16 research outputs found

    Improved depth coding for HEVC focusing on depth edge approximation

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    The latest High Efficiency Video Coding (HEVC) standard has greatly improved the coding efficiency compared to its predecessor H.264. An important share of which is the adoption of hierarchical block partitioning structures and an extended number of modes. The structure of existing inter-modes is appropriate mainly to handle the rectangular and square aligned motion patterns. However, they could not be suitable for the block partitioning of depth objects having partial foreground motion with irregular edges and background. In such cases, the HEVC reference test model (HM) normally explores finer level block partitioning that requires more bits and encoding time to compensate large residuals. Since motion detection is the underlying criteria for mode selection, in this work, we use the energy concentration ratio feature of phase correlation to capture different types of motion in depth object. For better motion modeling focusing at depth edges, the proposed technique also uses an extra pattern mode comprising a group of templates with various rectangular and non-rectangular object shapes and edges. As the pattern mode could save bits by encoding only the foreground areas and beat all other inter-modes in a block once selected, the proposed technique could improve the rate-distortion performance. It could also reduce encoding time by skipping further branching using the pattern mode and selecting a subset of modes using innovative pre-processing criteria. Experimentally it could save 29% average encoding time and improve 0.10 dB Bjontegaard Delta peak signal-to-noise ratio compared to the HM

    Constitutive and Induced Expression of Total Phenol and Phenol Oxidases in Wheat Genotypes Ranging in Resistance/Susceptibility to the Root-Lesion Nematode Pratylenchus thornei

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    Plant-derived phenolic compounds contribute to the defense against various pathogens, including root-lesion nematodes (Pratylenchus spp.). However, there are no reports on the role of phenolic compounds in wheat (Triticum aestivum) against Pratylenchus thornei. In this study, wheat genotypes ranging from resistant to very susceptible to P. thornei were used to investigate the level of total phenols and phenol oxidases, polyphenol oxidase (PPO), and peroxidase (POD) expressed in root tissues when grown in the presence and absence of P. thornei over time (2–8 weeks). Higher constitutive levels of total phenols were found in resistant synthetic hexaploid wheats CPI133872 (576 µg gallic acid equivalent (GAE)/g root) and CPI133859 (518 µg GAE/g root) at 8 weeks after sowing, compared with moderately resistant and susceptible genotypes (192 to 390 µg GAE/g root). The activity of PPO was induced in resistant (CPI133872) and moderately resistant (GS50a and its derivate QT8343) genotypes, becoming maximal at 4 weeks after P. thornei inoculation. The activity of POD was induced in CPI133872 at 6 weeks after P. thornei inoculation. Different genetic sources of resistance to P. thornei showed diverse defense mechanisms and differences in timing responses. The combined effects of total phenols and oxidative enzymes could be important for defense against P. thornei in some resistant wheat genotypes

    Identifying individual nutrient deficiencies of grapevine leaves using hyperspectral imaging

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    The efficiency of a vineyard management system is directly related to the effective management of nutritional disorders, which significantly downgrades vine growth, crop yield and wine quality. To detect nutritional disorders, we successfully extracted a wide range of features using hyperspectral (HS) images to identify healthy and individual nutrient deficiencies of grapevine leaves. Features such as mean reflectance, mean first derivative reflectance, variation index, mean spectral ratio, normalised difference vegetation index (NDVI) and standard deviation (SD) were employed at various stages in the ultraviolet (UV), visible (VIS) and near-infrared (N.I.R.) regions for our experiment. Leaves were examined visually in the laboratory and grouped as either healthy (i.e. control) or unhealthy. Then, the features of the leaves were extracted from these two groups. In a second experiment, features of individual nutrient-deficient leaves (e.g., N, K and Mg) were also analysed and compared with those of control leaves. Furthermore, a customised support vector machine (SVM) was used to demonstrate that these features can be utilised with a high degree of effectiveness to identify unhealthy samples and not only to distinguish from control and nutrient deficient but also to identify individual nutrient defects. Therefore, the proposed work corroborated that HS imaging has excellent potential to analyse features based on healthiness and individual nutrient deficiencies of grapevine leaves

    Elucidation of biochemical defence mechanisms in wheat (Triticum aestivum L.) against root-lesion nematode (Pratylenchus thornei)

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    The Abstract is currently unavailable, due to the thesis being under Embargo

    Temperature-dependent study of AcFc-FeIII(acac)3 redox couple for non-aqueous redox flow battery

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    This article describes the temperature dependence electrochemical analysis of acetyl ferrocene (AcFc) and iron(III) acetylacetonate ([Fe(acac)3]) for non-aqueous redox flow batteries. An electrochemical cell consisting of AcFc and ([Fe(acac)3]) as catholyte and anolyte species, respectively, were constructed with a cell voltage of 1.41 V and Coulombic efficiencies >99% for up to 50 total cycles at 25o C (RT) and 0o C. Rotating ring disk electrode (RRDE) experiments suggest that diffusion coefficient decreases as the temperature decreases but overall storing capacity far better than aqueous redox flow battery (ARFBs). The electrochemical kinetic rate constant (k0) of AcFc was found larger than Fe(acac)3 but remains similar at both temperatures. NMR study shows no structural change in changing temperature and after battery experiments

    Joint texture and depth map coding for error-resilient 3-D video transmission

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    This paper addresses the problem of error-resilient source coding for 3-D video transmitted over packet-loss networks. The approach jointly optimizes the texture coding mode and the depth coding mode for each macroblock in the reference views. Firstly, a distortion model is developed to capture the effect of the texture distortion and depth distortion on the synthesized view. Then, joint optimization of texture and depth coding modes is derived within an operational rate-distortion framework using Lagrange multiplier method. In particular, a dual trellis-based algorithm is introduced in order to overcome the macroblock interdependencies of texture and depth map in the optimization procedure. Simulation results demonstrate that consistent gains can be achieved over currently used techniques

    Understanding the Intricacies of Iron Overload Associated with β-Thalassemia: A Comprehensive Review

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    β-thalassemia, a congenital genetic hematological disorder characterized by the decrease or absence of β-globin chains, leads to a decrease in levels of Hemoglobin A. The affected individuals can be categorized into two cohorts based on transfusion dependency: transfusion-dependent thalassemia (TDT) and non-transfusion-dependent thalassemia (NTDT). Remarkably, despite the primary pathology lying in β-globin chain depletion, β-thalassemia also exhibits an intriguing association with iron overload. Iron metabolism, a tightly regulated physiological process, reveals a complex interplay in these patients. Over time, both cohorts of β-thalassemic individuals develop iron overload, albeit through distinct mechanisms. Addressing the diverse complications that arise due to iron overload in β-thalassemic patients, the utilization of iron chelators has gained a lot of significance. With varying efficacies, routes of administration, and modes of action, different iron chelators offer unique benefits to patients. In the Indian context, three commercialized iron chelators have emerged, showcasing a high adherence rate to iron chelator-based treatment regimens among β-thalassemic individuals. In this review, we explore the intriguing connection between β-thalassemia and iron overload, shedding light on the intricate mechanisms at play. We delve into the intricacies of iron metabolism, unveiling the distinct pathways leading to iron accumulation in these patients. Additionally, the therapeutic efficacy of different iron chelators in managing iron overload complications is mentioned briefly, along with the guidelines for their usage in India. Through this comprehensive analysis, we aim to deepen our understanding of β-thalassemia and iron overload, paving the way for optimized treatment strategies. Ultimately, our findings provide valuable insights into improving the care and outcomes of individuals affected by β-thalassemia

    Metabolomic profiling of wheat genotypes resistant and susceptible to root‑lesion nematode Pratylenchus thornei

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    The root-lesion nematode Pratylenchus thornei reduces wheat production in many parts of the world. In this study the metabolic profiles of two wheat genotypes ‘QT16258’ (moderately resistant) and ‘Janz’ (susceptible) were compared at 8 weeks post inoculation with or without P. thornei. We performed untargeted liquid chromatography mass spectrometry analysis (LC–MS) of the wheat root samples. A total of 11,704 MS features were identified, out of which 765 MS features were annotated using in-house chemical standards. Principal components analysis (PCA) and partial least square discriminant analysis (PLS-DA) indicated dissimilarity of the metabolome between P. thornei resistant and susceptible genotypes. Two-way analysis of variance indicated that metabolic differences were mainly constitutive rather than induced by inoculation with P. thornei. Eighty-four annotated metabolites were significantly (p ≤ 0.01) higher in relative concentration in ‘QT16258’ than ‘Janz’ and belonged to the following classes of metabolites: flavonoids, fatty acids, glycerolipids, alkaloids, tannins, nucleotides, steroid glycosides and terpenoids. Eighty-five annotated metabolites were significantly (p ≤ 0.01) higher in relative concentration in ‘Janz’ than ‘QT16258’ and belonged to the following classes of metabolites: amino acids, sugars, flavonoids and alkaloids. Several metabolites at higher concentration in ‘QT16258’, including quercetin-3,4’-Odi-beta-glucoside (flavonoid), linoleic acid (fatty acid), lysophosphatidylethanolamine (glycerolipid), hirsutine alkaloid),1-methylsulfinylbutenyl-isothiocyanate (glucosinolate), could potentially strengthen the root cell walls to inhibit nematode penetration and/or reduce nematode motility. Some metabolites at higher concentrations in susceptible ‘Janz’, including phenolics, coniferyl alcohol and indole acetic acid conjugates, could be nematode attractants as well as part of a hypersensitive browning reaction to nematode invasion
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