Epidemics

2018 ◽  
pp. 120-148
Author(s):  
Ricard Solé ◽  
Santiago F. Elena
Keyword(s):  
Easter Island ◽  
Indigenous Australians ◽  
Human Populations ◽  
Human History ◽  
Epidemic Modeling ◽  
Sis Model ◽  
Scale Free ◽  
Scale Free Networks ◽  
Hiv 1

It has been argued that epidemics have played a major role in human history. For example, the arrival of the British in Australia triggered a deadly wave of smallpox infections, with the estimated death of half of the indigenous Australians. The same virus wiped out the population of Easter Island, and measles eliminated a third of the inhabitants of Fiji. New threats have also emerged as human populations explode and pressure on ecosystems crosses sustainability thresholds. In order to understand how to deal with epidemics and eradicate them, there is a need to first understand how they spread. This chapter begins with a discussion of epidemic modeling, specifically the SIS model. It then covers the SIS model in space and graphs, modeling HIV-1 transmission, and halting viruses in scale-free networks.

scholarly journals GEOGRAPHICAL EFFECTS ON EPIDEMIC SPREADING IN SCALE-FREE NETWORKS

2006 ◽  
Vol 17 (12) ◽  
pp. 1815-1822 ◽  
Author(s):  
XIN-JIAN XU ◽  
WEN-XU WANG ◽  
TAO ZHOU ◽  
GUANRONG CHEN
Keyword(s):  
Metric Space ◽  
Healthy Individual ◽  
Euclidean Distance ◽  
Nearest Neighbors ◽  
Epidemic Spreading ◽  
Sis Model ◽  
Scale Free ◽  
Scale Free Networks ◽  
Disease Spreading

Many real networks are embedded in a metric space: the interactions among individuals depend on their spatial distances and usually take place among their nearest neighbors. In this paper, we introduce a modified susceptible-infected-susceptible (SIS) model to study geographical effects on the spread of diseases by assuming that the probability of a healthy individual infected by an infectious one is inversely proportional to the Euclidean distance between them. It is found that geography plays a more important role than hubs in disease spreading: the more geographically constrained the network is, the more highly the epidemic prevails.

scholarly journals Dynamics analysis of an online gambling spreading model on scale-free networks

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Yu Kong ◽  
Tao Li ◽  
Yuanmei Wang ◽  
Xinming Cheng ◽  
He Wang ◽  
...  
Keyword(s):  
Network Topology ◽  
Negative Impact ◽  
Online Gambling ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Scale Free ◽  
Spreading Model ◽  
Spreading Dynamics ◽  
Scale Free Networks ◽  
Gambling Policy

AbstractNowadays, online gambling has a great negative impact on the society. In order to study the effect of people’s psychological factors, anti-gambling policy, and social network topology on online gambling dynamics, a new SHGD (susceptible–hesitator–gambler–disclaimer) online gambling spreading model is proposed on scale-free networks. The spreading dynamics of online gambling is studied. The basic reproductive number $R_{0}$ R 0 is got and analyzed. The basic reproductive number $R_{0}$ R 0 is related to anti-gambling policy and the network topology. Then, gambling-free equilibrium $E_{0}$ E 0 and gambling-prevailing equilibrium $E_{ +} $ E + are obtained. The global stability of $E_{0}$ E 0 is analyzed. The global attractivity of $E_{ +} $ E + and the persistence of online gambling phenomenon are studied. Finally, the theoretical results are verified by some simulations.

scholarly journals Effective gravitation path routing strategy on scale-free networks

IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Jinlong Ma ◽  
Junfeng Zhang ◽  
Yongqiang Zhang
Keyword(s):  
Scale Free ◽  
Routing Strategy ◽  
Scale Free Networks

scholarly journals Thermal Imaging Shows Submarine Groundwater Discharge Plumes Associated with Ancient Settlements on Rapa Nui (Easter Island, Chile)

2021 ◽  
Vol 13 (13) ◽  
pp. 2531
Author(s):  
Robert J. DiNapoli ◽  
Carl P. Lipo ◽  
Timothy S. de Smet ◽  
Terry L. Hunt
Keyword(s):  
Fresh Water ◽  
Submarine Groundwater Discharge ◽  
Groundwater Discharge ◽  
Water Sources ◽  
Easter Island ◽  
Human Populations ◽  
Rapa Nui ◽  
Hydrologic Processes ◽  
Submarine Groundwater ◽  
Aerial Systems

Submarine groundwater discharge (SGD) is an important component of many coastal environments and hydrologic processes, providing sources of nutrients to marine ecosystems, and potentially, an important source of fresh water for human populations. Here, we use a combination of unpiloted aerial systems (UAS) thermal infrared (TIR) imaging and salinity measurements to characterize SGD on the remote East Polynesian island of Rapa Nui (Easter Island, Chile). Previous research has shown that coastal freshwater seeps are abundant on Rapa Nui and strongly associated with the locations of ancient settlement sites. We currently lack, however, information on the differential magnitude or quality of these sources of fresh water. Our UAS-based TIR results from four locations on Rapa Nui suggest that locations of variably-sized SGD plumes are associated with many ancient settlement sites on the island and that these water sources are resilient to drought events. These findings support previous work indicating that ancient Rapa Nui communities responded to the inherent and climate-induced hydrological challenges of the island by focusing on these abundant and resilient freshwater sources. Our results highlight the efficacy of using UAS-based TIR for detecting relatively small SGD locations and provide key insights on the potential uses of these water sources for past and current Rapa Nui communities.

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