132 research outputs found

    Anwendung des Penetrationsmodells von Chlorid bei der Beurteilung des Zustands beim Brückenmanagement

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    Although there is a large number of established Bridge Management Systems worldwide, there seems to be a lack of those that utilise the knowledge on material properties and environmental loading. Hence, as a supplement to current practice, the paper examines the use of the chloride ingress model, supported by the International Federation for Structural Concrete, for preliminary assessment in bridge management. The focus is set on analysing application of the model in realistic situations on existing concrete bridges for which the information on material and environmental properties is lacking.Iako se danas diljem svijeta primjenjuju brojni sustavi za gospodarenje mostovima, čini se da ipak nema dovoljno sustava u kojima bi se koristilo znanje o svojstvima materijala i opterećenju iz okoliša. U ovom se radu, kao doprinos sadašnjoj praksi, analizira primjena modela prodora klorida, što podržava Međunarodni savez za betonske konstrukcije, a koristi se za preliminarno ocjenjivanje u okviru gospodarenja mostovima. Prije svega, analizira se primjena modela u realnim situacijama za ocjenu postojećih betonskih mostova za koje ne postoje podaci o materijalima i svojstvima okoliša.Obwohl heute weltweit zahlreiche Brückenmanagementsysteme angewendet werden, scheint es jedoch nicht ausreichend Systeme zu geben, in denen die Kenntnisse über die Materialeigenschaften und die Umweltbelastung angewendet werden. In dieser Abhandlung wird als Beitrag zur aktuellen Praxis die Anwendung des Penetrationsmodells von Chlorid analysiert, was vom Internationalen Verband für Betonkonstruktionen unterstützt wird, und wird als vorläufige Beurteilung im Rahmen des Brückenmanagements angewendet. Zunächst wird die Anwendung des Modells unter realen Bedingungen für die Beurteilung der bestehenden Betonbrücken analysiert, zu denen Daten über die Materialien und die Umwelteigenschaften vorliegen.The authors would like to show their gratitude for the support received during the project “Life – Cycle Assessment for Railway Structures”, funded by the ÖBB-Infrastruktur Bau AG, Vienna. For the support in the analysis of existing standards, authors would like to express special appreciation to Smart Minerals GmbH

    Interferon-γ acutely augments inhibition of neocortical layer 5 pyramidal neurons

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    BACKGROUND: Interferon-γ (IFN-γ, a type II IFN) is present in the central nervous system (CNS) under various conditions. Evidence is emerging that, in addition to its immunological role, IFN-γ modulates neuronal morphology, function, and development in several brain regions. Previously, we have shown that raising levels of IFN-β (a type I IFN) lead to increased neuronal excitability of neocortical layer 5 pyramidal neurons. Because of shared non-canonical signaling pathways of both cytokines, we hypothesized a similar neocortical role of acutely applied IFN-γ. METHODS: We used semi-quantitative RT-PCR, immunoblotting, and immunohistochemistry to analyze neuronal expression of IFN-γ receptors and performed whole-cell patch-clamp recordings in layer 5 pyramidal neurons to investigate sub- and suprathreshold excitability, properties of hyperpolarization-activated cyclic nucleotide-gated current (Ih), and inhibitory neurotransmission under the influence of acutely applied IFN-γ. RESULTS: We show that IFN-γ receptors are present in the membrane of rat's neocortical layer 5 pyramidal neurons. As expected from this and the putative overlap in IFN type I and II alternative signaling pathways, IFN-γ diminished Ih, mirroring the effect of type I IFNs, suggesting a likewise activation of protein kinase C (PKC). In contrast, IFN-γ did neither alter subthreshold nor suprathreshold neuronal excitability, pointing to augmented inhibitory transmission by IFN-γ. Indeed, IFN-γ increased electrically evoked inhibitory postsynaptic currents (IPSCs) on neocortical layer 5 pyramidal neurons. Furthermore, amplitudes of spontaneous IPSCs and miniature IPSCs were elevated by IFN-γ, whereas their frequency remained unchanged. CONCLUSIONS: The expression of IFN-γ receptors on layer 5 neocortical pyramidal neurons together with the acute augmentation of inhibition in the neocortex by direct application of IFN-γ highlights an additional interaction between the CNS and immune system. Our results strengthen our understanding of the role of IFN-γ in neocortical neurotransmission and emphasize its impact beyond its immunological properties, particularly in the pathogenesis of neuropsychiatric disorders

    Impact of 17β-HSD12, the 3-ketoacyl-CoA reductase of long-chain fatty acid synthesis, on breast cancer cell proliferation and migration

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    Metabolic reprogramming of tumor cells involves upregulation of fatty acid (FA) synthesis to support high bioenergetic demands and membrane synthesis. This has been shown for cytosolic synthesis of FAs with up to 16 carbon atoms. Synthesis of long-chain fatty acids (LCFAs), including ω-6 and ω-3 polyunsaturated FAs, takes place at the endoplasmic reticulum. Despite increasing evidence for an important role of LCFAs in cancer, the impact of their synthesis in cancer cell growth has scarcely been studied. Here, we demonstrated that silencing of 17β-hydroxysteroid dehydrogenase type 12 (17β-HSD12), essentially catalyzing the 3-ketoacyl-CoA reduction step in LCFA production, modulates proliferation and migration of breast cancer cells in a cell line-dependent manner. Increased proliferation and migration after 17β-HSD12 knockdown were partly mediated by metabolism of arachidonic acid towards COX2 and CYP1B1-derived eicosanoids. Decreased proliferation was rescued by increased glucose concentration and was preceded by reduced ATP production through oxidative phosphorylation and spare respiratory capacity. In addition, 17β-HSD12 silencing was accompanied by alterations in unfolded protein response, including a decrease in CHOP expression and increase in eIF2α activation and the folding chaperone ERp44. Our study highlights the significance of LCFA biosynthesis for tumor cell physiology and unveils unknown aspects of breast cancer cell heterogeneity

    Designing Cathodes and Cathode Active Materials for Solid‐State Batteries

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    Solid-state batteries (SSBs) currently attract great attention as a potentially safe electrochemical high-energy storage concept. However, several issues still prevent SSBs from outperforming today\u27s lithium-ion batteries based on liquid electrolytes. One major challenge is related to the design of cathode active materials (CAMs) that are compatible with the superionic solid electrolytes (SEs) of interest. This perspective, gives a brief overview of the required properties and possible challenges for inorganic CAMs employed in SSBs, and describes state-of-the art solutions. In particular, the issue of tailoring CAMs is structured into challenges arising on the cathode-, particle-, and interface-level, related to microstructural, (chemo-)mechanical, and (electro-)chemical interplay of CAMs with SEs, and finally guidelines for future CAM development for SSBs are proposed

    Gamma prediction models for long-term creep deformations of prestressed concrete bridges

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    For long-span bridges as well as statically indeterminate frame structures it is essential to implement efficient and realistic prediction models for the long-term processes of concrete creep, shrinkage, and steel relaxation. In order to systematically study the main influential factors in bridge deflection measurements a probabilistic analysis can be per­formed. Due to the associated computational costs such investigations are limited. The predictions based on the highly scattered input parameters are associated with uncertainties. There is interest in alternative prediction models decou­pled from complex analytical and computationally expensive numerical models, using measured structural responses. A gamma process is an example of such an alternative method. This process is suitable for capturing evolving structural response quantities and deterioration mechanisms like crack propagation, corrosion, creep, and shrinkage, as reported in Ohadi and Micic (2011). The objective of this paper is to illustrate the use of gamma process approaches for the pre­diction of the creep and shrinkage performance of prestressed concrete bridges. The presented approaches incorporate uncertainties and make predictions more reliable with the help of structural health monitoring (SHM) data. The creep-shrinkage response of a prestressed box girder bridge serves for the calibration and evaluation of the considered gamma process approaches

    How special are Brightest Group and Cluster Galaxies?

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    We use the Sloan Digital Sky Survey to construct a sample of 625 brightest group and cluster galaxies (BCGs) together with control samples of non-BCGs matched in stellar mass, redshift, and color. We investigate how the systematic properties of BCGs depend on stellar mass and on their privileged location near the cluster center. The groups and clusters that we study are drawn from the C4 catalogue of Miller et al. (2005) but we have developed improved algorithms for identifying the BCG and for measuring the cluster velocity dispersion. Since the SDSS photometric pipeline tends to underestimate the luminosities of large galaxies in dense environments, we have developed a correction for this effect which can be readily applied to the published catalog data. We find that BCGs are larger and have higher velocity dispersions than non-BCGs of the same stellar mass, which implies that BCGs contain a larger fraction of dark matter. In contrast to non-BCGs, the dynamical mass-to-light ratio of BCGs does not vary as a function of galaxy luminosity. Hence BCGs lie on a different fundamental plane than ordinary elliptical galaxies. BCGs also follow a steeper Faber-Jackson relation than non-BCGs, as suggested by models in which BCGs assemble via dissipationless mergers along preferentially radial orbits. We find tentative evidence that this steepening is stronger in more massive clusters. BCGs have similar mean stellar ages and metallicities to non-BCGs of the same mass, but they have somewhat higher alpha/Fe ratios, indicating that star formation may have occurred over a shorter timescale in the BCGs. Finally, we find that BCGs are more likely to host radio-loud active galactic nuclei than other galaxies of the same mass, but are less likely to host an optical AGN. The differences we find are more pronounced for the less massive BCGs.Comment: Replaced with slightly modified version accepted by MNRAS. 28 pages, 25 figures. Version with full resolution figures available at http://www.mpa-garching.mpg.de/~anja/bcgs_avdl.pd

    Virulence and antimicrobial resistance determinants of verotoxigenic Escherichia coli (VTEC) and of ESBL-producing multidrug resistant E. coli from foods of animal origin illegally imported to Europe

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    Microbial risk due to illegal food import has not been investigated so far. Here we aimed to reveal frequency, phenotype and genotype of verotoxigenic E. coli (VTEC) and ESBL-producing multidrug resistant (MDR) E. coli isolated from foods of animal origin confiscated at the EU airport borders. Of the 1500 food samples confiscated at the airports of Austria, Germany and Slovenia, the most frequent were cheese and meat products primarily from Turkey and from Balkan countries. The VTEC bacteria were isolated using ISO 16654:2001 for O157 and Ridascreen® ELISA based PCR testing of stx genes or ISO/ TS13136 for non-O157 VTEC, resulting in 15 isolates of VTEC (1%). In addition 600 samples from the Vienna airport were also tested for ESBL-producing MDR E. coli, using cefotaxime-McConkey agar. We identified 14 E. coli strains as ESBL/MDR E. coli. (0,9%) for phenotyping for antimicrobial resistance and for genotypiing by microarray (Identibac®,AMR05). The 15 VTEC isolates were phenotyped as Stx toxin producing non-O157 strain. Only one isolate, from Turkish cheese, proved to be EHEC (O26:H46). The remaining 14 strains represent uncommon VTEC serotypes with stx1 and/or stx2 genes. Microarray analysis (Identibac®, Ec03) revealed a wide range of other non-LEE encoding virulence genes. Pulsed field electrophoresis (PFGE) showed high genetic diversity of the strains. Multilocus sequence typing (MLST) established three new ST types (ST4505, 4506 and 4507) in the MLST database, and indicated the existence of 5 small clusters with no relation to origin or serotype/genotype of the strains, but representing several human-related ST types. All VTEC isolates were sensitive to 18 antimicrobials relevant to human and/or animal health, and did not contain resistance genes. ESB/MDR E. coli were resistant to at least 3 classes of antimicrobials. Microarray analysis detected TEM-1 in all but one strain and a variety of genes encoding resistances to other ESBLs (CTXM-1, OXA-1), trimethromprim, tetracycline, aminoglycosides and class1/class2 integrons (8/14 isolates). E.coli virulence microarray detected 2-6 virulence genes in all but one MDR E. coli, and one of the strains qualified as an atypical EPEC . Even though the frequency and attributes of isolated VTEC and ESBL/MDR E. coli did not represent an immediate major risk through illegal food import for the countries involved, it is suggested that the unusual serovars of VTEC as well as the virulence and antimicrobial resistance determinants of ESBL/MDR E. coli detected here, may indicate a future emerging threat by strains in illegally imported foods. Acknowledgement is due to: EU FP7 PROMISE (Grant No: 265877), to Dr. Mária Herpay, National Institute for Epidemiology, Budapest

    Suppression of grasshopper sound production by nitric oxide-releasing neurons of the central complex

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    The central complex of acridid grasshoppers integrates sensory information pertinent to reproduction-related acoustic communication. Activation of nitric oxide (NO)/cyclic GMP-signaling by injection of NO donors into the central complex of restrained Chorthippus biguttulus females suppresses muscarine-stimulated sound production. In contrast, sound production is released by aminoguanidine (AG)-mediated inhibition of nitric oxide synthase (NOS) in the central body, suggesting a basal release of NO that suppresses singing in this situation. Using anti-citrulline immunocytochemistry to detect recent NO production, subtypes of columnar neurons with somata located in the pars intercerebralis and tangential neurons with somata in the ventro-median protocerebrum were distinctly labeled. Their arborizations in the central body upper division overlap with expression patterns for NOS and with the site of injection where NO donors suppress sound production. Systemic application of AG increases the responsiveness of unrestrained females to male calling songs. Identical treatment with the NOS inhibitor that increased male song-stimulated sound production in females induced a marked reduction of citrulline accumulation in central complex columnar and tangential neurons. We conclude that behavioral situations that are unfavorable for sound production (like being restrained) activate NOS-expressing central body neurons to release NO and elevate the behavioral threshold for sound production in female grasshoppers

    Reconstructing the Deep Population History of Central and South America

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    We report genome-wide ancient DNA from 49 individuals forming four parallel time transects in Belize, Brazil, the Central Andes, and the Southern Cone, each dating to at least 9,000 years ago. The common ancestral population radiated rapidly from just one of the two early branches that contributed to Native Americans today. We document two previously unappreciated streams of gene flow between North and South America. One affected the Central Andes by 4,200 years ago, while the other explains an affinity between the oldest North American genome associated with the Clovis culture and the oldest Central and South Americans from Chile, Brazil, and Belize. However, this was not the primary source for later South Americans, as the other ancient individuals derive from lineages without specific affinity to the Clovis-associated genome, suggesting a population replacement that began at least 9,000 years ago and was followed by substantial population continuity in multiple regions
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