Local and global error estimations in linear structural dynamics

The study discusses the concept of error estimation in linear elastodynamics. Two different types of error estimators are presented. First ‘classical’ methods based on post-processing techniques are discussed starting from a semidiscrete formulation. The temporal error due to the finite difference discretization is measured independently of the spatial error of the finite element discretization. The temporal error estimators are applied within one time step and the spatial error estimators at a time point. The error is measured in the global energy norm. The temporal evolution of the error cannot be reflected. Furthermore the estimators can only evaluate the mean error of the whole spatial domain. As the second scheme local error estimators are presented. These estimators are designed to evaluate the error of local variables in a certain region by applying duality techniques. Local estimators are known from linear elastostatics and have later on been extended to nonlinear problems. The corresponding dual problem represents the influence of the local variable on the initial problem and may be related to the reciprocal theorem of Betti–Maxwell. In the present study this concept is transferred to linear structural dynamics. Because the dual problem is established over the total space–time domain, the spatial and temporal error of all time steps can be accumulated within one procedure. In this study the space–time finite element method is introduced as a single field formulation.     

The critical resolved shear stress of a superalloy as a combination of those of its γ matrix and γ′ precipitates

The critical resolved shear stress (CRSS), τ ₀, of peak-aged single crystals of the γ′-hardened commercial nickel-base superalloy NIMONIC 105 has been measured as a function of temperature T and orientation [hkl] of the compression axis. The same measurements have been carried out for the two constituent phases of NIMONIC 105: for the single-phase γ matrix and for the single-phase L1₂-long-range ordered γ′ phase. The value of T ranged from 283 to 1150 K, and the following orientations were studied: [001], [011], , and . The specimens were compression tested. The τ ₀ values of NIMONIC 105 and of the γ′ phase are anisotropic; the anisotropy of NIMONIC 105 is similar to that of the γ′ phase, but less pronounced. The τ ₀ of the γ phase is isotropic. The τ ₀ values of the γ and of the γ′ phase vary with T, whereas the τ ₀ of NIMONIC 105 is nearly independent of T for 400 K≤T≤1000 K. A model is presented that relates the function τ ₀ ([h, k, l], T) of NIMONIC 105 to the analogous functions of its constituent γ and γ′ phase.     

Biomarker-Oriented Therapy in Bladder and Renal Cancer

Treatment of patients with urothelial carcinoma (UC) of the bladder or renal cancer has changed significantly during recent years and efforts towards biomarker-directed therapy are being investigated. Immune checkpoint inhibition (ICI) or fibroblast growth factor receptor (FGFR) directed therapy are being evaluated for non-muscle invasive bladder cancer (NMIBC) patients, as well as muscle-invasive bladder cancer (MIBC) patients. Meanwhile, efforts to predict tumor response to neoadjuvant chemotherapy (NAC) are still ongoing, and genomic biomarkers are being evaluated in prospective clinical trials. Currently, patients with metastatic UC (mUC) are usually treated with second-line ICI, while cisplatin-ineligible patients with programmed death-ligand 1 (PD-L1) positive tumors can benefit from first-line ICI. Platinum-relapsed UC patients harboring FGFR2/3 mutations can be treated with erdafitinib, while enfortumab vedotin has emerged as a novel third-line treatment option for mUC. In metastatic (clear cell) renal cell carcinoma (RCC), ICI was first introduced as second-line treatment after vascular endothelial growth factor receptor—tyrosine kinase inhibition (VEGFR-TKI). Currently, ICIs have also been introduced as first-line treatment in metastatic RCC. Although there is no evidence up to now for beneficial adjuvant treatment after surgery with VEGFR-TKIs in high-risk non-metastatic RCC, several trials are underway investigating the potential beneficial effect of ICIs in this setting.     

Anaerobic treatment of acidified and non‐acidified substrata in UASB reactors

The selection of a suitable sludge which will be the inoculum of the reactor is the first step in the start‐up procedure of an anaerobic reactor. The sludge selected (inoculum) for this study was obtained from a UASB (Up‐flow Anaerobic Sludge Bed) reactor used for the treatment of alcohol industry wastewaters. The industrial sludge was used in this work as the inoculum of two laboratory‐scale UASB anaerobic reactors, which were fed with different substrata. The feed for the first reactor was acidified substratum (volatile fatty acid) and the second reactor was fed with non‐acidified substratum (glucose). The purpose of this work was to study the effect of both substrata in regular operation and to analyse the flotation problem which arises when the reactor is fed with a non‐acidified substratum. Finally, the characteristics of the adapted sludge were studied and they were compared with the initial inolucum (sludge). The following observations were noted in relation to the evolution of the sludge during operation: density, TSS content and C, H and N contents remained similar, but the particle size and VSS/TSS increased. The settling volume index decreased and methanogenic and acidogenic activities increased during operation in both reactors. The reactor fed with volatile fatty acids was able to recover from unstable periods faster than the reactor fed with a non‐acidified substratum. The use of an acidified substratum avoided flotation, stabilised the system and reduced the solid content in the effluent. Moreover, it worked properly with partially acidified influents meaning a reduction in the chemical reactive expense required to control acid pH‐value throughout operation. © 1999 Society of Chemical Industry     

Tilting the Balance: Therapeutic Prospects of CD83 as a Checkpoint Molecule Controlling Resolution of Inflammation

Chronic inflammatory diseases and transplant rejection represent major challenges for modern health care. Thus, identification of immune checkpoints that contribute to resolution of inflammation is key to developing novel therapeutic agents for those conditions. In recent years, the CD83 (cluster of differentiation 83) protein has emerged as an interesting potential candidate for such a “pro-resolution” therapy. This molecule occurs in a membrane-bound and a soluble isoform (mCD83 and sCD83, respectively), both of which are involved in resolution of inflammation. Originally described as a maturation marker on dendritic cells (DCs), mCD83 is also expressed by activated B and T cells as well as regulatory T cells (Tregs) and controls turnover of MHC II molecules in the thymus, and thereby positive selection of CD4⁺ T cells. Additionally, it serves to confine overshooting (auto-)immune responses. Consequently, animals with a conditional deletion of CD83 in DCs or regulatory T cells suffer from impaired resolution of inflammation. Pro-resolving effects of sCD83 became evident in pre-clinical autoimmune and transplantation models, where application of sCD83 reduced disease symptoms and enhanced allograft survival, respectively. Here, we summarize recent advances regarding CD83-mediated resolution of inflammatory responses, its binding partners as well as induced signaling pathways, and emphasize its therapeutic potential for future clinical trials.     

Zur Reaktion von Dicyclopentadiendiepoxid mit Acrylsäure

On the Reaction of Dicyclopentadiene Diepoxide with Acrylic Acid The esterification of dicyclopentadiene diepoxide as a bifunctional epoxide with acrylic acid was investigated. The influence of solvent polarity, reaction temperature and the catalytic system used are discussed. It was found, that the reaction rate increased with increasing solvent polarity. By using tertiary amines as catalysts, only a small catalytic effect was observed. On the contrary, a good catalytic effect was achieved with Lewis-acids. By means of FeCl₃, a vinylester containing epoxide groups and CC-double-bonds is obtained, which polymerizes via various mechanisms.     

Acute Myelogenous Leukemia Cells Secrete Factors that Stimulate Cellular LDL Uptake via Autocrine and Paracrine Mechanisms

Leukemic cells isolated from most patients with acute myelogenous leukemia (AML) have higher low density lipoprotein (LDL) uptake than normal mononuclear blood cells. Little is known, however, about the mechanism behind the elevated LDL uptake. We investigated if AML cells secrete factors that stimulate cellular LDL uptake. Mononuclear blood cells were isolated from peripheral blood from 42 patients with AML at diagnosis. Cellular LDL uptake was determined from the degradation rate of ¹²⁵I-labelled LDL. Conditioned media from AML cells stimulated the LDL degradation in the leukemic cell lines KG1 and HL60, and in isolated AML cells. The stimulatory effect correlated with the LDL degradation in the AML cells directly after isolation from blood. Conditioned media also autostimulated LDL degradation in the AML cells themselves. Concentrations of IL-6 and IL-8 in AML cell conditioned media correlated with the LDL degradation in AML cells directly after isolation from blood. Addition of R-TNF-α, but not IL-6 or IL-8, stimulated LDL degradation in HL60, KG1, and AML cells. The LDL degradation in AML cells could be inhibited by a LDL receptor blocking antibody. AML cells secrete factors that stimulate LDL uptake in a paracrine and autocrine pattern which open up therapeutic possibilities to inhibit the uptake of LDL by administration of antibodies to these factors.     

Ein neuer Standard für die Ausbildung im Fach Mensch-Computer-Interaktion

Das ,,Curriculum für ein Basismodul zur Mensch-Computer-Interaktion (MCI)“ wurde im Sommer 2006 von der Fachgruppe ,,Software-Ergonomie“ in der Gesellschaft für Informatik (GI) vorgestellt und anschlie?end vom Pr?sidium der GI als Empfehlung für Studieng?nge der Informatik angenommen und verabschiedet. Mit diesem Curriculum werden die notwendigen Grundlagen für eine erfolgreiche Ausbildung von Informatikern/-innen und anderen Berufsgruppen im Themenfeld der Software-Ergonomie geschaffen und vereinheitlicht. Des Weiteren soll es zur Konkretisierung der Anforderungen an Bachelor- und Masterstudieng?nge der Informatik dienen. Zudem soll die Akkreditierung von Informatikstudieng?ngen durch dieses Curriculum unterstützt werden.     

The role of perceived enjoyment and social norm in the adoption of technology with network externalities

The emergence of highly interactive media and the increased connectivity among people call for an investigation of usage behaviour of those media. People tend to rely heavily on peer-to-peer interaction influencing the adoption of new media formats that enhance this interactivity. The first explorative phase of this research consists of interviews with experts and focus groups and builds the basis of the proposed framework and measurement model. Then, a Structural Equation Modelling approach is used to assess the relative importance and the strength between different constructs, including perceived enjoyment, social norm, usefulness, ease of use and intention to use. The results indicate that perceived enjoyment and social norm are important antecedents for the adoption of technology with network externalities.     

Quo vadis efficiency analysis of water distribution? A comparative literature review

Recognizing the growing importance of scientific benchmarking in water distribution, we provide a comprehensive survey of the available literature. We begin with a discussion about the (limited) use of benchmarking in the regulation of UK water utilities, and then extend the analysis to regulated water sectors in other countries. We find no clear impact of public or private ownership; instead, the institutional settings appear to be a dominant driver of efficiency. Quality and structural variables are significant parameters; and water losses and population density are also important drivers. Analysis reveals that economies of scale only exist in fragmented water industries, whereas economies of density are omnipresent. We find evidence suggesting important economies of scope (e.g. between water and sewerage). Finally, we summarize the tensions that exist in attempting to measure efficiency in the water industry and draw conclusions about how to improve efficiency analysis in the future.