1. |
- Kehoe, Laura, et al.
(författare)
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Make EU trade with Brazil sustainable
- 2019
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 364:6438, s. 341-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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2. |
- Loisel, Julie, et al.
(författare)
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A database and synthesis of northern peatland soil properties and Holocene carbon and nitrogen accumulation
- 2014
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Ingår i: The Holocene. - : SAGE Publications. - 0959-6836 .- 1477-0911. ; 24:9, s. 1028-1042
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Tidskriftsartikel (refereegranskat)abstract
- Here, we present results from the most comprehensive compilation of Holocene peat soil properties with associated carbon and nitrogen accumulation rates for northern peatlands. Our database consists of 268 peat cores from 215 sites located north of 45 degrees N. It encompasses regions within which peat carbon data have only recently become available, such as the West Siberia Lowlands, the Hudson Bay Lowlands, Kamchatka in Far East Russia, and the Tibetan Plateau. For all northern peatlands, carbon content in organic matter was estimated at 42 +/- 3% (standard deviation) for Sphagnum peat, 51 +/- 2% for non-Sphagnum peat, and at 49 +/- 2% overall. Dry bulk density averaged 0.12 +/- 0.07 g/cm(3), organic matter bulk density averaged 0.11 +/- 0.05 g/cm(3), and total carbon content in peat averaged 47 +/- 6%. In general, large differences were found between Sphagnum and non-Sphagnum peat types in terms of peat properties. Time-weighted peat carbon accumulation rates averaged 23 +/- 2 (standard error of mean) g C/m(2)/yr during the Holocene on the basis of 151 peat cores from 127 sites, with the highest rates of carbon accumulation (25-28 g C/m(2)/yr) recorded during the early Holocene when the climate was warmer than the present. Furthermore, we estimate the northern peatland carbon and nitrogen pools at 436 and 10 gigatons, respectively. The database is publicly available at https://peatlands.lehigh.edu.
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3. |
- Van Hemelrijck, Mieke, et al.
(författare)
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Reasons for Discontinuing Active Surveillance : Assessment of 21 Centres in 12 Countries in the Movember GAP3 Consortium
- 2019
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Ingår i: European Urology. - : Elsevier BV. - 0302-2838. ; 75:3, s. 523-531
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Tidskriftsartikel (refereegranskat)abstract
- Background: Careful assessment of the reasons for discontinuation of active surveillance (AS) is required for men with prostate cancer (PCa). Objective: Using Movember's Global Action Plan Prostate Cancer Active Surveillance initiative (GAP3) database, we report on reasons for AS discontinuation. Design, setting, and participants: We compared data from 10 296 men on AS from 21 centres across 12 countries. Outcome measurements and statistical analysis: Cumulative incidence methods were used to estimate the cumulative incidence rates of AS discontinuation. Results and limitations: During 5-yr follow-up, 27.5% (95% confidence interval [CI]: 26.4–28.6%) men showed signs of disease progression, 12.8% (95% CI: 12.0–13.6%) converted to active treatment without evidence of progression, 1.7% (95% CI: 1.5–2.0%) continued to watchful waiting, and 1.7% (95% CI: 1.4–2.1%) died from other causes. Of the 7049 men who remained on AS, 2339 had follow-up for >5 yr, 4561 had follow-up for <5 yr, and 149 were lost to follow-up. Cumulative incidence of progression was 27.5% (95% CI: 26.4–28.6%) at 5 yr and 38.2% (95% CI: 36.7–39.9%) at 10 yr. A limitation is that not all centres were included due to limited information on the reason for discontinuation and limited follow-up. Conclusions: Our descriptive analyses of current AS practices worldwide showed that 43.6% of men drop out of AS during 5-yr follow-up, mainly due to signs of disease progression. Improvements in selection tools for AS are thus needed to correctly allocate men with PCa to AS, which will also reduce discontinuation due to conversion to active treatment without evidence of disease progression. Patient summary: Our assessment of a worldwide database of men with prostate cancer (PCa) on active surveillance (AS) shows that 43.6% drop out of AS within 5 yr, mainly due to signs of disease progression. Better tools are needed to select and monitor men with PCa as part of AS.
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4. |
- Albert, A., et al.
(författare)
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Discovery of Gamma Rays from the Quiescent Sun with HAWC
- 2023
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 131:5
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Tidskriftsartikel (refereegranskat)abstract
- We report the first detection of a TeV 7-ray flux from the solar disk (6.3a), based on 6.1 years of data from the High Altitude Water Cherenkov (HAWC) observatory. The 0.5-2.6 TeV spectrum is well fit by a power law, dN/dE=A(E/1 TeV)-7, with A = (1.6 & PLUSMN; 0.3) x 10-12 TeV-1 cm-2 s-1 and 7 = 3.62 & PLUSMN; 0.14. The flux shows a strong indication of anticorrelation with solar activity. These results extend the bright, hard GeV emission from the disk observed with Fermi-LAT, seemingly due to hadronic Galactic cosmic rays showering on nuclei in the solar atmosphere. However, current theoretical models are unable to explain the details of how solar magnetic fields shape these interactions. HAWC's TeV detection thus deepens the mysteries of the solar-disk emission.
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5. |
- Blanco, Carlos, et al.
(författare)
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Star-forming galaxies provide a larger contribution to the isotropic gamma-ray background than misaligned active galactic nuclei
- 2023
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Ingår i: Journal of Cosmology and Astroparticle Physics. - : IOP Publishing. - 1475-7516. ; 2023:2
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Tidskriftsartikel (refereegranskat)abstract
- The total extragalactic γ-ray flux provides a powerful probe into the origin and evolution of the highest energy processes in our universe. An important component of this emission is the isotropic γ-ray background (IGRB), composed of sources that cannot be individually resolved by current experiments. Previous studies have determined that the IGRB can be dominated by either misaligned active galactic nuclei (mAGN) or star-forming galaxies (SFGs). However, these analyses are limited, because they have utilized binary source classifications and examined only one source class at a time. We perform the first combined joint-likelihood analysis that simultaneously correlates the γ-ray luminosity of extragalactic objects with both star-formation and mAGN activity. We find that SFGs produce 48+33-20% of the total IGRB at 1 GeV and 56+40-23% of the total IGRB at 10 GeV. The contribution of mAGN is more uncertain, but can also be significant. Future work to quantify the radio and infrared properties of nearby galaxies could significantly improve these constraints.
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6. |
- Blanco, Carlos, 1992-, et al.
(författare)
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Where are the Cascades from Blazar Jets? An Emerging Tension in the γ-ray sky
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Blazars are among the most powerful accelerators and are expected to produce a bright TeV γ-ray flux. However, TeV γ-rays are attenuated by interactions with intergalactic radiation before reaching Earth. These interactions produce cascades that transfer TeV power into the GeV band, powering both extended halos around bright sources and a large contribution to the isotropic γ-ray background (IGRB). Using conservative blazar models and recent IGRB measurements, we rule out scenarios where blazars effectively transfer their multi-TeV power into GeV γ-rays. Three possible solutions include: (1) strong spectral cuts on bright blazars, which are increasingly in tension with local blazar data, (2) collective plasma effects that can prevent the development of blazar cascades, the effectiveness of which is debated, (3) an increase in the γ-ray opacity from axion-like particles.
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7. |
- Boen, Rune, et al.
(författare)
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Beyond the global brain differences : intraindividual variability differences in 1q21.1 distal and 15q11.2 bp1-bp2 deletion carriers
- 2024
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Ingår i: Biological Psychiatry. - 0006-3223 .- 1873-2402. ; 95:2, s. 147-160
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Tidskriftsartikel (refereegranskat)abstract
- Background: Carriers of the 1q21.1 distal and 15q11.2 BP1-BP2 copy number variants exhibit regional and global brain differences compared with noncarriers. However, interpreting regional differences is challenging if a global difference drives the regional brain differences. Intraindividual variability measures can be used to test for regional differences beyond global differences in brain structure.Methods: Magnetic resonance imaging data were used to obtain regional brain values for 1q21.1 distal deletion (n = 30) and duplication (n = 27) and 15q11.2 BP1-BP2 deletion (n = 170) and duplication (n = 243) carriers and matched noncarriers (n = 2350). Regional intra-deviation scores, i.e., the standardized difference between an individual's regional difference and global difference, were used to test for regional differences that diverge from the global difference.Results: For the 1q21.1 distal deletion carriers, cortical surface area for regions in the medial visual cortex, posterior cingulate, and temporal pole differed less and regions in the prefrontal and superior temporal cortex differed more than the global difference in cortical surface area. For the 15q11.2 BP1-BP2 deletion carriers, cortical thickness in regions in the medial visual cortex, auditory cortex, and temporal pole differed less and the prefrontal and somatosensory cortex differed more than the global difference in cortical thickness.Conclusions: We find evidence for regional effects beyond differences in global brain measures in 1q21.1 distal and 15q11.2 BP1-BP2 copy number variants. The results provide new insight into brain profiling of the 1q21.1 distal and 15q11.2 BP1-BP2 copy number variants, with the potential to increase understanding of the mechanisms involved in altered neurodevelopment.
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8. |
- Cholis, Ilias, et al.
(författare)
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Antideuterons and antihelium nuclei from annihilating dark matter
- 2020
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Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 102:10
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies of the cosmic-ray antiproton-to-proton ratio have identified an excess of similar to 10-20 GeV antiprotons relative to the predictions of standard astrophysical models. Intriguingly, the properties of this excess are consistent with the same range of dark matter models that can account for the long-standing excess of gamma-rays observed from the Galactic Center. Such dark matter candidates can also produce significant fluxes of antideuterium and antihelium nuclei. Here we study the production and transport of such particles, both from astrophysical processes as well as from dark matter annihilation. Importantly, in the case of AMS-02, we find that Alfvenic reacceleration (i.e., diffusion in momentum space) can boost the expected number of (d) over bar and 3 (He) over bar events from annihilating dark matter by an order of magnitude or more. For relatively large values of the Alfven speed, and for dark matter candidates that are capable of producing the antiproton and gamma-ray excesses, we expect annihilations to produce a few antideuteron events and about one antihelium event in 6 yr of AMS-02 data. This is particularly interesting in light of recent reports from the AMS-02 Collaboration describing the detection of a number of antihelium candidate events.
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9. |
- Cholis, Ilias, et al.
(författare)
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Constraining the charge-sign and rigidity-dependence of solar modulation
- 2022
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Ingår i: Journal of Cosmology and Astroparticle Physics. - : IOP Publishing. - 1475-7516. ; :10
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Tidskriftsartikel (refereegranskat)abstract
- Our ability to identify the sources of cosmic rays and understand how these particles propagate through the interstellar medium is hindered by the combined effects of the solar wind and its embedded magnetic field, collectively known as solar modulation. In this paper, we build upon our previous work to model and constrain the effects of solar modulation on the cosmic-ray spectrum, using data from AMS-02 and BESS Polar II collected between 2007 and 2012, during which the heliospheric magnetic field was in a state of negative polarity. Our model uses measurements of the heliospheric magnetic field and the tilt angle of the heliospheric current sheet to accurately predict the effects of solar modulation as a function of time, charge, and rigidity. By incorporating data from a period of negative polarity, we have been able to robustly observe and constrain the charge-dependent effects of solar modulation.
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10. |
- Crnogorčević, Milena, et al.
(författare)
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Strong constraints on dark matter annihilation in Ursa Major III/UNIONS 1
- 2024
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Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 109:8
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Tidskriftsartikel (refereegranskat)abstract
- Very recent work has identified a new satellite galaxy, Ursa Major III/UNIONS I, which is the faintest such system ever observed. Dynamical considerations indicate that if the system is in equilibrium, it is likely to be highly dark matter dominated. This, in combination with its proximity, predicts that it may be the preeminent dwarf spheroidal galaxy target for dark matter indirect detection searches. We utilize 15 years of Fermi-LAT data to search for ?-ray emission from Ursa Major III. Finding no excess, we set strong constraints on dark matter annihilation. Intriguingly, if the high J-factor of Ursa Major III is confirmed, standard thermal dark matter annihilation to ?¯? final states would be ruled out for dark matter masses up to 4 TeV. The discovery of Ursa Major III, combined with recent tentative measurements of other high J-factor systems, suggests the exciting possibility that near-future data could produce transformative constraints on thermal dark matter.
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