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 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 $H=J_1 \sum_{i=1}^{N}{{\bf s}_0{\bf s}_i} + J_2 H_{R}\{{\bf s}_i\}$ ; $J_1,J_2 \ge 0$ , $i=1,...,N$. In extension to the Ref. we consider a more general $H_{R}\{{\bf s}_i\}$ describing the properties of the spins surrounding the central spin ${\bf s}_0$. The Heisenberg star may be considered as an essential structure element of a lattice with frustration (namely a spin embedded in a magnetic matrix $H_R$) or, alternatively, as a magnetic system $H_R$ with a perturbation by an extra spin. We present some general features of the eigenvalues, the eigenfunctions as well as the spin correlation $\langle {\bf s}_0{\bf s}_i \rangle$ of the model. For $H_R$ 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 $\alpha=J_2/J_1$. Furthermore the thermodynamic properties are calculated for $H_R$ 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

A consensus-based template for documenting and reporting in physician-staffed pre-hospital services

Background: Physician-staffed pre-hospital units are employed in many Western emergency medical services (EMS) systems. Although these services usually integrate well within their EMS, little is known about the quality of care delivered, the precision of dispatch, and whether the services deliver a higher quality of care to pre-hospital patients. There is no common data set collected to document the activity of physician pre-hospital activity which makes shared research efforts difficult. The aim of this study was to develop a core data set for routine documentation and reporting in physician-staffed pre-hospital services in Europe. Methods: Using predefined criteria, we recruited sixteen European experts in the field of pre-hospital care. These experts were guided through a four-step modified nominal group technique. The process was carried out using both e-mail-based communication and a plenary meeting in Stavanger, Norway. Results: The core data set was divided into 5 sections: “fixed system variables”, “event operational descriptors”, “ patient descriptors”, “process mapping”, and “outcome measures and quality indicators”. After the initial round, a total of 361 variables were proposed by the experts. Subsequent rounds reduced the number of core variables to 45. These constituted the final core data set. Emphasis was placed on the standardisation of reporting time variables, chief complaints and diagnostic and therapeutic procedures. Conclusions: Using a modified nominal group technique, we have established a core data set for documenting and reporting in physician-staffed pre-hospital services. We believe that this template could facilitate future studies within the field and facilitate standardised reporting and future shared research efforts in advanced prehospital care.publishedVersio

Grignard synthesis of fluorinated nanoporous element organic frameworks based on the heteroatoms P, B, Si, Sn and Ge

We present the synthesis and characterization of fluorinated polymers based on P, B, Si, Sn and Ge as heteroatoms via Grignard activation. The polymers are microporous with hydrophobic surfaces. The borate-based polymer was successfully applied as solid acid catalyst in the esterification of acetic acid with ethanol. Grignard synthesis of fluorinated nanoporous element organic frameworks based on the heteroatoms P, B, Si, Sn and Ge Recently, porous polymers have attracted considerable attention as highly versatile materials for adsorption, separation and storage of gases, in catalysis, for optoelectronic applications and energy storage. Especially, metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) are of interest due to their high surface areas and pore volumes. In order to tune the surface polarity, porous ionic organic networks were reported. Depending on the desired properties such as porosity, polarity and functionality, these materials can be tailored for their application by varying the organic linker and connector element. The utilization of fluorinated linkers was reported for different MOFs and a COF, showing enhanced properties in terms of stability, hydrophobicity, gas affinity and selectivity in comparison to their non-fluorinated materials. In continuation of our work on element organic frameworks (EOFs) with P, Si and Sn as connector elements, here we present the synthesis and characterization of respective fluorinated porous polymers with P, B, Si, Sn and Ge as heteroatoms. The catalytic application of the borate based polymer as solid acid catalyst was demonstrated in the esterification of acetic acid with ethanol as test reaction. As the activation of the fluorinated biphenyl linker was not successful neither via lithiation as reported for the non-fluorinated linker nor via classical Grignard reaction, a magnesium-halogen exchange was applied. The linker 4,4′-dibromooctafluorbiphenyl was activated twofold with isopropylmagnesium chloride lithium chloride (turbo Grignard) and subsequent reaction with the respective element chlorides in a one-pot procedure (Scheme 1) resulted in the fluorinated polymers EF-EOF (E = P, B, Si, Sn, Ge). (Perfluorophenyl)-magnesium bromide was used for end-capping, converting remaining E–Cl bonds into E–Ar bonds to form fully substituted trivalent or tetravalent centers, respectively. In all cases, the resulting polymers were obtained as fluffy white powders