Calculating the inherent visual structure of a landscape ('total viewshed') using high-throughput computing

This paper describes a method of calculating the inherent visibility at all locations in a landscape (‘total viewshed’) by making use of redundant computer cycles. This approach uses a simplified viewshed program that is suitable for use within a distributed environment, in this case managed by the Condor system. Distributing the calculation in this way reduced the calculation time of our example from an estimated 34 days to slightly over 25 hours using a cluster of 43 workstations. Finally, we discuss the example ‘total viewshed’ raster for the Avebury region, and briefly highlight some of its implications

Aggregation of plasma Z type α1-antitrypsin suggests basic defect for the deficiency

AbstractThe abnormal type of α1-antitrypsin, PI (protease inhibitor) type Z, is associated with inclusion bodies in the liver, which contain non-secreted α1-antitrypsin. Our studies show that Z protein has an inherent tendency to aggregate, even in plasma. Depending upon conditions, from 15 to 70% of the Z protein in plasma was in a high-Mr form, compared with 1.5% of M type α1-antitrypsin. The high-Mr complex in plasma cannot be disaggregated using Triton X detergent or reducing conditions. This increased tendency to aggregate can be explained by the mutation affecting, tertiary structure and salt bridge formation in Z protein. We have observed this same tendency to aggregate for Mmalton α1-antitrypsin, a rarer variant also associated with a plasma deficiency

Co2MnSi:Pt multilayers for giant spin Seebeck devices

The spin Seebeck effect (SSE) has been widely studied as a potential mechanism for energy harvesting. However, the efficiency of such devices, utilizing the spin thermoelectric effect in thin film form, has not yet reached a sufficient value to make them economically viable. It is therefore imperative that advances are made to investigate means by which the thermoelectric signal can be enhanced. Multilayers of Co2MnSi and Pt are fabricated and characterized in an attempt to observe enhanced voltages. We report that bilayers of ferromagnetic conductor/normal metal (FM/NM) exhibit a Longitudinal SSE response and that repetitive stacking of such bilayers results in an increased thermoelectric voltage that is highly dependent upon the quality of CMS/Pt and Pt/CMS interfaces

Healthcare-associated outbreak of meticillin-resistant Staphylococcus aureus bacteraemia: role of a cryptic variant of an epidemic clone

BACKGROUND New strains of meticillin-resistant Staphylococcus aureus (MRSA) may be associated with changes in rates of disease or clinical presentation. Conventional typing techniques may not detect new clonal variants that underlie changes in epidemiology or clinical phenotype. AIM To investigate the role of clonal variants of MRSA in an outbreak of MRSA bacteraemia at a hospital in England. METHODS Bacteraemia isolates of the major UK lineages (EMRSA-15 and -16) from before and after the outbreak were analysed by whole-genome sequencing in the context of epidemiological and clinical data. For comparison, EMRSA-15 and -16 isolates from another hospital in England were sequenced. A clonal variant of EMRSA-16 was identified at the outbreak hospital and a molecular signature test designed to distinguish variant isolates among further EMRSA-16 strains. FINDINGS By whole-genome sequencing, EMRSA-16 isolates during the outbreak showed strikingly low genetic diversity (P < 1 × 10(-6), Monte Carlo test), compared with EMRSA-15 and EMRSA-16 isolates from before the outbreak or the comparator hospital, demonstrating the emergence of a clonal variant. The variant was indistinguishable from the ancestral strain by conventional typing. This clonal variant accounted for 64/72 (89%) of EMRSA-16 bacteraemia isolates at the outbreak hospital from 2006. CONCLUSIONS Evolutionary changes in epidemic MRSA strains not detected by conventional typing may be associated with changes in disease epidemiology. Rapid and affordable technologies for whole-genome sequencing are becoming available with the potential to identify and track the emergence of variants of highly clonal organisms

The Hubbard Model at Infinite Dimensions: Thermodynamic and Transport Properties

We present results on thermodynamic quantities, resistivity and optical conductivity for the Hubbard model on a simple hypercubic lattice in infinite dimensions. Our results for the paramagnetic phase display the features expected from an intuitive analysis of the one-particle spectra and substantiate the similarity of the physics of the Hubbard model to those of heavy fermion systems. The calculations were performed using an approximate solution to the single-impurity Anderson model, which is the key quantity entering the solution of the Hubbard model in this limit. To establish the quality of this approximation we compare its results, together with those obtained from two other widely used methods, to essentially exact quantum Monte Carlo results.Comment: 29 pages, 16 figure

The design of a project to assess bilateral versus unilateral hearing aid fitting

Binaural hearing provides advantages over monaural in several ways, particularly in difficult listening situations. For a person with bilateral hearing loss, the bilateral fitting of hearing aids thus seems like a natural choice. However, surprisingly few studies have been reported in which the additional benefit of bilateral versus unilateral hearing aid use has been investigated based on real-life experiences. Therefore, a project has been designed to address this issue and to find tools to identify people for whom the drawbacks would outweigh the advantages of bilateral fitting. A project following this design is likely to provide reliable evidence concerning differences in benefit between unilateral and bilateral fitting of hearing aids by evaluating correlations between entrance data and outcome measures and final preferences

An ergodic theorem of a parabolic Anderson model driven by Lévy noise

In this paper, we study an ergodic theorem of a parabolic Andersen model driven by Lévy noise. Under the assumption that A = (a(i, j))i,j∈S is symmetric with respect to a σ-finite measure gp, we obtain the long-time convergence to an invariant probability measure νh starting from a bounded nonnegative A-harmonic function h based on self-duality property. Furthermore, under some mild conditions, we obtain the one to one correspondence between the bounded nonnegative A-harmonic functions and the extremal invariant probability measures with finite second moment of the nonnegative solution of the parabolic Anderson model driven by Lévy noise, which is an extension of the result of Y. Liu and F. X. Yang

On-disk coronal rain

Small and elongated, cool and dense blob-like structures are being reported with high resolution telescopes in physically different regions throughout the solar atmosphere. Their detection and the understanding of their formation, morphology and thermodynamical characteristics can provide important information on their hosting environment, especially concerning the magnetic field, whose understanding constitutes a major problem in solar physics. An example of such blobs is coronal rain, a phenomenon of thermal non- equilibrium observed in active region loops, which consists of cool and dense chromospheric blobs falling along loop-like paths from coronal heights. So far, only off-limb coronal rain has been observed and few reports on the phenomenon exist. In the present work, several datasets of on-disk H{\alpha} observations with the CRisp Imaging SpectroPolarimeter (CRISP) at the Swedish 1-m Solar Telescope (SST) are analyzed. A special family of on-disk blobs is selected for each dataset and a statistical analysis is carried out on their dynamics, morphology and temperatures. All characteristics present distributions which are very similar to reported coronal rain statistics. We discuss possible interpretations considering other similar blob-like structures reported so far and show that a coronal rain interpretation is the most likely one. Their chromospheric nature and the projection effects (which eliminate all direct possibility of height estimation) on one side, and their small sizes, fast dynamics, and especially, their faint character (offering low contrast with the background intensity) on the other side, are found as the main causes for the absence until now of the detection of this on-disk coronal rain counterpart.Comment: 18 pages, 10 figures. Accepted for Solar Physic

Experimental Facilities Development

This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

Observation of the astrophysically important 3+ state in 18Ne via elastic scattering of a radioactive 17F beam from 1H

The 17F(p, γ)18 reaction is important in stellar explosions, but its rate has been uncertain because of an expected 3+ state in 18Ne that has never been conclusively observed. This state would provide a strong l = 0 resonance and, depending on its excitation energy, could dominate the stellar reaction rate. We have observed this missing 3+ state by measuring the 1H(17F, p)17F excitation function with a radioactive 17F beam at the ORNL Holifield Radioactive Ion Beam Facility. We find that the state lies at a center-of-mass energy of Er = 599.8 ± 1.5stat ± 2.0sys keV (Ex = 4523.7 ± 2.9keV) and has a width of Γ = 18 ± 2stat ± 1sys keV