80,282 research outputs found
Modeling TB-HIV syndemic and treatment
Tuberculosis (TB) and human immunodeficiency virus (HIV) can be considered a
deadly human syndemic. In this article, we formulate a model for TB and HIV
transmission dynamics. The model considers both TB and acquired immune
deficiency syndrome (AIDS) treatment for individuals with only one of the
infectious diseases or both. The basic reproduction number and equilibrium
points are determined and stability is analyzed. Through simulations, we show
that TB treatment for individuals with only TB infection reduces the number of
individuals that become co-infected with TB and HIV/AIDS, and reduces the
diseases (TB and AIDS) induced deaths. Analogously, the treatment of
individuals with only AIDS also reduces the number of co-infected individuals.
Further, TB-treatment for co-infected individuals in the active and latent
stage of TB disease, implies a decrease of the number of individuals that
passes from HIV-positive to AIDS.Comment: This is a preprint of a paper whose final and definite form is:
Journal of Applied Mathematics (ISSN 1110-757X) 2014, Article ID 248407,
http://dx.doi.org/10.1155/2014/24840
Domain wall description of superconductivity
In the present work we shall address the issue of electrical conductivity in
superconductors in the perspective of superconducting domain wall solutions in
the realm of field theory. We take our set up made out of a dynamical complex
scalar field coupled to gauge field to be responsible for superconductivity and
an extra scalar real field that plays the role of superconducting domain walls.
The temperature of the system is interpreted through the fact that the soliton
following accelerating orbits is a Rindler observer experiencing a thermal
bath.Comment: 9 pages, 5 figures, Latex. Version to appear in PL
Neutrinos and Electromagnetic Gauge Invariance
It is discussed a recently proposed connection among U(1)
electromagnetic gauge invariance and the nature of the neutrino mass terms in
the framework of \mbox {SU(3)}_C\otimes G_W \otimes {\mbox U(1)}_N, =
SU(3), extensions of the Standard Model. The impossibility of that
connection, also in the extended case = SU(4), is demonstrated.Comment: 10 pages, Revtex 3.0, no figure
Multiobjective optimization to a TB-HIV/AIDS coinfection optimal control problem
We consider a recent coinfection model for Tuberculosis (TB), Human
Immunodeficiency Virus (HIV) infection and Acquired Immunodeficiency Syndrome
(AIDS) proposed in [Discrete Contin. Dyn. Syst. 35 (2015), no. 9, 4639--4663].
We introduce and analyze a multiobjective formulation of an optimal control
problem, where the two conflicting objectives are: minimization of the number
of HIV infected individuals with AIDS clinical symptoms and coinfected with
AIDS and active TB; and costs related to prevention and treatment of HIV and/or
TB measures. The proposed approach eliminates some limitations of previous
works. The results of the numerical study provide comprehensive insights about
the optimal treatment policies and the population dynamics resulting from their
implementation. Some nonintuitive conclusions are drawn. Overall, the
simulation results demonstrate the usefulness and validity of the proposed
approach.Comment: This is a preprint of a paper whose final and definite form is with
'Computational and Applied Mathematics', ISSN 0101-8205 (print), ISSN
1807-0302 (electronic). Submitted 04-Feb-2016; revised 11-June-2016 and
02-Sept-2016; accepted for publication 15-March-201
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