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A simulation of undiagnosed population and excess mortality during the COVID-19 pandemic. RESULTS IN CONTROL AND OPTIMIZATION 2023; 12:100262. [PMCID: PMC10290741 DOI: 10.1016/j.rico.2023.100262] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 06/19/2023] [Accepted: 06/20/2023] [Indexed: 06/21/2024]
Abstract
Whereas the extent of outbreak of COVID-19 is usually accessed via the number of reported cases and the number of patients succumbed to the disease, the officially recorded overall excess mortality numbers during the pandemic waves, which are significant and often followed the rise and fall of the pandemic waves, put a question mark on the above methodology. Gradually it has been recognized that estimating the size of the undiagnosed population (which includes asymptomatic cases and symptomatic cases but not reported) is also crucial. Here we used the classical mathematical SEIR model having an additional compartment, that is the undiagnosed group in addition to the susceptible, exposed, diagnosed, recovered and deceased groups, to link the undiagnosed COVID-19 cases to the reported excess mortality numbers and thereby try to know the actual size of the disease outbreak. The developed model wase successfully applied to relevant COVID-19 waves in USA (initial months of 2020), South Africa (mid of 2021) and Russia (2020–21) when a large discrepancy between the reported COVID-19 mortality and the overall excess mortality had been noticed.
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2
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Wu Z, Zhang W, Zeng X. Exploring the short-term and long-term linkages between carbon price and influence factors considering COVID-19 impact. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:61479-61495. [PMID: 35396678 PMCID: PMC8993040 DOI: 10.1007/s11356-022-19858-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 03/18/2022] [Indexed: 05/10/2023]
Abstract
Because of global lock-downs caused by the unexpected COVID-19, the interactions between emission trading and related markets have changed significantly compared to the pre-COVID-19 period. Considering the pandemic effect, this paper established an integrated system to identify the relationship trajectories between carbon trading market and impact factors. A noise-assisted multivariate empirical mode decomposition (N-A MEMD) method was utilized to simultaneously decompose the original multi-dimensional time series into intrinsic mode functions (IMFs), after which the Lempel-Ziv (LZ) complexity algorithm was applied to reconstruct the IMFs into high-frequency (HF), low-frequency (LF), and trend modules. Vector autoregression (VAR) and vector error correction (VEC) models were then used to systematically simulate the correlations. The time span was split into pre-COVID-19 and post-COVID-19 periods for comparison, and the mobility trends data during the outbreak period released by the Apple company was chosen to reflect the pandemic effects. The empirical analysis results revealed the energy prices, macroeconomic index, and exchange rate are the main external impact factors of carbon price in the short term. Summarizing from the cointegration models over the long term, the market stability reserve (MSR) mechanism was found to have ability on stabilizing the carbon price under the epidemic shock. Furthermore, the COVID-19 was found to complicate the relationships between carbon price and influence factors, which resulted in fluctuating markets.
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Affiliation(s)
- Zhibin Wu
- Business School, Sichuan University, Chengdu, 610065, China.
| | - Wen Zhang
- Business School, Sichuan University, Chengdu, 610065, China
- School of Computer Science, The University of Manchester, Manchester, M13 9PL, UK
| | - Xiaojun Zeng
- School of Computer Science, The University of Manchester, Manchester, M13 9PL, UK
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Strzelecki A. The Apple Mobility Trends Data in Human Mobility Patterns during Restrictions and Prediction of COVID-19: A Systematic Review and Meta-Analysis. Healthcare (Basel) 2022; 10:2425. [PMID: 36553949 PMCID: PMC9778143 DOI: 10.3390/healthcare10122425] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 11/24/2022] [Accepted: 11/29/2022] [Indexed: 12/03/2022] Open
Abstract
The objective of this systematic review with PRISMA guidelines is to discover how population movement information has epidemiological implications for the spread of COVID-19. In November 2022, the Web of Science and Scopus databases were searched for relevant reports for the review. The inclusion criteria are: (1) the study uses data from Apple Mobility Trends Reports, (2) the context of the study is about COVID-19 mobility patterns, and (3) the report is published in a peer-reviewed venue in the form of an article or conference paper in English. The review included 35 studies in the period of 2020-2022. The main strategy used for data extraction in this review is a matrix proposal to present each study from a perspective of research objective and outcome, study context, country, time span, and conducted research method. We conclude by pointing out that these data are not often used in studies and it is better to study a single country instead of doing multiple-country research. We propose topic classifications for the context of the studies as transmission rate, transport policy, air quality, re-increased activities, economic activities, and financial markets.
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Affiliation(s)
- Artur Strzelecki
- Department of Informatics, University of Economics in Katowice, 40-287 Katowice, Poland
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4
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Dada M, Popoola P, Mathe N, Adeosun S. Wear characteristics of laser-deposited AlCoCrCuFeNi high entropy alloy with finite element analysis. BENI-SUEF UNIVERSITY JOURNAL OF BASIC AND APPLIED SCIENCES 2022. [DOI: 10.1186/s43088-022-00307-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Wear is a destructive phenomenon and one of the principal causes of material failure in moving components during surface interaction while in service. AlCoCrCuFeNi high-entropy alloy with its many properties is a potential material for aero-engine applications attributed to its outstanding relatively lightweight, high strength, good thermal, oxidation, and corrosion resistance properties. Hence, the investigation into the tribological behaviour of AlCoCrCuFeNi high-entropy alloys is essential to reduce maintenance costs and prolong the service life of this advanced material for aerospace applications. Most AlCoCrCuFeNi high-entropy alloy compositions were fabricated via arc melting, which has been reported to have defects attributed to slow solidification, consequently reducing the mechanical properties of the alloy with limited reports on other fabrication methods. Therefore, there is a need for the use of advanced manufacturing techniques for fabricating these alloys to improve the tribological properties. In this study, AlCoCrCuFeNi high-entropy alloy was fabricated via laser metal deposition. The influence of the laser processing parameters, rapid solidification, and the applied load on the tribological properties of the as-built alloys under dry conditions has been studied for aerospace applications. The counter ball rolling friction analysis was also investigated using COMSOL Multiphysics.
Results
The results showed that at a high laser power of 1600 W and a scan speed of 12 mm/s, the lowest wear rates and highest hardness values were observed. The average coefficient of friction at room temperature was 0.1 and 0.3 at a speed of 21 m/s. The dominant wear mechanism at room temperature was abrasive wear as the wear rate increased linearly with an increase in load from 10 to 20 N. The scan speed had the most significant influence on the wear behaviour of the as-built high-entropy alloy attributed to the rapid rate of solidification which occurs at higher scan speeds.
Conclusions
The study examines the wear characteristics of high-entropy alloys fabricated via laser deposition technique in comparison with those fabricated via conventional routes. Although there were similarities in the phase structures of both techniques, the results showed that the wear resistance of the laser-deposited high-entropy alloy was comparatively higher than the same alloy prepared via conventional methods. Laser additive manufacturing was concluded to be a more successful method in fabricating high-entropy alloys.
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Shadi R, Fakharian A, Khaloozadeh H. Modeling and Analysis of COVID-19 Spread: The Impacts of Nonpharmaceutical Protocols. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2022; 2022:7706447. [PMID: 36092782 PMCID: PMC9462995 DOI: 10.1155/2022/7706447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 07/14/2022] [Accepted: 08/07/2022] [Indexed: 11/20/2022]
Abstract
In this study, the extended SEIR dynamical model is formulated to investigate the spread of coronavirus disease (COVID-19) via a special focus on contact with asymptomatic and self-isolated infected individuals. Furthermore, a mathematical analysis of the model, including positivity, boundedness, and local and global stability of the disease-free and endemic equilibrium points in terms of the basic reproduction number, is presented. The sensitivity analysis indicates that reducing the disease contact rate and the transmissibility factor related to asymptomatic individuals, along with increasing the quarantine/self-isolation rate and the contact-tracing process, from the view of flattening the curve for novel coronavirus, are crucial to the reduction in disease-related deaths.
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Affiliation(s)
- Reza Shadi
- Department of Electrical Engineering, Qazvin Branch, Islamic Azad University, Qazvin, Iran
| | - Ahmad Fakharian
- Department of Electrical Engineering, Qazvin Branch, Islamic Azad University, Qazvin, Iran
| | - Hamid Khaloozadeh
- Department of Systems and Control Engineering, K.N. Toosi University of Technology, Tehran, Iran
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Hamed AM. Modeling of corona virus and its application in confocal microscopy. BENI-SUEF UNIVERSITY JOURNAL OF BASIC AND APPLIED SCIENCES 2022; 11:98. [PMID: 35992223 PMCID: PMC9375097 DOI: 10.1186/s43088-022-00276-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 07/25/2022] [Indexed: 11/30/2022] Open
Abstract
Background The proposal of spiky apertures showed resolution improvement compared with the circular apertures. Three models of corona virus are given. The 1st model consists of uniform circular aperture provided with 8 spikes while the 2nd model has 16 spikes for the same uniform circular aperture. The 3rd model has circular linear distribution with 8 spikes. Results The Normalized Point Spread Function (PSF) or the impulse response is computed for the three models using fast Fourier transform technique. In addition, the autocorrelation function corresponding to these apertures is calculated and compared with that corresponding to the ordinary circular and conic apertures. Coronavirus image is used as an object in the formation of images using confocal scanning laser microscope provided with suggested models. The fabricated MATLAB code is used to compute and plot all images and line plots. Conclusions The PSF plots are computed from Eqs. (8) and (12) using MATLAB code showing narrower cutoff in the PSF for spiky aperture compared with that corresponding to the uniform circular aperture and modulated linear and quadratic apertures. Hence, I reached resolution improvement in the case of spiky aperture.
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Sabbar Y, Kiouach D, Rajasekar SP. Acute threshold dynamics of an epidemic system with quarantine strategy driven by correlated white noises and Lévy jumps associated with infinite measure. INTERNATIONAL JOURNAL OF DYNAMICS AND CONTROL 2022; 11:122-135. [PMID: 35756149 PMCID: PMC9213645 DOI: 10.1007/s40435-022-00981-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 05/11/2022] [Accepted: 05/16/2022] [Indexed: 01/27/2023]
Abstract
Several studies have previously been conducted on the dynamics of probabilistic epidemic models driven by Lévy disorder. All of these works have used the Poisson counting process with finite Lévy measures. However, this scope disregards a considerable category of correlated Lévy jump processes governed by an infinite Lévy measure. In this research, we take into consideration this general framework applied to an epidemic model with a quarantine strategy. Under an appropriate hypothetical setting, we infer the exact threshold value between the ergodicity and the disease disappearance. Our analysis completes the work presented by Privault and Wang (J Nonlinear Sci 31(1):1-28, 2021) and puts forward a novel analytical aspect to deal with other stochastic models in several areas. As a numerical application, we implement the algorithm of Rosinski (Stoch Process Appl 117:677-707, 2007) for tempered stable Lévy processes with an infinite Lévy measure.
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Affiliation(s)
- Yassine Sabbar
- LPAIS Laboratory, Faculty of Sciences Dhar El Mahraz, Sidi Mohamed Ben Abdellah University, Fez, Morocco
| | - Driss Kiouach
- LPAIS Laboratory, Faculty of Sciences Dhar El Mahraz, Sidi Mohamed Ben Abdellah University, Fez, Morocco
| | - S. P. Rajasekar
- Department of Mathematics, Government Arts College for Women, Nilakottai, Tamilnadu 624202 India
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Sabbar Y, Kiouach D, Rajasekar SP, El-Idrissi SEA. The influence of quadratic Lévy noise on the dynamic of an SIC contagious illness model: New framework, critical comparison and an application to COVID-19 (SARS-CoV-2) case. CHAOS, SOLITONS, AND FRACTALS 2022; 159:112110. [PMID: 35502416 PMCID: PMC9035369 DOI: 10.1016/j.chaos.2022.112110] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 04/08/2022] [Accepted: 04/10/2022] [Indexed: 06/14/2023]
Abstract
This study concentrates on the analysis of a stochastic SIC epidemic system with an enhanced and general perturbation. Given the intricacy of some impulses caused by external disturbances, we integrate the quadratic Lévy noise into our model. We assort the long-run behavior of a perturbed SIC epidemic model presented in the form of a system of stochastic differential equations driven by second-order jumps. By ameliorating the hypotheses and using some new analytical techniques, we find the exact threshold value between extinction and ergodicity (persistence) of our system. The idea and analysis used in this paper generalize the work of N. T. Dieu et al. (2020), and offer an innovative approach to dealing with other random population models. Comparing our results with those of previous studies reveals that quadratic jump-diffusion has no impact on the threshold value, but it remarkably influences the dynamics of the infection and may worsen the pandemic situation. In order to illustrate this comparison and confirm our analysis, we perform numerical simulations with some real data of COVID-19 in Morocco. Furthermore, we arrive at the following results: (i) the time average of the different classes depends on the intensity of the noise (ii) the quadratic noise has a negative effect on disease duration (iii) the stationary density function of the population abruptly changes its shape at some values of the noise intensity. Mathematics Subject Classification 2020: 34A26; 34A12; 92D30; 37C10; 60H30; 60H10.
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Affiliation(s)
- Yassine Sabbar
- LPAIS Laboratory, Faculty of Sciences Dhar El Mahraz, Sidi Mohamed Ben Abdellah University, Fez, Morocco
| | - Driss Kiouach
- LPAIS Laboratory, Faculty of Sciences Dhar El Mahraz, Sidi Mohamed Ben Abdellah University, Fez, Morocco
| | - S P Rajasekar
- Department of Mathematics, Government Arts College for Women, Nilakottai 624202, Tamilnadu, India
| | - Salim El Azami El-Idrissi
- LPAIS Laboratory, Faculty of Sciences Dhar El Mahraz, Sidi Mohamed Ben Abdellah University, Fez, Morocco
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Mezouaghi A, Djillali S, Zeb A, Nisar KS. Global proprieties of a delayed epidemic model with partial susceptible protection. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2022; 19:209-224. [PMID: 34902988 DOI: 10.3934/mbe.2022011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
In the case of an epidemic, the government (or population itself) can use protection for reducing the epidemic. This research investigates the global dynamics of a delayed epidemic model with partial susceptible protection. A threshold dynamics is obtained in terms of the basic reproduction number, where for R0<1 the infection will extinct from the population. But, for R0>1 it has been shown that the disease will persist, and the unique positive equilibrium is globally asymptotically stable. The principal purpose of this research is to determine a relation between the isolation rate and the basic reproduction number in such a way we can eliminate the infection from the population. Moreover, we will determine the minimal protection force to eliminate the infection for the population. A comparative analysis with the classical SIR model is provided. The results are supported by some numerical illustrations with their epidemiological relevance.
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Affiliation(s)
- Abdelheq Mezouaghi
- Laboratory of Pure and Applied Mathematics, University of Mostaganem, Mostaganem, Algeria
- Faculty of Exact Sciences and Informatics, Mathematics Department, Hassiba Benbouali university, Chlef, Algeria
| | - Salih Djillali
- Faculty of Exact Sciences and Informatics, Mathematics Department, Hassiba Benbouali university, Chlef, Algeria
- Laboratoire d' Analyse Non Line' aire et Mathe' matiques Appliqu'es, University of Tlemcen, Tlemcen, Algeria
| | - Anwar Zeb
- Department of Mathematics, COMSATS University Islamabad, Abbottabad, 22060, Khyber Pakhtunkhwa, Pakistan
| | - Kottakkaran Sooppy Nisar
- Department of Mathematics, College of Arts and Science, Prince Sattam bin Abdulaziz University, Wadi Aldawaser, 11991, Saudi Arabia
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10
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Kiouach D, Sabbar Y. The long-time behavior of a stochastic SIR epidemic model with distributed delay and multidimensional Lévy jumps. INT J BIOMATH 2021. [DOI: 10.1142/s1793524522500048] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This paper reports novel theoretical and analytical results for a perturbed version of a SIR model with Gamma-distributed delay. Notably, our epidemic model is represented by Itô–Lévy stochastic differential equations in order to simulate sudden and unexpected external phenomena. By using some new and ameliorated mathematical approaches, we study the long-run characteristics of the perturbed delayed model. Within this scope, we give sufficient conditions for two interesting asymptotic properties: extinction and persistence of the epidemic. One of the most interesting results is that the dynamics of the stochastic model are closely related to the intensities of white noises and Lévy jumps, which can give us a good insight into the evolution of the epidemic in some unexpected situations. Our work complements the results of some previous investigations and provides a new approach to predict and analyze the dynamic behavior of epidemics with distributed delay. For illustrative purposes, numerical examples are presented for checking the theoretical study.
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Affiliation(s)
- Driss Kiouach
- LPAIS Laboratory, Faculty of Sciences Dhar El Mahraz, Sidi Mohamed Ben Abdellah University, Fez, Morocco
| | - Yassine Sabbar
- LPAIS Laboratory, Faculty of Sciences Dhar El Mahraz, Sidi Mohamed Ben Abdellah University, Fez, Morocco
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Abstract
In this work, we present the analysis of a mixed weighted fractional Brownian motion, defined by ηt:=Bt+ξt, where B is a Brownian motion and ξ is an independent weighted fractional Brownian motion. We also consider the parameter estimation problem for the drift parameter θ>0 in the mixed weighted fractional Ornstein–Uhlenbeck model of the form X0=0;Xt=θXtdt+dηt. Moreover, a simulation is given of sample paths of the mixed weighted fractional Ornstein–Uhlenbeck process.
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12
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Bouba Y, Tsinda EK, Fonkou MDM, Mmbando GS, Bragazzi NL, Kong JD. The Determinants of the Low COVID-19 Transmission and Mortality Rates in Africa: A Cross-Country Analysis. Front Public Health 2021; 9:751197. [PMID: 34746085 PMCID: PMC8568130 DOI: 10.3389/fpubh.2021.751197] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 09/14/2021] [Indexed: 01/08/2023] Open
Abstract
Background: More than 1 year after the beginning of the international spread of coronavirus 2019 (COVID-19), the reasons explaining its apparently lower reported burden in Africa are still to be fully elucidated. Few studies previously investigated the potential reasons explaining this epidemiological observation using data at the level of a few African countries. However, an updated analysis considering the various epidemiological waves and variables across an array of categories, with a focus on African countries might help to better understand the COVID-19 pandemic on the continent. Thus, we investigated the potential reasons for the persistently lower transmission and mortality rates of COVID-19 in Africa. Methods: Data were collected from publicly available and well-known online sources. The cumulative numbers of COVID-19 cases and deaths per 1 million population reported by the African countries up to February 2021 were used to estimate the transmission and mortality rates of COVID-19, respectively. The covariates were collected across several data sources: clinical/diseases data, health system performance, demographic parameters, economic indicators, climatic, pollution, and radiation variables, and use of social media. The collinearities were corrected using variance inflation factor (VIF) and selected variables were fitted to a multiple regression model using the R statistical package. Results: Our model (adjusted R-squared: 0.7) found that the number of COVID-19 tests per 1 million population, GINI index, global health security (GHS) index, and mean body mass index (BMI) were significantly associated (P < 0.05) with COVID-19 cases per 1 million population. No association was found between the median life expectancy, the proportion of the rural population, and Bacillus Calmette-Guérin (BCG) coverage rate. On the other hand, diabetes prevalence, number of nurses, and GHS index were found to be significantly associated with COVID-19 deaths per 1 million population (adjusted R-squared of 0.5). Moreover, the median life expectancy and lower respiratory infections rate showed a trend towards significance. No association was found with the BCG coverage or communicable disease burden. Conclusions: Low health system capacity, together with some clinical and socio-economic factors were the predictors of the reported burden of COVID-19 in Africa. Our results emphasize the need for Africa to strengthen its overall health system capacity to efficiently detect and respond to public health crises.
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Affiliation(s)
- Yagai Bouba
- Chantal BIYA International Reference Center for Research on HIV/AIDS Prevention and Management (CIRCB), Yaoundé, Cameroon
- Department of Experimental Medicine, University of Rome “Tor Vergata”, Rome, Italy
| | | | | | | | - Nicola Luigi Bragazzi
- Laboratory for Industrial and Applied Mathematics (LIAM), Department of Mathematics and Statistics, York University, Toronto, ON, Canada
- Africa-Canada Artificial Intelligence and Data Innovation Consortium (ACADIC), Department of Mathematics and Statistics, York University, Toronto, ON, Canada
| | - Jude Dzevela Kong
- Africa-Canada Artificial Intelligence and Data Innovation Consortium (ACADIC), Department of Mathematics and Statistics, York University, Toronto, ON, Canada
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El Bilali H, Ben Hassen T, Baya Chatti C, Abouabdillah A, Alaoui SB. Exploring Household Food Dynamics During the COVID-19 Pandemic in Morocco. Front Nutr 2021; 8:724803. [PMID: 34646850 PMCID: PMC8502820 DOI: 10.3389/fnut.2021.724803] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 08/31/2021] [Indexed: 12/23/2022] Open
Abstract
Alongside the dramatic impact on health systems, eating, shopping, and other food-related habits may have been affected by the COVID-19 crisis. This paper analyses the impacts of the COVID-19 pandemic on food shopping habits and food-related activities of a diverse sample of 340 adult consumers in Morocco. The study is based on an online survey conducted in Morocco from September 15 to November 5, 2020, utilizing a standardized questionnaire delivered in French and Arabic via Survey Monkey. The findings show that consumers' diet, shopping behavior, and food interactions have changed significantly. Indeed, the survey outcomes indicated (i) an increase in the consumption of local items owing to food safety concerns; (ii) an increase in online grocery shopping; (iii) a rise in panic buying and food hoarding; and (iv) an increase in culinary capabilities. The findings are expected to help guide Morocco's current emergency measures as well as long-term food-related policies.
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Affiliation(s)
- Hamid El Bilali
- International Centre for Advanced Mediterranean Agronomic Studies (CIHEAM-Bari), Valenzano, Italy
| | - Tarek Ben Hassen
- Department of International Affairs, College of Arts and Sciences, Qatar University, Doha, Qatar
| | - Chedli Baya Chatti
- Department of Social Sciences, College of Arts and Sciences, Qatar University, Doha, Qatar
| | - Aziz Abouabdillah
- Department of Agronomy and Plant Breeding, Ecole Nationale D'Agriculture de Meknès, Meknès, Morocco
| | - Si Bennasseur Alaoui
- Department of Production, Protection and Biotechnology, Institut Agronomique et Vétérinaire Hassan II, Rabat, Morocco
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Sitthiwirattham T, Zeb A, Chasreechai S, Eskandari Z, Tilioua M, Djilali S. Analysis of a discrete mathematical COVID-19 model. RESULTS IN PHYSICS 2021; 28:104668. [PMID: 34401224 PMCID: PMC8357495 DOI: 10.1016/j.rinp.2021.104668] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 08/05/2021] [Accepted: 08/05/2021] [Indexed: 05/04/2023]
Abstract
To describe the main propagation of the COVID-19 and has to find the control for the rapid spread of this viral disease in real life, in current manuscript a discrete form of the SEIR model is discussed. The main aim of this is to describe the viral disease in simplest way and the basic properties that are related with the nature of curves for susceptible and infected individuals are discussed here. The elementary numerical examples are given by using the real data of India and Algeria.
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Affiliation(s)
- Thanin Sitthiwirattham
- Mathematics Department, Faculty of Science and Technology, Suan Dusit University, Bangkok, Thailand
| | - Anwar Zeb
- Department of Mathematics, COMSATS University Islamabad, Abbottabad Campus, Abbottabad, 22060, Khyber Pakhtunkhwa, Pakistan
| | - Saowaluck Chasreechai
- Department of Mathematics, Faculty of Applied Science, King Mongkut's University of Technology North Bangkok, Bangkok, Thailand
| | - Zohreh Eskandari
- Department of Mathematical Sciences, Shahrekord University, Shahrekord, Iran
| | - Mouhcine Tilioua
- Department of Mathematics, MAMCS Group, FST Errachidia, Moulay Ismail University of Meknes, P.O. Box. 509 Boutalamine, 52000 Errachidia, Morocco
| | - Salih Djilali
- Laboratoire d'Analyse Non Linéaire et Mathématiques Appliquées, Université de Tlemcen, Tlemcen, Algeria
- Department of Mathematics, Faculty of Exact Sciences and Computer Science, Hassiba Benbouali University, Chlef, Algeria
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Bentout S, Djilali S, Kumar S, Touaoula TM. Threshold dynamics of difference equations for SEIR model with nonlinear incidence function and infinite delay. EUROPEAN PHYSICAL JOURNAL PLUS 2021; 136:587. [PMID: 34075326 PMCID: PMC8159023 DOI: 10.1140/epjp/s13360-021-01466-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 04/19/2021] [Indexed: 06/12/2023]
Abstract
In this research, we explore the global conduct of age-structured SEIR system with nonlinear incidence functional (NIF), where a threshold behavior is obtained. More precisely, we will analyze the investigated model differently, where we will rewrite it as a difference equations with infinite delay by the help of the characteristic method. Using standard conditions on the nonlinear incidence functional that can fit with a vast class of a well-known incidence functionals, we investigated the global asymptotic stability (GAS) of the disease-free equilibrium (DFE) using a Lyapunov functional (LF) for R 0 ≤ 1 . The total trajectory method is utilized for avoiding proving the local behavior of equilibria. Further, in the case R 0 > 1 we achieved the persistence of the infection and the GAS of the endemic equilibrium state (EE) using the weakly ρ -persistence theory, where a proper LF is obtained. The achieved results are checked numerically using graphical representations.
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Affiliation(s)
- Soufiane Bentout
- Laboratoire d’Analyse Non Linéaire et Mathématiques Appliquées, Université de Tlemcen, Tlemcen, Algeria
- Department of Mathematics and Informatics, Belhadj Bouchaib University of Ain Temouchent, BP 284 RP, 46000 Ain Temouchent, Algeria
| | - Salih Djilali
- Laboratoire d’Analyse Non Linéaire et Mathématiques Appliquées, Université de Tlemcen, Tlemcen, Algeria
- Faculty of Exact and Computer Sciences, Mathematic Department, Hassiba Benbouali university, Chlef, Algeria
| | - Sunil Kumar
- Department of Mathematics, National Institute of Technology Jamshedpur, Jharkhand, 831014 India
- Nonlinear Dynamics Research Center (NDRC), Ajman University, Ajman, UAE
| | - Tarik Mohammed Touaoula
- Laboratoire d’Analyse Non Linéaire et Mathématiques Appliquées, Université de Tlemcen, Tlemcen, Algeria
- Department of Mathematics, University of Tlemcen, 13000 Tlemcen, Algeria
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