On Usable Speech Detection by Linear Multi-Scale Decomposition for Speaker Identification

Usable speech is a novel concept of processing co-channel speech data. It is proposed to extract minimally corrupted speech that is considered useful for various speech processing systems. In this paper, we are interested for co-channel speaker identification (SID). We employ a new proposed usable speech extraction method based on the pitch information obtained from linear multi-scale decomposition by discrete wavelet transform. The idea is to retain the speech segments that have only one pitch detected and remove the others. Detected Usable speech was used as input for speaker identification system. The system is evaluated on co-channel speech and results show a significant improvement across various Target to Interferer Ratio (TIR) for speaker identification system

Comparative study between adsorbents based on magnetic nanoferrite. Application to the removal of methyl orange from wastewater

Magnetic ferrite (Mg-doped bismuth ferrite) and its clay-based composite (Mg-doped bismuth ferrite-bentonite) were prepared by self-combustion method utilizing glycine as fuel and served for the removal of methyl orange (MO) from aqueous solutions. The ferrite-based adsorbents were characterized by the measurement of specific surface area (BET), scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD). The different experimental parameters that affect the performance of this reaction such as: temperature, contact time, initial dye concentration and mass of adsorbent were investigated. The point of zero charge pH (pHPZC) was determined for the two adsorbents. Langmuir and Freundlich adsorption models were employed to provide a description of the equilibrium isotherms. Adsorption tests showed that the equilibrium time is a function of the initial concentration of dye. The adsorption kinetic study indicated that the equilibrium adsorption is established after 300 minutes for Mg-doped bismuth ferrite, while it is established after 180 minutes for Mg-doped bismuth ferrite-bentonite composite. Furthermore, this suggests that the adsorption of MO on both adsorbents can be perfectly described by pseudo-second order kinetics. The maximum adsorption capacity determined by the mathematical model of Langmuir is equal to 181.8 mg.g-1 for Mg-doped bismuth ferrite and to 188.7 mg.g-1 for its composite, at 298 K. Adsorption isotherms shows that the Freundlich model perfectly represents adsorption of methyl orange to the prepared Mg-doped bismuth ferrite. The ferrite/bentonite composite has 2-50 nm-sized pores and is indeed a mesoporous material. The small pores observed on the surface of the adsorbents are in line with type IV isotherm, with possible capillary condensation of the adsorbate. Moreover, Langmuir model seems to be the most suitable model for the absorption of methyl orange on the Mg-doped bismuth ferrite-bentonite composite. The thermodynamic parameters related to the sorbent/adsorbate system indicate that adsorption is spontaneous and exothermic. The determination of isosteric heat of adsorption suggested that it is indeed a physisorption characterized by weak intermolecular forces between MO and the surface

Optical Properties of Photobleached DAST Molecular Crystals in Terahertz Domain

International audienceWe demonstrate a one-step fabrication method to realize desired gold (Au) nanoholes arrays by using a one-photon absorption based direct laser writing technique. Thanks to the optically induced thermal effect of Au material at 532 nm excitation wavelength, the local temperature at the laser focus area can reach as high as 600°C, which induces an evaporation of the Au thin film resulting in a metallic nanohole. By controlling the laser spot movement and exposure time, different two-dimensional Au nanoholes structures with periodicity as small as 500 nm have been demonstrated. This allows obtaining plasmonic nanostructures in a single step without needing the preparation of polymeric template and lift-off process. By this direct fabrication technique, the nanoholes do not have circular shape as the laser focusing spot, due to the non-uniform heat transfer in a no-perfect flat Au film. However, the FDTD simulation results and the experimental measurement of the transmission spectra show that the properties of fabricated plasmonic nanoholes arrays are very close to those of ideal plasmonic nanostructures. Actually, the plasmonic resonance depends strongly on the periodicity of the metallic structures while the heterogeneous form of the holes simply enlarges the resonant peak. Furthermore, it is theoretically demonstrated that the non-perfect circular shape of the Au hole allows amplifying the electromagnetic field of the resonant peak by several times as compared to the case of perfect circular shape. This could be an advantage for application of this fabricated structure in laser and nonlinear optics domains

Physicochemical properties and structural studies of a new hybrid compound potassium nitrate-ninhydrin: Promising material for nonlinear applications

International audienc

Molecular Regulation of Canalicular ABC Transporters

International audienceThe ATP-binding cassette (ABC) transporters expressed at the canalicular membrane of hepatocytes mediate the secretion of several compounds into the bile canaliculi and therefore play a key role in bile secretion. Among these transporters, ABCB11 secretes bile acids, ABCB4 translocates phosphatidylcholine and ABCG5/G8 is responsible for cholesterol secretion, while ABCB1 and ABCC2 transport a variety of drugs and other compounds. The dysfunction of these transporters leads to severe, rare, evolutionary biliary diseases. The development of new therapies for patients with these diseases requires a deep understanding of the biology of these transporters. In this review, we report the current knowledge regarding the regulation of canalicular ABC transporters' folding, trafficking, membrane stability and function, and we highlight the role of molecular partners in these regulating mechanisms

MRCK-Alpha and Its Effector Myosin II Regulatory Light Chain Bind ABCB4 and Regulate Its Membrane Expression

ABCB4, is an adenosine triphosphate-binding cassette (ABC) transporter localized at the canalicular membrane of hepatocytes, where it mediates phosphatidylcholine secretion into bile. Gene variations of ABCB4 cause different types of liver diseases, including progressive familial intrahepatic cholestasis type 3 (PFIC3). The molecular mechanisms underlying the trafficking of ABCB4 to and from the canalicular membrane are still unknown. We identified the serine/threonine kinase Myotonic dystrophy kinase-related Cdc42-binding kinase isoform α (MRCKα) as a novel partner of ABCB4. The role of MRCKα was explored, either by expression of dominant negative mutant or by gene silencing using the specific RNAi and CRISPR-cas9 strategy in cell models. The expression of a dominant-negative mutant of MRCKα and MRCKα inhibition by chelerythrine both caused a significant increase in ABCB4 steady-state expression in primary human hepatocytes and HEK-293 cells. RNA interference and CRISPR-Cas9 knockout of MRCKα also caused a significant increase in the amount of ABCB4 protein expression. We demonstrated that the effect of MRCKα was mediated by its downstream effector, the myosin II regulatory light chain (MRLC), which was shown to also bind ABCB4. Our findings provide evidence that MRCKα and MRLC bind to ABCB4 and regulate its cell surface expression