Resource integration using a large knowledge base in Carnot

A method for integrating separately developed information resources that overcomes incompatibilities in syntax and semantics and permits the resources to be accessed and modified coherently is described. The method provides logical connectivity among the information resources via a semantic service layer that automates the maintenance of data integrity and provides an approximation of global data integration across systems. This layer is a fundamental part of the Carnot architecture, which provides tools for interoperability across global enterprises     

Comparative influence of repeated measurement and of attention on evoked otoacoustic emissions

This study compared the influence of an auditory attention task and of repetitive measures on the peripheral auditory system, using evoked otoacoustic emissions (EOAEs). The experimental task protocol comprised three sessions (pre-control, attention and post-control conditions) with, in each session, six measurements of EOAEs, at intervals of about 60 seconds, while the other ear was receiving two pure tones of 2,500 and 750 Hz, with a probability of appearance of 20% and 80%, respectively. In the contralateral attention condition, the subject had to count the number of the less frequent high pitched sounds. A long duration protocol (20 min for the total experiment) was used in order to examine a possible time-effect on EOAEs. An increase in EOAE amplitude during the second and third sessions, with linear saturation around the last measurements, was observed. While no attention effect could be identified, a time-effect seemed to be present. Possible explanations for the influence of repeated measurements on EOAEs are discussed. Moreover, EOAE amplitudes of subjects presenting spontaneous otoacoustic emissions were compared to those of subjects without SOAEs: significant differences were found, showing the particularity of cochleas emitting SOAEs.     

Functional maturation of cochlear active mechanisms and of the medial olivocochlear system in humans

The aim of this study was to investigate the functional development of cochlear active mechanisms and of the medial efferent olivocochlear system. Otoacoustic emissions (evoked and spontaneous) were recorded in 42 preterm neonates (conceptional age ranging form 33 to 39 weeks) and a control group of 20 young normal-hearing adults. Medial olivocochlear system activity was examined by coupling evoked otoacoustic emission recording to a contralateral stimulation. Otoacoustic emission recordings were carried out using the Otodynamic ILO88 software and hardware. The stimuli were unfiltered clicks and the contralateral stimulation was broad band noise of 50 and 70 dBSPL delivered by an Adam generator. The results revealed the presence of EOAEs and SOAEs from at least 33 weeks in humans, suggesting that the functional maturation of the outer hair cells is nearly complete at that age. The study further revealed that the contralateral stimulation had no effect on evoked otoacoustic emissions in preterm neonates. The lack of activity observed in medial olivocochlear system indicated functional immaturity here, at least before full-term birth.     

A unified framework for peak detection and alignment: application to HR-MAS 2D NMR spectroscopy

In this paper, we propose a new scheme to detect and align simultaneously peaks that correspond to different metabolites within a biopsy. The proposed peak detection and alignment scheme is based on the use of evidence theory, which is well suited to model uncertainty and imprecision characterizing the 2D NMR HR-MAS spectra. Consequently, we propose the coupling use of Bayesian and fuzzy set theories to model and quantify the imprecision degree, which is then exploited to define the mass function. We particularly show that our new mass function definition and the use of evidence theory for peak detection and alignment achieve consistently high performance compared to a Bayesian scheme on both synthetic and real spectra. The high quality of peak alignment precision reached by the use of evidence theory allows us to efficiently detect reliable biomarkers, which is an essential step for a better therapeutic and human complement system management in case of multiple sclerosis disease, cancer, etc.     

Contralateral suppression of transiently evoked otoacoustic emissions by harmonic complex tones in humans

Variations in the amplitude of transiently evoked otoacoustic emissions (TEOAEs) produced by a contralateral complex tone were measured in 26 normal-hearing human subjects. TEOAEs were evoked using a 1-kHz tone pip at 60 dB SPL. The contralateral complex consisted of harmonic components with frequencies between 400 and 2000 Hz; it was presented at levels ranging from 40 to 50 dB SL and its fundamental frequency (F0) was varied. In experiment 1, the dependence of TEOAE amplitude variations on the F0 of the contralateral complex was measured by varying the F0 from 50 to 400 Hz in octave steps. The results revealed a nonmonotonic dependence of TEOAE amplitude variations on contralateral F0, with significantly larger TEOAE suppression for F0's of 100 and 200 Hz than for F0's of 50 and 400 Hz. Experiment 2, in which the harmonics were summed in alternating sine-cosine phase instead of constant sine phase, showed a shift of the function relating TEOAE attenuation to F0 towards lower F0's, indicating that the waveform repetition rate, rather than harmonic spacing, was the actual factor of the dependence of contralateral TEOAE attenuation on F0. Furthermore, significantly smaller suppression was observed with the alternating-phase complexes than with the sine-phase complexes, suggesting an influence of the waveform crest factor. Experiment 3 showed no difference between the contralateral TEOAE attenuation effects produced by positive and negative Schroeder-phase complexes. Overall, these results bring further arguments for the notion that contralaterally induced medial olivocochlear bundle (MOCB) activity, as measured through the contralateral suppression of TEOAEs in humans, is sensitive to the rate of temporal envelope fluctuations of the contralateral stimulus, with preferential rates around 100-200 Hz.     

Piezoelectric Love waves on rotated Y-cut mm2 substrates

Consider a layer consisting of a m3m dielectric crystal, with faces cut parallel to a symmetry plane. Then bond it onto a semi-infinite mm2 piezoelectric substrate. For a X- or Y-cut of the substrate, a Love wave can propagate in the resulting structure and the corresponding dispersion equation is derived analytically. It turns out that when the upper (free) face of the layer is metalized, a fully explicit treatment can also be conducted in the case of a Y-cut rotated about Z. In the case of a germanium layer over a potassium niobate substrate, the wave exists at any wavelength for X-and Y-cuts but this ceases to be the case for rotated cuts, with the appearance of forbidden ranges. By playing on the cut angle, the Love wave can be made to travel faster than, or slower than, or at the same speed as, the shear bulk wave of the layer. A by-product of the analysis is the derivation of the explicit secular equation for the Bleustein-Gulyaev wave in the substrate alone, which corresponds to an asymptotic behavior of the Love wave. The results are valid for other choices for the layer and for the substrate, provided they have the same, or more, symmetries.     

Ellipsometric and Rutherford Back scattering Spectrometry studies of SiO(X)N(Y) films elaborated by plasma-enhanced chemical vapour deposition technique

Silicon oxynitride (SiO(X)N(Y)) thin films were deposited by plasma-enhanced chemical vapour deposition technique (PECVD) from silane (SiH4), nitrous oxide (N2O), ammonia (NH3) and nitrogen (N2) mixture. Spectroscopic ellipsometry (SE), in the range of wavelengths 450-900 nm, was used to define the film thickness and therefore the deposition rate, as well as the refractive index as a function of the N2O gaseous flow. While considering the (Si3N4, SiO2, H2 or void) heterogeneous mixture, Maxwell Garnett (MG) theory allows to fit the SE measurements and to define the volume fraction of the different phases. Finally, Rutherford Backscattering Spectrometry (RBS) results showed that x = O/Si ratio increases gradually with increasing the N2O flow, allowing the correlation of the SiO(X)N(Y) films main parameters.     

Vitamin D intestinal absorption is not a simple passive diffusion: evidences for involvement of cholesterol transporters

Scope : It is assumed that vitamin D is absorbed by passive diffusion. However, since cholecalciferol (vitamin D₃) and cholesterol display similar structures, we hypothesized that common absorption pathways may exist. Methods and results : Cholecalciferol apical transport was first examined in human Caco‐2 and transfected Human embryonic kidney (HEK) cells. Cholecalciferol uptake was then valuated ex vivo and in vivo, using either wild‐type mice, mice overexpressing Scavenger Receptor class B type I (SR‐BI) at the intestinal level or mice treated or not with ezetimibe. Cholecalciferol uptake was concentration‐, temperature‐ and direction‐dependent, and was significantly impaired by a co‐incubation with cholesterol or tocopherol in Caco‐2 cells. Moreover Block Lipid Transport‐1 (SR‐BI inhibitor) and ezetimibe glucuronide (Niemann‐Pick C1 Like 1 inhibitor) significantly decreased cholecalciferol transport. Transfection of HEK cells with SR‐BI, Cluster Determinant 36 and Niemann‐Pick C1 Like 1 significantly enhanced vitamin D uptake, which was significantly decreased by the addition of Block Lipid Transport‐1, sulfo‐N‐succinimidyl oleate (Cluster Determinant 36 inhibitor) or ezetimibe glucuronide, respectively. Similar results were obtained in mouse intestinal explants. In vivo, cholecalciferol uptake in proximal intestinal fragments was 60% higher in mice overexpressing SR‐BI than in wild‐type mice (p<0.05), while ezetimibe effect remained non‐significant. Conclusion: These data show for the first time that vitamin D intestinal absorption is not passive only but involves, at least partly, some cholesterol transporters.