| 1901. |
- Zhu, X., et al.
(författare)
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A Cation-Methylene-Phenyl Sequence Encodes Programmable Poly(Ionic Liquid) Coacervation and Robust Underwater Adhesion
- 2022
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 32:2
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Tidskriftsartikel (refereegranskat)abstract
- Appropriate deciphering and translation of sequence-dependent function in proteins is inspired by the cation–π interaction that is increasingly implicated in marine adhesives and membraneless organelles. A simplified cation-methylene-phenyl (C-M-P) sequence which enables triggerable poly(ionic liquid) coacervation is reported for the first time. Synthesis of the C-M-P structure motif requires only a one-step quaternization, which is facile compared to the linear sequence of distinct repeating units in model proteins and sequence-controlled polymers. The C-M-P code confers modular coacervation and advanced wet adhesion to task-specific copolymers. It allows for exceptional underwater adhesion to various submerged substrates including glass (≈1 MPa) and porcine skins (140 KPa), paving the way for prospective adhesive applications in physiological saline and underwater marine salvage. This work introduces a powerful code that, in addition to combining the advantageous adaptive adhesive and phase properties of proteins, reduces the complexity in sequence design for programmable coacervates.
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| 1902. |
- Ajello, M., et al.
(författare)
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Bright Gamma-Ray Flares Observed in GRB 131108A
- 2019
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Ingår i: Astrophysical Journal Letters. - : Institute of Physics (IOP). - 2041-8205 .- 2041-8213. ; 886:2
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Tidskriftsartikel (refereegranskat)abstract
- GRB 131108A is a bright long gamma-ray burst (GRB) detected by the Large Area Telescope and the Gamma-ray Burst Monitor on board the Fermi Gamma-ray Space Telescope. Dedicated temporal and spectral analyses reveal three ?-ray flares dominating above 100 MeV, which are not directly related to the prompt emission in the Gamma-ray Burst Monitor band (10 keV?10 MeV). The high-energy light curve of GRB 131108A (100 MeV?10 GeV) shows an unusual evolution: a steep decay, followed by three flares with an underlying emission, and then a long-lasting decay phase. The detailed analysis of the ?-ray flares finds that the three flares are 6?20 times brighter than the underlying emission and are similar to each other. The fluence of each flare, (1.6?2.0)10(?6) erg cm(?2), is comparable to that of emission during the steep decay phase, 1.710(?6) erg cm(?2). The total fluence from three ?-ray flares is 5.310(?6) erg cm(?2). The three ?-ray flares show properties similar to the usual X-ray flares that are sharp flux increases, occurring in ?50% of afterglows, in some cases well after the prompt emission. Also, the temporal and spectral indices during the early steep decay phase and the decaying phase of each flare show the consistency with a relation of the curvature effect (
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| 1903. |
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| 1904. |
- Aliu, E., et al.
(författare)
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Multiwavelength Observations of the TeV Binary LS I +61° 303 with VERITAS, Fermi-LAT, and Swift/XRT during a TeV Outburst
- 2013
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Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 779:1
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Tidskriftsartikel (refereegranskat)abstract
- We present the results of a multiwavelength observational campaign on the TeV binary system LS I +61° 303 with the VERITAS telescope array (>200 GeV), Fermi-LAT (0.3-300 GeV), and Swift/XRT (2-10 keV). The data were taken from 2011 December through 2012 January and show a strong detection in all three wavebands. During this period VERITAS obtained 24.9 hr of quality selected livetime data in which LS I +61° 303 was detected at a statistical significance of 11.9σ. These TeV observations show evidence for nightly variability in the TeV regime at a post-trial significance of 3.6σ. The combination of the simultaneously obtained TeV and X-ray fluxes do not demonstrate any evidence for a correlation between emission in the two bands. For the first time since the launch of the Fermi satellite in 2008, this TeV detection allows the construction of a detailed MeV-TeV spectral energy distribution from LS I +61° 303. This spectrum shows a distinct cutoff in emission near 4 GeV, with emission seen by the VERITAS observations following a simple power-law above 200 GeV. This feature in the spectrum of LS I +61° 303, obtained from overlapping observations with Fermi-LAT and VERITAS, may indicate that there are two distinct populations of accelerated particles producing the GeV and TeV emission.
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| 1905. |
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| 1906. |
- Andersson, V., et al.
(författare)
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Large-Area Balloon-Borne Polarized Gamma Ray Observer (PoGO)
- 2005
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Ingår i: Proceedings of the 22nd Texas Symposium on Relativistic Astrophysics at Stanford. ; , s. 736-743
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Konferensbidrag (refereegranskat)abstract
- We are developing a new balloon-borne instrument (PoGO), to measure polarization of soft gamma rays (30-200 keV) using asymmetry in azimuth angle distribution of Compton scattering. PoGO is designed to detect 10 % polarization in 100mCrab sources in a 6-8 hour observation and bring a new dimension to studies on gamma ray emission/transportation mechanism in pulsars, AGNs, black hole binaries, and neutron star surface. The concept is an adaptation to polarization measurements of well-type phoswich counter consisting of a fast plastic scintillator (the detection part), a slow plastic scintillator (the active collimator) and a BGO scintillator (the bottom anti-counter). PoGO consists of close-packed array of 217 hexagonal well-type phoswich counters and has a narrow field-of-view (~ 5 deg2) to reduce possible source confusion. A prototype instrument has been tested in the polarized soft gamma-ray beams at Advanced Photon Source (ANL) and at Photon Factory (KEK). On the results, the polarization dependence of EGS4 has been validated and that of Geant4 has been corrected.
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| 1907. |
- Andreoli, L., et al.
(författare)
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COVID-19 VACCINE SAFETY DURING PREGNANCY AND BREASTFEEDING IN WOMEN WITH AUTOIMMUNE DISEASES : RESULTS FROM THE COVAD STUDY
- 2023
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Ingår i: Annals of the Rheumatic Diseases. - : HighWire Press. - 0003-4967 .- 1468-2060. ; 82:Suppl. 1, s. 56-57
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: COVID-19 vaccine hesitancy among pregnant and breastfeeding women with autoimmune diseases (AID) is often attributed to the fear of adverse events (AE) and disease flares (DF). No data are available regarding COVID-19 vaccine safety in this population.Objectives: We aimed at describing delayed-onset (>7 days) vaccine-related AE (minor and major), DF, and related AID treatment modifications from the COVID-19 Vaccination in Autoimmune Diseases (COVAD) study.Methods: Among complete responses from 9201 participants as of June 21, 2022, 6787 (73.8%) were women. Six subgroups were identified upon diagnosis of AID vs healthy controls (HC) and their pregnancy/breastfeeding status at the time of any dose of vaccine (Figure 1).Results: Forty pregnant and 52 breastfeeding AID patients were identified and their vaccination rates (at least one dose) was 100% and 96.2%, respectively (Table 1). Overall AE, minor AE, and major AE were reported significantly more frequently by pregnant than non-pregnant patients (45% vs. 26%, p=0.01; 40% vs. 25.9%, p=0.03; 17.5% vs. 4.6%, p<0.01), but no difference was found in comparison with pregnant HC. No difference was observed between breastfeeding patients and HC. Post-vaccination DF were reported by 17.5% of pregnant and 20% of breastfeeding patients, and by 18% of age- and disease-matched control patients (n=2315). All DF in pregnant/breastfeeding patients were managed with glucocorticoids and a fifth of them required initiation or change in immunosuppressive treatment.Conclusion: This study provides the first insights into the safety of COVID-19 vaccination during the antenatal period in women with AID. While AEs were more commonly reported by pregnant patients with AID, these were no higher than among pregnant healthy controls without AID. These observations are reassuring, likely to strengthen physician-patient communication and overcome hesitancy as the benefits for the mother and fetus by passive immunization are likely to overweigh the potential risks of AE and DF.Reference: [1]Fazal ZZ, et al; COVAD Study Group. COVAD survey 2 long-term outcomes: unmet need and protocol. Rheumatol Int 2022; 42:2151-2158.
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| 1908. |
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| 1909. |
- Anker, A., et al.
(författare)
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Improving sensitivity of the ARIANNA detector by rejecting thermal noise with deep learning
- 2022
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Ingår i: Journal of Instrumentation. - : IOP Publishing. - 1748-0221. ; 17:3
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Tidskriftsartikel (refereegranskat)abstract
- The ARIANNA experiment is an Askaryan detector designed to record radio signals induced by neutrino interactions in the Antarctic ice. Because of the low neutrino flux at high energies (E-nu > 10(16 )eV), the physics output is limited by statistics. Hence, an increase in sensitivity significantly improves the interpretation of data and offers the ability to probe new parameter spaces. The amplitudes of the trigger threshold are limited by the rate of triggering on unavoidable thermal noise fluctuations. We present a real-time thermal noise rejection algorithm that enables the trigger thresholds to be lowered, which increases the sensitivity to neutrinos by up to a factor of two (depending on energy) compared to the current ARIANNA capabilities. A deep learning discriminator, based on a Convolutional Neural Network (CNN), is implemented to identify and remove thermal events in real time. We describe a CNN trained on MC data that runs on the current ARIANNA microcomputer and retains 95% of the neutrino signal at a thermal noise rejection factor of 10(5), compared to a template matching procedure which reaches only 10(2) for the same signal efficiency. Then the results are verified in a lab measurement by feeding in generated neutrino-like signal pulses and thermal noise directly into the ARIANNA data acquisition system. Lastly, the same CNN is used to classify cosmic-rays events to make sure they are not rejected. The network classified 102 out of 104 cosmic-ray events as signal.
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| 1910. |
- Anker, A., et al.
(författare)
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Measuring the polarization reconstruction resolution of the ARIANNA neutrino detector with cosmic rays
- 2022
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Ingår i: Journal of Cosmology and Astroparticle Physics. - : IOP Publishing. - 1475-7516. ; :4
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Tidskriftsartikel (refereegranskat)abstract
- The ARIANNA detector is designed to detect neutrinos with energies above 10(17) eV. Due to the similarities in generated radio signals, cosmic rays are often used as test beams for neutrino detectors. Some ARIANNA detector stations are equipped with antennas capable of detecting air showers. Since the radio emission properties of air showers are well understood, and the polarization of the radio signal can be predicted from the arrival direction, cosmic rays can be used as a proxy to assess the reconstruction capabilities of the ARIANNA neutrino detector. We report on dedicated efforts of reconstructing the polarization of cosmic-ray radio pulses. After correcting for difference in hardware, the two stations used in this study showed similar performance in terms of event rate and agreed with simulation. Subselecting high quality cosmic rays, the polarizations of these cosmic rays were reconstructed with a resolution of 2.5 degrees (68% containment), which agrees with the expected value obtained from simulation. A large fraction of this resolution originates from uncertainties in the predicted polarization because of the contribution of the subdominant Askaryan effect in addition to the dominant geomagnetic emission. Subselecting events with a zenith angle greater than 70 degrees removes most influence of the Askaryan emission, and, with limited statistics, we found the polarization uncertainty is reduced to 1.3 degrees (68% containment).
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