Computational performance of a parallelized three-dimensional high-order spectral element toolbox

In this paper, a comprehensive performance review of an MPI-based high-order three-dimensional spectral element method C++ toolbox is presented. The focus is put on the performance evaluation of several aspects with a particular emphasis on the parallel efficiency. The performance evaluation is analyzed with the help of a time prediction model based on a parameterization of the application and the hardware resources. Two tailor-made benchmark cases in computational fluid dynamics (CFD) are introduced and used to carry out this review, stressing the particular interest for clusters with up to thousands of cores. Some problems in the parallel implementation have been detected and corrected. The theoretical complexities with respect to the number of elements, to the polynomial degree, and to communication needs are correctly reproduced. It is concluded that this type of code has a nearly perfect speedup on machines with thousands of cores, and is ready to make the step to next-generation petaFLOP machines.     

Collective knowledge systems: Where the Social Web meets the Semantic Web

What can happen if we combine the best ideas from the Social Web and Semantic Web? The Social Web is an ecosystem of participation, where value is created by the aggregation of many individual user contributions. The Semantic Web is an ecosystem of data, where value is created by the integration of structured data from many sources. What applications can best synthesize the strengths of these two approaches, to create a new level of value that is both rich with human participation and powered by well-structured information? This paper proposes a class of applications called collective knowledge systems, which unlock the “collective intelligence” of the Social Web with knowledge representation and reasoning techniques of the Semantic Web.     

Defect identification and sizing by the ultrasonic satellite-pulse technique

Shape and size are the most important defect characteristics that need to be determined for the reliable prediction of the remaining service lifetime of a defective structure or part. The analytical and supporting experimental results presented in this paper concern a general, pattern recognition-based, ultrasonic defect identification and sizing method. The satellite-pulse technique (SPT) is based on the interpretation, in terms of defect types (shapes) and dimensions, of the separation in time of arrival between the readily detected specularly reflected pulse and its generally ignored tip-diffracted or tangentially scattered satellite contained in the received waveform. Calibration procedures were also developed that enable the ultrasonic examiner to read the time scale of the oscilloscope for equivalent crack depth or void diameter as appropriate.     

Device-based decision-making for adaptation of three-dimensional content

The goal of this research was the creation of an adaptation mechanism for the delivery of three-dimensional content. The adaptation of content, for various network and terminal capabilities – as well as for different user preferences, is a key feature that needs to be investigated. Current state-of-the art research of the adaptation shows promising results for specific tasks and limited types of content, but is still not well-suited for massive heterogeneous environments. In this research, we present a method for transmitting adapted three-dimensional content to multiple target devices. This paper presents some theoretical and practical methods for adapting three-dimensional content, which includes shapes and animation. We also discuss practical details of the integration of our methods into MPEG-21 and MPEG-4 architectures.     

Finite element evaluation of free-edge singular stress fields in anisotropic materials

A finite element formulation based on the work of Yamada and Okumura¹⁴ is presented to determine the order of singularity and angular variation of the stress and displacement fields surrounding a singular point on a free edge of anisotropic materials. Emphasis is placed on the computational aspects of this method when applied to configurations including fully bonded multi-material junctions intersecting a free edge as well as materials containing cracks intersecting a free edge. The study shows that the singularity of the three-dimensional stress field may be accurately determined with a relatively small number of elements only when a proper level of numerical integration is used. The method is applied to isotropic and orthotropic materials with a crack intersecting a free edge and an anisotropic three-material junction intersecting a free edge. The efficiency and accuracy of the method indicates it could be used to develop a numerical solution for the singular field that could in turn be used to create free-edge enriched finite elements.     

Revisiting the Roles of Filaggrin in Atopic Dermatitis

The discovery in 2006 that loss-of-function mutations in the filaggrin gene (FLG) cause ichthyosis vulgaris and can predispose to atopic dermatitis (AD) galvanized the dermatology research community and shed new light on a skin protein that was first identified in 1981. However, although outstanding work has uncovered several key functions of filaggrin in epidermal homeostasis, a comprehensive understanding of how filaggrin deficiency contributes to AD is still incomplete, including details of the upstream factors that lead to the reduced amounts of filaggrin, regardless of genotype. In this review, we re-evaluate data focusing on the roles of filaggrin in the epidermis, as well as in AD. Filaggrin is important for alignment of keratin intermediate filaments, control of keratinocyte shape, and maintenance of epidermal texture via production of water-retaining molecules. Moreover, filaggrin deficiency leads to cellular abnormalities in keratinocytes and induces subtle epidermal barrier impairment that is sufficient enough to facilitate the ingress of certain exogenous molecules into the epidermis. However, although FLG null mutations regulate skin moisture in non-lesional AD skin, filaggrin deficiency per se does not lead to the neutralization of skin surface pH or to excessive transepidermal water loss in atopic skin. Separating facts from chaff regarding the functions of filaggrin in the epidermis is necessary for the design efficacious therapies to treat dry and atopic skin.     

Struktur und Eigenschaften gepfropfter Kartoffelstärke. III. Mikrostruktur und Bindungsverhältnisse in der Pfropf-co-polymer-Phase

Structure and Properties of Grafted Potatoe Starch. III. Microstructure and Interchain Bonds in the Graft-Copolymer-Phase Graft copolymers of polyacrylic acid and polymethacrylic acid, grafted according to the Scott-xanthation process were investigated. By combining different optical methods information could be obtained about interchain bonds in the copolymer phase. From frequency, shape and intensity of different infra-red absorption bands it could be concluded that there are hydrogen bridges from the carboxylic groups of the side chain polymer to the hydroxyl groups of the backbone-polysaccharid. These bonds lead to a crystalline copolymer phase which is different from starch and have an influence on the configuration of the polysaccharid chains in solution.     

Blood Clots versus PRF: Activating TGF-β Signaling and Inhibiting Inflammation In Vitro

The preparation of platelet-rich fibrin (PRF) requires blood centrifugation to separate the yellow plasma from the red erythrocyte fraction. PRF membranes prepared from coagulated yellow plasma are then transferred to the defect sites to support tissue regeneration. During natural wound healing, however, it is the unfractionated blood clot (UBC) that fills the defect site. It is unclear whether centrifugation is necessary to prepare a blood-derived matrix that supports tissue regeneration. The aim of the present study was to compare lysates prepared from PRF and UBC based on bioassays and degradation of the respective membranes. We report here that lysates prepared from PRF and UBC membranes similarly activate TGF-β signaling, as indicated by the expression of interleukin 11 (IL-11), NADPH oxidase 4 (NOX-4) and proteoglycan 4 (PRG4) in gingival fibroblasts. Consistently, PRF and UBC lysates stimulated the phosphorylation and nuclear translocation of Smad3 in gingival fibroblasts. We further observed that PRF and UBC lysates have comparable anti-inflammatory activity, as shown by the reduction in lipopolysaccharide (LPS)-induced IL-6, inducible nitric oxidase synthase (iNOS) and cyclooxygenase 2 (COX-2) expression in RAW264.7 cells. Moreover, inflammation induced by Poly (1:C) HMW and FSL-1, which are agonists of Toll-like receptor (TLR) 3 and 2/6, respectively, was reduced by both PRF and UBC. PRF and UBC lysates reduced the nuclear translocation of p65 in LPS-induced RAW264.7 cells. In contrast to the similar activity observed in the bioassays, UBC membranes lack the structural integrity of PRF membranes, as indicated by the rapid and spontaneous disintegration of UBC membranes. We show here that the lysates prepared from PRF and UBC possess robust TGF-β and anti-inflammatory activity. However, visual inspection of the PRF and UBC membranes confirmed the negative impact of erythrocytes on the structural integrity of membranes prepared from whole blood. The data from the present study suggest that although both UBC and PRF have potent TGF-β and anti-inflammatory activity, UBC does not have the strength properties required to be used clinically to prepare applicable membranes. Thus, centrifugation is necessary to generate durable and clinically applicable blood-derived membranes.