Diversity of plant-parasitic nematodes on medicinal plants in Melinh station for biodiversity, Vinh Phuc Province, Vietnam

Plant-parasitic nematodes are known as one of the most important pests attacking various plants in the world, and investigating the nematode component is very essential for management of this pest and prevent damage to plants in general. Our survey of plant-parasitic nematodes on medicinal plants in Melinh Station for Biodiversity, a place for conservation of precious plants and animals in Vietnam, identified ten species that belong to nine genera, five families, and two orders of plant-parasitic nematodes parasitizing six medicinal plants. Excoecaria cochinchinensis was parasitized by the highest number of nematode genera (5 genera, including Xiphinema, Discocriconemella, Meloidogyne, Helicotylenchus, and Hemicriconemoides), while Hymenocallis littoralis was associated with the highest number of plant-parasitic nematodes (2060 nematodes/250g soil). The results also showed that Discocriconemella limitanea was found to be a dominant species with the highest number of individuals on 6 medicinal plants, and the genus Helicotylenchus had the highest frequency of appearance (5/6 plants or 83.3%). These nematodes caused symptoms such as yellowing leaves, root galls, and root lesions, which directly affect the quality and yield of medicinal plants. Based on the results, this study showed that plant-parasitic nematodes are a potential threat to the cultivation of medicinal plants in Melinh Station for Biodiversity, and thus, control measures should be applied to ensure sustainable cultivation of medicinal plants in this place

Impact of Frequency Shift on Nonlinear Compensation Using Optical Phase Conjugation for M-QAM Signals

Nonlinear compensation using optical phase conjugation (OPC) have been considered a promising technique to increase the reach of high-speed fiber-optic transmission systems. OPC-based nonlinear compensation employs an optical phase conjugation located at a middle of the fiber link to generate a complexed conjugated signal with respect the signal in the first half of the link for propagation in the second half. OPC technique assumes a symmetry for signal propagating in the first and second half to obtain a perfect nonlinear and chromatic dispersion. However, as most of practical OPC schemes are realized by nonlinear effects such as four-wave mixing or a combination of second-harmonic generation and difference frequency generation, the frequency shift induced by OPC affects the signal symmetrical requirement for nonlinear compensation because the chromatic dispersion is different for the first and second half transmissions. In this paper, we investigate the impact of frequency shift on the nonlinear compensation using OPC for high symbol rate, high level modulation format signals. This will be important to understand the tolerance of the OPC techniques against such a practical condition for actual system implementations

A Hybrid Photorealistic Architecture Based on Generating Facial Features and Body Reshaping for Virtual Try-on Applications

Online shopping using virtual try-on technology is becoming popular and widely used for digital transformation because of sustainably sourced materials and enhancing customers’ experience. For practical applicability, the process is required for two main factors: (1) accuracy and reliability, and (2) the processing time. To meet the above requirements, we propose a state-of-the-art technique for generating a user’s visualization of model costumes using only a single user portrait and basic anthropometrics. To start, this research would summarize different methods of most virtual try-on clothes approaches, including (1) Interactive simulation between the 3D models, and (2) 2D Photorealistic Generation. In spite of successfully creating the visualization and feasibility, these approaches have to face issues of their efficiency and performance. Furthermore, the complexity of input requirements and the users’ experiments are leading to difficulties in practical application and future scalability. In this regard, our study combines (1) a head-swapping technique using a face alignment model for determining, segmenting, and swapping heads with only a pair of a source and a target image as inputs (2) a photorealistic body reshape pipeline for direct resizing user visualization, and (3) an adaptive skin color models for changing user’s skin, which ensures remaining the face structure and natural. The proposed technique was evaluated quantitatively and qualitatively using three types of datasets which include: (1) VoxCeleb2, (2) Datasets from Viettel collection, and (3) Users Testing to demonstrate its feasibility and efficiency when used in real-world application

Lattice-Reduction-Aided Detection with Successive Interference Cancelation for Multiuser Space-Time Block Coded Systems

Effective detectors with low-complexity are considered for the Alamouti’s multiuser space-time block coded (STBC) systems. Viewing the noiseless received signals from Q users as a lattice with basis vectors being the columns of the total channel matrix H, we apply lattice reduction to transform the original basis into a nearly orthogonal one which improves the decision regions against noise. Then, linear detection using zero-forcing (ZF) and minimum-mean-square-error (MMSE) methods is performed on the transformed basis to detect transmitted signals from the Q users. These lattice-reduction-aided (LRA) linear detectors significantly improve BER of the linear detectors and, more importantly, allow us to achieve full diversity at high Eb/N0 regions

Sub-optimal Deep Pipelined Implementation of MIMO Sphere Detector on FPGA

Sphere detector (SD) is an effective signal detection approach for the wireless multiple-input multiple-output (MIMO) system since it can achieve near-optimal performance while reducing significant computational complexity. In this work, we proposed a novel SD architecture that is suitable for implementation on the hardware accelerator. We first perform a statistical analysis to examine the distribution of valid paths in the SD search tree. Using the analysis result, we then proposed an enhanced hybrid SD (EHSD) architecture that achieves quasi-ML performance and high throughput with a reasonable cost in hardware. The fine-grained pipeline designs of 4 × 4 and 8 × 8 MIMO system with 16-QAM modulation delivers throughput of 7.04 Gbps and 14.08 Gbps on the Xilinx Virtex Ultrascale+ FPGA, respectively

OPTIMIZING THE PRODUCTION OF A FUNCTIONAL TYPE A RECOMBINANT ENDOCHITINASE FROM Trichoderma asperellum IN Escherichia coli

Chitinases from the genus Trichoderma fungi are mainly responsible for their anti-fungal activities, which allow them to become the most widely used fungal biocontrol. Therefore, several Trichoderma chitinases have been cloned and expressed to facilitate their production and applications. A previous study of the same authors has characterized an endochitinase from a relatively novel Trichoderma spp., Trichoderma asperellum. To produce this enzyme more economically and efficiently, we reported the synthesis and expression of its synthetic encoding gene in the Escherichia coli M15 strain and established the optimal conditions for preparative scale production of the enzyme in its functional form. By lowering the induction temperatures, we observed substantial improvement in the expression levels of the active enzyme.  At 30 oC and 0.5 mM IPTG induction, 1 L of cells yielded approximately 80 - 100 mg of soluble protein, accounting for about 9-11 % of total soluble protein. This figure may be an underestimation of the actual yield, as deduced from the SDS-PAGE data. The recombinant enzyme can be retrieved by simple repeated freezing and thawing cycles and purified to near homogeneity using Ni-NTA chromatography. The purified enzyme showed in vitro colloidal chitin hydrolysis activity. These results could be scaled up to produce soluble 42 kDa chitinase in E. coli. The study demonstrated an economical method to produce chitinases for various agricultural and environmental applications

A potential low cost medium for cultivation of Dunaliella salina DCCBC15 in Vietnam

Dunaliella salina is a marine alga with high potential for beta-carotene (pro-vitamin A), up to more than 10% of cellular dry weight under appropriate stress conditions of limiting one of the following nutrients: nitrogen, phosphate, high light or high salt. Obtaining high biomass in low cost medium is the essential step of the two-phase culture system for beta-carotene production. For future development of beta-carotene production from Dunaliella in Vietnam, it is our first step to study a low cost medium using natural seawater enriched with industrial fertilizer N-P-K (30-15-10) commercially available in Vietnam. The primary results of biomass, cell density, chlorophyll a as well as growth rate are very promising to use this medium for mass culture of Dunaliella salina. The medium is recommended for growing other marine algae as well

Enhanced Adsorption of Methylene Blue by Chemically Modified Materials Derived from Phragmites australis Stems

In this study, the biomass of Phragmites australis was chemically modified using NaOH and subsequently citric acid to produce an effective adsorbent named SA-RPB. The absorbent was characterized using XRD, SEM, BET, and FT-IR methods. The study's findings indicated that the adsorbent existed mainly as cellulose crystals, contained micropores with an average diameter of 15.97 nm, and had a large number of hydroxyl and carboxyl groups on the surface. The adsorption process of SA-RPB was evaluated through the adsorption of methylene blue (MB) dye in aqueous solution. Adsorption kinetics showed that the pseudo-second-order model well described the adsorption process. The adsorption isotherm process satisfactorily fitted with the Langmuir model with the maximum adsorption capacity of 191.49 mg/g at 303 K. These findings show that MB may be efficiently removed from aqueous solutions using the adsorbent made from the raw biomass of Phragmites australis treated with NaOH and then citric acid

Arbitrary Form Plasmonic Structures: Optical Realization, Numerical Analysis and Demonstration Applications

Surface plasmon resonance has attracted more and more attention thanks to its wide range of applications in numerous fields (physics, chemistry, biology, etc.). In this chapter, we present different aspects, from theoretical calculation and experimental fabrication to applications demonstration, related to arbitrary shape plasmonic nanostructures. First, numerical calculations based on finite-difference time-domain method were realized to investigate the plasmonic properties of gold nanostructures having various size and shapes. Then the direct laser writing method was demonstrated as an excellent tool for fabrication on demand of arbitrary nanostructures. Plasmonic structures were obtained indirectly by a standard lift-off method from a polymeric template and directly by tightly focusing a continuous-wave laser beam onto a metallic thin film. Finally, demonstration of various applications of fabricated plasmonic structures, namely plasmonic-based data storage, color nanoprinter, tunable filters, and plasmonic-magneto-optics sensors will be shown