Vietnam Academy of Science and Technology: Journals Online
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Coral reef fishes in the coastal waters of Ninh Thuan province
No full textThis study was conducted to evaluate the species composition and distribution of coral reef fish communities at 24 sites in three areas Ninh Hai, Phuoc Dinh, and Ca Na in Ninh Thuan province from 2018 to 2019. A total of 301 species belonging to 131 genera and 49 families of coral reef fishes were recorded. Among them, the wrasse (Labridae: 55 species), the damselfish (Pomacentridae: 46 species) and the butterflyfish (Chaetodontidae: 26 species) occupy the three highest proportion. The average density of coral reef fish in coastal waters of Ninh Thuan province is 106.8 ± 23.4 individuals/100 m2, most of them are small sized fish and ornamental fish groups. Ninh Hai has a higher species richness and density than other areas. Meanwhile, Ca Na and Phuoc Dinh have the two highest densities of the large sized fish and food target fish groups. This research also points out the impact of monsoon on the density and distribution of coral reef fish, in which Ninh Hai is most affected
Molecular Emissions from Circumstellar Envelopes in the Presence of a Binary Companion
No full textFollowing our previous work on the hydrodynamic simulations of the structure of circumstellar envelopes in the presence of a binary companion, in this paper we present the results of radiative transfer calculations for molecular emission line HC3N J=5 – 4 from these simulated circumstellar envelopes. We show that the molecular line emission traces closely the spiral pattern and the associated density enhancement induced by the presence of the binary companion. The molecular emission provides the spatial kinematics of the features within the envelope, which is valuable for estimating the orbital parameters of the binary system and for inferring the physical conditions of the gas within the envelope. We also show that the appearance of the molecular emission depends on the viewing angle resulting in a range of shapes from the spiral pattern to ring-like features, similar to that observed recently in a number of circumstellar envelopes at high angular resolution
NDSHA - The New Paradigm for RSHA - An Updated Review
No full textA New Paradigm (data driven and not like the currently model driven) is needed for Reliable Seismic Hazard Assessment RSHA. Neo-Deterministic Seismic Hazard Assessment (NDSHA) integrates earthquake geology, earthquake science, and particularly earthquake physics to finally achieve a New (and needed) Paradigm for Reliable Seismic Hazard Assessment RSHA.Although observations from many recent destructive earthquakes have all confirmed the validity of NDSHA’s approach and application to earthquake hazard forecasting-nonetheless damaging earthquakes still cannot yet be predicted with a precision requirement consistent with issuing a red alert and evacuation order to protect civil populations. However, intermediate-term (time scale) and middle-range (space scale) predictions of main shocks above a pre-assigned threshold may be properly used for the implementation of low-key preventive safety actions, as recommended by UNESCO in 1997. Furthermore, a proper integration of both seismological and geodetic information has been shown to also reliably contribute to a reduction of the geographic extent of alarms and it therefore defines a New Paradigm for TimeDependent Hazard Scenarios: Intermediate-Term (time scale) and Narrow-Range (space scale) Earthquake Prediction.
First record of Xiphinema hunaniense Wang & Wu, 1992 (Dorylaimida: Longidoridae) associated with tea (Camellia sinensis (L.) Kuntze) in Thanh Hoa, Vietnam
No full textThe dagger nematodes, Xiphinema spp., are migratory root-ectoparasitic nematodes that cause damage to a wide range of wild and cultivated plants over the world. In Vietnam, this nematode group has been studied mainly based on morphological characterizations. During a survey of pathogens associated with tea, a plant with many medicinal and therapeutic potentials, a population of Xiphinema hunaniense was recorded. This study provides the first morphological and molecular characterizations of Xiphinema hunaniense found on Tea in Vietnam. The 28S rDNA, and 18S rDNA phylogenetic trees of the genus Xiphinema are also provided. 18S rDNA sequence of X. hunaniense is also submitted to GenBank for the first time.
Study on the association of SLC2A9 rs16890979 with gout in 410 Vietnamese individuals
No full textGout is a common form of inflammatory arthritis caused by crystallization of acid uric in the joints. The development of gout is not only triggered by environmental factors but also by genetic variation of individuals. In this study, the association between the variation SLC2A9 rs16890979 and gout was investigated. Total DNA was extracted from 410 blood samples of 163 gout patients and 247 age-matched healthy controls. Genotypes of SLC2A9 rs16890979 were obtained using PCR-RFLP. Chi-Square test was used to test whether allele distribution of rs16890979 followed Hardy-Weinberg Equilibrium (HWE). Associations of the clinical characteristics between gout patient and control groups were assessed using Mann-Whitney U. Chi-Square test or Fisher’s exact test was used to check four models (additive, recessive, dominant, co-dominant) for association of rs16890979 with gout. The obtained results showed that the allele distribution of SLC2A9 rs16890979 was in accordance with HWE (p 0.05). Clinical characteristics such as triglyceride and creatinine were significantly different between gout patient and control groups. However, there was no association of rs16890979 with the risk of gout in Vietnamese population. Further study with a larger sample size should be implemented to confirm our results regarding the association of SLC2A9 rs16890979 with gout in the Vietnamese population. This study would help enrich the knowledge about the effects of hereditary factors on gout disease in the Vietnamese population.
Development of an ELAA kit to detect neomycin in milk
No full textAntibiotics used in livestock production offer various benefits as an antimicrobial agent, growth promoter, and feed effective improvement. However, the abuse of antibiotics leads to antibiotic resistance which may seriously threaten human and animal welfare, and growing levels of antibiotics or antibiotic-resistant bacteria in the environment increase the numbers of drug-resistant infection outbreaks. Therefore, many detection methods have been being developed to quickly assess antibiotic content and its residues in foods. Among many analytical methods, the aptamer-based biosensor has considerable attention for its outstanding advantages such as high specificity, high sensitivity, and good selectivity. We use the ELAA (Enzyme-Linked Aptamer Assay) method - a variant of ELISA - which has a high affinity with neomycin. Firstly, we investigated different buffers to create the Neo-BSA complex. As result, 2-(N-morpholino) ethanesulfonic acid (MES) buffer pH 7 was found with the best results. Next, to help the Neo-BSA complex be fixed well on polystyrene wells, we surveyed various buffers and found the coating buffer (50mM Bicarbonate buffer, pH 9.6) rated as the most suitable for this process. In addition, the quality of the kit is also assessed through competitive ELAA reaction components. Therefore, we have investigated and optimized conditions such as aptamer concentration 25 nM in PBS buffer, and the biotinized aptamers did not need heat treatment prior to joining the reaction. From the results, we have successfully developed a calibration curve for antibiotic residue in milk using the ELAA technique, linear range 0,1 ng/mL and 100 ng/mL. Then, we initially surveyed 20 milk samples found that the ELAA method was consistent with the results from LC-MS/MS was obtained showing no difference between the two methods. We continued to test the samples to determine the kit’s sensitivity and specificity. The results showed that the kit has a specificity and sensitivity of 100%. Finally, LOD and LOQ value had xavg = 0.448; SD = 0.22, LOD = xavg + 3SD = 1.11 (ng / ml); LOQ = x tb + 10SD = 2.65 (ng / mL). We will continue to optimize the kit before being brought to the market
Economizing Nonlocal Resource in Two-Way Remote Preparations of Inequivalent Quantum States Under a Common Control
No full textA recently proposed protocol for two parties to securely and simultaneouslyexchange inequivalent quantum states under the same control of a third party[Int. J. Theor. Phys. (2020);https://doi.org/10.1007/s10773-020-04657-0] is revisited. It is shown inthis paper that the required tasks are equally well accomplished with anonlocal resource which is greatly economized by rationally exploiting localresources. Furthermore, the economized nonlocal resource with appropriatelocal operations on local resources also allows exchanging inequivalentstates other than those previously considered
IMPROVEMENT OF CONTROL ALGORITHM FOR MOBILE ROBOT USING MULTI-LAYER SENSOR FUSION
No full textMobile robots have received much of attention in the last three decades due to their very high potential of applications such as smart logistics, exploration, and intelligent services. One of important functions of mobile robots is the navigation in which robot must know their location, the maps of environment and perform path planning with obstacle avoidance. In this work, we introduce an improvement of control algorithm for mobile robot using multi-layer sensor fusion toward the target of efficient obstacle avoidance. Based on our method, we used three layers of sensors arranging in three height-different planes of robot’s housing for sensor fusion. A control algorithm, which is extended from the so-called bubble rebound algorithm and uses signal from sensor system, was proposed. Experimental implementation on a mobile robot, named EAI, shows that our algorithm can control the robot to navigate and avoid obstacles much efficiently, in which obstacles in forms of different shapes and height can also be avoided. A high repeatability and stability of the algorithm is obtained
Magnetic Domain Walls Moving in Curved Permalloy Nanowires under Continuous and Pulsed Fields
No full textMagnetic domain walls created and propagated in curved permally nanowires under continuous and pulsed fields in a Lorentz microscope. Using such nanowires aims to create a single or multiple magnetic domain walls in typical areas of those structures, an external magnetic field then applies along the long axis of these nanowires. Following that the created domain walls are propagated from one end to the other end of each wire by increasing the continuous/pulsed field strength. At each increased field value, a Fresnel image is recorded. The obtained results show that the characteristics of those created and propagated domain walls are dependent on various parameters, i.e. connecting structures, wall types and chiralities. Corners between the straight and linking sections of those curved nanowires also play a crucial role along witth the local defects created in these wire-edges and surfaces where a point-defect is considered as a potential well that could pin/distort those created/propagated domain walls. By the aid of this observations, the dynamic properties of domain walls with the creating and propagating processes in those curved nanowires are exposed. These outcomes are vital to design novel domain wall trap structures supporting reproducible domain wall motions. That are of interest in providing a better understanding of multiple bits moving in the furure 3D racetrack memory, logic gates, shift register and other spintronic/computing devices
PREPARATION AND ANALGESIC ACTIVITY TEST OF CAPSICUM FRUTESCENS OLEORESIN
No full textCapsaicin is an alkaloid in capsaicinoids group known as a spicy flavour ingredient in chilies and some pungent foods. Recently, capsaicin has been used not only as an additive in food but also as a medicine like analgesic, anticancer, and antidiabetic drug due to its’ pharmacological properties. In this study, capsicum oleoresin was extracted via heating chili powder, Capsicum frutescens (L.), with ethanol 80% at 70 °C in 120 minutes, then the extract was solvent evaporated in low pressure. Capsaicin was determined by thin-layer chromatography (TLC) and qualified by high-performance liquid chromatography (HPLC) method. Finally, the analgesic activity of capsicum oleoresin was tested on mice. The results show that capsicum oleoresin extracted from 2 kilograms of capsicum powder was 368.84 grams with 2.84% capsaicin. The central analgesic and peripheral analgesic effects of capsicum oleoresin were 90 minutes and 10-15 minutes after treatment, respectively