109 research outputs found

    Конкурентоспроможність машинобудівних підприємств на ринку залізничного рухомого складу

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    Охарактеризовано распределение производственных мощностей и потребителей вагоно-строительной продукции на экономических рынках СНГ. Дана оценка конкурентной среды в подотрасли машиностроения железнодорожного подвижного состава на макро и микроуровне, выявлены факторы риска и обоснованы мероприятия, ориентированные на укрепление конкурентоспособности исследуемых предприятий. Ключевые слова: машиностроительное предприятие, конкурентоспособность, рынок, железнодорожный подвижной состав.Охарактеризовано розподіл виробничих потужностей і споживачів вагонобудівної продукції на економічних ринках СНД. Наведено оцінку конкурентного середовища в підгалузі маши-нобудування залізничного рухомого складу на макро і мікрорівні, виявлено фактори ризику й обґрунтовано заходи, орієнтовані на зміцнення конкурентоспроможності досліджуваних підприємств. Ключові слова: машинобудівне підприємство, конкурентоспроможність, ринок, залізничний рухомий склад.The paper characterizes production capacities and consumers of wagon products on the economic markets of CIS countries. The competition environment in the sector of railway rolling stock building on macro and micro-level was assessed, the factors of risk were identified, and measures oriented to streng-thening the competitiveness of the enterprises under investigation are well-grounded. Keywords: machine-building enterprise, competitiveness, market, railway rolling stock

    Dependence of late glacial sea-level predictions on 3D Earth structure

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    Glacial isostatic adjustment is dominated by Earth rheology resulting in a variability of relative sea-level (RSL) predictions of more than 100 meters during the last glacial cycle. Seismic tomography models reveal significant lateral variations in seismic wavespeed, most likely corresponding to variations in temperature and hence viscosity. Therefore, the replacement of 1D Earth structures by a 3D Earth structure is an essential part of recent research to reveal the impact of lateral viscosity contrasts and to achieve a more consistent view on solid-Earth dynamics. Here, we apply the VIscoelastic Lithosphere and MAntle model VILMA to predict RSL during the last deglaciation. We create an ensemble of geodynamically constrained 3D Earth structures which is based on seismic tomography models while considering a range of conversion factors to transfer seismic velocity variations into viscosity variations. For a number of globally distributed sites, we discuss the resulting variability in RSL predictions, compare this with regionally optimized 1D Earth structures, and validate the model results with relative sea-level data (sea-level indicators). This study is part of the German Climate Modeling initiative PalMod aiming the modeling of the last glacial cycle under consideration of a coupled Earth system model, i.e. including feedbacks between ice-sheets and the solid Earth

    How to erase surface plasmon fringes

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    We report the realization of a dual surface plasmon polariton (SPP) microscope based on leakage radiation (LR) analysis. The microscope can either image SPP propagation in the direct space or tin the Fourier space. This particularity allows in turn manipulation of the LR image for a clear separation of different interfering SPP contributions present close to optical nanoelements.Comment: Appl. Phys. Lett. 89, 091117 (2006

    Global plate motion frames: Toward a unified model

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94772/1/rog1664.pd

    Subduction and continental collision in the Eastern Mediterranean during the closure of the Tethyan gateway

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    Plate tectonics and mantle dynamics controlled the continental collision and tectonics of the Eastern Mediterranean – Tethyan realm, including by closing the Tethys Seaway linking the Atlantic and Indo-Pacific oceans. This led to reorganizations in ocean circulation, diversification and migration of marine and terrestrial species, and climatic change. Here, I review some of the work on the geodynamics of the region, including on the evolution of topography, and how paleotopography was influenced by mantle convection and volcanism. Mantle convection appears to have had a significant impact on the paleoenvironment, including by ultimately establishing the Gomphotherium Landbridge in the Miocene, enabling greater faunal exchanges between Africa-Arabia and Eurasia

    Effects of upper mantle heterogeneities on the lithospheric stress field and dynamic topography

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    The orientation and tectonic regime of the observed crustal/lithospheric stress field contribute to our knowledge of different deformation processes occurring within the Earth's crust and lithosphere. In this study, we analyze the influence of the thermal and density structure of the upper mantle on the lithospheric stress field and topography. We use a 3-D lithosphere–asthenosphere numerical model with power-law rheology, coupled to a spectral mantle flow code at 300 km depth. Our results are validated against the World Stress Map 2016 (WSM2016) and the observation-based residual topography. We derive the upper mantle thermal structure from either a heat flow model combined with a seafloor age model (TM1) or a global S-wave velocity model (TM2). We show that lateral density heterogeneities in the upper 300 km have a limited influence on the modeled horizontal stress field as opposed to the resulting dynamic topography that appears more sensitive to such heterogeneities. The modeled stress field directions, using only the mantle heterogeneities below 300 km, are not perturbed much when the effects of lithosphere and crust above 300 km are added. In contrast, modeled stress magnitudes and dynamic topography are to a greater extent controlled by the upper mantle density structure. After correction for the chemical depletion of continents, the TM2 model leads to a much better fit with the observed residual topography giving a good correlation of 0.51 in continents, but this correction leads to no significant improvement of the fit between the WSM2016 and the resulting lithosphere stresses. In continental regions with abundant heat flow data, TM1 results in relatively small angular misfits. For example, in western Europe the misfit between the modeled and observation-based stress is 18.3°. Our findings emphasize that the relative contributions coming from shallow and deep mantle dynamic forces are quite different for the lithospheric stress field and dynamic topography

    Continental crust beneath southeast Iceland

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    The magmatic activity (0–16 Ma) in Iceland is linked to a deep mantle plume that has been active for the past 62 My. Icelandic and northeast Atlantic basalts contain variable proportions of two enriched components, interpreted as recycled oceanic crust supplied by the plume, and subcontinental lithospheric mantle derived from the nearby continental margins. A restricted area in southeast Iceland—and especially the Öræfajökull volcano—is characterized by a unique enriched-mantle component (EM2-like) with elevated 87Sr/86Sr and 207Pb/204Pb. Here, we demonstrate through modeling of Sr–Nd–Pb abundances and isotope ratios that the primitive Öræfajökull melts could have assimilated 2–6% of underlying continental crust before differentiating to more evolved melts. From inversion of gravity anomaly data (crustal thickness), analysis of regional magnetic data, and plate reconstructions, we propose that continental crust beneath southeast Iceland is part of ∼350-km-long and 70-km-wide extension of the Jan Mayen Microcontinent (JMM). The extended JMM was marginal to East Greenland but detached in the Early Eocene (between 52 and 47 Mya); by the Oligocene (27 Mya), all parts of the JMM permanently became part of the Eurasian plate following a westward ridge jump in the direction of the Iceland plume

    The small molecule inhibitor BX-795 uncouples IL-2 production from inhibition of Th2 inflammation and induces CD4+ T cells resembling iTreg

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    BackgroundTreg cells have been shown to be an important part of immune-homeostasis and IL-2 which is produced upon T cell receptor (TCR)-dependent activation of T lymphocytes has been demonstrated to critically participate in Treg development.ObjectiveTo evaluate small molecule inhibitors (SMI) for the identification of novel IL-2/Treg enhancing compounds.Materials and methodsWe used TCR-dependent and allergen-specific cytokine secretion of human and mouse T cells, next generation messenger ribonucleic acid sequencing (RNA-Seq) and two different models of allergic airway inflammation to examine lead SMI-compounds.ResultsWe show here that the reported 3-phosphoinositide dependent kinase-1 (PDK1) SMI BX-795 increased IL-2 in culture supernatants of Jurkat E6-1 T cells, human peripheral blood mononuclear cells (hPBMC) and allergen-specific mouse T cells upon TCR-dependent and allergen-specific stimulation while concomitantly inhibiting Th2 cytokine secretion. RNA-Seq revealed that the presence of BX-795 during allergen-specific activation of T cells induces a bona fide Treg cell type highly similar to iTreg but lacking Foxp3 expression. When applied in mugwort pollen and house dust mite extract-based models of airway inflammation, BX-795 significantly inhibited Th2 inflammation including expression of Th2 signature transcription factors and cytokines and influx into the lungs of type 2-associated inflammatory cells such as eosinophils.ConclusionsBX-795 potently uncouples IL-2 production from Th2 inflammation and induces Th-IL-2 cells, which highly resemble induced (i)Tregs. Thus, BX-795 may be a useful new compound for the treatment of allergic diseases
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