Spatial pooling strategies for perceptual image quality assessment

Many recently proposed perceptual image quality assessment algorithms are implemented in two stages. In the first stage, image quality is evaluated within local regions. This results in a quality/distortion map over the image space. In the second stage, a spatial pooling algorithm is employed that combines the quality/distortion map into a single quality score. While great effort has been devoted to developing algorithms for the first stage, little has been done to find the best strategies for the second stage (and simple spatial average is often used). In this work, we investigate three spatial pooling methods for the second stage: Minkowski pooling, local quality/distortion-weighted pooling, and information content-weighted pooling. Extensive experiments with the LIVE database show that all three methods may improve the prediction performance of perceptual image quality measures, but the third method demonstrates the best potential to be a general and robust method that leads to consistent improvement over a wide range of image distortion types. Index Terms: image quality assessment, visual perception, structural similarity, error pooling, information conten

Perceptual image coding based on a maximum of minimal structural similarity criterion

Perceptual image coding algorithms typically impose perceptual modeling in a preprocessing stage. A perceptual normalization model is often used to transform the original image signal into a perceptually uniform space, in which all the transform coefficients have equal perceptual importance. Standard coding schemes are then applied uniformly to all coefficients. Here we use a different approach, in which we iteratively reallocates the available bits over the image space based on a maximum of minimal structural similarity criterion. We demonstrate the proposed method by incorporating it with the bitplane coding scheme in the set partitioning in hierarchical trees algorithm. Index Terms — perceptual image coding, image quality assessment, structural similarity (SSIM), bitplane coding, set partitioning in hierarchical trees (SPIHT) (a) (b

A Survey of Deployment Solutions and Optimization Strategies for Hybrid SDN Networks

© 1998-2012 IEEE. A hybrid software defined networks (SDN) network contains both traditional and SDN network, which combines the robustness of traditional protocols with the flexibility of SDN while avoiding their limitations and incompatibility. However, a hybrid SDN network comes with its own set of challenges, including error-prone deployment processes, risks of inconsistency, and complex incremental deployment strategies. In this paper, we present a survey of the deployment solutions and optimization strategies for hybrid SDN networks. We systematically review solutions to control plane and data plane deployments, and describe typical use cases of hybrid SDN networks. We discuss and compare various optimization strategies from perspectives of traffic engineering, resource saving, network control capacity, and network security. This paper aims to provide insights to researchers into the future development of hybrid SDN networks and inspire more efforts in this area

MiR-146a promotes remyelination in a cuprizone model of demyelinating injury

The death of mature oligodendrocytes (OLs) which are the sole myelinating cells of the central nervous system (CNS), leads to demyelination and functional deficits. Currently, there is lack of effective remyelination therapies for patients with demyelinating diseases. MicroRNAs (miRNAs) mediate OL function. We hypothesized that miR-146a, by inactivating interleukin-1 receptor-associated kinase 1 (IRAK1), promotes differentiation of oligodendrocyte progenitor cells (OPCs) and thereby enhances remyelination. To test this hypothesis, a demyelination model induced by a cuprizone (CPZ) diet was employed, in which C57BL/6J mice were fed with a CPZ diet for 5weeks. After termination of CPZ diet, the mice were randomly treated with continuous infusion of miR-146a mimics or mimic controls into the corpus callosum for 7days. Compared to the mimic control, infusion of miR-146a mimics facilitated remyelination assessed by increased myelin basic proteins in the corpus callosum, which was associated with augmentation of newly generated mature OLs. Infusion of miR-146a mimics also substantially elevated miR-146a levels in the corpus callosum and fluorescently tagged miR-146a mimics were mainly detected in OPCs. Western blot and double immmunofluorescent staining analysis showed that the miR-146a treatment considerably reduced IRAK1 protein levels and the number of IRAK1-positive cells, respectively. Collectively, these data indicate that exogenous miR-146a enhances remyelination, possibly by promoting OPCs to differentiate into myelinated OLs via targeting IRAK1

Effects of dietary supplementation with leonurine hydrochloride on growth performance, immune response, antioxidant capacity and blood parameters in male broiler chicks

The aim of the present study was to explore the effects of different dietary levels (0, 15, 30, 60, 120 mg/kg) of leonurine hydrochloride (LHy) supplementation on growth performance, immune response, antioxidant capacity, hematological parameters and serum lipid profiles in broiler chicks. A total of 600 1-day-old Ross × Ross male broilers were randomly allocated to five treatment groups consisting of eight pens of fifteen birds. The feeding programme included a starter diet until day 21 and a finisher diet from day 22 to day 42. The results indicate that LHy did not alter the growth performance of broilers (P > 0.05). Supplementation of the basal diet with LHy increased (linear, P < 0.05) relative spleen weights at d 21 and 42. In both 21- and 42-day-old chicks, dietary LHy supplementation linearly increased (P < 0.05) the serum immunoglobulin A (IgA) and M (IgM) concentrations, catalase (CAT), total superoxide dismutase (T-SOD), total antioxidant capacity (T-AOC) activities, low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) levels, while linearly (P < 0.05) decreased serum malondialdehyde (MDA) activity, red blood cell (RBC) count, hemoglobin, triglyceride (TC) levels and total cholesterol (CHOL) content. In addition dietary LHy supplementation linearly (P < 0.05) increased the GSH activity in 42-day-old broilers. Taken together, dietary LHy supplementation was able to promote immune function and antioxidant capacity, and decrease blood lipid levels in broilers

Biodegradable metals for bone defect repair: A systematic review and meta-analysis based on animal studies

Biodegradable metals are promising candidates for bone defect repair. With an evidence-based approach, this study investigated and analyzed the performance and degradation properties of biodegradable metals in animal models for bone defect repair to explore their potential clinical translation. Animal studies on bone defect repair with biodegradable metals in comparison with other traditional biomaterials were reviewed. Data was carefully collected after identification of population, intervention, comparison, outcome, and study design (PICOS), and following the inclusion criteria of biodegradable metals in animal studies. 30 publications on pure Mg, Mg alloys, pure Zn and Zn alloys were finally included after extraction from a collected database of 2543 publications. A qualitative systematic review and a quantitative meta-analysis were performed. Given the heterogeneity in animal model, anatomical site and critical size defect (CSD), biodegradable metals exhibited mixed effects on bone defect repair and degradation in animal studies in comparison with traditional non-degradable metals, biodegradable polymers, bioceramics, and autogenous bone grafts. The results indicated that there were limitations in the experimental design of the included studies, and quality of the evidence presented by the studies was very low. To enhance clinical translation of biodegradable metals, evidence-based research with data validity is needed. Future studies should adopt standardized experimental protocols in investigating the effects of biodegradable metals on bone defect repair with animal models