| 1. |
- Murari, A., et al.
(författare)
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A control oriented strategy of disruption prediction to avoid the configuration collapse of tokamak reactors
- 2024
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Ingår i: Nature Communications. - 2041-1723 .- 2041-1723. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- The objective of thermonuclear fusion consists of producing electricity from the coalescence of light nuclei in high temperature plasmas. The most promising route to fusion envisages the confinement of such plasmas with magnetic fields, whose most studied configuration is the tokamak. Disruptions are catastrophic collapses affecting all tokamak devices and one of the main potential showstoppers on the route to a commercial reactor. In this work we report how, deploying innovative analysis methods on thousands of JET experiments covering the isotopic compositions from hydrogen to full tritium and including the major D-T campaign, the nature of the various forms of collapse is investigated in all phases of the discharges. An original approach to proximity detection has been developed, which allows determining both the probability of and the time interval remaining before an incoming disruption, with adaptive, from scratch, real time compatible techniques. The results indicate that physics based prediction and control tools can be developed, to deploy realistic strategies of disruption avoidance and prevention, meeting the requirements of the next generation of devices.
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| 6. |
- Tinetti, Giovanna, et al.
(författare)
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The EChO science case
- 2015
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Ingår i: Experimental astronomy. - : Springer Science and Business Media LLC. - 0922-6435 .- 1572-9508. ; 40:2-3, s. 329-391
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Tidskriftsartikel (refereegranskat)abstract
- The discovery of almost two thousand exoplanets has revealed an unexpectedly diverse planet population. We see gas giants in few-day orbits, whole multi-planet systems within the orbit of Mercury, and new populations of planets with masses between that of the Earth and Neptune-all unknown in the Solar System. Observations to date have shown that our Solar System is certainly not representative of the general population of planets in our Milky Way. The key science questions that urgently need addressing are therefore: What are exoplanets made of? Why are planets as they are? How do planetary systems work and what causes the exceptional diversity observed as compared to the Solar System? The EChO (Exoplanet Characterisation Observatory) space mission was conceived to take up the challenge to explain this diversity in terms of formation, evolution, internal structure and planet and atmospheric composition. This requires in-depth spectroscopic knowledge of the atmospheres of a large and well-defined planet sample for which precise physical, chemical and dynamical information can be obtained. In order to fulfil this ambitious scientific program, EChO was designed as a dedicated survey mission for transit and eclipse spectroscopy capable of observing a large, diverse and well-defined planet sample within its 4-year mission lifetime. The transit and eclipse spectroscopy method, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allows us to measure atmospheric signals from the planet at levels of at least 10(-4) relative to the star. This can only be achieved in conjunction with a carefully designed stable payload and satellite platform. It is also necessary to provide broad instantaneous wavelength coverage to detect as many molecular species as possible, to probe the thermal structure of the planetary atmospheres and to correct for the contaminating effects of the stellar photosphere. This requires wavelength coverage of at least 0.55 to 11 mu m with a goal of covering from 0.4 to 16 mu m. Only modest spectral resolving power is needed, with R similar to 300 for wavelengths less than 5 mu m and R similar to 30 for wavelengths greater than this. The transit spectroscopy technique means that no spatial resolution is required. A telescope collecting area of about 1 m(2) is sufficiently large to achieve the necessary spectro-photometric precision: for the Phase A study a 1.13 m(2) telescope, diffraction limited at 3 mu m has been adopted. Placing the satellite at L2 provides a cold and stable thermal environment as well as a large field of regard to allow efficient time-critical observation of targets randomly distributed over the sky. EChO has been conceived to achieve a single goal: exoplanet spectroscopy. The spectral coverage and signal-to-noise to be achieved by EChO, thanks to its high stability and dedicated design, would be a game changer by allowing atmospheric composition to be measured with unparalleled exactness: at least a factor 10 more precise and a factor 10 to 1000 more accurate than current observations. This would enable the detection of molecular abundances three orders of magnitude lower than currently possible and a fourfold increase from the handful of molecules detected to date. Combining these data with estimates of planetary bulk compositions from accurate measurements of their radii and masses would allow degeneracies associated with planetary interior modelling to be broken, giving unique insight into the interior structure and elemental abundances of these alien worlds. EChO would allow scientists to study exoplanets both as a population and as individuals. The mission can target super-Earths, Neptune-like, and Jupiter-like planets, in the very hot to temperate zones (planet temperatures of 300-3000 K) of F to M-type host stars. The EChO core science would be delivered by a three-tier survey. The EChO Chemical Census: This is a broad survey of a few-hundred exoplanets, which allows us to explore the spectroscopic and chemical diversity of the exoplanet population as a whole. The EChO Origin: This is a deep survey of a subsample of tens of exoplanets for which significantly higher signal to noise and spectral resolution spectra can be obtained to explain the origin of the exoplanet diversity (such as formation mechanisms, chemical processes, atmospheric escape). The EChO Rosetta Stones: This is an ultra-high accuracy survey targeting a subsample of select exoplanets. These will be the bright "benchmark" cases for which a large number of measurements would be taken to explore temporal variations, and to obtain two and three dimensional spatial information on the atmospheric conditions through eclipse-mapping techniques. If EChO were launched today, the exoplanets currently observed are sufficient to provide a large and diverse sample. The Chemical Census survey would consist of > 160 exoplanets with a range of planetary sizes, temperatures, orbital parameters and stellar host properties. Additionally, over the next 10 years, several new ground- and space-based transit photometric surveys and missions will come on-line (e.g. NGTS, CHEOPS, TESS, PLATO), which will specifically focus on finding bright, nearby systems. The current rapid rate of discovery would allow the target list to be further optimised in the years prior to EChO's launch and enable the atmospheric characterisation of hundreds of planets.
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| 11. |
- Leleu, A., et al.
(författare)
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Six transiting planets and a chain of Laplace resonances in TOI-178
- 2021
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 649
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Tidskriftsartikel (refereegranskat)abstract
- Determining the architecture of multi-planetary systems is one of the cornerstones of understanding planet formation and evolution. Resonant systems are especially important as the fragility of their orbital configuration ensures that no significant scattering or collisional event has taken place since the earliest formation phase when the parent protoplanetary disc was still present. In this context, TOI-178 has been the subject of particular attention since the first TESS observations hinted at the possible presence of a near 2:3:3 resonant chain. Here we report the results of observations from CHEOPS, ESPRESSO, NGTS, and SPECULOOS with the aim of deciphering the peculiar orbital architecture of the system. We show that TOI-178 harbours at least six planets in the super-Earth to mini-Neptune regimes, with radii ranging from 1.152 to 2.87 Earth radii and periods of 1.91, 3.24, 6.56, 9.96, 15.23, and 20.71 days. All planets but the innermost one form a 2:4:6:9:12 chain of Laplace resonances, and the planetary densities show important variations from planet to planet, jumping from 1.02 to 0.177 times the Earth's density between planets c and d. Using Bayesian interior structure retrieval models, we show that the amount of gas in the planets does not vary in a monotonous way, contrary to what one would expect from simple formation and evolution models and unlike other known systems in a chain of Laplace resonances. The brightness of TOI-178 (H = 8.76 mag, J = 9.37 mag, V = 11.95 mag) allows for a precise characterisation of its orbital architecture as well as of the physical nature of the six presently known transiting planets it harbours. The peculiar orbital configuration and the diversity in average density among the planets in the system will enable the study of interior planetary structures and atmospheric evolution, providing important clues on the formation of super-Earths and mini-Neptunes. -0.070 -0.13 -0.23 -0.061 +0.073 +0.14 +0.28 +0.055
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| 16. |
- Hall, CL, et al.
(författare)
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Investigating a therapist-guided, parent-assisted remote digital behavioural intervention for tics in children and adolescents-'Online Remote Behavioural Intervention for Tics' (ORBIT) trial: protocol of an internal pilot study and single-blind randomised controlled trial
- 2019
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Ingår i: BMJ open. - : BMJ. - 2044-6055. ; 9:1, s. e027583-
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Tidskriftsartikel (refereegranskat)abstract
- Tourette syndrome and chronic tic disorder are common, disabling childhood-onset conditions. Guidelines recommend that behavioural therapy should be offered as first-line treatment for children with tics. However, there are very few trained behaviour therapists for tics and many patients cannot access appropriate care. This trial investigates whether an internet-delivered intervention for tics can reduce severity of symptoms.Methods and analysisThis parallel-group, single-blind, randomised controlled superiority trial with an internal pilot will recruit children and young people (aged 9–17 years) with tic disorders. Participants will be randomised to receive 10 weeks of either online, remotely delivered, therapist-supported exposure response prevention behavioural therapy for tics, or online, remotely delivered, therapist-supported education about tics and co-occurring conditions. Participants will be followed up mid-treatment, and 3, 6, 12 and 18 months post randomisation.The primary outcome is reduction in tic severity as measured on the Yale Global Tic Severity Scale total tic severity score. Secondary outcomes include a cost-effectiveness analysis and estimate of the longer-term impact on patient outcomes and healthcare services. An integrated process evaluation will analyse quantitative and qualitative data in order to fully explore the implementation of the intervention and identify barriers and facilitators to implementation. The trial is funded by the National Institute of Health Research (NIHR), Health Technology Assessment (16/19/02).Ethics and disseminationThe findings from the study will inform clinicians, healthcare providers and policy makers about the clinical and cost-effectiveness of an internet delivered treatment for children and young people with tics. The results will be submitted for publication in peer-reviewed journals. The study has received ethical approval from North West Greater Manchester Research Ethics Committee (ref.: 18/NW/0079).Trial registration numbersISRCTN70758207andNCT03483493; Pre-results.
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| 19. |
- Anelli, V. W., et al.
(författare)
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RecSys 2021 challenge workshop : Fairness-aware engagement prediction at scale on Twiter's Home Timeline
- 2021
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Ingår i: RecSys 2021 - 15th ACM Conference on Recommender Systems. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450384582 ; , s. 819-824
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Konferensbidrag (refereegranskat)abstract
- The workshop features presentations of accepted contributions to the RecSys Challenge 2021, organized by Politecnico di Bari, ETH Zürich, Jönköping University, and the data set is provided by Twitter. The challenge focuses on a real-world task of tweet engagement prediction in a dynamic environment. For 2021, the challenge considers four different engagement types: Likes, Retweet, Quote, and replies. This year's challenge brings the problem even closer to Twitter's real recommender systems by introducing latency constraints. We also increases the data size to encourage novel methods. Also, the data density is increased in terms of the graph where users are considered to be nodes and interactions as edges. The goal is twofold: to predict the probability of different engagement types of a target user for a set of Tweets based on heterogeneous input data while providing fair recommendations. In fact, multi-goal optimization considering accuracy and fairness is particularly challenging. However, we believed that the recommendation community was nowadays mature enough to face the challenge of providing accurate and, at the same time, fair recommendations. To this end, Twitter has released a public dataset of close to 1 billion data points, > 40 million each day over 28 days. Week 1-3 will be used for training and week 4 for evaluation and testing. Each datapoint contains the tweet along with engagement features, user features, and tweet features. A peculiarity of this challenge is related to keeping the dataset updated with the platform: if a user deletes a Tweet, or their data from Twitter, the dataset is promptly updated. Moreover, each change in the dataset implied new evaluations of all submissions and the update of the leaderboard metrics. The challenge was well received with 578 registered users, and 386 submissions.
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| 28. |
- Ernst, R. E., et al.
(författare)
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Long-lived connection between southern Siberia and northern Laurentia in the Proterozoic
- 2016
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Ingår i: Nature Geoscience. - : Springer Science and Business Media LLC. - 1752-0894 .- 1752-0908. ; 9:6, s. 464-469
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Tidskriftsartikel (refereegranskat)abstract
- Precambrian supercontinents Nuna-Columbia (1.7 to 1.3 billion years ago) and Rodinia (1.1 to 0.7 billion years ago) have been proposed. However, the arrangements of crustal blocks within these supercontinents are poorly known. Huge, dominantly basaltic magmatic outpourings and intrusions, covering up to millions of square kilometres, termed Large Igneous Provinces, typically accompany (super) continent breakup, or attempted breakup and offer an important tool for reconstructing supercontinents. Here we focus on the Large Igneous Province record for Siberia and Laurentia, whose relative position in Nuna-Columbia and Rodinia reconstructions is highly controversial. We present precise geochronology - nine U-Pb and six Ar-Ar ages - on dolerite dykes and sills, along with existing dates from the literature, that constrain the timing of emplacement of Large Igneous Province magmatism in southern Siberia and northern Laurentia between 1,900 and 720 million years ago. We identify four robust age matches between the continents 1,870, 1,750, 1,350 and 720 million years ago, as well as several additional approximate age correlations that indicate southern Siberia and northern Laurentia were probably near neighbours for this 1.2-billion-year interval. Our reconstructions provide a framework for evaluating the shared geological, tectonic and metallogenic histories of these continental blocks.
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| 29. |
- Ernst, R. E., et al.
(författare)
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The 1501 Ma Kuonamka Large Igneous Province of northern Siberia : U-Pb geochronology, geochemistry, and links with coeval magmatism on other crustal blocks
- 2016
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Ingår i: Russian Geology and Geophysics. - : GeoScienceWorld. - 1068-7971. ; 57:5, s. 653-671
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Tidskriftsartikel (refereegranskat)abstract
- A new large igneous province (LIP), the 1501 ± 3 Ma Kuonamka LIP, extends across 700 km of northern Siberia and is linked with coeval dikes and sills in the formerly attached Sao Francisco craton (SFC)-Congo craton to yield a short-duration event 2000 km across. The age of the Kuonamka LIP can be summarized as 1501 ± 3 Ma (95% confidence), based on 7 U-Pb ID-TIMS ages (6 new herein) from dolerite dikes and sills across the Anabar shield and within western Riphean cover rocks for a distance of 270 km. An additional sill yielded a SIMS (CAMECA) age of 1483 ± 17 Ma and sill in the Olenek uplift several hundred kilometers farther east, a previous SIMS (SHRIMP) age of ca. 1473 Ma was obtained on a sill; both SIMS ages are within the age uncertainty of the ID-TIMS ages. Geochemical data indicate a tholeiitic basalt composition with low MgO (4-7 wt%) within-plate character based on trace element classification diagrams and source between E-MORB and OIB with only minor contamination from crust or metasomatized lithospheric mantle. Two subgroups are distinguished: Group 1 has gently sloping LREE ((La/Sm)PM = 1.9) and HREE ((Gd/Yb)PM = 1.8) patterns, slightly negative Sr and moderate TiO2 (2.2 wt%), and Group 2 has steeper LREE ((La/Sm)PM = 2.3) and HREE ((Gd/Yb)PM = 2.3), strong negative Sr anomaly, is higher in TiO2 (2.7 wt%), and is transitional from tholeiitic to weakly alkaline in composition. The slight differences in REE slopes are consistent with Group 2 on average melting at deeper levels. Proposed reconstructions of the Kuonamka LIP with 1500 Ma magmatism of the SFC-Congo craton are supported by a geochemical comparison. Specifically, the chemistry of the Chapada Diamantina and Curaga dikes of the SFC can be linked to that of Groups 1 and 2, respectively, of the Kuonamka LIP and are consistent with a common mantle source between EMORB and OIB and subsequent differentiation history. However, the coeval Humpata sills and dikes of the Angola block of the Congo craton represent a different magma batch.
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| 33. |
- Hollis, Chris, et al.
(författare)
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Online remote behavioural intervention for tics in 9- to 17-year-olds : the ORBIT RCT with embedded process and economic evaluation
- 2023
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Ingår i: Health Technology Assessment. - 1366-5278. ; 27:18, s. 1-120
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Behavioural therapy for tics is difficult to access, and little is known about its effectiveness when delivered online.OBJECTIVE: To investigate the clinical and cost-effectiveness of an online-delivered, therapist- and parent-supported therapy for young people with tic disorders.DESIGN: Single-blind, parallel-group, randomised controlled trial, with 3-month (primary end point) and 6-month post-randomisation follow-up. Participants were individually randomised (1 : 1), using on online system, with block randomisations, stratified by site. Naturalistic follow-up was conducted at 12 and 18 months post-randomisation when participants were free to access non-trial interventions. A subset of participants participated in a process evaluation.SETTING: Two hospitals (London and Nottingham) in England also accepting referrals from patient identification centres and online self-referrals.PARTICIPANTS: Children aged 9-17 years (1) with Tourette syndrome or chronic tic disorder, (2) with a Yale Global Tic Severity Scale-total tic severity score of 15 or more (or > 10 with only motor or vocal tics) and (3) having not received behavioural therapy for tics in the past 12 months or started/stopped medication for tics within the past 2 months.INTERVENTIONS: Either 10 weeks of online, remotely delivered, therapist-supported exposure and response prevention therapy (intervention group) or online psychoeducation (control).OUTCOME: Primary outcome: Yale Global Tic Severity Scale-total tic severity score 3 months post-randomisation; analysis done in all randomised patients for whom data were available. Secondary outcomes included low mood, anxiety, treatment satisfaction and health resource use. Quality-adjusted life-years are derived from parent-completed quality-of-life measures. All trial staff, statisticians and the chief investigator were masked to group allocation.RESULTS: Two hundred and twenty-four participants were randomised to the intervention (n = 112) or control (n = 112) group. Participants were mostly male (n = 177; 79%), with a mean age of 12 years. At 3 months the estimated mean difference in Yale Global Tic Severity Scale-total tic severity score between the groups adjusted for baseline and site was -2.29 points (95% confidence interval -3.86 to -0.71) in favour of therapy (effect size -0.31, 95% confidence interval -0.52 to -0.10). This effect was sustained throughout to the final follow-up at 18 months (-2.01 points, 95% confidence interval -3.86 to -0.15; effect size -0.27, 95% confidence interval -0.52 to -0.02). At 18 months the mean incremental cost per participant of the intervention compared to the control was £662 (95% confidence interval -£59 to £1384), with a mean incremental quality-adjusted life-year of 0.040 (95% confidence interval -0.004 to 0.083) per participant. The mean incremental cost per quality-adjusted life-year gained was £16,708. The intervention was acceptable and delivered with high fidelity. Parental engagement predicted child engagement and more positive clinical outcomes.HARMS: Two serious, unrelated adverse events occurred in the control group.LIMITATIONS: We cannot separate the effects of digital online delivery and the therapy itself. The sample was predominately white and British, limiting generalisability. The design did not compare to face-to-face services.CONCLUSION: Online, therapist-supported behavioural therapy for young people with tic disorders is clinically and cost-effective in reducing tics, with durable benefits extending up to 18 months.FUTURE WORK: Future work should compare online to face-to-face therapy and explore how to embed the intervention in clinical practice.TRIAL REGISTRATION: This trial is registered as ISRCTN70758207; ClinicalTrials.gov (NCT03483493). The trial is now complete.FUNDING: This project was funded by the National Institute for Health and Care Research (NIHR) Health and Technology Assessment programme (project number 16/19/02) and will be published in full in Health and Technology Assessment; Vol. 27, No. 18. See the NIHR Journals Library website for further project information.
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| 34. |
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| 35. |
- Kageyama, Masa, et al.
(författare)
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A multi-model CMIP6-PMIP4 study of Arctic sea ice at 127 ka : sea ice data compilation and model differences
- 2021
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Ingår i: Climate of the Past. - : Copernicus GmbH. - 1814-9324 .- 1814-9332. ; 17:1, s. 37-62
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Tidskriftsartikel (refereegranskat)abstract
- The Last Interglacial period (LIG) is a period with increased summer insolation at high northern latitudes, which results in strong changes in the terrestrial and marine cryosphere. Understanding the mechanisms for this response via climate modelling and comparing the models' representation of climate reconstructions is one of the objectives set up by the Paleoclimate Modelling Intercomparison Project for its contribution to the sixth phase of the Coupled Model Intercomparison Project. Here we analyse the results from 16 climate models in terms of Arctic sea ice. The multi-model mean reduction in minimum sea ice area from the pre industrial period (PI) to the LIG reaches 50 % (multi-model mean LIG area is 3.20×106 km2, compared to 6.46×106 km2 for the PI). On the other hand, there is little change for the maximum sea ice area (which is 15–16×106 km2 for both the PI and the LIG. To evaluate the model results we synthesise LIG sea ice data from marine cores collected in the Arctic Ocean, Nordic Seas and northern North Atlantic. The reconstructions for the northern North Atlantic show year-round ice-free conditions, and most models yield results in agreement with these reconstructions. Model–data disagreement appear for the sites in the Nordic Seas close to Greenland and at the edge of the Arctic Ocean. The northernmost site with good chronology, for which a sea ice concentration larger than 75 % is reconstructed even in summer, discriminates those models which simulate too little sea ice. However, the remaining models appear to simulate too much sea ice over the two sites south of the northernmost one, for which the reconstructed sea ice cover is seasonal. Hence models either underestimate or overestimate sea ice cover for the LIG, and their bias does not appear to be related to their bias for the pre-industrial period. Drivers for the inter-model differences are different phasing of the up and down short-wave anomalies over the Arctic Ocean, which are associated with differences in model albedo; possible cloud property differences, in terms of optical depth; and LIG ocean circulation changes which occur for some, but not all, LIG simulations. Finally, we note that inter-comparisons between the LIG simulations and simulations for future climate with moderate (1 % yr−1) CO2 increase show a relationship between LIG sea ice and sea ice simulated under CO2 increase around the years of doubling CO2. The LIG may therefore yield insight into likely 21st century Arctic sea ice changes using these LIG simulations.
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| 36. |
- Knox, Sara H., et al.
(författare)
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FLUXNET-CH4 Synthesis Activity : Objectives, Observations, and Future Directions
- 2019
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Ingår i: Bulletin of The American Meteorological Society - (BAMS). - 0003-0007 .- 1520-0477. ; 100:12, s. 2607-2632
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes the formation of, and initial results for, a new FLUXNET coordination network for ecosystem-scale methane (CH4) measurements at 60 sites globally, organized by the Global Carbon Project in partnership with other initiatives and regional flux tower networks. The objectives of the effort are presented along with an overview of the coverage of eddy covariance (EC) CH4 flux measurements globally, initial results comparing CH4 fluxes across the sites, and future research directions and needs. Annual estimates of net CH4 fluxes across sites ranged from -0.2 +/- 0.02 g C m(-2) yr(-1) for an upland forest site to 114.9 +/- 13.4 g C m(-2) yr(-1) for an estuarine freshwater marsh, with fluxes exceeding 40 g C m(-2) yr(-1) at multiple sites. Average annual soil and air temperatures were found to be the strongest predictor of annual CH4 flux across wetland sites globally. Water table position was positively correlated with annual CH4 emissions, although only for wetland sites that were not consistently inundated throughout the year. The ratio of annual CH4 fluxes to ecosystem respiration increased significantly with mean site temperature. Uncertainties in annual CH4 estimates due to gap-filling and random errors were on average +/- 1.6 g C m(-2) yr(-1) at 95% confidence, with the relative error decreasing exponentially with increasing flux magnitude across sites. Through the analysis and synthesis of a growing EC CH4 flux database, the controls on ecosystem CH4 fluxes can be better understood, used to inform and validate Earth system models, and reconcile differences between land surface model- and atmospheric-based estimates of CH4 emissions.
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| 37. |
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| 38. |
- Rubertsson, Sten, et al.
(författare)
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The Study Protocol for the LINC (LUCAS in Cardiac Arrest) Study : a study comparing conventional adult out-of-hospital cardiopulmonary resuscitation with a concept with mechanical chest compressions and simultaneous defibrillation
- 2013
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Ingår i: Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine. - : BioMed Central Ltd.. - 1757-7241. ; 21:5
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Tidskriftsartikel (refereegranskat)abstract
- Background The LUCAS™ device delivers mechanical chest compressions that have been shown in experimental studies to improve perfusion pressures to the brain and heart as well as augmenting cerebral blood flow and end tidal CO2, compared with results from standard manual cardiopulmonary resuscitation (CPR). Two randomised pilot studies in out-of-hospital cardiac arrest patients have not shown improved outcome when compared with manual CPR. There remains evidence from small case series that the device can be potentially beneficial compared with manual chest compressions in specific situations. This multicentre study is designed to evaluate the efficacy and safety of mechanical chest compressions with the LUCAS™ device whilst allowing defibrillation during on-going CPR, and comparing the results with those of conventional resuscitation. Methods/design This article describes the design and protocol of the LINC-study which is a randomised controlled multicentre study of 2500 out-of-hospital cardiac arrest patients. The study has been registered at ClinicalTrials.gov (http://clinicaltrials.gov/ct2/show/NCT00609778?term=LINC&rank=1 webcite). Results Primary endpoint is four-hour survival after successful restoration of spontaneous circulation. The safety aspect is being evaluated by post mortem examinations in 300 patients that may reflect injuries from CPR. Conclusion This large multicentre study will contribute to the evaluation of mechanical chest compression in CPR and specifically to the efficacy and safety of the LUCAS™ device when used in association with defibrillation during on-going CPR.
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| 39. |
- Smith, Madison M., et al.
(författare)
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Thin and transient meltwater layers and false bottoms in the Arctic sea ice pack—Recent insights on these historically overlooked features
- 2023
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Ingår i: Elementa: Science of the Anthropocene. - 2325-1026. ; 11:1
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Forskningsöversikt (refereegranskat)abstract
- The rapid melt of snow and sea ice during the Arctic summer provides a significant source of low-salinity meltwater to the surface ocean on the local scale. The accumulation of this meltwater on, under, and around sea ice floes can result in relatively thin meltwater layers in the upper ocean. Due to the small-scale nature of these upper-ocean features, typically on the order of 1 m thick or less, they are rarely detected by standard methods, but are nevertheless pervasive and critically important in Arctic summer. Observations during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition in summer 2020 focused on the evolution of such layers and made significant advancements in understanding their role in the coupled Arctic system. Here we provide a review of thin meltwater layers in the Arctic, with emphasis on the new findings from MOSAiC. Both prior and recent observational datasets indicate an intermittent yet longlasting (weeks to months) meltwater layer in the upper ocean on the order of 0.1 m to 1.0 m in thickness, with a large spatial range. The presence of meltwater layers impacts the physical system by reducing bottom ice melt and allowing new ice formation via false bottom growth. Collectively, the meltwater layer and false bottoms reduce atmosphere-ocean exchanges of momentum, energy, and material.The impacts on the coupled Arctic system are far-reaching, including acting as a barrier for nutrient and gas exchange and impacting ecosystem diversity and productivity.
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| 40. |
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| 41. |
- Unat, Didem, et al.
(författare)
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Trends in Data Locality Abstractions for HPC Systems
- 2017
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Ingår i: IEEE Transactions on Parallel and Distributed Systems. - : IEEE Computer Society. - 1045-9219 .- 1558-2183. ; 28:10, s. 3007-3020
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Tidskriftsartikel (refereegranskat)abstract
- The cost of data movement has always been an important concern in high performance computing (HPC) systems. It has now become the dominant factor in terms of both energy consumption and performance. Support for expression of data locality has been explored in the past, but those efforts have had only modest success in being adopted in HPC applications for various reasons. them However, with the increasing complexity of the memory hierarchy and higher parallelism in emerging HPC systems, locality management has acquired a new urgency. Developers can no longer limit themselves to low-level solutions and ignore the potential for productivity and performance portability obtained by using locality abstractions. Fortunately, the trend emerging in recent literature on the topic alleviates many of the concerns that got in the way of their adoption by application developers. Data locality abstractions are available in the forms of libraries, data structures, languages and runtime systems; a common theme is increasing productivity without sacrificing performance. This paper examines these trends and identifies commonalities that can combine various locality concepts to develop a comprehensive approach to expressing and managing data locality on future large-scale high-performance computing systems.
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| 42. |
- Unat, D., et al.
(författare)
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Trends in Data Locality Abstractions for HPC Systems
- 2017
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Ingår i: IEEE Transactions on Parallel and Distributed Systems. - : Institute of Electrical and Electronics Engineers (IEEE). - 1558-2183 .- 1045-9219. ; 28:10, s. 3007-3020
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Tidskriftsartikel (refereegranskat)abstract
- The cost of data movement has always been an important concern in high performance computing (HPC) systems. It has now become the dominant factor in terms of both energy consumption and performance. Support for expression of data locality has been explored in the past, but those efforts have had only modest success in being adopted in HPC applications for various reasons. them However, with the increasing complexity of the memory hierarchy and higher parallelism in emerging HPC systems, locality management has acquired a new urgency. Developers can no longer limit themselves to low-level solutions and ignore the potential for productivity and performance portability obtained by using locality abstractions. Fortunately, the trend emerging in recent literature on the topic alleviates many of the concerns that got in the way of their adoption by application developers. Data locality abstractions are available in the forms of libraries, data structures, languages and runtime systems; a common theme is increasing productivity without sacrificing performance. This paper examines these trends and identifies commonalities that can combine various locality concepts to develop a comprehensive approach to expressing and managing data locality on future large-scale high-performance computing systems.
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| 43. |
- Wardrop, NA, et al.
(författare)
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Spatially disaggregated population estimates in the absence of national population and housing census data
- 2018
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 1091-6490. ; 115:14, s. 3529-3537
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Tidskriftsartikel (refereegranskat)abstract
- Population numbers at local levels are fundamental data for many applications, including the delivery and planning of services, election preparation, and response to disasters. In resource-poor settings, recent and reliable demographic data at subnational scales can often be lacking. National population and housing census data can be outdated, inaccurate, or missing key groups or areas, while registry data are generally lacking or incomplete. Moreover, at local scales accurate boundary data are often limited, and high rates of migration and urban growth make existing data quickly outdated. Here we review past and ongoing work aimed at producing spatially disaggregated local-scale population estimates, and discuss how new technologies are now enabling robust and cost-effective solutions. Recent advances in the availability of detailed satellite imagery, geopositioning tools for field surveys, statistical methods, and computational power are enabling the development and application of approaches that can estimate population distributions at fine spatial scales across entire countries in the absence of census data. We outline the potential of such approaches as well as their limitations, emphasizing the political and operational hurdles for acceptance and sustainable implementation of new approaches, and the continued importance of traditional sources of national statistical data.
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