SIMULATIONS AND ANALYSIS OF COVID-19 AS A FRACTIONAL MODEL WITH DIFFERENT KERNELS

Recently, Atangana proposed new operators by combining fractional and fractal calculus. These recently proposed operators, referred to as fractal–fractional operators, have been widely used to study complex dynamics. In this paper, the COVID-19 model is considered via Atangana–Baleanu fractal-fractional operator. The Lyapunov stability for the model is derived for first and second derivative. Numerical results have developed through Lagrangian-piecewise interpolation for the different fractal–fractional operators. We develop numerical outcomes through different differential and integral fractional operators like power-law, exponential law, and Mittag-Leffler kernel. To get a better outcome of the proposed scheme, numerical simulation is made with different kernels having the memory effects with fractional parameters. [ FROM AUTHOR] Copyright of Fractals is the property of World Scientific Publishing Company and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Possible sleep bruxism, smartphone addiction and sleep quality among Brazilian university students during COVID-19 pandemic.

Objectives: To evaluate the association of sleep bruxism activity with smartphone addiction and sleep quality among university students during COVID-19 pandemic. Material and Methods: A cross-sectional online survey with 546 university students in social distancing was conducted (May 29th to June 2nd 2020). Participants should be undergraduate and graduate students enrolled in Brazilian public/private universities. A self-completed questionnaire collected sociodemographic characteristics, academic information, and severity of possible sleep bruxism (PSB) activities (grinding, bracing, and thrusting). Students answered the Brazilian version of Pittsburgh sleep quality index (PSQI-BR) and short form of the smartphone addiction scale (SAS-SV). Descriptive statistics and multinomial logistic regression were performed (p=0.05). Results: Sample mean age was 24.9 (±5.5) years. Students with higher scores of PSQI-BR were more likely to present severe PSB-bracing (OR=1.154; 95%CI=1.057-1.260), severe PSB-grinding (OR=1.133; 95%CI=1.048-1.225) and severe PSB-thrusting (OR=1.197;95%CI=1.107-1.294). Students who had children presented 3 times more chance (OR=3.193; 95%CI=1.236-8.250) to report severe PSB-thrusting. Being female increased the chance of reporting moderate (OR=3.315; 95%CI=1.333-8.914) and severe (OR=2.940; 95%CI=1.116-7.747) PSB-thrusting. Students not enrolled in distance learning presented 2 times more chance (OR=2.638; 95%CI=1.233-5.649) of reporting moderate PSB-grinding. Students with higher scores in SAS-SV had a slight increase in the chance of presenting mild (OR=1.042; 95%CI=1.009-1.077) and moderate (OR=1.065; 95%CI=1.018-1.115) PSB-bracing, as well as mild (OR=1.044; 95%CI=1.011-1.078) and moderate (OR=1.041; 95%CI=1.005-1.077) PSB-thrusting. Conclusion: Smartphone addiction, worse sleep quality, having children, female sex and not being enrolled in distance learning were associated possible sleep bruxism during COVID-19 pandemic.

Fractal-fractional operator for COVID-19 (Omicron) variant outbreak with analysis and modeling.

The fractal-fraction derivative is an advanced category of fractional derivative. It has several approaches to real-world issues. This work focus on the investigation of 2nd wave of Corona virus in India. We develop a time-fractional order COVID-19 model with effects of disease which consist system of fractional differential equations. Fractional order COVID-19 model is investigated with fractal-fractional technique. Also, the deterministic mathematical model for the Omicron effect is investigated with different fractional parameters. Fractional order system is analyzed qualitatively as well as verify sensitivity analysis. The existence and uniqueness of the fractional-order model are derived using fixed point theory. Also proved the bounded solution for new wave omicron. Solutions are derived to investigate the influence of fractional operator which shows the impact of the disease on society. Simulation has been made to understand the actual behavior of the OMICRON virus. Such kind of analysis will help to understand the behavior of the virus and for control strategies to overcome the disseise in community.

Frequency and pattern of outpatient dental visits during the COVID-19 pandemic at hospital and community clinics.

BACKGROUND: The authors aimed to measure the frequency of dental visits before and during the COVID-19 pandemic and to evaluate whether dental visits can be predicted from demographic characteristics, socioeconomic status, oral problem diagnoses, and dental service providers. METHODS: Participants for this retrospective study were patients visiting dental care providers at hospital- and community-based outpatient clinics in Alberta, Canada. Data were retrieved from electronic databases from March 12, 2020, through September 30, 2020, and from the same period for 2018 and 2019. The COVID-19 lockdown was declared for March 12 through May 14, 2020. Data were analyzed using analysis of variance test and multiple logistic regression at α = 0.05. RESULTS: From a total of 14,319 dental visits, 5,671, 5,036, and 3,612 visits occurred in 2018, 2019, and 2020, respectively. The mean (standard deviation) frequency of daily visits was 36.69 (15.64), 32.09 (15.51), and 24.24 (14.78), respectively. Despite the overall decrease, the frequency of visits for infections, salivary problems, and temporomandibular disorders increased during the COVID-19 pandemic in 2020. Dental visits during the pandemic were associated with more complicated oral diagnoses and dental services as well as higher economic status. CONCLUSIONS: During the COVID-19 pandemic, the frequency of dental visits decreased specifically during lockdown. Patients with complicated problems requiring urgent treatments mainly visited dental clinics. Reduced access to care was observed primarily among socially disadvantaged groups. PRACTICAL IMPLICATIONS: Although guidelines and related recommendations have been effective in restoring the compromised dental system during the COVID-19 pandemic, additional modifications are needed to promote in-person visits to improve the oral health status of patients.

Effect of Vaccination to Control COVID-19 with Fractal Fractional Operator

Currently, Atangana proposed new fractal-fractional operators that had extensively used to observe the unpredictable elements of an issue. COVID-19 is a pervasive infection today and is hard to fix. In this structure, the novel operators have been used to observing the effect of vaccination in the COVID-19 model with different values of η1,η2 which are used to show the effect of vaccination. The system will be converted into disease-free according to reproductive number. We used the Atangana-Baleanu fractal-fractional operator to investigate the COVID-19 model qualitatively and quantitatively. By using fixed point theorems we proved the existence and uniqueness of the model with the Atangana-Baleanue fractal- fractional operator. A non-linear assessment helped to find out the stability of the Ulam-Hyres. We simulate the mathematical outcomes, to understand the relationship of operators in several senses, for numerous arrangements of fractional and fractal orders.