Digital Commons Network^™

Open Angle Glaucoma Effects On Preattentive Visual Search (Pavs) Efficiency For Flicker, Motion Displacement And Orientation Pop-Out Tasks, James Loughman, Peter Davison, Daniel Ian Flitcroft

Articles

Background/aim: Preattentive visual search (PAVS) describes rapid and efficient retinal and neural processing capable of immediate target detection in the visual field. Damage to the nerve fibre layer or visual pathway might reduce the efficiency with which the visual system performs such analysis. The purpose of this study was to test the hypothesis that patients with glaucoma are impaired on parallel search tasks, and that this would serve to distinguish glaucoma in early cases. Methods: Three groups of observers (glaucoma patients, suspect and normal individuals) were examined, using computer-generated flicker, orientation, and vertical motion displacement targets to assess PAVS efficiency. …

Impact Of Astrophysical Processes On The Gamma-Ray Background From Dark Matter Annihilations, Eun-Joo Ahn, Gianfranco Bertone, David Merritt, Pengjie Zhang

Articles

We study the impact of astrophysical processes on the gamma-ray background produced by the annihilation of dark matter particles in cosmological halos, with particular attention to the consequences of the formation of supermassive black holes. In scenarios where these objects form adiabatically from the accretion of matter on small seeds, dark matter is first compressed into very dense “spikes”, then its density progressively decreases due to annihilations and scattering off of stellar cusps. With respect to previous analyses, based on non-evolving halos, the predicted annihilation signal is higher and significantly distorted at low energies, reflecting the large contribution to the …

Finding Time: How It Is Made Visual Artists Newsletter, Brian Fay

Articles

FINDING TIME

Brian Fay outlines the processes and concepts underpinning his practice

A Review Of Fiscal Measures To Benefit Heritage Conservation, Tracy Pickerill, Rob Pickard

Articles

This research paper explores to use of fiscal incentives for heritage conservation in a range of countries in Western Europe (Belgium, Denmark, France, Germany, Ireland, Italy, Netherlands, Spain and the United Kingdom) and North America (Canada and USA), to see how they are used and how effective they are.

The main incentives are:

• Income tax deductions and credits for costs incurred in heritage conservation activity;
• Income tax credits for the provision of social housing in heritage buildings;
• Property tax exemption, abatement or freeze for heritage buildings;
• Value added (sales) tax concessions or rebates relating to heritage conservation activity;
• Use of …

Performance Analysis Of Direct N-Body Algorithms On Special-Purpose Supercomputers, Stefan Harfst, Alessia Gualandris, David Merritt, Rainer Spurzem, Simon Portegies Zwart, Peter Berczik

Articles

Direct-summation N-body algorithms compute the gravitational interaction between stars in an exact way and have a computational complexity of O(N^2). Performance can be greatly enhanced via the use of special-purpose accelerator boards like the GRAPE-6A. However the memory of the GRAPE boards is limited. Here, we present a performance analysis of direct N-body codes on two parallel supercomputers that incorporate special-purpose boards, allowing as many as four million particles to be integrated. Both computers employ high-speed, Infiniband interconnects to minimize communication overhead, which can otherwise become significant due to the small number of "active" particles at each time step. We …

Open Angle Glaucoma Effects On Preattentive Visual Search (Pavs) Efficiency For Flicker, Motion Displacement And Orientation Pop-Out Tasks, James Loughman, Peter Davison, Ian Flitchcroft

Articles

Background/aim: Preattentive visual search (PAVS) describes rapid and efficient retinal and neural processing capable of immediate target detection in the visual field. Damage to the nerve fibre layer or visual pathway might reduce the efficiency with which the visual system performs such analysis. The purpose of this study was to test the hypothesis that patients with glaucoma are impaired on parallel search tasks, and that this would serve to distinguish glaucoma in early cases. Methods: Three groups of observers (glaucoma patients, suspect and normal individuals) were examined, using computer-generated flicker, orientation, and vertical motion displacement targets to assess PAVS efficiency. …

That’S A Fine Chablis You’Re Not Drinking: The Proper Place For Geographical Indications In Trademark Law, Justin Hughes, Lynne Beresford, Annette Kur, Kenneth Plevan, Susan Scafidi

Articles

No abstract provided.

How Special Are Brightest Cluster Galaxies? The Impact Of Near-Infrared Luminosities On Scaling Relations For Bcgs, Dan Batcheldor, Alessandro Marconi, David Merritt

Articles

Using the extended J, H and K magnitudes provided by the 2MASS data archive, we consider the position of brightest cluster galaxies (BCGs) in the observed relations between inferred supermassive black hole (SMBH) mass and the host galaxy properties, as well as their position in the stellar velocity dispersion and luminosity ( ∗ − L) relation, compared to E and S0 galaxies. We find that SMBH masses (M•) derived from near-infrared (NIR) magnitudes do not exceed 3×109M⊙ and that these masses agree well with the predictions made from ∗. In the NIR, there is no evidence that BCGs leave the …

Consequences Of Triaxiality For Gravitational Wave Recoil Of Black Holes, Alessandro Vicari, Roberto Capuzzo-Dolcetta, David Merritt

Articles

Coalescing binary black holes experience a “kick” due to anisotropic emission of gravitational waves with an amplitude as great as ∼ 200 km s−1. We examine the orbital evolution of black holes that have been kicked from the centers of triaxial galaxies. Time scales for orbital decay are generally longer in triaxial galaxies than in equivalent spherical galaxies, since a kicked black hole does not return directly through the dense center where the dynamical friction force is highest. We evaluate this effect by constructing self-consistent triaxial models and integrating the trajectories of massive particles after they are ejected from the …

On The Nature Of Optical Nuclei In Fr I Radio-Galaxies From Acs/Hst Imaging Polarimetry, Alessandro Capetti, David J. Axon, Marco Chiaberge, W. B. Sparks, F. Duccio Macchetto, M. Carcraft, A. Celotti

Articles

We obtained optical imaging polarimetry with the ACS/HRC aboard the HST of the 9 closest radiogalaxies in the 3C catalogue with an FR I morphology. The nuclear sources seen in direct HST images in these galaxies are found to be highly polarized with levels in the range 2 - 11 % with a median value of 7 %.We discuss the different mechanisms that produce polarized emission and conclude that the only viable interpretation is a synchrotron origin for the optical nuclei. This idea is strengthened by the analogy with the polarization properties of BL Lac objects, providing also further support …

Maximum Gravitational Recoil, Manuela Campanelli, Carlos O. Lousto, Yosef Zlochower, David Merritt

Articles

Recent calculations of gravitational radiation recoil generated during black-hole binary mergers have reopened the possibility that a merged binary can be ejected even from the nucleus of a massive host galaxy. Here we report the first systematic study of gravitational recoil of equal-mass binaries with equal, but counter-aligned, spins parallel to the orbital plane. Such an orientation of the spins is expected to maximize the recoil. We find that recoil velocity (which is perpendicular to the orbital plane) varies sinusoidally with the angle that the initial spin directions make with the initial linear momenta of each hole and scales up …

Key Skills Framework: Enhancing Employability Within A Lifelong Learning Paradigm, Aidan Kenny, Ray English, Dave Kilmartin

Articles

Employability has become an area of interest among the general public and policy makers alike, with an increasing number of reports in the general media regarding the need for workers in certain sectors to up-skill due to the possible threat of job ‘displacement’. In addition, there has been an increase in education and training policy documents emphasising that citizens should pursue Lifelong Learning /Life Wide Learning to address the increased job-related uncertainty attributed to the globalisation process and the concomitant competitive threats. Academics such as Barnett (2005) claim that we are living in an era of ‘super complexity' and rapid …

Evaluation Of The Idi-Mrsa Assay On The Smartcycler Real-Time Pcr Platform For Rapid Detection Of Mrsa From Screening Specimens, Celine Herra, A. S. Rossney, M. Fitzgibbon, P. Morgan, B. O’Connell

Articles

Rapid accurate detection is a prerequisite for the successful control of meticillin-resistant Staphylococcus aureus (MRSA). The IDI-MRSA real-time polymerase chain reaction (PCR) assay was designed to provide rapid results from nasal specimens collected in Stuart’s liquid transport medium. This study has evaluated the IDI-MRSA kit for use in a clinical laboratory by investigating the following parameters: (1) limits of detection (LoD), (2) performance with Amies’ gel-based transport medium, (3) ability to detect strains of MRSA in a collection representative of MRSA in Ireland since 1974 (n 113) and (4) performance in a clinical trial with swabs from nose, throat and …

Comparisons Of Binary Black Hole Merger Waveforms, John Baker, Manuela Campanelli, Frans Pretorius, Yosef Zlochower

Articles

This a particularly exciting time for gravitational wave physics. Ground-based gravitational wave detectors are now operating at a sensitivity such that gravitational radiation may soon be directly detected, and recently several groups have independently made significant breakthroughs that have finally enabled numerical relativists to solve the Einstein field equations for coalescing black-hole binaries, a key source of gravitational radiation. The numerical relativity community is now in the position to begin providing simulated merger waveforms for use by the data analysis community, and it is therefore very important that we provide ways to validate the results produced by various numerical approaches. …

Automated Extraction Of Fire Line Parameters From Multispectral Infrared Images, Ambrose Ononye, Anthony Vodacek, Eli Saber

Articles

Remotely sensed infrared images are often used to assess wildland ¯re conditions. Separately, ¯re propagation models are in use to forecast future conditions. In the Dynamic Data Driven Application System (DDDAS) concept, the ¯re propagation model will react to the image data, which should produce more accurate predictions of ¯re propagation. In this study we describe a series of image processing tools that can be used to extract ¯re propagation parameters from multispectral infrared images so that the parameters can be used to drive a ¯re propagation model built upon the DDDAS concept. The method is capable of automatically determining …

Suction Feeding Mechanics, Performance, And Diversity In Fishes, Peter Wainwright, Andrew Carroll, David Collar

Articles

Despite almost 50 years of research on the functional morphology and biomechanics of suction feeding, no consensus has emerged on how to characterize suction-feeding performance, or its morphological basis. We argue that this lack of unity in the literature is due to an unusually indirect and complex linkage between the muscle contractions that power suction feeding, the skeletal movements that underlie buccal expansion, the sharp drop in buccal suction pressure that occurs during expansion, the flow of water that enters the mouth to eliminate the pressure gradient, and the forces that are ultimately exerted on the prey by this flow. …

Model Atmospheres For Irradiated Giant Stars: Implications For The Galactic Center, Raul Jiminez, Juliana Silva, S. Peng Oh, Uffe G. Jørgensen, David Merritt

Articles

Irradiation of a stellar atmosphere by an external source (e.g. an AGN) changes its structure and therefore its spectrum. Using a state-of-the-art stellar atmosphere code, we calculate the infrared spectra of such irradiated and transformed stars. We show that the original spectrum of the star, which is dominated by molecular bands, changes dramatically when irradiated even by a low-luminosity AGN (LX = 1033 erg s−1), becoming dominated by atomic lines in absorption. We study the changes in the spectrum of low-mass carbon- and oxygen-rich giant stars as they are irradiated by a modest AGN, similar to the one at the …

Casting A Critical Eye On His Own Church : Heinrich Boll's ''The Clown'', Eamon Maher

Articles

Material reproduced by kind permission of Reality

Probability Thresholds, Jonathan Masur

Articles

Scholars and lower courts have traditionally operated under the belief that cases involving direct tradeoffs between free speech and national security call for the application of straightforward cost-benefit analysis. But the Supreme Court has refused to adhere to this approach, instead deciding difficult liberty-versus-security questions with reference to a "probability threshold"--a doctrinal floor defining how likely a potential threat must be in order to register in the constitutional calculus. This doctrinal innovation has served as a necessary corrective to what would otherwise be the systematic overestimation of speech-based threats driven by the interaction of two factors. First, distinct informational asymmetries …

Using The Technology Of The Confessional As An Analytical Resource: Four Analytical Stances Towards Research Interviews In Discourse Analysis, Brendan O'Rourke, Martyn Pitt

Articles

Among the various approaches that have developed from FOUCAULT's work is an Anglophone discourse analysis that has attempted to combine FOUCAULTian insights with the techniques of Conversation Analysis. An important current methodological issue in this discourse analytical approach is its theoretical preference for "naturally occurring" rather than research interview data. A FOUCAULTian perspective on the interview as a research instrument, questions the idea of "naturally-occurring discourse". The "technology of the confessional" operates, not only within research interviews, but permeates other interactions as well. Drawing on FOUCAULT does not dismiss the problems of the interview as research instrument rather it shows …

The Heating Mechanism For The Warm/Cool Dust In Powerful, Radio-Loud Active Galactic Nuclei, Clive Tadhunter, D. Dicken, J. Holt, K. Inskip, R. Morganti, David J. Axon, C. Buchanan, R. González Delgado, P. Barthel, I. Van Bemmel

Articles

The uncertainty surrounding the nature of the heating mechanism for the dust that emits at mid- to far-IR (MFIR) wavelengths in active galaxies limits our understanding of the links between active galactic nuclei (AGN) and galaxy evolution, as well as our ability to interpret the prodigious infrared and submm emission of some of the most distant galaxies in the Universe. Here we report deep Spitzer observations of a complete sample of powerful, intermediate redshift (0.05 < z < 0.7) radio galaxies and quasars. We show that AGN power, as traced by [OIII] 5007 emission, is strongly correlated with both the mid-IR (24μm) and the far-IR (70μm) luminosities, however, with increased scatter in the 70μm correlation. A major cause of this increased scatter is a group of objects that falls above the main correlation and displays evidence for prodigious recent star formation activity at optical wavelengths, along with relatively cool MFIR colours. These results provide evidence that illumination by the AGN is the primary heating mechanism for the dust emitting at both 24 and 70μm, with starbursts dominating the heating of the cool dust in only 20 – 30% of objects. This implies that powerful AGN are not always accompanied by the type of luminous starbursts that are characteristic of the peak of activity in major gas-rich mergers.

Hearing On "Practices Of The Credit Card Industry", Robert D. Manning

Articles

Prepared Statement of Robert D. Manning, PhD, Hearing on "Practices of the Credit Card Industry," before the New York Senate Standing Committee on Consumer Protection, Assembly Standing Committee on Consumer Affairs and Protection, Assembly Standing Committee on Banks.

An Analysis Of Economic Cost Minimization And Biological Invasion Damage Control Using The Awq Criterion, Gregory Deangelo, Amitrajeet Batabyal, Seshavadhani Kumar

Articles

DeAngelo et al. (2006) have recently used the AWS criterion in a M/G/1 queuing model to show that there is no necessary tension between economic cost minimization and inspection stringency in non-native species management. In this paper, we use an alternate cost criterion (AWQ criterion) to investigate the generality of this central result in DeAngelo et al. (2006). Our theoretical analysis shows that there is no unambiguous answer to this question. Therefore, we use numerical methods and our numerical analysis leads to two findings. First, for many values of the model parameters that describe the strictness of inspections, there is …

Spin Flips And Precession In Black-Hole-Binary Mergers, Manuela Campanelli, Carlos O. Lousto, Yosef Zlochower, Badri Krishnan, David Merritt

Articles

We use the ‘moving puncture’ approach to perform fully non-linear evolutions of spinning quasicircular black-hole binaries with individual spins unaligned with the orbital angular momentum. We evolve configurations with the individual spins (parallel and equal in magnitude) pointing in the orbital plane and 45◦ above the orbital plane. We introduce a technique to measure the spin direction and track the precession of the spin during the merger, as well as measure the spin flip in the remnant horizon. The former configuration completes 1.75 orbits before merging, with the spin precessing by 98◦ and the final remnant horizon spin flipped by …

Supermassive Black Holes In The Sbc Spiral Galaxies Ngc 3310, Ngc 4303 And Ngc 4258, Guia Pastorini, Alessandro Marconi, Alessandro Capetti, David J. Axon, Daniel Batcheldor, Et Al.

Articles

We have undertaken an HST Space Telescope Imaging Spectrograph survey of 54 late type spiral galaxies to study the scaling relations between black holes and their host spheroids at the low mass end. Our aim is to measure black hole masses or to set upper limits for a sizeable sample of spiral galaxies. In this paper we present new Space Telescope Imaging Spectrograph (STIS) observations of three spiral galaxies, NGC 4303, NGC 3310 and NGC 4258. The bright optical emission lines Hα λ 6564Å, [NII] λλ 6549, 6585Å and [SII] λλ 6718, 6732Å were used to study the kinematics of …

Large Merger Recoils And Spin Flips From Generic Black-Hole Binaries, Manuela Campanelli, Carlos O. Lousto, Yosef Zlochower, David Merritt

Articles

We report the first results from evolutions of generic black-hole binaries, i.e. a binary containing unequal mass black holes with misaligned spins. Our configuration, which has a mass ratio of 2 : 1, consists of an initially non-spinning hole orbiting a larger, rapidly spinning hole (specific spin a/m = 0.885), with the spin direction oriented −45◦ with respect to the orbital plane. We track the inspiral and merger for ∼ 2 orbits and find that the remnant receives a substantial kick of 454 kms−1, more than twice as large as the maximum kick from non-spinning binaries. The remnant spin direction …

Parallel Java: A Unified Api For Shared Memory And Cluster Parallel Programming In 100% Java, Alan Kaminsky

Articles

Parallel Java is a parallel programming API whose goals are (1) to support both shared memory (thread-based) parallel programming and cluster (message-based) parallel programming in a single unified API, allowing one to write parallel programs combining both paradigms; (2) to provide the same capabilities as OpenMP and MPI in an object oriented, 100% Java API; and (3) to be easily deployed and run in a heterogeneous computing environment of single-core CPUs, multi-core CPUs, and clusters thereof. This paper describes Parallel Java’s features and architecture; compares and contrasts Parallel Java to other Java based parallel middleware libraries; and reports performance measurements …

Collisionally Regenerated Dark Matter Structures In Galactic Nuclei, David Merritt, Stefan Harfst, Bertone Gianfranco

Articles

We show that the presence of a r−3/2 dark matter overdensity can be robustly predicted at the center of any galaxy old enough to have grown a power-law density cusp in the stars via the Bahcall-Wolf mechanism. Using both Fokker-Planck and direct N-body integrations, we demonstrate collisional generation of these dark matter “crests” (Collisionally REgenerated STtructures) even in the extreme case that the density of both stars and dark matter were previously lowered by slingshot ejection from a binary supermassive black hole. The time scale for collisional growth of the crest is approximately the two-body relaxation time as defined by …

A New Application For Displaying And Fusing Multimodal Data Sets, Karl Baum, María Helguera, Andrzej Krol

Articles

A recently developed, freely available, application specifically designed for the visualization of multimodal data sets is presented. The application allows multiple 3D data sets such as CT (x-ray computer tomography), MRI (magnetic resonance imaging), PET (positron emission tomography), and SPECT (single photon emission tomography) of the same subject to be viewed simultaneously. This is done by maintaining synchronization of the spatial location viewed within all modalities, and by providing fused views of the data where multiple data sets are displayed as a single volume. Different options for the fused views are provided by plug-ins. Plug-ins typically used include color-overlays and …

The Acs Virgo Cluster Survey. Xiii. Sbf Distance Catalog And The Three-Dimensional Structure Of The Virgo Cluster, Simona Mei, John P. Blakeslee, Patrick Côté, John L. Tonry, Michael J. West, Laura Ferrarese, Andrés Jordán, Eric W. Peng, André Anthony, David Merritt

Articles

The ACS Virgo Cluster Survey consists of HST/ACS imaging for 100 early–type galaxies in the Virgo cluster, observed in the F475W(≈ SDSS g) and F850LP (≈ SDSS z) filters. We derive distances for 84 of these galaxies using the method of Surface Brightness Fluctuations (SBF), present the SBF distance catalog, and use this database to examine the three-dimensional distribution of early–type galaxies in the Virgo Cluster. The SBF distance moduli have a mean (random) measurement error of 0.07 mag (0.5 Mpc), or roughly three times better than previous SBF measurements for Virgo Cluster galaxies. Five galaxies lie at a distance …