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 5×10^{5} GeV to above 10^{11} GeV. Two neutrino-induced events with an estimated deposited energy of (2.6±0.3)×10^{6} GeV, the highest neutrino energy observed so far, and (7.7±2.0)×10^{5} GeV were detected. The atmospheric background-only hypothesis of detecting these events is rejected at 3.6σ. 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 γ-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.
We report on measurements of the all-particle cosmic ray energy spectrum and composition in the PeV to EeV energy range using 3 years of data from the IceCube Neutrino Observatory. The IceTop ...detector measures cosmic ray induced air showers on the surface of the ice, from which the energy spectrum of cosmic rays is determined by making additional assumptions about the mass composition. A separate measurement is performed when IceTop data are analyzed in coincidence with the high-energy muon energy loss information from the deep in-ice IceCube detector. In this measurement, both the spectrum and the mass composition of the primary cosmic rays are simultaneously reconstructed using a neural network trained on observables from both detectors. The performance and relative advantages of these two distinct analyses are discussed, including the systematic uncertainties and the dependence on the hadronic interaction models, and both all-particle spectra as well as individual spectra for elemental groups are presented.
Objectives: Immunoglobulin (Ig)G4-related disease is a recently proposed systemic disorder that includes autoimmune pancreatitis (AIP), Mikulicz's disease, and various other organ lesions. In the ...present retrospective study, we examined whether thyroid lesions should also be included in IgG4-related disease (Ig4-RD) under the new term IgG4-related thyroiditis.
Method: We enrolled 114 patients with Ig4-RD, including 92 patients with AIP, 15 patients with Mikulicz's disease, and seven patients with IgG4-related cholangitis, and analysed clinical findings, function, serum values of activity markers, computed tomography (CT) images, and histology of the thyroid gland.
Results: Among the 22 patients (19%) in our cohort who were found to have hypothyroidism thyroid stimulating hormone (TSH) > 4 mIU/L, 11 patients had clinical hypothyroidism free thyroxine (FT4) < 1 ng/dL and 11 patients had subclinical hypothyroidism (FT4 ≥ 1 ng/dL). Serum concentrations of IgG, IgG4, circulating immune complex (CIC), and β2-microglobulin (β2-MG) were significantly higher in the hypothyroidism group compared with the remaining 92 euthyroid patients, and serum C3 concentration was significantly lower. After prednisolone treatment, TSH values had decreased significantly (p = 0.005) in this group and FT4 values had increased significantly (p = 0.047). CT images showed that the thyroid glands of patients with clinical hypothyroidism had a significantly greater volume than those of the euthyroid and other groups. Pathological analysis of one resected thyroid gland disclosed a focused lesion with infiltration of lymphocytes and IgG4-bearing plasma cells and loss of thyroid follicles.
Conclusions: Thyroid lesions associated with hypothyroidism can be considered as a new disease termed IgG4-related thyroiditis. Awareness of this condition should lead to appropriate corticosteroid treatment that may prevent progression to a fibrous state.
Spherical Fe-oxide concretions on Earth, especially in Utah, USA, have been investigated as an analog of hematite spherules found in Meridiani Planum on Mars to support interpretations of water-rock ...interactions in early Mars. Although several formation mechanisms have been proposed for the Fe-oxide concretions on Earth, it is still unclear whether these mechanisms are viable because a precise formation process and precursor of the concretions are missing. This paper presents evidence that Fe-oxide concretions in Utah and newly found Fe-oxide concretions in Mongolia had spherical calcite concretions as precursors. Different formation stages of calcite and Fe-oxide concretions observed, both in Utah and Mongolia, indicate that calcite concretions initially formed within eolian sandstone strata and were dissolved by infiltrating Fe-rich acidic waters to form spherical FeO(OH) crusts due to pH buffering. The similarity between these Fe-oxide concretions on Earth and the hematite spherule occurrences in Meridiani Planum, combined with evidence of acid sulfate water influences on Mars, suggest that the hematite spherules also formed from dissolution of preexisting carbonate spherules possibly formed under a dense carbon dioxide early martian atmosphere.
With the observation of high-energy astrophysical neutrinos by the IceCube Neutrino Observatory, interest has risen in models of PeV-mass decaying dark matter particles to explain the observed flux. ...We present two dedicated experimental analyses to test this hypothesis. One analysis uses 6 years of IceCube data focusing on muon neutrino ‘track’ events from the Northern Hemisphere, while the second analysis uses 2 years of ‘cascade’ events from the full sky. Known background components and the hypothetical flux from unstable dark matter are fitted to the experimental data. Since no significant excess is observed in either analysis, lower limits on the lifetime of dark matter particles are derived: we obtain the strongest constraint to date, excluding lifetimes shorter than
10
28
s
at 90% CL for dark matter masses above
10
TeV
.
This paper describes the response of the IceCube neutrino telescope located at the geographic south pole to outbursts of MeV neutrinos from the core collapse of nearby massive stars. IceCube was ...completed in December 2010 forming a lattice of 5160 photomultiplier tubes that monitor a volume of ~1 km3 in the deep Antarctic ice for particle induced photons. The telescope was designed to detect neutrinos with energies greater than 100 GeV. Owing to subfreezing ice temperatures, the photomultiplier dark noise rates are particularly low. Hence IceCube can also detect large numbers of MeV neutrinos by observing a collective rise in all photomultiplier rates on top of the dark noise. With 2 ms timing resolution, IceCube can detect subtle features in the temporal development of the supernova neutrino burst. For a supernova at the galactic center, its sensitivity matches that of a background-free megaton-scale supernova search experiment. The sensitivity decreases to 20 standard deviations at the galactic edge (30 kpc) and 6 standard deviations at the Large Magellanic Cloud (50 kpc). IceCube is sending triggers from potential supernovae to the Supernova Early Warning System. The sensitivity to neutrino properties such as the neutrino hierarchy is discussed, as well as the possibility to
Abstract
Background
Commercial drivers suffering from excessive daytime sleepiness (EDS) have been identified as a major cause of road traffic accidents. Alcohol usage directly affects sleep, ...adversely affecting next-day alertness and performance.
Aims
To examine the relationship between alcohol consumption and EDS among commercial truck drivers in Japan and the implications of this on public health.
Methods
All participants in this cross-sectional study were commercial motor vehicle drivers from Tokyo and Niigata Prefecture. Participants completed a self-administered questionnaire with details of their age, body mass index, alcohol consumption, Epworth Sleepiness Scale (ESS) score and tobacco usage. Participants’ oxygen desaturation index was determined by a pulse oximetry device that participants took home.
Results
A total of 1422 males registered with the Japan Trucking Association and aged 20–69 years participated. The multivariate-adjusted odds ratio (OR) of EDS among participants aged <43 years was 0.81 (95% confidence interval (CI) 0.47–1.40) for light drinkers, 0.93 (95% CI 0.51–1.70) for moderate drinkers and 0.61 (95% CI 0.21–1.79) for heavy drinkers, compared to non-drinkers. The multivariate-adjusted OR among participants aged ≥43 years was 1.42 (95% CI 0.59–3.45) for light drinkers, 1.53 (95% CI 0.63–3.75) for moderate drinkers and 3.37 (95% CI 1.14–9.96) for heavy drinkers (P for interaction = 0.05).
Conclusion
We found that the association between ESS and alcohol intake was more evident among those aged ≥43 years, who reported higher levels of EDS with increased alcohol consumption.
The T2K experiment observes indications of ν(μ) → ν(e) appearance in data accumulated with 1.43×10(20) protons on target. Six events pass all selection criteria at the far detector. In a three-flavor ...neutrino oscillation scenario with |Δm(23)(2)| = 2.4×10(-3) eV(2), sin(2)2θ(23) = 1 and sin(2)2θ(13) = 0, the expected number of such events is 1.5±0.3(syst). Under this hypothesis, the probability to observe six or more candidate events is 7×10(-3), equivalent to 2.5σ significance. At 90% C.L., the data are consistent with 0.03(0.04) < sin(2)2θ(13) < 0.28(0.34) for δ(CP) = 0 and a normal (inverted) hierarchy.
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