| 1. |
- Abbasi, R., et al.
(författare)
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Observation of seasonal variations of the flux of high-energy atmospheric neutrinos with IceCube
- 2023
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Ingår i: European Physical Journal C. - : Springer. - 1434-6044 .- 1434-6052. ; 83:9
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Tidskriftsartikel (refereegranskat)abstract
- Atmospheric muon neutrinos are produced by meson decays in cosmic-ray-induced air showers. The flux depends on meteorological quantities such as the air temperature, which affects the density of air. Competition between decay and re-interaction of those mesons in the first particle production generations gives rise to a higher neutrino flux when the air density in the stratosphere is lower, corresponding to a higher temperature. A measurement of a temperature dependence of the atmospheric νμ flux provides a novel method for constraining hadronic interaction models of air showers. It is particularly sensitive to the production of kaons. Studying this temperature dependence for the first time requires a large sample of high-energy neutrinos as well as a detailed understanding of atmospheric properties. We report the significant (>10σ) observation of a correlation between the rate of more than 260,000 neutrinos, detected by IceCube between 2012 and 2018, and atmospheric temperatures of the stratosphere, measured by the Atmospheric Infrared Sounder (AIRS) instrument aboard NASA’s AQUA satellite. For the observed 10 % seasonal change of effective atmospheric temperature we measure a 3.5(3) % change in the muon neutrino flux. This observed correlation deviates by about 2-3 standard deviations from the expected correlation of 4.3 % as obtained from theoretical predictions under the assumption of various hadronic interaction models.
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| 2. |
- Abbasi, R., et al.
(författare)
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Limits on Neutrino Emission from GRB 221009A from MeV to PeV Using the IceCube Neutrino Observatory
- 2023
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Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 946:1
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Tidskriftsartikel (refereegranskat)abstract
- Gamma-ray bursts (GRBs) have long been considered a possible source of high-energy neutrinos. While no correlations have yet been detected between high-energy neutrinos and GRBs, the recent observation of GRB 221009A-the brightest GRB observed by Fermi-GBM to date and the first one to be observed above an energy of 10 TeV-provides a unique opportunity to test for hadronic emission. In this paper, we leverage the wide energy range of the IceCube Neutrino Observatory to search for neutrinos from GRB 221009A. We find no significant deviation from background expectation across event samples ranging from MeV to PeV energies, placing stringent upper limits on the neutrino emission from this source.
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| 3. |
- Perley, Daniel A., et al.
(författare)
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The fast, luminous ultraviolet transient AT2018cow : extreme supernova, or disruption of a star by an intermediate-mass black hole?
- 2019
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 484:1, s. 1031-1049
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Tidskriftsartikel (refereegranskat)abstract
- Wide-field optical surveys have begun to uncover large samples of fast (t(rise) less than or similar to 5 d), luminous (M-peak < 18), blue transients. While commonly attributed to the breakout of a supernova shock into a dense wind, the great distances to the transients of this class found so far have hampered detailed investigation of their properties. We present photometry and spectroscopy from a comprehensive worldwide campaign to observe AT 2018cow (ATLAS 18qqn), the first fast-luminous optical transient to be found in real time at low redshift. Our first spectra (<2 days after discovery) are entirely featureless. A very broad absorption feature suggestive of near-relativistic velocities develops between 3 and 8 days, then disappears. Broad emission features of H and He develop after >10 days. The spectrum remains extremely hot throughout its evolution, and the photospheric radius contracts with time (receding below R < 10 (14) cm after 1 month). This behaviour does not match that of any known supernova, although a relativistic jet within a fallback supernova could explain some of the observed features. Alternatively, the transient could originate from the disruption of a star by an intermediate-mass black hole, although this would require long-lasting emission of highly super-Eddington thermal radiation. In either case, AT 2018cow suggests that the population of fast luminous transients represents a new class of astrophysical event. Intensive follow-up of this event in its late phases, and of any future events found at comparable distance, will be essential to better constrain their origins.
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| 4. |
- Thornton, JS, et al.
(författare)
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Treating low back pain in athletes: a systematic review with meta-analysis
- 2021
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Ingår i: British journal of sports medicine. - : BMJ. - 1473-0480 .- 0306-3674. ; 55:12, s. 656-662
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Tidskriftsartikel (refereegranskat)abstract
- To summarise the evidence for non-pharmacological management of low back pain (LBP) in athletes, a common problem in sport that can negatively impact performance and contribute to early retirement.Data sourcesFive databases (EMBASE, Medline, CINAHL, Web of Science, Scopus) were searched from inception to September 2020. The main outcomes of interest were pain, disability and return to sport (RTS).ResultsAmong 1629 references, 14 randomised controlled trials (RCTs) involving 541 athletes were included. The trials had biases across multiple domains including performance, attrition and reporting. Treatments included exercise, biomechanical modifications and manual therapy. There were no trials evaluating the efficacy of surgery or injections. Exercise was the most frequently investigated treatment; no RTS data were reported for any exercise intervention. There was a reduction in pain and disability reported after all treatments.ConclusionsWhile several treatments for LBP in athletes improved pain and function, it was unclear what the most effective treatments were, and for whom. Exercise approaches generally reduced pain and improved function in athletes with LBP, but the effect on RTS is unknown. No conclusions regarding the value of manual therapy (massage, spinal manipulation) or biomechanical modifications alone could be drawn because of insufficient evidence. High-quality RCTs are urgently needed to determine the effect of commonly used interventions in treating LBP in athletes.
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| 5. |
- Wilson, F, et al.
(författare)
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Prevalence and risk factors for back pain in sports: a systematic review with meta-analysis
- 2021
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Ingår i: British journal of sports medicine. - : BMJ. - 1473-0480 .- 0306-3674. ; 55:11, s. 601-
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Tidskriftsartikel (refereegranskat)abstract
- We aimed to determine the prevalence of low back pain (LBP) in sport, and what risk factors were associated with LBP in athletes.DesignSystematic review with meta-analysis.Data sourcesLiterature searches from database inception to June 2019 in Medline, Embase, Cumulated Index to Nursing and Allied Health Literature (CINAHL), Web of Science and Scopus, supplemented by grey literature searching.Eligibility criteriaStudies evaluating prevalence of LBP in adult athletes across all sports.ResultsEighty-six studies were included (30 732, range 20–5958, participants), of which 45 were of ‘high’ quality. Definitions of LBP varied widely, and in 17 studies, no definition was provided. High-quality studies were pooled and the mean point prevalence across six studies was 42%; range 18%–80% (95% CI 27% to 58%, I2=97%). Lifetime prevalence across 13 studies was 63%; range 36%–88% (95% CI 51% to 74%, I2=99%). Twelve-month LBP prevalence from 22 studies was 51%; range 12%–94% (95% CI 41% to 61%, I2=98%). Comparison across sports was limited by participant numbers, study quality and methodologies, and varying LBP definitions. Risk factors for LBP included history of a previous episode with a pooled OR of 3.5; range 1.6–4.0 (95% CI 1.9 to 6.4). Statistically significant associations were reported for high training volume, periods of load increase and years of exposure to the sport.ConclusionLBP in sport is common but estimates vary. Current evidence is insufficient to identify which sports are at highest risk. A previous episode of LBP, high training volume, periods of load increase and years of exposure are common risk factors.
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