Search Results (51)

This study combines the “flow theory” and the “extended technology acceptance model” (ETAM) to explore the perceived utility and sustainable development impact of virtual reality (VR) immersive learning in the hairdressing course of vocational schools. The research subjects were 1200 students from three vocational schools in Chiayi and Tainan, Taiwan. Data analysis was performed using SPSS 22.0 and Smart PLS 3. The main findings are as follows: (1) Model validation shows that vocational school students’ acceptance of VR learning is significantly affected by perceived usefulness (PU) and perceived ease of use (PE), and both positively affect attitude towards use (ATU). (2) Flow theory (FLOW) not only directly improves students’ usage attitude and behavioral intention (BI), but also partially mediates the relationship between PU/PE and ATU, indicating that immersion is the core factor driving learning motivation. (3) VR technology reduces the consumption of physical resources (such as wig models), meets the United Nations SDG 4 (quality education), SDG 9 (industrial innovation), and SDG 12 (responsible consumption) goals, and is cost-effective. (4) Students’ feedback pointed out that VR teaching stimulates creativity and independent learning, but it needs to be combined with traditional demonstration teaching to strengthen technical details. Full article

Investing in the stock market has always been an exciting topic for people. Many specialists have tried to develop tools to predict future stock prices in order to make high profits and avoid big losses. However, predicting prices based on the dynamic characteristics of stocks seems to be a non-trivial problem. In practice, the predictive models are not expected to provide the most accurate forecasts of stock prices, but to highlight changes and discrepancies between the predicted and observed values, to warn against threats, and to inform users about upcoming opportunities. In this paper, we discuss the use of frequent sequences as well as association rules in WIG20 stock price prediction. Specifically, our study used two methods to approach the problem: correlation analysis based on the Pearson correlation coefficient and frequent sequence mining with temporal constraints. In total, 43 association rules were discovered, characterized by relatively high confidence and lift. Moreover, the most effective rules were those that described the same type of trend for both companies, i.e., rise ⇒ rise, or fall ⇒ fall. However, rules that showed the opposite trend, namely fall ⇒ rise or rise ⇒ fall, were rare. Full article

The wing-in-ground (WIG) effect occurs when air pressure is created beneath a craft moving close to the ground. The pressure created adds upwards lift, resulting in less need for propulsion for moving forward. Over the years, several companies in various countries have developed wing-in-ground crafts—marine vessels, looking like airplane, that operate using the ground effect. However, no commercial routes are currently in operation using such crafts. This article seeks to identify the critical factors that contribute to the successful commercialization of WIG crafts. The study is composed of a literature review, a company comparison and an analysis of one case study close to successful commercialization. The study indicates that the following actions are critical for the commercial success of a company engaged in WIG operations: engaging community, enhancing R&D, establishing a robust technological system and focusing on safety and compliance. It is also noted that technological readiness itself does not guarantee the successful implementation of WIG crafts on commercial routes. Full article

The geochemical background value of chromium (Cr) serves as a pivotal factor in environmental assessments and mineral exploration endeavors. Traditionally, geochemical background values have been determined using statistical parameters derived from dataset analysis, though this method may possess inherent limitations. In this study, we introduce a novel equation to calculate the geochemical background value of Cr, based on the premise that major elements can effectively delineate the geochemical background for trace elements. Using a dataset encompassing 791 abundance records from rocks, soils, and sediments, we derived and fitted the equation. Our findings revealed that when treating these 791 records as representative of background samples, approximately 95% of the records lie within a logarithmic error of ±0.2 from the calculated values. Based on this observation, we propose adopting a logarithmic error threshold of ±0.2 as a criterion for identifying background samples. To further validate the equation, we tested background samples from diverse regions with varying degrees of weathering. Among the 138 samples analyzed, only two exhibited background values with a logarithmic error exceeding ±0.2 from the measured values, although all samples fell within a ±0.3 error margin. We subsequently applied this equation to the orthopyroxenite and dunite zones within the Pados-Tundra complex, located in the western Kola Peninsula, Russia. According to the ±0.2 logarithmic error criterion, mildly altered orthopyroxenite samples could be deemed as background Cr samples, where certain altered orthopyroxenite samples exhibited a logarithmic error in the ±0.2–±0.3 range. In contrast, altered and mineralized samples in the dunite zone showed a significant deviation beyond the ±0.2 error range, indicating that they should be classified as anomalous Cr samples. This innovative methodology offers a refined approach for background determination and anomaly identification, thereby enhancing mineral exploration and Cr environmental quality assessments. Full article

Streptococcus mutans is primarily found in biofilms on tooth surfaces and is associated with the development of dental caries. S. mutans synthesizes water-insoluble glucan (WIG) using sucrose as a substrate, inducing the formation of three-dimensional biofilms. WIG is produced by glucosyltransferases (GTFs) encoded by the tandem and highly homologous gtfB and gtfC genes. Conversely, the homologous recombination of gtfB and gtfC readily happens, producing natural variants without WIG. These WIG⁻ variants are thought to have ecologically pleiotropic functions; however, the molecular basis for their appearance is unclear. This study aimed to determine the sequence of the gtfB–gtfC regions of WIG⁻ variants. We sequenced the gtfB–gtfC regions of 23 WIG⁻ variants derived from S. mutans UA159 and revealed the presence of five alleles and four types of single homologous recombination patterns. Regardless of the allele type, the WIG⁻ variants showed low biofilm formation and GTF activity. To the best of our knowledge, this is the first study to report the presence of alleles in WIG⁻ variants. These findings provide important information for explaining the appearance of mechanisms in WIG⁻ variants. Full article

For several years, commercial banks in Poland have been reporting activities related to the impact on the environment, society, and corporate governance (ESG). However, only new guidelines, mandatory for many entities, including banks, will allow for comparing these reports, which will be of great importance mainly for investors. The forms of these reports were and still are different, difficult to compare in individual years, and difficult to compare between banks. The article aims to present the banks’ preparation for the new reporting rules based on the latest ESG reports. The research was conducted in four groups of commercial banks operating in Poland. These are the largest companies listed in the WIG Banks sub-index of the Warsaw Stock Exchange. Gaps in the preparation of these banks for non-financial reporting were identified. The non-financial reports of the banks studied have significant information potential that can be used by various stakeholder groups, including investors, customers, employees, regulators, and local communities. However, the comparability of ESG reports is one of the key challenges faced by both reporting banks and users of these reports. The research results can be used both in scientific works and by bank representatives to improve non-financial reports. Full article

Some very useful methods for suppressing the flow-induced vibration (FIV) of a single cylinder are known to potentially have a limited efficiency for tandem-arrangement cylinders. In this paper, three splitter plates uniformly attached around a cylinder with an angle of 120° are proposed to suppress the FIVs of both a single cylinder and two tandem-arrangement cylinders in a wind tunnel at Re = 4000–45,200. The splitter plates’ length to diameter ratios, L/Ds (where L is the length of the splitter plate and D is the cylinder diameter), are set from 0.1 to 0.8. The results show that the proposed method not only effectively suppresses the vortex-induced vibration (VIV) for a single cylinder, but also successfully mitigates the wake-induced galloping (WIG) for two tandem-arrangement cylinders. The vibrations of the single cylinders are effectively suppressed, consistently achieving suppression efficiencies over 95% for L/Ds = 0.2–0.8, with a notable peak efficiency of 98.4% at L/D = 0.2. For the two tandem-arrangement cylinders at S/D = 4.0 (where S is the center-to-center spacing between the two cylinders), the suppression efficiencies of the upstream cylinder exceed 96% for L/D = 0.2–0.8, with an optimal efficiency of 97.4% at L/D = 0.6. The downstream cylinder exhibits vibration only at L/Ds = 0.1, 0.2, and 0.4, resulting in suppression efficiencies of 80.3%, 67.1%, and 91.0%. The vibrations remain fully suppressed throughout the entire reduced velocity range for L/Ds = 0.6–0.8, reaching an optimal efficiency of 98.7% at L/D = 0.6. Three regimes of f_s/f_n characteristics can be classified for the single cylinder, and the wake structures show that shear layers develop along the front plate before attaching on the cylinder and are then offset to either side of the cylinder by the two rear splitter plates, contributing to the absence of periodic vortex shedding. Full article

(1) Background: Achieving inactive disease decreases long-term joint damage in patients with polyarticular juvenile idiopathic arthritis (polyJIA). The aim of our study was to describe average time to treatment and medication changes over time. (2) Methods: Incident polyJIA patients were retrospectively identified in the InGef and WIG2 longitudinal health claims databases. Drug escalation level changes were evaluated longitudinally and cross-sectionally across three years, as follows: no treatment, glucocorticoids (GCs) and/or non-steroidal anti-inflammatory drugs (NSAIDs), conventional synthetic disease-modifying antirheumatic drugs (csDMARDs), and biological disease-modifying antirheumatic drugs (bDMARDs). (3) Results: On average, newly diagnosed polyJIA patients received their first csDMARD prescription after 128 days and their first bDMARD prescription after 327 days. More patients were treated with csDMARDs than with bDMARDs at diagnosis; however, 24% and 12% (InGef and WIG2 databases, respectively) had no JIA treatment. After three years, 45% and 31% were not taking any treatments, while 18% and 36% were prescribed bDMARDs. Among patients initiating bDMARDs, most continued treatment for three years, with some switching to csDMARDs or discontinuing treatment. Patients treated only with csDMARDs took them longer, compared to those additionally taking other DMARDs. Patients treated with bDMARDs took them about twice as long as the csDMARDs they took prior. (4) Conclusion: A substantial number of patients with polyJIA are not treated as intensively as guidelines recommend. Full article

This article aims to assess the usefulness of excess market value added to equity as an external measure of company value creation from the perspective of meeting shareholder expectations. This measure compares the expected value as an increase in stock exchange capitalisation in relation to return on equity, equivalent to its cost, decreased by this capital, in relation to the actually achieved level of capitalisation. This paper investigates relations with other external and internal measures. This research is based on measuring value creation in WIG30 Warsaw Stock Exchange companies in 2017–2023. The assessment of the research results was based on mathematical statistics tools, the density measure and the taxonomic measure of similarity. The study tested four hypotheses. The results of this research showed that the excess measure does not distort market information and can be used to assess the effectiveness of shareholder value creation, taking into account shareholder expectations. Secondly, the paper pointed to an unsatisfactory level of value creation in WSE WIG30 companies. The negative assessment of value creation management refers both to effectiveness and efficiency. Thirdly, shareholders continue to use classical financial measures despite the existence of a wide spectrum of value measures. Fourthly, the paper points to the lack of theoretical equality between the market value added (an external measure) and capitalised economic value added (an internal measure). The presented research contributes to unbiased assessments of whether or not shareholder value is simultaneously created and realised in increased share prices (capitalisation) to a higher degree than shareholder expectations. Up to now, no such research studies have been conducted for Polish and foreign capital markets. The research methodology has practical applications in expectations-based management. Full article

Alopecia areata (AA) presents a challenging and unpredictable condition associated with substantial psychosocial and financial burdens. A chronic, relapsing form of non-scarring hair loss, it affects approximately 0.1–0.2% of the population worldwide with a lifetime risk of 1.0% to 2.1%. The psychosocial implications of AA, including its association with depression, anxiety, social phobia, employment disruption, and relationship challenges are well described. Significant economic costs of AA include those of healthcare, lost income, transportation, psychotherapy, and cosmetic accessories (wigs and hairpieces). However, wigs and hairpieces can contribute to enhanced self-esteem, confidence, and overall quality of life (QOL) in AA patients; these positive outcomes correlating with satisfaction in appearance. This article explores the role of wigs in addressing the aesthetic and emotional impact of AA, emphasizing their importance as potential coping mechanisms for individuals facing hair loss whilst also acknowledging possible barriers to their use. Different types of wigs and hairpieces, their respective advantages and disadvantages, and methods of attachment are thoroughly discussed, providing a comprehensive overview for both patients and healthcare professionals. Considering the economic impact of AA, this article explores the cost of wigs in Australia and available financial assistance programs. Wigs can play a pivotal role in rapidly addressing the multifaceted challenges posed by AA, offering time for psychosocial adaptation and delayed response to medical therapies. This review aims to provide valuable insights to inform evidence-based, practical, and personalized counselling of patients with AA and enable shared decision making about the utility of wigs and other cosmetic interventions for hair loss. Further research is warranted to explore differences in the optimal utilization of wigs between diverse sub-populations with AA. Full article

Background: Infertility affects about 80 million individuals worldwide and 10–15% of couples at reproductive age will seek medical assistance. There is increasing evidence that pregnancies after Assisted Reproduction Techniques (ART) are associated with pre-term birth, low birthweight, congenital defects, and increased mortality rates. The aim of this review is to assess all the published literature and provide an updated review on the effect of assisted conception and perinatal and neonatal outcomes. Methods: Comprehensive research on Pubmed/Medline, Scopus, and Google scholar electronic databases was conducted from July 2023 up to September 2023, using the terms assisted reproductive techniques, ART, in vitro fertilization, IVF, intracytoplasmic sperm injection, ICSI, preterm birth, PTB, low birth weight, LBW, chromosomal defects, congenital defects, and hypospadias. In total, 87 full text articles were retrieved and after a careful evaluation, 31 studies were selected for data extraction. Results: Our review demonstrated a higher risk of congenital and chromosomal defects, and a higher incidence of male genital tract defects and heart defects in ART pregnancies. Regarding pre-term birth, our results were contradictory. Conclusions: Although assisted reproduction techniques are associated with increased risks, they are safe regarding perinatal outcomes and couples should not be discouraged from utilizing them. Our results aim to alert clinicians to these specific outcomes and offer more personalized care and counseling to infertile couples and their children. Full article

With the phase-out of amalgam and the increase in minimally invasive dentistry, there is a growing need for high-strength composite materials that can kill residual bacteria and promote tooth remineralization. This study quantifies how antibacterial polylysine (PLS) and re-mineralizing monocalcium phosphate monohydrate (MCPM) affect Streptococcus mutans biofilms and the strength of dental composites. For antibacterial studies, the MCPM-PLS filler percentages were 0-0, 8-4, 12-6, and 16-8 wt% of the composite filler phase. Composite discs were immersed in 0.1% sucrose-supplemented broth containing Streptococcus mutans (UA159) and incubated in an anaerobic chamber for 48 h. Surface biomass was determined by crystal violet (CV) staining. Growth medium pH was measured at 24 and 48 h. Biofilm bacterial viability (CFU), exo-polysaccharide (water-soluble glucan (WSG) and water-insoluble glucan (WIG)), and extracellular DNA (eDNA) were quantified. This was by serial dilution plate counting, phenol-sulfuric acid microassay, and fluorometry, respectively. The biaxial flexural strengths were determined after water immersion for 1 week, 1 month, and 1 year. The MCPM-PLS wt% were 8-4, 8-8, 16-4 and 16-8. The normalized biomass, WSG, and WIG showed a linear decline of 66%, 64%, and 55%, respectively, as the PLS level increased up to 8%. The surrounding media pH (4.6) was all similar. A decrease in bacterial numbers with the 12-6 formula and a significant reduction with 16-8 compared to the 0-0 formulation was observed. The eDNA concentrations in biofilms formed on 12-6 and 16-8 formulations were significantly less than the 0-0 control and 8-4 formulations. Doubling MCPM and PLS caused a 14 and 19% reduction in strength in 1 week, respectively. Average results were lower at 1 month and 1 year but affected less upon doubling MCPM and PLS levels. Moreover, a 4% PLS may help to reduce total biomass and glucan levels in biofilms on the above composites. Higher levels are required to reduce eDNA and provide bactericidal action, but these can decrease early strength. Full article

Although the existing deblurring methods for defocused images are capable of approximately recovering clear images, they still exhibit certain limitations, such as ringing artifacts and remaining blur. Along these lines, in this work, a novel deep-learning-based method for image defocus deblurring was proposed, which can be applied to medical images, traffic monitoring, and other fields. The developed approach is equipped with wavelet transform, an iterative filter adaptive module, and graph neural network and was specifically designed for handling defocused blur. Our network exhibits excellent properties in preserving the original information during the restoration of clear images, thereby enhancing its capability to spatially address varying blurriness and improving the quality of deblurring. From the acquired experimental results, the superiority of the introduced method in the context of image defocus deblurring compared to the majority of the existing algorithms was clearly demonstrated. Full article

Wing-in-Ground (WIG) effect aircraft are gaining attention for their potential in reducing environmental impact. However, optimising wing planforms based solely on aerodynamics might improve performance while compromising static height stability of WIG aircraft. This study investigates the effects of planar and nonplanar wing planform optimisation for regional transport ground effect aircraft. Three distinct multiobjective wing planform optimisations are explored: planar wing optimisation, nonplanar wing optimisation, and nonplanar wingtip optimisation. These optimisations assess the impact on both aerodynamic efficiency and static height stability characteristics of a wing planform in ground effect, at three different flying altitudes. In extreme ground effect, the Pareto set includes wings with negative spanwise camber, enhancing both cushion sensation and aerodynamic efficiency by effectively utilizing ground effect, thus proving advantageous over planar wing configurations. Full article

The present paper aims to study the behavior of tailor welded blanks subjected to a single point incremental forming (SPIF) process from an experimental point of view. This process was chosen to deform truncated cone shapes of AA1050 aluminum alloy with different thicknesses. A uniaxial tensile test was performed to determine the mechanical characteristics of the alloy. Initial experimental tests implicated the use of variable wall angle parts which were processed on unwelded sheet blanks for determination of the behavior of the material and the forming forces. Afterwards, the wolfram inert gas (WIG) welding technique was used for joining two sheet blanks with different thicknesses either through one pass on one side, or by one pass on both sides. The conclusion of this paper indicates that one-sided welded blanks cannot be deformed successfully without fracture. In case of two-sided welded blanks, the results showed that the desired depth of 25 mm can be reached successfully. In case of the SPIF process, if welded blanks must be deformed, then the suitable method is to weld the blanks on both sides. Full article