Published: 2018-10-26

Identification and antibiogram of Haemophilus parasuis circulating in pig farms in some southern provinces of Vietnam

Quynh T. X. Luong, Duong T. T. Do, Phuong T. Hoang, & Phat X. Dinh
Electronic version: 26 Oct 2018 | DOI: 10.52997/jad.9.05.2018
Abstract | PDF (373.6K)

Abstract

Haemophilus parasuis (HPS) causes polyserositis in swine and is characterized by pneumonia, pleurisy, peritonitis, cardiomyopathy, arthritis and meningitis. To assess the current status of antibiotic resistance of HPS in industrial pig farms, 245 specimens were collected to isolate HPS on chocolate (PVX) supplemented with NAD. A total of 51/245 specimens had suspected HPS colonies (20.8%) and those colonies were subsequently identified by traditional methods (gram staining and biochemical tests) in combination with PCR using primers specific to a fragment of 275 bp of peptidase M1 gene. Twenty-one colonies (8.6%) were identified as HPS and then were tested for resistance to the nine antibiotics which are popularly used in swine farms. The results of the antibiogram showed that all of these HPS were multiresistant bacteria. The percentage of isolates resistant to 7 types, 6 types and 5 types of antibiotics was 33.33%, 28.6% and 23.8% respectively. Resistance rate was highest forty losin (91%), followed by tilmicosin (81%), tulathromycin (62%), enrofloxacin (62%), lincomycin/spectinomycin (57%), amoxicillin (52%), florfenicol (48%); ceftiofur (10%) and doxycycline (5%). These findings pose a big concernabout the antibiotic resistance of HPS in pigs and that measures should be taken soon to improve this situation. 

Determination of Riemerella anatipestifer and Escherichia coli suspected to cause a syndrome including shaking head and trembling, greenish diarrhea on duck farms in Long An

Hien T. Le, Quan N. Kha, Khuong M. Chu, Cuong V. Nguyen, Ngoc H. Le, & Hoa T. K. Ho
Electronic version: 26 Oct 2018 | DOI: 10.52997/jad.7.05.2018
Abstract | PDF (260.1K)

Abstract

In Long An province and other places, ducks at 3-8 weeks of age often experience a syndrome including greenish diarrhea, eye and nose discharge, shaking head and trembling which is considered to be related to Riemerella anatipestifer and Escherichia coli. There is not any research to prove this hypothesis. For that reason, this study was as the first step to explore the causes of this syndrome. In to-tal, 70 swab samples from disease and nondisease ducks and 27 pool water from 27 duck farms were collected to identify R. anatipestifer and E. coliusing PCR. There were 2 PCR (16SrDNA-PCR and gyrB-PCR) used to detect R. anatipestifer while one PCR for gene phoA was used to detect E. coli The result showed that R. anatipes-tifer was found on both disease and non-disease ducks. However, the 2 PCRs to detect R. anatipestifer did not agree well. The fact that these bacteria were found on 22% farms (disease and non-diseaseones) means it is complicated to confirm them in causing the men-tioned disease. In addition,E. coliwas also found in both types of duck and from all pool water. These isolates were kept for further studies to identify their virulence. The result reveals that there may be the cooperation between many factors in causing this disease.

Separation of active constituents in some medicinal plants by thin layer chromatography

Tien T. Tran, Nhan T. T. Nguyen, Tien T. Ha, & Lan T. Q. Tran
Electronic version: 26 Oct 2018 | DOI: 10.52997/jad.8.05.2018
Abstract | PDF (260.1K)

Abstract

Separation and identification of the active pharmacological compounds from some medicinal plants (Citrus aurantifolia, Rhodomyrtus tomentosa, Camellia sinensis) by Thin Layer Chromatography (TLC) showed the yields of crude extracts ob-tained from Citrus aurantifolia, Rhodomyrtus tomentosa and Camellia sinensis leaves at 1.5%, 5.62% and 10.4% respectively. Toluene: ethyl acetate (93:7) (v:v) solvent was suitable for the separation of active compounds in crude extract of Citrus auran-tifolia, Rhodomyrtus tomentosa leaves while chloroform: ethy-lacetate: formic acid (5:4:1) (v:v:v) solvent was suitable for the extraction of active compounds in crude extract from Camelliasinensis leaves. Furthermore, the results showed that the num-ber of compounds in extract from Citrus aurantifolia were like lyaffected by the vacuum evaporator effects. The TLC fingerprints of all three medicinal plants had the same visual ability when the fingerprint detected by UV (λ= 254 nm) and the reagent containing 0.1 g vanillin in 28 mL of methanol: 1 mL of sulfuric acid. In brief, the three active compounds including citral (Cit-rus aurantifolia), rhdomyrtone (Rhodomyrtus tomentosa) and catechin hydrate (Camellia sinensis) contained in the extract of 3 medicinal herbs had the limited detection (LOD) at 195 ng/spot, 321.5 ng/spot and 625 ng/spot, respectively.

Study on in vitro propagation of Giao co lam (Gynostemma pentaphyllium Thunb.)

Trinh L. D. Ho, Vi T. T. Nguyen, & Kim T. A. Phan
Electronic version: 26 Oct 2018 | DOI: 10.52997/jad.11.05.2018
Abstract | PDF (260.1K)

Abstract

Giao co lam (Gynostemma pentaphyllium Thunb.) is a traditional medicine plant and endangered species in Vietnam. The research was carried out to establish the plant propagation for the purpose of conserving and exploting this endangered medicinal herbs. The young leaf and nodes of Giao co lam in vitro were used as explants in the study to evaluate the factors influencing the multiplication. Young leaf explants were excised and cultured in MS medium with TDZ from 0.1 to 1 mg/L. After 10 weeks of culture, new shoots came out from their explants and the MS medium containing TDZ 0,7 mg/L gave the highest shoots (12.89 shoots/explant) with the average percentage of 74.67%. When nodal explants were cultured on MS supplemented with BA at a concentration of 0.3 to 1.5 mg/L and IBA 0.5 mg/L. After 6 weeks of culture, explants on MS medium supplemented with BA 1 mg/L and IBA 0,5 mg/L gave the highest shoots (7.39 shoots/explant) and their average percentage was 83.33%. In comparison to the nodal explant medium in combination with BA (0.5 to 3 mg/L) and NAA 0.2 mg/L for 4 weeks of culture, the best rapid shoot multiplication score was 3.67 times with MS + BA 1.5 mg/L + NAA 0.2 mg/L as compared to MS + BA 1.0 mg/L + IBA 0.5 mg/L. Suitable medium for rooting was MS + 0.5 mg/L IBA with root shoots at 97.33%, average roots at 5.29 roots/shoot after 4 weeks. On organic substrat, 70% coconut fiber and 30% composted cow manure gave the highest survival rate of 91.33%. The plants grew and developed well during the nursery stage. 

Determination of malondialdehyde and glutathione levels in the liver of mice orally administered with a mixture of the aqueous extracts of Ganoderma lucidum (Curtis) P. Karst, Mint (Mentha avensis L.) and stevia (Stevia rebaudiana Bertoni)

Minh T. L. Tran, & Ly T. H. Nguyen
Electronic version: 26 Oct 2018 | DOI: 10.52997/jad.10.05.2018
Abstract | PDF (260.1K)

Abstract

Oxidative stress has been studied by scientists because it is a factor increasing diseases, such as cancer, diabete... through the production of harmful free radicals to the body. Ganoderma lucidum (Curtis) P. Karst is always considered an important drug in the prevention and treatment of diseases by the action of polysaccharide and triterpenoid. In addition, Stevia rebaudiana Bertoni has recently been shown to have antioxidant and anti-inflammatory properties. Mint (Mentha avensis L.) is a common medicinal herb. The mixture consisting of the aqueous extract of Ganoderma lucidum (Curtis) P. Karst, mint and stevia powder had a high antioxidant activity, in free radical scavenging method (DPPH), reaching 85.7% at concentration 1000 µg/mL and valuable IC50 was 559.7 µg/mL. For in vivo study on the model of cyclophosphamide-induced liver damage in white mice, the concentrations of malondialdehyde and glutathione in liver showed that the mixture had antioxidant activity in the direction of hepatoprotective effect.

A study on processing conditions of fermented acerola juice

Thanh T. Le, & Tuyen C. Kha
Electronic version: 26 Oct 2018 | DOI: 10.52997/jad.15.05.2018
Abstract | PDF (260.1K)

Abstract

This study investigated some key processing steps of fermented acerola juice, including variety, maturity, enzyme treatment, sugar concentration and fermentation and pasteurization conditions. One or two-factor experiments were randomly designed to determine the most suitable processing variables based on the investigated parameters, including the content of vitamin C, sensory quality and  physicochemical properties of the resultant juice. The results showed that the Brazil variety (Malpiphia emarginata D.C) had highest vitamin C content (1567.9 mg/100 g), followed by sour variety (Malpiphia glabra L.) (882.9 mg/100 g) and sweet variety (Malpiphia punicifolia L.) (630.4 mg/100 g). However, according to sensory evaluation results, the sour acerola juice after fermentation had the highest overall score, indicating to be the most suitable for processing. The fermented juice of sour acerola variety at 100% maturity had the highest sensory score and vitamin C content compared to other levels of maturity. In order to enhance the clarity of acelora juice, the addition of 0.15% pectinase enzyme (Pectinex ultra SPL, Novozymes) was the most effective compared to 0.05 and 0.1% (w/w) enzyme concentrations. The fermentation at 15oC in 48 hours with 22% sugar concentration and 0.1% commercial yeast (Saf-instant, France) obtained the highest quality fermented juice. The fermented product was pasteurized at 80oC for 10 minutes to stop fermentation process as well as to retain the color and taste of the fermented juice. The good quality of the fermented acerola juice, in terms of physicochemical, sensory and microbiological properties could be maintained for at least 6 months.

Developing a set of competency criteria for college – level workforce in the business sector

Tri M. Tran, Vinh T. Hoang, & Huy D. Dang
Electronic version: 26 Oct 2018 | DOI: 10.52997/jad.1.05.2018
Abstract | PDF (260.1K)

Abstract

In the context of rising unemployment of college-level workforce while the need for business exists, the development of a set of competency criteria is needed to help students have a better preparation in order to meet the needs of employers in the future. This research aimed to meet the requirements. The research used data from two surveys, including 30 employers and 300 students from 5 universities. The analysis methods were the descriptive statistics and the T-test, conducted on the Stata 12 software. As a result, the study selected 15 most important competencies in 30 initial aggregated ones. Analyzing the set of competency criteria, the results showed that there was a significant difference in perceptions about the importance of criteria between students and employers. While employers considered the skill and attitude criteria to be more important, the students punctuated the criteria of knowledge. In addition, the findings showed that students had not yet met what the business needed in all 15 criteria at the current time.

Analysis of factors affecting consumers’ intention to purchase organic vegetables in Ho Chi Minh City

Chung T. Q. Le
Electronic version: 26 Oct 2018 | DOI: 10.52997/jad.2.05.2018
Abstract | PDF (260.1K)

Abstract

Food safety is a matter of concern to the society, in which the organic food market is developing very strongly in Ho Chi Minh City in particular and the Vietnam market in general. The study was conducted by interviewing 372 consumers living in the city to analyse the present situation of organic vegetables consumption in the investigated area, to analyse factors affecting the intention to consume organic vegetables and propose measures to develop organic vegetable smarket in Ho Chi Minh City. Data processing methods included Cronbach’s Alpha, EFA, CFA, and SEM. Research results showed that there were four main factors influencing the intention to consume organic vegetables. The most important factor was subjective noms, followed by consumers’ beliefs in organic vegetables, the attitude of consumers towards organic vegetables and consumer’s perception of the price of organic vegetables.

Adjustment of the formula of local surface water quality assessment

Hung V. Bui, & Nhi M. U. Tran
Electronic version: 26 Oct 2018 | DOI: 10.52997/jad.13.05.2018
Abstract | PDF (260.1K)

Abstract

Water quality index (WQI) is widely applied for the assessment of water quality (WQ) according to decision No. 879/QD-TCMT of the Ministry of Natural Resource and Environment in most of the provinces. During the application process, the WQI has revealed many problems, such as inacculate assessment of water quality status, not addressing locally economic, social and environmental conditions, and easy misleading when using abnormally increaed values,... To resolve the above problems, the paper presents the steps to adjust the water quality index based on the current water quality components of the old WQI formula, the fuzzy comprehensive evaluation theory with the Entropy rate method. With the surface water quality data series and the status of the water use in the main river canal system in Vinh Long City from 2012 to 2017, the computation steps of coefficients and rates of the assessing water quality components are identified; through the new assessment water quality formula is adjusted and tested.

Evaluation of effectiveness in public - private partnerships (PPP) for solid waste management case study of Ho Chi Minh City

Huong T. M. Hoang, Hue K. Nguyen, Phu B. Hoang, & Chau T. Q. Le
Electronic version: 26 Oct 2018 | DOI: 10.52997/jad.12.05.2018
Abstract | PDF (260.1K)

Abstract

The research was conducted to evaluate the effectiveness of public & private partnership (PPP) in solid waste management of Ho Chi Minh City, where many pilot projects have been developed as illus-trations for Vietnam in the past years. The research used OECD criteria for policy evaluation and had discussions with specialists to evaluate the effectiveness of public & private partnership (PPP) in solid waste management of Ho Chi Minh City. The results indicated that the pilot projects achieved significant successes in meeting the management objectives such as reducing burdens on public invest-ment for urban environmental services, minimizing pollutions caused by municipal solid waste, and applying advanced technologies to the final treatment and/or disposal. The research, however, also pointed out the disadvantages of PPP during development, which are mostly relevant to supporting regulations or implementation capacity. From those outputs and lessons learnt from other cases in the world, some recommendations have been proposed for improving the effectiveness and spreading the implementation of PPP in other places.

Effects of seeding density and nitrogen fertilizer level on growth and yield of MT10 rice in Ninh Thuan

Tieu V. Phan, Tinh T. Le, Phuoc V. Pham, Kien C. Phan, Thu M. Vo, Nhan T. Nai, Ty Do, Ty Q. Pham, & Lieu T. Nguyen
Electronic version: 26 Oct 2018 | DOI: 10.52997/jad.6.05.2018
Abstract | PDF (288K)

Abstract

The experiment was conducted to determine seeding density and nitrogen fertilizer doses for the MT10 rice variety grown in the winter-spring crop 2015/2016 and the Summer-Autumn crop 2016 in Ninh Thuan. Both experiments were established using a randomized complete block design with three replications. The seeding density experiment was performed in winter-spring season 2015/2016, including density levels of 120, 160, 200 and 250 kg/ha. The nitrogen fertilizer dosage experiment was organized in summer 2016, including 4 levels of 100, 120, 140 and 160 kg N/ha. Other non-experimental elements were identical. The results showed that the highest yield and economic efficiency were for the treatments of 200 kg seed/ha with a nitrogen fertilizer dose of 140 kg N/ha. 

Effects of types and rates of mixing materials, concentration of effective microorganisms on anaerobically composting process of coffee husks

Duong T. Nguyen, & Tam T. M. Pham
Electronic version: 26 Oct 2018 | DOI: 10.52997/jad.5.05.2018
Abstract | PDF (260.1K)

Abstract

The use of coffee husks for aerobic composting of organic com-pounds with Trichoderma preparations is currently common in the Central Highlands but the incubation time is prolonged. Therefore, the objective of this research was to find out the type, rate of mixing materials and the optimal concentration of EM preparation to anaerrobic composting process of coffee husks to shorten the brewing time is necessary. This research was com-posed of two experiments, in which two factors were arranged with the full block random type with three replications. The first experiment consisting of factor A was materials mixed with coffee husks type (A1: manure (cow dung); A2: fresh straw; A3: veg-etable waste) and factor B was rate of mixing materials (B1: 0% (control); B2: 20%; B3: 30%). The second experiment consisting of factor A was mixing materials type with rate of 30% (A1: no used mixing materials (control); A2: fresh straw; A3: cow dung) and factor B was concentration of EM preparation (B1: 0 mL/l(control: water); B2: 10 mL/L; B3: 20 mL/L). The results showed that 70% coffee husks mixed with 30% cow dung and EM mixture(20 mL/L) gave the highest total protein content of 1.82% and a C/N rate of 22.68 with a shortened brewwing time of sixty days only.

Determination of the amount of irrigation water for cucumber (Cucumis sativus L.) grown on four types of substrate

Nguyen H. Pham, Hung T. Huynh, & Dung T. Nguyen
Electronic version: 26 Oct 2018 | DOI: 10.52997/jad.3.05.2018
Abstract | PDF (260.1K)

Abstract

There are many types of substrate used in soilless cultivation, but each substract has differences in water holding capacity and aeration. Therefore, it is very important to determine the amount of water applied to cucumber grown in various substrates based on the estimated cucumber evapotranspiration requirements (ETc) that can enhance cucumber growth and development, improve yields but reduce costs. The experiment was carried out in the experiment site of Nong Lam University Ho Chi Minh City from June to August 2016 with four irrigation levels and four substrates that were arranged in a split-plot design with three replications. Four irrigation levels (60, 80, 100 and 120% of ETc) were allocated to main plots, and four substrates including 100% coconut coir, 50% coconut coir + 50% peanut shells, 50% coconut coir + 50% sand, and 50% sawdust + 50% sand were allocated to subplots. Growth attributes and yield components of cucumber were determined. The results showed that cucumber grown on the substrate 50% coconut coir + 50% sand and irrigated by 120% ETc (corresponding 226 mL/plant/day at 3 weeks after planting - WAP, 280 mL/plant/day at 3 - 5 WAP and 236 mL/plant/day at late 5 WAP) performed the highest absolute yield and commercial yield (7.50 kg/m2 and 7.48 kg/m2, respectively), and had the highest profit (71,738,746 VND 1,000/m2, and the profit ratio was 1.77).

Effects of different substrates on growth and yield of Limnophila rugosa (Roth) Merr. under organic-oriented farming

Duong T. T. Pham, Thinh V. Tran, & Hung T. Huynh
Electronic version: 26 Oct 2018 | DOI: 10.52997/jad.4.05.2018
Abstract | PDF (260.1K)

Abstract

Using agricultural wastes to produce organic substrates for organic vegetable cultivation is one of the most eco-friendly practices to reduce environmental pollution caused by these wastes. The objective of this study was to determine the best substrate formulation for growth and yield of Limnophila rugosa under organic-oriented farming. A single factor experiment was laid out in a completely randomized design with seven substrate formulations and three replications. Seven types of substrates were designated based on the composed materials of coconut coir dust, vermicompost, rice husk ash, rice husk, peanut shells. The results showed that the mixed substrates of 10% vermicompost + 60% coconut coir dust + 30% peanut shells led to optimum crop performance and highest yield. Particularly at the third harvesting time, Limnophila rugosa performed the highest number of branches (24.3 branches/plant), branch length (14.9 cm/branch), number of pairs of leaves (5.7 pairs of leaves/branch), leaf chlorophyll content (40.3 SPAD value), plant fresh weight (70.6 g/plant), total theoretical yield (7,133.6 kg/1,000 m2), total absolute yield (5,487.3 kg/1,000 m2) and total commercial yield (4,891.8 kg/1,000 m2).