Rumor propagation meets skepticism: a parallel with zombies

We propose a model of rumor spreading in which susceptible, but skeptically oriented individuals may oppose the rumor. Resistance may be implemented either by skeptical activists trying to convince spreaders to stop their activity, becoming stiflers or, passively (non-reactive) as a consequence, for example, of fact-checking. Interestingly, these two mechanisms, when combined, are similar to the (assumed) spreading of a fictitious zombie outbreak, where survivors actively target infected people. We analyse the well-mixed (mean-field) description and obtain the conditions for rumors (zombies) to spread through the whole population. The results show that when the skepticism is strong enough, the model predicts the coexistence of two fixed points (such bistability may be related to polarized situations), with the fate of rumors depending on the initial exposure to it

Photon emission in a constant magnetic field in 2+1 dimensional space-time

We calculate by the proper-time method the amplitude of the two-photon emission by a charged fermion in a constant magnetic field in (2+1)-dimensional space-time. The relevant dynamics reduces to that of a supesymmetric quantum-mechanical system with one bosonic and one fermionic degrees of freedom.Comment: 18 pages. v2: references added, some significant changes in the introductio

Assessing Economic Complexity with Input-Output Based Measures

Economic complexity can be defined as the level of interdependence between the component parts of an economy. In input-output systems, intersectoral connectedness is a crucial feature of analysis, and there are many different methods for measuring it. Most of the measures, however, have drawbacks that prevent them from being used as a good indicator of economic complexity, because they were not explicitly made with this purpose in mind. In this paper, we present, discuss and compare empirically different indexes of economic complexity as intersectoral connectedness, using the interindustry tables of several OECD countries.input-output analysis; intersectoral connectedness; economic complexity

A New Kind of Production Multiplier for Assessing the Scale and Structure Effects of Demand Shocks in Input-Output Frameworks

The main purpose of this paper is to develop a new kind of input-output multiplier that would be particularly well suited to quantifying the impacts of final demand changes on the sectoral output growth potential of an economy. Instead of using the traditional output multipliers, solving an appropriate optimization problem provides what can be called input-output Euclidean distance multipliers. This method does not impose unitary final demand shocks with a fixed (predetermined) structure, allowing the “IO economy” to change across the spectrum of all possible structures. It can be very helpful in measuring interindustry linkages and key sectors in a national or regional economy. An empirical illustration is made, using national (Spain and Portugal) and regional (Balearic Islands and the Azores) input-output data.input-output analysis; ultra-peripheral regions; structural change

Comment on: Kinetic Roughening in Slow Combustion of Paper

We comment on a recent Letter by Maunuksela et al. [Phys. Rev. Lett. 79, 1515 (1997)].Comment: 1 page, 1 figure, http://polymer.bu.edu/~hmakse/Home.htm

Macaque cardiac physiology is sensitive to the valence of passively viewed sensory stimuli.

Autonomic nervous system activity is an important component of affective experience. We demonstrate in the rhesus monkey that both the sympathetic and parasympathetic branches of the autonomic nervous system respond differentially to the affective valence of passively viewed video stimuli. We recorded cardiac impedance and an electrocardiogram while adult macaques watched a series of 300 30-second videos that varied in their affective content. We found that sympathetic activity (as measured by cardiac pre-ejection period) increased and parasympathetic activity (as measured by respiratory sinus arrhythmia) decreased as video content changes from positive to negative. These findings parallel the relationship between autonomic nervous system responsivity and valence of stimuli in humans. Given the relationship between human cardiac physiology and affective processing, these findings suggest that macaque cardiac physiology may be an index of affect in nonverbal animals