HST Observations of Giant Arcs: High Resolution Imaging Of Distant Field Galaxies.

We present HST imaging of eight spectroscopically-confirmed giant arcs, pairs and arclets. These objects have all been extensively studied from the ground and we demonstrate the unique advantages of HST imaging in the study of such features by a critical comparison of our data with the previous observations. In particular we present new estimates of the core radii of two clusters (Cl0024+16, A370) determined from lensed features which are identifiable in our HST images. Although our HST observations include both pre- and post-refurbishment images, the depth of the exposures guarantees that the majority of the arcs are detected with diffraction-limited resolution. A number of the objects in our sample are multiply-imaged and we illustrate the ease of identification of such features when working at high resolution. We discuss the morphological and scale information on these distant field galaxies in the light of HST studies of lower redshift samples. We conclude that the dominant population of star-forming galaxies at z=1 is a factor of 1.5-2 times smaller than the similar group in the local field. This implies either a considerable evolution in the sizes of star-forming galaxies within the last $\sim$10 Gyrs or a shift in the relative space densities of massive and dwarf star-forming systems over the same timescale.Comment: 9 pages (no figures), uuencoded, compressed Postscript. Postscript text, tables and figures (803 Kb) available via anonymous ftp in at ftp://ociw.edu//pub/irs/pub/hstarcs.tar.

Radio Galaxy Zoo: The Distortion of Radio Galaxies by Galaxy Clusters

We study the impact of cluster environment on the morphology of a sample of 4304 extended radio galaxies from Radio Galaxy Zoo. A total of 87% of the sample lies within a projected 15 Mpc of an optically identified cluster. Brightest cluster galaxies (BCGs) are more likely than other cluster members to be radio sources, and are also moderately bent. The surface density as a function of separation from cluster center of non-BCG radio galaxies follows a power law with index $-1.10\pm 0.03$ out to $10~r_{500}$ ($\sim 7~$Mpc), which is steeper than the corresponding distribution for optically selected galaxies. Non-BCG radio galaxies are statistically more bent the closer they are to the cluster center. Within the inner $1.5~r_{500}$ ($\sim 1~$Mpc) of a cluster, non-BCG radio galaxies are statistically more bent in high-mass clusters than in low-mass clusters. Together, we find that non-BCG sources are statistically more bent in environments that exert greater ram pressure. We use the orientation of bent radio galaxies as an indicator of galaxy orbits and find that they are preferentially in radial orbits. Away from clusters, there is a large population of bent radio galaxies, limiting their use as cluster locators; however, they are still located within statistically overdense regions. We investigate the asymmetry in the tail length of sources that have their tails aligned along the radius vector from the cluster center, and find that the length of the inward-pointing tail is weakly suppressed for sources close to the center of the cluster.Comment: 23 pages, 17 figures, 2 tables. Supplemental data files available in The Astronomical Journal or contact autho

Potential for rapid antibody detection to identify tuberculous cattle with non-reactive tuberculin skin test results

Abstract Background Bovine tuberculosis (TB) control programs generally rely on the tuberculin skin test (TST) for ante-mortem detection of Mycobacterium bovis-infected cattle. Results Present findings demonstrate that a rapid antibody test based on Dual-Path Platform (DPP®) technology, when applied 1-3 weeks after TST, detected 9 of 11 and 34 of 52 TST non-reactive yet M. bovis-infected cattle from the US and GB, respectively. The specificity of the assay ranged from 98.9% (n = 92, US) to 96.0% (n = 50, GB) with samples from TB-free herds. Multi-antigen print immunoassay (MAPIA) revealed the presence of antibodies to multiple antigens of M. bovis in sera from TST non-reactors diagnosed with TB. Conclusions Thus, use of serologic assays in series with TST can identify a significant number of TST non-reactive tuberculous cattle for more efficient removal from TB-affected herds

Fourth Workshop on Sustainable Software for Science: Practice and Experiences (WSSSPE4)

This report records and discusses the Fourth Workshop on Sustainable Software for Science: Practice and Experiences (WSSSPE4). The report includes a description of the keynote presentation of the workshop, the mission and vision statements that were drafted at the workshop and finalized shortly after it, a set of idea papers, position papers, experience papers, demos, and lightning talks, and a panel discussion. The main part of the report covers the set of working groups that formed during the meeting, and for each, discusses the participants, the objective and goal, and how the objective can be reached, along with contact information for readers who may want to join the group. Finally, we present results from a survey of the workshop attendees

Gamma-Ray Emission Concurrent with the Nova in the Symbiotic Binary V407 Cygni

Novae are thermonuclear explosions on a white dwarf surface fueled by mass accreted from a companion star. Current physical models posit that shocked expanding gas from the nova shell can produce X-ray emission but emission at higher energies has not been widely expected. Here, we report the Fermi Large Area Telescope detection of variable gamma-ray (0.1-10 GeV) emission from the recently-detected optical nova of the symbiotic star V407 Cygni. We propose that the material of the nova shell interacts with the dense ambient medium of the red giant primary, and that particles can be accelerated effectively to produce pi0 decay gamma-rays from proton-proton interactions. Emission involving inverse Compton scattering of the red giant radiation is also considered and is not ruled out.Comment: 38 pages, includes Supplementary Online Material; corresponding authors: C.C. Cheung, A.B. Hill, P. Jean, S. Razzaque, K.S. Woo

Cross-National Differences in Victimization : Disentangling the Impact of Composition and Context

Varying rates of criminal victimization across countries are assumed to be the outcome of countrylevel structural constraints that determine the supply ofmotivated o¡enders, as well as the differential composition within countries of suitable targets and capable guardianship. However, previous empirical tests of these ‘compositional’ and ‘contextual’ explanations of cross-national di¡erences have been performed upon macro-level crime data due to the unavailability of comparable individual-level data across countries. This limitation has had two important consequences for cross-national crime research. First, micro-/meso-level mechanisms underlying cross-national differences cannot be truly inferred from macro-level data. Secondly, the e¡ects of contextual measures (e.g. income inequality) on crime are uncontrolled for compositional heterogeneity. In this paper, these limitations are overcome by analysing individual-level victimization data across 18 countries from the International CrimeVictims Survey. Results from multi-level analyses on theft and violent victimization indicate that the national level of income inequality is positively related to risk, independent of compositional (i.e. micro- and meso-level) di¡erences. Furthermore, crossnational variation in victimization rates is not only shaped by di¡erences in national context, but also by varying composition. More speci¢cally, countries had higher crime rates the more they consisted of urban residents and regions with lowaverage social cohesion.

Phototoxic aptamers selectively enter and kill epithelial cancer cells

The majority of cancers arise from malignant epithelial cells. We report the design of synthetic oligonucleotides (aptamers) that are only internalized by epithelial cancer cells and can be precisely activated by light to kill such cells. Specifically, phototoxic DNA aptamers were selected to bind to unique short O-glycan-peptide signatures on the surface of breast, colon, lung, ovarian and pancreatic cancer cells. These surface antigens are not present on normal epithelial cells but are internalized and routed through endosomal and Golgi compartments by cancer cells, thus providing a focused mechanism for their intracellular delivery. When modified at their 5′ end with the photodynamic therapy agent chlorin e6 and delivered to epithelial cancer cells, these aptamers exhibited a remarkable enhancement (>500-fold increase) in toxicity upon light activation, compared to the drug alone and were not cytotoxic towards cell types lacking such O-glycan-peptide markers. Our findings suggest that these synthetic oligonucleotide aptamers can serve as delivery vehicles in precisely routing cytotoxic cargoes to and into epithelial cancer cells

Emergence of Epidemic Neisseria meningitidis Serogroup X Meningitis in Togo and Burkina Faso

Serogroup X meningococci (NmX) historically have caused sporadic and clustered meningitis cases in sub-Saharan Africa. To study recent NmX epidemiology, we analyzed data from population-based, sentinel and passive surveillance, and outbreak investigations of bacterial meningitis in Togo and Burkina Faso during 2006–2010. Cerebrospinal fluid specimens were analyzed by PCR. In Togo during 2006–2009, NmX accounted for 16% of the 702 confirmed bacterial meningitis cases. Kozah district experienced an NmX outbreak in March 2007 with an NmX seasonal cumulative incidence of 33/100,000. In Burkina Faso during 2007–2010, NmX accounted for 7% of the 778 confirmed bacterial meningitis cases, with an increase from 2009 to 2010 (4% to 35% of all confirmed cases, respectively). In 2010, NmX epidemics occurred in northern and central regions of Burkina Faso; the highest district cumulative incidence of NmX was estimated as 130/100,000 during March–April. Although limited to a few districts, we have documented NmX meningitis epidemics occurring with a seasonal incidence previously only reported in the meningitis belt for NmW135 and NmA, which argues for development of an NmX vaccine