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The study provides the forecasts of expected returns based on cross-sectional estimates from the Fama-Macbeth regressions in the United Kingdom. We collected the data of listed firms on the London Stock Exchange on the DataStream from January 1980 to December 2020. We analyze the data sample by employing three cross-sectional models' ten-year rolling estimates of Fama-Macbeth slopes. The empirical findings demonstrate that an investor can derive a composite estimate of the expected return by integrating various company-specific variables in real-time. Model 1 indicates that the expected-return estimates have a predictive slope for future monthly returns of 95.07%, with a standard error of 0.1981. Moreover, model 2 and model 3 report the predictability of returns are 77.57% and 76.94%. In short, our empirical evidence suggests that investors and stakeholders may consider using model 1 to estimate the cost of equity due to its simplicity and effective prediction capability. Our findings are consistent with trade-off theory and prior literature.

Abstract Background COVID-19 vaccine effectiveness declines months after vaccination. Therefore, it is likely that during the next few years, people may be repeatedly offered a booster vaccine to enhance humoral immunity levels. A growing number of people are questioning whether the benefits of a booster vaccine outweigh the side-effects. Objective This study aims (1) to identify the most frequently reported side-effects after different doses of COVID-19 mRNA vaccines, (2) and the longest lasting symptoms; and (3) to predict the likelihood of having moderate-to-severe side-effects after a booster COVID-19 mRNA vaccine given individual- and vaccine-specific characteristics. Design, setting, and participants Secondary analysis of a prospective cohort study in primary health care providers (PHCPs) in Belgium conducted between December 2020 and December 2021, and in February-March 2023. Methods In nine subsequent surveys over a period of 2 years vaccine dose-number and side-effects after COVID-19 vaccines were collected. A Generalized Estimation Equations approach on the data of the first and second booster dose was used to investigate the probability of having moderate-to-severe side-effects after mRNA booster vaccination. Predictive performance of a binary classifier was assessed by looking at discrimination (i.e., quantified in terms of the area under the receiver operating characteristic curve). The final prediction model was validated using data with regard to the third booster by assessing misclassification rate, sensitivity and specificity. Results In total, 11% of the PHCPs had moderate-to-severe side-effects after their booster COVID-19 mRNA vaccine. The most common side-effects of COVID-19 mRNA doses included fatigue, local pain at the injection site, general pains, and headache. These side-effects typically lasted for a median of 1 to 2 days. The final model included five predictors: sex, alcohol consumption, history of moderate-to-severe side-effects after any previous dose, recent COVID-19 infection, and the booster dose-number (first, second). Having experienced moderate-to-severe side-effects after any previous dose was the strongest predictor of moderate-to-severe side-effects following an mRNA vaccine booster, with an odds ratio (OR) of 3.64 (95% CI: 2.80–4.75). The OR for female sex was 1.49 (95% CI: 1.21–1.84) implying that females have a higher odds of moderate-to-severe side-effects following booster vaccination. The differences in effect for booster dose-number, alcohol consumption and recent COVID-19 infection was not significant. Conclusion and relevance COVID-19 mRNA booster vaccination implies a low prevalence of moderate-to-severe side-effects among PHCPs, with a short median duration of symptoms if any. The strongest predictors are a history of moderate-to-severe side-effects after any previous dose and being female. These reassuring findings can help addressing concerns about booster vaccination and encourage their uptake. Trial Registration NCT04779424 (registration date: 2021-02-22).

Abstract Previous studies have reported the functional role, biochemical features and synthesis pathway of podophyllotoxin (PTOX) in plants. In this study, we employed combined morphological and molecular techniques to identify an endophytic fungus and extract PTOX derivatives. Based on the analysis of ITS sequences and the phylogenetic tree, the isolate was classified as Penicillium herquei HGN12.1C, with a sequence identity of 98.58%. Morphologically, the HGN12.1C strain exhibits white colonies, short‐branched mycelia and densely packed hyphae. Using PacBio sequencing at an average read depth of 195×, we obtained a high‐quality genome for the HGN12.1C strain, which is 34.9 Mb in size, containing eight chromosomes, one mitochondrial genome and a GC content of 46.5%. Genome analysis revealed 10 genes potentially involved in PTOX biosynthesis. These genes include VdtD, Pinoresinollariciresinol reductase (PLR), Secoisolariciresinol dehydrogenase (SDH), CYP719A23, CYP71BE54, O‐methyltransferase 1 (OMT1), O‐methyltransferase 3 (OMT3), 2‐ODD, CYP71CU and CYP82D61. Notably, the VdtD gene in fungi shares functional similarities with the DIR gene found in plants. Additionally, we identified peltatin, a PTOX derivative, in the HGN12.1C extract. Docking analysis suggests a potential role for the 2‐ODD enzyme in converting yatein to deoxypodophyllotoxin. These findings offer invaluable insights into the synthesis mechanism of PTOX in fungi, shedding light on the relationship between host plants and endophytes.

Background: Viremia is a critical factor in understanding the pathogenesis of dengue infection, but limited data exist on viremia kinetics. This study aimed to investigate the kinetics of viremia and its effects on subsequent platelet count, severe dengue, and plasma leakage. Methods: We pooled data from three studies conducted in Vietnam between 2000 and 2016, involving 2340 dengue patients with daily viremia measurements and platelet counts after symptom onset. Viremia kinetics were assessed using a random effects model that accounted for left-censored data. The effects of viremia on subsequent platelet count and clinical outcomes were examined using a landmark approach with a random effects model and logistic regression model with generalized estimating equations, respectively. The rate of viremia decline was derived from the model of viremia kinetics. Its effect on the clinical outcomes was assessed by logistic regression models. Results: Viremia levels rapidly decreased following symptom onset, with variations observed depending on the infecting serotype. DENV-1 exhibited the highest mean viremia levels during the first 5–6 days, while DENV-4 demonstrated the shortest clearance time. Higher viremia levels were associated with decreased subsequent platelet counts from day 6 onwards. Elevated viremia levels on each illness day increased the risk of developing severe dengue and plasma leakage. However, the effect size decreased with later illness days. A more rapid decline in viremia is associated with a reduced risk of the clinical outcomes. Conclusions: This study provides comprehensive insights into viremia kinetics and its effect on subsequent platelet count and clinical outcomes in dengue patients. Our findings underscore the importance of measuring viremia levels during the early febrile phase for dengue studies and support the use of viremia kinetics as outcome for phase-2 dengue therapeutic trials. Funding: Wellcome Trust and European Union Seventh Framework Programme.

An image-quality CT phantom was scanned with three different 3D X-ray imaging guidance devices in the operating theatre: O-Arm, Loop-X, and Airo TruCT. Default acquisition and reconstruction parameters for lumbar spine procedures were used on each device. The tube current was set to a dose level of around 27 mGy. A task-based image quality assessment was performed by calculating the noise power spectrum (NPS) and task transfer function (TTF). A detectability index (d’) was calculated for three simulated bone lesions. The noise magnitude of the O-Arm was higher than the Airo TruCT, and the Loop-X had higher noise than the Airo TruCT. The highest average NPS frequency was for the O-Arm images, and the lowest was for the Loop-X. The TTFs at 50% values were similar for the Airo TruCT and Loop-X devices. Compared to Airo TruCT, the TTF at 50% value increased with the O-Arm by 53.12% and 41.20% for the Teflon and Delrin inserts, respectively. Compared to Airo TruCT, the d’ value was lower with Loop-X by −26.73%, −27.02%, and −23.95% for lytic lesions, sclerotic lesions, and high-density bone, respectively. Each 3D-imaging spine surgery guidance device has its own strengths and weaknesses in terms of image quality. Cone-beam CT systems apparently offer the best compromise between noise and spatial resolution for spine surgery.

Background: Benzodiazepines and Z-drugs (BZD/Z) are frequently prescribed for longer than recommended. Through their interactions with patients taking BZD/Z, primary care and mental health professionals play a key role in the management of this medication. Aim: To explore how primary care and mental health care professionals set treatment goals with users of long-term BZD/Z. Design & setting: A qualitative study using semi-structured interviews with professionals from mental health, addiction care, and primary care practices in Belgium. Method: Semi-structured interviews were conducted, online and in person, with 24 professionals working in mental health and primary care. Inductive thematic content analysis was performed. Results: Seven themes were identified from the analysis. Professionals tended not to use the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V) standard to diagnose a BZD/Z substance use disorder. They described criteria based on their experience. They identified diverse types of patients that influence their choice of treatment goals. Professionals appeared to position themselves according to their own treatment goals for their patients, either by promoting the goal of abstinence or harm reduction. Some of them reported feeling trapped into continuing to prescribe and considered BZD/Z withdrawal to be difficult. Some were afraid to engage in a conversation that might break the bond of trust with the patient. Few professionals mentioned patient participation in the treatment goal setting. They asked for targeted withdrawal recommendations, perceiving the current recommendations to be too broad. Conclusion: Whether primary care or mental health care professionals are more in favour of a total abstinence or a harm reduction approach to BZD/Z, professionals should be guided towards greater patient participation in setting and evaluating goals with patients taking BZD/Z.

Research into nanomaterials yields numerous exceptional applications in contemporary science and technology. The subject of this investigation is a one-dimensional nanostructure, six atoms wide, featuring hydrogen-functionalized edges. The theoretical foundation of this study relies on Density Functional Theory (DFT) and is executed through the utilization of the Vienna Ab initio Simulation Package (VASP). The outcomes demonstrate the stability of adsorption configurations, along with the preservation of a hexagonal honeycomb lattice. The pristine configuration, characterized by a wide bandgap, is well-suited for optoelectronic applications, whereas adsorption configurations find their application in gas sensing. Nitrogen (N) adsorption transforms the semiconducting system into a semimetallic one, with the spin-up state showing semiconductor characteristics and the spin-down state exhibiting metallic attributes. The intricate multi-orbital hybridization is explored through the analysis of partial states. While the pristine system remains non-magnetic, N adsorption introduces a magnetic moment of 0.588 μB. The examination of charge density differences indicates a significant charge transfer from N to the CGe substrate surface. Optical properties are systematically investigated, encompassing the dielectric function, absorption coefficient and electron–hole density. Notably, the real part of the dielectric function exhibits negative values, a result that holds promise for future communication applications.

This study aimed to evaluate the impact of three two-dimensional (2D) mammographic acquisition techniques on image quality and radiation dose in the presence of silicone breast implants (BIs). Then, we propose and validate a new International Atomic Energy Agency (IAEA) phantom to reproduce these techniques. Images were acquired on a single Hologic Selenia Dimensions® unit. The mammography of the left breast of a single clinical case was included. Three methods of image acquisition were identified. They were based on misused, recommended, and reference settings. In the clinical case, image criteria scoring and the signal-to-noise ratio on breast tissue (SNRBT) were determined for two 2D projections and compared between the three techniques. The phantom study first compared the reference and misused settings by varying the AEC sensor position and, second, the recommended settings with a reduced current-time product (mAs) setting that was 13% lower. The signal-difference-to-noise ratio (SDNR) and detectability indexes at 0.1 mm (d’ 0.1 mm) and 0.25 mm (d’ 0.25 mm) were automatically quantified using ATIA software. Average glandular dose (AGD) values were collected for each acquisition. A statistical analysis was performed using Kruskal–Wallis and corrected Dunn tests (p < 0.05). The SNRBT was 2.6 times lower and the AGD was −18% lower with the reference settings compared to the recommended settings. The SNRBT values increased by +98% with the misused compared to the recommended settings. The AGD increased by +79% with the misused settings versus the recommended settings. The median values of the reference settings were 5.8 (IQR 5.7–5.9), 1.2 (IQR 0.0), 7.0 (IQR 6.8–7.2) and 1.2 (IQR 0.0) mGy and were significantly lower than those of the misused settings (p < 0.03): 7.9 (IQR 6.1–9.7), 1.6 (IQR 1.3–1.9), 9.2 (IQR 7.5–10.9) and 2.2 (IQR 1.4–3.0) mGy for the SDNR, d’ 0.1 mm, d’ 0.25 mm and the AGD, respectively. A comparison of the recommended and reduced settings showed a reduction of −6.1 ± 0.6% (p = 0.83), −7.7 ± 0.0% (p = 0.18), −6.4 ± 0.6% (p = 0.19) and −13.3 ± 1.1% (p = 0.53) for the SDNR, d’ 0.1 mm, d’ 0.25 mm and the AGD, respectively. This study showed that the IAEA phantom could be used to reproduce the three techniques for acquiring 2D mammography images in the presence of breast implants for raising awareness and for educational purposes. It could also be used to evaluate and optimize the manufacturer’s recommended settings.

When COVID-19 vaccines were implemented, nursing home residents (NHRs) and staff (NHS) in Belgium were prioritized for vaccination. To characterize the vaccine response over time in this population and to identify poorly responding groups, we assessed antibody concentrations two (T1), four (T2) and six months (T3) after primary course BNT162b2 vaccination in six groups of infection-naive/infection-primed NHRs/NHS, with/without comorbidity (NHRs only). Participant groups (N = 125 per group) were defined within a national serosurveillance study in nursing homes, based on questionnaire data. Dried blood spots were analyzed using ELISA for the quantification of SARS-CoV-2 S1RBD IgG antibodies. Among all groups, antibody concentrations significantly decreased between T1 and T2/T3, all with a ≥70% decrease at T3, except for infection-primed staff (−32%). Antibody concentrations among infection-naive NHRs were 11.96 times lower than those among infection-primed NHR, while the latter were comparable (x1.05) to infection-primed NHS. The largest proportion [13% (95% CI: 11–24%)] of vaccine non-responders was observed in the group of infection-naive NHRs with comorbidities. A longer interval between infection and vaccination (≥3 months) elicited higher antibody responses. Our data retrospectively show the necessity of timely COVID-19 booster vaccination. Infection-naive NHRs require special attention regarding immune monitoring in future epidemics or pandemics.

New COVID-19 strains and waning vaccine effectiveness prompted initiatives for booster vaccination. In Belgium, healthcare providers (HCPs) received a second booster in July 2022, with eligible individuals receiving a third in autumn. Primary HCPs (PHCPs) play a crucial role in healthcare organization and patient communication. This study, conducted in February–March 2023, surveyed 1900 Belgian PHCPs to assess their views on periodic COVID-19 boosters for themselves and their patients. The survey included questions on sociodemographic information, willingness to receive periodic COVID-19 boosters, reasons for acceptance or refusal, confidence in vaccine safety and efficacy, and views on booster recommendations. Overall, 86% of participants were willing to receive periodic COVID-19 boosters, motivated by self-protection, patient well-being, and the uninterrupted delivery of healthcare services. Factors influencing booster refusal included not being a general practitioner (GP) or GP trainee, working in Wallonia or Brussels, and lacking vaccine confidence. Although 243 participants would not take boosters periodically, only 74 would not recommend it. Regarding administration, 59% supported pharmacist involvement in COVID-19 vaccination. Further qualitative analysis of 290 PHCPs’ responses revealed varying recommendations, including specific roles like nurses, organizational structures, and collaborative approaches. This study highlights the need to address vaccine confidence, regional disparities, and PHCP roles in booster implementation.

In Belgium, nursing home (NH) staff (NHS) and residents were prioritised for the initial COVID-19 vaccination and successive booster doses. The vaccination campaign for the first booster started in September 2021 in Belgian NH. Our first study about vaccine hesitancy towards the COVID-19 vaccine in Belgian NHS already showed a degree of fear for the primary vaccination course (T1). This new study aims to evaluate vaccine hesitancy to get the first booster (T2) in a population of fully vaccinated (with two doses) NHS. A random stratified sample of NHS who received the primary vaccination course (N = 954) completed an online questionnaire on COVID-19 booster hesitancy (between 25/11/2021 and 22/01/2022). NHS who hesitated or refused the booster were asked for the main reason for their hesitation/refusal. Overall, 21.0 % of our population hesitated before, were still hesitating or refused the booster, NHS that were not hesitant at T1 being 5.7 times less likely to hesitate to get the first booster dose (Adjusted OR 0.179, 95 % CI: 0.120, 0.267). Although there was a slight reduction (23.5 % to 20.1 %) in the proportion of NHS who hesitated/refused vaccination at T1 compared to T2 (p = 0.034), the fear of unknown effects was the principal reason for hesitation/refusal, already mentioned in our first study. NHS were not reassured concerning their initial fears. Given the likelihood that booster vaccinations will be necessary over the coming years, a communication strategy specific to NHS should be implemented.

Camellia sinensis var. madoensis is described and illustrated as a new variety of Camellia sinensis (section Thea, Theaceae) from Xuan Loc Commune, Song Cau District, Phu Yen Province. The new variety is easily distinguishable from C. sinensis var. sinensis by style free ½ to the base. The ITS sequence of this variety is also different from that of Camellia sinensis and its other varieties, while the matK gene sequences are nearly identical among Camellia taxa.

Abstract Perturbations in the gut microbiome have been associated with colorectal cancer (CRC), with the colonic overabundance of Fusobacterium nucleatum shown as the most consistent marker. Despite its significance in the promotion of CRC, genomic studies of Fusobacterium is limited. We enrolled 43 Vietnamese CRC patients and 25 participants with non-cancerous colorectal polyps to study the colonic microbiomes and genomic diversity of Fusobacterium in this population, using a combination of 16S rRNA gene profiling, anaerobic microbiology, and whole genome analysis. Oral bacteria, including F. nucleatum and Leptotrichia, were significantly more abundant in the tumour microbiomes. We obtained 53 Fusobacterium genomes, representing 26 strains, from the saliva, tumour and non-tumour tissues of six CRC patients. Isolates from the gut belonged to diverse F. nucleatum subspecies (nucleatum, animalis, vincentii, polymorphum) and a potential new subspecies of Fusobacterium periodonticum. The Fusobacterium population within each individual was distinct and in some cases diverse, with minimal intra-clonal variation. Phylogenetic analyses showed that within four individuals, tumour-associated Fusobacterium were clonal to those isolated from non-tumour tissues. Genes encoding major virulence factors (Fap2 and RadD) showed evidence of horizontal gene transfer. Our work provides a framework to understand the genomic diversity of Fusobacterium within the CRC patients, which can be exploited for the development of CRC diagnostic and therapeutic options targeting this oncobacterium.

The multi-pixel photon counter (MPPC) has recently emerged as a great type of silicon photomultiplier to replace or compensate for conventional vacuum-based photomultiplier tubes. An MPPC provides many advantageous features, such as high electrical gain, outstanding photon detection efficiency, fast timing response, immunity to magnetic fields, low-voltage operation, compactness, portability, and cost-effectiveness. This article examines the electrical and optical characteristics of an MPPC under loosely controlled environmental conditions. We also report a measurement of the light yield captured by the MPPC when a cosmic ray passes through the plastic scintillator, demonstrating that such a setup is suitable as a simple, cost-effective tabletop cosmic ray detector for educational and research purposes.

Mechanically stabilized earth (MSE) walls have been widely applied in construction to maintain the stability of high embankments. In Vietnam, imported reinforcement materials are expensive; thus, finding locally available materials for MSE walls is beneficial. This study examines the behavior of an MSE wall using local reinforcement materials in Danang, Vietnam. The MSE was reinforced by self-fabricated galvanized steel grids using CB300V steel with 3 cm ribs. The backfill soil was sandy clay soil from the local area with a low cohesion. A full-scale model with full instrumentation was installed to investigate the distribution of tensile forces along the reinforcement layers. The highest load that caused the wall to collapse due to internal instability (reinforcement rupture) was 302 kN/m2, which is 15 times greater than the design load of 20 kN/m2. The failure surface within the reinforced soil had a parabolic sliding shape that was similar to the theoretical studies. At the failure load level, the maximum lateral displacement at the top of the wall facing was small (3.9 mm), significantly lower than the allowable displacement for a retaining wall. Furthermore, a numerical model using FLAC software 7.0 was applied to simulate the performance of the MSE wall. The modeling results were in good agreement with the physical model. Thus, self-fabricated galvanized steel grids could confidently be used in combination with the local backfill soil for MSE walls.

Introduction: Breaking bad news (BBN) in the emergency department (ED) represents a challenging and stressful situation for physicians. Many medical students and residents feel stressed and uncomfortable with such situations because of insufficient training. Our randomized controlled study aimed to assess the efficacy of a four-hour BBN simulation-based training on perceived self-efficacy, the BBN process, and communication skills.Methods: Medical students and residents were randomized into a 160-hour ED clinical rotation without a formal BBN curriculum (control group [CG], n = 31) or a 156-hour ED clinical rotation and a four-hour BBN simulation-based training (training group [TG], n = 37). Both groups were assessed twice: once at the beginning of the rotation (pre-test) and again four weeks later. Assessments included a BBN evaluation via a simulation with two actors playing family members and the completion of a questionnaire on self-efficacy. Two blinded raters assessed the BBN process with the SPIKES (a delivery protocol for delivering bad news) competence form and communication skills with the modified BBN Assessment Schedule.Results: Group-by-time effects adjusted by study year revealed a significant improvement in TG as compared with CG on self-efficacy (P < 0.001), the BBN process (P < 0.001), and communication skills (P < 0.001). TG showed a significant gain regarding the BBN process (+33.3%, P < 0.001). After the training, students with limited clinical experience prior to the rotation showed BBN performance skills equal to that of students in the CG who had greater clinical experience.Conclusion: A short BBN simulation-based training can be added to standard clinical rotations. It has the potential to significantly improve self-efficacy, the BBN process, and communication skills.

ABSTRACT: Left ventricular diverticulum is a rare congenital left ventricular outpouchings. The disease is often diagnosed during childhood because it is frequently associated with midline thoracoabdominal defects and other congenital cardiac anomalies. Most cases are asymptomatic, often discovered incidentally. Some complications have been reported including infarction, arrhythmia, heart failure. The most severe complication is rupture of the diverticulum, which can cause a patient's death. Therefore, this congenital defect should be detected early to assess potential risks for appropriate treatment. In this article, we report a case of a 3-month-old boy with left ventricular diverticulum diagnosed with Doppler ultrasound and cardiac MSCT. Complete resection was undertaken. The patient remained asymptomatic with good heart function 2 months after surgery.

A new species, Quercus sontraensis Ngoc, Binh & Son is described from Son Tra Nature Reserve, Son Tra Peninsula, Central Vietnam. We examined the morphology and constructed a highly resolved phylogeny of Q. sontraensis and its relatives (including Q. langbianensis and Q. cambodiensis) using Multiplex ISSR genotyping by sequencing (MIG-seq). The morphological analyses and molecular evidence support the distinction between the new species (Q. sontraensis) and its relatives.

Pigmented villonodular synovitis is a rare proliferative process, especially in children. Pigmented villonodular synovitis can affect the synovial joint, tendon sheaths, and bursa membranes. Within synovial joint involvement, it is commonly seen in the knee joint but hip, ankle, shoulder, wrist, and other joints can be involved. The appearance characteristic is found on a magnetic resonance imaging scan. Complete excision and synovectomy are the usual treatment. In this article, we report a case of pigmented villonodular synovitis of the knee in a 12- year-old girl who underwent total synovectomy after the diagnosis was confirmed by biopsy. Three years after surgery, neither recurrence nor joint degeneration was found. The osteochondral defect at the tibial plateau was filled with calcium phosphate bone paste.

Three new species, Lithocarpus bidoupensis Ngoc & Tagane, L. congtroiensis Ngoc & Yahara, and L. hongiaoensis Ngoc & Binh are described from Bidoup-Nui Ba National Park, Central Highland of Vietnam. Morphological analyses and Maximum likelihood tree based on genome-wide SNPs support the distinction of those species from the previously known taxa in the region. The three new species are considered to be endemic to the Bidoup-Nui Ba National Park and the preliminary conservation status for each species is evaluated as Critically Endangered.

In this paper, we introduce the λ-quadratic functional equation with three variables and obtain its general solution. The main aim of this work is to examine the Ulam-Hyers stability of this functional equation in non-Archimedean Banach space by using direct and fixed point techniques and examine the stability results in non-Archimedean random normed space.

University educational system plays an important role for the development of any country. Most industries normally rely on highly educated people with different skills and the universities are also responsible for training leading edge technology skills. During the past few years, there have been tremendous efforts to empower Vietnamese universities and to put more efforts to increase their ranking internationally. The purpose of this study is to determine the appropriate leadership style on higher education institutions and the role of the leader in promoting academic research at Vietnamese universities. Excellent and effective leadership is needed to develop employees as a sustainable competitive advantage. The leaders of organizations normally have difficulty in speeding up the performance of their followers. Individual performance is studied and evaluated in both scholarly and practical literature. Employee engagement is not only a moderator concept established in organizational theory, but it also offers a variety of views and theories. This paper designs a questionnaire and distributes it among 232 students to measure the effect of transformational leadership in higher educational organizations. Regression analysis is used to measure the effects of different components of transformational leadership on the performance of organizations. The survey results indicate that the Transformational leadership could actually be effective when they are allowed autonomy in organizations, especially on the budget. In summary, the results of the investigation clarify the role and importance of transformational leadership in organizations.

BackgroundThe mid-life emergence of higher levels of total cholesterol (TC) for women than for men has been observed in different Western and Asian populations. The aim of this study was to investigate whether there is evidence of this in Vietnam and, if so, whether it can be explained by ageing, by body size and fatness, or by socio-demographic characteristics and behavioural factors.MethodsParticipants (n = 14706, 50.9% females) aged 25-64 years were selected by multi-stage stratified cluster sampling from eight provinces each representing one of the eight geographical regions of Vietnam. Measurements were made using the World Health Organization STEPS protocols. Linear regression was used to assess the independent contributions of potential explanatory factors to mean levels of TC. Data were analysed using complex survey methods.ResultsMen and women had similar mean levels of body mass index (BMI), and men had modestly higher mean levels of waist circumference (WC), in each 5-year age category. The mean TC of women increased more or less continuously across the age range but with a step-up at age 50 years to reach higher concentrations on average than those of their male counterparts. The estimated step-up was not eliminated by adjustment for anthropometric indices including BMI or WC, or by adjustment for socio-demographic characteristics or behavioural factors. The estimated step-up was least for women with the greatest weight.ConclusionThere is a marked step-up in TC at age 50 years for Vietnamese women that cannot be explained by their age, or by their body fatness or its distribution, or by their socio-demographic characteristics or behavioural factors, and which results in greater mean levels of TC for middle-aged women than for their male counterparts in Vietnam.

In Belgium, nursing home staff (NHS) and residents were prioritised for COVID-19 vaccination. However, vaccine hesitancy may have impacted vaccination rates. In this study, a random stratified sample of NHS (N = 1142), vaccinated and unvaccinated, completed an online questionnaire on COVID-19 vaccine hesitancy (between 31 July and 15 November 2021). NHS who hesitated or refused the vaccine were asked for the main reason for their hesitation/refusal. Those who hesitated, but eventually accepted vaccination, were asked why they changed their minds. Overall, 29.5% of all respondents hesitated before accepting vaccination, were still hesitating, or refused vaccination. Principal reasons were fear of unknown future effects (55.1% of vaccinated participants that hesitated and 19.5% who refused), fear of side-effects (12.7% of vaccinated participants that hesitated and 12.2% who refused), and mistrust in vaccination (10.5% of vaccinated participants that hesitated and 12.2% who refused). For vaccinated participants who hesitated initially, protecting the vulnerable was the main reason they changed their minds. Given this degree of fear and proposals to mandate vaccination among healthcare workers, communicating with NHS on the safety and efficacy of the vaccine should be prioritised.

We demonstrated a multi-band plasmonic metamaterial absorber (MA), based on the near-field coupled resonators. In addition to the individual resonances of resonators in the proposed structure, which were split-ring resonator (SRR) and cross-shape structures, another resonance was also excited owing to the coupling of resonators, revealing a triple-band absorption. Furthermore, to control the absorption behavior, on the top of the SRRs, the identical SRRs made of graphene ink were pasted. By increasing the resistance of graphene ink, the coupling strength was weakened, changing the triple-band absorption to a dual-band one. Our work might be useful as the controllable devices, based on graphene-integrated plasmonic MA, such as filters, detectors and energy harvesters.

Abstract Background Dengue virus infection results in a broad spectrum of clinical outcomes, ranging from asymptomatic infection through to severe dengue. Although prior infection with another viral serotype, i.e. secondary dengue, is known to be an important factor influencing disease severity, current methods to determine primary versus secondary immune status during the acute illness do not consider the rapidly evolving immune response, and their accuracy has rarely been evaluated against an independent gold standard. Methods Two hundred and ninety-three confirmed dengue patients were classified as experiencing primary, secondary or indeterminate infections using plaque reduction neutralisation tests performed 6 months after resolution of the acute illness. We developed and validated regression models to differentiate primary from secondary dengue on multiple acute illness days, using Panbio Indirect IgG and in-house capture IgG and IgM ELISA measurements performed on over 1000 serial samples obtained during acute illness. Results Cut-offs derived for the various parameters demonstrated progressive change (positively or negatively) by day of illness. Using these time varying cut-offs it was possible to determine whether an infection was primary or secondary on single specimens, with acceptable performance. The model using Panbio Indirect IgG responses and including an interaction with illness day showed the best performance throughout, although with some decline in performance later in infection. Models based on in-house capture IgG levels, and the IgM/IgG ratio, also performed well, though conversely performance improved later in infection. Conclusions For all assays, the best fitting models estimated a different cut-off value for different days of illness, confirming how rapidly the immune response changes during acute dengue. The optimal choice of assay will vary depending on circumstance. Although the Panbio Indirect IgG model performs best early on, the IgM/IgG capture ratio may be preferred later in the illness course.

The taxonomy of Quercus langbianensis and its relatives in Vietnam and Cambodia have been revised based on evidence obtained from field observations, morphological comparison of herbarium specimens and molecular analyses using both classic and next generation DNA markers. Based on Bayesian inference using rbcL, matK and ITS regions and Neighbour-joining tree using genome-wide sequences amplified with multiplexed inter-simple sequence repeat (ISSR) primers (MIG-seq), the authors recognised ten species in the complex in Vietnam and Cambodia, three of which are newly described in this paper: Q. baolamensis sp. nov., Q. bidoupensis sp. nov. and Q. honbaensis sp. nov. These new species are all phenotypically similar to Q. langbianensis s. str. in having lanceolate to oblanceolate leaf shape, upper 4–5/6–serrated leaf margin, acute or acuminate leaf apex and bracts of cupule arranged in 5–9 rings but distinguished both morphologically and phylogenetically. In molecular phylogenetic reconstructions, Q. bidoupensis is not close to any other species. In the Bayesian tree, Q. honbaensis is sister to both Q. blaoensis and Q. camusiae that are found in the same locality but morphologically distinct and those three species are sister to Q. langbianensis s. str., while Quercus baolamensis is not sister to Q. langbianensis s. str. in both the Bayesian tree and MIG-seq tree. In addition, Q. cambodiensis and Q. baniensis previously reduced to Q. langbianensis s. lat. have been recognised as distinct species. Six species were in need of lectotypification and that is undertaken herein.

A new species, Quercus xuanlienensis Binh, Ngoc & Bon, is described from Xuan Lien Nature Reserve, Vietnam. The new species is morphologically similar to Q. edithiae Skan, in having 8–11 pairs of secondary veins, bowl-shaped cupules and ellipsoid to cylindrical-ellipsoid and basally convex nuts. It differs in having serrulate leaf margins only at apical 1/5–1/7, almost entire margins of bracts on cupule and much longer nuts. The species is also similar to Q. fleuryi Hickel & A. Camus in having leaves glabrous on both surfaces with only an apically serrulate margin but differs in having shorter petioles, cupules enclosing 1/5 of the nut and much longer nuts. In addition, Q. disciformis Chun & Tsiang. and Q. bella Chun & Tsiang., previously known from China, are newly recorded from Ba Vi National Park, Vietnam.

The study aims to develop a reliable model using gene-expression programming (GEP) technique for estimating the unconfined compressive strength (UCS) of soil stabilization by cement and fly ash. The model considered the effects of several parameters, including the fly ash characteristics such as calcium oxide (CaO) content, CaO/SiO2 ratio, and loss of ignition. The research results show that the proposed model demonstrates superior performance with a high correlation coefficient (R > 0.955) and low errors. Therefore, the model could be confidently applied in practice for a variety of fly ash qualities. Besides, the parametric study was conducted to examine the effect of fly ash characteristics on the strength of soil stabilization. The study indicates that if the fly ash contains a high amount of calcium oxide, the strength of fly ash stabilized soil is significant. In addition, fly ash could be used in combination with cement to increase the strength of the mixture. A fly ash replacement ratio is suggested from 0.19 to 0.35, corresponding to the total binder used from 10% to 30%. The research findings could help engineers in optimizing the fly ash proportion and estimating the UCS of soil stabilization by cement and fly ash.

Abstract High-quality large-area graphene/h-BN vertical heterostructures are promising building blocks for many viable applications such as energy harvesting/conversion, electronics and optoelectronics. Here, we successfully grew high-quality large-area graphene/h-BN vertical heterostructures on Pt foils by one-batch low-pressure chemical vapor deposition (LPCVD). We obtained the high quality of about 200-µm-wide graphene/h-BN film having uniform layer thickness. Moreover, the obtained graphene/h-BN heterostructures exhibited field effect mobility of up to 7,200 cm2V−1s−1 at room temperature. These results suggest that such graphene/h-BN heterostructures on recyclable Pt foils grown by LPCVD are promising for high-performance graphene-based electronics.

Macrosolen bidoupensis Tagane & V.S.Dang, sp. nov. (Loranthaceae) is newly described from Bidoup Nui Ba National Park in Lam Dong Province, southern Vietnam. The new species is characterized by small broadly elliptic to circular leaves, sessile to short petioles, slightly cordate to rounded leaf bases, 4–5 pairs of lateral veins and a basally green corolla tube. An illustration, a summary of DNA barcoding of the plastid genes rbcL and matK, and a key to the species of Macrosolen in Vietnam are provided.

Introduction: Breaking bad news (BBN) in the emergency department (ED) represents a challenging and stressful situation for physicians. Many medical students and residents feel stressed and uncomfortable with such situations because of insufficient training. Our randomized controlled study aimed to assess the efficacy of a four-hour BBN simulation-based training on perceived self-efficacy, the BBN process, and communication skills. Methods: Medical students and residents were randomized into a 160-hour ED clinical rotation without a formal BBN curriculum (control group [CG], n = 31) or a 156-hour ED clinical rotation and a four-hour BBN simulation-based training (training group [TG], n = 37). Both groups were assessed twice: once at the beginning of the rotation (pre-test) and again four weeks later. Assessments included a BBN evaluation via a simulation with two actors playing family members and the completion of a questionnaire on self-efficacy. Two blinded raters assessed the BBN process with the SPIKES (a delivery protocol for delivering bad news) competence form and communication skills with the modified BBN Assessment Schedule. Results: Group-by-time effects adjusted by study year revealed a significant improvement in TG as compared with CG on self-efficacy (P < 0.001), the BBN process (P < 0.001), and communication skills (P < 0.001). TG showed a significant gain regarding the BBN process (+33.3%, P < 0.001). After the training, students with limited clinical experience prior to the rotation showed BBN performance skills equal to that of students in the CG who had greater clinical experience. Conclusion: A short BBN simulation-based training can be added to standard clinical rotations. It has the potential to significantly improve self-efficacy, the BBN process, and communication skills.

Dysphagia is the most common symptom in symptomatic patients with aberrant right subclavian artery (ARSA) and also the risk factor of aspiration, especially in elderly patients. We presented an 84 year-old female patient with dysphagia induced by the compression of ARSA to the adjacent structures. Recurrent pneumonia and bibasilar bronchiectasis were recorded in the association with ARSA. We concluded that elderly patient with ARSA should be evaluated the pulmonary complications such as aspiration pneumonia and bronchiectasis. Keywords: Aberrant right subclaviann artery, Arteria lusoria, Bronchiectasis, Chronic aspiration