Joint depth-motion dense estimation for multiview video coding

The multiview video coding (MVC) extension of H.264/MPEG-4 AVC [1] is one of the most promising visual encoders for three-dimensional television and free viewpoint video applications. In this paper, we propose a joint dense motion/disparity estimation algorithm, designed to replace the classical temporal/inter-view unit within MVC, which uses a block-based motion/disparity estimation. The motion vector fields and the disparity vector fields are therefore simultaneously derived using the stereo-motion consistency constraint in a set theoretic convex optimization framework. The obtained displacement vector fields are then jointly segmented by minimizing a rate-distortion cost function, in line with the multiple reference frame strategy used in H.264/MPEG-4 AVC. Experimental results demonstrate the benefits of the proposed method compared to the separated dense estimation scheme or the block-based estimation technique.     

In silico classification of HERG channel blockers: a knowledge-based strategy

The blockage of the hERG potassium channel by a wide number of diverse compounds has become a major pharmacological safety concern as it can lead to sudden cardiac death. In silico models can be potent tools to screen out potential hERG blockers as early as possible during the drug-discovery process. In this study, predictive models developed using the recursive partitioning method and created using diverse datasets from 203 molecules tested on the hERG channel are described. The first model was built with hERG compounds grouped into two classes, with a separation limit set at an IC50 value of 1 microm, and reaches an overall accuracy of 81%. The misclassification of molecules having a range of activity between 1 and 10 microM led to the generation of a tri-class model able to correctly classify high, moderate, and weak hERG blockers with an overall accuracy of 90%. Another model, constructed with the high and weak hERG-blocker categories, successfully increases the accuracy to 96%. The results reported herein indicate that a combination of precise, knowledge management resources and powerful modeling tools are invaluable to assessing potential cardiotoxic side effects related to hERG blockage.     

Class I/Class IIa bacteriocin cross-resistance phenomenon in Listeria monocytogenes

Variants resistant to nisin A (vA), nisin Z (vZ), pediocin PA-1 (vP), divergicin M35 (vD) and to bacteriocin-like compounds produced by Bifidobacterium thermophilum subsp. infantis RBL67 (vB) were developed from Listeria monocytogenes LSD530. Lactic acid production, specific growth rate, potassium ion efflux, susceptibility to 13 antibiotics, cell-envelope fatty acid composition and bacteriocin cross-resistance were evaluated. Lactic acid production decreased to 75% or less of that by strain LSD530 for vP, vD and vB and to 20% or less for vA and vZ. Specific growth rates also decreased for all five variants. Acquired resistance to nisin A or Z increased resistance to pediocin and divergicin while vD showed increased resistance to nisin Z but decreased resistance to nisin A and vP exhibited increased resistance to nisin Z, pediocin and divergicin but decreased resistance to nisin A. Acquired bacteriocin resistance generally decreased antibiotic sensitivity, particularly to ampicillin, chloramphenicol, erythromycin and tetracycline. Palmitic acid (C(16:0)) in the cell wall fraction of all variants was significantly higher than in strain LSD530, accounting for 18%, 43%, 32%, 26%, 53% and 44% of the total fatty acids for LSD530, vP, vD, vB, vA, and vZ, respectively. The relationship between the acquisition of bacteriocin resistance, cross-resistance and pathogenicity of Listeria monocytogenes should be studied.     

Effect of feeding whey peptide fractions on the immune response in healthy and Escherichia coli infected mice

The antimicrobial and immunomodulatory activities of whey proteins and peptides make them promising candidates for protection against pathogens. To test this hypothesis, a whey protein isolate and three peptide fractions obtained from its trypsin/chymotrypsin digestion were given orally to mice for 7 days. Half the mice were then infected with Escherichia coli O157:H7 and serum cytokines and total immunoglobulin A (IgA) were measured over the next 7 days. All whey products strongly stimulated total IgA production in non-infected mice, suggesting a potential adjuvant role. The peptide fractions produced contrasting immunomodulatory effects: the neutral fraction (4.5 < pH < 7) stimulated serum interferon-gamma (IFN-γ), whereas the acidic fraction (pH < 4.5) inhibited it. In the infected model, only the basic fraction (pH > 7) induced a sustained serum IgA secretion, which coincided with increased transforming growth factor-beta 1 (TGF-β1) levels. These results indicate that some whey peptides modulate immune parameters in healthy mice, whereas the basic peptide fraction increased immune vigilance during the infection.     

Effectiveness of Alkali and Sodium Bicarbonate Treatments on Sugar Palm Fiber: Mechanical,Thermal, and Chemical Investigations

ABSTRACT

Sugar palm fiber (SPF) as one of the attractive natural fibers to reinforce matrix is gaining attention. This is largely due to its similar properties when compared with other established natural fibers. The aim of this study is to investigate the effectiveness of sodium bicarbonate as a treatment chemical for SPF in comparison with established alkaline treatment. Both treated and untreated fibers were characterized and it was found that the treated fiber shows an increase in crystallinity, thermal stability, and surface’s roughness when compared with the untreated. Among the two different treatments, SPF treated with alkali has an initial decomposition temperature of 255.47°C, while sodium bicarbonate treated and untreated fibers have 250.19°C and 246.76°C, respectively. In both cases, the thermal stability of the fiber was improved. Also, as revealed by the X-ray diffraction (XRD) analysis, the crystallinity index of SPF treated with alkali and sodium bicarbonate increased by 18.43% and 13.60%, respectively, when compared with untreated fiber. In conclusion, the investigation proved that treatment with the sodium bicarbonate has a significant effect on the physicochemical properties of SPF and the chemical could be an alternative chemical for treating other cellulose fibers.     

A Risk Poker Based Testing Model for Scrum

In agile software development, project estimation often depends on group discussion and expert opinions. Literature claims that group discussion in risk analysis helps to identify some of the crucial issues that might affect development, testing, and implementation. However, risk prioritization often relies on individual expert judgment. Therefore, Risk Poker, a lightweight risk-based testing methodology in which risk analysis is performed through group discussion that outperforms the individual analyst’s estimation is introduced in agile methods. Keeping in view aforementioned benefits Risk Poker can offer, unfortunately, no study has been conducted to empirically prove its ability to improve the testing process to date. Therefore, this research is aimed at closing this research gap by (i) deploying Risk Poker technique as a risk-based strategy in the agile development lifecycle, and (ii) empirically evaluating improvement of the proposed test process. For this purpose, Risk Poker technique is coupled with test coverage for an innovated testing process in an agile project following Scrum in order to provide adequate test coverage for testing activity. A case study was conducted with 6 teams of undergraduate students to estimate test coverage using Risk Poker for an e-commerce system. Three teams estimated their user stories using Risk Poker, while the rest estimated individually and used an average to obtain the statistical combination. The results showed that the proposed usage of Risk Poker for risk analysis and estimate test coverage outperformed the averaged statistical estimation of risk analysis for user stories.     

Calcul de l'effet d'un etat d'interface sur le travail de sorte d'un semiconducteur recouvert d'une couche mince

We carried out a theoretical investigation of the work function of a semiconductor covered with a thin film. We assumed that the layer was also a semiconductor and that there was an interface state. The structure is regarded as a heterojunction in which the space charge may extend over the whole thickness of the layer. Results are given for an example: the Ge/GaAs heterojunction.     

Discogenic Low Back Pain: Anatomy,Pathophysiology and Treatments of Intervertebral Disc Degeneration

Intervertebral disc (IVD) degeneration is a major contributing factor for discogenic low back pain (LBP), causing a significant global disability. The IVD consists of an inner core proteoglycan-rich nucleus pulposus (NP) and outer lamellae collagen-rich annulus fibrosus (AF) and is confined by a cartilage end plate (CEP), providing structural support and shock absorption against mechanical loads. Changes to degenerative cascades in the IVD cause dysfunction and instability in the lumbar spine. Various treatments include pharmacological, rehabilitation or surgical interventions that aim to relieve pain; however, these modalities do not halt the pathologic events of disc degeneration or promote tissue regeneration. Loss of stem and progenitor markers, imbalance of the extracellular matrix (ECM), increase of inflammation, sensory hyperinnervation and vascularization, and associated signaling pathways have been identified as the onset and progression of disc degeneration. To better understand the pain originating from IVD, our review focuses on the anatomy of IVD and the pathophysiology of disc degeneration that contribute to the development of discogenic pain. We highlight the key mechanisms and associated signaling pathways underlying disc degeneration causing discogenic back pain, current clinical treatments, clinical perspective and directions of future therapies. Our review comprehensively provides a better understanding of healthy IVD and degenerative events of the IVD associated with discogenic pain, which helps to model painful disc degeneration as a therapeutic platform and to identify signaling pathways as therapeutic targets for the future treatment of discogenic pain.     

Polyimide molecular composites containing a stiff‐chain polymer derived from 1,5‐diaminonaphathalene and pyromellitic dianhydride

Polyimide molecular composite (MC) films were prepared by embedding a stiff‐chain polyimide (PI_S) in the ductile matrix of a flexible‐chain polyimide (PI_F) by blending their respective poly(amic acid) precursor solutions, followed by casting, drying, and thermal imidization upto 300°C. The PI_S was prepared from pyromellitic dianhydride (PMDA) and 1,5‐diaminonaphathalene (DAN), whereas the PI_F was prepared from the same dianhydride and 4,4′‐oxydianiline (ODA). Transparent, tough, and creasable MC films were obtained with 2.5–40 wt% of PI_S content. The disruption of crystalline order of PI_S in the MC films evidenced its fine dispersion in the matrix. Visco‐elastic measurements showed a single and enhanced value of the glass transition temperature for MC films indicating miscibility of this polyimide pair. Furthermore, the variation of charge transfer (CT) fluorescence intensity with the PI_S content in the blends verified complete miscibility upto 30 wt% of PI_S loading. These MCs showed a notable enhancement in the mechanical properties. Among all, the blend containing 30 wt% of stiff‐chain molecules gave the best combination of properties when compared with the matrix polyimide: a 50% higher value of tensile modulus, a 17°C rise in the glass transition temperature, and better thermal stability. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers