Citation: Al-Saidi, N.M.G.; Yahya, H.; Obaiys, S.J. Discrete Dynamic Model of a Disease-Causing Organism Caused by 2D-quantum Tsallis Entropy. Symmetry 2022, 14, 1677. https://doi.org/10.3390/ sym14081677 Academic Editor: Hüseyin Budak Received: 5 July 2022 Accepted: 8 August 2022 Published: 12 August 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). symmetry S S Article Discrete Dynamic Model of a Disease-Causing Organism Caused by 2D-Quantum Tsallis Entropy Nadia M. G. Al-Saidi 1 , Husam Yahya 2 and Suzan J. Obaiys 3, * 1 Department of Applied Sciences, University of Technology, Baghdad 10066, Iraq 2 Computer Engineering Techniques, Faculty of Information Technology, Imam Ja’afar Al-Sadiq University, Baghdad 10064, Iraq 3 Department of Computer Systems and Technology, Faculty of Computer Science and Information Technology, University Malaya, Kuala Lumpur 50603, Malaysia * Correspondence: suzan@um.edu.my Abstract: Many aspects of the asymmetric organ system are controlled by the symmetry model (R&L) of the disease-causing organism pathway, but sensitive matters like somites and limb buds need to be shielded from its influence. Because symmetric and asymmetric structures develop from similar or nearby matters and utilize many of the same signaling pathways, attaining symmetry is made more difficult. On this note, we aim to generalize some important measurements in view of the 2D-quantum calculus (q-calculus, q-analogues or q-disease), including the dimensional of fractals and Tsallis entropy (2D-quantum Tsallis entropy (2D-QTE)). The process is based on producing a generalization of the maximum value of the Tsallis entropy in view of the quantum calculus. Then by considering the maximum 2D-QTE, we design a discrete system. As an application, by using the 2D-QTE, we depict a discrete dynamic system that is afflicted with a disease-causing organism (DCO). We look at the system’s positive and maximum solutions. Studies are done on equilibrium and stability. We will also develop a novel design for the fundamental reproductive ratio based on the 2D-QTE. Keywords: quantum calculus; fractal; Tsallis entropy; discrete dynamic system; equilibrium point 1. Introduction The history of quantum calculus, often referred to as the q-derivative, Jackson deriva- tive, or q-disease, and dating back three centuries to the works of Bernoulli and Euler, is one of the most challenging math topics to grasp [1]. The q-derivative actions are now de- veloping swiftly due to their versatility in fields like mathematics, mechanics, and physics. Quantum mechanics, analytic number theory, special functions theory of finite differences, Bernoulli and Euler polynomials, combinatory, entropy definition, information theory, the theory of computer science, computational studies, image processing, chemical process- ing, data sciences, umbral derivative, Sobolev fractional norms, operator principle, and more recently, the idea of geometric functions theory, all benefit from the wide variety of applications of q-derivative (see [2–5]). For a very long time, discrete dynamic systems of DCO were the subject of intense discussion because they were successful at describing the process of disease dissemination (see [6]). The classic DCO was provided in the prior twenty centuries [7]. Following that, a huge number of publications on DCO [8–10] were established. Overall, DCOs are thought to be homogeneously mixed, which means that the same information is spread to those who are susceptible. However, there are several systems of populations in humanoid society, and linking between individuals is not always the same [11]. The fundamental reproductive ratio [12] is used to study the stability and convergence of the structures. Depending on the system and circumstances of the solution, this ratio is expressed in several formulas. We propose novel formalization of this ratio based on the entropy idea in our argument. Symmetry 2022, 14, 1677. https://doi.org/10.3390/sym14081677 https://www.mdpi.com/journal/symmetry