The Emergence of a Twisted Flux Tube into the Solar Atmosphere: Sunspot Rotations and the Formation of a Coronal Flux Rope

We present a 3D simulation of the dynamic emergence of a twisted magnetic flux tube from the top layer of the solar convection zone into the solar atmosphere and corona. It is found that after a brief initial stage of flux emergence during which the two polarities of the bipolar region become separated and the tubes intersecting the photosphere become vertical, significant rotational motion sets in within each polarity. The rotational motions of the two polarities are found to twist up the inner field lines of the emerged fields such that they change their orientation into an inverse configuration (i.e. pointing from the negative polarity to the positive polarity over the neutral line). As a result, a flux rope with sigmoid-shaped, dipped core fields form in the corona, and the center of the flux rope rises in the corona with increasing velocity as the twisting of the flux rope footpoints continues. The rotational motion in the two polarities is a result of propagation of non-linear torsional Alfv\'en waves along the flux tube, which transports significant twist from the tube's interior portion towards its expanded coronal portion. This is a basic process whereby twisted flux ropes are developed in the corona with increasing twist and magnetic energy, leading up to solar eruptions.Comment: 33 pages, 14 figures, Submitted to Ap

Degree Variance and Emotional Strategies Catalyze Cooperation in Dynamic Signed Networks

We study the problem of the emergence of cooperation in dynamic signed networks where agent strategies coevolve with relational signs and network topology. Running simulations based on an agent-based model, we compare results obtained in a regular lattice initialization with those obtained on a comparable random network initialization. We show that the increased degree heterogeneity at the outset enlarges the parametric conditions in which cooperation survives in the long run. Furthermore, we show how the presence of sign-dependent emotional strategies catalyze the evolution of cooperation with both network topology initializations.Comment: 16 Pages, Proceeding of the European Conference on Modelling and Simumatio

Conditioned emergence: a dissipative structures approach to transformation

This paper presents a novel framework for the management of organisational transformation, defined here as a relatively rapid transition from one archetype to another. The concept of dissipative structures, from the field of complexity theory, is used to develop and explain a specific sequence of activities which underpin effective transformation. This sequence integrates selected concepts from the literatures on strategic change, organisational learning and business processes; in so doing, it introduces a degree of prescriptiveness which differentiates it from other managerial interpretations of complexity theory. Specifically, it proposes a three-stage process: first, the organisation conditions the outcome of the transformation process by articulating and reconfiguring the rules which underpin its deep structure; second, it takes steps to move from its current equilibrium and, finally, it moves into a period where positive and negative feedback loops become the focus of managerial attention. The paper argues that by managing at the level of deep structure in social systems, organisations can gain some influence over self-organising processes which are typically regarded as unpredictable in the natural sciences. However, the paper further argues that this influence is limited to archetypal features and that detailed forms and behaviours are emergent properties of the system. Two illustrative case-vignettes are presented to give an insight into the practical application of the model before conclusions are reached which speculate on the implications of this approach for strategy research

Fashion, Cooperation, and Social Interactions

Fashion plays such a crucial rule in the evolution of culture and society that it is regarded as a second nature to the human being. Also, its impact on economy is quite nontrivial. On what is fashionable, interestingly, there are two viewpoints that are both extremely widespread but almost opposite: conformists think that what is popular is fashionable, while rebels believe that being different is the essence. Fashion color is fashionable in the first sense, and Lady Gaga in the second. We investigate a model where the population consists of the afore-mentioned two groups of people that are located on social networks (a spatial cellular automata network and small-world networks). This model captures two fundamental kinds of social interactions (coordination and anti-coordination) simultaneously, and also has its own interest to game theory: it is a hybrid model of pure competition and pure cooperation. This is true because when a conformist meets a rebel, they play the zero sum matching pennies game, which is pure competition. When two conformists (rebels) meet, they play the (anti-) coordination game, which is pure cooperation. Simulation shows that simple social interactions greatly promote cooperation: in most cases people can reach an extraordinarily high level of cooperation, through a selfish, myopic, naive, and local interacting dynamic (the best response dynamic). We find that degree of synchronization also plays a critical role, but mostly on the negative side. Four indices, namely cooperation degree, average satisfaction degree, equilibrium ratio and complete ratio, are defined and applied to measure people's cooperation levels from various angles. Phase transition, as well as emergence of many interesting geographic patterns in the cellular automata network, is also observed.Comment: 21 pages, 12 figure

An illusion induced by an illusion -perceptual filling-in of coloured negative afterimages

Visual filling-in relates to a perceptual phenomenon in which a stimulus pattern apparently undergoes dynamic changes assuming an attribute such as colour, texture, or brightness from the surround. This perceptual completion effect has up to now been shown only for real images. Here, we present filling-in in negative afterimages, a phenomenon not yet reported. Using coloured disk-ring patterns for stimuli, we demonstrate that afterimage filling-in arises independently, and is not simply a replica of filling-in observed in real images. Such filling-in does not occur when the afterimage is elicited dichoptically, suggesting its emergence within the monocular visual pathway. In this way, our findings indicate that filling-in under certain conditions may derive from an active neural mechanism located at low levels of the visual pathway

Politics 2.0: the Multifaceted Effect of Broadband Internet on Political Participation

We investigate the causal impact of broadband Internet on political participation using data from Italy. We show that this impact varies across different forms of political engagement and over time. Initially, broadband had a negative effect on turnout in national elections, driven by increased abstention of ideologically extreme voters. Meanwhile, however, broadband fostered other forms of online and offline participation. Over time, the negative effect was reverted due to the emergence of new political entrepreneurs who used the Internet to convert the initial “exit” back into “voice”. Overall, these nuanced effects underscore the general equilibrium dynamic induced by the Internet

Turing structures in dc gas discharges

Self-organized spatial plasma structures exhibit many similarities with Turing structures obtained in biology and chemistry. Using an analytical mesoscopic approach it is shown that plasma balls of fire belong to the same class of Turing structures like the Brusselator. It is also mathematically proved that the existence of these self-organized plasma structures is related with a negative differential resistance. There are also established the mathematical conditions which the negative differential resistance must satisfy for obtaining a stationary ball of fire at the anode of a plasma diode.Comment: 5 pages, 1 figur