The Clustering Of Galaxies Around Radio-Loud AGNs

We examine the hypothesis that mergers and close encounters between galaxies can fuel AGNs by increasing the rate at which gas accretes towards the central black hole. We compare the clustering of galaxies around radio-loud AGNs with the clustering around a population of radio-quiet galaxies with similar masses, colors and luminosities. Our catalog contains 2178 elliptical radio galaxies with flux densities greater than 2.8 mJy at 1.4 GHz from the 6dFGS survey. We find that radio AGNs with more than 200 times the median radio power have, on average, more close (r<160 kpc) companions than their radio-quiet counterparts, suggestive that mergers play a role in forming the most powerful radio galaxies. For ellipticals of fixed stellar mass, the radio power is not a function of large-scale environment nor halo mass, consistent with the radio powers of ellipticals varying by orders of magnitude over billions of years.Comment: 12 pages, 6 figure

On the average value of divisor sums in arithmetic progressions

This is a pre-copy-editing, author-produced PDF of an article accepted for publication in International Mathematics Research Notices. The definitive publisher-authenticated version William D. Banks, Roger Heath-Brown and Igor E. Shparlinski, On the average value of divisor sums in arithmetic progressions, Int Math Res Notices 2005 (1): 1-25, is available online at: http://imrn.oxfordjournals.org/content/2005/1/1.abstract. doi: 10.1155/IMRN.2005.1. © 2005 Hindawi Publishing Corporation.We consider very short sums of the divisor function in arithmetic progressions prime to a fixed modulus and show that "on average" these sums are close to the expected value. We also give applications of our result to sums of the divisor function twisted with characters (both additive and multiplicative) taken on the values of various functions, such as rational and exponential functions; in particular, we obtain upper bounds for such twisted sums

Echinococcus granulosus Infection and Options for Control of Cystic Echinococcosis in Tibetan Communities of Western Sichuan Province, China

Human cystic echinococcosis (CE) is highly endemic in Tibetan regions of Sichuan. As part of a control program for CE in Datangma district, Ganzi County, necropsy of strays and coproantigen-ELISA of all dogs was carried out prior to and post-drug treatment to determine the efficacy of the treatment for control. Examination of sheep/goats and yaks was undertaken to determine the baseline transmission pressure to dogs. The necropsy results indicated no apparent significant change in the overall prevalence of E. granulosus in unwanted dogs after 5 years of 6-month treatment. In contrast, there was a highly significant decrease in Echinococcus prevalence in domestic/stray dogs after the 5-year treatment program shown by coproantigen-ELISA. This indicated a decreasing but continuing risk for re-infection of dogs resulting from high infection pressure from the numerous infected domestic animals. DNA genotyping indicated the presence only of the sheep strain (G1) of E. granulosus in the study area. A combination of livestock vaccination with the highly effective Eg95 vaccine and dog drug treatment, targeting two critical points of the parasite life-cycle, would avoid the conflicts of religion or local culture and achieve the goal of hydatid control in the long term in the area

Validation of Ray Tracing Code Refraction Effects

NASA's current predictive capabilities using the ray tracing program (RTP) are validated using helicopter noise data taken at Eglin Air Force Base in 2007. By including refractive propagation effects due to wind and temperature, the ray tracing code is able to explain large variations in the data observed during the flight test

On a Theorem of de Finetti, Oddsmaking, and Game Theory

1 online resource (PDF, 10 pages

On Finitely Additive Priors, Coherence, and Extended Admissibility

1 online resource (PDF, 25 pages

The Limit of a Random Walk and The Number Theoretic Density

1 online resource (PDF, 11 pages

Continuous-Time Gambling Problems

1 online resource (PDF, 26 pages

The democratic engagement of Britain's ethnic minorities

Democratic engagement is a multi-faceted phenomenon that embraces citizens' involvement with electoral politics, their participation in ‘conventional’ extra-parliamentary political activity, their satisfaction with democracy and trust in state institutions, and their rejection of the use of violence for political ends. Evidence from the 2010 BES and EMBES shows that there are important variations in patterns of democratic engagement across Britain's different ethnic-minority groups and across generations. Overall, ethnic-minority engagement is at a similar level to and moved by the same general factors that influence the political dispositions of whites. However, minority democratic engagement is also strongly affected by a set of distinctive ethnic-minority perceptions and experiences, associated particularly with discrimination and patterns of minority and majority cultural engagement. Second-generation minorities who grew up in Britain are less, rather than more, likely to be engaged