Initial Phase Research Articles

Food insecurity in Malaysia: assessing the impact of movement control order during the COVID-19 pandemic

Purpose This study aims to assess the household food insecurity in Malaysia during the initial phase of the movement control order (MCO) to provide insights into the prevalence and predictors of food insecurity in this context. Design/methodology/approach The research used an online cross-sectional survey between March 28 and April 28, 2020. The study collected data from the Radimer/Cornell Hunger Scale and a food insecurity instrument. Analytical tools included chi-square and logistic regression models. Findings Of the 411 participating households, 54.3% were food-secure, while 45.7% experienced varying food insecurity. Among these, 29.9% reported mild hunger-associated food insecurity, 8.5% experienced individual food insecurity and 7.3% reported child hunger. The study identified predictors for food insecurity, including household income, as those with total income of < RM 2,300 had 13 times greater odds (odds ratio [OR] 13.8; confidence interval [CI] 5.9–32.1; p < 0.001) than those with income of RM 5,600, marital status as divorced (OR 4.4; 95% CI 1.0–19.9; p-value = 0.05) or married (OR 1.04; 95% CI 0.52–2.1) compared to those who are single. Self-employed respondents had three times greater odds of living in a household experiencing food insecurity (OR 3.58; 95% CI 1.6–7.7; p-value = 0.001) than those in the private sector (OR 1.48; 95% CI 0.85–2.61) or experiencing job loss (OR 1.39; 95% CI 0.62–3.1) compared with those who reported being in full-time government employment. Research limitations/implications This study acknowledged limitations, such as not considering various dimensions of food insecurity, such as coping strategies, nutritional support, diet quality and well-being, due to the complexity of the issue. Practical implications The study underscores the importance of targeted support for vulnerable groups and fostering collaborative efforts to address household food insecurity during crises like the MCOs. Social implications The research offers insights into how to address household food insecurity and its impact on society. Originality/value It identifies predictors, quantifies increased odds and emphasizes the necessity of targeted policies and collaborative approaches for fostering resilient recovery and promoting well-being in vulnerable populations.

A simulation-based approach to target Zika virus RNA-dependent RNA polymerase with marine compounds for antiviral development

Despite significant efforts, currently, there is no particular drug available to treat Zika virus (ZIKV) infection, highlighting the urgent need for effective therapeutic interventions. To identify putative inhibitors of the ZIKV RdRp protein’s RNA binding function, the present study applied an extensive in-silico drug discovery methodology. The initial phase involved virtual screening using Lipinski’s rule of five as a filter, ensuring the selection of molecules with favorable pharmacokinetic properties. This process yielded 238 compounds with promising docking scores, ranging from −6.0 to −7.48 kcal/mol, indicative of their potential binding affinity to the ZIKV RdRp. To refine the selection, these compounds underwent a re-docking process, comparing their binding energies with a reference molecule known for its inhibitory action against RdRp. Remarkably, five compounds, labeled CMNPD30598, CMNPD27464, CMNPD25971, CMNPD27444, and CMNPD16599, demonstrated superior re-docking energies compared to the reference, suggesting a stronger interaction with the RdRp allosteric site. Subsequent molecular dynamics (MD) simulations provided insights into the stability of these complexes over time, reinforcing their potential as RdRp inhibitors. Additionally, the calculation of free binding energies and principal component analysis (PCA) of the free energy landscape offered a deeper understanding of the binding dynamics and energetics. This study not only highlights the utility of marine fungi compounds in antiviral drug discovery but also showcases the power of computational tools in identifying novel therapeutics. The identified compounds represent promising candidates for further experimental validation and development as ZIKV RdRp inhibitors. Communicated by Ramaswamy H. Sarma

Development and application of a home-based exercise program for patients with cardiovascular disease: a feasibility study

BackgroundCardiac rehabilitation (CR) is recommended for patients with cardiovascular disease. However, the participation and completion rates for hospital-based CR are low, and home-based CR has been suggested as an alternative. This study aimed to develop a home-based CR program and assess the feasibility of the program over a 6-week period in patients with left ventricular dysfunction or a history of myocardial infarction.MethodsThis feasibility study consisted of two phases. The initial phase (Study 1) focused on developing the home-based exercise protocol. Systematic approaches to developing evidence-based home-based exercise intervention were implemented including systematic review, patient surveys, and expert consensus. Study 2 aimed to evaluate the feasibility of a 6-week home-based CR program that was based on the results of Study 1. Study 2 included two exercise education sessions and four telephone counseling sessions. During this stage of the exercise program, the participants exercised on two separate days and their experiences while performing the aerobic and resistance exercises were surveyed. Eight participants participated in Study 1 and 16 participated in Study 2.ResultsParticipants expressed overall satisfaction with the exercise program in Study 1. Heart rate increased in response to exercise, but this did not correspond with perceived exertion. The aim of the home-based CR exercise program was for participants to achieve exercise goals (≥150 min/week of aerobic type exercises as well as at least twice weekly resistance exercise using own body weights). We aimed to increase compliance and adherence to the home-based CR program. In Study 2, 13 out of 16 participants (81.3%) completed the 6-week home-based CR program, with a participation rate of 100% in both exercise education and phone counseling sessions. Adherence to the home-based exercise protocol was 83.1% and no serious adverse events were observed. At the beginning of the study, only three out of 13 participants (23.1%) met the requirements for both aerobic and resistance exercises, but at the end of the 6-week program, 10 out of 13 participants (76.9%) fulfilled the requirements.ConclusionThe exercise program developed in this study was safe and feasible, and the 6-week home-based CR program was feasible for patients with cardiovascular disease without any reported adverse effects.

Initial development of skill with a reversed bicycle and a case series of experienced riders

Riding a bicycle is considered a durable skill that cannot be forgotten. Here, novice participants practiced riding a reversed bicycle, in which a reversing gear inverted the handlebar’s rotation. Although learning to ride the reversed bicycle was possible, it was slow, highly variable, implicit, and followed an S-shape pattern. In the initial learning phase, failed attempts to ride the normal bicycle indicated strong interference between the two bicycle skills. While additional practice decreased this interference effect, a subset of learners could not ride either bicycle after eight sessions of practice. Experienced riders who performed extensive practice could switch bicycles without failed attempts and exhibited similar performance (i.e., similar handlebar oscillations) on both bicycles. However, their performance on the normal bicycle was worse than that of the novice bicycle riders at baseline. In conclusion, “unlearning” of the normal bicycle skill precedes the initial learning of the reversed bicycle skill, and a signature of such unlearning is still present following extensive practice.

Exploration of the protective mechanisms of Icariin against cisplatin-induced renal cell damage in canines.

This study delves into the protective mechanisms of Icariin (ICA) against cisplatin-induced damage in Madin-Darby canine kidney (MDCK) cells. Comprising two distinct phases, the investigation initially employed a single-factor randomized design to ascertain the minimal cisplatin concentration eliciting MDCK cell damage, spanning concentrations from 0 to 16 mmol/L. Concurrently, various concentrations of ICA (ranging from 5 to 50 mmol/L) were combined with 1 mmol/L cisplatin to determine the most efficacious treatment concentration. Subsequent investigations utilized four treatment groups: control, 1 mmol/L cisplatin, 1 mmol/L cisplatin + 20 mmol/L ICA, and 1 mmol/L cisplatin + 25 mmol/L ICA, aimed at elucidating ICA's protective mechanisms. Findings from the initial phase underscored a significant reduction in MDCK cell viability with 1 mmol/L cisplatin in comparison to the control (P < 0.01). Notably, the inclusion of 20 and 25 mmol/L ICA substantively ameliorated MDCK cell viability under 1 mmol/L cisplatin (P < 0.01). Moreover, cisplatin administration induced an elevation in inflammatory factors, malondialdehyde (MDA), reactive oxygen species (ROS), and Bax protein levels, while concurrently suppressing superoxide dismutase (SOD), catalase (CAT), and Bcl-2 expression (P < 0.01). Conversely, supplementation of 20 and 25 mmol/L ICA demonstrated a marked increase in mitochondrial membrane potential and levels of SOD, CAT, and Bcl-2 (P < 0.01). These interventions effectively attenuated inflammatory responses and suppressed Bax protein expression (P < 0.05), consequently mitigating cisplatin-induced apoptosis in MDCK cells (P < 0.01). In summary, these findings elucidate the role of ICA in impeding apoptosis in cisplatin-induced MDCK cells by regulating inflammatory responses, oxidative stress, and autophagic protein expression.

Study of the shot peening surface roughness in fretting

Fretting fatigue manifests in mechanical systems exposed to contact forces that vary over time, resulting in premature cracks that can lead to component failure. Shot peening treatment is one of the palliatives to mitigate fretting fatigue problems. Recent studies have noted that the fretting fatigue is also extended by exclusively applying SP to the contact pad surface. This suggests that the improvement in the fatigue live produced by SP comes not only from the compressive residual stresses but also due to the characteristic surface roughness from the SP treatment. For this reason, the main goal of this work is to analyse how the shot peened roughness affects the fretting fatigue life. To do so, a confocal microscope was used to measure various profiles of shot peened pads. Using these profiles, and under fretting loads combination, the contact stress and strain field are calculated, followed by the application of a fatigue model. Finally, the estimated fatigue life is contrasted with empirical data derived from a research published by the authors. The study reveals that the fretting fatigue life is influenced by the surface roughness, although to a lesser extent with respect to residual stresses. Besides, the Smith-Watson-Toper parameter and stress intensity factor were analysed, suggesting that the rough surface primarily affects the initiation phase rather than the propagation phase, as it was expected.

Frequency response of the non-polarization-maintaining depolarized sagnac interferometer based on maximum fringe contrast

The Sagnac Interferometer offers a promising solution to the speckle problem in interferometric detection due to its insensitivity to environmental low-frequency interference, making it well-suited for applications such as laser ultrasonic detection. Control of the polarization state of light is imperative for achieving high sensitivity in optical fiber interferometer and ensuring optimal quiescent operating conditions. This study employed the coherence matrix method to analyze the theory of optimal polarization control in a non-polarization-maintaining depolarized Sagnac Interferometer, encompassing the deduction of the stable π/2 initial phase bias and the maximum fringe contrast of 50% in theory. In experimental observations during PZT simulated large amplitude ultrasound experiments, the fringe contrast reached 48.4%. Furthermore, the system's amplitude-frequency response was evaluated using an electro-optics phase modulator, demonstrating its capability to detect high-frequency signals within 100 MHz These findings provide essential insights into optimizing the Sagnac Interferometer's performance for laser ultrasonic detection and its potential applications in high-frequency signal detection and ultrasonic amplitude measurement.

Parallels and Divergences in Marxist Humanist Approach to Art in Croatia during the 1960s and 1970s

Based on reading and interpreting the key texts on the topic, the article explores the parallels and divergences between Matko Meštrović’s theory of the Neo-Avantgarde art practices of the New Tendencies and the Marxist Humanist intellectuals of the Praxis school of thought, in relation to different Marxist approaches to art in Yugoslavia. Both currents were critical, utopian, and avantgarde in nature, advocating for radical social transformation towards a new society and a new human, which they shared with the Yugoslav experimental model of self-management socialism in its initial phase. Despite these common approaches, the article argues that there was no direct connection between Yugoslav Neo-Marxists and Neo-Avantgarde artists and theoreticians. This assertion is reinforced by their different approaches to art and art history.

Methionine oxidation of carbohydrate-active enzymes during white-rot wood decay.

White-rot fungi employ secreted carbohydrate-active enzymes (CAZymes) along with reactive oxygen species (ROS), like hydrogen peroxide (H2O2), to degrade lignocellulose in wood. H2O2 serves as a co-substrate for key oxidoreductases during the initial decay phase. While the degradation of lignocellulose by CAZymes is well documented, the impact of ROS on the oxidation of the secreted proteins remains unclear, and the identity of the oxidized proteins is unknown. Methionine (Met) can be oxidized to Met sulfoxide (MetO) or Met sulfone (MetO2) with potential deleterious, antioxidant, or regulatory effects. Other residues, like proline (Pro), can undergo carbonylation. Using the white-rot Pycnoporus cinnabarinus grown on aspen wood, we analyzed the Met content of the secreted proteins and their susceptibility to oxidation combining H218O2 with deep shotgun proteomics. Strikingly, their overall Met content was significantly lower (1.4%) compared to intracellular proteins (2.1%), a feature conserved in fungi but not in metazoans or plants. We evidenced that a catalase, widespread in white-rot fungi, protects the secreted proteins from oxidation. Our redox proteomics approach allowed the identification of 49 oxidizable Met and 40 oxidizable Pro residues within few secreted proteins, mostly CAZymes. Interestingly, many of them had several oxidized residues localized in hotspots. Some Met, including those in GH7 cellobiohydrolases, were oxidized up to 47%, with a substantial percentage of sulfone (13%). These Met are conserved in fungal homologs, suggesting important functional roles. Our findings reveal that white-rot fungi safeguard their secreted proteins by minimizing their Met content and by scavenging ROS and pinpoint redox-active residues in CAZymes.IMPORTANCEThe study of lignocellulose degradation by fungi is critical for understanding the ecological and industrial implications of wood decay. While carbohydrate-active enzymes (CAZymes) play a well-established role in lignocellulose degradation, the impact of hydrogen peroxide (H2O2) on secreted proteins remains unclear. This study aims at evaluating the effect of H2O2 on secreted proteins, focusing on the oxidation of methionine (Met). Using the model white-rot fungi Pycnoporus cinnabarinus grown on aspen wood, we showed that fungi protect their secreted proteins from oxidation by reducing their Met content and utilizing a secreted catalase to scavenge exogenous H2O2. The research identified key oxidizable Met within secreted CAZymes. Importantly, some Met, like those of GH7 cellobiohydrolases, undergone substantial oxidation levels suggesting important roles in lignocellulose degradation. These findings highlight the adaptive mechanisms employed by white-rot fungi to safeguard their secreted proteins during wood decay and emphasize the importance of these processes in lignocellulose breakdown.

Active trachoma: enhancing image classification using pretrained SOTA models and explainable AI

BackgroundTrachoma, an infectious disease that leads to blindness, continues to pose a significant public health challenge in over 40 countries as of 2023. The initial phase of this disease, “active trachoma” is characterized by inflammation and can be effectively treated with non-surgical interventions. However, if left untreated, it progresses to the “scarring” phase, often requiring surgical intervention. Earlier detection of “active trachoma” is critical to prevent unnecessary surgery and also to reduce the transmission of the infection. Developing accessible tools for a region with limited resources is necessary. Deep neural networks have proven their effectiveness in numerous image and vision-related tasks, yet research on “active trachoma” has received still little attention.MethodIn this study, we adapted several pre-trained state-of-the-art deep neural network models like ResNet, Xception from image classification on “active classification” task. Further experiments were also conducted in three cases: training from scratch, training from pretrained models on raw images and on region-of-interest (ROI) focused images.Results and discussionThe results indicate that these models outperformed the previous studies using the same dataset, achieving an improvement of 6\% on detection of follicular trachomatous inflammation and 12\% for detection of intense trachomatous inflammation. Furthermore, we employed the eXplainable Artificial Intelligence tool Grad-CAM, which revealed a significant discrepancy between eyelid's geometric centroid and attention centroid from models with high classification accuracy. This finding suggests that the conventional method of selecting a region of interest based on the geometric centroid may need to be adjusted. Using XAI can offer valuable insights into understanding the classification and progression of active trachoma.

Neogene carbonate platform development in the southern South China Sea: Evidence from calcareous microfossils

Biogenic reefs are unique geologic bodies that are the products of biological activity in tropical and subtropical oceans and critical to global carbon cycling. The South China Sea (SCS) has developed largest carbonate platforms in the Western Pacific. The fully-cored Well NK-1, which is drilled through the reef complex on the Meiji Atoll, Nansha Islands, offers good opportunity for assessing the long-term evolutions of biogenic reefs in the SCS. The stratigraphic ages based on palaeomagnetic and Sr isotopic data are controversial in some intervals of core NK-1. To reveal the evolution history of Nansha Islands and their controlling factors, more credible age constraints on core NK-1 are needed. This research presents new records of calcareous microfossils (calcareous nannofossil and foraminifer) abundances and diversities in the biogenic reef carbonates of core NK-1. Based on the assemblages of the calcareous microfossils, seven biostratigraphic datums are recognized from the sequence of core NK-1, revealing a general continuous succession of the earliest Miocene to Pleistocene age. By combining with the magnetostratigraphic data, the development and evolution of carbonate platform in Nansha Islands are reconstructed. The bottom age of the biogenic reef sequence of NK-1 is estimated for 23.03 ± 1.06 Ma, close to the Oligocene/Miocene boundary. The new chronology highlights three short hiatuses of 3.6–2.4 Ma, 11.1–10.0 Ma, and 13.5–11.9 Ma, which are well correlated with the prominent exposed surfaces at 210.3 m, 464.6 m and 561.6 m, respectively. It reveals remarkably similar evolution history of carbonate platforms in the SCS since Neogene by comparing with records of stratigraphy and growth rate from deep drilling cores on isolated coral reefs in Nansha and Xisha Islands. The results showed that the SCS carbonate platform developments, which go through Late Oligocene / Early Miocene initiation phase, Early-Middle Miocene rapid growth phase, Middle-Late Miocene erosion phase, Miocene-Pliocene stable development phase and Quaternary growth phase, are mainly influenced by global sea level changes, environmental factors and regional tectonism such as the SCS basin spreading, Sabah Orogeny Movement and Dongsha Movement.

Experimental CIGS technology performance under low concentration photovoltaic conditions

This research study assesses the influence of the concentration factor on two different PV technologies: c-Si and CIGS, to analyze the feasibility of utilizing CIGS thin-film technology in Low Concentration Photovoltaic conditions. Additionally, the importance of the encapsulation design is explored to determine the optimum thermal management strategy. The initial phase involves an analysis of the thermal performance of two types of commercial photovoltaic module and explores the enhancement of temperature management in CIGS photovoltaics modules by substituting the rear glass backsheet with an aluminum sheet to reduce the operating temperature of the prototype. Subsequently, various prototypes are fabricated, incorporating CIGS and silicon technologies, and different encapsulation designs: tedlar, glass and aluminum backsheets. The analysis reveals that comparing performance under 2.2× and 1× concentration conditions, CIGS technology exhibits the higher performance at 2.2×, making it a more promising choice for LCPV systems. While CIGS technology boasts an intrinsic advantage because of its open circuit voltage temperature coefficient, its performance enhancement under LCPV conditions is further amplified through the optimization of the backsheet to improve the thermal management.

Optimization of Intelligent-Reflecting-Surface-Enabled Covert Communication in Multi-Sensor Systems

This study investigates covert communication in multi-sensor systems employing Intelligent Reflecting Surfaces (IRSs). Different from previous works, we focus on optimizing transmission amplitudes and phase angles for a 2-BPSK codebook in the presence of asymmetric noise over complex Gaussian channels. We adopt KL divergence as a covertness constraint and mutual information as a metric for transmission rate. We employ Taylor series expansion to approximate KL divergence and mutual information. Leveraging these approximations, we derive optimal phase angles through a proposed gradient descent algorithm. The numerical simulations validate the effectiveness and precision of our Taylor approximation method. Through validation in different scenarios, our algorithm demonstrates robust convergence, deriving all optimal phase angles. Comparing initial phase angles from prior works to those obtained via our algorithm, we observe a higher covert transmission rate.

Prospective learning curve analysis of en bloc resection of bladder tumor using an ex vivo porcine model

BackgroundAs a relatively new surgical technique, the learning curve of en bloc resection of bladder tumor (ERBT) in ex vivo models remains unaddressed. This study aimed to explore the learning curve of ERBT in an ex vivo porcine model.MethodsIn this prospective study, eight endoscopists without prior experience in ERBT were divided into two groups: junior endoscopists, with less than 100 transurethral resection of bladder tumor (TURBT) procedure experience, and senior endoscopists, with at least 100 TURBT procedure experience. Each endoscopist performed 30 ERBT procedures on artificial lesions in an ex vivo porcine bladder model. The procedure time, perforation, en bloc resection status, and absence of detrusor muscle (DM) were recorded. The inflection points were identified using cumulative sum (CUSUM) analysis. Procedure results were compared between the two phases and two groups.ResultsIn all, 240 artificial lesions were successfully resected using ERBT. The CUSUM regression line indicated the inflection point at the 16th procedure for the junior endoscopists and at the 13th procedure for the senior endoscopists. In both groups, the procedure time, perforation, piecemeal resection, and DM absence rates were significantly lower in the consolidation phase than in the initial phase. The procedure time for the senior endoscopists was lower than for the junior endoscopists in both phases.ConclusionsERBT performance improved significantly after reaching the inflection point of the learning curve in the ex vivo model. We recommend a minimum of 16 ERBT procedures in ex vivo models for urologists with less than 100 TURBT experience and a minimum of 13 procedures for those with at least 100 TURBT experience before advancing to live animal training or supervised clinical practice.

Teaching computer architecture by designing and simulating processors from their bits and bytes.

Teaching computer architecture (Comp-Arch) courses in undergraduate curricula is becoming more of a challenge as most students prefer software-oriented courses. In some computer science/engineering departments, Comp-Arch courses are offered without the lab component due to resource constraints and differing pedagogical priorities. This article demonstrates how students working in teams are motivated to study the Comp-Arch course and how instructors can increase student motivation and knowledge by taking advantage of hands-on practices. The teams are asked to design and implement a 16-bit MIPS-like processor with constraints as a specific instruction set, and limited data and instruction memory. Student projects include following three phases, namely, design, desktop simulator implementation, and verification using hardware description language (HDL). In the design phase, teams develop their Comp-Arch to implement specified instructions. A range of designs resulted, e.g., (a) a processor with extensive user-defined instructions resulting in longer cycle times (b) a processor with a minimal instruction set but with a faster clock cycle time. Next, teams developed a desktop simulator in any programming language to execute instructions on the architecture. Finally, students engage in Verilog Hardware Description Language (HDL) projects to simulate and verify the data-path designed during the initial phase. Student feedback and their current understanding of the project were collected through a questionnaire featuring varying Likert scale questions, some with a ten-point scale, and others with a five-point scale. Results of the survey show that the hands-on approach increases students' motivation and knowledge in the Comp-Arch course, which is centered around computer system design principles. This approach can also be effectively extended to related courses, such as Microprocessor Design, which delves into the intricacies of creating and implementing microprocessors or central processing units (CPUs) at the hardware level. Furthermore, the present study demonstrates that interactions, specifically through peer reviews and public presentations, between students in each phase increases their knowledge and perspective on designing custom processors.

Survival analysis of the duration of rumors during the COVID-19 pandemic.

The emergence of the COVID-19 pandemic towards the end of 2019 triggered a relentless spread of online misinformation, which significantly impacted societal stability, public perception, and the effectiveness of measures to prevent and control the epidemic. Understanding the complex dynamics and characteristics that determine the duration of rumors is crucial for their effective management. In response to this urgent requirement, our study takes survival analysis method to analyze COVID-19 rumors comprehensively and rigorously. Our primary aim is to clarify the distribution patterns and key determinants of their persistence. Through this exploration, we aim to contribute to the development of robust rumor management strategies, thereby reducing the adverse effects of misinformation during the ongoing pandemic. The dataset utilized in this research was sourced from Tencent's "Jiao Zhen" Verification Platform's "Real-Time Debunking of Novel Coronavirus Pneumonia" system. We gathered a total of 754 instances of rumors from January 18, 2020, to January 17, 2023. The duration of each rumor was ascertained using the Baidu search engine. To analyze these rumors, survival analysis techniques were applied. The study focused on examining various factors that might influence the rumors' longevity, including the theme of the content, emotional appeal, the credibility of the source, and the mode of presentation. Our study's results indicate that a rumor's lifecycle post-emergence typically progresses through three distinct phases: an initial rapid decline phase (0-25days), followed by a stable phase (25-1000days), and ultimately, an extinction phase (beyond 1000days). It is observed that half of the rumors fade within the first 25days, with an average duration of approximately 260.15days. When compared to the baseline category of prevention and treatment rumors, the risk of dissipation is markedly higher in other categories: policy measures rumors are 3.58 times more likely to perish, virus information rumors have a 0.52 times higher risk, epidemic situation rumors are 4.86 times more likely to die out, and social current affairs rumors face a 2.02 times increased risk. Additionally, in comparison to wish rumors, bogie rumors and aggression rumors have 0.26 and 0.27 times higher risks of dying, respectively. In terms of presentation, graphical and video rumors share similar dissolution risks, whereas textual rumors tend to have a longer survival time. Interestingly, the credibility of the rumor's source does not significantly impact its longevity. The survival time of rumors is strongly linked to their content theme and emotional appeal, whereas the credibility of the source and the format of presentation have a more auxiliary influence. This study recommends that government agencies should adopt specific strategies to counter rumors. Experts and scholars are encouraged to take an active role in spreading health knowledge. It's important for the public to proactively seek trustworthy sources for accurate information. Media platforms are advised to maintain journalistic integrity, verify the accuracy of information, and guide the public towards improved media literacy. These actions, collectively, can foster a collaborative alliance between the government and the media, effectively combating misinformation.

Metasurface for Engineering Superimposed Ince-Gaussian Beams.

Ince-Gaussian beams (IGBs) are the third complete family of exact and orthogonal solutions of the paraxial wave equation and have been applied in many fields ranging from particle trapping to quantum optics. IGBs play a very important role in optics as they represent the exact and continuous transition modes connecting Laguerre-Gaussian and Hermite-Gaussian beams. The method currently in use suffers from the high cost, complexity, and large volume of the optical system. The superposition of IGBs can generate complicated structured beams with multiple phase and polarization singularities. A metasurface approach is proposed to realizing various superpositions of IGBs without relying on a complicated optical setup. By superimposing IGBs with even and odd modes, multiple phase, and polarization singularities are observed in the resultant beams. The phase and polarization singularities are modulated by setting the initial phase in the design and controlling the incident linear polarization. The compactness of the developed metasurface devices and the unique properties of the generated beams have the potential to impact many practical applications such as particle manipulation, orbital angular momentum spectrum manipulation, and optical communications.

Smith–Watson–Topper Parameter in Partial Slip Bimodal Oscillations of Axisymmetric Elastic Contacts of Similar Materials: Influence of Load Protocol and Profile Geometry

Based on a very fast numerical procedure for the determination of the subsurface stress field beneath frictional contacts of axisymmetric elastic bodies under arbitrary 2D oblique loading, the contact mechanical influences of loading parameters and contact profile geometry on the Smith–Watson–Topper (SWT) fatigue crack initiation parameter in elastic fretting contacts with superimposed normal and tangential oscillations are studied in detail. The efficiency of the stress calculation allows for a comprehensive physical analysis of the multi-dimensional parameter space of influencing variables. It is found that a superimposed normal oscillation of the contact can significantly increase or decrease the SWT parameter, depending on the initial phase difference and frequency ratio between the normal and tangential oscillation. Written in proper non-dimensional variables, the rounded flat punch always exhibits smaller values of the SWT parameter, compared to a full paraboloid with the same curvature, while the truncated paraboloid exhibits larger values. A small superimposed profile waviness also significantly increased or decreased the SWT parameter, depending on the amplitude and wave length of the waviness. While both the load protocol and the profile geometry can significantly alter the SWT parameter, the coupling between both influencing factors is weak.

Attempts to Use Hemp (Cannabis sativa L. var. sativa) Inflorescence Extract to Limit the Growth of Fungi Occurring in Agricultural Crops

The primary objective of this investigation was to assess the potential applicability of hemp (Cannabis sativa L. var. sativa) lateral inflorescence extract in mitigating the growth of fungi, including phytopathogens, on agricultural plants. The extract, comprising a blend of biologically active compounds, holds promise for integration into contemporary plant protection methodologies. The research involved a comprehensive analysis of the extract’s chemical composition, encompassing the determination of total polyphenol and flavonoid content (utilizing spectrophotometric methods), antioxidant activity (evaluated through the DPPH method employing synthetic 2,2-diphenyl-1-picrylhydrazyl radical), and cannabinoid content (analyzed using HPLC techniques). Additionally, this study employed the poisoned substrate method to gauge the impact of 5, 10, and 20% extract concentrations on the growth of various microfungi, including Alternaria alternata, Botrytis cinerea, Colletotrichum coccodes, Fusarium avenaceum, F. culmorum, F. graminearum, F. oxysporum, F. sporotrichioides, and Trichoderma koningii. The hemp extract demonstrated a substantial presence of total polyphenolic compounds, with polyphenol and flavonoid concentrations measuring 149.65 mg/mL and 1.55 mg/mL, respectively. Furthermore, the extract contained cannabinoids at a concentration of 0.12%. The most pronounced antifungal activity was observed with the 20% extract, particularly against T. koningii (62.22–84.79%), C. coccodes (61.65–81.82%), and B. cinerea (45.00–75.42%). However, the efficacy of hemp extracts exhibited large differences against Fusarium spp. (3.10–72.95%), dependent on the specific extract and fungus strain. Introduction of hemp extracts to the substrate induced a reduction in substrate pigment and a discernible color alteration in the mycelium to a lighter shade compared to the control. These findings mark the initial phase in the exploration of practical applications for plant extracts, setting the groundwork for subsequent field trials to ascertain the extract’s impact on phytotoxicity and the health status of agricultural plants.

Measurement of nonlinear three-wave interaction using shear-vertical-wave point-focusing electromagnetic acoustic transducers

Abstract We developed a method of nonlinear three-wave interaction using shear-vertical-wave point-focusing electromagnetic acoustic transducers (SV-wave PF-EMATs). EMATs can excite and detect ultrasonic waves without couplants through interaction between electromagnetic fields and solid mechanics and are generally unsuitable for the nonlinear ultrasound measurement due to their low signal conversion efficiency. However, our originally developed PF-EMAT can focus SV waves at a focal point in phase, achieving a large local displacement. Here, two PF-EMATs with different driving frequencies are placed facing each other so as to match their focal points, where the focused SV waves intersect to induce the third waves with the frequencies of the sum and difference of the incident frequencies through the nonlinear three-wave interaction. We demonstrate that the local nonlinearity can be measured by this method with EMATs and demonstrate its applicability to evaluation of fatigue damage in a fatigue crack initiation phase with aluminum alloy specimens.