THE PERCEIVED EFFECTS OF TEST-TAKING STRATEGIES INSTRUCTION ON EFL HIGH SCHOOL STUDENTS' MULTIPLE-CHOICE TESTS OF READING COMPREHENSION

This study aims to investigate whether the use of a text-taking strategy could enhance EFL high school learners' reading comprehension. It draws on the test-taking strategies suggested by Cohen and Upton (2007), to focus on the two main aspects, (1) the influence of applying test-taking strategies on EFL high school students’ reading comprehension tests and (2) their attitudes toward these strategies. In the pretest-posttest one-group design and descriptive quantitative research, the reading comprehension test and the questionnaire were used to collect the data of 90 EFL high school students in a school in rural Can Tho City. These students were assigned to apply test-taking strategies in a workshop every week in the second Semester of 2021-2022. The findings showed that (1) participating students’ reading comprehension scores improved after following the test-taking strategies after 07 weeks; and (2) students were positive about their being active in their testing practice despite certain challenges. As a result of such positive attitudes, they had high motivation for continuing their practice test-taking strategies for the future examination.  Article visualizations

Growth and development of transgenic peanut (Arachis hypogaea) lines containing chitinase 42 kDa gene from Trichoderma asperellum SH16

Peanut (Arachis hypogaea L.) is vulnerable to many diseases. Vietnam and other regions where peanut is widely cultivated have a high threat of fungal and other plant diseases. Various fungicides are available to control the fungal disease but these have various harmful effects on the natural flora, fauna, and environment. Transgenic peanut lines which possess antifungal activity provide a possible solution in managing fungal diseases apart from the traditional resistance and fungicide usage. Therefore, this study evaluated the probable growth and development of chitinase transgenic peanut lines against Sclerotium rolfsii, a pathogen that causes “southern blight” in plants, under greenhouse conditions. This study provided evidence that through Agrobacterium itumefaciens mediated transformation, 42 kDa chitinase genes from Trichoderma asperellum, which is under the regulation of 35S promoter, were successfully incorporated into the peanut’s (A. hypogaea L.) genome and expressed in their plants. This evidence also demonstrated that transgenic peanut lines were suitable for growing and developing in the greenhouse. Further, it was reported that transgenic peanut lines took approximately 133 to 145 days from planting to maturity. These results also revealed that various growth characteristics of transgenic peanut lines having two synthetic genes (syncod Chi42-2 i.e. S2-2, S2-4, S2-6, and syncod Chi42-1 i.e. S1-1, S1-2, S1-3) were greater than that from the wild-type Chi42 (WT-1, WT-2, and WT-3). In addition, yield-related parameters including the number of mature pods, 100 pods weight and 100 seeds weight for all the transgenic peanut lines were higher than that of the non-transformed plant. Among the transgenic lines, line S2-4 exhibited significantly higher growth and yield than the other transgenic lines. These results demonstrated that 42 kDa chitinase genes overexpressing peanut lines could be a candidate for improvement against plants to phytopathogenic fungus S. rolfsii and high yield.

Improving indigenous Vietnamese Black Rabbit frozen sperm quality: the role of glycine and sperm selection methods

[EN] Rabbit sperm are known to undergo damage during both cryopreservation and thawing, leading to decreased viability, motility and membrane integrity. Glycine can protect sperm and reduce damage during freezing. Swim-up is a simple semen processing method for selecting good motile sperm. The study evaluated the effect of the swim-up method and glycine with different concentrations supplemented to the frozen medium. Three indigenous black rabbits were selected for semen collection by artificial vagina. Next, semen was selected by swim-up method and diluted with glycine-added frozen medium. The samples were then transferred to 0.5 mL straws, cooled to 15°C and 5°C, placed in liquid nitrogen vapour, and finally placed directly into liquid nitrogen (-196°C). The samples were thawed and evaluated for sperm quality. The results showed that the medium supplemented with 10mM glycine in combination with swim-up method for 30 min gave the best results and was significantly different from the remaining concentrations (P<0.01), with viability rate, overall mobility and membrane integrity of 68.0%, 58.7% and 49.7%, respectively. In conclusion, 10 mM glycine concentration combined with swim-up for 30 min is the optimal choice for freezing local black rabbit semen. The study highlights the importance of optimising freezing protocols to improve the quality of frozen rabbit sperm, which can have important implications for animal breeding and conservation efforts.This study is funded in part by the Can Tho University, Code: T2022-133Tran, TTT.; Duy, NLK.; Hang, NT.; Ngoc, PK.; Tuyen, DND. (2023). Improving indigenous Vietnamese Black Rabbit frozen sperm quality: the role of glycine and sperm selection methods. World Rabbit Science. 31(4):229-236. https://doi.org/10.4995/wrs.2023.1969022923631

Some triterpenoids and steroids from Bruguiera cylindrica leaves collected from Can Gio mangrove forest

Bruguiera cylindrica (Rhizophoracea), distributed in the Southeast Asia, has been used as a traditional medicine in the treatment of diarrhea and healing of wounds. Some triterpenoids and steroids were isolated from the dried leaves of Bruguiera cylindrica, collected at Can Gio mangrove forest, Ho Chi Minh City, including lupeol (1), 3β-hydroxyoleana-9(11),12-diene (2), a mixture of stigmasterol (3a) and b-sitosterol (3b), cholesta-4-ene-3-one (4) and 3β-hydroxycholesta-5-ene-7-one (5). Their chemical structures were elucidated by spectroscopic analysis as well as comparing their data with the ones in the literature. Although these compounds were known in other plants this is the first time they are reported in this species. Keywords. Bruguiera cylindrica, triterpenoids, steroids

Using metagenomics tool to evaluate the enrichment efficiency of methanogens in marine sediment in Truong Sa archipelage, Khanh Hoa province, Vietnam

Methanogens (archaea bacteria that produce methan) play an important role in the anaerobic digestion of organic waste, however, in marine environment, the low density of methanogens makes anaerobic digestion very slow. In this study, we used methagenomics tool to evaluate the enrichment efficiency of methanogens communities in marine sediments as a basis for building a anaerobic microbial formulation to treat organic waste in marine environment. The results of determination of methanogen density by MPN method have shown that methanogen has been accumulated with higher density (up to 3.2.107 MNP/ml) through 2 times of enrichment in artificial seawater with CH3COONa 10 mM substrate. In addition, metagenomics data have also shown a decrease in the number of archaea species through each enrichment, indicating that methanogenic species have gradually dominated the microbial community. This is the first study on using metagnenomics tools to evaluate the enrichment of methanogens in marine sediment samples in Truong Sa archipelago, Vietnam. Metagenomics data help provide more reliable evidence in microbial studies, especially in obligate anaerobes such as methanogens

Determination of the Administration Routes, Doses and Appropriate Age to Vaccinate With Ornitin Triple Vaccine For Cross-breed Colored Broilers in Vietnam

The study was to determine the appropriate dose and administration route of Ornitin Triple vaccine in cross-breed coloured broilers in Vietnam by evaluating the antibody titer against Ornithobacterium rhinotracheale (ORT) and local reactions at injection sites on chickens after vaccination. The study was divided into 2 trials. Both trials were designed with 3 vaccine dose groups: 0.0ml (control group), 0.25ml and 0.5ml and 2 different administration routes: subcutaneous at neck (SC) and intramuscular at breast (IM) injection. The result showed that, no statistically significant difference was found between antibody titer of two administration routes as well as 2 vaccine doses until 13-week-old. Local reactions at the injection sites of IM route was less severe than SC at neck and in higher dose would produce a more severe swelling reaction. Daily weight gain was found to have a slight decrease in the vaccinated groups within 2 weeks after vaccination, however, no statistically significant difference was found in later stage (P > 0.05). In conclusion, Ornitin Triple can be used to vaccinate by IM with the dose of 0.25ml for coloured broilers at early age (3-week-old), or 0.5ml for older birds and should be careful for some reactions at the injection sites

Spatial distribution of Culex mosquito abundance and associated risk factors in Hanoi, Vietnam

Japanese encephalitis (JE) is the major cause of viral encephalitis (VE) in most AsianPacific countries. In Vietnam, there is no nationwide surveillance system for JE due to lack of medical facilities and diagnoses. Culex tritaeniorhynchus, Culex vishnui, and Culex quin-quefasciatus have been identified as the major JE vectors in Vietnam. The main objective of this study was to forecast a risk map of Culex mosquitoes in Hanoi, which is one of the most densely populated cities in Vietnam. A total of 10,775 female adult Culex mosquitoes were collected from 513 trapping locations. We collected temperature and precipitation information during the study period and its preceding month. In addition, the other predictor variables (e.g., normalized difference vegetation index [NDVI], land use/land cover and human population density), were collected for our analysis. The final model selected for estimating the Culex mosquito abundance included centered rainfall, quadratic term rainfall, rice cover ratio, forest cover ratio, and human population density variables. The estimated spatial distribution of Culex mosquito abundance ranged from 0 to more than 200 mosquitoes per 900m2. Our model estimated that 87% of the Hanoi area had an abundance of mosquitoes from 0 to 50, whereas approximately 1.2% of the area showed more than 150 mosquitoes, which was mostly in the rural/peri-urban districts. Our findings provide better insight into understanding the spatial distribution of Culex mosquitoes and its associated environmental risk factors. Such information can assist local clinicians and public health policymakers to identify potential areas of risk for JE virus. Risk maps can be an efficient way of raising public awareness about the virus and further preventive measures need to be considered in order to prevent outbreaks and onwards transmission of JE virus

UV Light Induced Thermoluminescence of Rare Earth doped Nanomaterials Y2_2O3_3:Eu3+^{3+}, Gd2_2O3_3:Eu3+^{3+} and Gd2_2O3_3:Er3+^{3+}

Thermoluminescence  properties of ultraviolet irradiated Y2O3:Eu3+, Gd2O3:Eu3+ and Gd2O3:Er3+ nanophosphors have been reported. The materials were synthesized by gel- combustion method with EDTA- Na2 as organic agent. This method allows production of very fine white powder at low temperature with very high efficiency. XRD has been studied to determine the structure of the prepared nano powders. The obtained materials exhibit sufficient sensibility to UV radiation and may be useful in UV light measurements

OVERVIEW OF ARSENIC CONTAMINATION IN GROUNDWATER AND HUMAN HEALTH RISK IN VIETNAM

Joint Research on Environmental Science and Technology for the Eart