472 research outputs found
The Origins of Terrorism: Cross-Country Estimates on Socio-economic Determinants of Terrorism
As a prerequisite of an appropriate anti-terror strategy, it is indispensable to assess the underlying causes of terror. We examine social and economic conditions in the country of origin of terrorist attacks, claiming that low opportunity costs of terror, e.g., approximated by slow growth and poor institutions raise the likelihood of terror and the willingness in the population to support terror. Using a negative binomial regression model, we are able to show that unfortunate socio-economic conditions in a country are likely to reduce the opportunity costs of potential terrorists and increase the number of terrorist attacks originating from a specific country. Interestingly, this effect is particularly relevant after a certain level of development has been reached. We therefore distinguish between several broad country groups, namely the OECD, Europe and Islamic countries.terror attacks, openness, discrete choice analysis, institutions
The Origins of Terrorism - Cross-Country Estimates on Socio-Economic Determinants of Terrorism
To expand our knowledge about an appropriate anti-terror strategy, it is indispensable to assess the underlying causes of terror. We examine social and economic conditions in the country of origin of terrorist attacks, claiming that low opportunity costs of terror, e.g. approximated as slow growth and poor institutions raise the propensity of terror and the willingness in the population to support terror. Using a mixed effects Poisson regression model, we are able to show that unfortunate socio-economic conditions in a country are suitable to reduce the opportunity cost for potential terrorists and increase the likelihood of terrorist attacks originating from a specific country. Interestingly, this effect is relevant after a certain level of development has been reached. We therefore distinguish between the OECD, Europe and Islamic countries.terror attacks, openness, discrete choice analysis, institutions
The Origins of Terrorism: Cross-Country Estimates on Socio-economic Determinants of Terrorism
As a prerequisite of an appropriate anti-terror strategy, it is indispensable to assess the underlying causes of terror. We examine social and economic conditions in the country of origin of terrorist attacks, claiming that low opportunity costs of terror, e.g., approximated by slow growth and poor institutions raise the likelihood of terror and the willingness in the population to support terror. Using a negative binomial regression model, we are able to show that unfortunate socio-economic conditions in a country are likely to reduce the opportunity costs of potential terrorists and increase the number of terrorist attacks originating from a specific country. Interestingly, this effect is particularly relevant after a certain level of development has been reached. We therefore distinguish between several broad country groups, namely the OECD, Europe and Islamic countries
The origins of terrorism cross-country estimates on socio-economic determinants of terrorism
To expand our knowledge about an appropriate anti-terror strategy, it is indispensable to assess the underlying causes of terror. We examine social and economic conditions in the country of origin of terrorist attacks, claiming that low opportunity costs of terror, e.g. approximated as slow growth and poor institutions raise the propensity of terror and the willingness in the population to support terror. Using a mixed effects Poisson regression model, we are able to show that unfortunate socio-economic conditions in a country are suitable to reduce the opportunity cost for potential terrorists and increase the likelihood of terrorist attacks originating from a specific country. Interestingly, this effect is relevant after a certain level of development has been reached. We therefore distinguish between the OECD, Europe and Islamic countries
The spin 1/2 Heisenberg star with frustration II: The influence of the embedding medium
We investigate the spin 1/2 Heisenberg star introduced in J. Richter and A.
Voigt, J. Phys. A: Math. Gen. {\bf 27}, 1139 (1994). The model is defined by
; , . In extension to the Ref. we consider a more general
describing the properties of the spins surrounding the
central spin . The Heisenberg star may be considered as an essential
structure element of a lattice with frustration (namely a spin embedded in a
magnetic matrix ) or, alternatively, as a magnetic system with a
perturbation by an extra spin. We present some general features of the
eigenvalues, the eigenfunctions as well as the spin correlation of the model. For being a linear chain, a square
lattice or a Lieb-Mattis type system we present the ground state properties of
the model in dependence on the frustration parameter .
Furthermore the thermodynamic properties are calculated for being a
Lieb--Mattis antiferromagnet.Comment: 16 pages, uuencoded compressed postscript file, accepted to J. Phys.
A: Math. Ge
Hydrodynamic coupling and rotational mobilities near planar elastic membranes
We study theoretically and numerically the coupling and rotational
hydrodynamic interactions between spherical particles near a planar elastic
membrane that exhibits resistance towards shear and bending. Using a
combination of the multipole expansion and Faxen's theorems, we express the
frequency-dependent hydrodynamic mobility functions as a power series of the
ratio of the particle radius to the distance from the membrane for the self
mobilities, and as a power series of the ratio of the radius to the
interparticle distance for the pair mobilities. In the quasi-steady limit of
zero frequency, we find that the shear- and bending-related contributions to
the particle mobilities may have additive or suppressive effects depending on
the membrane properties in addition to the geometric configuration of the
interacting particles relative to the confining membrane. To elucidate the
effect and role of the change of sign observed in the particle self and pair
mobilities, we consider an example involving a torque-free doublet of
counterrotating particles near an elastic membrane. We find that the induced
rotation rate of the doublet around its center of mass may differ in magnitude
and direction depending on the membrane shear and bending properties. Near a
membrane of only energetic resistance toward shear deformation, such as that of
a certain type of elastic capsules, the doublet undergoes rotation of the same
sense as observed near a no-slip wall. Near a membrane of only energetic
resistance toward bending, such as that of a fluid vesicle, we find a reversed
sense of rotation. Our analytical predictions are supplemented and compared
with fully resolved boundary integral simulations where a very good agreement
is obtained over the whole range of applied frequencies.Comment: 14 pages, 7 figures. Revised manuscript resubmitted to J. Chem. Phy
Trauma systems and early management of severe injuries in scandinavia: review and current status
publishedVersio
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