DICHLODIPHENYLTRICHLOETHANES (DDTS) RESIDUES IN TAM GIANG-CAU HAI AND LANG CO LAGOONS, VIETNAM

Joint Research on Environmental Science and Technology for the Eart

Asymmetric Impacts of Public Debt on Economic Growth: Empirical Evidence From Vietnam

Purpose: The objective studies the influence of government debt on the expansion of the Vietnamese economy was the subject of the research presented in this article.   Theoretical framework: Most governments in developing nations have budget deficits due to excessive spending and inadequate revenue. When the government chooses to pay the budget deficit through borrowing, it incurs a liability known as public debt and public debt on economic growth.   Design/methodology/approach: In regression analysis involving time series data, if the regression model contains the variables' present values and the lagged values (past values), this model is known as the lagged distribution model. If the model's explanatory variables include one or more lagged values of the dependent variable, the model is called the autoregressive model. Nonlinear Auto Regressive Distributed Lag regression was applied.   Findings: The findings reveal that government debt has a considerable and disproportionate effect on sustained economic growth in the short and long run using a Nonlinear Autoregressive Distributed Lag (NARDL) model with quarterly data over twenty years beginning in 2000.   Research, Practical & Social implications: The results indicate a disproportional association between public sector debt levels and short- and long-term economic growth. The results are consistent with recent empirical studies showing a nonlinear relationship between some nations' public debt and economic development.   Originality/value: Government debt should support short- and long-term economic growth through funding production. Consequently, government debt should not burden the economy when the high amount of debt exceeds the capacity to repay

Selection of suitable fragment from rbcL gene for DNA barcode analysis of family Halymeniaceae, Rhodophyta

Among the members of Halymeniaceae family, Grateloupia sensu lato occupies the largest composition in species. Classification based on morphological traits is difficult due to the highly variable terete to blade-like thalli among the members of this genus that usually leads to misidentification. Molecular systematics has been applied to classify Grateloupia sensu lato so that the taxonomists acquire a better understanding of the species diversity in general. The plastid gene encoding the large subunit of ribulose-1,5-bisphosphate-carboxylase-oxygenase (rbcL) was the focus of numerous marine algal studies concerning phylogeny and molecular evolution. However, using the full length of rbcL showed disadvantages such as cost and time consuming due to two times of sequencing and two times of PCR. In the present study, the shorter sequence, fragment 773 bp at 5’ end and fragment 579 bp at 3’ end of rbcL were applied and compared for the phylogenetic analysis of Halymeniaceae members. The results indicated there are no differences of topological phylogenetic trees, species resolution within genus and genus resolution within the family between fragment 773 bp at 5’ and the full length of rbcL. Therefore, we conclude that fragment 773 bp at 5’ should be used as DNA barcodes for the Halymeniaceae to reduce the cost and time during phylogenetic analysis. Two taxa Grateloupia newly collected in Vietnam were grouped to the known Phyllymenia, a new genus in Vietnam

Teachers’ Perceptions of Active Learning Techniques in Teaching Speaking: A Case at Language Centers in the Mekong Delta

This paper reports a descriptive study that explored teachers’ perceptions of implementing active learning techniques in teaching speaking and the challenges teachers encountered in their teaching practices in their speaking classes. Participants were 56 teachers from different language centers in the Mekong Delta, Vietnam. The data were collected through questionnaires and semi-structured interviews. The findings of the study revealed that the majority of the teachers had positive perceptions of the implementation of active learning techniques in teaching speaking. They also expressed the advantages they gained as well as the difficulties they faced when implementing active learning techniques in their speaking classes. Keywords: perceptions, active learning, speaking skills DOI: 10.7176/JEP/14-10-02 Publication date: April 30th 202

Preconcentration of Arsenic Species in Environmental Waters by Solid Phase Extraction Using Metal-loaded Chelating Resins

Joint Research on Environmental Science and Technology for the Earth『Annual Report of FY 2002, The Core University Program between Japan Society for the Promotion of Science (JSPS) and National Centre for Natural Science and Technology (NCST)』pp.20-23, Core University Program Office, Fujita Laboratory, Dept. of Environmental Engineering, Osaka University, 200

About the edge-based smoothed finite element method for the Reissner-Mindlin plate-bending problem

The paper further develops the edge-based smoothed finite element method (ES-FEM) for analysis of Reissner-Mindlin plates using triangular meshes. The bending and shearing stiffness matrices are obtained using strain smoothing technique over the smoothing domains associated with edges of elements. Transverse shear locking can be avoided with help of the discrete shear gap (DSG) method. The numerical examples show that the present ES-FEM-DSG method obtains very accurate results compared to the exact solution and other existing elements

Effect of Hydrolysis on Tannin and Carotenoid Contents, and Antioxidant Activity of Pouteria campechiana

The medicinal properties of Pouteria campechiana fruit in Vietnam currently have not been studied much. This study was conducted to evaluate hydrolysis's effect on the carotenoid, tannin, and antioxidant activity through the correlation between IC50 and TPC values of Pouteria campechiana extract. This study examined hydrolysis conditions, such as enzyme type, enzyme concentration, temperature, and hydrolysis time. Experimental results showed that at pectinase enzyme concentration of 0.6 wt%, cellulase enzyme concentration of 0.6 wt%, at hydrolysis temperature of 600C, and 65 minutes for hydrolysis, the study found carotenoid of 115.14±4.14 (µg/g) and tannin of 45.88±2.37 (mgTAE/g)in the extract. IC50 value (7.82±0.21 mg/mL) and TPC content were highly correlated (R2=0.98). This study's results contributed to the provision of valuable scientific data on Pouteria campechiana fruit, especially for the food industr