133 research outputs found

    A smoothed stochastic earthquake rate model considering seismicity and fault moment release for Europe

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    We present a time-independent gridded earthquake rate forecast for the European region including Turkey. The spatial component of our model is based on kernel density estimation techniques, which we applied to both past earthquake locations and fault moment release on mapped crustal faults and subduction zone interfaces with assigned slip rates. Our forecast relies on the assumption that the locations of past seismicity is a good guide to future seismicity, and that future large-magnitude events occur more likely in the vicinity of known faults. We show that the optimal weighted sum of the corresponding two spatial densities depends on the magnitude range considered. The kernel bandwidths and density weighting function are optimized using retrospective likelihood-based forecast experiments. We computed earthquake activity rates (a- and b-value) of the truncated Gutenberg-Richter distribution separately for crustal and subduction seismicity based on a maximum likelihood approach that considers the spatial and temporal completeness history of the catalogue. The final annual rate of our forecast is purely driven by the maximum likelihood fit of activity rates to the catalogue data, whereas its spatial component incorporates contributions from both earthquake and fault moment-rate densities. Our model constitutes one branch of the earthquake source model logic tree of the 2013 European seismic hazard model released by the EU-FP7 project ‘Seismic HAzard haRmonization in Europe' (SHARE) and contributes to the assessment of epistemic uncertainties in earthquake activity rates. We performed retrospective and pseudo-prospective likelihood consistency tests to underline the reliability of our model and SHARE's area source model (ASM) using the testing algorithms applied in the collaboratory for the study of earthquake predictability (CSEP). We comparatively tested our model's forecasting skill against the ASM and find a statistically significant better performance for testing periods of 10-20yr. The testing results suggest that our model is a viable candidate model to serve for long-term forecasting on timescales of years to decades for the European regio

    The influence of palatal harvesting technique on the donor site vascular injury: A splitâ mouth comparative cadaver study

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    BackgroundThe aim of this study was to evaluate the influence of two harvesting approaches on the donor site vascular injury.MethodsA splitâ mouth cadaver study was designed on 21 fresh donor heads. Every hemiâ palate was assigned to receive the trapâ door harvesting technique (TDT) or the epithelialized free gingival graft harvesting technique (FGGT). A soft tissue graft was harvested from each side for histology analyses. Betadine solution was used to inject the external carotid artery and a collagen sponge was positioned over the harvested area to compare the amount of â leakage.â ResultsThe mean leakage observed was 16.56 ± 3.01 µL in the FGGTâ harvested sites, and 69.21 ± 7.08 µL for the TDT group, a ratio of 4.18 (P < 0.01). Regression analyses demonstrated a trend for more leakage at thinner palatal sites for the FGGT group (P = 0.09), and a statistically significant correlation for the TDTâ harvest sites (P = 0.02). Additionally, a shallow palatal vault height (PVH) was associated with a higher leakage in both harvesting groups (P = 0.02). The histomorphometric analyses revealed that grafts harvested with TDT exhibited a significantly higher mean number of medium (ø = 0.1 to 0.5 mm, P = 0.03), and large vessels (ø â ¥ 0.5 mm, P = 0.02).ConclusionsWithin the limitations of the present research, the TDT resulted in a significantly higher leakage than the FGGT, which was also correlated with the histology analyses where a greater number of medium and large vessels were observed in the harvested grafts.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153658/1/jper10394.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153658/2/jper10394_am.pd

    Endothelial cell-derived interleukin-6 regulates tumor growth

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    Abstract Background Endothelial cells play a complex role in the pathobiology of cancer. This role is not limited to the making of blood vessels to allow for influx of oxygen and nutrients required for the high metabolic demands of tumor cells. Indeed, it has been recently shown that tumor-associated endothelial cells secrete molecules that enhance tumor cell survival and cancer stem cell self-renewal. The hypothesis underlying this work is that specific disruption of endothelial cell-initiated signaling inhibits tumor growth. Methods Conditioned medium from primary human dermal microvascular endothelial cells (HDMEC) stably transduced with silencing RNA for IL-6 (or controls) was used to evaluate the role of endothelial-derived IL-6 on the activation of key signaling pathways in tumor cells. In addition, these endothelial cells were co-transplanted with tumor cells into immunodefficient mice to determine the impact of endothelial cell-derived IL-6 on tumor growth and angiogenesis. Results We observed that tumor cells adjacent to blood vessels show strong phosphorylation of STAT3, a key mediator of tumor progression. In search for a possible mechanism for the activation of the STAT3 signaling pathway, we observed that silencing interleukin (IL)-6 in tumor-associated endothelial cells inhibited STAT3 phosphorylation in tumor cells. Notably, tumors vascularized with IL-6-silenced endothelial cells showed lower intratumoral microvessel density, lower tumor cell proliferation, and slower growth than tumors vascularized with control endothelial cells. Conclusions Collectively, these results demonstrate that IL-6 secreted by endothelial cells enhance tumor growth, and suggest that cancer patients might benefit from targeted approaches that block signaling events initiated by endothelial cells.http://deepblue.lib.umich.edu/bitstream/2027.42/109499/1/12885_2013_Article_4365.pd

    RESEARCH ON THE WORKING PROCESS OPTIMIZATION OF A COMBINED INSTALLATION FOR GRAINS CLEANING

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    This paper presents experimental research of qualitative indexes of impurities separation out of grains seeds for one installation which used combined principles of separation (according to specific mass and aerodynamic properties of seeds). The installation used on the experimental research was composed of a gravity separator and an aspiration installation. Based on data obtained by measurements and regulated qualitative indicators the cleaning process indexes have been determined

    Myasthenia Gravis – a beginning with no end

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    Myasthenia gravis is one of the neurological diseases with a relatively recent history, full of mistakes, in which the British and German neurology schools have attempted to find answers when confronted with the unknown. The paper aims at making a historical account of the disease from its discovery in the 16th century, when the first case of myasthenia gravis was medically diagnosed, to the beginning of the 20th century, when the dawn of modern therapy started to show

    Human Very Small Embryonic-Like Cells Generate Skeletal Structures, In Vivo

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    Human very small embryonic-like (hVSEL) cells are a resident population of multipotent stem cells in the bone marrow involved in the turnover and regeneration of tissues. The levels of VSEL cells in blood are greatly increased in response to injury, and they have been shown to repair injured tissues. Adult hVSEL cells, SSEA-4+/CD133+/CXCR4+/Lin?/CD45?, express the pluripotency markers (Oct-4 and Nanog) and may be able to differentiate into cells from all 3 germ lineages. hVSEL cells isolated from blood by apheresis following granulocyte?colony-stimulating factor mobilization were fractionated and enriched by elutriation and fluorescence activated cell sorting. Collagen sponge scaffolds containing 2,000?30,000 hVSEL cells were implanted into cranial defects generated in SCID mice. Analysis by microcomputed tomography showed that a cell population containing VSEL cells produced mineralized tissue within the cranial defects compared with controls at 3 months. Histologic studies showed significant bone formation and cellular organization within the defects compared with cellular or scaffold controls alone. Antibodies to human leukocyte antigens demonstrated that the newly generated tissues were of human origin. Moreover, human osteocalcin was identified circulating in the peripheral blood. There was evidence that some level of hVSEL cells migrated away from the defect site, using quantitative real-time polymerase chain reaction to detect for human-specific Alu sequences. This study demonstrates that hVSEL cells are able to generate human bone tissue in a mouse model of skeletal repair. These studies lay the foundation for future cell-based regenerative therapies for osseous and connective tissue disorders, including trauma and degenerative conditions, such as osteoporosis, fracture repair, and neoplastic repair.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140198/1/scd.2012.0327.pd

    Phosphorylation controls autoinhibition of cytoplasmic linker protein-170

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    Author Posting. © American Society for Cell Biology, 2010. This article is posted here by permission of American Society for Cell Biology for personal use, not for redistribution. The definitive version was published in Molecular Biology of the Cell 21 (2010): 2661-2673, doi:10.1091/mbc.E09-12-1036.Cytoplasmic linker protein (CLIP)-170 is a microtubule (MT) plus-end-tracking protein that regulates MT dynamics and links MT plus ends to different intracellular structures. We have shown previously that intramolecular association between the N and C termini results in autoinhibition of CLIP-170, thus altering its binding to MTs and the dynactin subunit p150Glued (J. Cell Biol. 2004: 166, 1003–1014). In this study, we demonstrate that conformational changes in CLIP-170 are regulated by phosphorylation that enhances the affinity between the N- and C-terminal domains. By using site-directed mutagenesis and phosphoproteomic analysis, we mapped the phosphorylation sites in the third serine-rich region of CLIP-170. A phosphorylation-deficient mutant of CLIP-170 displays an "open" conformation and a higher binding affinity for growing MT ends and p150Glued as compared with nonmutated protein, whereas a phosphomimetic mutant confined to the "folded back" conformation shows decreased MT association and does not interact with p150Glued. We conclude that phosphorylation regulates CLIP-170 conformational changes resulting in its autoinhibition.This work was supported by National Institutes of Health grant GM-25062 (to G.G.B.); Netherlands Organization for Scientific Research grants (to A. A. and N. G.); a Cancer Genomics Centre grant (to J.v.H.); and Presidential Program of Russian Academy of Sciences and RFBP grant 05-04-4915 (to E.S.N.)

    TESTING THE RESISTANCE STRUCTURES OF TRACTORS AND AGRICULTURAL MACHINERY UNDER SIMULATED AND ACCELERATED REGIME

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    The need for an increased quality of products, the reduction of the production entry time and the restrictions imposed by the service period of products are the essential reasons which impose the necessity of using the simulated and accelerated regime tests. An accelerated test is necessary to produce the same content of wear deterioration as that one supported by the product (machine, gear, subsystem or component) on its lifetime in normal functioning conditions. Although a test in accelerated regime doesn`t have to produce big loads, unrealistic, which could alter the defecting mechanism? The paper presents the principal methods of test acceleration and exemplifies the test in accelerated and simulated regime by a test of endurance effectuated on the structure of a two plough body, on the Hydropulse stand inside of Testing Department from INMA Bucharest. Also, the paper present photos that were taken during the years from tests in simulated and accelerated regime, on the Hydropulse stand, of different machines and agricultural gears

    Monitoraggio in area sismica di beni monumentali: tecniche NDT e procedure di verifica

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    Negli ultimi anni il concetto di vulnerabilità sismica è tristemente entrato a far parte delle conoscenze anche dei non addetti ai lavori. Infatti, gli eventi sismici che hanno interessato dagli inizi del ‘900 il territorio Italiano, hanno sistematicamente messo in risalto l’elevata vulnerabilità sismica del nostro patrimonio edilizio, ivi compresi i beni monumentali, nonché, l’inesistenza di qualsiasi attività di programmazione della manutenzione periodica ordinaria e straordinaria delle strutture sismo-resistenti, che garantiscono nel tempo la conservazione delle loro capacità di risposta alle perturbazioni esterne.Il progetto PON sul Monitoraggio in Area Sismica di SIstemi MOnumentali nasce con la prerogativa di produrre uno strumento dedicato alla tutela di strutture a valenza storico – artistica, attraverso un percorso di catalogazione, di analisi del bene inteso come elemento costituito da elementi resistenti e da materiali, di studio del sito dove la struttura è ubicata e di attività di monitoraggio

    The 2013 European Seismic Hazard Model: key components and results

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    The 2013 European Seismic Hazard Model (ESHM13) results from a community-based probabilistic seismic hazard assessment supported by the EU-FP7 project “Seismic Hazard Harmonization in Europe” (SHARE, 2009–2013). The ESHM13 is a consistent seismic hazard model for Europe and Turkey which overcomes the limitation of national borders and includes a through quantification of the uncertainties. It is the first completed regional effort contributing to the “Global Earthquake Model” initiative. It might serve as a reference model for various applications, from earthquake preparedness to earthquake risk mitigation strategies, including the update of the European seismic regulations for building design (Eurocode 8), and thus it is useful for future safety assessment and improvement of private and public buildings. Although its results constitute a reference for Europe, they do not replace the existing national design regulations that are in place for seismic design and construction of buildings. The ESHM13 represents a significant improvement compared to previous efforts as it is based on (1) the compilation of updated and harmonised versions of the databases required for probabilistic seismic hazard assessment, (2) the adoption of standard procedures and robust methods, especially for expert elicitation and consensus building among hundreds of European experts, (3) the multi-disciplinary input from all branches of earthquake science and engineering, (4) the direct involvement of the CEN/TC250/SC8 committee in defining output specifications relevant for Eurocode 8 and (5) the accounting for epistemic uncertainties of model components and hazard results. Furthermore, enormous effort was devoted to transparently document and ensure open availability of all data, results and methods through the European Facility for Earthquake Hazard and Risk (www.​efehr.​org)
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