FDI, terrorism and the availability heuristic for U.S. investors before and after 9/11

We record the existence of an availability heuristic that is reflected in disaster myopia of U.S. investors and exists prior to the attacks of 9/11. We argue that this is fueled by an aggregate experience hypothesis effect, resulting in a pronounced increase in the sensitivity of U.S. stock prices to terrorist attacks on foreign soil. After 9/11, stock prices react proportionally to the size of an attack and the share of FDI stock held in the region by the sector in which firms operate. This effect, non-existent prior to 2002, has become increasingly strong in recent years

Turbulence and turbulent pattern formation in a minimal model for active fluids

Active matter systems display a fascinating range of dynamical states, including stationary patterns and turbulent phases. While the former can be tackled with methods from the field of pattern formation, the spatio-temporal disorder of the active turbulence phase calls for a statistical description. Borrowing techniques from turbulence theory, we here establish a quantitative description of correlation functions and spectra of a minimal continuum model for active turbulence. Further exploring the parameter space, we also report on a surprising type of turbulence-driven pattern formation far beyond linear onset: the emergence of a dynamic hexagonal vortex lattice state after an extended turbulent transient, which can only be explained taking into account turbulent energy transfer across scales.Comment: Supplemental videos available at https://youtu.be/gbf6cRho03w https://youtu.be/n0qUUhAUJFQ https://youtu.be/LGmamkM012

Foraging <i>Macrotermes natalensis</i> fungus-growing termites avoid a mycopathogen but not an entomopathogen

Fungus-growing termites have to defend both themselves and their monoculture fungal cultivars from antagonistic microbes. One of the ways that pathogens can enter the termite colony is on the plant substrate that is collected by termite foragers. In order to understand whether foragers avoid substrate infected with antagonists, we offered sub-colonies of Macrotermes natalensis a choice between food exposed to either a mycopathogenic or an entomopathogenic fungus, and control food. Workers did not show any preference between entomopathogen-exposed and control substrate, but significantly avoided the mycopathogen-exposed substrate. This suggests that the behaviour of foraging workers is more strongly influenced by pathogens affecting their crop than those posing risks to the termite workers themselves

Offshell effects in electromagnetic reactions on the deuteron

Offshell contributions to the electromagnetic nuclear current are evaluated within a nonrelativistic approach by incorporation one-pion loop contributions in time-ordered perturbation theory. By construction, the correct experimental onshell properties of the nucleon current are ensured so that only the genuine offshell effects appear as model dependent. For a qualitative assessment of such offshell effects, this model is applied to photodisintegration of the deuteron for photon energies up to 500 MeV. While at low energies offshell contributions are small, above 300 MeV they lead to sizeable effects in observables up to about 30 percent pointing to the necessity of incorporating such effects if one aims at theoretical predictions of high precision.Comment: 22 pages revtex including 17 figure