Published: 2023-11-22
Cover & Content
Phytotoxicity activities and chemical composition of the seed essential oil of Monodora myristica
Abstract
|
PDF
The phytotoxic effect of essential oil from African nutmeg (Monodora myristica) seeds on growth of tomato (Solanum lycopersicum L)., maize (Zea mays), and cowpea (Vigna unguiculata) was examined. Essential oil from the seeds of M. myristica was extracted by hydrodistillation. The essential oil’s composition was examined by gas chromatography-mass spectrometry (GC-MS). The phytotoxicity of the essential oil formulation at different concentrations for five days was evaluated on the leaves and roots. The activity was ascertained by estimating the shoots’ and the roots’ lenght. The result of GC-MS showed α–phellandrene (43.2%) as the essential oil's main constituent. The essential oil reduced the growth of the root and shoot of tomato, maize, and cowpea. At 4 mL/L treatment, the percentage inhibition of roots ranged from 63.8 to 75.4% after five days, while that of the shoot was 100% after three days. A varying toxicity was reported on the leaves of the seedlings of the plants after 24 hours. Phytotoxic was more potent on the leaves of cowpea and lowest in tomato. Phototoxic activity was also noted when essential oil was administered to the Seedling’s roots. The three species showed notable phytotoxicity when exposed to the essential oil of M. myristica.
Characterization of single nucleotide polymorphisms in chloroplast genomes of Musaceae Juss.
Abstract
|
PDF
Musaceae Juss., also called the bananas and plantains family contains essential food crops with critical economic value and nutritional and medicinal properties. In this study, complete chloroplast genomes of 55 species of Musaceae, including all three genera of Musa, Musella, and Ensete, were used to characterize single nucleotide polymorphisms. Also, nucleotide diversity among surveyed species was observed. The results showed regions of high genetic variability in the chloroplast genome and genes carrying multiple single-nucleotide polymorphisms specific for species and genera, such as ycf1, ycf2, ndhF, matK, accD, infA, and petL. A biased nucleotide conversion toward G, C, and T suggests a trend in the evolution of the Musaceae chloroplast genomes. Phylogenetic analysis revealed a close relationship between Ensete and Musella genera and confirmed the existence of two clades in the genus Musa. This study summarizes nucleotide diversity, focusing on single-nucleotide polymorphisms, which are helpful for further studies on population genetics and developing molecular markers in Musaceae.
Effects of seed soaking and foliar spraying of Kalanchoe pinnata aqueous leaf extracts against rice bacterial leaf blight
Abstract
|
PDF
This study aims at evaluating the disease-reducing effects against rice bacterial leaf blight (Xanthomonas oryzae pv. oryzae). Under greenhouse conditions, the activities of the four enzymes [peroxidase (POX), catalase (CAT), polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL)] after application of Kalanchoe pinnata aqueous leaf extracts using the combination of seed soaking and foliar spraying were studied. Overall, two extract concentrations [1 and 2% (w/v)] applied as seed soaking combined with the five extract concentrations [1, 2, 3, 4 and 5% (w/v)] applied as foliar spraying were tested. Three application methods were furthermore used for foliar spraying (7 days before pathogen inoculation (DBI), 14 DBI and their combination). Results showed the effects increased with the increase of extract concentrations and durations from application time points prior to pathogen inoculation. The combination of foliar spraying at 7 and 14 DBI provided stronger protection compared to single sprays. The effects involved induced resistance. Indeed, the activities of POX and CAT increased until 4 days after inoculation (DAI) and remained until 7 DAI, while those of PPO and PAL increased similarly then decreased until 7 DAI. Activities of these enzymes increased after pathogen inoculation and reached higher levels with extract applications.
Study of the activation of Truc Thon ball clay by acids
Abstract
|
PDF
Natural clay minerals have attracted attention for their availability and economical cost as adsorbents in the treatment of contaminants in aquatic environments. In this study, Truc Thon white ball clay from Hai Duong province, Vietnam was activated by different acids including H2SO4, HCl and H3PO4 at 110°C from 6 to 18 hours under refluxing conditions. The chemical composition and structure changes before and after the activation of the clay were characterized by X-ray fluorescence, X-Ray Diffraction and Fourier transform infrared spectroscopy. The raw clay is mainly composed of minerals containing alumina and silica while in activated clay, silica is dominant in amorphous phase. The specific area of clay particles was increased significantly after acid treatment from 10.55 m2.g-1 to 178.53 m2.g-1. Images from a scanning electron microscope also reveal more porous structure of activated clay. These behaviors make acid activated clay highly effective in various adsorption applications.
Preparation and characterization of magnetic-lignin nanoparticles with potential applications for drug delivery
Abstract
|
PDF
This study successfully combined Fe3O4 nanoparticles (made by co-precipitation technique) and lignin (extracted from sugarcane bagasse) as magnetic-lignin nanoparticles. The factors affecting the synthesis such as ratio of Fe3O4/lignin and reaction time were investigated. Fe3O4@lignin nanoparticles were obtained at optimal conditions, including the ratio between Fe3O4 and lignin of 1:0.5 and the reaction time of 9 hours. The resulting nanoparticles were spherical and had a fairly uniform particle size distribution, with an average diameter of 53.42 ± 5.12 nm (obtained from SEM images). The thermal stability of Fe3O4/lignin nanoparticles is quite stable and lignin content in hybrid Fe3O4/lignin particles is estimated to account for about 32.82%. FTIR results show a successful combination of Fe3O4 and lignin. The magnetic saturation of Fe3O4/lignin nanoparticles was determined by a vibrating sample magnetometer (VSM) with values of 50.8 emu.g-1, showed that the material keeps its super-paramagnetic properties, which is critical for their application in drug delivery field.
Review of the effects of Task-based Language Teaching on EFL learners’ speaking performance: What remains to be researched?
Abstract
|
PDF
Given the research trend on task-based language teaching (TBLT), several reviews have been conducted on its effects. However, no review has explored specific skills. This study aims to review previous studies with a focus on the improvement of EFL learners’ speaking performance. The main purpose is to reveal a gap for future study. Using the systematic review approach, we selected 25 qualified studies from different databases. Results showed that TBLT implementation promoted both general speaking and speaking components (i.e., complexity, accuracy, and fluency). Most of the studies either employed or adapted Willis’ model. The present study suggests that future research could explore the comparative effects of various task-based methodological options. Moreover, the text-driven approach to task design and implementation can be further researched to enhance EFL learners’ engagement and speaking performance.
Using lesson study for teacher development: A case study of Vietnamese EFL teachers’ reflections
Abstract
|
PDF
In this article, we present a case study of four Vietnamese teachers of English in a Community College working in a Lesson Study group that prepared them for teacher development in teaching English as a foreign language (EFL). Qualitative data from interview, reflective writing and observation were analyzed during the researched lessons. By conducting Lesson Study, the teachers indicated they were fully aware of the important roles of Lesson Study in their professional development strategies. They declaimed Lesson Study, involving a small group of educators collaboratively designing, teaching, and refining a single lesson could provide a platform for mutual learning, collaboratively designing more effective lesson plans which focus on learning goals, and rendering timid teachers more confident in having their teaching observed by colleagues. However, some constraints faced by the teachers were identified, which may undermine the gains of Lesson Study.
Career preferences of Filipino senior high school students
Abstract
|
PDF
This research determined the trends and challenges in career preferences of the public high schools in Cebu City, Philippines. The study participants were 35 students, including five guidance counselors and advocates (GCA) from different identified public national high schools. This research used a quantitative-qualitative mixed design through a focused group discussion to confirm the responses of the respondents. The results show that students often choose careers that suit the needs of their families. Sometimes, they use Facebook, LinkedIn, Twitter, and My Space to seek a job, base their choices in popular courses/degrees today, they even use technology to do that or choose a career that fits their abilities. According to the GCAs, most of the students lack motivation and do not know the deeper reasons for the courses that they want and just pick a degree program just for the sake of having one. Sometimes, they lack information about different careers, base things on practicality, they cannot decide, they do not have a choice and their parents choose their career for them. The findings suggest GCAs need to encourage learners, and their parents to make use of a career pathing design for them to be guided in terms of their career decisions.
Prevalence and antibiotic resistance of Staphylococcus aureus isolated from Pangasius fish and fish processing handlers in the Mekong Delta, Viet Nam
Abstract
|
PDF
This study aimed to investigate the prevalence and antibiotic resistance of Staphylococcus aureus isolates from Pangasius fish (Pangasianodon hypophthalmus) and the hands of fish processors in fish processing plants. The results showed that 16 of 90 Pangasius fish (18%) and 6 of 54 fish processing handlers’ samples (11%) harbored coagulase-positive for S. aureus. A high antibiotic resistance (68%) was observed for ampicillin, while 100% susceptibility for oxacillin, cefazolin, cefmetazole, flomoxef, imipenem, arbekacin, fosfomycin, and sulfamethoxazole-trimethoprim were recorded for both fish and hand samples. Remarkably, only one isolates from the fish was classified as methicillin-resistant S. aureus, whereas no isolates from the handlers were found. Among the total S. aureus isolates, the multidrug resistance rate was nearly 41%, posing a hazard to public health concerns. The obtained results may provide valuable information about the actual state of S. aureus contamination for efficient control in fish processing plants.
A legal perspective on child support obligation after divorce: The Vietnamese case
Abstract
|
PDF
Parents are legally obligated to pay child support; if they do not live with their child Upon divorce. The obligation to support the child following a divorce is a central provision of Viet Nam's 2014 Marriage and Family Act and a significant aspect of family law. It is the responsibility of both parents and the government to safeguard children. However, the 2014 Act on Marriage and Family still needs to improve its provisions regarding child support obligations, such as the absence of a minimum quantity and a starting date. This article investigates the historical periods and regulations governing child support obligations in Viet Nam compared to other nations. This study also evaluates the practical applicability of the current legal provisions and identifies their deficiencies. This study intends to recommend modifications to child support laws that will help protect children's rights following parental divorce.
Synergistic and antagonistic medicinal activities of essential oil of Monodora myristica
Abstract
|
PDF
Synergetic and antagonistic medicinal activities of crude and fractionated essential oil from the seed of Monodora myristica were investigated. The crude essential oil was extracted by steam distillation and then subjected to column chromatography; three fractions (N1, N2, and N3) were obtained. To identify the components, gas chromatography and mass spectrometry (GC-MS) investigation was utilized. The phytochemical parameters were determined by standard analytical methods. 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) were used to evaluate the antioxidative capacity. and, the anti-diabetic activity was performed using α-amylase and α-glucosidase assay. The Agar diffusion method was used to determine the antibacterial activities. The GC-MS analysis indicated p-cymene (21.12%) as the major component of the crude essential oil. The antioxidant activity using DPPH varied from 614 to 704 µg/mL, while the ABTS activity ranged between 281-342 µg/mL. The α-amylase assay showed fraction N1 with IC50 value of 3.21 µg/mL, while for α-glucosidase assay, fraction N2 with IC50 2.15 µg/mL recorded the least value. The minimum inhibitory concentration values for the crude extract and all the fractions against the strains of bacteria ranged from 6 to 12.5 mg/mL Both crude extract and fractionated essential oil showed antioxidant, anti-diabetic and antibacterial activities.
1,3,4-Oxadiazole derivatives as potent antifungal agents: Synthesis, biological evaluation and an in silico study
Abstract
|
PDF
Ten 1,3,4-oxadiazole derivatives were prepared and evaluated for their anti-fungal activities. The results showed that compounds 4a, 7a, and 7f displayed activity against F. oxysporum. Molecular docking study indicated that compounds 4a, 7a, and 7f exhibited affinity towards F. oxysporum’s β-tubulin by showing low binding energies as well as interactions with the key amino acids in the binding sites of the receptor.