A Search for Correlation of Ultra-High Energy Cosmic Rays with IRAS-PSCz and 2MASS-6dF Galaxies

We study the arrival directions of 69 ultra-high energy cosmic rays (UHECRs) observed at the Pierre Auger Observatory (PAO) with energies exceeding 55 EeV. We investigate whether the UHECRs exhibit the anisotropy signal expected if the primary particles are protons that originate in galaxies in the local universe, or in sources correlated with these galaxies. We cross-correlate the UHECR arrival directions with the positions of IRAS-PSCz and 2MASS-6dF galaxies taking into account particle energy losses during propagation. This is the first time that the 6dF survey is used in a search for the sources of UHECRs and the first time that the PSCz survey is used with the full 69 PAO events. The observed cross-correlation signal is larger for the PAO UHECRs than for 94% (98%) of realisations from an isotropic distribution when cross-correlated with the PSCz (6dF). On the other hand the observed cross-correlation signal is lower than that expected from 85% of realisations, had the UHECRs originated in galaxies in either survey. The observed cross-correlation signal does exceed that expected by 50% of the realisations if the UHECRs are randomly deflected by intervening magnetic fields by 5 degrees or more. We propose a new method of analysing the expected anisotropy signal, by dividing the predicted UHECR source distribution into equal predicted flux radial shells, which can help localise and constrain the properties of UHECR sources. We find that the 69 PAO events are consistent with isotropy in the nearest of three shells we define, whereas there is weak evidence for correlation with the predicted source distribution in the two more distant shells in which the galaxy distribution is less anisotropic.Comment: 23 pages, version published in JCA

Effects of the high-density lipoprotein mimetic agent CER-001 on coronary atherosclerosis in patients with acute coronary syndromes: a randomized trial†

Aim High-density lipoproteins (HDLs) have several potentially protective vascular effects. Most clinical studies of therapies targeting HDL have failed to show benefits vs. placebo. Objective To investigate the effects of an HDL-mimetic agent on atherosclerosis by intravascular ultrasonography (IVUS) and quantitative coronary angiography (QCA). Design and setting A prospective, double-blinded, randomized trial was conducted at 51 centres in the USA, the Netherlands, Canada, and France. Intravascular ultrasonography and QCA were performed to assess coronary atherosclerosis at baseline and 3 (2-5) weeks after the last study infusion. Patients Five hundred and seven patients were randomized; 417 and 461 had paired IVUS and QCA measurements, respectively. Intervention Patients were randomized to receive 6 weekly infusions of placebo, 3 mg/kg, 6 mg/kg, or 12 mg/kg CER-001. Main outcome measures The primary efficacy parameter was the nominal change in the total atheroma volume. Nominal changes in per cent atheroma volume on IVUS and coronary scores on QCA were also pre-specified endpoints. Results The nominal change in the total atheroma volume (adjusted means) was −2.71, −3.13, −1.50, and −3.05 mm3 with placebo, CER-001 3 mg/kg, 6 mg/kg, and 12 mg/kg, respectively (primary analysis of 12 mg/kg vs. placebo: P = 0.81). There was also no difference among groups for the nominal change in per cent atheroma volume (0.02, −0.02, 0.01, and 0.19%; nominal P = 0.53 for 12 mg/kg vs. placebo). Change in the coronary artery score was −0.022, −0.036, −0.022, and −0.015 mm (nominal P = 0.25, 0.99, 0.55), and change in the cumulative coronary stenosis score was −0.51, 2.65, 0.71, and −0.77% (compared with placebo, nominal P = 0.85 for 12 mg/kg and nominal P = 0.01 for 3 mg/kg). The number of patients with major cardiovascular events was 10 (8.3%), 16 (13.3%), 17 (13.7%), and 12 (9.8%) in the four groups. Conclusion CER-001 infusions did not reduce coronary atherosclerosis on IVUS and QCA when compared with placebo. Whether CER-001 administered in other regimens or to other populations could favourably affect atherosclerosis must await further study. Name of the trial registry: Clinicaltrials.gov; Registry's URL: http://clinicaltrials.gov/ct2/show/NCT01201837?term=cer-001&rank=2; Trial registration number: NCT0120183

Highly-parallelized simulation of a pixelated LArTPC on a GPU

The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype

Mass loss from stars and the evolution of stellar clusters: Proceedings of a workshop held at Lunteren, the Netherlands, 29 May-1 June 2006

In the spring of 2006 a four day international workshop was held in Lunteren, The Netherlands, in honor of the formal retirement of Prof. Henny Lamers. These proceedings provide a comprehensive overview of mass loss in massive stars and of the dynamical fate of clusters. The dynamical evolution of clusters is affected by stellar winds, mass loss outbursts and supernova explosions as well as by the loss of stars in dynamical interactions, thus linking the two central themes of the workshop. It is becoming clear that mass loss by radiation pressure on spectral lines is not only at work in normal O, B, and A stars but also in Luminous Blue Variables and Wolf-Rayet stars. The importance of these line-driven winds relative to outbursts in the Luminous Blue Variable phase of evolution is under debate. A central issue in this discussion is the importance of small and possibly large scale structure in stellar winds and its implications for the measured mass loss rates. These proceedings report on progress establishing wind properties, on theoretical predictions of mass loss and wind structure as a function of stellar properties, and on the effects of mass loss on the evolution of massive stars. As a result of dynamical interactions, clusters may dissolve completely over time. Observational studies of cluster dissolution timescales as a function of cluster formation history and cluster and environmental properties, are at the focus of cluster studies in the last decade. A key topic discussed in this book is whether the old globular clusters we observe today were once similar to present-day massive young clusters. The mass function of the two types of clusters is observed to be different. Is this a result of dynamical evoltuion or were the mass functions different at formation? The 12 invited reviews, 18 contributed talks, 48 poster papers, and two discussion sessions combine to provide and in-depth assessment of both observational and theoretical issues. The book is suitable for researchers and graduate students interested in stellar astrophysics and cluster dynamics

Timing of syenite-charnockite magmatism and ruby- and sapphire metamorphism in the Mogok valley region, Myanmar

We thank the Oxford–Burma Aung San Suu Kyi trust for funding research and fieldwork visits to Myanmarfor MS,NG and LR. Geochronology was funded by UCSB and NSF grants EAR-1348003and EAR-1551054.The Mogok metamorphic belt (MMB) extends for over 1,000 km along central Burma from the Andaman Sea to the East Himalayan syntaxis and represents exhumed lower and middle crustal metamorphic rocks of the Sibumasu plate. In the Mogok valley region, the MMB consists of regional high‐grade marbles containing calcite + phlogopite + spinel + apatite ± diopside ± olivine and hosts world class ruby and sapphire gemstones. The coarse‐grained marbles have been intruded by orthopyroxene‐ and clinopyroxene‐bearing charnockite‐syenite sheet‐like intrusions that have skarns around the margins. Syenites range from hornblende‐ to quartz‐bearing and frequently show layering that could be a primary igneous texture or a later metamorphic overprint. Calc‐silicate skarns contain both rubies and blue sapphires with large biotites. Rubies occur in marbles with scapolite, phlogopite, graphite, occasional diopside, and blue apatite. Both marbles and syenites have been intruded by the Miocene Kabaing garnet‐muscovite‐biotite peraluminous leucogranite. New mapping and structural observations combined with U‐Th‐Pb zircon, monazite, and titanite geochronology from syenites, charnockites, leucogranites, meta‐rhyolite‐tuffs, and skarns have revealed a complex multiphase igneous and metamorphic history for the MMB. U‐Pb zircon ages of the charnockite‐syenites fall into three categories, Jurassic (170–168 Ma), latest Cretaceous to early Paleocene (~68‐63 Ma), and late Eocene–Oligocene (44–21 Ma). New ages from five samples suggest that metamorphism in the presence of garnet and melt occurred between ~45 and 24 Ma. U‐Pb titanite ages from the ruby marbles and meta‐skarns at Le Oo mine in the Mogok valley are 21 Ma, similar to titanite ages from an adjacent syenite (22 Ma). U‐Th‐Pb dating shows that all the metamorphic ages are Late Cretaceous–early Miocene and related to the India‐Sibumasu collision.Publisher PDFPeer reviewe

Ultra-deep sequencing provides insights into the virology of hepatitis C super-infections in a case of three sequential infections with different genotypes

The current epidemic of Hepatitis C infection in HIV-positive men who have sex with men is associated with increasing use of recreational drugs. Multiple HCV infections have been reported in haemophiliacs and intravenous drug users. Using ultra-deep sequencing analysis, we present the case of an HIV-positive MSM with evidence of three sequential HCV infections, each occurring during the acute phase of the preceding infection, following risk exposures. We observed rapid replacement of the original strain by the incoming genotype at subsequent time points. The impact of HCV super-infection remains unclear and UDS may provide new insights