Global asymptotic stability of constant equilibrium point in attraction-repulsion chemotaxis model with logistic source term

OMA-Vol. 6 (2022), Issue 2, pp. 102 – 119 Open Access Full-Text PDF
Abdelhakam Hassan Mohammed and Ali. B. B. Almurad

Abstract:This paper deals with nonnegative solutions of the Neumann initial-boundary value problem for an attraction-repulsion chemotaxis model with logistic source term of Eq. (1) in bounded convex domains \(\Omega\subset\mathbb{R}^{n},~ n\geq1\), with smooth boundary. It is shown that if the ratio \(\frac{\mu}{\chi \alpha-\xi \gamma}\) is sufficiently large, then the unique nontrivial spatially homogeneous equilibrium given by \((u_{1},u_{2},u_{3})=(1,~\frac{\alpha}{\beta},~\frac{\gamma}{\eta})\) is globally asymptotically stable in the sense that for any choice of suitably regular nonnegative initial data \((u_{10},u_{20},u_{30})\) such that \(u_{10}\not\equiv0\), the above problem possesses uniquely determined global classical solution \((u_{1},u_{2},u_{3})\) with \((u_{1},u_{2},u_{3})|_{t=0}=(u_{10},u_{20},u_{30})\) which satisfies \(\left\|u_{1}(\cdot,t)-1\right\|_{L^{\infty}(\Omega)}\rightarrow{0},~~
\left\|u_{2}(\cdot,t)-\frac{\alpha}{\beta}\right\|_{L^{\infty}(\Omega)}\rightarrow{0},\left\|u_{3}(\cdot,t)-\frac{\gamma}{\eta}\right\|_{L^{\infty}(\Omega)}\rightarrow{0}\,,\) \(\mathrm{as}~t\rightarrow{\infty}\).

Read more

Major bacteriological isolates and their antimicrobial susceptibility trends in ICU of a tertiary care hospital: A prospective observational study

TCMS-Vol. 2 (2022), Issue 4, pp. 1 – 7 Open Access Full-Text PDF
Kirti Ahuja, Prateek, Meena Singh, Anil Kumar Verma, Pranav Bansal and Sanjay.

Abstract:Bacterial bloodstream infections are important causes of morbidity and mortality, globally. The aim of the present study was to determine the bacterial profile of bloodstream infections and their antibiotic susceptibility pattern among the patients admitted to ICU at a tertiary care hospital.This prospective study was conducted over a period of eighteen months. Inclusion criteria comprised of patients admitted to ICU who belonged to either gender and were in the age group of 15-60 years. Over the course of study, 30 out of total 140 blood culture samples were identified to be culture positive (18 GNB and 11GPB). The most common Gram-positive isolate was Staphylococcus spp (26%) while Escherichia coli was the most common gram negative isolate (36%).Escherichia coli expressed highest resistance to all the drugs but sensitivity to Meropenemand Polymyxin B was 72% and 90%, respectively. High degree of resistance was noted to cephalosporins and piperacillin -tazobactam, among all the groups. The study indicated high level of antimicrobial resistance among Gram negative bacilli, esp E.Coli and justifies the need for antimicrobial stewardship to prevent development of further resistance.

Read more

Forecasting the democratic republic of the Congo macroeconomic data with the Bayesian vector autoregressive models

OMA-Vol. 6 (2022), Issue 2, pp. 93 – 101 Open Access Full-Text PDF
Lewis N. K. Mambo, Victor G. Musa and Gabriel M. Kalonda

Abstract:The purpose of this paper is to emphasize the role of the Bayesian Vector Autoregressive models (VAR) in macroeconomic analysis and forecasting. To help the policy-makers to do better, the Bayesian VAR models are considered more robust and valuable because they put in the model the mathematician’s beliefs or priors and the data. By using BVAR(1), we get the main results: (i)the best out sample point forecasts; (ii) the exchange rate shock contributes more to inflation; (iii) the inflation shock has high effects on exchange rate innovation. These results are due to the dollarization of this small open economy.

Read more

Estimation to the number of limit cycles for generalized Kukles differential system

OMA-Vol. 6 (2022), Issue 2, pp. 74 – 92 Open Access Full-Text PDF
Houdeifa Melki and Amar Makhlouf

Abstract:This article considers the limit cycles of a class of Kukles polynomial differential systems of the form Eq. (5). We obtain the maximum number of limit cycles that bifurcate from the periodic orbits of a linear center \(\dot{x}=y, \dot{y}=-x,\) by using the averaging theory of first and second order.

Read more

Solution of generalized Abel’s integral equation using orthogonal polynomials

OMA-Vol. 6 (2022), Issue 2, pp. 65 – 73 Open Access Full-Text PDF
Mamman Ojima John, Aboiyar Terhemen and Tivde Tertsegha

Abstract:This research presents the solution of the generalized version of Abel’s integral equation, which was computed considering the first and second kinds. First, Abel’s integral equation and its generalization were described using fractional calculus, and the properties of Orthogonal polynomials were also described. We then developed a technique of solution for the generalized Abel’s integral equation using infinite series of orthogonal polynomials and utilized the numerical method to approximate the generalized Abel’s integral equation of the first and second kind, respectively. The Riemann-Liouville fractional operator was used in these examples. Our technique was implemented in MAPLE 17 through some illustrative examples. Absolute errors were estimated. In addition, the occurred errors between using orthogonal polynomials for solving Abel’s integral equations of order \(0\ <\ \alpha \ <\ 1\) and the exact solutions show that the orthogonal polynomials used were highly effective, reliable and can be used independently in situations where the exact solution is unknown which the numerical experiments confirmed.

Read more

Stabilities of non-standard Euler-Maruyama scheme’s for Vasicek and geometric brownian motion models

OMA-Vol. 6 (2022), Issue 2, pp. 51 – 64 Open Access Full-Text PDF
Badibi O. Christopher, Ramadhani I., Ndondo M. Apollinaire and Kumwimba S. Didier

Abstract:Stochastic differential equations (SDEs) are a powerful tool for modeling certain random trajectories of diffusion phenomena in the physical, ecological, economic, and management sciences. However, except in some cases, it is generally impossible to find an explicit solution to these equations. In this case, the numerical approach is the only favorable possibility to find an approximative solution. In this paper, we present the mean and mean-square stability of the Non-standard Euler-Maruyama numerical scheme using the Vasicek and geometric Brownian motion models.

Read more

On a class of \(p\)-valent functions with negative coefficients defined by opoola differential operator

OMA-Vol. 6 (2022), Issue 2, pp. 35 – 50 Open Access Full-Text PDF
Bitrus Sambo and Timothy Oloyede Opoola

Abstract:Using opoola differential operator, we defined a subclass \(S^{n}_{p}(\lambda,\alpha,\gamma,\delta)\) of the class of multivalent or p-valent functions. Several properties of the class were studied, such as coefficient inequalities, hadamard product, radii of close-to-convex, star-likeness, convexity, extreme points, the integral mean inequalities for the fractional derivatives, and further growth and distortion theorem are given using fractional calculus techniques.

Read more

Results of semigroup of linear operators generating a nonlinear Schrödinger equation

OMA-Vol. 6 (2022), Issue 2, pp. 29 – 34 Open Access Full-Text PDF
J. B. Omosowon, A. Y. Akinyele and F. Y. Aderibigbe

Abstract:In this paper, we present results of \(\omega\)-order preserving partial contraction mapping generating a nonlinear Schr\”odinger equation. We used the theory of semigroup to generate a nonlinear Schr\(\ddot{o}\)dinger equation by considering a simple application of Lipschitz perturbation of linear evolution equations. We considered the space \(L^2(\mathbb{R}^2)\) and of linear operator \(A_0$ by $D(A_0)=H^2(\mathbb{R}^2)\) and \(A_0u=-i\Delta u\) for \(u\in D(A_0)\) for the initial value problem, we hereby established that \(A_0\) is the infinitesimal generator of a \(C_0\)-semigroup of unitary operators \(T(t)\), \(-\infty

Read more

On generalized Tetranacci numbers: Closed forms of the sum formulas \(\sum\limits_{k=0}^{n}kx^{k}W_{k}\) and \(\sum\limits_{k=1}^{n}kx^{k}W_{-k}\)

OMA-Vol. 6 (2022), Issue 2, pp. 1 – 28 Open Access Full-Text PDF
Yüksel Soykan, Erkan Taşdemir and Inci Okumuş

Abstract:In this paper, closed forms of the sum formulas \(\sum\limits_{k=0}^{n}kx^{k}W_{k}\) and \(\sum\limits_{k=1}^{n}kx^{k}W_{-k}\) for generalized Tetranacci numbers are presented. As special cases, we give summation formulas of Tetranacci, Tetranacci-Lucas, and other fourth-order recurrence sequences.

Read more

Compatible maps of type \((\beta)\) in intuitionistic generalized fuzzy metric spaces

ODAM-Vol. 5 (2022), Issue 3, pp. 1 – 12 Open Access Full-Text PDF
R. Pandiselvi, M. Jeyaraman and A. Ramachandran

Abstract: This paper presents several fixed point theorems for intuitionistic generalized fuzzy metric spaces with an implicit relation. Specifically, we utilize compatible maps of type \((\beta)\) in intuitionistic generalized fuzzy metric spaces to derive our fixed point theorems. Our results not only extend but also generalize some fixed point theorems that were previously established in complete fuzzy metric spaces. This is achieved by introducing a novel technique, which enhances the applicability and scope of the existing fixed point theorems.

Read more