Published: 2019-11-30

Applying AHP method and GIS to evaluate land suitability for paddy rice crop in Quang Xuong district, Thanh Hoa province

Nguyen Huu Hao, Pham Van Van, Khuong Manh Ha
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The major purpose of this research is to seek out appropriate cultivated areas for paddy rice crop production in Quang Xuong District. Therefore, the assessment of land suitability for this crop is essential for land-users and land managers to understand the capacity and restrictions of the existing land conditions for making suitable policies and plans of land use in the fiture. In this research, an Analytical Hierarchy Process (AHP) and GIS were applied to assess land suitability for rice crop. The results find out that 24.82%, 52.33%, 18.40%, and 4.45% of the examined areas were clasified as moderate, marginal, current, and permanent unsuitability levels, respectively for rice production. It was identified that the most important constraint factors in the growth of paddy rice were found to be the topography, organic matter, soil texture, soil depth and irrigation condition. The study also indicates that the spatial information resulted could be used to assist land use based directly on its potential to minimize environmental problems, and increases individual farmers’ incomes through proper use.

Characterization of mouse bone marrow-derived macrophages differentiated in L929 cell conditioned medium and colony stimulating factor-1 in Listeria monocytogenes in-fection

Tran Thanh Thao
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Mouse bone marrow-derived macrophages (BMDM) have been identified as an important host cell model for studying mammalian macrophage functions during pathogen infection. Whereas colony stimulating factor (CSF)-1 is required for BMDM differentiation, the commercial CSF-1, however, is expensive. Therefore, L929 cell-conditioned medium (LCM) has been reported to be used as a source of CSF-1 in many recent studies. However, whether BMDM differentiated by commercial CSF-1 and LCM had any functional differences in bacterial infection, particularly Listeria monocytogenes (LM) infection, has remained unexplored. This study aimed to examine the morphology of macrophages differentiated from CSF-1 and LCM as well as the phagocytic function of these macrophages in LM infection. Mouse bone marrow cells were differentiated in CSF-1 or LCM through 6 days before infected by LM. Phagocytotic roles of BMDM were evaluated throug the capability of macrophages to take up the bacteria, as shown by infection assay and immunofluorescence microscope. The results showed that macrophages grown in CSF-1 and LCM were similar in morphology and phagocytic functions during LM infection. Macrophages from LCM-supplemented media were homogenous and obtained CD11b and F4/80 surface markers. Immunofluorescence images demonstrated that bone marrow-derived macrophages were able to successfully take up LM at 0.5 h but unable to control intracellular bacterial replication by 4 h post infection.

Selection of carrier materials for formulation of the antagonistic Bacillus spp. against rice bacterial leaf blight

Dang Hoai An, Nguyen Dac Khoa, Le Nguyen Xuan Thanh
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Bacillus pumilus ST-115, B. safensis AG-131, B. stratosphericus AG-62 and B. subtilis TG-71 showed strong antagonistic effects against Xanthomonas oryzae pv. oryzae causing rice bacterial leaf blight. This research aims at evaluating the effects of carrier materials on cell densities, the antagonistic effects and disease-reducing effects of these four bacterial strains and selecting the suitable carrier material(s) for each of them. Five carrier materials, i.e., talc powder, rice bran, rice husk powder, rice grain powder and rice kernel powder, were used to store the Bacillus spp. in a six-month period at room temperature. Results show that after six-month storing, formulations of Bacillus spp. using talc powder, rice bran and rice husk powder could remain the cell densities at over 106 CFU/g formulation, the antagonistic effects on agar plates and the disease-reducing effects under greenhouse conditions. Rice bran was the suitable carrier material for B. safensis AG-131, rice husk powder for B. pumilus ST-115 and talc powder for both B. stratosphericus AG-62 and B. subtilis TG-71.

Pathogen identification of sweet potato wilt in Bình Tân, Vĩnh Long

Nguyen Hoang Minh Sang, Nguyen Dac Khoa, Chau Hoang Trung Tin
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This study aims at identifying the pathogen causing sweet potato wilt in Binh Tan district, Vinh Long province of Vietnam using morphological characterization, Koch’s postulates and sequencing the ITS region amplified by primer set ITS1/ITS4. A total of seven fungal isolates were obtained from 14 infected stem samples collected from Binh Tan district. Based on morphological characterization, two isolates CD3 and CD5 were classified into the Fusarium genus, one of the major plant pathogen genera causing wilt diseases. CD5 exhibited typical wilt symptoms using Koch’s postulates and was identified as Fusarium solani based on its ITS sequence. This result serves as a basis for further studies on disease management.

Identification of shallot pathogens in Vĩnh Châu town of Sóc Trăng province

Bui Thanh Thu, Nguyen Dac Khoa, Tran Quoc Tuan
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Shallot (Allium ascalonicum) is an important crop of Vinh Chau town, Soc Trang province of Vietnam. This study aims at identifying the contemporary pathogens in shallot fields in this region. The identification was done using the Koch’s postulates, morphological observation and molecular techniques. A collection of 124 infected shallot samples was obtained from three cropping seasons during 2015-2016 at three major shallot producing areas of Vinh Chau town. From these samples, a total of 49 bacterial and 118 fungal isolates were obtained. Using the Koch’s postulates, 160 isolates were confirmed to be shallot pathogens. Based on morphological observation and molecular techniques, i.e., PCR using specific primers and sequencing of the 16S rRNA genes, the pathogens were identified as Erwinia carotovora (soft rot), Pseudomonas aeruginosa (bulb rot), Aspergillus niger (black mold), Colletotrichum gloeosporioides (anthracnose) and Fusarium oxysporum (basal rot). Among these, E. carotovora and F. oxysporum appeared to be the predominant pathogens causing bulb rot in the shallot fields of Vinh Chau town.

Optimization of Gluten - Free Bread Formulation from bread improver and fermen-tation time

Le Thi Kim Loan, Nguyen Minh Thuy
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The effects of formulation of gluten-free bread based on non-gluten flours (about 100 g) by using the concentrations of hydroxyl propyl methyl cellulose (HPMC), arranging from 1 to 1.5 g, blending with yeast from 2.5 to 3.5 g, water from 95 to 105 g, maltodextrin from 5 to 15 g and fermentation time from 20 to 40 min on specific volume and sensory value were determined. The Box–Behnken factorial design was used in these experiments with response surface methodology. The final optimum formulation of gluten-free bread contained 1.31 g HPMC, 2.96 g yeast, 100.5 g water, 10.04 g maltodextrin, and 30 min of fermentation. In sensory evaluation test and specific volume of the gluten-free rice bread from this optimization of formulation had maximum specific volume (2.4 cm3/g) and the highest score of sensory evaluation (7.4). 

Factors affecting technology transfer in the Mekong Delta

Le Thanh Phong, Le Viet Dung, Doan Van Hong Thien, Tran Trung Tinh, Nguyen Vo Chau Ngan
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ABSTRACTAccording to experts and managers in science and technology (S&T) sector, technology transfer (TT) activities in Vietnam have not achieved the desired results that were reflected by the amount of limited research results applying in production, number of TT contracts were few, and not many businesses considered investing in research and TT activities. This study is aimed to evaluate the current situation of technology transfer (TT) and to determine the factors that affect the TT activities in 13 provinces and cities in the Mekong Delta (MD). The survey involved 80 respondents of organizations relating to TT activities, such as research institutes, universities, and enterprises. The exploratory factor analysis (EFA) was used to analyze 12 observed variables relating to the TT. The results showed that the TT activities were evaluated at average level due to some disadvantages on TT organization, methods, plans, and diversification of TT activities; professional qualifications of labor forces involved; ask-give mechanism in research and TT; limited awareness of enterprises in TT; and complicated financial payment procedures. The results of factor analysis showed that there were three factors: State governance, Commercialization, and Satisfaction explored, in which the State governance factor had the strongest effect on the TT activities. To improve the current TT activities in the MD some solutions were proposed.Keywords: factor analysis, Mekong Delta, technology transfer

Students’ perceptions of a blended learning environment for English training at a university in Vietnam

Phuong Hoang Yen, Huynh Minh Hien, Huynh Chi Minh Huyen
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Blended learning has become an attractive tendency in education worldwide since the internet develops quickly and attracts a vast number of users. In English language teaching and learning, blended learning offers a lot of promising potential in helping learners to acquire and improve their language competence. The current study was conducted at a university in Vietnam to explore students’ overall impressions of blended learning as well as its benefits and challenges. All 165 participants in the current study have experienced learning English in a blended learning environment in two consequential semesters. The findings reveal that more than half of participants had good impressions about the environment and perceived various benefits as well as challenges of it. However, the study implies that to make blended learning more effective in Vietnam context, more teacher involvement should be implemented.

Teacher appraisal and student feedback on teacher professional development and practices

Do Thanh Nhan, Nguyen Thanh Loan, Huynh Nguyen Bao Ngoc
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Nowadays, the number of English students is on the rise and English teachers need to be well-equipped with knowledge and flexibility so that they could have the best practices in their classroom. The teachers being appraised and getting feedback from students are able to adapt to different teaching contexts and to ensure that their students have profound understandings of what is taught thanks to increased teaching motivation and social recognition. The major aim of teacher appraisal and learner feedback is to develop teachers professionally in order to improve their delivery of lessons in schools. The effectiveness of the process of teacher appraisal and learner feedback is, however, dependent on the perceptions of the teachers themselves. Teacher appraisal gives teachers the motivation to move forward, but in some cases, it creates an invisible barrier for teachers as a result of their subjective thought. Likewise, feedback from students proved to be positive occasionally affects teachers in negative ways. With a view to addressing this problem, a study in this field was conducted with both qualitative and quantitative methods of research, which were employed to give the answers to the mentioned question, namely questionnaires and interviews. These instruments were delivered to 7 high school teachers, 18 English teachers and 100 students at an English language centre in Can Tho. The study aimed to identify whether teachers develop profession and accordingly assist English teachers in realizing how appraisal affects teachers’ feeling and how to adjust their practices in the real settings exposed to learner feedback.

Diversity of centipedes (Chilopoda: Scolopendromorpha and Scutigeromorpha) in Xuan Nha Nature Reserve, Son La province, Vietnam

Nguyen Duc Hung, Tran Thi Thanh Binh, Nguyen Thi Thanh Huyen, Dang Quoc Trung Chinh, Le Xuan Son
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This study on centipedes (Scolopendromorpha and Scutigeromorpha) was conducted in Xuan Nha Nature Reserve, Son La province in June and November 2018. A total of 47 specimens were collected from four types of habitats: broadleaf forest, broadleaf - bamboo mixed forest, bamboo forests, and residential - agricultural land. Data analysis results showed that a total of 14 species and subspecies was recorded in the study region. Of which, the order Scolopendromorpha has 12 recorded species and subspecies belonging to four genera (Cryptops, Paracryptops, Otostigmus,and Scolopendra), two families (Cryptopidae and Scolopendridae). The order Scutigeromorpha has only two species belonging to two genera (Thereuopoda and Thereuonema) and one family (Scutigeridae). All habitats has medium diversity of centipedes (1.00 < H’ < 3.00).  Broadleaf forest has the highest diversity (H' = 2.11), lower in mixed forest (H’ = 1.97) and bamboo forest (H’ = 1.61), residential - agricultural land has the lowest diversity (H’ = 1.01). The highest density is in mixed forest (1.2 individuals/m2), followed by broadleaf forest (0.8 individuals/m2), and bamboo forest (0.20 individuals/m2). Those are the first data of centipedes in Xuan Nha Nature Reserve.