6,959 research outputs found
Local Density of the Bose Glass Phase
We study the Bose-Hubbard model in the presence of on-site disorder in the
canonical ensemble and conclude that the local density of the Bose glass phase
behaves differently at incommensurate filling than it does at commensurate one.
Scaling of the superfluid density at incommensurate filling of and
on-site interaction predicts a superfluid-Bose glass transition at
disorder strength of . At this filling the local density
distribution shows skew behavior with increasing disorder strength.
Multifractal analysis also suggests a multifractal behavior resembling that of
the Anderson localization. Percolation analysis points to a phase transition of
percolating non-integer filled sites around the same value of disorder. Our
findings support the scenario of percolating superfluid clusters enhancing
Anderson localization near the superfluid-Bose glass transition. On the other
hand, the behavior of the commensurate filled system is rather different. Close
to the tip of the Mott lobe () we find a Mott insulator-Bose
glass transition at disorder strength of . An analysis of
the local density distribution shows Gaussian like behavior for a wide range of
disorders above and below the transition.Comment: 12 pages, 14 figure
An advanced transparent hydropolymer wound dressing for undisturbed postâop management of surgical wounds following hip and knee replacement: A prospective observational series
Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are standardised surgical procedures for patients with complex comorbidities. The enhanced recovery after surgery (ERAS) protocol has shown reduced lengths of hospital stay and reduced postoperative complications. Currently, there is a paucity of recommendations in regards to dressing selection for postoperative wound care within the ERAS protocol. The aim of this study was to investigate the usefulness of a transparent hydropolymer wound dressing in suit for 14âdays in 20 orthopaedic patients following hip or knee arthroplasty under the ERAS protocol. The majority of participants (90%) had a wear time of 14âdays without the need for dressing removal. Clinicians rated the dressing very easy to apply with very good visibility of the incision line (100%). All participants reported the dressing to be âvery comfortableâ (95%, n = 19) or âcomfortableâ (5%, n = 1). Overall, the transparent hydropolymer dressing provided sufficient incision site visibility, reducing the need for dressing changes. To the best of our knowledge, this is the first study to show that the use of a transparent hydropolymer dressing in situ for 14âdays to allow undisturbed wound healing
A burst from the direction of UZ Fornacis with XMM-Newton
The XMM-Newton pointing towards the magnetic cataclysmic variable UZ For
finds the source to be a factor > 10^3 fainter than previous EXOSAT and ROSAT
observations. The source was not detected for the majority of a 22 ksec
exposure with the EPIC cameras, suggesting that the accretion rate either
decreased, or stopped altogether. However a 1.1 ksec burst was detected from UZ
For during the observation. Spectral fits favour optically thin, kT = 4.4 keV
thermal emission. Detection of the burst by the on-board Optical Monitor
indicates that this was most probably an accretion event. The 0.1-10 keV
luminosity of 2.1 x 10^30 erg/s is typical for accretion shock emission from
high state polars and would result from the potential energy release of ~ 10^16
g of gas. There is no significant soft excess due to reprocessing in the white
dwarf atmosphere.Comment: 7 pages, 2 postscript figures, ApJL, in pres
A bremsstrahlung gamma-ray source based on stable ionization injection of electrons into a laser wakefield accelerator
Laser wakefield acceleration permits the generation of ultra-short,
high-brightness relativistic electron beams on a millimeter scale. While those
features are of interest for many applications, the source remains constraint
by the poor stability of the electron injection process. Here we present
results on injection and acceleration of electrons in pure nitrogen and argon.
We observe stable, continuous ionization-induced injection of electrons into
the wakefield for laser powers exceeding a threshold of 7 TW. The beam charge
scales approximately linear with the laser energy and is limited by beam
loading. For 40 TW laser pulses we measure a maximum charge of almost 1 nC per
shot, originating mostly from electrons of less than 10 MeV energy. The
relatively low energy, the high charge and its stability make this source
well-suited for applications such as non-destructive testing. Hence, we
demonstrate the production of energetic radiation via bremsstrahlung conversion
at 1 Hz repetition rate. In accordance with Geant4 Monte-Carlo simulations, we
measure a gamma-ray source size of less than 100 microns for a 0.5 mm tantalum
converter placed at 2 mm from the accelerator exit. Furthermore we present
radiographs of image quality indicators
A Reanalysis of theUltraviolet Extinction from Interstellar Dust in the Large Magellanic Cloud
We have reanalyzed the Large Magellanic Cloud's (LMC) ultraviolet (UV)
extinction using data from the IUE final archive. Our new analysis takes
advantage of the improved signal--to--noise of the IUE NEWSIPS reduction, the
exclusion of stars with very low reddening, the careful selection of well
matched comparison stars, and an analysis of the effects of Galactic foreground
dust. Differences between the average extinction curves of the 30 Dor region
and the rest of the LMC are reduced compared to previous studies. We find that
there is a group of stars with very weak 2175 Ang. bumps that lie in or near
the region occupied by the supergiant shell, LMC 2, on the southeast side of 30
Dor. The average extinction curves inside and outside LMC 2 show a very
significant difference in 2175 Ang. bump strength, but their far--UV
extinctions are similar. While it is unclear whether or not the extinction
outside the LMC 2 region can be fit with the relation of Cardelli, Clayton and
Mathis (CCM), sightlines near LMC 2 cannot be fit with CCM due to their weak
2175 Ang. bumps. While the extinction properties seen in the LMC lie within the
range of properties seen in the Galaxy, the correlations of UV extinction
properties with environment seen in the Galaxy do not appear to hold in the
LMC.Comment: 29 pages, 10 figures, to be published in Ap
Search for emission of unstable Be clusters from hot Ca and Ni nuclei
The possible occurence of highly deformed configurations is investigated in
the Ca and Ni di-nuclear systems as formed in the Si +
C and Si + Si reactions, respectively, by using the
properties of emitted light charged particles. Inclusive as well as exclusive
data of the heavy fragments (A 6) and their associated light charged
particles (p, d, t, and -particles) have been collected at the IReS
Strasbourg VIVITRON Tandem facility with two bombarding energies
Si) = 112 and 180 MeV by using the ICARE charged particle
multidetector array, which consists of nearly 40 telescopes. The measured
energy spectra, velocity distributions, in-plane and out-of-plane angular
correlations are analysed by Monte Carlo CASCADE statistical-model calculations
using a consistent set of parameters with spin-dependent level densities.
Although significant deformation effects at high spin are needed, the remaining
disagreement observed in the Si + C reaction for the S
evaporation residue suggests an unexpected large unstable Be cluster
emission of a binary nature.Comment: 13 pages latex, 9 eps figures. Paper presented at the XXXIX
International Winter Meeting on Nuclear Physics, Bormio(Italy) January 22-27,
2001 (to be published at Ricerca Scientifica ed Educazione Permanente
Visuo-motor transformations in the intraparietal sulcus mediate the acquisition of endovascular medical skill
Performing endovascular medical interventions safely and efficiently requires a diverse set of skills that need to be practised in dedicated training sessions. Here, we used multimodal magnetic resonance (MR) imaging to determine the structural and functional plasticity and core skills associated with skill acquisition. A training group learned to perform a simulator-based endovascular procedure, while a control group performed a simplified version of the task; multimodal MR images were acquired before and after training. Using a well-controlled interaction design, we found strong, multimodal evidence for the role of the intraparietal sulcus (IPS) in endovascular skill acquisition that is in line with previous work implicating the structure in simple visuo-motor and mental rotation tasks. Our results provide a unique window into the multimodal nature of rapid structural and functional plasticity of the human brain while learning a multifaceted and complex clinical skill. Further, our results provide a detailed description of the plasticity process associated with endovascular skill acquisition and highlight specific facets of skills that could enhance current medical pedagogy and be useful to explicitly target during clinical resident training
Combined effect of changing hydroclimate and human activity on coastal ecosystem health. AMORE III (Advanced MOdeling and Research on eutrophication) project
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