scholarly journals Epidemics on hypergraphs: spectral thresholds for extinction

2021 ◽  
Vol 477 (2252) ◽  
pp. 20210232
Author(s):  
Desmond J. Higham ◽  
Henry-Louis de Kergorlay
Keyword(s):  
Mean Field ◽  
Nonlinear Function ◽  
Epidemic Spreading ◽  
Realistic Case ◽  
Contact Graph ◽  
Individual Level ◽  
Human Interactions ◽  
Hypergraph Model ◽  
Different Types ◽  
Flexible Models

Epidemic spreading is well understood when a disease propagates around a contact graph. In a stochastic susceptible–infected–susceptible setting, spectral conditions characterize whether the disease vanishes. However, modelling human interactions using a graph is a simplification which only considers pairwise relationships. This does not fully represent the more realistic case where people meet in groups. Hyperedges can be used to record higher order interactions, yielding more faithful and flexible models and allowing for the rate of infection of a node to depend on group size and also to vary as a nonlinear function of the number of infectious neighbours. We discuss different types of contagion models in this hypergraph setting and derive spectral conditions that characterize whether the disease vanishes. We study both the exact individual-level stochastic model and a deterministic mean field ODE approximation. Numerical simulations are provided to illustrate the analysis. We also interpret our results and show how the hypergraph model allows us to distinguish between contributions to infectiousness that (i) are inherent in the nature of the pathogen and (ii) arise from behavioural choices (such as social distancing, increased hygiene and use of masks). This raises the possibility of more accurately quantifying the effect of interventions that are designed to contain the spread of a virus.

scholarly journals DISSIPATIVE QUANTUM DISORDERED MODELS

2006 ◽  
Vol 20 (19) ◽  
pp. 2795-2804 ◽  
Author(s):  
LETICIA F. CUGLIANDOLO
Keyword(s):  
Glassy Phase ◽  
Quantum Critical Point ◽  
Mean Field ◽  
Static Properties ◽  
One Dimensional ◽  
Time Dynamics ◽  
Long Range Interactions ◽  
Disordered Models ◽  
Different Types ◽  
Dissipative Environments

This article reviews recent studies of mean-field and one dimensional quantum disordered spin systems coupled to different types of dissipative environments. The main issues discussed are: (i) The real-time dynamics in the glassy phase and how they compare to the behaviour of the same models in their classical limit. (ii) The phase transition separating the ordered – glassy – phase from the disordered phase that, for some long-range interactions, is of second order at high temperatures and of first order close to the quantum critical point (similarly to what has been observed in random dipolar magnets). (iii) The static properties of the Griffiths phase in random king chains. (iv) The dependence of all these properties on the environment. The analytic and numeric techniques used to derive these results are briefly mentioned.

scholarly journals Modeling neutral viral mutations in the spread of SARS-CoV-2 epidemics

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0255438
Author(s):  
Vitor M. Marquioni ◽  
Marcus A. M. de Aguiar
Keyword(s):  
Population Genetics ◽  
Analytical Solution ◽  
Genetic Distance ◽  
Mean Field ◽  
Neutral Evolution ◽  
Genetic Evolution ◽  
Epidemic Spreading ◽  
Different Strains ◽  
Over Time ◽  
Good Agreement

Although traditional models of epidemic spreading focus on the number of infected, susceptible and recovered individuals, a lot of attention has been devoted to integrate epidemic models with population genetics. Here we develop an individual-based model for epidemic spreading on networks in which viruses are explicitly represented by finite chains of nucleotides that can mutate inside the host. Under the hypothesis of neutral evolution we compute analytically the average pairwise genetic distance between all infecting viruses over time. We also derive a mean-field version of this equation that can be added directly to compartmental models such as SIR or SEIR to estimate the genetic evolution. We compare our results with the inferred genetic evolution of SARS-CoV-2 at the beginning of the epidemic in China and found good agreement with the analytical solution of our model. Finally, using genetic distance as a proxy for different strains, we use numerical simulations to show that the lower the connectivity between communities, e.g., cities, the higher the probability of reinfection.

Early Treatment Change in Perpetrators of Sexual Versus Non-Sexual Violence

2021 ◽  
pp. 0306624X2110655
Author(s):  
Marije Keulen-de Vos ◽  
Massil Benbouriche
Keyword(s):  
Physical Violence ◽  
Violent Behavior ◽  
Psychiatric Nurses ◽  
Reliable Change Index ◽  
Treatment Change ◽  
Individual Level ◽  
Mixed Analysis ◽  
Different Types ◽  
Male Patients ◽  
Over Time

The purpose of this study is to assess treatment change at both a group and individual level in a sample of 81 Dutch male patients who received mandated care for either violent (non-sexual) behavior or sexual violent behavior. Psychiatric nurses rated patients’ social skills, insight, hostility, physical violence with the BEST-Index every 6 months over the course of 2 years after patients were admitted to hospital. Mixed analysis of covariances and the reliable change index indicated that patients, irrespective of offense type, showed treatment change over time with exception of physical violence. This study shows that general treatment may be useful in the first 18 month for risk factors common to different types of offenses, but that specialized treatment is needed to establish further change.

Hypernetwork models based on random hypergraphs

2019 ◽  
Vol 30 (08) ◽  
pp. 1950052
Author(s):  
Feng Hu ◽  
Jin-Li Guo ◽  
Fa-Xu Li ◽  
Hai-Xing Zhao
Keyword(s):  
Field Theory ◽  
Mean Field Theory ◽  
Mean Field ◽  
World Systems ◽  
Uniform Hypergraphs ◽  
Different Types ◽  
Powerful Means ◽  
Simulation Results ◽  
Parameter Values ◽  
Random Hypergraphs

Hypernetworks are ubiquitous in real-world systems. They provide a powerful means of accurately depicting networks of different types of entity and will attract more attention from researchers in the future. Most previous hypernetwork research has been focused on the application and modeling of uniform hypernetworks, which are based on uniform hypergraphs. However, random hypernetworks are generally more common, therefore, it is useful to investigate the evolution mechanisms of random hypernetworks. In this paper, we construct three dynamic evolutional models of hypernetworks, namely the equal-probability random hypernetwork model, the Poisson-probability random hypernetwork model and the certain-probability random hypernetwork model. Furthermore, we analyze the hyperdegree distributions of the three models with mean-field theory, and we simulate each model numerically with different parameter values. The simulation results agree well with the results of our theoretical analysis, and the findings indicate that our models could help understand the structure and evolution mechanisms of real systems.

The distributional effects of the Social Security windfall elimination provision

2013 ◽  
Vol 12 (4) ◽  
pp. 415-434 ◽  
Author(s):  
JEFFREY R. BROWN ◽  
SCOTT J. WEISBENNER
Keyword(s):  
Social Security ◽  
Nonlinear Function ◽  
Social Security Administration ◽  
Cross Sectional ◽  
Individual Level ◽  
Alternative Method ◽  
Data Limitations ◽  
The Social ◽  
State And Local ◽  
Lifetime Earnings

AbstractOver five million state and local government employees have lifetime earnings that are divided between employment that is covered by the Social Security system and employment that is not covered. As Social Security benefits are a nonlinear function of covered lifetime earnings, the simple application of the standard benefit formula to covered earnings only would provide a higher replacement rate on those earnings than is appropriate given the individuals' total (covered plus uncovered) lifetime earnings. The Windfall Elimination Provision (WEP), established in 1983, is intended to correct this situation by applying a modified benefit formula to earnings of individuals with non-covered employment. This paper analyzes the distributional implications of the WEP and finds that it reduces benefits disproportionately for individuals with lower lifetime covered earnings. It discusses an alternative method of calculating the WEP that comes closer to preserving the intended redistribution of the system. In recognition of historical data limitations that prevent the Social Security Administration (SSA) from being able to implement this alternative method at present, the paper also analyzes two alternative ways of calculating the WEP that use the same information as the current WEP, are budget neutral, and come closer to maintaining the individual-level, cross-sectional progressivity of Social Security than does the existing WEP formula.

scholarly journals Associations between frequency of food shopping at different store types and diet and weight outcomes: findings from the NEWPATH study

2016 ◽  
Vol 19 (12) ◽  
pp. 2268-2277 ◽  
Author(s):  
Leia M Minaker ◽  
Dana L Olstad ◽  
Mary E Thompson ◽  
Kim D Raine ◽  
Pat Fisher ◽  
...  
Keyword(s):  
Diet Quality ◽  
Saturated Fat ◽  
Healthy Eating Index ◽  
Farmers Markets ◽  
Food Store ◽  
Individual Level ◽  
Food Shopping ◽  
Different Types ◽  
Weight Outcomes ◽  
Purchasing Patterns

AbstractObjectiveThe present study aimed to: (i) examine associations between food store patronage and diet and weight-related outcomes; and (ii) explore consumer motivations for visiting different types of food store.DesignA stratified probability sample of residents completed household and individual-level surveys in 2009/2010 on food purchasing patterns and motivations, dietary intake, waist circumference (WC), weight and height. Diet quality was calculated using the Healthy Eating Index for Canada from a subset of participants (n 1362). Generalized estimating equations were created in 2015 to examine how frequency of patronizing different types of food store was associated with diet quality, intake of fruits and vegetable, mean intake of energy (kcal) sodium and saturated fat, WC and BMI.SettingThree mid-sized urban municipalities in Ontario, Canada.SubjectsA representative sample of residents (n 4574).ResultsParticipants who shopped frequently at food co-ops had significantly better diet quality (β=5·3; 99 % CI 0·3, 10·2) than those who did not. BMI and WC were significantly lower among those who frequently shopped at specialty shops (BMI, β=−2·1; 99 % CI −3·0, −1·1; WC, β=−4·8; 99 % CI −7·0, −2·5) and farmers’ markets (BMI, β=−1·4; 99 % CI −2·3, −0·5; WC, β=−3·8; 99 % CI −6·0, −1·6) compared with those who did not. Relative importance of reasons for food outlet selection differed by large (price, food quality) v. small (proximity, convenient hours) shopping trip and by outlet type.ConclusionsFindings contribute to our understanding of food store selection and have implications for potentially relevant retail food intervention settings.

EPIDEMIC SPREADING ON THREE-LAYER INTERDEPENDENT NETWORKS

2016 ◽  
Vol 24 (04) ◽  
pp. 469-494 ◽  
Author(s):  
LINGNA WANG ◽  
GUANGHU ZHU ◽  
HUIYAN KANG ◽  
XINCHU FU
Keyword(s):  
Infection Rate ◽  
Basic Reproduction Number ◽  
Reproduction Number ◽  
Mean Field ◽  
Network Size ◽  
Infection Rates ◽  
Epidemic Spreading ◽  
Interdependent Networks ◽  
Coupled Networks ◽  
The Basic Reproduction Number

Many epidemic diseases spread among three different populations with different contact patterns and infection rates. In response to such diseases, we propose two new types of three-layer interdependent networks — string-coupled networks and circular-coupled networks. We investigate an epidemic spreading on the two types of interdependent networks, propose two mathematical models through heterogeneous mean field approach and prove global stability of the disease-free and endemic equilibria. Through theoretical and numerical analysis, we find the following: the increase of each infection rate affects effectively only its own subnetwork and neighbors; in a string-coupled network, the middle subnetwork has bigger impact on the basic reproduction number than the end subnetworks with the growth of network size or infection rates; the basic reproduction number on a circular-coupled network is larger than that on a string-coupled network for a fixed network size; but the change of the basic reproduction number (or the average infection densities) is almost the same on both string-coupled and circular-coupled networks with the increasing of certain infection rate.

Civil Society and the Legacies of Dictatorship

2007 ◽  
Vol 59 (4) ◽  
pp. 539-567 ◽  
Author(s):  
Michael Bernhard ◽  
Ekrem Karakoç
Keyword(s):  
Civil Society ◽  
Hierarchical Linear Modeling ◽  
National Level ◽  
World Values Survey ◽  
Organizational Life ◽  
Linear Modeling ◽  
Individual Level ◽  
Civil Society Participation ◽  
Level Data ◽  
Different Types

The literature on civil society in postcommunist regimes highlights its weakness as compared with civil society in other democracies. In this article the authors make a general argument on how different patterns of antecedent dictatorship affect the development of civil society across a range of democracies. They examine the slow emergence of two behaviors associated with a robust civil society—participation in organizational life and in protest—and explain variation across countries as a function of regime history. They draw their individual-level data from the World Values Survey and analyze the behavior of over forty-one thousand citizens from forty-two democracies. Using methods of hierarchical linear modeling to control for both national-level and individual-level factors, the authors find that different types of dictatorship and variation in their duration produce different negative legacies for the development of civil society.

scholarly journals Temporal Contact Graph Reveals The Evolving Epidemic Situation of COVID-19

2021 ◽  
Author(s):  
Mincheng Wu ◽  
Chao Li ◽  
Zhangchong Shen ◽  
Shibo He ◽  
Lingling Tang ◽  
...  
Keyword(s):  
Participation Rate ◽  
Population Level ◽  
User Participation ◽  
Contact Tracing ◽  
Prevention Measures ◽  
Contact Graph ◽  
Individual Level ◽  
Related Data ◽  
Epidemic Size ◽  
Travel Restrictions

Abstract Digital contact tracing has been recently advocated by China and many countries as part of digital prevention measures on COVID-19. Controversies have been raised about their effectiveness in practice as it remains open how they can be fully utilized to control COVID-19. In this article, we show that an abundance of information can be extracted from digital contact tracing for COVID-19 prevention and control. Specifically, we construct a temporal contact graph that quantifies the daily contacts between infectious and susceptible individuals by exploiting a large volume of location-related data contributed by 10,527,737 smartphone users in Wuhan, China. The temporal contact graph reveals five time-varying indicators can accurately capture actual contact trends at population level, demonstrating that travel restrictions (e.g., city lockdown) in Wuhan played an important role in containing COVID-19. We reveal a strong correlation between the contacts level and the epidemic size, and estimate several significant epidemiological parameters (e.g., serial interval). We also show that user participation rate exerts higher influence on situation evaluation than user upload rate does. At individual level, however, the temporal contact graph plays a limited role, since the behavior distinction between the infected and uninfected contacted individuals are not substantial. The revealed results can tell the effectiveness of digital contact tracing against COVID-19, providing guidelines for governments to implement interventions using information technology.

scholarly journals Whose Realm, His Trust - Regional Disparities of Generalized Trust in Europe

2019 ◽  
Author(s):  
Fabian Stephany
Keyword(s):  
Driving Forces ◽  
National Level ◽  
European Social Survey ◽  
Generalized Trust ◽  
Social Survey ◽  
Individual Level ◽  
Regional Clusters ◽  
Commercial Transaction ◽  
Different Types ◽  
The Individual

Trust explains the functioning of markets, institutions or society as a whole. It is a key element in almost every commercial transaction over time and might be one of the main explanations of economic success and development. In Europe, the determinants of (generalized) trust have been investigated in the past. Most scholars have focused on aggregate (national) levels of trust. However, it can be assumed that driving forces, which foster or diminish trust, act at a sub-national level. Regional clusters remain undetected. With the use of the European Social Survey 6 and modern spatial diagnostics, this work examines the individual and regional determinants of trust in 88 European NUTS1 regions in 26 countries. There are two main findings. First, wealth, linguistic fragmentation, and religious ideologies shape trust on a regional level, education, income, and membership in associations foster trust on an individual level. Secondly, the study unravels regional dispersions in different types of "trust regimes" in Europe. Regional clusters of generalized trust are confirmed by spatial diagnostics. The "regionality" of trust could be of importance for future targeted policy making.

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