| 1. |
- Aad, G., et al.
(author)
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- 2013
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swepub:Mat__t (peer-reviewed)
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| 2. |
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- 2017
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In: Physical Review D. - 2470-0010 .- 2470-0029. ; 96:2
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Journal article (peer-reviewed)
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| 3. |
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| 4. |
- Aartsen, M. G., et al.
(author)
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Multiwavelength follow-up of a rare IceCube neutrino multiplet
- 2017
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In: Astronomy and Astrophysics. - : EDP SCIENCES S A. - 0004-6361 .- 1432-0746. ; 607
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Journal article (peer-reviewed)abstract
- On February 17, 2016, the IceCube real-time neutrino search identified, for the first time, three muon neutrino candidates arriving within 100 s of one another, consistent with coming from the same point in the sky. Such a triplet is expected once every 13.7 years as a random coincidence of background events. However, considering the lifetime of the follow-up program the probability of detecting at least one triplet from atmospheric background is 32%. Follow-up observatories were notified in order to search for an electromagnetic counterpart. Observations were obtained by Swift's X-ray telescope, by ASAS-SN, LCO and MASTER at optical wavelengths, and by VERITAS in the very-high-energy gamma-ray regime. Moreover, the Swift BAT serendipitously observed the location 100 s after the first neutrino was detected, and data from the Fermi LAT and HAWC observatory were analyzed. We present details of the neutrino triplet and the follow-up observations. No likely electromagnetic counterpart was detected, and we discuss the implications of these constraints on candidate neutrino sources such as gamma-ray bursts, core-collapse supernovae and active galactic nucleus flares. This study illustrates the potential of and challenges for future follow-up campaigns.
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| 5. |
- Maksimovic, M., et al.
(author)
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First observations and performance of the RPW instrument on board the Solar Orbiter mission
- 2021
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In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 656
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Journal article (peer-reviewed)abstract
- The Radio and Plasma Waves (RPW) instrument on the ESA Solar Orbiter mission is designed to measure in situ magnetic and electric fields and waves from the continuum up to several hundred kHz. The RPW also observes solar and heliospheric radio emissions up to 16 MHz. It was switched on and its antennae were successfully deployed two days after the launch of Solar Orbiter on February 10, 2020. Since then, the instrument has acquired enough data to make it possible to assess its performance and the electromagnetic disturbances it experiences. In this article, we assess its scientific performance and present the first RPW observations. In particular, we focus on a statistical analysis of the first observations of interplanetary dust by the instrument's Thermal Noise Receiver. We also review the electro-magnetic disturbances that RPW suffers, especially those which potential users of the instrument data should be aware of before starting their research work.
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| 6. |
- Maksimovic, M., et al.
(author)
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The Solar Orbiter Radio and Plasma Waves (RPW) instrument
- 2020
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In: Astronomy and Astrophysics. - : EDP SCIENCES S A. - 0004-6361 .- 1432-0746. ; 642
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Journal article (peer-reviewed)abstract
- The Radio and Plasma Waves (RPW) instrument on the ESA Solar Orbiter mission is described in this paper. This instrument is designed to measure in-situ magnetic and electric fields and waves from the continuous to a few hundreds of kHz. RPW will also observe solar radio emissions up to 16 MHz. The RPW instrument is of primary importance to the Solar Orbiter mission and science requirements since it is essential to answer three of the four mission overarching science objectives. In addition RPW will exchange on-board data with the other in-situ instruments in order to process algorithms for interplanetary shocks and type III langmuir waves detections.
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| 7. |
- Aartsen, M. G., et al.
(author)
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Very high-energy gamma-ray follow-up program using neutrino triggers from IceCube
- 2016
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In: Journal of Instrumentation. - 1748-0221. ; 11
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Journal article (peer-reviewed)abstract
- We describe and report the status of a neutrino-triggered program in IceCube that generates real-time alerts for gamma-ray follow-up observations by atmospheric-Cherenkov telescopes (MAGIC and VERITAS). While IceCube is capable of monitoring the whole sky continuously, high-energy gamma-ray telescopes have restricted fields of view and in general are unlikely to be observing a potential neutrino-flaring source at the time such neutrinos are recorded. The use of neutrino-triggered alerts thus aims at increasing the availability of simultaneous multi-messenger data during potential neutrino flaring activity, which can increase the discovery potential and constrain the phenomenological interpretation of the high-energy emission of selected source classes (e. g. blazars). The requirements of a fast and stable online analysis of potential neutrino signals and its operation are presented, along with first results of the program operating between 14 March 2012 and 31 December 2015.
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| 8. |
- Abbasi, R., et al.
(author)
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Acceptance Tests of more than 10 000 Photomultiplier Tubes for the multi-PMT Digital Optical Modules of the IceCube Upgrade
- 2024
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In: Journal of Instrumentation. - 1748-0221. ; 19:7
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Journal article (peer-reviewed)abstract
- More than 10 000 photomultiplier tubes (PMTs) with a diameter of 80 mm will be installed in multi-PMT Digital Optical Modules (mDOMs) of the IceCube Upgrade. These have been tested and pre-calibrated at two sites. A throughput of more than 1000 PMTs per week with both sites was achieved with a modular design of the testing facilities and highly automated testing procedures. The testing facilities can easily be adapted to other PMTs, such that they can, e.g., be re-used for testing the PMTs for IceCube-Gen2. Single photoelectron response, high voltage dependence, time resolution, prepulse, late pulse, afterpulse probabilities, and dark rates were measured for each PMT. We describe the design of the testing facilities, the testing procedures, and the results of the acceptance tests.
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| 9. |
- Abbasi, R., et al.
(author)
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Characterization of the astrophysical diffuse neutrino flux using starting track events in IceCube
- 2024
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In: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 2470-0010 .- 2470-0029. ; 110:2
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Journal article (peer-reviewed)abstract
- A measurement of the diffuse astrophysical neutrino spectrum is presented using IceCube data collected from 2011-2022 (10.3 years). We developed novel detection techniques to search for events with a contained vertex and exiting track induced by muon neutrinos undergoing a charged-current interaction. Searching for these starting track events allows us to not only more effectively reject atmospheric muons but also atmospheric neutrino backgrounds in the southern sky, opening a new window to the sub-100 TeV astrophysical neutrino sky. The event selection is constructed using a dynamic starting track veto and machine learning algorithms. We use this data to measure the astrophysical diffuse flux as a single power law flux (SPL) with a best-fit spectral index of γ=2.58-0.09+0.10 and per-flavor normalization of φper-flavorAstro=1.68-0.22+0.19×10-18×GeV-1 cm-2 s-1 sr-1 (at 100 TeV). The sensitive energy range for this dataset is 3-550 TeV under the SPL assumption. This data was also used to measure the flux under a broken power law, however we did not find any evidence of a low energy cutoff.
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| 10. |
- Abbasi, R., et al.
(author)
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Citizen science for IceCube: Name that Neutrino
- 2024
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In: European Physical Journal Plus. - 2190-5444. ; 139:6
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Journal article (peer-reviewed)abstract
- Name that Neutrino is a citizen science project where volunteers aid in classification of events for the IceCube Neutrino Observatory, an immense particle detector at the geographic South Pole. From March 2023 to September 2023, volunteers did classifications of videos produced from simulated data of both neutrino signal and background interactions. Name that Neutrino obtained more than 128,000 classifications by over 1800 registered volunteers that were compared to results obtained by a deep neural network machine-learning algorithm. Possible improvements for both Name that Neutrino and the deep neural network are discussed.
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| 11. |
- Abbasi, R., et al.
(author)
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Improved modeling of in-ice particle showers for IceCube event reconstruction
- 2024
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In: Journal of Instrumentation. - 1748-0221. ; 19:6
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Journal article (peer-reviewed)abstract
- The IceCube Neutrino Observatory relies on an array of photomultiplier tubes to detect Cherenkov light produced by charged particles in the South Pole ice. IceCube data analyses depend on an in-depth characterization of the glacial ice, and on novel approaches in event reconstruction that utilize fast approximations of photoelectron yields. Here, a more accurate model is derived for event reconstruction that better captures our current knowledge of ice optical properties. When evaluated on a Monte Carlo simulation set, the median angular resolution for in-ice particle showers improves by over a factor of three compared to a reconstruction based on a simplified model of the ice. The most substantial improvement is obtained when including effects of birefringence due to the polycrystalline structure of the ice. When evaluated on data classified as particle showers in the high-energy starting events sample, a significantly improved description of the events is observed.
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| 12. |
- Abbasi, R., et al.
(author)
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Measurement of atmospheric neutrino mixing with improved IceCube DeepCore calibration and data processing
- 2023
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In: Physical Review D. - 2470-0010 .- 2470-0029. ; 108:1
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Journal article (peer-reviewed)abstract
- We describe a new data sample of IceCube DeepCore and report on the latest measurement of atmospheric neutrino oscillations obtained with data recorded between 2011-2019. The sample includes significant improvements in data calibration, detector simulation, and data processing, and the analysis benefits from a sophisticated treatment of systematic uncertainties, with significantly greater level of detail since our last study. By measuring the relative fluxes of neutrino flavors as a function of their reconstructed energies and arrival directions we constrain the atmospheric neutrino mixing parameters to be sin2θ23=0.51±0.05 and Δm322=2.41±0.07×10-3 eV2, assuming a normal mass ordering. The errors include both statistical and systematic uncertainties. The resulting 40% reduction in the error of both parameters with respect to our previous result makes this the most precise measurement of oscillation parameters using atmospheric neutrinos. Our results are also compatible and complementary to those obtained using neutrino beams from accelerators, which are obtained at lower neutrino energies and are subject to different sources of uncertainties.
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| 13. |
- Abbasi, R., et al.
(author)
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Search for decoherence from quantum gravity with atmospheric neutrinos
- 2024
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In: Nature Physics. - 1745-2481 .- 1745-2473. ; 20:6, s. 913-920
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Journal article (peer-reviewed)abstract
- Neutrino oscillations at the highest energies and longest baselines can be used to study the structure of spacetime and test the fundamental principles of quantum mechanics. If the metric of spacetime has a quantum mechanical description, its fluctuations at the Planck scale are expected to introduce non-unitary effects that are inconsistent with the standard unitary time evolution of quantum mechanics. Neutrinos interacting with such fluctuations would lose their quantum coherence, deviating from the expected oscillatory flavour composition at long distances and high energies. Here we use atmospheric neutrinos detected by the IceCube South Pole Neutrino Observatory in the energy range of 0.5-10.0 TeV to search for coherence loss in neutrino propagation. We find no evidence of anomalous neutrino decoherence and determine limits on neutrino-quantum gravity interactions. The constraint on the effective decoherence strength parameter within an energy-independent decoherence model improves on previous limits by a factor of 30. For decoherence effects scaling as E2, our limits are advanced by more than six orders of magnitude beyond past measurements compared with the state of the art. Interactions of atmospheric neutrinos with quantum-gravity-induced fluctuations of the metric of spacetime would lead to decoherence. The IceCube Collaboration constrains such interactions with atmospheric neutrinos.
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| 14. |
- Ahrens, J., et al.
(author)
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Muon track reconstruction and data selection techniques in AMANDA
- 2004
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In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 524:1-3, s. 169-194
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Journal article (peer-reviewed)abstract
- The Antarctic Muon And Neutrino Detector Array (AMANDA) is a high-energy neutrino telescope operating at the geographic South Pole. It is a lattice of photo-multiplier tubes buried deep in the polar ice between 1500 and 2000 m. The primary goal of this detector is to discover astrophysical sources of high-energy neutrinos. A high-energy muon neutrino coming through the earth from the Northern Hemisphere can be identified by the secondary muon moving upward through the detector. The muon tracks are reconstructed with a maximum likelihood method. It models the arrival times and amplitudes of Cherenkov photons registered by the photo-multipliers. This paper describes the different methods of reconstruction, which have been successfully implemented within AMANDA. Strategies for optimizing the reconstruction performance and rejecting background are presented. For a typical analysis procedure the direction of tracks are reconstructed with about 2° accuracy. © 2004 Elsevier B.V. All rights reserved.
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| 15. |
- Ahrens, J., et al.
(author)
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Search for Extraterrestrial Point Sources of Neutrinos with AMANDA-II
- 2004
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In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 92:7, s. 711021-711025
-
Journal article (peer-reviewed)abstract
- The results of a search for point sources of high energy neutrinos in the northern hemisphere were presented using AMANDA-II data collected in the year 2000. The results included the flux limits on several active-galactic-nuclei blazars, microquasars, magnetars, and other candidate neutrino sources. A search for excesses above a random background of cosmic ray induced atmospheric neutrinos and misreconstructed downgoing cosmic-rays muons, which revealed no statistically significant neutrino point sources was also presented. It was shown that AMANDA-II had achieved the sensitivity required to probe known TeV γ-ray sources such as the blazar Markarian 501 in its 1997 flaring state at a level where neutrino and γ-ray fluxes were equal.
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| 16. |
- Niessen, Peter, et al.
(author)
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Recent results from the amanda experiment
- 2003
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In: Proceedings of 38th Rencontres de Moriond on Electroweak Interactions and Unified Theories 15-22 Mar 2003. Les Arcs, France.
-
Conference paper (peer-reviewed)abstract
- AMANDA (Antarctic Muon And Neutrino Detector Array) is a neutrino telescope built under the southern polar icecap and its scope is to explore the possibility to detect high energy cosmic neutrinos. This should generate insight into the powerful celestial objects where acceleration mechanisms can bring up to 10 20 eV. We describe the achievements and results from the AMANDA-B10 prototype and the preliminary results from the current AMANDA-II detector which show dramatic increase in sensitivity.
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| 17. |
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| 18. |
- Aartsen, M. G., et al.
(author)
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Constraints on Ultrahigh-Energy Cosmic-Ray Sources from a Search for Neutrinos above 10 PeV with IceCube
- 2016
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In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 117:24
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Journal article (peer-reviewed)abstract
- We report constraints on the sources of ultrahigh-energy cosmic rays (UHECRs) above 10(9) GeV, based on an analysis of seven years of IceCube data. This analysis efficiently selects very high-energy neutrino-induced events which have deposited energies from 5 x 10(5) GeV to above 10(11) GeV. Two neutrino-induced events with an estimated deposited energy of (2.6 +/- 0.3) x 10(6) GeV, the highest neutrino energy observed so far, and (7.7 +/- 2.0) x 10(5) GeV were detected. The atmospheric background-only hypothesis of detecting these events is rejected at 3.6 sigma. The hypothesis that the observed events are of cosmogenic origin is also rejected at > 99% CL because of the limited deposited energy and the nonobservation of events at higher energy, while their observation is consistent with an astrophysical origin. Our limits on cosmogenic neutrino fluxes disfavor the UHECR sources having a cosmological evolution stronger than the star formation rate, e.g., active galactic nuclei and gamma-ray bursts, assuming proton-dominated UHECRs. Constraints on UHECR sources including mixed and heavy UHECR compositions are obtained for models of neutrino production within UHECR sources. Our limit disfavors a significant part of parameter space for active galactic nuclei and new-born pulsar models. These limits on the ultrahigh-energy neutrino flux models are the most stringent to date.
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| 19. |
- Abbasi, R., et al.
(author)
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Search for 10-1000 GeV Neutrinos from Gamma-Ray Bursts with IceCube
- 2024
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In: Astrophysical Journal. - : Institute of Physics (IOP). - 1538-4357 .- 0004-637X. ; 964:2
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Journal article (peer-reviewed)abstract
- We present the results of a search for 10-1000 GeV neutrinos from 2268 gamma-ray bursts (GRBs) over 8 yr of IceCube-DeepCore data. This work probes burst physics below the photosphere where electromagnetic radiation cannot escape. Neutrinos of tens of giga electronvolts are predicted in sub-photospheric collision of free-streaming neutrons with bulk-jet protons. In a first analysis, we searched for the most significant neutrino-GRB coincidence using six overlapping time windows centered on the prompt phase of each GRB. In a second analysis, we conducted a search for a group of GRBs, each individually too weak to be detectable, but potentially significant when combined. No evidence of neutrino emission is found for either analysis. The most significant neutrino coincidence is for Fermi-GBM GRB bn 140807500, with a p-value of 0.097 corrected for all trials. The binomial test used to search for a group of GRBs had a p-value of 0.65 after all trial corrections. The binomial test found a group consisting only of GRB bn 140807500 and no additional GRBs. The neutrino limits of this work complement those obtained by IceCube at tera electronvolt to peta electronvolt energies. We compare our findings for the large set of GRBs as well as GRB 221009A to the sub-photospheric neutron-proton collision model and find that GRB 221009A provides the most constraining limit on baryon loading. For a jet Lorentz factor of 300 (800), the baryon loading on GRB 221009A is lower than 3.85 (2.13) at a 90% confidence level.
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| 20. |
- Abbasi, R., et al.
(author)
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Search for Continuous and Transient Neutrino Emission Associated with IceCube's Highest-energy Tracks: An 11 yr Analysis
- 2024
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In: Astrophysical Journal. - : Institute of Physics (IOP). - 1538-4357 .- 0004-637X. ; 964:1
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Journal article (peer-reviewed)abstract
- IceCube alert events are neutrinos with a moderate-to-high probability of having astrophysical origin. In this study, we analyze 11 yr of IceCube data and investigate 122 alert events and a selection of high-energy tracks detected between 2009 and the end of 2021. This high-energy event selection (alert events + high-energy tracks) has an average probability of >= 0.5 of being of astrophysical origin. We search for additional continuous and transient neutrino emission within the high-energy events' error regions. We find no evidence for significant continuous neutrino emission from any of the alert event directions. The only locally significant neutrino emission is the transient emission associated with the blazar TXS 0506+056, with a local significance of 3 sigma, which confirms previous IceCube studies. When correcting for 122 test positions, the global p-value is 0.156 and compatible with the background hypothesis. We constrain the total continuous flux emitted from all 122 test positions at 100 TeV to be below 1.2 x 10-15 (TeV cm2 s)-1 at 90% confidence assuming an E -2 spectrum. This corresponds to 4.5% of IceCube's astrophysical diffuse flux. Overall, we find no indication that alert events in general are linked to lower-energetic continuous or transient neutrino emission.
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| 21. |
- Abbasi, R., et al.
(author)
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Search for Galactic Core-collapse Supernovae in a Decade of Data Taken with the IceCube Neutrino Observatory
- 2024
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In: Astrophysical Journal. - : Institute of Physics Publishing (IOPP). - 1538-4357 .- 0004-637X. ; 961:1
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Journal article (peer-reviewed)abstract
- The IceCube Neutrino Observatory has been continuously taking data to search for O(0.5–10) s long neutrino bursts since 2007. Even if a Galactic core-collapse supernova is optically obscured or collapses to a black hole instead of exploding, it will be detectable via the O(10) MeV neutrino burst emitted during the collapse. We discuss a search for such events covering the time between 2008 April 17 and 2019 December 31. Considering the average data taking and analysis uptime of 91.7% after all selection cuts, this is equivalent to 10.735 yr of continuous data taking. In order to test the most conservative neutrino production scenario, the selection cuts were optimized for a model based on an 8.8 solar mass progenitor collapsing to an O–Ne–Mg core. Conservative assumptions on the effects of neutrino oscillations in the exploding star were made. The final selection cut was set to ensure that the probability to detect such a supernova within the Milky Way exceeds 99%. No such neutrino burst was found in the data after performing a blind analysis. Hence, a 90% C.L. upper limit on the rate of core-collapse supernovae out to distances of ≈25 kpc was determined to be 0.23 yr−1. For the more distant Magellanic Clouds, only high neutrino luminosity supernovae will be detectable by IceCube, unless external information on the burst time is available. We determined a model-independent limit by parameterizing the dependence on the neutrino luminosity and the energy spectrum.
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| 22. |
- Burisch, J., et al.
(author)
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East-West gradient in the incidence of inflammatory bowel disease in Europe: the ECCO-EpiCom inception cohort
- 2014
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In: Gut. - : BMJ Publishing Group. - 0017-5749 .- 1468-3288. ; 63:4, s. 588-597
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Journal article (peer-reviewed)abstract
- Objective The incidence of inflammatory bowel disease (IBD) is increasing in Eastern Europe. The reasons for these changes remain unknown. The aim of this study was to investigate whether an East–West gradient in the incidence of IBD in Europe exists.Design A prospective, uniformly diagnosed, population based inception cohort of IBD patients in 31 centres from 14 Western and eight Eastern European countries covering a total background population of approximately 10.1 million people was created. One-third of the centres had previous experience with inception cohorts. Patients were entered into a low cost, web based epidemiological database, making participation possible regardless of socioeconomic status and prior experience.Results 1515 patients aged 15 years or older were included, of whom 535 (35%) were diagnosed with Crohn's disease (CD), 813 (54%) with ulcerative colitis (UC) and 167 (11%) with IBD unclassified (IBDU). The overall incidence rate ratios in all Western European centres were 1.9 (95% CI 1.5 to 2.4) for CD and 2.1 (95% CI 1.8 to 2.6) for UC compared with Eastern European centres. The median crude annual incidence rates per 100 000 in 2010 for CD were 6.5 (range 0–10.7) in Western European centres and 3.1 (range 0.4–11.5) in Eastern European centres, for UC 10.8 (range 2.9–31.5) and 4.1 (range 2.4–10.3), respectively, and for IBDU 1.9 (range 0–39.4) and 0 (range 0–1.2), respectively. In Western Europe, 92% of CD, 78% of UC and 74% of IBDU patients had a colonoscopy performed as the diagnostic procedure compared with 90%, 100% and 96%, respectively, in Eastern Europe. 8% of CD and 1% of UC patients in both regions underwent surgery within the first 3 months of the onset of disease. 7% of CD patients and 3% of UC patients from Western Europe received biological treatment as rescue therapy. Of all European CD patients, 20% received only 5-aminosalicylates as induction therapy.Conclusions An East–West gradient in IBD incidence exists in Europe. Among this inception cohort—including indolent and aggressive cases—international guidelines for diagnosis and initial treatment are not being followed uniformly by physicians.
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| 23. |
- Burisch, J, et al.
(author)
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Natural disease course of Crohn's disease during the first 5 years after diagnosis in a European population-based inception cohort: an Epi-IBD study
- 2019
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In: Gut. - : BMJ. - 1468-3288 .- 0017-5749. ; 68:3, s. 423-433
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Journal article (peer-reviewed)abstract
- The Epi-IBD cohort is a prospective population-based inception cohort of unselected patients with inflammatory bowel disease from 29 European centres covering a background population of almost 10 million people. The aim of this study was to assess the 5-year outcome and disease course of patients with Crohn’s disease (CD).DesignPatients were followed up prospectively from the time of diagnosis, including collection of their clinical data, demographics, disease activity, medical therapy, surgery, cancers and deaths. Associations between outcomes and multiple covariates were analysed by Cox regression analysis.ResultsIn total, 488 patients were included in the study. During follow-up, 107 (22%) patients received surgery, while 176 (36%) patients were hospitalised because of CD. A total of 49 (14%) patients diagnosed with non-stricturing, non-penetrating disease progressed to either stricturing and/or penetrating disease. These rates did not differ between patients from Western and Eastern Europe. However, significant geographic differences were noted regarding treatment: more patients in Western Europe received biological therapy (33%) and immunomodulators (66%) than did those in Eastern Europe (14% and 54%, respectively, P<0.01), while more Eastern European patients received 5-aminosalicylates (90% vs 56%, P<0.05). Treatment with immunomodulators reduced the risk of surgery (HR: 0.4, 95% CI 0.2 to 0.6) and hospitalisation (HR: 0.3, 95% CI 0.2 to 0.5).ConclusionDespite patients being treated early and frequently with immunomodulators and biological therapy in Western Europe, 5-year outcomes including surgery and phenotype progression in this cohort were comparable across Western and Eastern Europe. Differences in treatment strategies between Western and Eastern European centres did not affect the disease course. Treatment with immunomodulators reduced the risk of surgery and hospitalisation.
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| 24. |
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| 25. |
- Feldmann, M., et al.
(author)
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Economic and durable design of composite bridges with integral abutments
- 2010
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Reports (peer-reviewed)abstract
- In the design and construction of bridges, questions of sustainability, maintenance and durability are becoming more and more important for European road administrations, in addition to safety and serviceability issues. Therefore integral abutment bridges are becoming highly attractive to designers, constructors and road administrations, as they tend to be less expensive to build, easier to maintain and more economical to own over their life time. Bearings and joints are main sources of maintenance costs during a lifetime. These costs vanish because the bridges are joint- and bearing-free. However, this very advantage complicates the design compared to conventional bridges in some crucial respects. Combined with the fact that most European countries have only limited experience with integral bridges to date, this leads to a reluctance of road administrations to use this bridge type. Thus the main objective of the project is to experimentally and theoretically investigate the behaviour of critical points of integral abutment bridges. Regarding the soil-structure interaction, recommendations are elaborated based on monitoring results as well as previous research and monitoring campaigns. Conventional HP piles and sheet piles are investigated as a foundation. Furthermore a hinged HP connection is developed to decrease the stresses in the pile system. An investigation of the design and construction of the slab to pavement approach is also carried out to avoid major damages to the structure. Finally the most important information is condensed into the essential features in form of a 'Design guide for composite bridges with integral abutments'
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| 26. |
- Sungnak, W., et al.
(author)
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SARS-CoV-2 entry factors are highly expressed in nasal epithelial cells together with innate immune genes
- 2020
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In: Nature Medicine. - : Nature Research. - 1078-8956 .- 1546-170X. ; 26:5, s. 681-687
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Journal article (peer-reviewed)abstract
- We investigated SARS-CoV-2 potential tropism by surveying expression of viral entry-associated genes in single-cell RNA-sequencing data from multiple tissues from healthy human donors. We co-detected these transcripts in specific respiratory, corneal and intestinal epithelial cells, potentially explaining the high efficiency of SARS-CoV-2 transmission. These genes are co-expressed in nasal epithelial cells with genes involved in innate immunity, highlighting the cells’ potential role in initial viral infection, spread and clearance. The study offers a useful resource for further lines of inquiry with valuable clinical samples from COVID-19 patients and we provide our data in a comprehensive, open and user-friendly fashion at www.covid19cellatlas.org.
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| 27. |
- Aartsen, M. G., et al.
(author)
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All-flavour search for neutrinos from dark matter annihilations in the Milky Way with IceCube/DeepCore
- 2016
-
In: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 76:10
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Journal article (peer-reviewed)abstract
- We present the first IceCube search for a signal of dark matter annihilations in the Milky Way using all-flavour neutrino-induced particle cascades. The analysis focuses on the DeepCore sub-detector of IceCube, and uses the surrounding IceCube strings as a veto region in order to select starting events in the DeepCore volume. We use 329 live-days of data from IceCube operating in its 86-string configuration during 2011-2012. No neutrino excess is found, the final result being compatible with the background-only hypothesis. From this null result, we derive upper limits on the velocity-averaged self-annihilation cross-section, , for dark matter candidate masses ranging from 30 GeV up to 10 TeV, assuming both a cuspy and a flat-cored dark matter halo profile. For dark matter masses between 200 GeV and 10 TeV, the results improve on all previous IceCube results on , reaching a level of 10 cm s, depending on the annihilation channel assumed, for a cusped NFW profile. The analysis demonstrates that all-flavour searches are competitive with muon channel searches despite the intrinsically worse angular resolution of cascades compared to muon tracks in IceCube.
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| 28. |
- Aartsen, M. G., et al.
(author)
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Astrophysical neutrinos and cosmic rays observed by IceCube
- 2018
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In: Advances in Space Research. - : Elsevier BV. - 0273-1177 .- 1879-1948. ; 62:10, s. 2902-2930
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Journal article (peer-reviewed)abstract
- The core mission of the IceCube neutrino observatory is to study the origin and propagation of cosmic rays. IceCube, with its surface component IceTop, observes multiple signatures to accomplish this mission. Most important are the astrophysical neutrinos that are produced in interactions of cosmic rays, close to their sources and in interstellar space. IceCube is the first instrument that measures the properties of this astrophysical neutrino flux and constrains its origin. In addition, the spectrum, composition, and anisotropy of the local cosmic-ray flux are obtained from measurements of atmospheric muons and showers. Here we provide an overview of recent findings from the analysis of IceCube data, and their implications to our understanding of cosmic rays.
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| 29. |
- Aartsen, M. G., et al.
(author)
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First search for dark matter annihilations in the Earth with the IceCube detector
- 2017
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In: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 77:2
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Journal article (peer-reviewed)abstract
- We present the results of the first IceCube search for dark matter annihilation in the center of the Earth. Weakly interacting massive particles (WIMPs), candidates for dark matter, can scatter off nuclei inside the Earth and fall below its escape velocity. Over time the captured WIMPs will be accumulated and may eventually self-annihilate. Among the annihilation products only neutrinos can escape from the center of the Earth. Large-scale neutrino telescopes, such as the cubic kilometer IceCube Neutrino Observatory located at the South Pole, can be used to search for such neutrino fluxes. Data from 327 days of detector livetime during 2011/2012 were analyzed. No excess beyond the expected background from atmospheric neutrinos was detected. The derived upper limits on the annihilation rate of WIMPs in the Earth (Gamma(A) = 1.12 x 10(14) s(-1) for WIMP masses of 50 GeV annihilating into tau leptons) and the resulting muon flux are an order of magnitude stronger than the limits of the last analysis performed with data from IceCube's predecessor AMANDA. The limits can be translated in terms of a spin-independent WIMP-nucleon cross section. For a WIMP mass of 50GeV this analysis results in the most restrictive limits achieved with IceCube data.
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| 30. |
- Aartsen, M. G., et al.
(author)
-
Lowering Icecube'S Energy Threshold For Point Source Searches In The Southern Sky
- 2016
-
In: Astrophysical Journal Letters. - 2041-8205 .- 2041-8213. ; 824:2
-
Journal article (peer-reviewed)abstract
- Observation of a point source of astrophysical neutrinos would be a "smoking gun" signature of a cosmic-ray accelerator. While IceCube has recently discovered a diffuse flux of astrophysical neutrinos, no localized point source has been observed. Previous IceCube searches for point sources in the southern sky were restricted by either an energy threshold above a few hundred TeV or poor neutrino angular resolution. Here we present a search for southern sky point sources with greatly improved sensitivities to neutrinos with energies below 100 TeV. By selecting charged-current nu(mu) interacting inside the detector, we reduce the atmospheric background while retaining efficiency for astrophysical neutrino-induced events reconstructed with sub-degree angular resolution. The new event sample covers three years of detector data and leads to a factor of 10 improvement in sensitivity to point sources emitting below 100 TeV in the southern sky. No statistically significant evidence of point sources was found, and upper limits are set on neutrino emission from individual sources. A posteriori analysis of the highest-energy (similar to 100 TeV) starting event in the sample found that this event alone represents a 2.8 sigma deviation from the hypothesis that the data consists only of atmospheric background.
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| 31. |
- Aartsen, M. G., et al.
(author)
-
Measurement of the nu(mu) energy spectrum with IceCube-79
- 2017
-
In: European Physical Journal C. - : SPRINGER. - 1434-6044 .- 1434-6052. ; 77:10
-
Journal article (peer-reviewed)abstract
- IceCube is a neutrino observatory deployed in the glacial ice at the geographic South Pole. The nu(mu) energy unfolding described in this paper is based on data taken with IceCube in its 79-string configuration. A sample of muon neutrino charged-current interactions with a purity of 99.5% was selected by means of amultivariate classification process based on machine learning. The subsequent unfolding was performed using the software TRUEE. The resulting spectrum covers an E-nu-range of more than four orders of magnitude from 125 GeV to 3.2 PeV. Compared to the Honda atmospheric neutrino flux model, the energy spectrum shows an excess of more than 1.9 sigma in four adjacent bins for neutrino energies E-nu >= 177.8 TeV. The obtained spectrum is fully compatible with previous measurements of the atmospheric neutrino flux and recent IceCube measurements of a flux of high-energy astrophysical neutrinos.
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| 32. |
- Aartsen, M. G., et al.
(author)
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Observation And Characterization Of A Cosmic Muon Neutrino Flux From The Northern Hemisphere Using Six Years Of Icecube Data
- 2016
-
In: Astrophysical Journal. - : Institute of Physics Publishing (IOPP). - 0004-637X .- 1538-4357. ; 833:1
-
Journal article (peer-reviewed)abstract
- The IceCube Collaboration has previously discovered a high-energy astrophysical neutrino flux using neutrino events with interaction vertices contained within the instrumented volume of the IceCube detector. We present a complementary measurement using charged current muon neutrino events where the interaction vertex can be outside this volume. As a consequence of the large muon range the effective area is significantly larger but the field of view is restricted to the Northern Hemisphere. IceCube data from 2009 through 2015 have been analyzed using a likelihood approach based on the reconstructed muon energy and zenith angle. At the highest neutrino energies between 194 TeV and 7.8 PeV a significant astrophysical contribution is observed, excluding a purely atmospheric origin of these events at 5.6 sigma significance. The data are well described by an isotropic, unbroken power-law flux with a normalization at 100 TeV neutrino energy of (0.90(-0.27)(+0.30)) x 10(-18) GeV-1 cm(-2) s(-1) sr(-1) and a hard spectral index of gamma = 2.13 +/- 0.13. The observed spectrum is harder in comparison to previous IceCube analyses with lower energy thresholds which may indicate a break in the astrophysical neutrino spectrum of unknown origin. The highest-energy event observed has a reconstructed muon energy of (4.5 +/- 1.2) PeV which implies a probability of less than 0.005% for this event to be of atmospheric origin. Analyzing the arrival directions of all events with reconstructed muon energies above 200 TeV no correlation with known gamma-ray sources was found. Using the high statistics of atmospheric neutrinos we report the current best constraints on a prompt atmospheric muon neutrino flux originating from charmed meson decays which is below 1.06 in units of the flux normalization of the model in Enberg et al.
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| 33. |
- Aartsen, M. G., et al.
(author)
-
PINGU : a vision for neutrino and particle physics at the South Pole
- 2017
-
In: Journal of Physics G. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 44:5
-
Journal article (peer-reviewed)abstract
- The Precision IceCube Next Generation Upgrade (PINGU) is a proposed low-energy in-fill extension to the IceCube Neutrino Observatory. With detection technology modeled closely on the successful IceCube example, PINGU will provide a 6 Mton effective mass for neutrino detection with an energy threshold of a few GeV. With an unprecedented sample of over 60 000 atmospheric neutrinos per year in this energy range, PINGU will make highly competitive measurements of neutrino oscillation parameters in an energy range over an order of magnitude higher than long-baseline neutrino beam experiments. PINGU will measure the mixing parameters theta(23) and Delta m(32)(2), including the octant of theta(23) for a wide range of values, and determine the neutrino mass ordering at 3 sigma median significance within five years of operation. PINGU's high precision measurement of the rate of nu(T) appearance will provide essential tests of the unitarity of the 3 x 3 PMNS neutrino mixing matrix. PINGU will also improve the sensitivity of searches for low mass dark matter in the Sun, use neutrino tomography to directly probe the composition of the Earth's core, and improve IceCube's sensitivity to neutrinos from Galactic supernovae. Reoptimization of the PINGU design has permitted substantial reduction in both cost and logistical requirements while delivering performance nearly identical to configurations previously studied.
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| 34. |
- Aartsen, M. G., et al.
(author)
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Search For Sources Of High-Energy Neutrons With Four Years Of Data From The Icetop Detector
- 2016
-
In: Astrophysical Journal. - : IOP PUBLISHING LTD. - 0004-637X .- 1538-4357. ; 830:2
-
Journal article (peer-reviewed)abstract
- IceTop is an air-shower array located on the Antarctic ice sheet at the geographic South Pole. IceTop can detect an astrophysical flux of neutrons from Galactic sources as an excess of cosmic-ray air showers arriving from the source direction. Neutrons are undeflected by the Galactic magnetic field and can typically travel 10 (E/PeV) pc before decay. Two searches are performed using 4 yr of the IceTop data set to look for a statistically significant excess of events with energies above 10 PeV (10(16) eV) arriving within a small solid angle. The all-sky search method covers from -90 degrees to approximately -50 degrees in declination. No significant excess is found. A targeted search is also performed, looking for significant correlation with candidate sources in different target sets. This search uses a higher-energy cut (100 PeV) since most target objects lie beyond 1 kpc. The target sets include pulsars with confirmed TeV energy photon fluxes and high-mass X-ray binaries. No significant correlation is found for any target set. Flux upper limits are determined for both searches, which can constrain Galactic neutron sources and production scenarios.
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| 35. |
- Aartsen, M. G., et al.
(author)
-
The IceCube Neutrino Observatory : instrumentation and online systems
- 2017
-
In: Journal of Instrumentation. - : IOP PUBLISHING LTD. - 1748-0221. ; 12
-
Journal article (peer-reviewed)abstract
- The IceCube Neutrino Observatory is a cubic-kilometer-scale high-energy neutrino detector built into the ice at the South Pole. Construction of IceCube, the largest neutrino detector built to date, was completed in 2011 and enabled the discovery of high-energy astrophysical neutrinos. We describe here the design, production, and calibration of the IceCube digital optical module (DOM), the cable systems, computing hardware, and our methodology for drilling and deployment. We also describe the online triggering and data filtering systems that select candidate neutrino and cosmic ray events for analysis. Due to a rigorous pre-deployment protocol, 98.4% of the DOMs in the deep ice are operating and collecting data. IceCube routinely achieves a detector uptime of 99% by emphasizing software stability and monitoring. Detector operations have been stable since construction was completed, and the detector is expected to operate at least until the end of the next decade.
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| 36. |
- Aartsen, M. G., et al.
(author)
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The IceCube realtime alert system
- 2017
-
In: Astroparticle physics. - : Elsevier BV. - 0927-6505 .- 1873-2852. ; 92, s. 30-41
-
Journal article (peer-reviewed)abstract
- Although high-energy astrophysical neutrinos were discovered in 2013, their origin is still unknown. Aiming for the identification of an electromagnetic counterpart of a rapidly fading source, we have implemented a realtime analysis framework for the IceCube neutrino observatory. Several analyses selecting neutrinos of astrophysical origin are now operating in realtime at the detector site in Antarctica and are producing alerts for the community to enable rapid follow-up observations. The goal of these observations is to locate the astrophysical objects responsible for these neutrino signals. This paper highlights the infrastructure in place both at the South Pole site and at IceCube facilities in the north that have enabled this fast follow-up program to be implemented. Additionally, this paper presents the first realtime analyses to be activated within this framework, highlights their sensitivities to astrophysical neutrinos and background event rates, and presents an outlook for future discoveries.
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| 37. |
- Abbasi, R., et al.
(author)
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IceCat-1: The IceCube Event Catalog of Alert Tracks
- 2023
-
In: Astrophysical Journal, Supplement Series. - : IOP Publishing Ltd. - 1538-4365 .- 0067-0049. ; 269:1
-
Journal article (peer-reviewed)abstract
- We present a catalog of likely astrophysical neutrino track-like events from the IceCube Neutrino Observatory. IceCube began reporting likely astrophysical neutrinos in 2016, and this system was updated in 2019. The catalog presented here includes events that were reported in real time since 2019, as well as events identified in archival data samples starting from 2011. We report 275 neutrino events from two selection channels as the first entries in the catalog, the IceCube Event Catalog of Alert Tracks, which will see ongoing extensions with additional alerts. The Gold and Bronze alert channels respectively provide neutrino candidates with a 50% and 30% probability of being astrophysical, on average assuming an astrophysical neutrino power-law energy spectral index of 2.19. For each neutrino alert, we provide the reconstructed energy, direction, false-alarm rate, probability of being astrophysical in origin, and likelihood contours describing the spatial uncertainty in the alert's reconstructed location. We also investigate a directional correlation of these neutrino events with gamma-ray and X-ray catalogs, including 4FGL, 3HWC, TeVCat, and Swift-BAT.
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| 38. |
- Burisch, J., et al.
(author)
-
Environmental factors in a population-based inception cohort of inflammatory bowel disease patients in Europe : An ECCO-EpiCom study
- 2014
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In: Journal of Crohn's & Colitis. - : Oxford University Press. - 1873-9946 .- 1876-4479. ; 8:7, s. 607-616
-
Journal article (peer-reviewed)abstract
- Background and Aims: The incidence of inflammatory bowel disease (IBD) is increasing in Eastern Europe possibly due to changes in environmental factors towards a more "westernised" standard of Living. The aim of this study was to investigate differences in exposure to environmental factors prior to diagnosis in Eastern and Western European IBD patients.Methods: The EpiCom cohort is a population-based, prospective inception cohort of 1560 unselected IBD patients from 31 European countries covering a background population of 10.1 million. At the time of diagnosis patients were asked to complete an 87-item questionnaire concerning environmental factors.Results: A total of 1182 patients (76%) answered the questionnaire, 444 (38%) had Crohn's disease (CD), 627 (53%) ulcerative colitis (UC), and 111 (9%) IBD unclassified. No geographic differences regarding smoking status, caffeine intake, use of oral contraceptives, or number of first-degree relatives with IBD were found. Sugar intake was higher in CD and UC patients from Eastern Europe than in Western Europe while fibre intake was lower (p < 0.01). Daily consumption of fast food as well as appendectomy before the age of 20 was more frequent in Eastern European than in Western European UC patients (p < 0.01). Eastern European CD and UC patients had received more vaccinations and experienced fewer childhood infections than Western European patients (p < 0.01).Conclusions: In this European population-based inception cohort of unselected IBD patients, Eastern and Western European patients differed in environmental factors prior to diagnosis. Eastern European patients exhibited higher occurrences of suspected risk factors for IBD included in the Western lifestyle. (C) 2013 European Crohn's and Colitis Organisation. Published by Elsevier B.V. All rights reserved.
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| 39. |
- Burisch, J., et al.
(author)
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Health care and patients' education in a European inflammatory bowel disease inception cohort : an ECCO-EpiCom study
- 2014
-
In: Journal of Crohn's & Colitis. - : Oxford University Press (OUP). - 1873-9946 .- 1876-4479. ; 8:8, s. 811-818
-
Journal article (peer-reviewed)abstract
- Background and Aims: The EpiCom study and inception cohort was initiated in 2010 in 31 centers from 14 Western and 8 Eastern European countries, covering a 10.1 million person background population. Our aim was to investigate whether there is a difference between Eastern and Western Europe in health care and education of patients with inflammatory bowel disease (IBD).Methods: A quality of care (QoC) questionnaire was developed in the EpiCom group consisting of 16 questions covering 5 items: time interval between the onset of symptoms and diagnosis, information, education, empathy and access to health care providers.Results: Of 1,515 patients, 947 (217 east/730 west) answered the QoC questionnaire. Only 23% of all patients had knowledge about IBD before diagnosis. In Eastern Europe, significantly more patients searched out information about IBD themselves (77% vs. 68%, p < 0.05), the main source was the Internet (92% vs. 88% p = 0.23). In Western Europe, significantly more patients were educated by nurses (19% vs. 1%, p < 0.05), while in Eastern Europe, gastroenterologists were easier to contact (80% vs. 68%, p < 0.05).Conclusion: Health care differed significantly between Eastern and Western Europe in all items, but satisfaction rates were high in both geographic regions. Because of the low awareness and the rising incidence of IBD, general information should be the focus of patient organizations and medical societies. In Western Europe IBD nurses play a very important role in reducing the burden of patient management. (c) 2014 European Crohn's and Colitis Organisation. Published by Elsevier B.V. All rights reserved.
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| 40. |
- Burisch, J., et al.
(author)
-
Health-related quality of life improves during one year of medical and surgical treatment in a European population-based inception cohort of patients with Inflammatory Bowel Disease : An ECCO-EpiCom study
- 2014
-
In: Journal of Crohn's & Colitis. - Oxford, United Kingdom : Oxford University Press. - 1873-9946 .- 1876-4479. ; 8:9, s. 1030-1042
-
Journal article (peer-reviewed)abstract
- Background & Aims: Health-related quality of life (HRQoL) is impaired in patients with Inflammatory Bowel Disease (IBD). The aim was prospectively to assess and validate the pattern of HRQoL in an unselected, population-based inception cohort of IBD patients from Eastern and Western Europe.Methods: The EpiCom inception cohort consists of 1560 IBD patients from 31 European centres covering a background population of approximately 10.1 million. Patients answered the disease specific Short Inflammatory Bowel Disease Questionnaire (SIBDQ) and generic Short Form 12 (SF-12) questionnaire at diagnosis and after one year of follow-up.Results: In total, 1079 patients were included in this study. Crohn's disease (CD) patients mean SIBDQ scores improved from 45.3 to 55.3 in Eastern Europe and from 44.9 to 53.6 in Western Europe. SIBDQ scores for ulcerative colitis (UC) patients improved from 44.9 to 57.4 and from 48.8 to 55.7, respectively. UC patients needing surgery or biologicals had lower SIBDQ scores before and after compared to the rest, while biological therapy improved SIBDQ scores in CD. CD and UC patients in both regions improved all SF-12 scores. Only Eastern European UC patients achieved SF-12 summary scores equal to or above the normal population.Conclusion: Medical and surgical treatment improved HRQoL during the first year of disease. The majority of IBD patients in both Eastern and Western Europe reported a positive perception of disease-specific but not generic HRQoL. Biological therapy improved HRQoL in CD patients, while UC patients in need of surgery or biological therapy experienced lower perceptions of HRQoL than the rest.
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| 41. |
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| 42. |
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| 43. |
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| 44. |
- Gaulton, Kyle J, et al.
(author)
-
Genetic fine mapping and genomic annotation defines causal mechanisms at type 2 diabetes susceptibility loci.
- 2015
-
In: Nature Genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 47:12, s. 1415-1415
-
Journal article (peer-reviewed)abstract
- We performed fine mapping of 39 established type 2 diabetes (T2D) loci in 27,206 cases and 57,574 controls of European ancestry. We identified 49 distinct association signals at these loci, including five mapping in or near KCNQ1. 'Credible sets' of the variants most likely to drive each distinct signal mapped predominantly to noncoding sequence, implying that association with T2D is mediated through gene regulation. Credible set variants were enriched for overlap with FOXA2 chromatin immunoprecipitation binding sites in human islet and liver cells, including at MTNR1B, where fine mapping implicated rs10830963 as driving T2D association. We confirmed that the T2D risk allele for this SNP increases FOXA2-bound enhancer activity in islet- and liver-derived cells. We observed allele-specific differences in NEUROD1 binding in islet-derived cells, consistent with evidence that the T2D risk allele increases islet MTNR1B expression. Our study demonstrates how integration of genetic and genomic information can define molecular mechanisms through which variants underlying association signals exert their effects on disease.
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| 45. |
- Hagert, C., et al.
(author)
-
Chronic Active Arthritis Driven by Macrophages Without Involvement of T Cells : A Novel Experimental Model of Rheumatoid Arthritis
- 2018
-
In: Arthritis & Rheumatology. - Hoboken : Wiley. - 2326-5191 .- 2326-5205 .- 1529-0131. ; 70:8, s. 1343-1353
-
Journal article (peer-reviewed)abstract
- OBJECTIVE: To develop a new chronic rheumatoid arthritis model that is driven by the innate immune system. METHODS: Injection of a cocktail of 4 monoclonal antibodies against type II collagen, followed on days 5 and 60 by intraperitoneal injections of mannan (from Saccharomyces cerevisiae), was used to induce development of chronic arthritis in B10.Q mice. The role of the innate immune system as compared to the adaptive immune system in this arthritis model was investigated using genetically modified mouse strains. RESULTS: A new model of chronic relapsing arthritis was characterized in B10.Q mice, in which a persistently active, chronic disease was found. This relapsing disease was driven by macrophages lacking the ability to mount a reactive oxygen species response against pathogens, and was associated with the classical/alternative pathway, but not the lectin pathway, of complement activation. The disease was independent of Fcgamma receptor type III, and also independent of the activity of adaptive immune cells (B and T cells), indicating that the innate immune system, involving complement activation, could be the sole driver of chronicity. CONCLUSION: Chronic active arthritis can be driven innately by macrophages without the involvement of T and B cells in the adaptive immune system.
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| 46. |
- Hechler, O., et al.
(author)
-
On the use of duplex stainless steels in bridge construction
- 2008
-
In: Bridge Maintenance, Safety Management, Health Monitoring and Informatics. - Boca Raton, Fla : Taylor and Francis Group. - 9780415468442
-
Conference paper (peer-reviewed)abstract
- Maintenance and the related costs in the life time of existing structures are an ever growing problem and bridges are no exception to this rule. Much of the maintenance costs are related to corrosion of steel members. Especially when steel and composite bridges are built in aggressive environments (e.g. close to seawater or in industrial atmospheres) these costs become of major importance. However also concrete bridges are concerned as the re-bars in concrete decks may be subjected to corrosion caused by chloride ingress from de-icing salt or seawater. Consequently the use of a material providing high mechanical properties with a sufficient corrosion resistance for the application in these aggressive environments would lead to economic and durable construction. Further the maintenance costs become predictable, which would increase the quality of the bridge management. Duplex stainless steel is this material with sufficient yield strength, stiffness and toughness as well as an excellent durability in aggressive environments. With a targeted material choice, innovative construction solution may be achieved. However, high material costs, gaps in common knowledge, e.g. on fatigue, as well as fabrication aspects are preventing a wider application of these steels in bridge construction.
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| 47. |
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| 48. |
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| 49. |
- Kankare, E., et al.
(author)
-
Search for transient optical counterparts to high-energy IceCube neutrinos with Pan-STARRS1
- 2019
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 626
-
Journal article (peer-reviewed)abstract
- In order to identify the sources of the observed diffuse high-energy neutrino flux, it is crucial to discover their electromagnetic counterparts. To increase the sensitivity of detecting counterparts of transient or variable sources by telescopes with a limited field of view, IceCube began releasing alerts for single high-energy (E-v > 60 TeV) neutrino detections with sky localisation regions of order 1 degrees radius in 2016. We used Pan-STARRS1 to follow-up five of these alerts during 2016-2017 to search for any optical transients that may be related to the neutrinos. Typically 10-20 faint m(ip1) less than or similar to 22.5 mag) extragalactic transients are found within the Pan-STARRS1 footprints and are generally consistent with being unrelated field supernovae (SNe) and AGN. We looked for unusual properties of the detected transients, such as temporal coincidence of explosion epoch with the IceCube timestamp, or other peculiar light curve and physical properties. We found only one transient that had properties worthy of a specific follow-up. In the Pan-STARRS1 imaging for IceCube-160427A (probability to be of astrophysical origin of similar to 50%), we found a SN PS16cgx, located at 10.0' from the nominal IceCube direction. Spectroscopic observations of PS16cgx showed that it was an H-poor SN at redshift z = 0.2895 +/- 0.0001. The spectra and light curve resemble some high-energy Type Ic SNe, raising the possibility of a jet driven SN with an explosion epoch temporally coincident with the neutrino detection. However, distinguishing Type Ia and Type Ic SNe at this redshift is notoriously difficult. Based on all available data we conclude that the transient is more likely to be a Type Ia with relatively weak Sin absorption and a fairly normal rest-frame r-band light curve. If, as predicted, there is no high-energy neutrino emission from Type Ia SNe, then PS16cgx must be a random coincidence, and unrelated to the IceCube-160427A. We find no other plausible optical transient for any of the five IceCube events observed down to a 5 sigma limiting magnitude of mip1 approximate to 22 mag, between 1 day and 25 days after detection.
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| 50. |
- Kopp, J, et al.
(author)
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Regulation of neuropeptide Y Y1 receptors by testosterone in vascular smooth muscle cells in rat testis
- 2008
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In: Neuroendocrinology. - : S. Karger AG. - 1423-0194 .- 0028-3835. ; 88:3, s. 216-226
-
Journal article (peer-reviewed)abstract
- It is well established that testosterone and neuropeptide Y (NPY), via its Y1 receptor (Y1R), are involved in the central control of the gonadotrope axis in male rats. Here we examined if a similar interaction also occurs in the male peripheral reproductive target organ, the testes. Expression of the Y1R transcript and protein and changes in testicular microcirculation were studied in normal rats and 12 days following hypophysectomy with and without testosterone substitution (1 or 25 mg s.c.). In situ hybridization and immunohistochemistry showed strong expression of, respectively, Y1R messenger RNA (Y1R mRNA) and Y1R-like immunoreactivity (Y1R-LI) in vascular smooth muscles in the testes of control and hypophysectomized rats treated with testosterone, but was not seen without testosterone substitution. In parallel, control animals and hypophysectomized, testosterone-supplemented rats showed a strong (approximately 40%) decrease in testicular blood flow following intratesticular (i.t.) injection of the Y1-R agonists, [Leu<sup>31</sup>, Pro<sup>34</sup>]NPY, [<i>D</i>-Arg<sup>25</sup>]NPY or NPY, an effect which was completely blocked by prior intravenous administration of the Y1R antagonist, BIBP3226. No significant change in testicular blood flow following i.t. injection of NPY was seen in hypophysectomized rats without testosterone substitution. These findings suggest that the high levels of Y1R mRNA and Y1R-LI in the testes reflect expression of functional Y1Rs mediating vasoconstriction, and that testosterone regulates expression of functional Y1Rs.
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