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Foot rot disease caused by Phytophthora capsiciis one of the most destructive diseases of black pepper in Vietnam and worldwide. However, other oomycete species such as P. tropicalisand Pythium deliensereported as serious threats to black pepper in India have also been recorded on this plant. The population of oomycetes occurring in black pepper plantations in Vietnam and their pathogenicity have not been investigated in the last decade. To this end, two hundred fifteen oomycete isolates were collected from the root rots and rhizospheric soil of black pepper in the Central Highlands and the Southeast region of Vietnam. Of these, 23 isolates were representatively chosen based on their origin and morphology for DNA sequence analysis of the internal transcribed spacer region, then 11 isolates were further selected for the translation elongation factor 1-alpha and the beta-tubulin gene analyses. Morphology and molecular analyses indicated that P. capsici, P. cinnamomi, P. heveae, P. nicotianae, P. parvispora, P. tropicalis, Phytopythium vexans, and a new species candidate Phytopythiumsp. were identified among oomycete isolates. Of these, P. capsiciand P. tropicaliscould be the prevalent species in black pepper plantations in studied areas. The inoculation tests demonstrated that P. capsici, P. nicotianaeand P. tropicaliswere pathogenic on both leaves and roots of black pepper. Phytopythium vexanswas pathogenic on root only. Meanwhile, P. cinnamomi, P. heveae, P. parvisporaand Phytopythiumsp. were non-pathogenic.

In this work we introduce a new approach for solving equilibrium problems in a real Hilbert space. First, we propose a solution mapping and show its strong quasi-nonexpansiveness. Next, we apply the mapping to present an algorithm for solving equilibrium problems. Strong convergence of the algorithm is showed under quasimonotone and Lipschitz-type continuous assumptions of the cost bifunctions. Finally, we give some numerical results for the proposed algorithm and comparison with some other known methods using the solution mapping.

ABSTRACTBackgroundThis study was designed to assess the impact of postoperative atrial fibrillation (POAF) on short- and long-term outcomes after cardiac surgery.MethodsWe prospectively assessed POAF concerning outcomes in 379 adult patients who had undergone cardiac surgery in two heart surgery centers with a follow-up period of one year for every patient. The effects of POAF on postoperative events were evaluated using Logistic regression, Cox regression (adjusted for propensity score), and Kaplan-Meier analysis.ResultsThe incidence of POAF was 27.2%. Multivariable logistic regression analysis revealed POAF was associated with an increased risk of 6-month (OR = 5.36; CI: 1.51–18.94; p = 0.009), and 1-year mortality (OR = 4.56; CI: 1.29–16.04; p = 0.018) as well as Major Adverse Cardiocerebral Events (MACEs; acute MI, cardiac arrest, low cardiac output after surgery, third-degree atrioventricular block or stroke; OR = 3.02; CI: 1.29–7.05; p = 0.011), Intensive Care Unit (ICU) stay > 3 days (OR = 2.39; CI: 1.14–5.00; p = 0.021), and postoperative stay > 14 days (OR = 3.12; CI: 1.65–5.90; p < 0.001). Multivariable Cox regression analysis showed POAF as an independent predictor of mortality at one year (HR = 2.86; CI: 1.05–7.75; p = 0.038). Discharge plans including statin and beta-blocker had an independent association with a reduced mortality at one year (HR = 0.22; CI: 0.05–0.96; p = 0.045; HR = 0.16; CI: 0.03–0.87; p = 0.034, respectively).ConclusionsPOAF is associated with an increased risk of morbidity, all-cause mortality, and hospital duration. Statins and beta-blockers that were included in discharge plans had an independent association with reduction in 1-year all-cause mortality.

Recently, a regularized forward-backward dynamical system associated with additively structured monotone inclusions involving a multi-valued maximally monotone operator Aand a single-valued co-coercive operator Bhas been studied in Boţ et al. (Adv. Nonlinear Anal. 10, 450–476, 2021). In this work, we establish strong convergence of the generated trajectories to a solution of the original monotone inclusion under a weaker assumption on the operator B, namely Bis Lipschitz continuous and such that the sum S:=A+Bis maximally monotone. It is well known that the co-coerciveness of Bimplies its monotonicity and Lipschitz continuity, which in turn infers the maximal monotonicity of S. If the operator A+Bis maximally monotone and strongly pseudomonotone, we obtain a convergence estimate. A time discretization of the dynamical system provides an iterative regularization forward-backward method with relaxation parameters. The performance of the regularized dynamical system approach is illustrated by numerical experiments.

This paper provides a complete overview of the entire process of designing a welding head moving device and its implementation as a semi-automatic welding machine. The mechanical structure of the device is designed based on the size of the material pipe and the accompanying technical requirements. The system is equipped with an arc generator set and a rotary speed control unit allowing its use as an orbital welder.

In this paper, we construct Carathéodory type and exponential Carathéodory type schemes for Caputo stochastic fractional differential equations (CSFDEs) of order α∈(12,1)in Lpspaces with p≥2whose coefficients satisfy a standard Lipschitz and a linear growth bound conditions. The strong convergence and the convergence rate of these schemes are also established.

Workplace incivility has exerted negative influences on employees' well-being and led to lower service quality, the mechanism of which is yet fully explained by existing literature. This research aims to investigate the effects of three kinds of workplace incivility on frontline employees' capacity to satisfy customers using conservation of resources (COR) theory and propose psychological capital (PsyCap) as a moderator. A questionnaire was distributed to 608 frontline employees in Vietnam working in four service sectors. Both CB-SEM and PLS-SEM were employed using SPSS, AMOS and SmartPLS softwares to analyse the measurement and structural models. Incivility from customers, coworkers, and supervisors has significant negative influences on FLEs' capacity to satisfy customers that are partially mediated by emotional exhaustion and exhausted perceived organisational support. PsyCap partially moderates the effect of supervisor incivility on emotional exhaustion. The results recommend policies and intervention programs related to enhancing FLEs' PsyCap.

The study examines the effect of corporate governance and assurance auditing services on earnings management in the case of Vietnam. We investigate that higher earnings manipulation is associated with higher board meeting frequencies and CEO/board chair position separation. Moreover, the qualified assurance auditing service insignificantly negatively affects earnings management. This finding suggests that pre-eminent perspectives of corporate governance systems from developed economies may not be a good fit for emerging markets like Vietnam. Generally, our paper emphasises the importance of the Vietnam policymaker's role in building effective monitoring mechanisms in the capital market by disciplining and supervising listed companies' current corporate governance applications. In addition, it is essential that the quality of assurance auditing services need to be enhanced to improve the transparency level in the capital market.

In this paper, basing on the forward-backward method and inertial techniques, we introduce a new algorithm for solving a variational inequality problem over the fixed point set of a nonexpansive mapping. The strong convergence of the algorithm is established under strongly monotone and Lipschitz continuous assumptions imposed on the cost mapping. As an application, we also apply and analyze our algorithm to solve a convex minimization problem of the sum of two convex functions.

The PBAT (poly (butylene adipate-co-terephthalate) is a promising biodegradable material. However, it is often blend with hydrophilic polymers since its degradation rate in the aquatic environment is still limited. In this study, the blend PBAT/TPS (thermoplastic starch) films, namely BFs, were prepared by a blow extrusion approach, and evaluated for hydrolysis in four studied mediums acid (HCl, 1 M, 2 M, and 3 M), alkaline (NaOH, pH = 9, 11, and 13), phosphate buffer (pH = 7.4), and artificial seawater. The hydrolyzed BFs were characterized by weight loss, mechanical properties, scanning electron microscopy (SEM), Fourier transform infrared spectra (FTIR), and differential scanning calorimetry (DSC). A larger starch content in the BFs caused hydrolysis more quickly. The highest hydrolytic rate was found in the alkaline solution, followed by the acid medium. The complete abiotic hydrolysis of the BFs was 3 M HCl for 14 days or NaOH (pH 13) for 35 days. After 180 days of incubation, the film containing 70.5 % PBAT/TPS granules has been associated with the highest biodegradation rate of 76.31 % in composting.

In this study, we synthesized 5-alkyl/arylidene-2-(morpholin/thiomorpholin-4-yl)-1,3-thiazol-4(5H)-one through a one-pot reaction using all starting materials in a microwave oven. The presence of the solid base MgO catalyzed the reaction in the eco-friendly solvent of ethanol as a green chemistry approach owing to the noticeable advantages of short reaction times to save energy and less toxic starting materials for environmental friendliness. This indicates that the one-pot reaction makes the process simpler, in which the reaction time (1 h) is shorter than that of conventional methods (10 h). The yield of the reactions reached 55–76% for 18 final products consisting of 17 derivatives of morpholine or thiomorpholine with various aldehydes and one extended moiety of the primary amine, of which 13/18 final compounds were new. The purification procedure was performed without using polluting solvents. The structures were confirmed using IR, 1H-NMR, 13C-NMR, and MS analyses.

This paper uses multi-country, firm-level data covering 109 countries for the period 2005 to 2017, to examine the effects of bribery on export decisions for firms facing institutional constraints. Bribery consists of “greasing” and rent-seeking behavior. Firms’ self-evaluations of the extent of obstacles affecting their business operations, including corruption, political instability, tax administration, and business license regulations, were used to capture the institutional constraints. Our empirical results provide evidence to support the “greasing-the-wheels-of-trade” hypothesis. The positive effect of greasing bribery is particularly sizable for large-sized firms or those facing no institutional constraints. In other words, firms with strong bargaining power proxied by firm size obtain more benefits from paying bribes if there are no institutional constraints; thus, they are more likely to export. These results hold when we specify almost all types of institutional constraints except for political instability. Lastly, when the endogeneity problem is controlled, the effect of greasing bribery becomes pronounced.

The novel coronavirus (SARS-CoV-2) has infected several million people and caused thousands of deaths worldwide since December 2019. As the disease is spreading rapidly all over the world, it is urgent to find effective drugs to treat the virus. The main protease (Mpro) of SARS-CoV-2 is one of the potential drug targets. Therefore, in this context, we used rigorous computational methods, including molecular docking, fast pulling of ligand (FPL), and free energy perturbation (FEP), to investigate potential inhibitors of SARS-CoV-2 Mpro. We first tested our approach with three reported inhibitors of SARS-CoV-2 Mpro, and our computational results are in good agreement with the respective experimental data. Subsequently, we applied our approach on a database of ∼4600 natural compounds, as well as 8 available HIV-1 protease (PR) inhibitors and an aza-peptide epoxide. Molecular docking resulted in a short list of 35 natural compounds, which was subsequently refined using the FPL scheme. FPL simulations resulted in five potential inhibitors, including three natural compounds and two available HIV-1 PR inhibitors. Finally, FEP, the most accurate and precise method, was used to determine the absolute binding free energy of these five compounds. FEP results indicate that two natural compounds, cannabisin A and isoacteoside, and an HIV-1 PR inhibitor, darunavir, exhibit a large binding free energy to SARS-CoV-2 Mpro, which is larger than that of 13b, the most reliable SARS-CoV-2 Mpro inhibitor recently reported. The binding free energy largely arises from van der Waals interaction. We also found that Glu166 forms H-bonds to all of the inhibitors. Replacing Glu166 by an alanine residue leads to ∼2.0 kcal/mol decreases in the affinity of darunavir to SARS-CoV-2 Mpro. Our results could contribute to the development of potential drugs inhibiting SARS-CoV-2.

ASEAN (The Association of SouthEast Asian Nations) demand on energy is depending on economic growth of each country, resources, and political and regulations of each country. This study aims to investigate the role of international trade, financial development, foreign direct investment (FDI) on the consumption of renewable energy (RE) in ASEAN countries of the world. The findings explore that positive nexus among the international trade, real output, financial development, foreign direct investment and consumption of RE. Last but not least, this paper will propose several recommendations and policy suggestion for ASEAN countries to manage and encourage better renewable energy projects in the region. One of its original value is that, in the globalization and integration era, environment pollution will affect all ASEAN countries and in the region, so these nations need to link together to implement renewable projects for environment pr otection and for further generation.

ABSTRACTThis paper examines firms’ asset volatility across a broad cross-section of publicly traded Taiwanese listed nonfinancial firms and its relationship with effective tax rate and equity volatility under the capital structure framework. By analysing the leverage effect hypothesis of firms under the asymmetric diagonal VECH-GJR model, we find both equity volatility and asset volatility do not show the asymmetric effect. In the context of equity volatility dynamics, financial leverage turns from being negatively related to equity volatility to being positively related to equity volatility when the model adds asset volatility as a control variable. Moreover, lower equity volatility is found to be associated with higher effective tax rates.

ABSTRACTQuercetin is a flavonol belonging to the flavonoid group of polyphenols. Quercetin is reported to have a variety of biological functions, including antioxidant, pigment, auxin transport inhibitor and root nodulation factor. Additionally, quercetin is known to be involved in bacterial pathogen resistance in Arabidopsisthrough the transcriptional increase of pathogenesis-related(PR) genes. However, the molecular mechanisms underlying how quercetin promotes pathogen resistance remain elusive. In this study, we showed that the transcriptional increases of PRgenes were achieved by the monomerization and nuclear translocation of nonexpressor of pathogenesis-related proteins 1 (NPR1). Interestingly, salicylic acid (SA) was approximately 2-fold accumulated by the treatment with quercetin. Furthermore, we showed that the increase of SA biosynthesis by quercetin was induced by the transcriptional increases of typical SA biosynthesis-related genes. In conclusion, this study strongly suggests that quercetin induces bacterial pathogen resistance through the increase of SA biosynthesis in Arabidopsis.

Our aim in this paper is to study variants and computational errors of the extragradient method for solving equilibrium problems. First, we consider convergence of the method when domains in the auxiliary subproblems of the extragradient algorithm are replaced by outer and inner approximation polyhedra. Then, computational errors are showed under the asymptotic optimality condition, but the bifunction must satisfy certain Lipschitz-type continuous conditions. Next, by using Armijo-type linesearch techniques commonly used in variational inequalities, we obtain an approximation linesearch algorithm without Lipschitz continuity. Convergence analysis of the algorithms is considered under mild conditions on the iterative parameters.

This paper develops a two-step extragradient-viscosity method for finding a common solution to a variational inequality problem and a fixed point problem in a Hilbert space. Combining the two-step extragradient algorithm and the viscosity one, we propose a strongly convergent method, which contains as special cases some existing algorithms. Several numerical experiments are implemented to demonstrate the performance of the proposed method in comparison with classical hybrid extragradient-like algorithms.

We introduce a vertical coupling concept to Fano resonance based terahertz (THz) metamaterials, in order to enhance their modulation characteristics. The approach is demonstrated for an asymmetric split-ring structure fabricated from gold with standard micromachining processes on a fused silica substrate. The realized samples are characterized with THz time-domain spectroscopy and the results are in close agreement with the simulation model. Due to the enhanced field concentration facilitated by vertical coupling, we achieve a 95% modulation depth and 35% resonance frequency tunability at 1.23 THz with less than 1-dB inherent loss. The exemplary device shows vertical coupling as an attractive concept for designing efficient modulators for terahertz imaging applications.

In this paper, building upon subgradient techniques and viscosity-type approximations, we propose a simple projection algorithm for solving the lexicographic Ky Fan inequality in a real Hilbert space, where the lower level is a variational inequality problem. By choosing suitable regularization parameters, a strong convergence of the proposed algorithm is established under mild assumptions imposed on the cost function. Some simple numerical examples are given to illustrate the performance of the proposed algorithm.

Based on the subgradient methods and fixed point techniques, we develop a new iteration method for solving variational inequalities on the solution set of Ky Fan inequalities. The convergence for the proposed algorithms to the solution is guaranteed under certain assumptions in the Euclidean space Rn $\mathcal R^{n}$.

In this paper, by combining the hyperplane projection technique and gradient projection method with Polyak’s stepsizes, we propose a novel projection algorithm to solve the split feasibility problem in Hilbert spaces. Unlike the existing projection methods, our method is designed such that the next iterate is closer to the solution set than the previous one. The weak and strong convergence of new algorithms under standard assumptions are established. We examine the performance of our method on the sparse signal recovery problem. The reported numerical results demonstrate the efficiency of the proposed method.

In this paper, we investigate a bilevel split variational inequality problem (BSVIP) involving a strongly monotone mapping in the upper-level problem and pseudomonotone mappings in the lower-level one. A strongly convergent algorithm for such a BSVIP is proposed and analyzed. In particular, a problem of finding the minimum-norm solution of a split pseudomonotone variational inequality problem is also studied. As a consequence, we get a strongly convergent algorithm for finding the minimum-norm solution to the split feasibility problem, which requires only two projections at each iteration step. An application to discrete optimal control problems is considered.

In this paper, we present new projection methods for solving multivalued variational inequalities on a given nonlinear convex feasible domain. The first one is an extension of the extragradient method to multivalued variational inequalities under the asymptotic optimality condition, but it must satisfy certain Lipschitz continuity conditions. To avoid this requirement, we propose linesearch procedures commonly used in variational inequalities to obtain an approximation linesearch method for solving multivalued variational inequalities. Next, basing on a family of nonempty closed convex subsets of Rn $\mathcal R^{n}$and linesearch techniques, we give inner approximation projection algorithms for solving multivalued variational inequalities and the convergence of the algorithms is established under few assumptions.

SERVPERF (Service Performance) tool needs to be adapted to the context and the usage purpose. Our study aimed to validate the context adapted SERVPERF tool in an Oncology public hospital in Vietnam. A study was conducted in 2020 with 227 in-patients as respondents the modified SERVPERF tool. Data collected were analyzed for tool assessment (reliability and validity). The new order in 5 factors in the modified tool were: (1) Responsiveness; (2) Empathy; (3) Reliability; (4) Tangible and (5) Assurance. The modified tool has a high Cronbach’s alpha of .94. The tool validity was confirmed by Confirmatory Factor Analysis (CFA) where the healthcare service quality item corresponds as χ2/df = 3.79, Comparative Fit Index (CFI) = 0.85, Tucker Lewis Index (TLI) = 0.83, and Root Mean Squared Error of Approximation (RMSEA) = 0.08 are good fit indices. The modified tool SERVPERF with high reliability and validity could be applied for measuring the clients’ perceptions about healthcare service quality in other Oncology public hospitals in Vietnam.

Ratification of the Trans-Pacific Partnership (TPP) will attract a large number of foreign drug companies in the coming years to Vietnam. It is anticipated to bring investment to Vietnam's pharmaceutical industries, lead to increased infrastructure and enable the use of more sophisticated technologies for the discovery, development and manufacture of drugs. However, with respect to pharmaceutical companies, which are producing generic drugs primarily, the availability of biologic will be reduced. Thus, the consequence is, an increase in drug cost resulting in difficulties for patients wishing to procure these drugs. This will be particularly detrimental for developing countries, such as Vietnam and Malaysia.

Ratification of the Trans-Pacific Partnership (TPP) will attract a large number of foreign drug companies in the coming years to Vietnam. It is anticipated to bring investment to Vietnam's pharmaceutical industries, lead to increased infrastructure and enable the use of more sophisticated technologies for the discovery, development and manufacture of drugs. However, with respect to pharmaceutical companies, which are producing generic drugs primarily, the availability of biologic will be reduced. Thus, the consequence is, an increase in drug cost resulting in difficulties for patients wishing to procure these drugs. This will be particularly detrimental for developing countries, such as Vietnam and Malaysia.

In this paper, we propose two strongly convergent parallel hybrid iterative methods for finding a common element of the set of fixed points of a family of asymptotically quasi ϕ-nonexpansive mappings, the set of solutions of variational inequalities and the set of solutions of equilibrium problems in uniformly smooth and 2-uniformly convex Banach spaces. A numerical experiment is given to verify the efficiency of the proposed parallel algorithms.

The purpose of this paper is to introduce a new iteration scheme and prove a strong convergence theorem for finding a common element of the fixed point set of a nonexpansive mapping, the solution set of variational inequalities and the solution set of equilibrium problems. Under certain conditions on parameters, we show that the iterative sequences generated by the scheme strongly converge to a common element in a real Hilbert space.