3,295 research outputs found
A Coverage Criterion for Spaced Seeds and its Applications to Support Vector Machine String Kernels and k-Mer Distances
Spaced seeds have been recently shown to not only detect more alignments, but
also to give a more accurate measure of phylogenetic distances (Boden et al.,
2013, Horwege et al., 2014, Leimeister et al., 2014), and to provide a lower
misclassification rate when used with Support Vector Machines (SVMs) (On-odera
and Shibuya, 2013), We confirm by independent experiments these two results,
and propose in this article to use a coverage criterion (Benson and Mak, 2008,
Martin, 2013, Martin and No{\'e}, 2014), to measure the seed efficiency in both
cases in order to design better seed patterns. We show first how this coverage
criterion can be directly measured by a full automaton-based approach. We then
illustrate how this criterion performs when compared with two other criteria
frequently used, namely the single-hit and multiple-hit criteria, through
correlation coefficients with the correct classification/the true distance. At
the end, for alignment-free distances, we propose an extension by adopting the
coverage criterion, show how it performs, and indicate how it can be
efficiently computed.Comment: http://online.liebertpub.com/doi/abs/10.1089/cmb.2014.017
The fast transient sky with Gaia
The ESA Gaia satellite scans the whole sky with a temporal sampling ranging
from seconds and hours to months. Each time a source passes within the Gaia
field of view, it moves over 10 CCDs in 45 s and a lightcurve with 4.5 s
sampling (the crossing time per CCD) is registered. Given that the 4.5 s
sampling represents a virtually unexplored parameter space in optical time
domain astronomy, this data set potentially provides a unique opportunity to
open up the fast transient sky. We present a method to start mining the wealth
of information in the per CCD Gaia data. We perform extensive data filtering to
eliminate known on-board and data processing artefacts, and present a
statistical method to identify sources that show transient brightness
variations on ~2 hours timescales. We illustrate that by using the Gaia
photometric CCD measurements, we can detect transient brightness variations
down to an amplitude of 0.3 mag on timescales ranging from 15 seconds to
several hours. We search an area of ~23.5 square degrees on the sky, and find
four strong candidate fast transients. Two candidates are tentatively
classified as flares on M-dwarf stars, while one is probably a flare on a giant
star and one potentially a flare on a solar type star. These classifications
are based on archival data and the timescales involved. We argue that the
method presented here can be added to the existing Gaia Science Alerts
infrastructure for the near real-time public dissemination of fast transient
events.Comment: 10 pages, 5 figures and 5 tables; MNRAS in pres
Micro-cracks detection in Photo-Voltaic Cells by Infrared Thermography
Abstract In this paper, a technique is presented to detect micro-cracks on photo-voltaic cells by infrared thermography. The originality of the system comes from the thermoelectric stimulation used to generate thermal transients at micro-crack locations. These thermal transient are picked-up by an infrared cameras for further detection
Burn Center Organization and Cellular Therapy Integration: Managing Risks and Costs.
The complex management of severe burn victims requires an integrative collaboration of multidisciplinary specialists in order to ensure quality and excellence in healthcare. This multidisciplinary care has quickly led to the integration of cell therapies in clinical care of burn patients. Specific advances in cellular therapy together with medical care have allowed for rapid treatment, shorter residence in hospitals and intensive care units, shorter durations of mechanical ventilation, lower complications and surgery interventions, and decreasing mortality rates. However, naturally fluctuating patient admission rates increase pressure toward optimized resource utilization. Besides, European translational developments of cellular therapies currently face potentially jeopardizing challenges on the policy front. The aim of the present work is to provide key considerations in burn care with focus on architectural and organizational aspects of burn centers, management of cellular therapy products, and guidelines in evolving restrictive regulations relative to standardized cell therapies. Thus, based on our experience, we present herein integrated management of risks and costs for preserving and optimizing clinical care and cellular therapies for patients in dire need
Tomography of Galactic star-forming regions and spiral arms with the Square Kilometer Array
© 2014 Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence https://creativecommons.org/licenses/by-nc-sa/3.0/us/. Published by Proceedings of Science http://pos.sissa.it/Very Long Baseline Interferometry (VLBI) at radio wavelengths can provide astrometry accurate to 10 micro-arcseconds or better (i.e. better than the target GAIA accuracy) without being limited by dust obscuration. This means that unlike GAIA, VLBI can be applied to star-forming regions independently of their internal and line-of-sight extinction. Low-mass young stellar objects (particularly T Tauri stars) are often non-thermal compact radio emitters, ideal for astrometric VLBI radio continuum experiments. Existing observations for nearby regions (e.g. Taurus, Ophiuchus, or Orion) demonstrate that VLBI astrometry of such active T Tauri stars enables the reconstruction of both the regions' 3D structure (through parallax measurements) and their internal kinematics (through proper motions, combined with radial velocities). The extraordinary sensitivity of the SKA telescope will enable similar "tomographic mappings" to be extended to regions located several kpc from Earth, in particular to nearby spiral arm segments. This will have important implications for Galactic science, galactic dynamics and spiral structure theories
Development of Red Flags Index for Early Referral of Adults with Symptoms and Signs Suggestive of Crohn's Disease: An IOIBD Initiative
International audience; BACKGROUND AND AIMS:Diagnostic delay is frequent in patients with Crohn's disease (CD). We developed a tool to predict early diagnosis.METHODS:A systematic literature review and 12 CD specialists identified 'Red Flags', i.e. symptoms or signs suggestive of CD. A 21-item questionnaire was administered to 36 healthy subjects, 80 patients with irritable bowel syndrome (non-CD group) and 85 patients with recently diagnosed (<18 months) CD. Patients with CD were asked to recall symptoms and signs they experienced during the 12 months before diagnosis. Multiple logistic regression analyses selected and weighted independent items to construct the Red Flags index. A receiver operating characteristic curve was used to assess the threshold that discriminated CD from non-CD. Association with the Red Flags index relative to this threshold was expressed as the odds ratios (OR).RESULTS:Two hundred and one subjects, CD and non-CD, answered the questionnaire. The multivariate analysis identified eight items independently associated with a diagnosis of CD. A minimum Red Flags index value of 8 was highly predictive of CD diagnosis with sensitivity and specificity bootstrap estimates of 0.94 (95% confidence interval 0.88-0.99) and 0.94 (0.90-0.97), respectively. Positive and negative likelihood ratios were 15.1 (9.3-33.6) and 0.066 (0.013-0.125), respectively. The association between CD diagnosis and a Red Flags index value of ≥8 corresponds to an OR of 290 (p < 0.0001).CONCLUSIONS:The Red Flags index using early symptoms and signs has high predictive value for the diagnosis of CD. These results need prospective validation prior to introduction into clinical practice
Quantum Dash Actively Mode-locked Fabry-Perot Laser Module demonstrated as part of a Wavelength Tunable RZ Transmitter
International audienceA quantum dash Fabry-Perot actively modelocked laser module is tested as part of a 42.7 Gbit/s transmitter with more than 10 nm wavelength tunability. Its low chirp level is also assessed through chromatic dispersion tolerance measurements
- …