THE EFFECTS OF MIND MAPPING AT WHILE-READING STAGE ON EFL STUDENTS’ READING COMPREHENSION AT A LOCAL HIGH SCHOOL IN KIEN GIANG PROVINCE, VIETNAM

There is an increased attention to research into the use of mind mapping as a useful tool for enhancing students’ reading comprehension. However, few studies have been conducted to examine the effects of mind mapping at the reading stage on students’ reading comprehension within the Vietnamese context. This paper therefore investigates the effects of mind mapping on 11th graders’ reading comprehension and their attitudes towards this strategy. Participants in this study include 60 students at a local school in Kien Giang province. The data discussed in this paper include tests and interviews. The findings reveal that using mind mapping in the teaching process of reading texts had a moderate impact. Pedagogical implications for teachers and school administrators are presented.  Article visualizations

Antibacterial and Antioxidant Activity of Rhodomyrtus Tomentosa and Cinnamomum Zeylanicum Crude Extracts

The aim of this study was to investigate the extraction method for R. tomentosa and C. zeylanicum leaves and the evaluation of antibacterial and antioxidant activities of crude extracts. The results of the study showed that the active ingredients of crude extracts were clearly separated by Thin-layer chromatography and the presence of rhodomyrtone in R. tomentosa crude extract and cinnamaldehyde in C. zeylanicum crude extract. R. tomentosa crude extract was antibacterial activity against Staphylococcus aureus with 13.1 mm of inhibition zone, but is not effective against Salmonella Typhimurium. C. zeylanicum leaf extract did not show antibacterial activity on both S. aureus and S. Typhimurium. At a dilution of 1/2 of the R. tomentosa crude extract can completely inhibit S. aureus growth. This study also indicated the presence of antioxidant compounds such as flavonoids, tannins, phenols and terpenoids in C. zeylanicum and R. tomentosa crude extracts. The results showed that R. tomentosa and C. zeylanicum crude extracts should be used as a biotherapy alternative to antibiotic therapy. However, further study would be needed to investigate the antibacterial activity of crude extracts in vivo

Ohmic currents and pre-decoupling magnetism

Ohmic currents induced prior to decoupling are investigated in a standard transport model accounting both for the expansion of the background geometry as well as of its relativistic inhomogeneities. The relative balance of the Ohmic electric fields in comparison with the Hall and thermoelectric contributions is specifically addressed. The impact of the Ohmic currents on the evolution of curvature perturbations is discussed numerically and it is shown to depend explicitly upon the evolution of the conductivity.Comment: 8 pages, 4 included figure

Evolutionary tracks for Betelgeuse

We have constructed a series of non-rotating quasi-hydrostatic evolutionary models for the M2 Iab supergiant Betelgeuse ($\alpha~Orionis$). Our models are constrained by multiple observed values for the temperature, luminosity, surface composition and mass loss for this star, along with the parallax distance and high resolution imagery that determines its radius. We have then applied our best-fit models to analyze the observed variations in surface luminosity and the size of detected surface bright spots as the result of up-flowing convective material from regions of high temperature in the surface convective zone. We also attempt to explain the intermittently observed periodic variability in a simple radial linear adiabatic pulsation model. Based upon the best fit to all observed data, we suggest a best progenitor mass estimate of $20 ^{+5}_{-3} M_\odot$ and a current age from the start of the zero-age main sequence of $8.0 - 8.5$ Myr based upon the observed ejected mass while on the giant branch.Comment: 27 pages, 11 figures, Revised per referee suggestions, Accepted for publication in the Astrophysical Journa

Constraints on Early Star Formation and Mixing from Nucleosynthesis in Protogalactic clouds

We calculate the stochastic chemical evolution of pre-galactic clouds as a means to constrain the degree of mixing in the early Galaxy. We employ a model based upon the cold-dark-matter paradigm for hierarchical galaxy formation. We argue that a significant dispersion in the metallicity for the alpha elements as a function of heavy elements is unavoidable for models with realistic stellar nucleosynthesis yields and a reasonable initial mass function. Although the calculated scatter in light-element abundance can be reduced by restricting the stellar initial mass function. The observed lack of dispersion requires inevitably requires that extensive mixing of the supernova eject containing alpha elements to have occurred. We use the difference between the observed and calculated dispersion of alpha to determine the degree of mixing of the early Galaxy. We argue that the large dispersion for heavy r-process elements suggests that they arise from rare events which did not have time to mix during the formation of the Galactic halo

Development of a diagnostic scar marker for Vibrio shilonii caused acute hepatopancreatic necrosis disease in whiteleg shrimp

Background: In a previous report, we showed that Vibrio shilonii was found on whiteleg shrimp (Litopenaeus vannamei) with acute hepatopancreatic necrosis disease in Thua Thien Hue province, Vietnam. This study was performed to develop a diagnostic molecular marker generated by random amplified polymorphic DNA (RAPD) for V. shilonii rapid detection.Methods: Pathogen Vibrio spp. were isolated from shrimps and fishes, and were identified by 16S rRNA sequencing. Genetic diversity of Vibrio strains was analysis by RAPD technique. Specific PCR product for V. shilonii was cloned and sequenced. SCAR marker was developed from specific PCR product.Result: Twenty random primers were evaluated for RAPD to identify DNA polymorphisms between Vibrio species. The random primer OPN-06 generated a 468-bp DNA fragment specific for V. shilonii. This was then converted into a sequence-characterized amplified region (SCAR) marker designated N6-441.Conclusion: Specific primers (Vshi-441F/Vshi-441R) amplified a unique DNA fragment in all V. shilonii isolates but not in the other Vibrio spp. This PCR assay showed significantly sensitive to the target DNA and reliably for the amplification the V. shilonii genome.Keywords: AHPND; RAPD; SCAR; Vibrio shilonii; Vietna

Using learning games for fourth-grade students to teach Vietnamese lessons and teachers' perspectives on learning games

Students can learn   in   a   meaningful way through the use of educational games. When students apply their skills and information in order to progress through a game, a huge degree of engagement is generated among them in the classroom as a result both their capabilities and their learning   increase. 153 children from primary schools in Vietnam participated in this research. The children were split into two groups: an experimental and a control group. Both groups participated in two sessions of word and sentence practice as well as spelling instruction. According to the findings of the study, the educational outcomes of the students are greatly improved when games are used in their classrooms. In addition, research has shown that some teachers are against the use of games in the classroom since it makes it more difficult to prepare educational materials. Some educators believe that playing educational games is a more effective method of instruction as it allows for greater flexibility during the learning process. This makes a contribution to the theoretical framework that is necessary to guide educators and instructors in the process of improving learning game programs for children in primary schools and other learners