GROUP OF SUOI BA ARCHAEOLOGICAL SITES (DAK NONG PROVINCE): DOCUMENTS, PERCEPTION, AND DISCUSSION

This article introduces the results of investigations and surveys from 2006 to 2017 of the group of Suoi Ba archaeological sites in Nhan Co commune, Dak R’Lap district (Dak Nong). The results reveal eight prehistoric archaeological sites in the Suoi Ba area, which are distributed over an area of about 20 hectares, equivalent to the size of an ancient village, and date from 3,500 to 2,000 years BP. In this study, the authors systematize materials, assess historical-cultural values, briefly outline the prehistoric cultural process at Suoi Ba during the late Neolithic and early Metal Age in Dak Nong, and discuss issues related to Suoi Ba relics in a broader context

Discovering Water Quality Changes and Patterns of the Endangered Thi Vai Estuary in Southern Vietnam through Trend and Multivariate Analysis

Temporal and spatial water quality data are essential to evaluate human health risks. Understanding the interlinking variations between water quality and socio-economic development is the key for integrated pollution management. In this study, we applied several multivariate approaches, including trend analysis, cluster analysis, and principal component analysis, to a 15-year dataset of water quality monitoring (1999 to 2013) in the Thi Vai estuary, Southern Vietnam. We discovered a rapid improvement for most of the considered water quality parameters (e.g., DO, NH4, and BOD) by step trend analysis, after the pollution abatement in 2008. Nevertheless, the nitrate concentration increased significantly at the upper and middle parts and decreased at the lower part of the estuary. Principal component (PC) analysis indicates that nowadays the water quality of the Thi Vai is influenced by point and diffuse pollution. The first PC represents soil erosion and stormwater loads in the catchment (TSS, PO4, and Fetotal); the second PC (DO, NO2, and NO3) determines the influence of DO on nitrification and denitrification; and the third PC (pH and NH4) determines point source pollution and dilution by seawater. Therefore, this study demonstrated the need for stricter pollution abatement strategies to restore and to manage the water quality of the Thi Vai Estuary

Study on structure of the Earth’s crust in Thua Thien-Hue province and adjacent areas by using gravity and magnetic data in combination

This paper presents the structural characteristics of the Earth’s crust in Thua Thien-Hue province and adjacent area based on interpretation of gravity and magnetic data in combination. Research results have shown that: The depth of crystalline basement varies complicatedly, in the range of 0–11 km. The depth of Conrad surface increases from Northeast (12 km) to Southwest (18 km) and the depth of Moho surface is 23–34 km; The density of sedimentary layer changes from 2.61 g/cm3 to 2.65 g/cm3. Meanwhile, the density of granitic layer is in the range of 2.68–2.73 g/cm3. The basaltic layer has the density value of 2.88–2.93 g/cm3 and the average density of lower layer of the Earth’s crust is about 3.30 g/cm3; The depth of second-order faults, Red River and A Luoi - Rao Quan, is through the Earth’s crust. Meanwhile, the depth of influence of third-order faults, Chay river, Dong Ha - Phu Vang, Vinh Linh, Hue - Son Tra and Tam Ky - Phuoc Son, is within the thickness of the Earth’s crust

Academic Anxiety of Vietnamese Secondary School Students as a Reason for Applying Online Learning

Academic anxiety is one of the major problems in student psychology across the world. It applies equally to students of all ages, from elementary school to college and university students. Research shows that learning online is an effective way to defuse feelings of academic anxiety. Elimination of anxiety is clearly visible regardless of age, gender, or prior online learning experience. The study aims to identify academic anxiety as one of the most important reasons for moving to online learning or blended learning in secondary school. The study investigated academic anxiety among secondary school students in Vietnam. After surveying 677 students in classroom learning, the results showed that 13.7% of secondary students suffered from frequent anxiety, and 3.0% of them suffered from very frequent anxiety. Lower anxiety was observed among students actively participated in-class activities, and students with excellent academic performance. These factors can be optimally enhanced through blended and online learning. There were no differences in academic anxiety among male and female students, urban and rural students. There was a moderate correlation between a student's anxiety level and pressure of the school, parental expectations, students' motivation for high performance, and especially, among students who have the melancholic temperament. And the influence of these negative factors can also be optimally reduced with the help of online learning. Regression model could provide useful suggestions for parents, teachers and students in reducing academic anxiety for students, including the use of full or blended online learning

EmbryosFormer: Deformable Transformer and Collaborative Encoding-Decoding for Embryos Stage Development Classification

The timing of cell divisions in early embryos during the In-Vitro Fertilization (IVF) process is a key predictor of embryo viability. However, observing cell divisions in Time-Lapse Monitoring (TLM) is a time-consuming process and highly depends on experts. In this paper, we propose EmbryosFormer, a computational model to automatically detect and classify cell divisions from original time-lapse images. Our proposed network is designed as an encoder-decoder deformable transformer with collaborative heads. The transformer contracting path predicts per-image labels and is optimized by a classification head. The transformer expanding path models the temporal coherency between embryo images to ensure monotonic non-decreasing constraint and is optimized by a segmentation head. Both contracting and expanding paths are synergetically learned by a collaboration head. We have benchmarked our proposed EmbryosFormer on two datasets: a public dataset with mouse embryos with 8-cell stage and an in-house dataset with human embryos with 4-cell stage. Source code: https://github.com/UARK-AICV/Embryos.Comment: Accepted at WACV 202

Morphological characterization and classification of cassava (Manihot esculenta Crantz) in Vietnam

The aim of this study was to establish the morphological basis for the classification of major cassava cultivars (Manihot esculenta Crantz) planted in Vietnam. Twenty typical descriptors were observed in various specific growth stages. Four traits related to mature leaves and two traits related to leaf veins were detected in cassava plant after the 4-month stage. At the same time, 12 root- and stem-related descriptors were collected in cassava plants from 8-months to harvest. We found that two traits in the apical leaves can be observed in every growth stage. A classification tree based on these traits was constructed with 6 essential morphological descriptors to recognize the 7 most common cassava cultivars in Vietnam. KM 140 variety is distinguished by purplish-red in apical leaves, while KM 98-7 can be classified with straight or linear shapes of central leaflet. The irregular orientation of the petiole is a unique descriptor of local cultivar XVP. In the case of SM 937-26, weak foliar scars are observed. Finally, KM 94, KM 419, and KM 98-5 varieties can be classified by the color of the stem epidermis. These morphological descriptors will be a foundation to classify all cassava varieties planted in Vietnam.

Geo-chemical fractionations of arsenic and lead in the surface sediments of Thuy Trieu lagoon, Khanh Hoa province

The sequential extraction method of Tessier et al. was applied to identify the phase associations of As and Pb in the surface sediment of Thuy Trieu lagoon. The results showed that these two metals were mainly found in the residual fractions. Meanwhile, the carbonate fractions stayed at the lowest portions. Levels of arsenic and lead as Fe-Mn oxide fractions were higher than those as organic fractions and exchangeable fractions. Exchangeable fractions and carbonate fractions of two elements seemed to increase in rainy season. Generally, the mobility of Pb was higher than that of As. In the sediments of Thuy Trieu lagoon, Pb levels cannot currently cause adverse effects on the ecosystems. On the contrary, the risk of As was assessed as moderate level

Antibacterial Nanocomposites Based on Fe 3

For the vulcanized natural rubber (NR), incorporation of silver nanoparticles (AgNPs) into the NR matrix did not exhibit the bactericidal property against Escherichia coli (E. coli). However, incorporation of AgNPs into polyethylene (PE) matrix showed good antibacterial activities to both Gram-negative and Gram-positive bacteria. In the present work, NR/PE (85/15) blends have been prepared by melt blending with presence of compatibilizer in an internal mixer. To possess antibacterial property, AgNPs (5–10 nm) or Fe3O4–Ag hybrid nanoparticles (FAgNPs, 8 nm/16 nm) were added into PE matrix before its blending with NR component. The tensile test indicated that the presence of compatibilizer in NR/PE blend significantly enhanced the tensile strength and elongation at break (up to 35% and 38% increases, resp.). The antibacterial activity test was performed by monitoring of the bacterial lag-log growth phases with the presence of nanocomposites in the E. coli cell culture reactor. The antibacterial test showed that the presence of FAgNPs in NR/PE blend had a better antibacterial activity than that obtained with the lone AgNPs. Two similar reasons were proposed: (i) the faster Ag+ release rate from the Fe3O4–Ag hybrid nanoparticles due to the electron transfer from AgNP to Fe3O4 nanoparticle and (ii) the fact that the ionization of AgNPs in hybrid nanostructure might be accelerated by Fe3+ ions

Effects of calpastain (CAST) polymorphisms on carcass and meat quality traits in Mongcai pigs

Calpastain (CAST) activity plays a major role in muscle growth and proteolytic changes post-mortem and the CAST gene has been considered as a candidate gene for carcass and pork quality characteristics. The aim of this study was to analyze the association of two polymorphisms namely CAST_HinfI (allele A and B) and CAST_MspI (allele C and D) with carcass and meat quality traits in Mongcai, a Vietnamese indigenous pig breed. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to genotype the animals at these loci. Results indicate that the CAST_HinfI single nucleotide polymorphism (SNP) had a low frequency of allele A as compared to allele B, while the C and D allele distribution was almost the same for the CAST_MspI SNP. In the association analysis, significant effects on dressing percentage of carcass were detected. The CAST_HinfI locus was associated with the pH24, while the CAST_MspI position was in association with pH45 min, drip loss48 and redness color. Additional analysis showed a variation in muscle fiber type composition with higher proportion of IIx fiber in pigs with AB genotype (P < 0.05). Three constructed haplotypes namely AB/CD, AB/DD and BB/CC also had significant effects on carcass, type IIa and IIb fiber percentages.Keywords: Association, carcass, pork quality, Vietnamese local pi