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The forecasting of the nature and dynamics of emerging coronavirus (COVID-19) pandemic has gained a great concern for health care organizations and governments. The efforts aim to to suppress the rapid and global spread of its tentacles and also control the infection with the limited available resources. The aim of this work is to employ real data set to propose and analyze a compartmental discrete time COVID-19 pandemic model with non-linear incidence and hence predict and control its outbreak through dynamical research. The Basic Reproduction Number ( R 0 ) is calculated analytically to study the disease-free steady state ( R 0 < 1 ), and also the permanency case ( R 0 > 1 ) of the disease. Numerical results show that the transmission rates α > 0 and β > 0 are quite effective in reducing the COVID-19 infections in India or any country. The fitting and predictive capability of the proposed discrete-time system are presented for relishing the effect of disease through stability analysis using real data sets. [ABSTRACT FROM AUTHOR]

This paper is devoted to answering some questions using a mathematical model by analyzing India's first and second phases of the COVID-19 pandemic. A new mathematical model is introduced with a nonmonotonic incidence rate to incorporate the psychological effect of COVID-19 in society. The paper also discusses the local stability and global stability of an endemic equilibrium and a disease-free equilibrium. The basic reproduction number is evaluated using the proposed COVID-19 model for disease spread in India based on the actual data sets. The study of nonperiodic solutions at a positive equilibrium point is also analyzed. The model is rigorously studied using MATLAB to alert the decision-making bodies to hinder the emergence of any other pandemic outbreaks or the arrival of subsequent pandemic waves. This paper shows the excellent prediction of the first wave and very commanding for the second wave. The exciting results of the paper are as follows: (i) psychological effect on the human population has an impact on propagation; (ii) lockdown is a suitable technique mathematically to control the COVID spread; (iii) different variants produce different waves; (iv) the peak value always crosses its past value. [ABSTRACT FROM AUTHOR]

The objective of this paper is to study the dynamical properties of a discrete-time prey–predator model under imprecise biological parameters. We consider refuge for prey species as a constant number. The equilibria of the model are obtained, and the dynamic behaviors of the proposed system are examined for the interval biological parameters. Simulations of the model are performed for different parameters of the model. Numerical simulations demonstrate that the proposed discrete model exhibits rich dynamics of a chaotic and complex nature. [ABSTRACT FROM AUTHOR]

The paper investigates the dynamical behaviors of a two-species discrete predator-prey system with Crowley–Martin functional response incorporating prey refuge proportional to prey density. The existence of equilibrium points, stability of three fixed points, period-doubling bifurcation, Neimark–Sacker bifurcation, Marottos chaos, and Control Chaos are analyzed for the discrete-time domain. The time graphs, phase portraits, and bifurcation diagrams are obtained for different parameters of the model. Numerical simulations and graphics show that the discrete model exhibits rich dynamics, which also present that the system is a chaotic and complex one. This paper attempts to present a feedback control method which can stabilize chaotic orbits at an unstable equilibrium point. [ABSTRACT FROM AUTHOR]

In this study, a mathematical Omicron model has been studied in view of the densities of a susceptible population without a vaccine, with the first dose of vaccine, with the second dose of vaccine and with a booster dose of vaccine respectively, at the time t. The impact of the Omicron variant virus reservoir has been analysed. The basic reproduction number ( R 0 ) of the system at the disease-free equilibrium for all positive parameters has been discussed. An analysis of local and global stability under various conditions at disease-free and endemic equilibrium points has been conducted. The sensitivity analysis is performed and the most sensitive parameter of the system is identified. On the basis of the effect of various parameters on the system, we perform numerical simulation of the Omicron variant system in Indian population. [ABSTRACT FROM AUTHOR]

We investigate a discrete-time Chen system. First, we give the topological classifications of the fixed points of this system. Then, we analytically show that the discrete Chen system underlies a Neimark–Sacker (NS) bifurcation and period doubling (PD) under specific parametric circumstances. We confirm the existence of a PD and NS bifurcation via the explicit PD-NS bifurcation criterion and determine the direction of both bifurcations with the help of center manifold theory. We performed numerical simulations to confirm our analytical results. Furthermore, we use the 0-1 chaos test to quantify whether there is chaos in the system or not. At the end, the hybrid control strategy and the OGY (Ott, Grebogi, and Yorke) method are applied to eliminate chaotic trajectories of the system. [ABSTRACT FROM AUTHOR]

The study evaluates chemotherapeutic management of canine demodicosis in 96 dogs of different ages and sex. The dogs were treated with Benzoyl peroxide shampoo, inj. Ivermectin, Amitraz, antibiotic Cephalexin-600 and Multi Vitamin syrup one tsf BID for 28 days. Skin scrapings examination was undertaken in every weeks for four weeks. On 21st and 28th days, no adult or developmental stages of mite was found in skin scrapping examination and all dogs completely recovered. [ABSTRACT FROM AUTHOR]

7-Chloro-5-carbomethoxy-1,3-dihydro-2H-1,4-benzodiazepines and its nucleophilic substituted products were synthesized via η6-arenetricarbonylchromium(0) intermediates. Ring enlargement of 5-chloro-N-chloroacetylisatin with hexamine in presence of Cr(CO)6 led to the formation of 7-chloro-5-carbomethoxy-1,3-dihydro-2H-1,4-benzodiazepine in good yield with reduced reaction time. Nucleophilic substitutions on arene ring of η6-arenetricarbonylchromium(0) complexes with thiols, phenol, and primary amines were successfully carried out in decalin medium. [ABSTRACT FROM AUTHOR]

This paper presents the dispersal effect on a prey-predator model with three-patch states incorporating a strong Allee effect on the first two prey populations. The prey species are considered to be mutable to exhibit a balanced dispersal between the patches. The dispersal among patches is directed through lower fit patches to higher fit patches. This paper derives a new approach for dispersal and Allee's effect with the specific condition on the stability on a three-patch of a three-species prey-predator anticipated system. The persistence of the system is observed because of the dispersal effect on the three-patch prey-predator system. The numerical simulations of analytical findings are presented using hypothetical parameter values to relate real-world prey-predator situations for balancing ecology. [ABSTRACT FROM AUTHOR]

This paper presents the current situation and how to minimize its effect in India through a mathematical model of infectious Coronavirus disease (COVID-19). This model consists of six compartments to population classes consisting of susceptible, exposed, home quarantined, government quarantined, infected individuals in treatment, and recovered class. The basic reproduction number is calculated, and the stabilities of the proposed model at the disease-free equilibrium and endemic equilibrium are observed. The next crucial treatment control of the Covid-19 epidemic model is presented in India's situation. An objective function is considered by incorporating the optimal infected individuals and the cost of necessary treatment. Finally, optimal control is achieved that minimizes our anticipated objective function. Numerical observations are presented utilizing MATLAB software to demonstrate the consistency of present-day representation from a realistic standpoint. [ABSTRACT FROM AUTHOR]