STUDENTS’ EXPERIENCES ON LEARNING LISTENING THROUGH TECHNOLOGY-BASED TOOL

Using technology tools in the classroom can now be facilitated students' engagement and self-directed learning to support a learner-centred environment in educational contexts under varied perspectives. In language learning, evaluating a particular language skill focused on technology is crucial in students' experience. EFL students face several difficulties as noise, accent, vocabulary, and pronunciation while listening. Therefore, employing listening with technology is significantly necessary to enhance students' listening skills. However, rare research has provided the students' reflection under constructivist perspectives after studying with the technology-based listening tool. Thus, the current study narrows this empirical gap. Semi-structured interviews and observation were instruments employed to collect data. Using thematic analysis (Braun and Clarke, 2006), the results of this study indicated that five themes were individualised listening, collaborative learning, self-directed learning, consideration of errors, and pronunciation improvement. Students were more engaged when listening to tasks independently, considering their errors for further improvement, and self-directed learning in this study. Additionally, they mostly perceived themselves to improve their listening and pronunciation in the future. Teachers should pay close attention to speakers' voices, accents, and feedback when designing and implementing tasks to maximise learners' listening learning process. This study has implications on using BookWidgets as a potential pedagogical tool for English courses.  Article visualizations

Online learning negotiation: Native-speaker versus nonnative speaker teachers and Vietnamese EFL learners

Online English language teaching can now be facilitated by communication technology, which allows easy access to interaction with native speakers. Nevertheless, this industry subscribes to an assumption that native speaker English teachers (NESTs) are the gold standard of language whereas the non-native speaker English teachers (NNESTs) are inferior educators (Walkinshaw & Duong, 2014). Rare research has provided evidence of the negotiation produced by NESTs versus NNESTs with EFL learners online and its impact on the learners’ output. Thus, the current study narrows this empirical gap. Drawing upon a database of 30 five-minute interaction sessions between 30 teachers (15 NESTs and 15 NNESTs) and 30 basic level Vietnamese EFL adult learners, the study revealed similar negotiation of meaning functions as reported in previous research. However, the NESTs used more elaboration while the NNESTs used more confirmation checks, clarification requests, and reply clarification. Qualitative analysis further indicated that the NNESTs provided more productive support, encouraging the learners’ output, than the NESTs did. This implies that although online voice interaction creates an environment for EFL learners to practice, language educators and teachers, regardless of status, should heed how to handle it so that online learners can benefit from both comprehensible input and opportunities for pushed output

Research on Deep Learning-based Fractional Interpolation in Video Coding

Motion compensated prediction is one of the essential methods to reduce temporal redundancy in inter coding. The target of motion compensated prediction is to predict the current frame from the list of reference frames. Recent video coding standards commonly use interpolation filters to obtain sub-pixel for the best matching block located in the fractional position of the reference frame. However, the fixed filters are not flexible to adapt to the variety of natural video contents. Inspired by the success of CNN in super-resolution, we propose Convolutional Neural Network-based fractional interpolation for Luminance (Luma) and Chrominance (Chroma) components in motion compensated prediction to improve the coding efficiency. Moreover, two syntax elements indicate interpolation methods for the Luminance and Chrominance components, have been added to bin-string and encoded by CABAC using regular mode. As a result, our proposal gains 2.9%, 0.3%, 0.6% Y, U, V BD-rate reduction, respectively, under low delay P configuration.

A Research on Enhancing Reconstructed Frames in Video Codecs

A series of video codecs, combining encoder and decoder, have been developed to improve the human experience of video-on-demand: higher quality videos at lower bitrates. Despite being at the leading of the compression race, the High Efficiency Video Coding (HEVC or H.265), the latest Versatile Video Coding (VVC) standard, and compressive sensing (CS) are still suffering from lossy compression. Lossy compression algorithms approximate input signals by smaller file size but degrade reconstructed data, leaving space for further improvement. This work aims to develop hybrid codecs taking advantage of both state-of-the-art video coding technologies and deep learning techniques: traditional non-learning components will either be replaced or combined with various deep learning models. Note that related studies have not made the most of coding information, this work studies and utilizes more potential resources in both encoder and decoder for further improving different codecs.In the encoder, motion compensated prediction (MCP) is one of the key components that bring high compression ratios to video codecs. For enhancing the MCP performance, modern video codecs offer interpolation filters for fractional motions. However, these handcrafted fractional interpolation filters are designed on ideal signals, which limit the codecs in dealing with real-world video data. This proposal introduces a deep learning approach for all Luma and Chroma fractional pixels, aiming for more accurate motion compensation and coding efficiency.One extraordinary feature of CS compared to other codecs is that CS can recover multiple images at the decoder by applying various algorithms on the one and only coded data. Note that the related works have not made use of this property, this work enables a deep learning-based compressive sensing image enhancement framework using multiple reconstructed signals. Learning to enhance from multiple reconstructed images delivers a valuable mechanism for training deep neural networks while requiring no additional transmitted data.In the encoder and decoder of modern video coding standards, in-loop filters (ILF) dedicate the most important role in producing the final reconstructed image quality and compression rate. This work introduces a deep learning approach for improving the handcrafted ILF for modern video coding standards. We first utilize various coding resources and present novel deep learning-based ILF. Related works perform the rate-distortion-based ILF mode selection at the coding-tree-unit (CTU) level to further enhance the deep learning-based ILF, and the corresponding bits are encoded and transmitted to the decoder. In this work, we move towards a deeper approach: a reinforcement-learning based autonomous ILF mode selection scheme is presented, enabling the ability to adapt to different coding unit (CU) levels. Using this approach, we require no additional bits while ensuring the best image quality at local levels beyond the CTU level.While this research mainly targets improving the recent video coding standard VVC and the sparse-based CS, it is also flexibly designed to adapt the previous and future video coding standards with minor modifications.博士（工学）法政大学 (Hosei University

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

EGG QUALITY COMPARISON OF TWO VIETNAMESE CHICKEN BREEDS (RI AND MIA)

In the context of the valorization of poultry biodiversity, this work represents a step toward a better knowledge of the production abilities of local chicken breeds in Vietnam. Local chicken breeds are indeed particularly well suited for low-input rearing systems, as widely practiced in rural households of Vietnam. The socio-economic importance of these breeds might be underpinned by a market valorization through the mounting of differentiated quality value chains. Such a strategy needs the production potential of these local breeds to be assessed using parameters of egg quality and quantity. This study presents data about egg quality traits in two chicken breeds, the Ri and the Mia. The former is the most widespread breed in Vietnam, while the latter is known to be in danger of extinction. Nineteen parameters of quality of ninety eggs of Ri chickens and sixty eggs of Mia chickens were measured, each for both 40 and 60-weeks old hens to take hens ages into account.Mean egg weight of Mia eggs (44.70g) was significantly (p<0.001) higher than that of Ri eggs (41.68g). The yolk to albumen ratio was not significantly different (p>0.05) between the two breeds at the age of 40 weeks (Ri: 0.55; Mia: 0.58). For 60-weeks old hens, the ratio became significantly (p<0.05) higher in Mia eggs compared to Ri eggs (0.64 vs. 0.57). No significant difference (p>0.05) was recorded between the two breeds for parameters used for egg freshness assessment (Haugh’s units and pH of albumen and yolk) or eggshell resistance (maximal breakage force). Despite the small sample available for the study (due to the low availability of Mia hens and eggs), significant differences in egg quality traits were thus observed between these two breeds.Peer reviewe

Incidence of dengue and chikungunya viruses in mosquitoes and human patients in border provinces of Vietnam

Background: Dengue virus remains a major threat in Vietnam, while chikungunya virus is expected to become one. Surveillance was conducted from 2012 to 2014 in Vietnam to assess the presence of dengue and chikungunya viruses in patients hospitalized with acute fever in five Vietnam provinces neighboring Lao PDR and Cambodia. Surveillance was extended to mosquitoes present in the vicinity of the patients' households. Results: A total 558 human serum samples were collected along with 1104 adult mosquitoes and 12,041 larvae from 2250 households. Dengue virus was found in 17 (3%) human serum samples and in 9 (0.8%) adult mosquitoes. Chikungunya virus was detected in 2 adult mosquitoes (0.18%) while no chikungunya virus was detected in humans. Differing densities of mosquito populations were found, with the highest in the Long An Province border with Cambodia. Long An Province also displayed the lowest rate of infection, despite a very high Breteau Index, high human population density and presence of the main cross border road system. The highest incidence was found in Dac Nong Province, where the Breteau and Container indices were the second lowest. Dengue virus was detected in five Aedes albopictus, three Aedes aegypti and one Culex vishnui. Chikungunya virus was detected in two Ae. aegypti. All infected mosquitoes belonged to haplotypes described in other parts of the world and a number of novel haplotypes were found among uninfected mosquitoes. Conclusions: Dengue is considered to be regularly introduced to Vietnam from Cambodia, mostly through human movement. The data reported here provides a complementary picture. Due to intensive international trade, long-distance transportation of mosquito populations may play a role in the regular importation of dengue in Vietnam through Ho Chi Minh City. It is important to decipher the movement of mosquitoes in Vietnam, not only at the Lao PDR and Cambodia borders but also through international trade routes. Mosquito surveillance programs should address and follow mosquito populations instead of mosquito species

Spatiotemporal evolution of SARS-CoV-2 Alpha and Delta variants during large nationwide outbreak of COVID-19, Vietnam, 2021

We analyzed 1,303 SARS-CoV-2 whole-genome sequences from Vietnam, and found the Alpha and Delta variants were responsible for a large nationwide outbreak of COVID-19 in 2021. The Delta variant was confined to the AY.57 lineage and caused >1.7 million infections and >32,000 deaths. Viral transmission was strongly affected by nonpharmaceutical interventions

Meningitis patients with Angiostrongylus cantonensis may present without eosinophilia in the cerebrospinal fluid in northern Vietnam.

BACKGROUND: Eosinophilic meningitis (EM) is a rare clinical syndrome caused by both infectious and noninfectious diseases. In tropical pacific countries, Angiostrongylus cantonensis is the most common cause. However, the EM definition varies in the literature, and its relation to parasitic meningitis (PM) remains unclear. METHODOLOGY/PRINCIPAL FINDINGS: Adult and adolescent patients of 13 years old or above with suspected central nervous system (CNS) infections with abnormal CSF findings were prospectively enrolled at a tertiary referral hospital in Hanoi, Vietnam from June 2012 to May 2014. Patients with EM or suspected PM (EM/PM) were defined by the presence of either ≥10% eosinophils or an absolute eosinophil cell counts of ≥10/mm3 in the CSF or blood eosinophilia (>16% of WBCs) without CSF eosinophils. In total 679 patients were enrolled: 7 (1.03%) had ≥10% CSF eosinophilia, 20 (2.95%) had ≥10/mm3 CSF eosinophilia, and 7 (1.03%) had >16% blood eosinophilia. The patients with ≥10% CSF eosinophilia were significantly younger (p = 0.017), had a lower body temperature (p = 0.036) than patients with ≥10/mm3 CSF eosinophilia among whom bacterial pathogens were detected in 72.2% (13/18) of those who were tested by culture and/or PCR. In contrast, the characteristics of the patients with >16% blood eosinophilia resembled those of patients with ≥10% CSF eosinophilia. We further conducted serological tests and real-time PCR to identify A. cantonensis. Serology or real-time PCR was positive in 3 (42.8%) patients with ≥10% CSF eosinophilia and 6 (85.7%) patients with >16% blood eosinophilia without CSF eosinophils but none of patients with ≥10/mm3 CSF eosinophilia. CONCLUSIONS: The etiology of PM in northern Vietnam is A. cantonensis. The eosinophil percentage is a more reliable predictor of parasitic EM than absolute eosinophil count in the CSF. Patients with PM may present with a high percentage of eosinophils in the peripheral blood but not in the CSF