Impact of Agency Costs on Firm Performance: Evidence from Vietnam

An assumption in agency costs theory is that agency costs can exert a negative impact on firm performance. In this study, we examine the impact of agency costs on firm performance of Vietnamese listed companies. Our sample includes 736 companies in Vietnam during the period om 2010 to 2015. We find that agency costs exert a negative impact on firm performance. Our results are robust to alternative econometric models, including an instrumental variables technique and a system generalized method of moment model. In addition, we show that a debt instrument can be a useful tool to reduce the negative impact of agency costs on firm performance

An efficient adaptive fuzzy hierarchical sliding mode control strategy for 6 degrees of freedom overhead crane

The paper proposes a new approach to efficiently control a three-dimensional overhead crane with 6 degrees of freedom (DoF). Most of the works proposing a control law for a gantry crane assume that it has five output variables, including three positions of the trolley, bridge, and pulley and two swing angles of the hoisting cable. In fact, the elasticity of the hoisting cable, which causes oscillation in the cable direction, is not fully incorporated into the model yet. Therefore, our work considers that six under-actuated outputs exist in a crane system. To design an efficient controller for the 6 DoF crane, it first employs the hierarchical sliding mode control approach, which not only guarantees stability but also minimizes the sway and oscillation of the overhead crane when it transports a payload to a desired location. Moreover, the unknown and uncertain parameters of the system caused by its actuator nonlinearity and external disturbances are adaptively estimated and inferred by utilizing the fuzzy inference rule mechanism, which results in efficient operations of the crane in real time. More importantly, stabilization of the crane controlled by the proposed algorithm is theoretically proved by the use of the Lyapunov function. The proposed control approach was implemented in a synthetic environment for the extensive evaluation, where the obtained results demonstrate its effectiveness. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

In vitro bioactivities of Codonopsis javanica root extract from Kon Tum province, Vietnam

Dangshen Codonopsis javanica exhibits invaluable medicinal properties in herbal remedies; however, there has currently not been much specific analysis of the phytochemicals and bioactivities of this plant. The root ethanol extract of C. javanica contains substances such as saponins, phenolic acids, terpenoids, and alkaloids. It displays an antibacterial effect against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus cereus with the IC50 values of 150, 100, 150, and 90 μg/mL, respectively. The antioxidant capacity of the root extract was also observed with an IC50 value of 46.8 ± 6.8 μg/mL. Furthermore, the extract exhibits activity on human cancer cell lines HepG2 (IC50 = 83.6 ± 2.7 μg/mL) and MCF-7 (IC50 = 95.3 ± 2.3 μg/mL). Hence, this study provides the basic data for further research on the bioactivities of natural compounds of Dangshen C. javanica for the first time

Quantifying antimicrobial access and usage for paediatric diarrhoeal disease in an urban community setting in Asia.

OBJECTIVES: Antimicrobial-resistant infections are a major global health issue. Ease of antimicrobial access in developing countries is proposed to be a key driver of the antimicrobial resistance (AMR) epidemic despite a lack of community antimicrobial usage data. METHODS: Using a mixed-methods approach (geospatial mapping, simulated clients, healthcare utilization, longitudinal cohort) we assessed antimicrobial access in the community and quantified antimicrobial usage for childhood diarrhoea in an urban Vietnamese setting. RESULTS: The study area had a pharmacy density of 15.7 pharmacies/km2 (a pharmacy for every 1316 people). Using a simulated client method at pharmacies within the area, we found that 8% (3/37) and 22% (8/37) of outlets sold antimicrobials for paediatric watery and mucoid diarrhoea, respectively. However, despite ease of pharmacy access, the majority of caregivers would choose to take their child to a healthcare facility, with 81% (319/396) and 88% (347/396) of responders selecting a specialized hospital as one of their top three preferences when seeking treatment for watery and mucoid diarrhoea, respectively. We calculated that at least 19% (2688/14427) of diarrhoea episodes in those aged 1 to <5 years would receive an antimicrobial annually; however, antimicrobial usage was almost 10 times greater in hospitals than in the community. CONCLUSIONS: Our data question the impact of community antimicrobial usage on AMR and highlight the need for better education and guidelines for all professionals with the authority to prescribe antimicrobials

Aquilaria yunnanensis S.C. Huang (Thymelaeaceae), A New Record for the Flora of Vietnam

Aquilaria yunnanensis S.C. Huang (Thymelaeaceae), known to be endemic to Yunnan, is recorded for the first time from Dong Son Ky Thuong Nature Reserve, Quang Ninh Province, Vietnam. A taxonomic description and DNA analysis based on our Vietnamese collections are presented, together with information on its distribution, habitat and colour photographs

Safety and efficacy of fluoxetine on functional outcome after acute stroke (AFFINITY): a randomised, double-blind, placebo-controlled trial

Background Trials of fluoxetine for recovery after stroke report conflicting results. The Assessment oF FluoxetINe In sTroke recoverY (AFFINITY) trial aimed to show if daily oral fluoxetine for 6 months after stroke improves functional outcome in an ethnically diverse population. Methods AFFINITY was a randomised, parallel-group, double-blind, placebo-controlled trial done in 43 hospital stroke units in Australia (n=29), New Zealand (four), and Vietnam (ten). Eligible patients were adults (aged ≥18 years) with a clinical diagnosis of acute stroke in the previous 2–15 days, brain imaging consistent with ischaemic or haemorrhagic stroke, and a persisting neurological deficit that produced a modified Rankin Scale (mRS) score of 1 or more. Patients were randomly assigned 1:1 via a web-based system using a minimisation algorithm to once daily, oral fluoxetine 20 mg capsules or matching placebo for 6 months. Patients, carers, investigators, and outcome assessors were masked to the treatment allocation. The primary outcome was functional status, measured by the mRS, at 6 months. The primary analysis was an ordinal logistic regression of the mRS at 6 months, adjusted for minimisation variables. Primary and safety analyses were done according to the patient's treatment allocation. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000774921. Findings Between Jan 11, 2013, and June 30, 2019, 1280 patients were recruited in Australia (n=532), New Zealand (n=42), and Vietnam (n=706), of whom 642 were randomly assigned to fluoxetine and 638 were randomly assigned to placebo. Mean duration of trial treatment was 167 days (SD 48·1). At 6 months, mRS data were available in 624 (97%) patients in the fluoxetine group and 632 (99%) in the placebo group. The distribution of mRS categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio 0·94, 95% CI 0·76–1·15; p=0·53). Compared with patients in the placebo group, patients in the fluoxetine group had more falls (20 [3%] vs seven [1%]; p=0·018), bone fractures (19 [3%] vs six [1%]; p=0·014), and epileptic seizures (ten [2%] vs two [<1%]; p=0·038) at 6 months. Interpretation Oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and epileptic seizures. These results do not support the use of fluoxetine to improve functional outcome after stroke

Several Human Cyclin-Dependent Kinase Inhibitors, Structurally Related to Roscovitine, As New Anti-Malarial Agents

In Africa, malaria kills one child each minute. It is also responsible for about one million deaths worldwide each year. Plasmodium falciparum, is the protozoan responsible for the most lethal form of the disease, with resistance developing against the available anti-malarial drugs. Among newly proposed anti-malaria targets, are the P. falciparum cyclin-dependent kinases (PfCDKs). There are involved in different stages of the protozoan growth and development but share high sequence homology with human cyclin-dependent kinases (CDKs). We previously reported the synthesis of CDKs inhibitors that are structurally-related to (R)-roscovitine, a 2,6,9-trisubstituted purine, and they showed activity against neuronal diseases and cancers. In this report, we describe the synthesis and the characterization of new CDK inhibitors, active in reducing the in vitro growth of P. falciparum (3D7 and 7G8 strains). Six compounds are more potent inhibitors than roscovitine, and three exhibited IC50 values close to 1 µM for both 3D7 and 7G8 strains. Although, such molecules do inhibit P. falciparum growth, they require further studies to improve their selectivity for PfCDKs

Performance Evaluation of Single-Carrier and Orthogonal Frequency Divison Multiplexing-Based Autoencoders in Comparison with Low-Density Parity-Check Encoder

Recently, the growing demands for ultra-high speed applications require more advanced and optimal data transmission techniques. Wireless autoencoders have gained significant attention since they provide global optimization of the transceiver structure. This article explores the application of autoencoders to enhance the performance of wireless communication systems. It provides the performance evaluation of the systems using single-carrier and OFDM-based autoencoders under the conditions of AWGN and fading channels. Then, in terms of the BLER metric, the wireless systems with autoencoders are compared with conventional systems using LDPC coding and quadrature amplitude modulation for various configurations. Simulation results indicate that for high-modulation orders (QAM-64 or QAM-256), communication systems employing autoencoders provide superior performance compared to systems using LDPC channel encoding in regions with a low signal-to-noise (SNR) ratio. Specifically, a gain of 1–2 dB in signal power is obtained for single-carrier autoencoders and 0.3–2 dB is obtained for OFDM-based autoencoders. Therefore, wireless communication systems utilizing autoencoders can be considered as a promising candidate for future wireless communication systems

Tinctoric acid A-B, two new hopan-type triterpenoids from the Vietnamese lichen, <i>Parmotrema tinctorum</i> (Despr. ex Nyl.) hale with α-glucosidase inhibitory activity

Two new hopan-type triterpenoids, namely tinctoric acid A-B (1-2), were isolated from the lichen Parmotrema tinctorum (Despr. ex Nyl.) Hale. Their structures were elucidated by extensive spectroscopic analyses (1D and 2D NMR). The absolute configuration at C-22 of 1 was established through DP4 probability. Compounds 1-2 were evaluated for their inhibitory activity against α-glucosidase and found to be more potent than those of positive control (acarbose, IC50 168 µM) with values IC50 74.7 and 98.2 µM, respectively. Both of these compounds interacted well with enzyme α-glucosidase MAL32 through H-bonds and hydrophobic interaction.</p