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 Ray Bundle method for calculating weak magnification by gravitational lenses

We present here an alternative method for calculating magnifications in gravitational lensing calculations -- the Ray Bundle method. We provide a detailed comparison between the distribution of magnifications obtained compared with analytic results and conventional ray-shooting methods. The Ray Bundle method provides high accuracy in the weak lensing limit, and is computationally much faster than (non-hierarchical) ray shooting methods to a comparable accuracy. The Ray Bundle method is a powerful and efficient technique with which to study gravitational lensing within realistic cosmological models, particularly in the weak lensing limit.Comment: 9 pages Latex, 8 figures, submitted to MNRA

Counting to Four: The History and Future of Wisconsin\u27s Fractured Supreme Court

Over the past decade, the Wisconsin Supreme Court has issued “fractured” opinions—decisions without majority support for any one legal rationale supporting the outcome—at an alarming clip. These opinions have confounded legal analysts, attorneys, and government officials due to their lack of majority reasoning, but also due to their length and the court’s particular procedures for assigning, drafting, and labelling opinions. This has become especially problematic where the court has issued fractured opinions in areas core to the basic functioning of state and local government, leaving the state without clear precedential guidance on what the law is. Yet, virtually no one has analyzed the deeper issues animating this predicament: how fractured opinions in Wisconsin have been handled in the past, what norms surround those choices, and why this problem has become so pronounced. This Article details the history of fractured opinions at the Wisconsin Supreme Court, from the state’s founding to the present, with a particular focus on the past twenty years and the development of the court’s current crisis. With this history in mind, along with (i) foundational principles of state judicial practice and (ii) the shortcomings of the United States Supreme Court’s approach to fractured opinions in Marks v. United States, 430 U.S. 188 (1977), a series of potential reforms are proposed. In particular, this Article suggests that the Wisconsin Supreme Court clearly define and explain what this Articl

The Effect of Variability on the Estimation of Quasar Black Hole Masses

We investigate the time-dependent variations of ultraviolet (UV) black hole mass estimates of quasars in the Sloan Digital Sky Survey (SDSS). From SDSS spectra of 615 high-redshift (1.69 < z < 4.75) quasars with spectra from two epochs, we estimate black hole masses, using a single-epoch technique which employs an additional, automated night-sky-line removal, and relies on UV continuum luminosity and CIV (1549A) emission line dispersion. Mass estimates show variations between epochs at about the 30% level for the sample as a whole. We determine that, for our full sample, measurement error in the line dispersion likely plays a larger role than the inherent variability, in terms of contributing to variations in mass estimates between epochs. However, we use the variations in quasars with r-band spectral signal-to-noise ratio greater than 15 to estimate that the contribution to these variations from inherent variability is roughly 20%. We conclude that these differences in black hole mass estimates between epochs indicate variability is not a large contributer to the current factor of two scatter between mass estimates derived from low- and high-ionization emission lines.Comment: 76 pages, 15 figures, 2 (long) tables; Accepted for publication in ApJ (November 10, 2007