27,343 research outputs found
Opinion formation about childhood immunization and disease spread on networks
People are physically and socially connected with each other. Those connections between people represent two, probably overlapping, networks: biological networks, through which physical contacts occur, or social network, through which information diffuse. In my thesis research, I am trying to answer that question in the context of pediatric disease spread on the biological network between households as well as within them and its relationship with information sharing on the social network of households (parents in that case) via Information Cascades. I mainly focus on the Erdos-Renyi network model. In particular, I use two different but overlapping Erdos-Renyi networks for the biological and social networks in the model. I am using agent-based stochastic simulations implemented in MatLab to study the modeling results
Adaptive Network Dynamics and Evolution of Leadership in Collective Migration
The evolution of leadership in migratory populations depends not only on
costs and benefits of leadership investments but also on the opportunities for
individuals to rely on cues from others through social interactions. We derive
an analytically tractable adaptive dynamic network model of collective
migration with fast timescale migration dynamics and slow timescale adaptive
dynamics of individual leadership investment and social interaction. For large
populations, our analysis of bifurcations with respect to investment cost
explains the observed hysteretic effect associated with recovery of migration
in fragmented environments. Further, we show a minimum connectivity threshold
above which there is evolutionary branching into leader and follower
populations. For small populations, we show how the topology of the underlying
social interaction network influences the emergence and location of leaders in
the adaptive system. Our model and analysis can describe other adaptive network
dynamics involving collective tracking or collective learning of a noisy,
unknown signal, and likewise can inform the design of robotic networks where
agents use decentralized strategies that balance direct environmental
measurements with agent interactions.Comment: Submitted to Physica D: Nonlinear Phenomen
Combination interventions for Hepatitis C and Cirrhosis reduction among people who inject drugs: An agent-based, networked population simulation experiment
Hepatitis C virus (HCV) infection is endemic in people who inject drugs
(PWID), with prevalence estimates above 60 percent for PWID in the United
States. Previous modeling studies suggest that direct acting antiviral (DAA)
treatment can lower overall prevalence in this population, but treatment is
often delayed until the onset of advanced liver disease (fibrosis stage 3 or
later) due to cost. Lower cost interventions featuring syringe access (SA) and
medically assisted treatment (MAT) for addiction are known to be less costly,
but have shown mixed results in lowering HCV rates below current levels. Little
is known about the potential synergistic effects of combining DAA and MAT
treatment, and large-scale tests of combined interventions are rare. While
simulation experiments can reveal likely long-term effects, most prior
simulations have been performed on closed populations of model agents--a
scenario quite different from the open, mobile populations known to most health
agencies. This paper uses data from the Centers for Disease Control's National
HIV Behavioral Surveillance project, IDU round 3, collected in New York City in
2012 by the New York City Department of Health and Mental Hygiene to
parameterize simulations of open populations. Our results show that, in an open
population, SA/MAT by itself has only small effects on HCV prevalence, while
DAA treatment by itself can significantly lower both HCV and HCV-related
advanced liver disease prevalence. More importantly, the simulation experiments
suggest that cost effective synergistic combinations of the two strategies can
dramatically reduce HCV incidence. We conclude that adopting SA/MAT
implementations alongside DAA interventions can play a critical role in
reducing the long-term consequences of ongoing infection
- …