Bounded Confidence under Preferential Flip: A Coupled Dynamics of Structural Balance and Opinions

In this work we study the coupled dynamics of social balance and opinion formation. We propose a model where agents form opinions under bounded confidence, but only considering the opinions of their friends. The signs of social ties -friendships and enmities- evolve seeking for social balance, taking into account how similar agents' opinions are. We consider both the case where opinions have one and two dimensions. We find that our dynamics produces the segregation of agents into two cliques, with the opinions of agents in one clique differing from those in the other. Depending on the level of bounded confidence, the dynamics can produce either consensus of opinions within each clique or the coexistence of several opinion clusters in a clique. For the uni-dimensional case, the opinions in one clique are all below the opinions in the other clique, hence defining a "left clique" and a "right clique". In the two-dimensional case, our numerical results suggest that the two cliques are separated by a hyperplane in the opinion space. We also show that the phenomenon of unidimensional opinions identified by DeMarzo, Vayanos and Zwiebel (Q J Econ 2003) extends partially to our dynamics. Finally, in the context of politics, we comment about the possible relation of our results to the fragmentation of an ideology and the emergence of new political parties.Comment: 8 figures, PLoS ONE 11(10): e0164323, 201

The cost of phage resistance in a plant pathogenic bacterium is context-dependent.

Parasites are ubiquitous features of living systems and many parasites severely reduce the fecundity or longevity of their hosts. This parasite-imposed selection on host populations should strongly favor the evolution of host resistance, but hosts typically face a trade-off between investment in reproductive fitness and investment in defense against parasites. The magnitude of such a trade-off is likely to be context-dependent, and accordingly costs that are key in shaping evolution in nature may not be easily observable in an artificial environment. We set out to assess the costs of phage resistance for a plant pathogenic bacterium in its natural plant host versus in a nutrient-rich, artificial medium. We demonstrate that mutants of Pseudomonas syringae that have evolved resistance via a single mutational step pay a substantial cost for this resistance when grown on their tomato plant hosts, but do not realize any measurable growth rate costs in nutrient-rich media. This work demonstrates that resistance to phage can significantly alter bacterial growth within plant hosts, and therefore that phage-mediated selection in nature is likely to be an important component of bacterial pathogenicity

The co-evolutionary relationship between energy service companies and the UK energy system: Implications for a low-carbon transition

The Energy Service Company (ESCo) business model is designed to reward businesses by satisfying consumers' energy needs at less cost and with fewer carbon emissions via energy demand management and/or sustainable supply measures. In contrast, the revenue of the incumbent Energy Utility Company (EUCo) model is coupled with the sale of units of energy, which are predominantly sourced from fossil fuels. The latter is currently dominant in the UK. This paper addresses two questions. First, why has the ESCo model traditionally been confined to niche applications? Second, what role is the ESCo model likely to play in the transition to a low-carbon UK energy system? To answer these, the paper examines the core characteristics of the ESCo model, relative to the EUCo model. The paper then examines how ESCos have co-evolved with the various dimensions of the energy system (i.e. ecosystems, institutions, user practices, technologies and business models) to provide insight into how ESCos might help to shape the future UK energy system. We suggest that institutional and technological changes within the UK energy system could result in a more favourable selection environment for ESCos, consequently enabling the ESCo model to proliferate at the expense of the EUCo model. © 2013 Elsevier Ltd

Spatial heterogeneity, frequency-dependent selection and polymorphism in host-parasite interactions

<p>Abstract</p> <p>Background</p> <p>Genomic and pathology analysis has revealed enormous diversity in genes involved in disease, including those encoding host resistance and parasite effectors (also known in plant pathology as avirulence genes). It has been proposed that such variation may persist when an organism exists in a spatially structured metapopulation, following the geographic mosaic of coevolution. Here, we study gene-for-gene relationships governing the outcome of plant-parasite interactions in a spatially structured system and, in particular, investigate the population genetic processes which maintain balanced polymorphism in both species.</p> <p>Results</p> <p>Following previous theory on the effect of heterogeneous environments on maintenance of polymorphism, we analysed a model with two demes in which the demes have different environments and are coupled by gene flow. Environmental variation is manifested by different coefficients of natural selection, the costs to the host of resistance and to the parasite of virulence, the cost to the host of being diseased and the cost to an avirulent parasite of unsuccessfully attacking a resistant host. We show that migration generates negative direct frequency-dependent selection, a condition for maintenance of stable polymorphism in each deme. Balanced polymorphism occurs preferentially if there is heterogeneity for costs of resistance and virulence alleles among populations and to a lesser extent if there is variation in the cost to the host of being diseased. We show that the four fitness costs control the natural frequency of oscillation of host resistance and parasite avirulence alleles. If demes have different costs, their frequencies of oscillation differ and when coupled by gene flow, there is amplitude death of the oscillations in each deme. Numerical simulations show that for a multiple deme island model, costs of resistance and virulence need not to be present in each deme for stable polymorphism to occur.</p> <p>Conclusions</p> <p>Our theoretical results confirm the importance of empirical studies for measuring the environmental heterogeneity for genetic costs of resistance and virulence alleles. We suggest that such studies should be developed to investigate the generality of this mechanism for the long-term maintenance of genetic diversity at host and parasite genes.</p

Rethinking the Dutch Innovation Agenda: Management and Organization Matter Most

In this essay, we challenge the present dominant emphasis in the Dutch Innovation Debate on the creation of technological innovations, the focus on a few core technologies, and the allocation of more financial resources. We argue that managerial capabilities and organizing principles for innovation should have a higher priority on the Dutch Innovation Agenda. Managerial capabilities for innovation deal with cognitive elements such as the capacity to absorb knowledge, create entrepreneurial mindsets, and facilitate managerial experimentation and higher-order learning abilities. These capacities can only be developed by distinctive managerial roles that enhance hierarchy, teaming and shared norms. Utilizing these unique managerial capabilities requires novel organizing principles, such as managing internal rates of change, nurturing self-organization and balancing high levels of exploration and exploitation. These managerial capabilities and organizing principles of innovation create new sources of productivity growth and competitive advantage.The dramatic fall back of the Netherlands in the league of innovative and high productivity countries of the World Economic Forum-Report can be mainly attributed to the present lack in the Netherlands of these key managerial and organizational enablers of innovation and productivity growth. We provide various levers for building unique managerial capabilities and novel organizing principles of innovation. Moreover, we describe the necessary roles that different actors have to play in this innovation arena. In particular, we focus on the often neglected but important role of strategic regulations that speed up innovation and productivity growth. They are the least expensive way to boost innovation in organizations in both the Dutch private and public sector. Finally, we discuss the implications for the Dutch Innovation Agenda. It should start with setting a challenging ambition, namely the return of The Netherlands within the WEF- league of the top-ten most innovative and productive countries of the world. Considering the under-utilization of available knowledge stemming from technological innovations, managerial and organizational determinants of innovation should receive first priority. These determinants have a high strategic relevance and should receive more public recognition. We suggest to organize an annual innovation ranking of the most outstanding Dutch firms, to develop an innovation audit that measures firms’ non-technological innovation capacity, and to create an overall innovation policy for fast diffusion of new managerial capabilities and adequate organizing principles throughout the Dutch private and public sector.In conclusion, we add five new items to the Dutch Innovation Agenda:1. Prioritize administrative innovationsInvestments in management and organization determinants of absorption of knowledge and its successful application (administrative innovation) should have a higher priority than investments in technological innovations.2. Build new managerial capabilities and develop novel organizing principlesFor these administrative innovations to succeed, firms have to build managerial capabilities (broad knowledge-base, absorptive capacity, managerial experimentation, higher-order learning) and various management roles (hierarchy, teaming, shared norms) to increase the assimilation of external knowledge and the utilization for innovation. Moreover, they have to develop novel organizing principles that increase internal rates of change, nurture self-organization and synchronize high levels of exploration and exploitation.3. Set levers of innovation by creating selection environments that favor innovation and by redefining the roles of key actors Management has to create a proper organizational context to foster entrepreneurship and innovation (internal selection environment). Governmental agencies have to focus on innovation and productivity enabling strategic regulations (external selection environment). Moreover, research institutes, business schools, and consulting firms should not only focus on technological knowledge, but also on managerial and organizational knowledge for innovation. In the end, private small and large firms and public institutions have to recognize that they all must contribute to the national goal of increasing innovation and productivity growth.4. Create a new challenging national ambition: return of the Netherlands within the top-10The Netherlands has to return to the top-ten most innovative and productive countries in the world as reflected in international rankings such as the World Economic Forum’s Global Competitiveness Index.5. Proliferate an awareness and passion for innovation:Create public awareness and recognition of the societal relevance of outstanding managerial capabilities and organizing principles to innovation and productivity growth:o Initiate a Dutch innovation ranking in terms of management and organization;o Develop proper assessment tools for innovations in management and organization;o Enhance reporting on the progress on managerial and organizational innovation as part of modern corporate governance and as part of outstanding annual reports.These issues may contribute to rethinking the fundamental sources of innovation, productivity growth and sustainable competitive advantage of the Dutch economy.dynamic capabilities;knowledge transfer;exploitation;exploration;mANAGEMENT;mindsets;organizing pinciples;srategic rgulation;strategy innovation