scholarly journals Social fluidity mobilizes contagion in human and animal populations

2017 ◽  
Author(s):  
Ewan Colman ◽  
Vittoria Colizza ◽  
Ephraim M. Hanks ◽  
David P. Hughes ◽  
Shweta Bansal
Keyword(s):  
Disease Transmission ◽  
Social Bonds ◽  
Group Living ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Animal Populations ◽  
Social Mixing ◽  
The Social ◽  
Group Members ◽  
Social Fluidity

Humans and other group-living animals tend to distribute their social effort disproportionately. Individuals predominantly interact with a small number of close companions while maintaining weaker social bonds with less familiar group members. By incorporating this behaviour into a mathematical model we find that a single parameter, which we refer to as social fluidity, controls the rate of social mixing within the group. We compare the social fluidity of 13 species by applying the model to empirical human and animal social interaction data. To investigate how social behavior influences the likelihood of an epidemic outbreak we derive an analytical expression of the relationship between social fluidity and the basic reproductive number of an infectious disease. For highly fluid social behaviour disease transmission is revealed to be density-dependent. For species that form more stable social bonds, the model describes frequency-dependent transmission that is sensitive to changes in social fluidity.

scholarly journals Social fluidity mobilizes contagion in human and animal populations

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Ewan Colman ◽  
Vittoria Colizza ◽  
Ephraim M Hanks ◽  
David P Hughes ◽  
Shweta Bansal
Keyword(s):  
Social Bonds ◽  
Group Living ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Frequency Dependent ◽  
Density Dependent ◽  
Gregarious Behavior ◽  
Animal Populations ◽  
Group Members ◽  
Social Fluidity

Humans and other group-living animals tend to distribute their social effort disproportionately. Individuals predominantly interact with a small number of close companions while maintaining weaker social bonds with less familiar group members. By incorporating this behavior into a mathematical model, we find that a single parameter, which we refer to as social fluidity, controls the rate of social mixing within the group. Large values of social fluidity correspond to gregarious behavior, whereas small values signify the existence of persistent bonds between individuals. We compare the social fluidity of 13 species by applying the model to empirical human and animal social interaction data. To investigate how social behavior influences the likelihood of an epidemic outbreak, we derive an analytical expression of the relationship between social fluidity and the basic reproductive number of an infectious disease. For species that form more stable social bonds, the model describes frequency-dependent transmission that is sensitive to changes in social fluidity. As social fluidity increases, animal-disease systems become increasingly density-dependent. Finally, we demonstrate that social fluidity is a stronger predictor of disease outcomes than both group size and connectivity, and it provides an integrated framework for both density-dependent and frequency-dependent transmission.

scholarly journals Rapid transmission of respiratory infections within but not between mountain gorilla groups

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Robin E. Morrison ◽  
Yvonne Mushimiyimana ◽  
Tara S. Stoinski ◽  
Winnie Eckardt
Keyword(s):  
Disease Transmission ◽  
Respiratory Infections ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Wild Populations ◽  
Gorilla Beringei Beringei ◽  
The Social ◽  
Gorilla Beringei ◽  
Rapid Transmission ◽  
Range Overlap

AbstractMinimizing disease transmission between humans and wild apes and controlling outbreaks in ape populations is vital to both ape conservation and human health, but information on the transmission of real infections in wild populations is rare. We analyzed respiratory outbreaks in a subpopulation of wild mountain gorillas (Gorilla beringei beringei) between 2004 and 2020. We investigated transmission within groups during 7 outbreaks using social networks based on contact and proximity, and transmission between groups during 15 outbreaks using inter-group encounters, transfers and home range overlap. Patterns of contact and proximity within groups were highly predictable based on gorillas’ age and sex. Disease transmission within groups was rapid with a median estimated basic reproductive number (R0) of 4.18 (min = 1.74, max = 9.42), and transmission was not predicted by the social network. Between groups, encounters and transfers did not appear to have enabled disease transmission and the overlap of groups’ ranges did not predict concurrent outbreaks. Our findings suggest that gorilla social structure, with many strong connections within groups and weak ties between groups, may enable rapid transmission within a group once an infection is present, but limit the transmission of infections between groups.

Modeling and stability analysis of the spread of novel coronavirus disease COVID-19

2021 ◽  
pp. 2150035
Author(s):  
A. George Maria Selvam ◽  
Jehad Alzabut ◽  
D. Abraham Vianny ◽  
Mary Jacintha ◽  
Fatma Bozkurt Yousef
Keyword(s):  
Fractional Order ◽  
Disease Transmission ◽  
Equilibrium Points ◽  
Sufficient Conditions ◽  
Basic Reproductive Number ◽  
Phase Portraits ◽  
Transmission Model ◽  
Reproductive Number ◽  
Discrete Version ◽  
Novel Coronavirus

Towards the end of 2019, the world witnessed the outbreak of Severe Acute Respiratory Syndrome Coronavirus-2 (COVID-19), a new strain of coronavirus that was unidentified in humans previously. In this paper, a new fractional-order Susceptible–Exposed–Infected–Hospitalized–Recovered (SEIHR) model is formulated for COVID-19, where the population is infected due to human transmission. The fractional-order discrete version of the model is obtained by the process of discretization and the basic reproductive number is calculated with the next-generation matrix approach. All equilibrium points related to the disease transmission model are then computed. Further, sufficient conditions to investigate all possible equilibria of the model are established in terms of the basic reproduction number (local stability) and are supported with time series, phase portraits and bifurcation diagrams. Finally, numerical simulations are provided to demonstrate the theoretical findings.

Social Networks and Social Complexity in Female-bonded Primates

2010 ◽  
Author(s):  
Julia Lehmann ◽  
Katherine Andrews ◽  
Robin Dunbar
Keyword(s):  
Social Network ◽  
Social Relationships ◽  
Social Complexity ◽  
Social Bonds ◽  
Primate Brain ◽  
The Social ◽  
Group Members ◽  
Primate Group ◽  
Network Metrics ◽  
The Relationship

Most primates are intensely social and spend a large amount of time servicing social relationships. The social brain hypothesis suggests that the evolution of the primate brain has been driven by the necessity of dealing with increased social complexity. This chapter uses social network analysis to analyse the relationship between primate group size, neocortex ratio and several social network metrics. Findings suggest that social complexity may derive from managing indirect social relationships, i.e. relationships in which a female is not directly involved, which may pose high cognitive demands on primates. The discussion notes that a large neocortex allows individuals to form intense social bonds with some group members while at the same time enabling them to manage and monitor less intense indirect relationships without frequent direct involvement with each individual of the social group.

scholarly journals Differential effects of intervention timing on COVID-19 spread in the United States

2020 ◽  
Vol 6 (49) ◽  
pp. eabd6370 ◽  
Author(s):  
Sen Pei ◽  
Sasikiran Kandula ◽  
Jeffrey Shaman
Keyword(s):  
United States ◽  
Disease Transmission ◽  
Human Mobility ◽  
The United States ◽  
Control Measures ◽  
Basic Reproductive Number ◽  
Transmission Model ◽  
Reproductive Number ◽  
Mobility Data ◽  
Nonpharmaceutical Interventions

Assessing the effects of early nonpharmaceutical interventions on coronavirus disease 2019 (COVID-19) spread is crucial for understanding and planning future control measures to combat the pandemic. We use observations of reported infections and deaths, human mobility data, and a metapopulation transmission model to quantify changes in disease transmission rates in U.S. counties from 15 March to 3 May 2020. We find that marked, asynchronous reductions of the basic reproductive number occurred throughout the United States in association with social distancing and other control measures. Counterfactual simulations indicate that, had these same measures been implemented 1 to 2 weeks earlier, substantial cases and deaths could have been averted and that delayed responses to future increased incidence will facilitate a stronger rebound of infections and death. Our findings underscore the importance of early intervention and aggressive control in combatting the COVID-19 pandemic.

scholarly journals Epidemic spreading model in heterogeneous conditions

2021 ◽  
pp. 1-12
Author(s):  
Andrey Viktorovich Podlazov
Keyword(s):  
Equilibrium Position ◽  
Sir Model ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Epidemic Spread ◽  
Epidemic Spreading ◽  
Oscillatory Dynamics ◽  
Spreading Model ◽  
Multiple Contacts ◽  
The Social

I propose two modifications of the SIR model of the epidemic spread, taking into account the social and space heterogeneity of the population. Social hetero¬geneity associated with differences in the intensity of paired contacts between people qualitatively changes the basic reproductive number. Space heterogeneity associated with differences in the intensity of multiple contacts between people significantly shifts the equilibrium position, increases the characteristic times and leads to the emergence of oscillatory dynamics of finite duration.

Dynamics of a Food Chain Model with Two Infected Predators

2021 ◽  
Vol 31 (02) ◽  
pp. 2150019
Author(s):  
Xin-You Meng ◽  
Ni-Ni Qin ◽  
Hai-Feng Huo
Keyword(s):  
Food Chain ◽  
Disease Transmission ◽  
Sufficient Conditions ◽  
Geometric Approach ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Chain Model ◽  
Number Formula ◽  
Manifold Theory ◽  
Food Chain Model

In this paper, the dynamics of a three-species food chain model with two predators infected by an infectious disease is investigated. The positivity and boundedness of the system, the existence of the equilibria and the basic reproductive number are given. Sufficient conditions for the local stability of all equilibria are obtained by analyzing the corresponding characteristic equations. By constructing suitable Lyapunov functions and taking the geometric approach, the global stability of all equilibria is proved. According to the center manifold theory, this model undergoes the phenomenon of backward and forward bifurcations in a certain range of the basic reproductive number [Formula: see text]. By taking the disease transmission coefficient of predator as bifurcation parameter, Hopf bifurcation emerges in the neighborhood of the endemic equilibrium. Furthermore, the optimal control of the disease is discussed by the Pontryagin’s maximum principle. Various simulations are given to support the analytical results.

scholarly journals Estimation of the Outbreak Severity and Evaluation of Epidemic Prevention Ability of COVID-19 by Province in China

2020 ◽  
Vol 110 (12) ◽  
pp. 1837-1843
Author(s):  
Yilei Ma ◽  
Xuehan Liu ◽  
Weiwei Tao ◽  
Yuchen Tian ◽  
Yanran Duan ◽  
...  
Keyword(s):  
Emergency Response ◽  
Disease Transmission ◽  
Initial Period ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Linear Mixed Effects Model ◽  
Linear Mixed Effects ◽  
Imported Cases ◽  
And Control ◽  
Case Data

Objectives. To compare the epidemic prevention ability of COVID-19 of each province in China and to evaluate the existing prevention and control capacity of each province. Methods. We established a quasi-Poisson linear mixed-effects model using the case data in cities outside Wuhan in Hubei Province, China. We adapted this model to estimate the number of potential cases in Wuhan and obtained epidemiological parameters. We estimated the initial number of cases in each province by using passenger flowrate data and constructed the extended susceptible–exposed–infectious–recovered model to predict the future disease transmission trends. Results. The estimated potential cases in Wuhan were about 3 times the reported cases. The basic reproductive number was 3.30 during the initial outbreak. Provinces with more estimated imported cases than reported cases were those in the surrounding provinces of Hubei, including Henan and Shaanxi. The regions where the number of reported cases was closer to the predicted value were most the developed areas, including Beijing and Shanghai. Conclusions. The number of confirmed cases in Wuhan was underestimated in the initial period of the outbreak. Provincial surveillance and emergency response capabilities vary across the country.

scholarly journals Personality in the context of social networks

2010 ◽  
Vol 365 (1560) ◽  
pp. 4099-4106 ◽  
Author(s):  
J. Krause ◽  
R. James ◽  
D. P. Croft
Keyword(s):  
Fine Structure ◽  
Social Network ◽  
Social Network Analysis ◽  
Network Analysis ◽  
Disease Transmission ◽  
Dyadic Relationships ◽  
Network Position ◽  
Animal Populations ◽  
The Social ◽  
Interactive Strategies

There is great interest in environmental effects on the development and evolution of animal personality traits. An important component of an individual's environment is its social environment. However, few studies look beyond dyadic relationships and try to place the personality of individuals in the context of a social network. Social network analysis provides us with many new metrics to characterize the social fine-structure of populations and, therefore, with an opportunity to gain an understanding of the role that different personalities play in groups, communities and populations regarding information or disease transmission or in terms of cooperation and policing of social conflicts. The network position of an individual is largely a consequence of its interactive strategies. However, the network position can also shape an individual's experiences (especially in the case of juveniles) and therefore can influence the way in which it interacts with others in future. Finally, over evolutionary time, the social fine-structure of animal populations (as quantified by social network analysis) can have important consequences for the evolution of personalities—an approach that goes beyond the conventional game-theoretic analyses that assumed random mixing of individuals in populations.

Social status influences responses to unfamiliar conspecifics in a cooperatively breeding fish

Behaviour ◽  
2015 ◽  
Vol 152 (12-13) ◽  
pp. 1821-1839 ◽  
Author(s):  
Isaac Y. Ligocki ◽  
Adam R. Reddon ◽  
Jennifer K. Hellmann ◽  
Constance M. O’Connor ◽  
Susan Marsh-Rollo ◽  
...  
Keyword(s):  
Social Status ◽  
Cichlid Fish ◽  
Group Living ◽  
Costs And Benefits ◽  
Control Groups ◽  
High Ranking ◽  
The Social ◽  
Cooperatively Breeding ◽  
Group Members ◽  
Group Member

In group living animals, individuals may visit other groups. The costs and benefits of such visits for the members of a group will depend on the attributes and intentions of the visitor, and the social status of responding group members. Using wild groups of the cooperatively breeding cichlid fish (Neolamprologus pulcher), we compared group member responses to unfamiliar ‘visiting’ conspecifics in control groups and in experimentally manipulated groups from which a subordinate the same size and sex as the visitor was removed. High-ranking fish were less aggressive towards visitors in removal groups than in control groups; low-ranking subordinates were more aggressive in the removal treatment. High-ranking females and subordinates the same size and sex as the visitor responded most aggressively toward the visitor in control groups. These results suggest that visitors are perceived as potential group joiners, and that such visits impose different costs and benefits on current group members.

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