Gabrick, Enrique C.Protachevicz, Paulo R.Batista, Antonio M.Iarosz, Kelly C....
12页查看更多>>摘要：In this work, to support decision making of immunisation strategies, we propose the inclusion of two vaccination doses in the SEIR model considering a stochastic cellular automaton. We analyse three different scenarios of vaccination: (i) unlimited doses, (ii) limited doses into susceptible individuals, and (iii) limited doses randomly distributed overall individuals. Our results suggest that the number of vaccinations and time to start the vaccination is more relevant than the vaccine efficacy, delay between the first and second doses, and delay between vaccinated groups. The scenario (i) shows that the solution can converge early to a disease-free equilibrium for a fraction of individuals vaccinated with the first dose. In the scenario (ii), few two vaccination doses divided into a small number of applications reduce the number of infected people more than into many applications. In addition, there is a low waste of doses for the first application and an increase of the waste in the second dose. The scenario (iii) presents an increase in the waste of doses from the first to second applications more than the scenario (ii). In the scenario (iii), the total of wasted doses increases linearly with the number of applications. Furthermore, the number of effective doses in the application of consecutive groups decays exponentially overtime. (C) 2022 Elsevier B.V. All rights reserved.
原文链接:
NSTL
Elsevier
Ding, L. J.Xiang, L.Zhong, Y.
10页查看更多>>摘要：We study the quantum phase transitions (QPTs) and quantum criticality of transverse field Ising model with off-diagonal exchange interactions. In the absence of magnetic field, the clockwise spiral (CWS), counterclockwise spiral (CCWS) and longitudinal ferromagnetic (xFM) phases are revealed by the spin chirality vector lcz and longitudinal spin-spin correlation C-xx mutually. The general QPT is diagnosed by the temperature power-law divergence of Gruneisen ratio (GR) F ~ +/- T-1. The critical scaling is further done to capture the quantum critical point (QCP) by analyzing lcz and specific heat, which offers a direct access to distill the critical exponents (delta, beta, alpha) that fulfill the Essam-Fisher relation alpha + beta(1 + delta)=2, providing a new clue to detect the general QPT. Subsequently, some scaling hypothesis equations are proposed to check the scaling analysis. In a magnetic field, an additional field-induced transverse ferromagnetic (zFM) phase is unveiled. Specifically, for the xFM phase transition into zFM one, the transverse field Ising terms predominates, which approximately keeps the Z(2) symmetry at h(c) = 1, giving rise to the self-dual quantum criticality, demonstrated by the constant of GR irrelevant of temperature. Furthermore, the gapped and gapless low-lying excitations of quantum phases are manifested by the thermal Drude weight and specific heat. (C) 2022 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Abidemi, AfeezOwolabi, Kolade M.Pindza, Edson
22页查看更多>>摘要：In this paper, a seven-dimensional nonlinear mathematical model featuring the vertical transmission in humans, saturated incidence functions, and human population with good and poor community hygiene is formulated to describe the dynamics of Lassa fever (LF) disease transmission between the interacting human and rodent populations. The model is analysed to investigate the dynamical behaviour of its solutions using some theories of dynamical system of ordinary differential equations. The basic reproduction number, R-0, of the model is established. A suitable Lyapunov function is constructed to establish the global asymptotic behaviour of the model about the Lassa fever-free equilibrium. Sensitivity analysis is carried out to gain insightful information about how R-0 is influenced by the variation in the model parameters. Numerical simulations are conducted to examine the effects of the most sensitive model parameters on the population dynamics of LF. The results obtained provide epidemiological insights into the impact of key model parameters on the transmission dynamics of LF and suggest some measures to fight or guide against the disease spread in a population. (C) 2022 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
