Jonathan Ward

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The spread of ideas across a social network can be studied using complex contagion models, in which agents are activated by contact with multiple activated neighbors. The investigation of complex contagions can provide crucial insights into social influence and behavior-adoption cascades on networks. In this paper, we introduce a model of a multi-stage(More)
Heavy-tailed distributions of meme popularity occur naturally in a model of meme diffusion on social networks. Competition between multiple memes for the limited resource of user attention is identified as the mechanism that poises the system at criticality. The popularity growth of each meme is described by a critical branching process, and asymptotic(More)
Participants with schizophrenia (N = 59) were assessed on self-evaluation, symptomatology, and positive and negative affect (expressed emotion) from significant others. An interview-based measure of self-evaluation was used and two independent dimensions of self-esteem were derived: negative and positive evaluation of self. As predicted, negative(More)
Homophily and social influence are the fundamental mechanisms that drive the evolution of attitudes, beliefs and behaviour within social groups. Ho-mophily relates the similarity between pairs of individuals' attitudinal states to their frequency of interaction, and hence structural tie strength, while social influence causes the convergence of individuals'(More)
Mean-field analysis is an important tool for understanding dynamics on complex networks. However , surprisingly little attention has been paid to the question of whether mean-field predictions are accurate, and this is particularly true for real-world networks with clustering and modular structure. In this paper, we compare mean-field predictions to(More)
Conceptualizing aetiology underpinning an individual's substance use disorder (SUD) not only facilitates insight and understanding, but also serves to identify targets for treatment and aid practitioners in selecting the most appropriate interventions. There is now a wealth of literature on aetiology and treatment approaches, and in more recent years, also(More)
BACKGROUND Substance misuse services within the United Kingdom have traditionally been oriented to opiate and crack users, and attended predominantly by male service users. Groups who do not fit this demographic, such as women or those whose primary drug of choice is neither heroin nor crack, have tended to be underrepresented in services. In addition,(More)
Supplement Aims and Scope or limited or prevented to help protect human health and our environment. In a field where the literature is ever-expanding, practitioners and researchers increasingly need to have ready access to up-to-date, high-quality scholarly articles on areas of ongoing interest in environmental health. This supplement aims to address this(More)