Theories for influencer identification in complex networks

In social and biological systems, the structural heterogeneity of interaction networks gives rise to the emergence of a small set of influential nodes, or influencers, in a series of dynamical processes. Although much smaller than the entire network, these influencers were observed to be able to shape the collective dynamics of large populations in different contexts. As such, the successful identification of influencers should have profound implications in various real-world spreading dynamics such as viral marketing, epidemic outbreaks and cascading failure. In this chapter, we first summarize the centrality-based approach in finding single influencers in complex networks, and then discuss the more complicated problem of locating multiple influencers from a collective point of view. Progress rooted in collective influence theory, belief-propagation and computer science will be presented. Finally, we present some applications of influencer identification in diverse real-world systems, including online social platforms, scientific publication, brain networks and socioeconomic systems.Comment: 24 pages, 6 figure

Socio-economic analysis of North Rhine-Westphalia: joint research projekt INCO-COPERNICUS

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Livelihood Diversification In Coastal and Inland Fishing Communities: Misconceptions, Evidence and Implications for Fisheries Management

This is the working paper regarding the Sustainable Fisheries Livelihoods Programme (SFLP). Diversification is a process by which households engage in multiple income generating activities. It is widely seen in the academic literature and international development arena as a strategy for spreading risk and reducing vulnerability. The formulation of policies promoting diversification is thus encouraged at national levels to alleviate poverty. However, such policies involve delicate choices and trade-offs between government objectives of development, e.g. intensification of agriculture and increase in agricultural outputs to satisfy export markets, versus increased household well-being and resilience to adversity through the promotion of small-scale, household-based, activities. In the context of fisheries, diversification is promoted as a means for reducing dependence on the resource, making restrictive management easier and less controversial for those affected by such measures. This often interprets diversification as job-substitution (stop fishing, do something else) rather than adding other activities to an income-portfolio. With the tendency for increasing pressure on fishery resources, it becomes ever more necessary to address in a coherent way diversification and its links with both poverty reduction and responsible fisheries. Implications of the development of alternative or complementary activities alongside a main, resource-dependent activity such as fishing, may echo those experienced by sectors such as agriculture and pastoralism. However, many characteristics of the fishing activity and of those who engage in it are particular to the sector. General poverty alleviation policies and fisheries management schemes have been found to lack the necessary differentiation and to fail to cater for the specific needs of fishing communities (Smith et al. 2005). The lack of attention -- or misplaced attention through maladapted policies -- that the sector and the communities it supports have received so far can be traced to a number of misconceptions stemming from "the old paradigm on poverty in small-scale fisheries" (Béné, 2003, p950). These assumptions include that (after Béné 2003, Allison and Ellis 2001): -- Fishing is an ingrained activity in fishing communities and fishermen will not leave fishing for cultural reasons. -- Fishermen are specialised and carry out fishing on a professional basis only. -- Fishing is a last resort activity and fishermen are unable to diversify into other income-generating activities. -- Fisheries development and development of fishing communities is not possible without increasing fishing effort. -- Livelihood diversification in fishing communities cannot go hand in hand with a sustainable natural resources management that encompasses both sustainable fisheries management and poverty alleviation. It is the aim of this paper to challenge these assumptions. Because of its linkages with resource management, looking at diversification in fishing communities involves re-exploring the issue from a different perspective than its current interpretation and most widely-encountered application to agricultural (land-based)-livelihoods. Despite the potential broad remit of this task, the objective here is to remain focused on the necessity to dispel misconceptions and show the need to formulate policies that support the engagement of fisherfolk and their families in multiple activities. By doing so, the paper shall also provide a compilation and review of available information related to diversification in fishing communities and point out the complexity of the issue of diversification in these communities. The geographical scope of the paper is global, guided by the availability of case study material, though reference to the West African experiences of the Sustainable Fisheries Livelihoods Programme (SFLP) is made wherever possible. Unless expressed otherwise, the terms 'fisheries' or 'fishers' make implicit reference to artisanal fisheries and the small-scale operations and modus operandi of those relying on them

Tackling food marketing to children in a digital world: trans-disciplinary perspectives. Children’s rights, evidence of impact, methodological challenges, regulatory options and policy implications for the WHO European Region

There is unequivocal evidence that childhood obesity is influenced by marketing of foods and non-alcoholic beverages high in saturated fat, salt and/or free sugars (HFSS), and a core recommendation of the WHO Commission on Ending Childhood Obesity is to reduce children’s exposure to all such marketing. As a result, WHO has called on Member States to introduce restrictions on marketing of HFSS foods to children, covering all media, including digital, and to close any regulatory loopholes. This publication provides up-to-date information on the marketing of foods and non-alcoholic beverages to children and the changes that have occurred in recent years, focusing in particular on the major shift to digital marketing. It examines trends in media use among children, marketing methods in the new digital media landscape and children’s engagement with such marketing. It also considers the impact on children and their ability to counter marketing as well as the implications for children’s rights and digital privacy. Finally the report discusses the policy implications and some of the recent policy action by WHO European Member States