Research

The problem addressed in this paper – the role of mobility restrictions in the control of infectious diseases in neighboring communities – is raised in the most acute way by the imposition of area quarantines or cordons sanitaires. Specifically, we consider when mobility restrictions between two neighboring communities increase the final overall epidemic size, and when they do not.

We study the average number of infectionst hat descend down the chains of infection begun by each of the individuals infected in an outbreak (we refer to this quantity as the “average number ofdescendant infections” per infectious individual, or ANDI). ANDI includes not only the number of people that an individual directly contacts and infects, but also the number of people that those go on to infect, and so on until that par-ticular chain of infection dies out.

The role of official social network perturbations generated by public health officials to slow down or to stop a disease outbreak are studied over distinct classes of static social networks. The dynamics are stochastic in nature with individuals (nodes) being assigned fixed levels of education or wealth. Nodes may change their epidemiological status from susceptible, to infected and to recovered.

To evaluate the effectiveness of cordons sanitaires - mandatory movement restrictions between communities - we formulate a two-patch mathematical model for Ebola Virus Disease dynamics. Severe movement restrictions between high- and low-risk areas of closely linked communities may have a deleterious impact on the overall levels of infection in the total population.

The impact that effective population size and the distribution of individuals’ residence times in different patches have on TB transmission and control are studied using selected scenarios where risk is defined by the estimated or perceive first time infection and/or exogenous re-infection rates. The study identifies critical social behaviors mechanisms that can facilitate or eliminate TB infection in vulnerable populations.

We explore the role of mobility within communities characterized by extreme poverty, crime and violence. Specifically, the role of short term mobility between two idealized interconnected highly distinct communities is explored in the context of Zika Virus (ZIKV) outbreaks. It quickly became evident that matching observed patterns of ZIKV outbreaks could not be captured without incorporating increasing levels of heterogeneity.

Use of trending Internet searches and tweets has been proposed in the past for real-time prediction of outbreaks (a field referred to as “digital epidemiology”). We examine daily Ebola-related Internet search and Twitter data in the U. S. during the six week period ending Oct 31, 2014. TV news coverage data were obtained from the daily number of Ebola-related news videos appearing on two major news networks. We find significant evidence of contagion, with each Ebola-related news video inspiring tens of thousands of Ebola-related tweets and Internet searches.

We determine the safe operating space for the proportion of eggs that become male at which the population of Green sea turtle can exist without going to extinction.

Data from resources such as the International Search and Rescue Incident Database are analyzed to identify patterns in human behaviors and key geographic influences to develop a mechanistic model of missing persons. We use a discrete-time Markov Decision Process, where the lost individual’s state is used to determine a personal strategy for being found.

We developed and analyzed a data-driven mathematical model that captures the dynamics of prisoners while in and out of prison based on their education status. We study the economic impact of implementing transition programs. We found that some transition programs would eventually pay for themselves as a higher proportion of inmates enroll in the program.

The subject of this research is the method of "search and isolation" which seeks to isolate MRSA positive patients in a hospital so as to decrease infection potential. Although this strategy of search and isolate is straightforward, the question of just whom to screen is of practical importance. We compare screening at admission to screening at discharge

We develop and analyze a mathematical model that considers spread of Herpes Simplex Virus type 2 (HSV-2) among the population between the ages of 15-49 in the US and used it to design an optimal treatment distribution strategy. By considering the proposed strategy for treatment and comparing it with the conventional treatment, it can be observed that early treatment reduces HSV–2 incidence by 38% yearly.

Infections caused by antibiotic–resistant bacteria are posed to be one of the most pressing health concerns of the twenty–first century. A common mechanism of resistance involves production of an antibiotic–degrading enzyme. In this case, neighboring, nonproducer bacteria can “cheat” by sharing the benefits of resistance while the metabolic cost of enzyme production falls solely on producer cells. The objective of this work is to explore how the spatial population dynamics of producers and nonproducer maintain the resistance found in biofilms

Mass gatherings such as sporting events typically increase sexual activity and the spread of sexually transmitted diseases. We investigate three male-seeking-male (MSM) subpopulations: male natives in Rio, male visitors from outside of Rio, and male sex workers in Rio. We calculated basic reproductive numbers for specific preference scenarios.

We propose a mechanism to explain neuronal aging by tracking the number of non-transient DNA double-strand breaks (DSBs) and repairs over time that may lead to apoptosis. We derive three models to track the effect of neurodegeneration, using these models, we estimate a distribution for the lifespan of a neuron and explore the effect of parameters on time to death. We identify three possible causes of premature neuronal apoptosis: problems with coding critical repair proteins, issues with the neuron detecting DSBs, and issues with the neuron responding to DSBs.