Analysis of the Solution of a Model of SARS-CoV-2 Variants and Its Approximation Using Two-Step Lagrange Polynomial and Euler Techniques

In this paper, a vaccination model for SARS-CoV-2 variants is proposed and is studied using fractional differential operators involving a non-singular kernel. It is worth mentioning that variability in transmission rates occurs because of the particular population that is vaccinated, and hence, the asymptomatic infected classes are classified on the basis of their vaccination history. Using the Banach contraction principle and the Arzela–Ascoli theorem, existence and uniqueness results for the proposed model are presented. Two different numerical approaches, the fractional Euler and Lagrange polynomial methods, are employed to approximate the model's solution. The model is then fitted to data associated with COVID-19 deaths in Pakistan between 1 January 2022 and 10 April 2022. It is concluded that our model is much aligned with the data when the order of the fractional derivative (Formula presented.). The two different approaches are then compared with different step sizes. It is observed that they behave alike for small step sizes and exhibit different behaviour for larger step sizes. Based on the numerical assessment of the model presented herein, the impact of vaccination and the fractional order are highlighted. It is also noted that vaccination could remarkably decrease the spikes of different emerging variants of SARS-CoV-2 within the population. © 2023 by the authors.

Institutional Environment and Tourism: Moderating Role of Host Countries' Health System

Tourism has gradually emerged to become a significant factor for sustainable economic growth around the globe. Along with other variables, the institutional environment has a significant influence on the growth of the tourism industry. Consequently, there are two primary goals for this study: firstly, to improve the body of knowledge already available on the institution-tourism nexus;secondly, to investigate how the health systems of the host countries contribute to the said nexus. To analyze these relations, we collected data from 50 countries across 10 years (2009-2018). We apply multiple regression analysis to a balanced panel dataset of 500 observations. Furthermore, we also used an interactive variable in conjunction with the primary independent, dependent, and control variables of the study to determine the moderating effect of the host countries' health systems. The study's findings demonstrated the significance of an efficient institutional structure in boosting tourism. Additionally, the health systems of the host nations play a significant role in strengthening the connection between institutions and tourism, especially in the post-COVID-19 period. Through the creation of institutional frameworks and health infrastructure, the study's findings will assist policymakers in developing efficient tourism policies. All of the above strategies will eventually lead to a trustworthy, safe, and healthy environment for both locals and visitors.

Diversification benefits of NFTs for conventional asset investors: Evidence from CoVaR with higher moments and optimal hedge ratios

This study investigates the risk and returns on one of the newest digital asset classes instruments, non-fungible tokens (NFTs), by accounting for tail dependence of higher-order moments and portfolio characteristics. We used a wide range of asset classes, encompassing equites, fixed income securities, and commodities, and document the desirable hedging and portfolio attributes of NFTs by employing Conditional Value-at-Risk (CoVaR) and ∆CoVaRs with various copula functions. We found that NFTs exhibit beneficial investment and hedging attributes under all market conditions, including the Covid-19 pandemic. Our findings have important implications for investors, risk managers, and regulators. © 2023 Elsevier B.V.

Tuberculosis chest X-ray detection using CNN-based hybrid segmentation and classification approach

Tuberculosis still significantly impacts the world's population, with more than 10 million people getting sick each year. Researchers have focused on developing computer-aided diagnosis (CAD) technology based on X-ray imaging to support the identification of tuberculosis, and deep learning is a popular and efficient method. However, deep learning-based CAD approaches usually ignore the relationship between the two vision tasks of specific region segmentation and classification. In this research, we introduced a novel TB-UNet, which is based on dilated fusion block (DF) and Attention block (AB) block for accurate segmentation of lungs regions and achieved the highest results in terms of Precision (0.9574), Recall (0.9512), and F1score (0.8988), IoU (0.8168) and Accuracy (0.9770). We also proposed TB-DenseNet which is based on five dual convolution blocks, DenseNet-169 layer, and a feature fusion block for the precise classification of tuberculosis images. The experiments have been performed on three chest X-ray (CXR) datasets, segmented images, and original images are fed to TB-DenseNet for better classification. Furthermore, the proposed method is tested against simultaneously three different diseases, such as Pneumonia, COVID-19, and Tuberculous. The highest results are achieved in terms of Precision (0.9567), Recall (0.9510), F1score (0.9538), and Accuracy (0.9510). The achieved results reflect that our proposed method produces the highest accuracy compared to the state-of-the-art methods. The source code is available at: https://github.com/ahmedeqbal/TB-DenseNet.Copyright © 2023 Elsevier Ltd

Examining Cancer Patients' Perceptions of the Impact of COVID-19 on Teleoncology: Findings From 15 Nigerian Outpatient Cancer Clinics.

PURPOSE: To examine cancer patients' perspectives on the impact of COVID-19 on teleoncology in Nigeria. METHODS: Data from a multicenter survey conducted at 15 outpatient clinics to 1,097 patients with cancer from April and July 2020 were analyzed. The study outcome was telemedicine, defined as patients who reported their routine follow-up visits were converted to virtual visits because of COVID-19 (coded yes/no). Covariates included patient age, ethnicity, marital status, income, cancer treatment, service disruption, and cancer diagnosis/type. Stata/SE.v.17 (StataCorp, College Station, TX) was used to perform chi-square and logistic regression analyses. P values ≤ .05 were considered statistically significant. RESULTS: The majority of the 1,097 patients with cancer were female (65.7%) and age 55 years and older (35.0%). Because of COVID-19, 12.6% of patients' routine follow-ups were converted to virtual visits. More patients who canceled/postponed surgery (17.7% v 7.5%; P ≤ .001), radiotherapy (16.9% v 5.3%; P ≤ .001), and chemotherapy (22.8% v 8.5%; P ≤ .001), injection chemotherapy (20.6% v 8.7%; P ≤ .001) and those who reported being seen less by their doctor/nurse (60.3% v 11.4%; P ≤ .001) reported more follow-up conversions to virtual visits. In multivariate analyses, patients seen less by their doctors/nurses were 14.3 times more likely to have their routine follow-ups converted to virtual visits than those who did not (odds ratio, 14.33; 95% CI, 8.36 to 24.58). CONCLUSION: COVID-19 caused many patients with cancer in Nigeria to convert visits to a virtual format. These conversions were more common in patients whose surgery, radiotherapy, chemotherapy, and injection chemotherapy treatments were canceled or postponed. Our findings suggest how COVID-19 affects cancer treatment services and the importance of collecting teleoncological care data in Nigeria.

Role of CSR in achieving customers' satisfaction and retention during COVID-19 and post-pandemic period: Empirical evidence from emerging nations

BACKGROUND: COVID-19 is an ongoing virus disease also recognized as a coronavirus pandemic that propelled the world to rethink organizational strategies during this unprecedented challenge. Although research on CSR has broadly been done over the past decades;nonetheless, how CSR can contribute a leading role in engaging the stakeholders such as customers during this pandemic period and post-pandemic is an important research gap that ought to be uncovered. OBJECTIVES: This study explores the impact of CSR on external stakeholders like customers and how organizations can dramatically sustain the relationships during the COVID-19 period. First, this study investigates the relationships between CSR and customer satisfaction (CS). Second, this study explores the relationships between CSR and customer retention (CR). Finally, the moderating impact of gender and education were examined among the proposed relationships. METHODS: Using the survey of 500 respondents, this study prospected the linkages among CSR, CS, and CR from China using a convenience sampling approach. The questionnaires were disseminated to Chinese online shoppers between Jan 2020 and March 2020 and explored using SEM model. RESULTS: It found that customers are more attached and satisfied with those organizations that are socially responsible and value their stakeholders, especially during uncertain situations like COVID-19 since presently revealed a positive relationship between CSR and CS. Second, it is found that there is a positive influence of CSR on CR as well. Finally, the study affirmed the positive nexus of gender and education as the moderators among CSR, CR, and CS. CONCLUSION: CSR is always on the front line blending social and environmental goals into business operations, especially during uncertain times and challenges. Undeniably, the COVID-19 pandemic is not only a global health emergency but is also leading to a major global challenge that drives organizations to revisit policies to sustain the relationships with their stakeholders. This study concluded the positive nexus of CSR and affirmed the positive role in sustaining relationships with customers during distinct uncertainties like COVID-19.

Perspectives of trainees and examiners on communication skills assessment during online postgraduate psychiatry examination in Ireland

Introduction: Covid-19 pandemic caused a pivot to online clinical education and assessment across the globe. Objective(s): To explore the views of psychiatric trainees and examiners on assessment of communication skills during online high stakes postgraduate examination. Method(s): This study was designed as interpretive descriptive qualitative research. All candidates and examiners of the online Irish Basic Specialist Training exam in September and November 2020 were included. The respondents were interviewed by Zoom which were transcribed verbatim. Data was coded using NVivo20 pro and Braun and Clarke thematic analysis was used to draw various themes and subthemes. Result(s): A total of seven candidates and seven examiners from different training deaneries and specialties were interviewed with average duration of 29m 45s and 24m 20s respectively. The participants were largely satisfied with the online examination but did not consider it equal to face-to-face for picking nonverbal cues. The candidates were very conscious of eye contact while examiners placed more emphasis on overall professional behavior and patient engagement. All candidates preferred to continue online format post pandemic for practical reasons e.g., avoiding travel and overnight stay, while all examiners preferred to go back to in-person Objective Structured Clinical Examination due to some limitations in assessing physical and cognitive examination. However, continuation of online Clinical Formulation and Management Examination was agreed by both groups. Conclusion(s): The results of the study have shown different insights of two important stakeholders in a professional postgraduate psychiatry examination which can be useful to improve same exam and design similar assessments in other settings.

IMPACT OF THE ONLINE LEARNING TECHNIQUES ON STUDENTS' CUMULATIVE GRADE POINTS

When COVID-19 prevailed, the educational system was shifted to online rather than traditional to facilitate the learning process. This study aimed at exploring the impacts of online learning techniques on the students' Cumulative Grade Point Average (CGPA). A total of 155 randomly selected students currently studying M. Phill education at the University of Agriculture Faisalabad, Pakistan participated in this study. Data were collected through validated, pre-tested and reliable questionnaires. Collected data were analyzed using Statistical Package for Social Sciences (SPSS). Findings unveiled that online learning techniques improved the learning abilities, personality traits and teaching styles as perceived by the respondents which further improved the CGPA of students. Within the effects on learning abilities, enabling students to judicious use of technology, multimedia, observation and clearing the concepts were major improvements which helped students to attain an increase in CGPA. As for as effects on personality traits were concerned, social interaction enhanced communication skills and improvement in understanding, social skills and confidence led the students to get high CGPA. Moreover, online learning improved the teaching styles by integrating video lectures, immediate results assessment and easy access to the technology were key drivers of the increase in CGPA. This study suggested a hybrid educational system at the University of Agriculture Faisalabad for effective learning in students.

Social, Political, Psychological Impacts of Covid-19 Digitalization of the Currency and Emerging World Order

Covid-19 commonly known as Coronavirus is the biggest challenging posing threat to the international system and the way of life we know. This paper is general in nature and aims at reaching the larger audience. This academic paper enables the readership from all walks of life to understand the nature of the pandemic and its effects on our ways of life. Central objective is to highlight that change in traditional system and domestic arena is inevitable. It brings into limelight the economic challenges digitalization of the economy, probable decline of the United States (US) as a major power, challenges posed to our social culture, pre-existing social norms and the changing norms and work ethics. Paper also highlights probability of biological terrorism and weakness of our health system. For the completion of this paper authors have conducted interviews to analyse this pandemic using empirical evidence to examine Covid-19 spread, recurring fallout, intensity and its impact on the global order. Aim of this paper is to highlight significance of artificial intelligence, transformation of world economic system based on quantum computer and continued relevance of capitalism for international order. Paper emphasises states failure to adopt to changing nature of economic order will result in collapse of its economic institutions followed by political chaos and anarchy. Authors attempt to highlight geo-economic framework based on neo-liberalism is substitute to geo-strategic framework. It is a key to survive in prevailing circumstances. © 2022, World Scientific and Engineering Academy and Society. All rights reserved.

CROSS-REACTIVITY OF COVID-19 IGG ASSAY WITH KNOWN IMMUNE-MEDIATED AND INFECTIOUS DISORDERS

Objective: To assess the cross-reactivity of COVID-19 IgG assay with known immune-mediated and infectious disorders and evaluate for any false-positive reactions to determine the specificity of the serological assay. Study Design: Cross-sectional analytical study. Place and Duration of Study: Department of Chemical Pathology, Chughtai Institute of Pathology, Lahore Pakistan, from Sep to Oct 2020. Methodology: A total of 116 samples were included in the study of both males and females. Diagnosed cases of typhoid fever, viral hepatitis, systemic lupus erythematosus (SLE), syphilis, multiple connective tissue disorders (MCTD), varicella-zoster infection, rabies, toxoplasmosis, epstein-barr virus (EBV) infection, rubella, rheumatoid arthritis, AIDS, cytomegalovirus (CMV) infection and dengue fever were included in the study. Three samples of multiparous women aged more than 40 years were also included in the study. IgG antibody levels were measured against SARS-CoV-2 with a cut-off index of 1.4. Results: Out of 116, only 3 (2%) samples were reactive for IgG against SARS-CoV-2. The categories showing cross-reactivity were typhoid, hepatitis C, and CMV. All specimens showing cross-reactivity were of females. Assay under consideration showed a specificity of 97.4%. Conclusion: Cross-reactivity was seen in pre-pandemic cases of infectious diseases with COVID-19 IgG antibody assay. Medical lab professionals must verify the serological assays before use in the clinical laboratory to avoid false-positive results. © 2021, Army Medical College. All rights reserved.

Web-based Game vs. Virtual Reality Field Surveying Labs towards Enhancing Experiential Education

Introductory surveying engineering courses include several outdoor labs that introduce students to proper use instruments and equipment. Through practice and experiential learning students develop technical skills and learn about surveying techniques and methods. In addition, through review and reflection of their surveys, students are able to reinforce concepts learned in lectures. Outdoor labs have several challenges such as being affected by weather leading to cancellations that disrupt the educational process. Moreover, the COVID-19 pandemic has introduced new challenges and forced virtualization of outdoor labs. Development of virtual and immersive technologies in the past decade have sparked applications in engineering education, offering viable alternatives, and enhancing traditional instructional approaches. Indeed, virtual reality and gamification technologies offer different learning approaches while various learning outcome can be achieved. In this paper two promising approaches, Web-based game and virtual reality, for virtualization of experiential educations and remote field delivery have been investigated. This study uses data collected in different institutions but in similar introductory surveying courses. The first dataset is from civil engineering students who used a game-based Web application to simulate topographic surveying. Being a game-based implementation, emphasis is placed on following best field practices rather than faithful replication of surveying instruments. The second dataset is from surveying engineering students who completed leveling labs in immersive and interactive virtual reality using Oculus hardware. The environment and instrument were faithfully modeled in Unity from their physical counterparts, giving a sense of realism. Both game-based and virtual reality approaches have different advantages and disadvantages, that makes them effective in different learning settings. A comparison of these two approaches demonstrates the synergies of future integrated implementation. Lessons learned will help instructors in understanding and identifying the proper technology to address experiential educational challenges that are related with virtually training engineering students. © American Society for Engineering Education, 2021

Patient's Perspective on the Impact of COVID-19 on Cancer Treatment in Nigeria.

PURPOSE: Because of the global COVID-19 pandemic, health care organizations introduced guidelines for modifications to health and cancer medical care delivery to mitigate transmission and ensure quality health outcomes. To examine the extent and impact of these modifications on oncology service disruptions in Nigeria, we surveyed oncology patients across selected public and private cancer treatment centers. MATERIALS AND METHODS: Participating in the study were 15 tertiary cancer treatment centers across 12 Nigerian states. We recruited adult patients with cancer (18+ years) on active treatment to complete a self-administered survey on cancer care during COVID-19. We conducted descriptive and multivariate data analysis using Stata 16.1. RESULTS: Respondents were (n = 1,072), female (65.7%), ages 18-49 years (50.3%), and married (80.7%). The top two cancers were breast and prostate. Overall, 17.3% of respondents reported disruptions to cancer care, and more than half (51.0%) reported difficulties accessing care. Changes in chemotherapy regimens or route of administration were reported in 8.4% of respondents. Odds for any disruption were highest for older patients, western states, patients with prostate cancer, and patients with two or more flu symptoms. Odds for radiotherapy cancellation were highest for older patients, those with prostate cancer, and those with medium service perception. CONCLUSION: This study investigated COVID-19-influenced cancer treatment disruptions in Nigeria. Patients with cancer experienced significant disruptions to cancer care. Vulnerable patients are most likely to be negatively affected. Policies and strategies aimed at minimizing service disruptions while maintaining cancer patients' safety should be a priority for all health care institutions in the COVID-19 era.

Marked efficiency enhancement of 222 nm AlGaN-based deep-UV LEDs for disinfection of SARS-2 (Covid-19)

The AlGaN-based deep ultraviolet lightemitting diodes (DUV LEDs) for the disinfection of SARS-2 (Covid-19) are proposed in this study. The optoelectronic characteristics of DUV LEDs are numerically analyzed. The results show that the internal quantum efficiency (IQE) and radiative recombination rate are excellently improved in the proposed LED. This significant enhancement is due to the optimal recombination of electron- hole pairs in the active region. This is attributed to the increase of potential barrier height for electron, which suppress the electron leakage effectively. Moreover, due to the decrease of lattice mismatch between the last quantum barrier (LQB) and EBL ease the holes transportation to the active region. Therefore, based on these results, we highly believe that this study provides a novel approach for highly efficient DUV LEDs (222 nm) for the disinfection of severe SARS-2 (Covid-19) infection.

Tourist's satisfaction with local food effect behavioral intention in COVID-19 pandemic: a moderated-mediated perspective

Purpose This study explored the relationship between local food consumption value and satisfaction with local food, leading to behavioral intention. Moreover, tourist's involvement is used as a mediator, and COVID-19 fear moderates between satisfaction with local food and behavioral intention. Design/methodology/approach Structural equation modeling (SEM) technique presents researchers with extra flexibility and better research conclusions. This study used Partial Equation Modeling SEM to test the proposed hypotheses. The convenience sampling technique was used to collect data, and 339 questionnaires were part of the final analysis. Findings The results reveal that local food consumption value is positively associated with local food satisfaction except for emotional value. Satisfaction on local food significantly determined tourist's involvement and behavioral intention. Tourist's involvement is positively related to behavioral intention. Despite this, COVID-19 fear significantly decreases behavioral intention. Tourist's involvement significantly mediates, and COVID-19 fear moderates between satisfaction with local food and behavioral intention significantly. Practical implications The results of our research will support scholars and practitioners to recognize the importance of factors that influence people's intention to eat local food. Besides, our research offers a significant policy to get maximum benefits for the tourism industry in Pakistan. Originality/value To the author's knowledge, our study initially incorporates a research model in the COVID-19 pandemic and covers local food consumption value, satisfaction on local food, tourist's involvement and COVID-19 fear to determine the behavioral intention of people to eat local food. Besides, consumption value theory was used to build a research framework.

A Conceptual Framework for Smart Social Distancing for Educational Institutes

The spread of the novel corona virus (COVID-19) has caused society to suffer to a great extent and have affected Governments and health authorities globally. COVID-19 spreads in a very fast manner due to absence of any active therapeutic agents and the lack of immunity against it. Although developed countries have started vaccination against COVID-19;however, availability of vaccines in developing countries is still an issue. Social distancing needs to be maintained in countries where vaccination is started till everyone gets vaccinated and COVID-19 is completely eradicated. To maintain social distancing, permanent lockdowns and curfews are no longer a sustainable solution due to adverse effects on economy. Therefore, there is a dire need to maintain social distancing in educational institutions. Violations of social distancing can be monitored and reported with the help of object detection and tracking techniques so that appropriate actions can be taken to prevent the minimize social distancing. We present comparison between state-of-the-art existing object detection methods and propose a conceptual framework to detect social distancing violations in higher educational institutes. Proposed framework takes live video streams as input, tracks human, and detects masks and violation of social distancing with the help of deep learning method. Our method can be implemented to monitor and reduce the effect of social distancing in educational institutions in real time environment with highest accuracy. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.

Polarization-dependent hole generation in 222 nm-band AlGaN-based Far-UVC LED: a way forward to the epi-growers of MBE and MOCVD

Far-ultraviolet-C (Far-UVC) light-emitting-diodes (LEDs) offer a promising technology for the disinfection of surface, air, water, food and airborne disease transmission in occupied spaces, including COVID-19 (SARS-CoV-2) and other viral diseases, when it is meticulously designed, engineered, and applied. Research should continue on both the safety and efficacy of AlGaN-based Far-UVC LEDs, as well as the material choices and device designs to develop highly efficient solid-state UV germicidal irradiation (UVGI) at 222 nm emission to replace toxic low-pressure mercury lamps emitting at 253.7 nm. However, the key issue of hole concentration inside the multi-quantum-wells (MQWs) of AlGaN-based Far-UVC LEDs with high Al-contents is quite critical. Therefore, theoretical studies of AlGaN-based Far-UVC LEDs may suggest sufficient evidence for immediate consideration and implementation for the epitaxial growth of 222 nm-band Far-UVC LED technology during this world-wide health crisis. In this paper, the initial design of the Al-graded p-AlGaN hole source layer (HSL) on the performances of Far-UVC LED was compared with conventional bulk p-AlGaN HSL (non-graded)-based LED devices. For the evaluation of the device's performances, the energy band diagram, internal quantum efficiency (IQE), electrons and holes concentration, radiative recombination rate, and current density vs voltage characteristic were compared. It was found that LEDs at 222 nm emission without using the undoped (ud)-AlGaN final-quantum-barrier (FQB) and only keeping the Al-graded Mg-doped p-AlGaN HSL showed high carrier injection into the MQWs. The variation in the energy band diagram around the p-AlGaN electron-blocking layer (EBL)/p-AlGaN HSL region and p-AlGaN HSL/p-GaN contact-layer (CL) indicates that the introduction of the Al-graded p-AlGaN HSL, as well as the special choice of Al composition at the interfaces, are quite promising for the enhancement of hole injection toward MQWs. The simulation results suggest that the proposed structure of the Al-graded p-AlGaN HSL after omitting the ud-AlGaN FQB structure in the Far-UVC LED is quite useful for achieving high peak efficiency, as well as for suppressing the efficiency droop when compared to the conventional bulk Far-UVC LED. After introducing a new design of 40 nm-thick p-AlGaN HSL in the Far-UVC LED, the radiative recombination rate in the first two quantum-wells of MQWs has been improved up to similar to 50%. The enhanced radiative recombination rate is attributed to the enhanced level of electron and hole concentrations by similar to 26% and 53%, respectively, in the MQWs. Ultimately, after removing the ud-AlGaN FQB and using 40 nm-thick Al-graded (Al: 100% to 20%) p-AlGaN HSL, the efficiency droop has been remarkably reduced from similar to 39% (Bulk-LED) to similar to 19% in the new design of Far-UVC LED structure.

Optimizing Energy in WiFi Direct Based Multi-hop D2D Networks

The recent pandemic of COVID-19 has changed the way people socially interact with each other. A huge increase in the usage of social media applications has been observed due to quarantine strategies enforced by many governments across the globe. This has put a great burden on already overloaded cellular networks. It is believed that direct Device-to-Device (D2D) communication can offload a significant amount of traffic from cellular networks, especially during scenarios when residents in a locality aim to share information among them. WiFi Direct is one of the enabling technologies of D2D communications, having a great potential to facilitate various proximity-based applications. In this work, we propose power saving schemes that aim at minimizing energy consumption of user devices across D2D based multi-hop networks. Further, we provide an analytical model to formulate energy consumption of such a network. The simulation results demonstrate that a small modification in the network configuration, such as group size and transmit power can provide considerable energy gains. The observed energy consumption is reduced by 5 times for a throughput loss of 12 %. Additionally, we measure the energy per transmitted bit for different configurations of the network. Furthermore, we analyze the behavior of the network, in terms of its energy consumption and throughput, for different file sizes.