Synthetic Observations of the HI Line in SPH-Simulated Spiral Galaxies

Using the radiative transfer code Torus, we produce spectral-line cubes of the predicted HI profile from global SPH simulations of spiral galaxies. Torus grids the SPH galaxy using Adaptive Mesh Refinement, then applies a ray-tracing method to infer the HI profile along the line(s) of sight. The gridded galaxy can be observed from any direction, which enables us to model the observed HI profile for galaxies of any orientation. We can also place the observer inside the galaxy, to simulate HI observations taken from the Earth's position in the Milky Way.Comment: 4 pages, 2 figures, conference proceedings for "Panoramic Radio Astronomy: 1-2 Ghz Research on Galaxy Evolution" June 2-5, 2009 Groninge

Coping with Shocks and Shifts: The Multilateral Trading System in Historical Perspective

This paper provides a historical look at how the multilateral trading system has coped with the challenge of shocks and shifts. By shocks we mean sudden jolts to the world economy in the form of financial crises and deep recessions, or wars and political conflicts. By shifts we mean slow-moving, long-term changes in comparative advantage or shifts in the geopolitical equilibrium that force economies to undergo disruptive and potentially painful adjustments. We conclude that most shocks (financial crises and regional wars) have had relatively little effect on trade policy, but that shifts pose a greater challenge to the system of open, multilateral trade.

The knowledge-based software assistant

Where the Knowledge Based Software Assistant (KBSA) is now, four years after the initial report, is discussed. Also described is what the Rome Air Development Center expects at the end of the first contract iteration. What the second and third contract iterations will look like are characterized

Exploring GLIMPSE Bubble N107: Multiwavelength Observations and Simulations

Context. Bubble N107 was discovered in the infrared emission of dust in the Galactic Plane observed by the Spitzer Space Telescope (GLIMPSE survey: l ~ 51.0 deg, b ~ 0.1 deg). The bubble represents an example of shell-like structures found all over the Milky Way Galaxy. Aims. We aim to analyse the atomic and molecular components of N107, as well as its radio continuum emission. With the help of numerical simulations, we aim to estimate the bubble age and other parameters which cannot be derived directly from observations. Methods. From the observations of the HI (I-GALFA) and 13CO (GRS) lines we derive the bubble's kinematical distance and masses of the atomic and molecular components. With the algorithm DENDROFIND, we decompose molecular material into individual clumps. From the continuum observations at 1420 MHz (VGPS) and 327 MHz (WSRT), we derive the radio flux density and the spectral index. With the numerical code ring, we simulate the evolution of stellar-blown bubbles similar to N107. Results. The total HI mass associated with N107 is 5.4E3 Msun. The total mass of the molecular component (a mixture of cold gasses of H2, CO, He and heavier elements) is 1.3E5 Msun, from which 4.0E4 Msun is found along the bubble border. We identified 49 molecular clumps distributed along the bubble border, with the slope of the clump mass function of -1.1. The spectral index of -0.30 of a strong radio source located apparently within the bubble indicates nonthermal emission, hence part of the flux likely originates in a supernova remnant, not yet catalogued. The numerical simulations suggest N107 is likely less than 2.25 Myr old. Since first supernovae explode only after 3 Myr or later, no supernova remnant should be present within the bubble. It may be explained if there is a supernova remnant in the direction towards the bubble, however not associated with it.Comment: 15 pages, 11 figure

Computational translation of genomic responses from experimental model systems to humans

The high failure rate of therapeutics showing promise in mouse models to translate to patients is a pressing challenge in biomedical science. Though retrospective studies have examined the fidelity of mouse models to their respective human conditions, approaches for prospective translation of insights from mouse models to patients remain relatively unexplored. Here, we develop a semi-supervised learning approach for inference of disease-associated human differentially expressed genes and pathways from mouse model experiments. We examined 36 transcriptomic case studies where comparable phenotypes were available for mouse and human inflammatory diseases and assessed multiple computational approaches for inferring human biology from mouse datasets. We found that semi-supervised training of a neural network identified significantly more true human biological associations than interpreting mouse experiments directly. Evaluating the experimental design of mouse experiments where our model was most successful revealed principles of experimental design that may improve translational performance. Our study shows that when prospectively evaluating biological associations in mouse studies, semi-supervised learning approaches, combining mouse and human data for biological inference, provide the most accurate assessment of human in vivo disease processes. Finally, we proffer a delineation of four categories of model system-to-human "Translation Problems" defined by the resolution and coverage of the datasets available for molecular insight translation and suggest that the task of translating insights from model systems to human disease contexts may be better accomplished by a combination of translation-minded experimental design and computational approaches.Boehringer Ingelheim PharmaceuticalsInstitute for Collaborative Biotechnologies (Grant W911NF-09-0001

Cross-Country Comparisons of Corporate Income Taxes

To our knowledge, this paper provides the most comprehensive analysis of firm-level corporate income taxes to date. We use publicly available financial statement information for 11,602 public corporations from 82 countries from 1988 to 2009 to estimate country-level effective tax rates (ETRs). We find that the location of a multinational and its subsidiaries substantially affects its worldwide ETR. Japanese firms always faced the highest ETRs. U.S. multinationals are among the highest taxed. Multinationals based in tax havens face the lowest taxes. We find that ETRs have been falling over the last two decades; however, the ordinal rank from high-tax countries to low-tax countries has changed little. We also find little difference between the ETRs of multinationals and domestic-only firms. Besides enhancing our knowledge about international taxes, these findings should provide some empirical underpinning for ongoing policy debates about the taxation of multinationals.