509 research outputs found
Multi-layer Architecture For Storing Visual Data Based on WCF and Microsoft SQL Server Database
In this paper we present a novel architecture for storing visual data.
Effective storing, browsing and searching collections of images is one of the
most important challenges of computer science. The design of architecture for
storing such data requires a set of tools and frameworks such as SQL database
management systems and service-oriented frameworks. The proposed solution is
based on a multi-layer architecture, which allows to replace any component
without recompilation of other components. The approach contains five
components, i.e. Model, Base Engine, Concrete Engine, CBIR service and
Presentation. They were based on two well-known design patterns: Dependency
Injection and Inverse of Control. For experimental purposes we implemented the
SURF local interest point detector as a feature extractor and -means
clustering as indexer. The presented architecture is intended for content-based
retrieval systems simulation purposes as well as for real-world CBIR tasks.Comment: Accepted for the 14th International Conference on Artificial
Intelligence and Soft Computing, ICAISC, June 14-18, 2015, Zakopane, Polan
Standardization and validation of a novel and simple method to assess lumbar dural sac size
AimTo develop and validate a simple, reproducible method to assess dural sac size using standard imaging technology.Materials and methodsThis study was institutional review board-approved. Two readers, blinded to the diagnoses, measured anteriorâposterior (AP) and transverse (TR) dural sac diameter (DSD), and AP vertebral body diameter (VBD) of the lumbar vertebrae using MRI images from 53 control patients with pre-existing MRI examinations, 19 prospectively MRI-imaged healthy controls, and 24 patients with Marfan syndrome with prior MRI or CT lumbar spine imaging. Statistical analysis utilized linear and logistic regression, Pearson correlation, and receiver operating characteristic (ROC) curves.ResultsAP-DSD and TR-DSD measurements were reproducible between two readers (r = 0.91 and 0.87, respectively). DSD (L1âL5) was not different between male and female controls in the AP or TR plane (p = 0.43; p = 0.40, respectively), and did not vary by age (p = 0.62; p = 0.25) or height (p = 0.64; p = 0.32). AP-VBD was greater in males versus females (p = 1.5 Ă 10â8), resulting in a smaller dural sac ratio (DSR) (DSD/VBD) in males (p = 5.8 Ă 10â6). Marfan patients had larger AP-DSDs and TR-DSDs than controls (p = 5.9 Ă 10â9; p = 6.5 Ă 10â9, respectively). Compared to DSR, AP-DSD and TR-DSD better discriminate Marfan from control subjects based on area under the curve (AUC) values from unadjusted ROCs (AP-DSD p < 0.01; TR-DSD p = 0.04).ConclusionIndividual vertebrae and L1âL5 (average) AP-DSD and TR-DSD measurements are simple, reliable, and reproducible for quantitating dural sac size without needing to control for gender, age, or height
The Seiberg-Witten Map for a Time-dependent Background
In this paper the Seiberg-Witten map for a time-dependent background related
to a null-brane orbifold is studied. The commutation relations of the
coordinates are linear, i.e. it is an example of the Lie algebra type. The
equivalence map between the Kontsevich star product for this background and the
Weyl-Moyal star product for a background with constant noncommutativity
parameter is also studied.Comment: latex, 13 pages, references added and some misprints correcte
Kinetics of Asymmetric Transfer Hydrogenation, Catalyst Deactivation, and Inhibition with Noyori Complexes As Revealed by Real-Time High-Resolution FlowNMR Spectroscopy
Catalytic
hydrogen transfer from basic isopropyl alcohol to aryl
ketones mediated by [(arene)Â(TsDPEN)ÂRuCl] complexes has been investigated
by operando <sup>1</sup>H NMR spectroscopy using a recirculating flow
setup. Selective excitation pulse sequences allowed fast and quantitative
monitoring of the key [(mesitylene)Â(TsDPEN)ÂRuH] intermediate during
catalysis, which is shown to interact with both substrates by polarization
transfer experiments. Comparison of reaction profiles with catalyst
speciation traces in conjunction with reaction progress kinetic analysis
using variable time normalization and kinetic modeling showed the
existence of two independent catalyst deactivation/inhibition pathways:
whereas excess base exerted a competitive inhibition effect on the
unsaturated catalyst intermediate, the active hydride suffered from
an inherent first-order decay that is not evident in early stages
of the reaction where turnover is fast. Isotopic labeling revealed
arene loss to be the entry point into deactivation pathways to Ru
nanoparticles via hydride-bridged intermediates
Production of asiaticoside and madecasosside in Centella asiatica in vitro and in vivo
The localization was determined of the triterpenoids, asiaticoside and madecassoside, in different organs of glasshousegrown plants and cultured material, including transformed roots, of two phenotypes of Centella asiatica (L.) Urban of Malaysian origin. Methanolic extracts of asiaticoside and madecassoside were prepared for gradient HPLC analysis. The two phenotypes of C. asiatica exhibited differences in terpenoid content that were tissue specific and varied between glasshouse-grown plants and tissue culture-derived material. Terpenoid content was highest in leaves, with asiaticoside (0.79 ± 0.03 and 1.15 ± 0.10 % of dry mass) and madecassoside [0.97 ± 0.06 and 1.65 ± 0.01 %(d.m.)] in the fringed (F) and smooth leaf (S) phenotypes, respectively. Roots of the F-phenotype contained the lowest content of asiaticoside [0.12 ± 0.01 %(d.m.)], whereas petioles of S-phenotype plants contained the lowest content of asiaticoside [0.16 ± 0.01 %(d.m.)] and madecassoside [0.18 ± 0.14 %(d.m.)]. Transformed roots were induced using Agrobacterium rhizogens and their growth was maximal on Murashige and Skoog basal medium supplemented with 60 g dm-3 sucrose. However, asiaticoside and madecassoside were undetectable in transformed roots and undifferentiated callus
The HO Southern Galactic Plane Survey (HOPS) - I. Techniques and HO maser data
The definitive version can be found at: http://onlinelibrary.wiley.com/ Copyright Royal Astronomical SocietyWe present first results of the HO Southern Galactic Plane Survey (HOPS), using the Mopra Radio Telescope with a broad-band backend and a beam size of about 2 arcmin. We have observed 100 deg of the southern Galactic plane at 12mm (19.5-27.5GHz), including spectral line emission from HO masers, multiple metastable transitions of ammonia, cyanoacetylene, methanol and radio recombination lines. In this paper, we report on the characteristics of the survey and HO maser emission. We find 540 HO masers, of which 334 are new detections. The strongest maser is 3933Jy and the weakest is 0.7Jy, with 62 masers over 100Jy. In 14 maser sites, the spread in the velocity of the HO maser emission exceeds 100kms. In one region, the HO maser velocities are separated by 351.3kms. The rms noise levels are typically between 1 and 2Jy, with 95 per cent of the survey under 2Jy. We estimate completeness limits of 98 per cent at around 8.4Jy and 50 per cent at around 5.5Jy. We estimate that there are between 800 and 1500 HO masers in the Galaxy that are detectable in a survey with similar completeness limits to HOPS. We report possible masers in NH (11,9) and (8,6) emission towards G19.61-0.23 and in the NH (3,3) line towards G23.33-0.30.Peer reviewe
Matrix Compactification On Orientifolds
Generalizing previous results for orbifolds, in this paper we describe the
compactification of Matrix model on an orientifold which is a quotient space as
a Yang-Mills theory living on a quantum space. The information of the
compactification is encoded in the action of the discrete symmetry group G on
Euclidean space and a projective representation U of G. The choice of Hilbert
space on which the algebra of U is realized as an operator algebra corresponds
to the choice of a physical background for the compactification. All these data
are summarized in the spectral triple of the quantum space.Comment: 28 pages, late
One-loop Quantum Corrections to the Entropy for an Extremal Reissner-Nordstr\"om Black Hole
The first quantum corrections to the entropy for an eternal 4-dimensional
extremal Reissner-Nordstr\"om black hole is investigated at one-loop level, in
the large mass limit of the black hole, making use of the conformal techniques
related to the optical metric. A leading cubic horizon divergence is found and
other divergences appear due to the singular nature of the optical manifold.
The area law is shown to be violated.Comment: 10 pages, LaTe
The Localization Transition of the Two-Dimensional Lorentz Model
We investigate the dynamics of a single tracer particle performing Brownian
motion in a two-dimensional course of randomly distributed hard obstacles. At a
certain critical obstacle density, the motion of the tracer becomes anomalous
over many decades in time, which is rationalized in terms of an underlying
percolation transition of the void space. In the vicinity of this critical
density the dynamics follows the anomalous one up to a crossover time scale
where the motion becomes either diffusive or localized. We analyze the scaling
behavior of the time-dependent diffusion coefficient D(t) including corrections
to scaling. Away from the critical density, D(t) exhibits universal
hydrodynamic long-time tails both in the diffusive as well as in the localized
phase.Comment: 13 pages, 7 figures
Opsin evolution in the Ambulacraria
Opsins - G-protein coupled receptors involved in photoreception - have been extensively studied in the animal kingdom. The present work provides new insights into opsin-based photoreception and photoreceptor cell evolution with a first analysis of opsin sequence data for a major deuterostome clade, the Ambulacraria. Systematic data analysis, including for the first time hemichordate opsin sequences and an expanded echinoderm dataset, led to a robust opsin phylogeny for this cornerstone superphylum. Multiple genomic and transcriptomic resources were surveyed to cover each class of Hemichordata and Echinodermata. In total, 119 ambulacrarian opsin sequences were found, 22 new sequences in hemichordates and 97 in echinoderms (including 67 new sequences). We framed the ambulacrarian opsin repertoire within eumetazoan diversity by including selected reference opsins from non-ambulacrarians. Our findings corroborate the presence of all major ancestral bilaterian opsin groups in Ambulacraria. Furthermore, we identified two opsin groups specific to echinoderms. In conclusion, a molecular phylogenetic framework for investigating light-perception and photobiological behaviors in marine deuterostomes has been obtained
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