A reduced reference video quality assessment of H.264 and mpeg2 codec based on sharpness metric

In this paper, we propose a new perceptually significant video quality metric for the H.264/Motion Picture Expert Group (MPEG)‐4 Advanced Video Coding (AVC) and MPEG2 standard. Our method operates in the spatial domain by using the Sobel filter. The proposed approach does not require a high computational complexity and can be suitable for real‐time evaluation. We evaluate the performance of the proposed method by using three Common Intermediate Format sequences at different compression rates. The comparison of the obtained results is made with some video quality models using “LIVE”, “IVP” and “IRCCyN/IVC 1080i” databases. The performance metrics, i.e. Pearson and Spearman correlation coefficients, indicate that the proposed method gives a good performance in H264 and MPEG2 codec distortions with the three databases comparing with other models.     

Computational modelling of static indentation-induced damage in glass

The present paper is focused on the numerical simulation of a glass plate subjected to static indentation by a spherical indenter. For this purpose, a combined approach of continuum damage mechanics (CDM) and fracture mechanics is performed. Results provided by an axisymmetric finite element model were compared with analytical solutions. A CDM based constitutive model with an anisotropic damage tensor was selected and implemented into a finite element code to study the damage of glass. The numerical results were analysed through the framework of the stress and damage distribution. Various regions with critical damage values were therefore predicted in good agreement with the experimental observations in the literature. In these regions, the directions of crack propagation, including both cracks initiating on the surface as well as in the bulk, were predicted using the strain energy density factor. Predicted directions were found in good agreement with those experimentally obtained in the literature results.     

Molecular dynamics study on vanadium pentoxide

We have studied bulk structure and three low-index surfaces of V₂O₅ using molecular dynamics (MD) simulation. The calculated infra-red (IR) absorption bands of V₂O₅ bulk structure are consistent with the experimental result. The (0 0 1) surface was calculated to be the most stable, small energy difference between the (0 0 1) surface and bulk corresponds their similarity. Atoms with small coordination relax much more than bulk like atoms, they undergo vertical as well as lateral relaxations in order to compensate the missing bonds at the top layer. The driving force which determines the direction of relaxation seems to be the improvement of local environments of the top layer atoms. The vanadyl oxygens exposed to the (0 0 1) and (0 1 0) as well as (1 0 0) surfaces seem to act as active sites in the oxidation process of hydrocarbons.     

Validation of finite element models of liver tissue using micro-CT

In this work, we aim at validating some soft tissue deformation models using high-resolution micro-computed tomography (Micro-CT) images. The imaging technique plays a key role in detecting the tissue deformation details in the contact region between the tissue and the surgical tool (probe) for small force loads and provides good capabilities of creating accurate 3-D models of soft tissues. Surgical simulations rely on accurate representation of the mechanical response of soft tissues subjected to surgical manipulations. Several finite-element models have been suggested to characterize soft tissues. However, validating these models for specific tissues still remain a challenge. In this study, ex vivo lamb liver tissue is chosen to validate the linear elastic model (LEM), the linear viscoelastic model (LVEM), and the neo-Hooke hyperelastic model (NHM). We find that the LEM is more applicable to lamb liver than the LVEM for smaller force loads (< 20 g) and that the NHM is closer to reality than the LVEM for the range of force loads from 5 to 40 g.     

Hematological toxicity associated with tissue extract from poisonous fish Lagocephalus lagocephalus--influence on erythrocyte function in Wistar rats

The puffer fish Lagocephalus lagocephalus represents serious public health problems in the world. The relative toxicity of each organ (liver and flesh) was determined by the relation dose-death time "mouse bioassay." The average liver toxicity of the puffer fish was the highest when compared with flesh giving 14.32 and 10.88 MU/g, respectively. A mouse unit is the amount of toxin (extract of fish organ) that kills a 20 g male mouse in 30 min after intraperitoneal injection. One mouse unit is equivalent to 0.22 microg of TTX. For the rat bioassay tests, Wistar rats were daily i.p. injected, for 10 d, with extracts of liver (LT) or flesh (FT) (muscles + skin) of L. lagocephalus. Control rats received injection of NaCl (0.9%). During the experiment, a significant reduction in red blood cell number (RBC), hemoglobin (HGB) concentration, and hematocrit (HCT) was observed essentially after 10 d of treatment in the FT and LT-exposed groups. Consequently, treatment led to severe anemia and hemolytic action as indicated by a significant reduction in the total number of erythrocytes. In fact, our study revealed a significant increase in erythrocyte lipid peroxidation (LPO) in FT and LT groups compared with controls after experimental exposure. The flesh and liver tissue extracts also altered antioxidative enzymes activities: catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px). Histopathological alterations in the spleen occurred exclusively at the end of treatment. We marked also an increase in reticulo-endothelial cells, which led to remove damaged erythrocytes.     

Mid infrared attenuated total reflection spectroscopy as a rapid tool to assess the quality of Sicilo-Sarde ewe’s milk during the lactation period after replacing soybean meal with scotch bean in the feed ration

This study investigates the potential of attenuated total reflection spectroscopy in the mid infrared (MIR) for monitoring changes in the quality of ewe’s milk as a function of lactation period and feeding systems. Twelve 5-year-old lactating Sicilo-Sarde ewes (third lambing) were kept in environmentally controlled sheepfolds and were divided into two homogenous weight matched groups (n = 6). Ewes were fed ad libitum with two iso-energetic diets (20% barley, 3% vitamin and mineral premix, and 77% soybean meal or scotch bean). Physico–chemical analyses and MIR (3000–900 cm⁻¹) were performed on milk samples after 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 weeks of lactation period. The inclusion of scotch bean in the diet resulted in a significant decrease (P ? 0.05) of fat content (7.85 g 100 g⁻¹ vs. 6.75 g 100 g⁻¹) and a significant increase (P ? 0.05) of lactose level (3.49 g 100 g⁻¹ vs. 3.61 g 100 g⁻¹). The principal component analysis (PCA) applied to the 1700–1500 cm⁻¹ spectral region showed only some discrimination between milk samples according to diet compositions. The best results were obtained in the 3000–2800 cm⁻¹ and 1500–900 cm⁻¹ spectral regions since a good discrimination between milk from ewes fed soybean meal from those fed scotch bean meal was observed. It can be concluded that these spectral regions could be considered as fingerprint, regions allowing a good identification of milk according to diet composition. However, the MIR failed to discriminate milk samples according to the lactation period for the two feeding systems.     

Precise segmentation of 3-D magnetic resonance angiography

Accurate automatic extraction of a 3-D cerebrovascular system from images obtained by time-of-flight (TOF) or phase contrast (PC) magnetic resonance angiography (MRA) is a challenging segmentation problem due to the small size objects of interest (blood vessels) in each 2-D MRA slice and complex surrounding anatomical structures (e.g., fat, bones, or gray and white brain matter). We show that due to the multimodal nature of MRA data, blood vessels can be accurately separated from the background in each slice using a voxel-wise classification based on precisely identified probability models of voxel intensities. To identify the models, an empirical marginal probability distribution of intensities is closely approximated with a linear combination of discrete Gaussians (LCDG) with alternate signs, using our previous EM-based techniques for precise linear combination of Gaussian-approximation adapted to deal with the LCDGs. The high accuracy of the proposed approach is experimentally validated on 85 real MRA datasets (50 TOF and 35 PC) as well as on synthetic MRA data for special 3-D geometrical phantoms of known shapes.     

Structure Evolution and Thermal Decomposition of Supramolecular and Lamellar Hybrid Sulfates Templated by 4-Aminopyridinium

Journal of Inorganic and Organometallic Polymers and Materials - The aromatic diamine 4-aminopyridine was used for the synthesis of a series of supramolecular metal–organic sulfate salts. The...