Systematic Approach for Finite Element Analysis of Thermoplastic Impregnated 3D Filament Winding Structures—Advancements and Validation

This work aims to enhance and validate a systematic approach for the structural finite element (FE) analysis of thermoplastic impregnated 3D filament winding structures (fiber skeletons). The idealized modeling of geometrically complex fiber skeletons used in previous publications is refined by considering additional characteristic dimensions and investigating their mechanical influence. Moreover, the modeling approach is transferred from the meso- to the macro-level in order to reduce modeling and computational effort. The properties of meso- and macro-level FE models are compared using the example of simple loop specimens. Based on the results, respective application fields are defined. In the next step, the same modeling approach is applied to a more complex, three-dimensional specimen—the inclined loop. For its macro-level FE model, additional material characterization and modeling, as well as enhancements in the modeling of the geometry, are proposed. Together with previously determined effective composite properties of fiber skeletons, these results are validated in experimental tensile tests on inclined loop specimens

Optimizing care for the obese patient in interventional radiology

With the rising epidemic of obesity, interventional radiologists are treating increasing numbers of obese patients, as comorbidities associated with obesity preclude more invasive treatments. These patients are at heightened risk of vascular and oncologic disease, both of which often require interventional radiology care. Obese patients pose unique challenges in imaging, technical feasibility, and periprocedural monitoring. This review describes the technical and clinical challenges posed by this population, with proposed methods to mitigate these challenges and optimize care

Beyond equilibrium: Re-evaluating physical modelling of fluvial systems to represent climate changes

© 2018 Elsevier B.V. The interactions between water, sediment and biology in fluvial systems are complex and driven by multiple forcing mechanisms across a range of spatial and temporal scales. In a changing climate, some meteorological drivers are expected to become more extreme with, for example, more prolonged droughts or more frequent flooding. Such environmental changes will potentially have significant consequences for the human populations and ecosystems that are dependent on riverscapes, but our understanding of fluvial system response to external drivers remains incomplete. As a consequence, many of the predictions of the effects of climate change have a large uncertainty that hampers effective management of fluvial environments. Amongst the array of methodological approaches available to scientists and engineers charged with improving that understanding, is physical modelling. Here, we review the role of physical modelling for understanding both biotic and abiotic processes and their interactions in fluvial systems. The approaches currently employed for scaling and representing fluvial processes in physical models are explored, from 1:1 experiments that reproduce processes at real-time or time scales of 10 −1 -10 0 years, to analogue models that compress spatial scales to simulate processes over time scales exceeding 10 2 –10 3 years. An important gap in existing capabilities identified in this study is the representation of fluvial systems over time scales relevant for managing the immediate impacts of global climatic change; 10 1 – 10 2 years, the representation of variable forcing (e.g. storms), and the representation of biological processes. Research to fill this knowledge gap is proposed, including examples of how the time scale of study in directly scaled models could be extended and the time scale of landscape models could be compressed in the future, through the use of lightweight sediments, and innovative approaches for representing vegetation and biostabilisation in fluvial environments at condensed time scales, such as small-scale vegetation, plastic plants and polymers. It is argued that by improving physical modelling capabilities and coupling physical and numerical models, it should be possible to improve understanding of the complex interactions and processes induced by variable forcing within fluvial systems over a broader range of time scales. This will enable policymakers and environmental managers to help reduce and mitigate the risks associated with the impacts of climate change in rivers

Beam feasibility study of a collimator with in-jaw beam position monitors

At present, the beam-based alignment of the LHC collimators is performed by touching the beam halo with both jaws of each collimator. This method requires dedicated fills at low intensities that are done infrequently and makes this procedure time consuming. This limits the operational flexibility, in particular in the case of changes of optics and orbit configuration in the experimental regions. The performance of the LHC collimation system relies on the machine reproducibility and regular loss maps to validate the settings of the collimator jaws. To overcome these limitations and to allow a continuous monitoring of the beam position at the collimators, a design with jaw-integrated Beam Position Monitors (BPMs) was proposed and successfully tested with a prototype (mock-up) collimator in the CERN SPS. Extensive beam experiments allowed to determine the achievable accuracy of the jaw alignment for single and multi-turn operation. In this paper, the results of these experiments are discussed. The non-linear response of the BPMs is compared to the predictions from electromagnetic simulations. Finally, the measured alignment accuracy is compared to the one achieved with the present collimators in the LHC.peer-reviewe

Tick-borne Encephalitis from Eating Goat Cheese in a Mountain Region of Austria

We report transmission of tick-borne encephalitis virus (TBEV) in July 2008 through nonpasteurized goat milk to 6 humans and 4 domestic pigs in an alpine pasture 1,500 m above sea level. This outbreak indicates the emergence of ticks and TBEV at increasing altitudes in central Europe and the efficiency of oral transmission of TBEV

H-Ras Activation Promotes Cytoplasmic Accumulation and Phosphoinositide 3-Oh Kinase Association of β-Catenin in Epidermal Keratinocytes

The mechanisms underlying downregulation of the cadherin/catenin complexes and β-catenin signaling during tumor progression are not fully understood. We have analyzed the effect of oncogenic H-Ras on E-cadherin/catenin complex formation/stabilization and β-catenin distribution in epidermal keratinocytes. Microinjection or stable expression of V12Ras into keratinocytes promotes the loss of E-cadherin and α-catenin and relocalization of β-catenin to the cytoplasm and nucleus. Moreover, these effects are dependent on PI3K (phosphoinositide 3-OH kinase) activity. Interestingly, a strong association of p85α and p110α subunits of PI3K with β-catenin is induced in V12Ras-expressing keratinocytes, and in vitro binding assays show a direct interaction between β-catenin and p85α. Overexpression of either V12Ras or constitutively active p110α induces metabolic stabilization of β-catenin and promotes its accumulation in cytoplasmic and nuclear pools. In addition, the interaction of β-catenin with the adenomatous polyposis coli protein is blocked in V12Ras and p110α transformants though no changes in glycogen synthase kinase 3 β activity could be detected. Nevertheless, in V12Ras transformants the in vivo phosphorylation of β-catenin in Ser residues is strongly decreased. These results indicate that H-Ras activation induces the relocalization and cytoplasmic stabilization of β-catenin by a mechanism involving its interaction with PI3K

The juxtamembrane region of the cadherin cytoplasmic tail supports lateral clustering, adhesive strengthening, and interaction with p129(ctn)

Cadherin cell-cell adhesion molecules form membrane-spanning molecular complexes that couple homophilic binding by the cadherin ectodomain to the actin cytoskeleton. A fundamental issue in cadherin biology is how this complex converts the weak intrinsic binding activity of the ectodomain into strong adhesion. Recently we demonstrated that cellular cadherins cluster in a ligand-dependent fashion when cells attached to substrata coated with the adhesive ectodomain of Xenopus C-cadherin (CEC1-5). Moreover, forced clustering of the ectodomain alone significantly strengthened adhesiveness (Yap, A.S., W.M. Brieher, M. Pruschy, and B.M. Gumbiner. Curr. Biol. 7:308-315). In this study we sought to identify the determinants of the cadherin cytoplasmic tail responsible for clustering activity. A deletion mutant of C-cadherin (CT669) that retained the juxtamembrane 94-amino acid region of the cytoplasmic tail, but not the beta-catenin-binding domain, clustered upon attachment to substrata coated with CEC1-5. Like wild-type C-cadherin, this clustering was Ligand dependent. In contrast, mutant molecules lacking either the complete cytoplasmic tail or just the juxtamembrane region did not cluster. The juxtamembrane region was itself sufficient to induce clustering when fused to a heterologous membrane-anchored protein, albeit in a ligand-independent fashion. The CT669 cadherin mutant also displayed significant adhesive activity when tested in laminar flow detachment assays and aggregation assays. Purification of proteins binding to the juxtamembrane region revealed that the major associated protein is p120(ctn). These findings identify the juxtamembrane region of the cadherin cytoplasmic tail as a functionally active region supporting cadherin clustering and adhesive strength and raise the possibility that p120(ctn) is involved in clustering and cell adhesion