acclimatization consisted of degraded rice straw + rice hull ash, degraded rice straw + coconut powder and fiber or degraded rice straw + rice hull ash + coconut powder and fiber with equal mixed ratio in nylon covered condition to maintain high relative humidity obtained highly survival ratio.

The main objective of this study is to measure determinants of Nokia purchase intention of consumers in Can Tho city. Data used in the study were collected from a questionnaires survey of 150 mobile phone users. Using Cronbach Alpha and Exploratory Factor Analysis (EFA) approaches, 20 initial oberserved variables measuring purchase intention of customers are grouped into 5 factors that are included in the regression model as independent variables. Empirical evidence derived from the regression model revealed that quality of service, perceived price, perceived quality of products and product features are determinants of Nokia purchase intention of customers in Can Tho city.   

The paper presents a sliding mode controller using Takagi-Sugeno fuzzy model. Robot with one DOF (Degree of freedom) is used to examine the control algorithm. The method can control the position of the robot arm tracking on desired set-point signal even throught disturbance is added. Almost the real plants are often affected by many noisy resources from the working environment. A normal feedback controller is difficult to maintain the stability of the system. In contrast, sliding mode controller can effectively direct both linear and nonlinear plants with adding noise. However the controller make chattering phenomenon around sliding surface. Therefore a proposed solution will combine the sliding mode controller with Takagi-Sugeno fuzzy model for decreasing the above problem. And the fuzzy model is used to replace for sign function of sliding control law. The practical results were tested with simulink software of Matlab. Basing on the results, sliding mode controller using fuzzy model indefectibly controls the nonlinear system. 

This study was carried out in order to evaluate tolerant characteristics to some stress conditions; protection capacity (Yoshida, 2009) against anthracnose (Colletotrichum orbiculare); and to examine Pathogenesis-related genes expression in cucumber plants. The three strains was evaluated tolerance capacity at different temeperature regimes (23, 30, 35 and 40oC); in media supplemented with 0.5 and 1 M NaCl; and at different pH conditions (pH 4, 7 and 8). Bio-control activities was evaluated by spot challenge of C. obiculare on true leaf surface of seedlings pretreated with Actinomyces strains. Results showed that A12 and A19 strain could adapt well to high temperature condition          (35-40oC). A12 and A16 strain can adapt well to supplemention of NaCl 1M. All three strains can response well to both pH levels (4 and 8). Among the three candidates, A12 strain exerted the greatest protection effect which was reflected by significant declining         (p< 0.01) of both lesion area and lesion number. A12 strain at OD660=2 was determined to be the best concentration to be applied. Result of PR gene expression reflected that, PAL gene was expressed clearer in true leaves pretreated with A12 strain in comparison to that expressed in the other strains and control.

Zoobenthos structure was studied at Cai May canal, Phu Tan district, An Giang province in June and November 2008. Water quality was assessed by BMWPViet Nam. The results showed that water quality at all sites were organic polluted from ? ? Mesosaprobe to Polysaprobe. Water quality in June 2008 (the beginning rainy season) was better than in November 2008 (the end rainy season).

Water in rivers at the Mekong Delta is now polluted seriously. Sources of polluters come from agricultural activities due to uses of fertilizers and pesticides, human activities, and untreated discharge water form industrial activites. The paper showed that majority of respondents were willing to pay for the program protecting river not be polluted. Applying the contingent valuation method, the mean willingness to pay estimated by Probit model was 29,345 VND/household/year and the total economic losses were estimated at 1,454 billion VND/year. Probit and OLS models? results showed that variables: option price, household income, respondent?s age, sex, educational status, resettlement, number of children, uncertainty on river water supply and demand, and concern on the pollution status statistically significantly affected to the willingness to pay to avoid the pollution happen. 

The experiment on induced breeding of Pangasius conchophilus with three types of hormones being  HCG, Ovaprim and LRHa were carried out at Aquaculture Seed Center of Dong Thap province from July, 2007 to July, 2008. The  results  showed that, HCG or Ovaprim stimulated ovulation at the dose of 5.000 -6.000UI and 0.4-0.6ml per kg of female, respectively. The spawning rates were 88,89-100%, the relative fecundity ranged from 44.706 to 60.716 eggs per kg of female. Fertilization rates were 77.0 ? 84.45% and hatching rates were 74 ? 83.90%. Hormone LRHa at the doses of 150-250mg combination with Motilium at the doses of 20mg per kg  could not stimulate ovulation.

This study was carried out to determine rice yields on different draining-water methods in the fresh rice straw and stubble incorporated acid sulphate soil (Sulfic Humaquepts Tien Giang). Factorial in Complete Block Design was used with 4 replications, there were 2 factors with factor 1 in 3 draining-water methods ((i) flooding, (ii) draining-water method at 15 days after sowing in 5 days and (iii) draining-water method at 30 days after sowing in 5 days) and  factor 2 in 4 weights of fresh rice straw and stubble ((i) 0.0; (ii) 1.25; (iii) 2.5 and (iv) 5.0  g.pot-1 of 4 kg dry soils). Results indicated that the draining-water methods at 15 or 30 days after sowing helped to increasing Jasmine85 rice growths of plant height, number of tillers per pot, number of panicles per pot, number of full grains per panicle and rice yields (28.96 and 29.16 g.pot-1) versus flooded rice soil (23.81 g.pot-1), there is about 22.5% higher rice yield. The fresh rice straw and stubble incorporated soils (1.25, 2.5 and 5.0 g.pot-1) were decreased plant height, number of tillers, number of panicles, number of full grains and rice yields (from 15, 25 and 34% lower rice yields); the draining-water methods of rice soils were quickly decreased in total orgarnic acids (below 1000 mmolc/m3) and H2S (below 0.07 ppm), but increased pH values and NH4+ concentration in soil solutions helping to well rice growths and yields.

Isolation of the chemical components from the root of Vietnamese mangrove plant Avicennia marina (Verbenaceae) cultivated in the coast of Bac Lieuprovince found the mixture of lupeol (C30H50O) and stigmasterol (C29H48O) from petroleum ether extracts, kaempferol (C15H10O6) and esculetin (C9H6O4) from ethyl acetate extracts. Structures of these compounds have been elucidated by modern spectroscopic methods: MS, 1H-NMR, 13C?NMR, HSQC, COSY and HMBC.

This study was conducted to determine effect of nitrogen levels applied at post-harvest stage on off-season flowering and yield of ?Xuong Com Vang? longan in Chau Thanh district, Dong Thap province. 4-5 year-old longan trees, propagated by grafting ?Xuong Com Vang? scion on ?Da Bo? rootstock, were investigated from 8/2007 to 6/2008. Treatments were four levels of nitrogen (35, 70, 140 and 280 g N per tree) applied at post-harvest stage to induce shoot flush. The experiment was arranged in complete randomized design with 6 replications, each replication equal to one tree. After harvesting, besides nitrogen doses mentioned above, each longan tree was supplied 1 kg of bio-humic fertilizer, 184 g P2O5 and 70 g K2O. Flowering induction was conducted at the third flush by collar drench application of 24 g chlorate potassium per canopy meter, in association with succeeded main branch cincturing (3-5 mm in length). Results showed that applying nitrogen fertilizer post harvesting at the dose of 70 g per tree, as control treatment, increased length as well as diameter of shoot, and reduced N content of leaf at flowering stage which relatively increased C/N rate. Furthermore, that nitrogen dose also help achieved high flowering rate, which brought about high yield as a result of high rate of both flourescene/tree and fruit/flourescene.