212 research outputs found

    The QUIC Fix for Optimal Video Streaming

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    Within a few years of its introduction, QUIC has gained traction: a significant chunk of traffic is now delivered over QUIC. The networking community is actively engaged in debating the fairness, performance, and applicability of QUIC for various use cases, but these debates are centered around a narrow, common theme: how does the new reliable transport built on top of UDP fare in different scenarios? Support for unreliable delivery in QUIC remains largely unexplored. The option for delivering content unreliably, as in a best-effort model, deserves the QUIC designers' and community's attention. We propose extending QUIC to support unreliable streams and present a simple approach for implementation. We discuss a simple use case of video streaming---an application that dominates the overall Internet traffic---that can leverage the unreliable streams and potentially bring immense benefits to network operators and content providers. To this end, we present a prototype implementation that, by using both the reliable and unreliable streams in QUIC, outperforms both TCP and QUIC in our evaluations.Comment: Published to ACM CoNEXT Workshop on the Evolution, Performance, and Interoperability of QUIC (EPIQ

    Промышленная безопасность как компонент хозяйственной политики предприятий нефтегазового комплекса: оценка состояния и перспективы развития

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    Исследование инструментов встраивания политики промышленной безопасности компании в общекорпоративную политику. Разработка схемы реализации политики промышленной безопасности через призму функций менеджмента, в которой определены показатели, отражающие промышленную безопасность в каждой функции управления.Investigation of the instruments of embedding the industrial safety policy into corporate policy. Development of a scheme for implementing industrial safety policies through the prism of management functions, which defines indicators that reflect industrial safety in each management function

    FeMn with Phases of a Degradable Ag Alloy for Residue-Free and Adapted Bioresorbability

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    The development of bioresorbable materials for temporary implantation enables progress in medical technology. Iron (Fe)-based degradable materials are biocompatible and exhibit good mechanical properties, but their degradation rate is low. Aside from alloying with Manganese (Mn), the creation of phases with high electrochemical potential such as silver (Ag) phases to cause the anodic dissolution of FeMn is promising. However, to enable residue-free dissolution, the Ag needs to be modified. This concern is addressed, as FeMn modified with a degradable Ag-Calcium-Lanthanum (AgCaLa) alloy is investigated. The electrochemical properties and the degradation behavior are determined via a static immersion test. The local differences in electrochemical potential increase the degradation rate (low pH values), and the formation of gaps around the Ag phases (neutral pH values) demonstrates the benefit of the strategy. Nevertheless, the formation of corrosion-inhibiting layers avoids an increased degradation rate under a neutral pH value. The complete bioresorption of the material is possible since the phases of the degradable AgCaLa alloy dissolve after the FeMn matrix. Cell viability tests reveal biocompatibility, and the antibacterial activity of the degradation supernatant is observed. Thus, FeMn modified with degradable AgCaLa phases is promising as a bioresorbable material if corrosion-inhibiting layers can be diminished

    Qualitätssicherung dezentraler Ölmühlen - Umsetzung eines Qualitätssicherungssystems bei der Produktion, Herstellung und Anwendung von Rapsölkraftstoff

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    In zwei sächsischen Betrieben, die selbst erzeugte Rapssaat in einer Pflanzenölmühle zu Rapspresskuchen und Rapsöl verarbeiten, wurde ein Qualitätssicherungssystem (QSS) für Ölsaaten verarbeitende Betriebe in Sachsen erarbeitet. Der in den beiden Betrieben erzeugte Rapsölkraftstoff zeigt eine für dezentrale Anlagen gleichbleibend hohe Qualität. Die Betriebe zeichnen sich durch ein spezielles Reinigungsverfahren und eine umfassende Qualitätssicherung aus. Das bereits vorhandene QSS des Technologie- und Förderzentrums Straubing (TFZ) bildete die Grundlage für die Entwicklung des universell anwendbaren QSS. Es wurde um Fragen zum Anbau, Einsatz des Rapsölkraftstoffs, Umrüstung der Fahrzeuge, Wartung der Fahrzeuge inkl. BHKW und Einsatz des Presskuchens in der Tierfütterung erweitert und in den beiden Betrieben erprobt. Das entwickelte QSS besteht aus Modulen und ist leicht an die betrieblichen Gegebenheiten vor Ort anzupassen. Das QSS inklusive Handbuch und Kalkulationsmodul zur Berechnung der Wirtschaftlichkeit aller Stufen der Verwertungskette steht im Internet unter http://www.landwirtschaft.sachsen.de/landwirtschaft/7211.htm zur Verfügung

    Qualitätssicherung dezentraler Ölmühlen - Umsetzung eines Qualitätssicherungssystems bei der Produktion, Herstellung und Anwendung von Rapsölkraftstoff

    Get PDF
    In zwei sächsischen Betrieben, die selbst erzeugte Rapssaat in einer Pflanzenölmühle zu Rapspresskuchen und Rapsöl verarbeiten, wurde ein Qualitätssicherungssystem (QSS) für Ölsaaten verarbeitende Betriebe in Sachsen erarbeitet. Der in den beiden Betrieben erzeugte Rapsölkraftstoff zeigt eine für dezentrale Anlagen gleichbleibend hohe Qualität. Die Betriebe zeichnen sich durch ein spezielles Reinigungsverfahren und eine umfassende Qualitätssicherung aus. Das bereits vorhandene QSS des Technologie- und Förderzentrums Straubing (TFZ) bildete die Grundlage für die Entwicklung des universell anwendbaren QSS. Es wurde um Fragen zum Anbau, Einsatz des Rapsölkraftstoffs, Umrüstung der Fahrzeuge, Wartung der Fahrzeuge inkl. BHKW und Einsatz des Presskuchens in der Tierfütterung erweitert und in den beiden Betrieben erprobt. Das entwickelte QSS besteht aus Modulen und ist leicht an die betrieblichen Gegebenheiten vor Ort anzupassen. Das QSS inklusive Handbuch und Kalkulationsmodul zur Berechnung der Wirtschaftlichkeit aller Stufen der Verwertungskette steht im Internet unter http://www.landwirtschaft.sachsen.de/landwirtschaft/7211.htm zur Verfügung

    Neurovascular EGFL7 regulates adult neurogenesis in the subventricular zone and thereby affects olfactory perception

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    Adult neural stem cells reside in a specialized niche in the subventricular zone (SVZ). Throughout life they give rise to adult-born neurons in the olfactory bulb (OB), thus contributing to neural plasticity and pattern discrimination. Here, we show that the neurovascular protein EGFL7 is secreted by endothelial cells and neural stem cells (NSCs) of the SVZ to shape the vascular stem-cell niche. Loss of EGFL7 causes an accumulation of activated NSCs, which display enhanced activity and re-entry into the cell cycle. EGFL7 pushes activated NSCs towards quiescence and neuronal progeny towards differentiation. This is achieved by promoting Dll4-induced Notch signalling at the blood vessel-stem cell interface. Fewer inhibitory neurons form in the OB of EGFL7-knockout mice, which increases the absolute signal conducted from the mitral cell layer of the OB but decreases neuronal network synchronicity. Consequently, EGFL7-knockout mice display severe physiological defects in olfactory behaviour and perception

    Mutant IDH1 Differently Affects Redox State and Metabolism in Glial Cells of Normal and Tumor Origin

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    IDH1R132H (isocitrate dehydrogenase 1) mutations play a key role in the development of low-grade gliomas. IDH1wt converts isocitrate to α-ketoglutarate while reducing nicotinamide adenine dinucleotide phosphate (NADP+), whereas IDH1R132H uses α-ketoglutarate and NADPH to generate the oncometabolite 2-hydroxyglutarate (2-HG). While the effects of 2-HG have been the subject of intense research, the 2-HG independent effects of IDH1R132H are still ambiguous. The present study demonstrates that IDH1R132H expression but not 2-HG alone leads to significantly decreased tricarboxylic acid (TCA) cycle metabolites, reduced proliferation, and enhanced sensitivity to irradiation in both glioblastoma cells and astrocytes in vitro. Glioblastoma cells, but not astrocytes, showed decreased NADPH and NAD+ levels upon IDH1R132H transduction. However, in astrocytes IDH1R132H led to elevated expression of the NAD-synthesizing enzyme nicotinamide phosphoribosyltransferase (NAMPT). These effects were not 2-HG mediated. This suggests that IDH1R132H cells utilize NAD+ to restore NADP pools, which only astrocytes could compensate via induction of NAMPT. We found that the expression of NAMPT is lower in patient-derived IDH1-mutant glioma cells and xenografts compared to IDH1-wildtype models. The Cancer Genome Atlas (TCGA) data analysis confirmed lower NAMPT expression in IDH1-mutant versus IDH1-wildtype gliomas. We show that the IDH1 mutation directly affects the energy homeostasis and redox state in a cell-type dependent manner. Targeting the impairments in metabolism and redox state might open up new avenues for treating IDH1-mutant gliomas.publishedVersio

    Structural Bootstrapping - A Novel, Generative Mechanism for Faster and More Efficient Acquisition of Action-Knowledge

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    eISSN: 1943-0612Humans, but also robots, learn to improve their behavior. Without existing knowledge, learning either needs to be explorative and, thus, slow or-to be more efficient-it needs to rely on supervision, which may not always be available. However, once some knowledge base exists an agent can make use of it to improve learning efficiency and speed. This happens for our children at the age of around three when they very quickly begin to assimilate new information by making guided guesses how this fits to their prior knowledge. This is a very efficient generative learning mechanism in the sense that the existing knowledge is generalized into as-yet unexplored, novel domains. So far generative learning has not been employed for robots and robot learning remains to be a slow and tedious process. The goal of the current study is to devise for the first time a general framework for a generative process that will improve learning and which can be applied at all different levels of the robot's cognitive architecture. To this end, we introduce the concept of structural bootstrapping-borrowed and modified from child language acquisition-to define a probabilistic process that uses existing knowledge together with new observations to supplement our robot's data-base with missing information about planning-, object-, as well as, action-relevant entities. In a kitchen scenario, we use the example of making batter by pouring and mixing two components and show that the agent can efficiently acquire new knowledge about planning operators, objects as well as required motor pattern for stirring by structural bootstrapping. Some benchmarks are shown, too, that demonstrate how structural bootstrapping improves performanceTaikomosios informatikos katedraVytauto Didžiojo universiteta
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