Tidal Asymmetry and Suspended-Sediment Transport in the Gironde Estuary (FRANCE)

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

3-D numerical simulation of the tidal circulation in the Gulf of Tonkin, Vietnam

The purpose of this paper is to present 3-D numerical simulation of the tidal circulation in the Gulf of Tonkin. A sigma-coordinate system transformation is used to make possible a total fitting between the computing point-grid and the bottom topography as well as the free water surface. A turbulence-closure sub-model K-L which permits the parameterization of the turbulence mixing is also included. The studied domain, the whole Gulf of Tonkin, extends from the coastal zone of Quang-Ninh into Thua Thien Hue province and as far as Hai-Nam (China) island seawards. The model have been calibrated and verified by the observed data at six different stations for a three and seven-day periods. The results are in good agreement with the observed data. The kinetic energy distribution was considered

Effect of Molecular Charge Asymmetry on Even-to-odd Ratio of High-order Harmonic Generation

Recently, asymmetric molecules, such as HeH$_2^+$, CO, OCS, HCl, have been evolved much attention since its rich information in the high-order harmonic generation (HHG), whose ratio of adjacent even and odd harmonics characterizes the asymmetry of molecules. In this paper, we study the dependence of even-to-odd ratio on the asymmetric parameters, in particular, the nuclear-charge ratio, and the permanent dipole, by exploiting a simple but general model of asymmetric molecules $Z_1Z_2$ subjected to an intense laser pulse. The HHG is simulated by the numerical method of solving the time-dependent Schrödinger equation. We find out that this even-to-odd ratio strongly depends on the nuclear-charge ratio. In particular, the even-to-odd ratio reaches its maximum when the nuclear-charge ratio is about from 0.5 to 0.7. Besides, the dependence on the permanent dipole of the even-to-odd ratio has a non-trivial law. To explain, we calculate the analytical ratio of the transition dipole according to the emission of even and odd harmonics, and this ratio is well consistent with the even-to-odd ratio of the HHG

TYPES OF POLITENESS STRATEGIES AND DEGREES OF POLITENESS PERFORMED BY ENGLISH MAJOR STUDENTS IN REQUESTING FOR HELP

In social interaction, people need to pay attention to the face of others to maintain relationships and avoid losing their faces. To do this, people should use politeness strategies in communication. This study aims to investigate which type of politeness strategies are mostly used and the level of politeness shown by English major students in the High Quality Program in requesting help. This study is based on the theory of Brown and Levinson (1987). Based on the analysis of the data obtained from the questionnaire, negative politeness strategies were applied the most. This also performs a high degree of politeness. It shows that students majoring in English studies (High Quality Program) had an awareness of using politeness strategies in requesting help.<p> </p><p><strong> Article visualizations:</strong></p><p><img src="/-counters-/edu_01/0704/a.php" alt="Hit counter" /></p&gt

Improving indigenous Vietnamese Black Rabbit frozen sperm quality: the role of glycine and sperm selection methods

[EN] Rabbit sperm are known to undergo damage during both cryopreservation and thawing, leading to decreased viability, motility and membrane integrity. Glycine can protect sperm and reduce damage during freezing. Swim-up is a simple semen processing method for selecting good motile sperm. The study evaluated the effect of the swim-up method and glycine with different concentrations supplemented to the frozen medium. Three indigenous black rabbits were selected for semen collection by artificial vagina. Next, semen was selected by swim-up method and diluted with glycine-added frozen medium. The samples were then transferred to 0.5 mL straws, cooled to 15°C and 5°C, placed in liquid nitrogen vapour, and finally placed directly into liquid nitrogen (-196°C). The samples were thawed and evaluated for sperm quality. The results showed that the medium supplemented with 10mM glycine in combination with swim-up method for 30 min gave the best results and was significantly different from the remaining concentrations (P<0.01), with viability rate, overall mobility and membrane integrity of 68.0%, 58.7% and 49.7%, respectively. In conclusion, 10 mM glycine concentration combined with swim-up for 30 min is the optimal choice for freezing local black rabbit semen. The study highlights the importance of optimising freezing protocols to improve the quality of frozen rabbit sperm, which can have important implications for animal breeding and conservation efforts.This study is funded in part by the Can Tho University, Code: T2022-133Tran, TTT.; Duy, NLK.; Hang, NT.; Ngoc, PK.; Tuyen, DND. (2023). Improving indigenous Vietnamese Black Rabbit frozen sperm quality: the role of glycine and sperm selection methods. World Rabbit Science. 31(4):229-236. https://doi.org/10.4995/wrs.2023.1969022923631

Different loop arrangements of intramolecular human telomeric (3+1) G-quadruplexes in K(+) solution

Intramolecular G-quadruplexes formed by the human telomeric G-rich strand are promising anticancer targets. Here we show that four-repeat human telomeric DNA sequences can adopt two different intramolecular G-quadruplex folds in K(+) solution. The two structures contain the (3+1) G-tetrad core, in which three G-tracts are oriented in one direction and the fourth in the opposite direction, with one double-chain-reversal and two edgewise loops, but involve different loop arrangements. This result indicates the robustness of the (3+1) core G-quadruplex topology, thereby suggesting it as an important platform for structure-based drug design. Our data also support the view that multiple human telomeric G-quadruplex conformations coexist in K(+) solution. Furthermore, even small changes to flanking sequences can perturb the equilibrium between different coexisting G-quadruplex forms

WATER QUALITY STATUS OF WHITE LEG SHRIMP FARMING AREAS IN BINH DAI DISTRICT, BEN TRE PROVINCE, VIETNAM

This study focused on water quality assessment of farmed shrimp ponds in Binh Dai District, Ben Tre Province. The goals of the study were to provide chemical parameters of pond water for farmers, to identify problems and causes in farmed shrimp related to water quality and disease, and to help managers find appropriate solutions to minimize damage to local shrimp farming. Water samples were collected monthly from January to June 2021 from 90 vannamei farmers in six different areas, including Vang Quoi Dong, Dinh Trung Binh Thoi, Phu Long, Phu Vang, and Binh Thang of Binh Dai District. Parameters investigated in this study included pH, alkalinity, NH4+, NH3, NO2- and three other minerals. Water quality parameters were analyzed based on APHA standard analysis methods. The results showed that the water quality of shrimp farming areas in Binh Dai fluctuated from time to time, and water quality parameters were suitable for vannamei shrimp farming. However, the concentration of NO2- was always higher than the permitted threshold. The results from cluster analysis and MANOVA testing showed that water quality of the shrimp farming areas in Binh Dai was significantly different (p < 0.05), especially NO2-, Ca, Mg and alkalinity. These findings suggest that farmers must apply proper solutions for water quality management in each farming area to maximize crop production