1. |
- Peace, Alexander L., et al.
(författare)
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Evidence for Basement Reactivation during the Opening of the Labrador Sea from the Makkovik Province, Labrador, Canada : Insights from Field Data and Numerical Models
- 2018
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Ingår i: Geosciences. - : MDPI. - 2076-3263. ; 8:8
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Tidskriftsartikel (refereegranskat)abstract
- The onshore exposures adjacent to modern, offshore passive continental margins may preserve evidence of deformation from the pre-, syn-, and post-rift phases of continental breakup that allow us to investigate the processes associated with and controlling rifting and breakup. Here, we characterize onshore brittle deformation and pre-rift basement metamorphic mineral fabric from onshore Labrador in Eastern Canada in the Palaeoproterozoic Aillik Domain of the Makkovik Province. Stress inversion (1) was applied to these data and then compared to (2) numerical models of hybrid slip and dilation tendency, (3) independent calculations of the regional geopotential stress field, and (4) analyses of palaeo-stress in proximal regions from previous work. The stress inversion shows well-constrained extensional deformation perpendicular to the passive margin, likely related to pre-breakup rifting in the proto-Labrador Sea. Hybrid slip and dilatation analysis indicates that inherited basement structures were likely oriented in a favorable orientation to be reactivated during rifting. Reconstructed geopotential stresses illuminate changes of the ambient stress field over time and confirm the present paleo-stress estimates. The new results and numerical models provide a consistent picture of the late Mesozoic-Cenozoic lithospheric stress field evolution in the Labrador Sea region. The proto-Labrador Sea region was characterized by a persistent E-W (coast-perpendicular) extensional stress regime, which we interpret as the pre-breakup continental rifting that finally led to continental breakup. Later, the ridge push of the Labrador Sea spreading ridge maintained this general direction of extension. We see indications for anti-clockwise rotation of the direction of extension along some of the passive margins. However, extreme persistent N-S-oriented extension as indicated by studies further north in West Greenland cannot be confirmed.
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2. |
- Wilkinson, M., et al.
(författare)
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Partitioned postseismic deformation associated with the 2009 Mw 6.3 L'Aquila earthquake surface rupture measured using a terrestrial laser scanner
- 2010
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Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 37, s. L10309-
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Tidskriftsartikel (refereegranskat)abstract
- Using 3D terrestrial laser scan (TLS) technology, we have recorded postseismic deformation on and adjacent to the surface rupture formed during the 6th April 2009 L'Aquila normal faulting earthquake (Mw 6.3). Using surface modeling techniques and repeated surveys 8-124 days after the earthquake, we have produced a 4D dataset of postseismic deformation across a 3 x 65 m area at high horizontal spatial resolution. We detected millimetre-scale movements partitioned between discrete surface rupture slip and development of a hangingwall syncline over 10's of meters. We interpret the results as the signal of shallow afterslip in the fault zone. We find 52% of the total postseismic hangingwall vertical motion occurs as deformation within 30 m of the surface rupture. The total postseismic vertical motions are approximately 50% that of the coseismic. We highlight the importance of quantifying partitioned postseismic contributions when applying empirical slip-magnitude datasets to infer palaeoearthquake magnitudes. Citation: Wilkinson, M., et al. (2010), Partitioned postseismic deformation associated with the 2009 Mw 6.3 L'Aquila earthquake surface rupture measured using a terrestrial laser scanner.
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3. |
- Currow, David, et al.
(författare)
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A pragmatic, phase III, multisite, double-blind, placebo-controlled, parallel-Arm, dose increment randomised trial of regular, low-dose extended-release morphine for chronic breathlessness : Breathlessness, Exertion and Morphine Sulfate (BEAMS) study protocol
- 2017
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Ingår i: BMJ Open. - : BMJ. - 2044-6055. ; 7:7
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Tidskriftsartikel (refereegranskat)abstract
- Introduction Chronic breathlessness is highly prevalent and distressing to patients and families. No medication is registered for its symptomatic reduction. The strongest evidence is for regular, low-dose, extended-release (ER) oral morphine. A recent large phase III study suggests the subgroup most likely to benefit have chronic obstructive pulmonary disease (COPD) and modified Medical Research Council breathlessness scores of 3 or 4. This protocol is for an adequately powered, parallel-Arm, placebo-controlled, multisite, factorial, block-randomised study evaluating regular ER morphine for chronic breathlessness in people with COPD. Methods and analysis The primary question is what effect regular ER morphine has on worst breathlessness, measured daily on a 0-10 numerical rating scale. Uniquely, the coprimary outcome will use a FitBit to measure habitual physical activity. Secondary questions include safety and, whether upward titration after initial benefit delivers greater net symptom reduction. Substudies include longitudinal driving simulation, sleep, caregiver, health economic and pharmacogenetic studies. Seventeen centres will recruit 171 participants from respiratory and palliative care. The study has five phases including three randomisation phases to increasing doses of ER morphine. All participants will receive placebo or active laxatives as appropriate. Appropriate statistical analysis of primary and secondary outcomes will be used. Ethics and dissemination Ethics approval has been obtained. Results of the study will be submitted for publication in peer-reviewed journals, findings presented at relevant conferences and potentially used to inform registration of ER morphine for chronic breathlessness. Trial registration number NCT02720822; Pre-results.
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4. |
- Currow, D. C., et al.
(författare)
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Chronic breathlessness associated with poorer physical and mental health-related quality of life (SF-12) across all adult age groups
- 2017
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Ingår i: Thorax. - : BMJ. - 0040-6376 .- 1468-3296. ; 72:12, s. 1151-1153
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Tidskriftsartikel (refereegranskat)abstract
- Little is known about the impact of chronic breathlessness (modified Medical Research Council (mMRC) score ≥2 for most days, at least three of the last six months) on health-related quality of life (Short Form-12 (SF-12)). 3005 adults from randomly selected households were interviewed face-to-face in South Australia. mMRC ≥2 community prevalence was 2.9%. Adjusted analyses showed clinically meaningful and statistically significant decrements of physical and mental components of SF-12 (mean SF-12 summary scores in physical (-13.0 (-16.0 to -10.2)) and mental (-10.7 (-13.7 to -7.8)) components compared with people with mMRC=0) as chronic breathlessness severity increased, across five age groupings.
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5. |
- Foulger, Gillian R., et al.
(författare)
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The Iceland Microcontinent and a continental Greenland-Iceland-Faroe Ridge
- 2020
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Ingår i: Earth-Science Reviews. - : Elsevier BV. - 0012-8252 .- 1872-6828. ; 206
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Forskningsöversikt (refereegranskat)abstract
- The breakup of Laurasia to form the Northeast Atlantic Realm disintegrated an inhomogeneous collage of cratons sutured by cross-cutting orogens. Volcanic rifted margins formed that are underlain by magma-inflated, extended continental crust. North of the Greenland-Iceland-Faroe Ridge a new rift–the Aegir Ridge–propagated south along the Caledonian suture. South of the Greenland-Iceland-Faroe Ridge the proto-Reykjanes Ridge propagated north through the North Atlantic Craton along an axis displaced ~150 km to the west of the rift to the north. Both propagators stalled where the confluence of the Nagssugtoqidian and Caledonian orogens formed an ~300-km-wide transverse barrier. Thereafter, the ~150 × 300-km block of continental crust between the rift tips–the Iceland Microcontinent–extended in a distributed, unstable manner along multiple axes of extension. These axes repeatedly migrated or jumped laterally with shearing occurring between them in diffuse transfer zones. This style of deformation continues to the present day in Iceland. It is the surface expression of underlying magma-assisted stretching of ductile continental crust that has flowed from the Iceland Microplate and flanking continental areas to form the lower crust of the Greenland-Iceland-Faroe Ridge. Icelandic-type crust which underlies the Greenland-Iceland-Faroe Ridge is thus not anomalously thick oceanic crust as is often assumed. Upper Icelandic-type crust comprises magma flows and dykes. Lower Icelandic-type crust comprises magma-inflated continental mid- and lower crust. Contemporary magma production in Iceland, equivalent to oceanic layers 2–3, corresponds to Icelandic-type upper crust plus intrusions in the lower crust, and has a total thickness of only 10–15 km. This is much less than the total maximum thickness of 42 km for Icelandic-type crust measured seismically in Iceland. The feasibility of the structure we propose is confirmed by numerical modeling that shows extension of the continental crust can continue for many tens of millions of years by lower-crustal ductile flow. A composition of Icelandic-type lower crust that is largely continental can account for multiple seismic observations along with gravity, bathymetric, topographic, petrological and geochemical data that are inconsistent with a gabbroic composition for Icelandic-type lower crust. It also offers a solution to difficulties in numerical models for melt-production by downward-revising the amount of melt needed. Unstable tectonics on the Greenland-Iceland-Faroe Ridge can account for long-term tectonic disequilibrium on the adjacent rifted margins, the southerly migrating rift propagators that build diachronous chevron ridges of thick crust about the Reykjanes Ridge, and the tectonic decoupling of the oceans to the north and south. A model of complex, discontinuous continental breakup influenced by crustal inhomogeneity that distributes continental material in growing oceans fits other regions including the Davis Strait, the South Atlantic and the West Indian Ocean.
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7. |
- Kellokumpu-Lehtinen, PLI, et al.
(författare)
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Triweekly docetaxel versus biweekly docetaxel as a treatment for advanced castration resistant prostate cancer: Quality of life analysis
- 2014
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Ingår i: JOURNAL OF CLINICAL ONCOLOGY. - : American Society of Clinical Oncology (ASCO). - 0732-183X .- 1527-7755. ; 32:4
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- 23 Background: Bi-weekly docetaxel (T) with prednisone improved progression free survival and overall survival when compared with the standard tri-weekly T as first-line treatment for advanced castration resistant prostate cancer (CRPC) (Lancet Oncol. 2013;14:117-124). We report here the quality of life (QoL) results of this prospective randomized trial. Methods: Three hundred and forty-six patients were randomly allocated centrally to receive intravenous therapy T of either 75 mg/m² d1 q3 wks (the triweekly arm) or 50 mg/m² d1 and d 14, q4 wks (the biweekly arm) (identifier NCT00255606). Prednisone (10 mg/d) was administered orally in both groups. The baseline patients characteristics were well balanced between the groups with respect to the performance status, mean age (69, range 45 to 87 vs. 68, range 46 to 85), and median serum prostate-specific antigen (PSA) content (109 µg/L, range 11 to 1,230 vs. 116 µg/L, range 12 to 1,870). Quality of life (QoL), the frequency and severity of symptoms including pain were assessed using the Functional Assessment of Cancer Therapy-Prostate (FACT-P) version 4.0 questionnaire. Results: The baseline (QoL) of both treatment groups was compared to QoL after six months of the treatment within each treatment group and between groups. Changes in fatigue, symptoms of pain and nausea, and the overall performance status did not differ between the groups. There were statistically significant differences in overall quality of life values (p=0.010) and discomforting pain values (p=0.028) favoring the bi-weekly treatment arm. Conclusions: Bi-weekly T is better tolerated than the tri-weekly standard T. Following the results from the clinical outcome and the QoL outcome in the PROSTY trial we would recommend the use of bi-weekly docetaxel as first line treatment of CRPC Clinical trial information: NCT00255606.
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8. |
- McCaffrey, J.P., et al.
(författare)
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Surface damage formation during ion-beam thinning of samples for transmission electron microscopy
- 2001
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Ingår i: Ultramicroscopy. - 0304-3991 .- 1879-2723. ; 87:3, s. 97-104
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Tidskriftsartikel (refereegranskat)abstract
- All techniques employed in the preparation of samples for transmission electron microscopy (TEM) introduce or include artifacts that can degrade the images of the materials being studied. One significant cause of this image degradation is surface amorphization. The damaged top and bottom surface layers of TEM samples can obscure subtle detail, particularly at high magnification. Of the techniques typically used for TEM sample preparation of semiconducting materials, cleaving produces samples with the least surface amorphization, followed by low-angle ion milling, conventional ion milling, and focused ion beam (FIB) preparation. In this work, we present direct measurements of surface damage on silicon produced during TEM sample preparation utilizing these techniques. The thinnest damaged layer formed on a silicon surface was measured as 1.5nm thick, while an optimized FIB sample preparation process results in the formation of a 22nm thick damaged layer. Lattice images are obtainable from all samples. Copyright © 2001 Elsevier Science B.V.
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9. |
- Otto, Ilona M., et al.
(författare)
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Social tipping dynamics for stabilizing Earth's climate by 2050
- 2020
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : The National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 117:5, s. 2354-2365
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Tidskriftsartikel (refereegranskat)abstract
- Safely achieving the goals of the Paris Climate Agreement requires a worldwide transformation to carbon-neutral societies within the next 30 y. Accelerated technological progress and policy implementations are required to deliver emissions reductions at rates sufficiently fast to avoid crossing dangerous tipping points in the Earth's climate system. Here, we discuss and evaluate the potential of social tipping interventions (STIs) that can activate contagious processes of rapidly spreading technologies, behaviors, social norms, and structural reorganization within their functional domains that we refer to as social tipping elements (STE5). STE5 are subdomains of the planetary socioeconomic system where the required disruptive change may take place and lead to a sufficiently fast reduction in anthropogenic greenhouse gas emissions. The results are based on online expert elicitation, a subsequent expert workshop, and a literature review. The STIs that could trigger the tipping of STE subsystems include 1) removing fossil-fuel subsidies and incentivizing decentralized energy generation (STE1, energy production and storage systems), 2) building carbon-neutral cities (STE2, human settlements), 3) divesting from assets linked to fossil fuels (STE3, financial markets), 4) revealing the moral implications of fossil fuels (STE4, norms and value systems), 5) strengthening climate education and engagement (STE5, education system), and 6) disclosing information on greenhouse gas emissions (STE6, information feedbacks). Our research reveals important areas of focus for larger-scale empirical and modeling efforts to better understand the potentials of harnessing social tipping dynamics for climate change mitigation.
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10. |
- Schiffer, Christian, et al.
(författare)
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Structural inheritance in the North Atlantic
- 2020
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Ingår i: Earth-Science Reviews. - : Elsevier BV. - 0012-8252 .- 1872-6828. ; 206
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Forskningsöversikt (refereegranskat)abstract
- The North Atlantic, extending from the Charlie Gibbs Fracture Zone to the north Norway-Greenland-Svalbard margins, is regarded as both a classic case of structural inheritance and an exemplar for the Wilson-cycle concept. This paper examines different aspects of structural inheritance in the Circum-North Atlantic region: 1) as a function of rejuvenation from lithospheric to crustal scales, and 2) in terms of sequential rifting and opening of the ocean and its margins, including a series of failed rift systems. We summarise and evaluate the role of fundamental lithospheric structures such as mantle fabric and composition, lower crustal inhomogeneities, orogenic belts, and major strike-slip faults during breakup. We relate these to the development and shaping of the NE Atlantic rifted margins, localisation of magmatism, and microcontinent release. We show that, although inheritance is common on multiple scales, the Wilson Cycle is at best an imperfect model for the Circum-North Atlantic region. Observations from the NE Atlantic suggest depth dependency in inheritance (surface, crust, mantle) with selective rejuvenation depending on time-scales, stress field orientations and thermal regime. Specifically, post-Caledonian reactivation to form the North Atlantic rift systems essentially followed pre-existing orogenic crustal structures, while eventual breakup reflected a change in stress field and exploitation of a deeper-seated, lithospheric-scale shear fabrics. We infer that, although collapse of an orogenic belt and eventual transition to a new ocean does occur, it is by no means inevitable.
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