191 research outputs found

    Molecular Clouds as the Origin of the Fermi Gamma-Ray GeV-Excess

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    The so-called "GeV-excess" of the diffuse Galactic gamma-ray emission is studied with a spectral template fit based on energy spectra. The spectral templates can be obtained in a data-driven way from the gamma-ray data, which avoids the use of emissivity models to subtract the standardbackground processes from the data. Instead, one can determine these backgrounds simultaneously with any "signals" in any sky direction, including the Galactic disk and the Galactic center. Using the spectral template fit two hypothesis of the "GeV-excess" were tested: the dark matter (DM) hypothesis assuming the excess is caused by DM annihilation and the molecular cloud (MC) hypothesis assuming the "GeV-excess" is related to a depletion of gamma-rays below 2 GeV, as is directly observed in the Central Molecular Zone (CMZ). Both hypotheses provide acceptable fits, if one considers a limited field-of-view centered within 20^\circ around the Galactic center and applies cuts on the energy range and/or excludes low latitudes, cuts typically applied by the proponents of the DM hypothesis. However, if one considers the whole gamma-ray sky and includes gamma-ray energies up to 100 GeV we find that the MC hypothesis is preferred over the DM hypothesis for several reasons: i) The MC hypothesis provides significantly better fits; ii) The morphology of the "GeV-excess" follows the morphology of the CO-maps, a tracer of MCs, i.e. there exists a strong "GeV-excess" in the Galactic disk also at large longitudes; iii) The massive CMZ with a rectangular field-of-view of l×b=3.5×0.5l \times b = 3.5^{\circ} \times 0.5^{\circ} shows the maximum of the energy flux per log bin in the diffuse gamma-ray spectrum at 2 GeV, i.e. the "GeV-excess", already in the raw data without any analysis. The rectangular profile contradicts the spherical morphology expected for DM annihilation.Comment: 53 pages, 8 figures (+ 42 figures in Appendices), extended version of arXiv:1610.08926 accepted for publication in PR

    Dynamic Priority Rules for Combining On-Demand Passenger Transportation and Transportation of Goods

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    Urban on-demand transportation services are booming, in both passenger transportation and the transportation of goods. The types of service differ in timeliness and compensation and, until now, providers operate larger fleets separately for each type of service. While this may ensure sufficient resources for lucrative passenger transportation, the separation also leaves consolidation potentials untapped. In this paper, we propose combining both services in an anticipatory way that ensures high passenger service rates while simultaneously transporting a large number of goods. To this end, we introduce a dynamic priority policy that uses a time-dependent percentage of vehicles mainly to serve passengers. To find effective time-dependent parametrizations given a limited number of runtime-expensive simulations, we apply Bayesian Optimization. We show that our anticipatory policy increases revenue and service rates significantly while a myopic combination of service may actually lead to inferior performance compared to using two separate fleets

    European Metrology Network (EMN) for Advanced Manufacturing ─ Development of the Strategic Research Agenda (SRA)

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    The European Commission has identified Advanced Manufacturing and Advanced Materials as two of six Key Enabling Technologies (KETs). It is considered that Metrology is a key enabler for the advancement of these KETs. Consequently, EURAMET, the association of metrology institutes in Europe, has strengthened the role of Metrology for these KETs by enabling the creation of a European Metrology Network (EMN) for Advanced Manufacturing. The EMN is comprised of National Metrology Institutes (NMIs) and Designated Institutes (DIs) from across Europe and was formally established in October 2021. The aim of the EMN is to provide a high-level coordination of European metrology activities for the Advanced Manufacturing community. The EMN itself is organized in three sections representing the major stages of the manufacturing chain: 1) Advanced Materials, 2) Smart Manufacturing Systems, and 3) Manufactured Components & Products. The EMN for Advanced Manufacturing is engaging with stakeholders in the field of Advanced Manufacturing (large companies & SMEs, industry organisations, existing networks, and academia), as well as the wider Metrology community, including Technical Committees, to provide input for the Strategic Research Agenda (SRA) on Metrology for Advanced Manufacturing. This contribution will give an overview about the first version of the SRA prepared by the EMN for Advanced Manufacturing

    Progress of the European Metrology Network for Advanced Manufacturing

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    The European Metrology Network (EMN) for Advanced Manufacturing has been established in June 2021. Currently nine EMNs focussing on different important topics of strategic importance for Europe exist and form an integral part of EURAMET, the European Association of National Metrology Institutes (NMI). All EMNs are tasked to develop a high-level coordination of the metrology community in Europe in a close dialogue with the respective stakeholders. The development of a Strategic Research Agenda (SRA) is a key task for all EMNs in their thematic areas as important input for the European Partnership on Metrology programme in alignment with other relevant European Partnerships. This task will be based on an analysis of the existing metrology infrastructure and capabilities of the NMIs, the metrology research needs for advanced manufacturing identified in close cooperation with industrial stakeholders and a resulting gap analysis. Here we report on the progress of the EMN for Advanced Manufacturing

    AdvManuNet: a networking project on metrology for advanced manufacturing

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    The networking project AdvManuNet has been started recently to accelerate the process of establishing an European Metrology Network (EMN) on Advanced Manufacturing. EMNs are intended by EURAMET, the association of metrology institutes in Europe, to provide a sustainable structure for ongoing stakeholder interaction in different thematic areas. Advanced manufacturing has been identified by the European Commission (EC) as one of six Key Enabling Technologies (KETs) with applications in multiple industries. Various EURAMET projects have partly addressed metrology needs for advanced manufacturing. However, a high-level coordination of the metrology community is currently absent and limits the impact of metrology developments on advanced manufacturing. AdvManuNet will address these limits by establishing a single hub for stakeholder consultation, a knowledge base on research results, and a strategic agenda for research and training to push forward advanced manufacturing and related KETs and strengthen Europe’s position in advanced manufacturing via the EMN

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    The Dynamics of the Neuropeptide Y Receptor Type 1 Investigated by Solid-State NMR and Molecular Dynamics Simulation

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    We report data on the structural dynamics of the neuropeptide Y (NPY) G-protein-coupled receptor (GPCR) type 1 (Y1R), a typical representative of class A peptide ligand GPCRs, using a combination of solid-state NMR and molecular dynamics (MD) simulation. First, the equilibrium dynamics of Y1R were studied using 15N-NMR and quantitative determination of 1H-13C order parameters through the measurement of dipolar couplings in separated-local-field NMR experiments. Order parameters reporting the amplitudes of the molecular motions of the C-H bond vectors of Y1R in DMPC membranes are 0.57 for the Cα sites and lower in the side chains (0.37 for the CH2 and 0.18 for the CH3 groups). Different NMR excitation schemes identify relatively rigid and also dynamic segments of the molecule. In monounsaturated membranes composed of longer lipid chains, Y1R is more rigid, attributed to a higher hydrophobic thickness of the lipid membrane. The presence of an antagonist or NPY has little influence on the amplitude of motions, whereas the addition of agonist and arrestin led to a pronounced rigidization. To investigate Y1R dynamics with site resolution, we conducted extensive all-atom MD simulations of the apo and antagonist-bound state. In each state, three replicas with a length of 20 μs (with one exception, where the trajectory length was 10 μs) were conducted. In these simulations, order parameters of each residue were determined and showed high values in the transmembrane helices, whereas the loops and termini exhibit much lower order. The extracellular helix segments undergo larger amplitude motions than their intracellular counterparts, whereas the opposite is observed for the loops, Helix 8, and termini. Only minor differences in order were observed between the apo and antagonist-bound state, whereas the time scale of the motions is shorter for the apo state. Although these relatively fast motions occurring with correlation times of ns up to a few µs have no direct relevance for receptor activation, it is believed that they represent the prerequisite for larger conformational transitions in proteins

    New European Metrology Network for advanced manufacturing

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    Advanced manufacturing has been identified as one of the key enabling technologies with applications in multiple industries. The growing importance of advanced manufacturing is reflected by an increased number of publications on this topic in recent years. Advanced manufacturing requires new and enhanced metrology methods to assure the quality of manufacturing processes and the resulting products. However, a high-level coordination of the metrology community is currently absent in this field and consequently this limits the impact of metrology developments on advanced manufacturing. In this article we introduce the new European Metrology Network (EMN) for Advanced Manufacturing within EURAMET, the European Association of National Metrology Institutes (NMIs). The EMN is intended to be operated sustainably by NMIs and Designated Institutes in close cooperation with stakeholders interested in advanced manufacturing. The objectives of the EMN are to set up a permanent stakeholder dialogue, to develop a Strategic Research Agenda for the metrology input required for advanced manufacturing technologies, to create and maintain a knowledge sharing programme and to implement a web-based service desk for stakeholders. The EMN development is supported by a Joint Network Project within the European Metrology Programme for Innovation and Research

    QUEnch assiSTed (QUEST) MRI Used as a Novel Approach to Identify Reactive Oxygen Species as a Result of Experimental TBI

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    Introduction: Traumatic brain injury (TBI) generates reactive oxygen species (ROS), promoting inflammatory processes and impeding TBI recovery. Within the VA population, over 70% of military personnel that sustain a TBI receive opioid-based pain relief, however, opiates may actually exacerbate post-TBI complications through its documented recruitment of oxidative and inflammatory systems. Thus, we hypothesize that TBI and opioid treatment act synergistically to worsen post-TBI oxidative stress. Methods: Mice were exposed to either TBI or sham injury and administered morphine or saline in the acute post-injury period. Afterwards, neuroimaging was conducted using a novel technique, QUEnch assiSTed (QUEST) MRI, which compares standard MRI signals across mice that acutely receive an antioxidant “quench” therapy and those receiving saline as control. Therefore, differential MRI signals between these groups are an index of ROS generation. Changes in hippocampus and cortex signals were measured, as these structures are most commonly affected by TBI. Methylene blue and α-lipoic acid were used as antioxidants in the quenching step as they halt mitochondrial ROS production and scavenge excess ROS, respectively. Results: No significant changes in ROS levels were detected as a result of TBI, opioid exposure or their combination using QUEST MRI in either the cortex or hippocampus. Conclusions and Future Directions: While QUEST imaging did not yield significant changes between experimental groups, future work will include ex-vivo biochemical ROS analyses from harvested tissues, which will provide higher resolution quantification of oxidative processes than that of QUEST MRI
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