Adaptive transform skipping for improved coding of motion compensated residuals

New generations of video compression algorithms, such as those included in the under development High Efficiency Video Coding (HEVC) standard, provide substantially higher compression compared to their ancestors. The gain is achieved by improved prediction of pixels, both within a frame and between frames. Novel coding tools that contribute to the gain provide highly uncorrelated prediction residuals for which classical frequency decomposition methods, such as the discrete cosine transform, may not be able to supply a compact representation with few significant coefficients. To further increase the compression gains, this paper proposes transform skip modes which allow skipping one or both 1-D constituent transforms (i.e., vertical and horizontal), which is more suitable for sparse residuals. The proposed transform skip mode is tested in the HEVC codec and is able to provide bitrate reductions of up to 10% at the same objective quality when compared with the application of 2-D block transforms only. Moreover, the proposed transform skip mode outperforms the full transform skip currently investigated for possible adoption in the HEVC standard.     

Spray-dried nanoparticle-loaded pectin microspheres for dexamethasone nasal delivery

Abstract

In this study, we present the development of an innovative dry powder dexamethasone (Dex) nasal delivery system comprising Dex-loaded lipid/alginate nanoparticles incorporated within pectin microspheres (Dex/NPs-loaded pectin microspheres; DNM). DNM microspheres were characterized by the mean diameter of 2.76?±?0.10?µm, zeta-potential of –36.2?±?1.1?mV, and drug loading of 3.3?±?0.3%. The morphology study revealed irregular microsphere surface forming external voids. In contact with simulated nasal fluid, DNM microspheres demonstrated desirable property of moderate swelling and ensured stronger mucoadhesion compared with conventional Dex-loaded pectin microspheres. The strategy of Dex incorporation within the lipid/alginate NPs resulted in prolonged Dex release in relation to Dex being directly entrapped within the conventional pectin microspheres. DNM microspheres showed excellent biocompatibility and rendered Dex permeation across the selected epithelial cell model similar to that of Dex solution. In conclusion, balanced biopharmaceutical properties of the proposed nasal Dex delivery system provides the potential for prolonged contact time with nasal mucosa, prolonged therapeutic effect, and improved patient compliance.     

Reorganization of the Brain Extracellular Matrix in Hippocampal Sclerosis

The extracellular matrix (ECM) is an important regulator of excitability and synaptic plasticity, especially in its highly condensed form, the perineuronal nets (PNN). In patients with drug-resistant mesial temporal lobe epilepsy (MTLE), hippocampal sclerosis type 1 (HS1) is the most common histopathological finding. This study aimed to evaluate the ECM profile of HS1 in surgically treated drug-resistant patients with MTLE in correlation to clinical findings. Hippocampal sections were immunohistochemically stained for aggrecan, neurocan, versican, chondroitin-sulfate (CS56), fibronectin, Wisteria floribunda agglutinin (WFA), a nuclear neuronal marker (NeuN), parvalbumin (PV), and glial-fibrillary-acidic-protein (GFAP). In HS1, besides the reduced number of neurons and astrogliosis, we found a significantly changed expression pattern of versican, neurocan, aggrecan, WFA-specific glycosylation, and a reduced number of PNNs. Patients with a lower number of epileptic episodes had a less intense diffuse WFA staining in Cornu Ammonis (CA) fields. Our findings suggest that PNN reduction, changed ECM protein, and glycosylation expression pattern in HS1 might be involved in the pathogenesis and persistence of drug-resistant MTLE by contributing to the increase of CA pyramidal neurons’ excitability. This research corroborates the validity of ECM molecules and their modulators as a potential target for the development of new therapeutic approaches to drug-resistant epilepsy.     

W5O14 Nanowires

We report on the synthesis of quasi‐1D W₅O₁₄ crystals using NiI₂ as a growth promoter. Photoelectron spectroscopy revealed the metallic conductivity of the W₅O₁₄ nanowires, which was also confirmed by direct‐transport measurements on a double‐stranded nanowire. Scanning electron microscopy and transmission electron‐diffraction data are correlated with details of crystal growth revealing the possible mechanism of the formation of this rarely synthesized phase, which was reported as a homogeneous phase only in 1978 by McColm et al., and in the meantime has been declared as a compound that is rare.     

Edge adaptive upsampling of depth map videos for enhanced free-viewpoint video quality

Quality enhancement of free-viewpoint videos is addressed for 3D video systems that use the colour texture video plus depth map representation format. More specifically, a novel and efficient shape adaptive filter is presented for upsampling depth map videos that are of lower resolution than their colour texture counterparts. Either measurement or estimation of depth map videos can take place at lower resolution. At the same time, depth map reconstruction takes place at low resolution if reduced resolution compression techniques are utilised. The proposed design is based on the observation that significant transitions in depth intensity across depth map frames influence the overall quality of generated free-viewpoint videos. Hence, sharpness and accuracy in the free-viewpoint videos rendered using 3D geometry via depth maps, especially across object borders, are targeted. Accordingly, significant enhancement of rendered free-viewpoint video quality is obtained when the proposed method is applied on top of MPEG spatial scalability filters.     

Measurement Accuracy of Oscillation‐Based Test of Analog‐to‐Digital Converters

Oscillation‐based testing of analog‐to‐digital converters represents a viable option for low‐cost built‐in self‐testing in mixed‐signal design. While numerous papers have addressed implementation issues, little attention has been paid to the measurement accuracy. In this letter, we highlight an inherent measurement uncertainty which has to be considered when deriving the parameters from the oscillation frequency.     

Side information refinement using motion estimation in dc domain for transform-based distributed video coding

The key to good decoding performance in distributed video coding systems lies in the efficient prediction of frames using side information. Previously, this process has been performed without considering the progressive nature of the synthesis of the final frame. Observing the fact that incorrectly predicted areas of the current frame can be detected at different levels of final frame synthesis, an algorithm is proposed for refinement of side information synthesis based on an additional stage of motion estimation. The additional stage is performed on correctly decoded DC frames and is used to significantly improve the motion prediction of the final resolution frames, which leads to enhanced performance of the overall system.     

Thick-film resistor quality indicator based on noise index measurements

A quality indicator for thick-film resistors based on noise index and resistance measurements is proposed. As this correlates resistor transport and noise characteristics and has mobility dimensions, we titled it to be noise reduced mobility. The experimental results for thick-film resistors, realized using three different resistor compositions with sheet resistances of 1, 10 and 100 kΩ m/sqr show that layers with sheet resistance of 10 kΩ0.25>m/sqr have minimum value of noise reduced mobility in comparison with layers formed using resistor compositions with sheet resistances of 1 and 100 kΩ m/sqr. The potential and resistance distributions measured along test resistors show that the noise reduced mobility is in correlation with thick-film inhomogeneity.