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3. |
- Calner, Mikael, et al.
(author)
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Från kusten till djuphavet
- 2006
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In: Geobiosfären - en introduktion. - 9789144036700 ; , s. 315-322
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Book chapter (other academic/artistic)
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6. |
- Andreasson, Per Gunnar, et al.
(author)
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Magmatism during late Ordovician-early Silurian accretion of the Caledonides of Arctic Scandinavia : the Halti-Guolasjavri area revisited
- 2023
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In: Norwegian Journal of Geology. - : Geological Society of Norway. - 2387-5852 .- 2387-5844. ; 103:2
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Journal article (peer-reviewed)abstract
- In the Scandinavian Caledonides, evidence of syn-collisional magmatism related to extensional basin development immediately prior to late Silurian Baltica-Laurentia collision was considered restricted to exotic terranes until late Silurian ages were obtained from the Halti Igneous Complex (HIC), hosted by a thrust sheet (Corrovarre Nappe, CN) of continental affinity. Various orogenic models for the extension and magmatism, a. o. subduction flip, slab roll-back, and ridge subduction have been proposed. Crucial factors include the affinity (Baltican or exotic) of the CN, and the nature of the debated unconformity at the base of the overlying exotic Vaddas Nappe (Koli). This study reexamines a critical tectonostratigraphic section and reports U-Pb zircon ages (441-436 Ma) of palingenetic granitic dykes generated by the HIC. We reinterpret the CN as a slice of the continental margin and accreted with some other nappes of the Seve Nappe Complex (SNC) which decoupled from the continent-ocean transition (COT) at an early stage of subduction of the margin. The lower part of the bipartite Vaddas Nappe, composed of a very dense dolerite dyke swarm with screens of quartzite, marble and subordinate black schist, is reinterpreted as a continuation northwards of the uppermost nappe of the SNC in Indre Troms, derived from the Ediacaran outermost continental margin. The contact with the overlying telescoped succession of conglomerates, marbles, volcanics and turbidites of the Vaddas Nappe is tentatively interpreted as a tectonised unconformity. To a classical model of back-arc spreading outboard of Laurentia during closure of the Iapetus Ocean, we add the arrival of Baltica, with a prism of decoupled slices of the COT and exhumed/exhuming UHP nappes. The spreading centre of the basin provides a plausible setting for gabbros and pillow lavas of the Vaddas Nappe, and the shores of the basin for a Seve-Koli unconformity. Future PTt studies are required in order to be able to relate the proposed shallow, syn-exhumation HIC magmatism to the tectonometamorphic evolution of the HP-UHP nappes of the SNC.
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7. |
- Andréasson, Per Gunnar, et al.
(author)
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Seve terranes of the Kebnekaise Mts., Swedish Caledonides, and their amalgamation, accretion and affinity
- 2018
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In: GFF. - : Informa UK Limited. - 1103-5897 .- 2000-0863. ; 140:3, s. 264-291
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Journal article (peer-reviewed)abstract
- A major allochthon of the Scandinavian Caledonides, the Seve belt has traditionally been considered to be derived from the rifted margin and continent-ocean transition (COT) of Baltica. However, geochronological results obtained from its inferred northern equivalent, the Kalak Nappe Complex (KNC), have been taken to indicate an exotic affinity of this complex and of also Seve terranes, an interpretation adopted in recent palaeogeographic models. In the Kebnekaise Mts., the COT is represented by the Kebnekaise terrane composed of amphibolitized dykes of gabbro and dolerite of depleted magma source and rare felsic and ultramafic rocks. Coronitic dolerite and gabbro with abundant rutile suggest high pressures before or during amalgamation with the underlying Mårma terrane, composed of quartzofeldspathic gneisses intruded by mafic and granitic rocks, the latter including a previously dated c. 845 Ma-old granite. The granite mingled with mildly alkaline dolerites chemically similar to transitional basalts of continental rifts. Following emplacement at shallow (andalusite stability) crustal levels, the igneous complex and host rocks underwent extensive deformation, metamorphism within the sillimanite-kyanite stability field and local migmatization. The Kebnekaise and Mårma terranes amalgamated in early Ordovician as indicated by the U-Pb age of 487±7 Ma obtained from titanite fabrics of deformed granite in thrust vicinity, and by 40Ar-39Ar results. The pressure increase in both terranes suggests that amalgamation occurred during initial subduction and imbrication. Correlation of the Mårma terrane with the KNC is discussed. Results obtained in this study give no reason to ascribe an exotic affinity to the Seve terranes of the Kebnekaise Mts.
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8. |
- Andréasson, Per-Gunnar, et al.
(author)
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Subduction-flip during Iapetus Ocean closure and Baltica-Laurentia collision, Scandinavian Caledonides
- 2003
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In: Terra Nova: the European journal of geosciences. - : Wiley. - 0954-4879. ; 15:6, s. 362-369
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Journal article (peer-reviewed)abstract
- Evidence is presented here from the northern Scandinavian Caledonides for development of an extensional basin of Ashgill to Mid Llandovery age along the Baltoscandian margin immediately prior to Baltica-Laurentia collision. U/Pb multigrain and ion microprobe zircon dating of plagiogranites in the Halti Igneous Complex complement previous baddeleyite and zircon dating of a dolerite dyke, and zircon dating of anatectic granite; they demonstrate that this dunite, troctolite, gabbro, sheeted-dyke complex ranges in age from c. 445 to 435 Ma. The dolerite dykes intruded and melted arkoses of inferred Neoproterozoic age. This evidence, taken together with previous documentation of ophiolites (Solund-Stavfjord), ophiolite-like associations (Sulitjelma Igneous Complex) and several other mafic suites (e.g. Rana, Artfjallet) of Ashgill to Llandovery age further south in the northern Scandinavian Caledonides, implies that Scandian collisional orogeny along this nearly 2000-km-long mountain belt was immediately preceeded by development of short-lived marginal basins. The latter developed during the final closure of the Iapetus Ocean and are inferred to be of back-arc origin, some (perhaps all) related to E-dipping subduction. Collision of the continents at c. 435 Ma is inferred to have induced a flip in subduction polarity, leading to underthrusting of Laurentia by Baltica.
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9. |
- Andréasson, Per Gunnar
(author)
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The continent-ocean (Seve-Köli) boundary in the Sarek-Padjelanta Mts. revisited : Swedish Caledonides
- 2020
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In: GFF. - : Informa UK Limited. - 1103-5897 .- 2000-0863. ; 142:2, s. 125-138
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Journal article (peer-reviewed)abstract
- In the Swedish Caledonides, the continent-ocean boundary is represented by the basal thrust of the Iapetus-derived Köli Nappe Complex (KNC) which overlies the Seve Nappe Complex (SNC) derived from the outer rifted margin of Baltica and the continent-ocean transition (COT). Current maps and literature subdivide the Seve teconostratigraphy in northern Sweden (Sarek-Padjelanta region) into three mega-lenses, the lowest of which (Vaimok lens) is composed of quartz-feldspathic gneisses and subordinate marble, all hosting eclogites. It is overlain by the Sarek lens composed of a COT dyke complex and, along its western margin, a narrow belt of phyllites, schists, quartzite, marbles and greenschists. Overlying this belt is Tsäkkok lens of the same composition as the Vaimok lens. The situation with an intermediate-pressure and often excellently preserved sheeted-dyke complex intercalated between two lenses of complexly deformed high-pressure rocks invited to intricate models of accretion, including out-of-sequence stacking of slices of the continental margin during early Ordovician subduction. Based on a detailed study of a select area and examination of the evolution of previous concepts, this study reinterprets the narrow belt along the western margin of the Sarek Lens as typical of the lower KNC. The favoured explanation of the presence of intermediate-pressure Köli rocks below high-pressure Seve rocks is recumbent folding and/or mega-sheath folding of the Seve-Köli nappe sequence during Scandian (Siluro-Devonian) accretion, by analogy with the situation in places in the central Swedish Caledonides. Previous models of early out-of-sequence stacking during subduction of the continental margin need reconsideration.
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12. |
- Bergerat, Francoise, et al.
(author)
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Evolution of paleostress fields and brittle deformation of the Tornquist Zone in Scania (Sweden) during Permo-Mesozoic and Cenozoic times
- 2007
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In: Tectonophysics. - : Elsevier BV. - 0040-1951. ; 444, s. 93-110
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Journal article (peer-reviewed)abstract
- The NW-SE oriented Sorgenfrei–Tornquist Zone (STZ) has been thoroughly studied during the last 25 years, especially by means of well data and seismic profiles. We present the results of a first brittle tectonic analysis based on about 850 dykes, veins and minor fault-slip data measured in the field in Scania, including paleostress reconstruction. We discuss the relationships between normal and strike-slip faulting in Scania since the Permian extension to the Late Cretaceous–Tertiary structural inversions. Our paleostress determinations reveal six successive or coeval main stress states in the evolution of Scania since the Permian. Two stress states correspond to normal faulting with NE-SW and NW-SE extensions, one stress state is mainly of reverse type with NESW compression, and three stress states are strike-slip in type with NNW-SSE, WNW-ESE and NNE-SSW directions ofcompression. The NE-SW extension partly corresponds to the Late Carboniferous–Permian important extensional period, dated by dykes and fault mineralisations. However extension existed along a similar direction during the Mesozoic. It has been locally observed until within the Danian. A perpendicular NW-SE extension reveals the occurrence of stress permutations. The NNW-SSE strike-slip episode is also expected to belong to the Late Carboniferous–Permian episode and is interpreted in terms of right-lateral wrench faulting along STZ-oriented faults. The inversion process has been characterised by reverse and strike-slip faulting related to the NE-SW compressional stress state. This study highlights the importance of extensional tectonics in northwest Europe since the end of the Palaeozoic until the end of the Cretaceous. The importance and role of wrench faulting in the tectonic evolution of the Sorgenfrei–Tornquist Zone are discussed.
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15. |
- Calner, Mikael, et al.
(author)
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Geologiska råvaror; metanhydrater
- 2006
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In: Geobiosfären - en introduktion. - 9789144036700 ; , s. 497-498
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Book chapter (other academic/artistic)
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16. |
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17. |
- Gee, David G., et al.
(author)
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Baltoscandian margin, Sveconorwegian crust lost by subduction during Caledonian collisional orogeny
- 2017
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In: GFF. - : Informa UK Limited. - 1103-5897 .- 2000-0863. ; 139:1, s. 36-51
-
Journal article (peer-reviewed)abstract
- Underthrusting of Laurentia by the continental margin of Baltica during Caledonian orogeny resulted in the lateral emplacement of Iapetus Ocean-related terranes of the Upper Allochthon at least 500 km onto Baltica. The underlying Lower and Middle allochthons of the Baltoscandian margin mostly comprise Cryogenian, Ediacaran and Cambro-Silurian sedimentary successions; basement to these formations are present only as minor, isolated fragments, except at the base of the Middle Allochthon and within the underlying windows. The upper parts of the Middle Allochthon are notable for the presence of early Ediacaran dyke-swarms and other components of the Baltoscandian continent-ocean transition zone (COT). New data are presented here on the c. 610 Ma age of the COT-related dolerites in the Kalak Nappe Complex in Northern Norway and also on detrital zircons in the underlying Laksefjord and Gaissa nappes. The former confirms that the Baltoscandian COT has a similar age along the length of the orogen; the latter shows that the detrital zircon signatures in the Lower and Middle allochthons are comparable throughout the orogen. These sedimentary rocks have dominating populations of Mesoproterozoic to latest Palaeoproterozoic zircons similar to those from southern parts of the orogen, where Sveconorwegian complexes comprise the basement to the Caledonides. Thus, they help define the probable character and age of the crystalline basement that existed along this outer margin of Baltica during the Neoproterozoic, continental lower crust that was partly subducted during Ordovician continent-arc collision and subsequently lost beneath Laurentia during the 50 million years of Scandian collisional orogeny.
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19. |
- Gee, David Godfrey, et al.
(author)
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Detrital zircon signatures of the Baltoscandian margin along the Arctic Circle Caledonides in Sweden: The Sveconorwegian connection
- 2015
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In: Precambrian Research. - : Elsevier. - 0301-9268 .- 1872-7433. ; 265, s. 40-56
-
Journal article (peer-reviewed)abstract
- New evidence is presented here that the Sveconorwegian Orogen continued northwards from type areas in southwestern Scandinavia along the Baltoscandian outer margin into the high Arctic. The Silver Road (Silvervägen) profile through the Scandinavian Caledonides, located in Sweden along the Arctic Circle at 66–67◦ N, provides a full section through the tectonostratigraphy of the Baltoscandian margin from the Autochthon, via the Lower Allochthon to the upperment parts of the Middle Allochthon. Metamorphic grade increases upwards through the nappes, being low greenschist facies at lowest levels and increas- ing to eclogite grade in the highest parts of the Seve Nappe Complex, the latter being related to early Ordovician subduction of the Baltoscandian outermost margin. The sedimentary rocks range in age from Neoproterozoic to Ordovician and provide evidence of the changes of environment from the Baltoscan- dian platform, westwards out over the Cryogenian rifted margin to the continent-ocean transition zone; also the Ordovician foreland basin. Twelve samples of psammites from the different tectonostratigraphic levels have yielded U/Pb detrital zircon age-signatures that reflect the changing character of their pro- venance. Autochthonous sandstones are derived from late Paleoproterozoic (1800–1950 Ma) crystalline rocks in the vicinity to the east of the thrust front. Ediacaran-early Cambrian quartzites of the Lower Allochthon also yield mainly late Paleoproterozoic zircon signatures, but with subordinate Mesopro- terozoic and late Archaean populations, whilst mid Ordovician, W-derived foreland basin turbidites are dominated by Sveconorwegian (950–1100 Ma) signatures, with subordinate older Mesoproterozoic to latest Paleoproterozoic populations. All samples from the lower parts of the Middle Allochthon (lacking dolerite dykes) have signatures that are dominated by latest Paleoproterozoic and early Mesoproterozoic ages, with subordinate populations down to Sveconorwegian ages; the latter dominate the overlying Särv nappes and also the Seve Nappe Complex, where c. 945 Ma rhyodacites have been previously reported. This evidence of Sveconorwegian source rocks in the hinterland, taken together with previously pub- lished detrital zircon data farther south and north of the Arctic Circle, clearly favours the interpretation that the Sveconorwegian Orogen, during the Neoproterozoic, extended along the entire Baltoscandian outer margin into the high Arctic.
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20. |
- Gee, David G., et al.
(author)
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Middle thrust sheets in the Caledonide orogen, Sweden: the outer margin of Baltica, the continent–ocean transition zone and late Cambrian–Ordovician subduction–accretion
- 2020
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In: Sweden. - : Geological Society of London. - 9781786204608 ; 50:1, s. 517-548
-
Book chapter (other academic/artistic)abstract
- Nappes of continental outer and outermost margin affinities (Middle Allochthon) were transported from locations west of the present Norwegian coast and thrust eastwards onto the Baltoscandian foreland basin and platform. They are of higher metamorphic grade than underlying thrust sheets and most are more penetratively deformed. These allochthons are treated here in three groups. The lower thrust sheets comprise Paleoproterozoic crystalline basement (e.g. Tännäs Augen Gneiss Nappe) and greenschist facies, Neoproterozoic, siliciclastic metasedimentary rocks (e.g. Offerdal Nappe). These are overthrust by a Cryogenian−Ediacaran succession intruded by c. 600 Ma dolerites (Baltoscandian Dyke Swarm) with an affinity to mid-ocean ridge basalt containing normal to enriched incompatible element contents (Särv Nappes). The upper sheets are dominated by higher-grade allochthons (Seve Nappe Complex) with similar, mainly siliciclastic sedimentary protoliths, more mafic magmatism and some solitary ultramafic bodies. Within this early Ediacaran continent−ocean transition zone (COT) assemblage, generally metamorphosed in amphibolite facies, some nappes experienced migmatization, and eclogites are present. Evidence of ultrahigh-pressure metamorphism has been obtained from garnet peridotites and eclogites; recently, microdiamonds have been discovered in paragneisses. Subduction of the COT started by the late Cambrian and accretion continued through the Ordovician, prior to the Baltica–Laurentia collision. Thrusting of all these Middle allochthons onto the foreland basin exceeds a distance of 400 km.
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24. |
- Hang, Trieu, et al.
(author)
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Natural surface floaters in image-based river surface velocimetry: Insights from a case study
- 2024
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In: Flow Measurement and Instrumentation. - : Elsevier. - 0955-5986 .- 1873-6998. ; 96
-
Journal article (peer-reviewed)abstract
- This study focuses on utilizing image techniques for river velocity measurement, with a specific emphasis onnatural surface floating patterns. Employing a multi-camera system, we conducted 3D measurements on riversurfaces, including surface velocity and water surface reconstruction. A pattern-based tracking approach hasbeen adopted to improve the performance of image measurements on different types of natural floating tracers.The study employs the following approaches: 3D Lagrangian Pattern Tracking Velocimetry (3D-LPTV), 2DLagrangian Pattern Velocimetry (2D- LPTV), and Large-scale Particle Image Velocimetry (LSPIV), for surfacevelocity estimation. The outcomes revealed that all three approaches yielded consistent results in terms ofaveraged velocity. However, the LSPIV method produced about two times higher uncertainty in measured velocitiescompared to the other methods. A strategy to assess the quality of river surface patterns in velocityestimation is presented. Specifically, the sum of squared interrogation area intensity gradient (SSIAIG) was foundto be strongly correlated with measurement uncertainty. Additionally, a term related to the peak sidelobe ratio(PSR) of the cross-correlation map was found as an effective constraint, ensuring the image-tracking processachieves high reliability. The precision of measurements increases corresponding to the increase of image intensitygradient and PSR.
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25. |
- Hang, Trieu, et al.
(author)
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Photogrammetry for Free Surface Flow Velocity Measurement : From Laboratory to Field Measurements
- 2021
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In: Water. - : MDPI. - 2073-4441. ; 13:12
-
Journal article (peer-reviewed)abstract
- This study describes a multi-camera photogrammetric approach to measure the 3D velocityof free surface flow. The properties of the camera system and particle tracking velocimetry (PTV)algorithm were first investigated in a measurement of a laboratory open channel flow to prepare forfield measurements. The in situ camera calibration methods corresponding to the two measurementsituations were applied to mitigate the instability of the camera mechanism and camera geometry.There are two photogrammetry-based PTV algorithms presented in this study regarding differenttypes of surface particles employed on the water flow. While the first algorithm uses the particletracking method applied for individual particles, the second algorithm is based on correlation-basedparticle clustering tracking applied for clusters of small size particles. In the laboratory, referencedata are provided by particle image velocimetry (PIV) and laser Doppler velocimetry (LDV). Thedifferences in velocities measured by photogrammetry and PIV, photogrammetry and LDV are 0.1%and 3.6%, respectively. At a natural river, the change of discharges between two measurement timesis found to be 15%, and the corresponding value reported regarding mass flow through a nearbyhydropower plant is 20%. The outcomes reveal that the method can provide a reliable estimation of3D surface velocity with sufficient accuracy.
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26. |
- Johansson, Gunnar, et al.
(author)
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Cost effectiveness of budesonide/formoterol for maintenance and reliever therapy versus salmeterol/fluticasone plus salbutamol in the treatment of asthma
- 2006
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In: PharmacoEconomics (Auckland). - : Springer Science and Business Media LLC. - 1170-7690 .- 1179-2027. ; 24:7, s. 695-708
-
Journal article (peer-reviewed)abstract
- INTRODUCTION: Budesonide/formoterol (Symbicort) Maintenance And Reliever Therapy (SMART) is an effective and well tolerated treatment option for patients with asthma. We compared the cost effectiveness from a societal perspective of this one-inhaler regimen with that of maintenance salmeterol/fluticasone propionate (Seretide) plus salbutamol (albuterol) as needed (Seretide) Fixed Combination [SFC]). STUDY DESIGN: A cost-effectiveness analysis was performed based on effectiveness and resource-utilisation data collected prospectively in a randomised, 12-month study performed in 2143 patients in 16 countries. Resource utilisation data were pooled and unit costs (euro, year 2003 values) from Italy, France, the UK and Germany were used to generate estimates of direct and total costs per patient per year and cost per severe exacerbation avoided. METHODS: Adolescents and adults with asthma (n = 2143; mean forced expiratory volume in 1 second [FEV(1)] 73% predicted; mean inhaled corticosteroid [ICS] dose 884 microg/day) were randomised to SMART or SFC. The effectiveness measure used was the number of severe exacerbations per patient per year. Direct costs included medication use (budesonide/formoterol 160microg/4.5microg or salmeterol/fluticasone 50microg/100microg, 50microg/250microg or 50microg/500microg plus salbutamol) and nonmedication-related resource use, including days in hospital, emergency room visits, specialist or primary care physician visits and other healthcare provider contacts. Indirect costs, including the number of days when the patient or their carer was unable to attend to their normal daily activities, were also assessed. The study assumed a European societal perspective (i.e. including direct and indirect costs). RESULTS: Treatment with SMART resulted in significantly fewer severe exacerbations per patient per year compared with SFC (0.24 vs 0.31 events per patient per year; p = 0.0025). Resource use was low in both groups. Medication costs accounted for the majority of the total costs. The increased effectiveness of SMART was achieved at a reduced or similar cost compared with SFC. SMART dominated when German unit costs were applied (i.e. there was a statistically significant reduction in both costs and number of exacerbations). In all other countries, the incremental cost-effectiveness ratios showed that there was a reduction in mean total cost per exacerbation avoided; however, this difference was not statistically significant. CONCLUSION: This analysis demonstrates that, compared with SFC, SMART may be cost effective from a societal perspective for the treatment of patients with asthma in Italy, Germany, France and the UK. SMART provided a reduction in the number of severe exacerbations per patient per year, at no statistically significant increase in cost - or even at a lower cost - compared with SFC plus as-needed reliever salbutamol.
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27. |
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28. |
- Minta, Karolina, et al.
(author)
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Brevican and Neurocan Peptides as Potential Cerebrospinal Fluid Biomarkers for Differentiation Between Vascular Dementia and Alzheimer's Disease
- 2021
-
In: Journal of Alzheimer's disease : JAD. - 1387-2877 .- 1875-8908. ; 79:2, s. 729-741
-
Journal article (peer-reviewed)abstract
- BACKGROUND: Brevican and neurocan are central nervous system-specific extracellular matrix proteoglycans. They are degraded by extracellular enzymes, such as metalloproteinases. However, their degradation profile is largely unexplored in cerebrospinal fluid (CSF).OBJECTIVE: The study aim was to quantify proteolytic peptides derived from brevican and neurocan in human CSF of patients with Alzheimer's disease (AD) and vascular dementia (VaD) compared with controls.METHODS: The first cohort consisted of 75 individuals including 25 patients with AD, 7 with mild cognitive impairment (MCI) diagnosed with AD upon follow-up, 10 patients with VaD or MCI diagnosed with VaD upon follow-up, and 33 healthy controls and cognitively stable MCI patients. In the second cohort, 31 individuals were included (5 AD patients, 14 VaD patients and 12 healthy controls). Twenty proteolytic peptides derived from brevican (n = 9) and neurocan (n = 11) were quantified using high-resolution parallel reaction monitoring mass spectrometry.RESULTS: In the first cohort, the majority of CSF concentrations of brevican and neurocan peptides were significantly decreased inVaDas compared withADpatients (AUC = 0.83.0.93, p≤0.05) and as compared with the control group (AUC = 0.79.0.87, p ≤ 0.05). In the second cohort, CSF concentrations of two brevican peptides (B87, B156) were significantly decreased in VaD compared with AD (AUC = 0.86.0.91, p ≤ 0.05) and to controls (AUC = 0.80.0.82, p ≤ 0.05), while other brevican and neurocan peptides showed a clear trend to be decreased in VaD compared with AD (AUC = 0.64.80, p > 0.05). No peptides differed between AD and controls.CONCLUSION: Brevican and neurocan peptides are potential diagnostic biomarkers for VaD, with ability to separate VaD from AD.
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29. |
- Offstad, Jon, et al.
(author)
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The Scandinavian multicenter hemodynamic evaluation of the SJM Regent aortic valve
- 2011
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In: Journal of Cardiothoracic Surgery. - : Springer Science and Business Media LLC. - 1749-8090. ; 6:163
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Journal article (peer-reviewed)abstract
- Background: 112 patients who received small and medium sized St.Jude Regent heart valves (19-25 mm) at 7 Scandinavian centers were studied between January 2003 and February 2005 to obtain non-invasive data regarding the hemodynamic performance at rest and during Dobutamine stress echocardiography (DSE) testing one year after surgery. Material and methods: 46 woman and 66 men, aged 61.8 +/- 9.7 (18-75) years, were operated on for aortic regurgitation (17), stenosis (65), or mixed dysfunction (30). Valve sizes were 19 mm (6), 21 mm (33), 23 mm (41), 25 mm (30). Two patients receiving size 27 valves were excluded from the hemodynamic evaluation. Pledgets were used in 100 patients, everted mattress in 66 and simple interrupted sutures in 21. Valve orientation varied and was dependent on the surgeons' choice. 34 patients (30.4%) underwent concomitant coronary artery surgery. Results: There were two early deaths (1.8%) and three late deaths, one because of pancreatic cancer. Late events during follow-up were: non structural dysfunction (1), bleeding (2), thromboembolism (2). At one year follow up 93% of the patients were in NYHA classes 1-2 versus 47.8% preoperatively. Dobutamine stress echocardiography (DSE) was performed in a total of 66 and maximal peak stress was reached in 61 patients. During DSE testing, the following statistically significant changes took place: Heart rate increased by 73.0%, cardiac output by 85.5%, left ventriclular ejection fraction by 19.6%, and maximal mean prosthetic transvalvular gradient by 133.8%, whereas the effective orifice area index did not change. Left ventricular mass fell during one year from 215 +/- 63 to 197 +/- 62 g (p < 0.05). Conclusion: The Dobutamine test induces a substantial stress, well suitable for echocardiographic assessment of prosthesis valve function and can be performed in the majority of the patients. The changes in pressure gradients add to the hemodynamic characteristics of the various valve sizes. In our patients the St. Jude Regent valve performed satisfactory at rest and under pharmacological stress situation.
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30. |
- Paulsson, Oskar, et al.
(author)
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Attempted break-up of Rodinia at 850 Ma: geochronological evidence from the Seve-Kalak Superterrane, Scandinavian Caledonides
- 2002
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In: Journal of the Geological Society. - 2041-479X. ; 159:6, s. 751-761
-
Journal article (peer-reviewed)abstract
- Lower thrust sheets of the Scandinavian Caledonides derive from the margin of Baltica, which was imbricated during Early Palaeozoic closure of oceans formed during separation of the Baltica, Laurentia and Siberia cratons. At Vistas (Kebnekaise Mts), the Seve Nappe Complex preserves rare lenses of a dolerite-intruded granite formed by anatexis during emplacement of gabbro into metasedimentary rocks. Ion microprobe U-Pb dating of prismatic zircons from the granite yielded an age of 845 +/- 14 Ma (mean square weighed deviation (MSWD) 1.15), interpreted to date magmatic crystallization. Cores of complex crystals indicate protolith ages of 1778 +/- 11 Ma (MSWD 0.86); one core yielded an Archaean age. From narrow rims, a 605 +/- 42 Ma metamorphic age is obtained, and is interpreted to reflect the emplacement of the extensive Vendian rift magmatic dolerite dyke swarm. The age pattern allows correlation with a previously dated magmatic complex within the equivalent Kalak Nappe Complex 300 km to the north. Bimodal magmatic complexes with this age pattern do not occur within the basement of the Caledonide foreland, nor elsewhere within the Baltic Shield. However, recent reinterpretations of the Knoydartian event in Scotland as rift related invites correlation with the West Highland Granite Gneiss, which intruded Moine metasedimentary rocks at c. 870 Ma. In Central Taimyr, 850-900 Ma granites of continental crustal derivation and with 1800-1900 Ma Sm-Nd model age occur associated with c. 740 Ma plagiogranites. Using recent palaeogeographical reconstructions, we interpret the evidence of 850-900 Ma magmatism, in Scandinavia, Scotland and Taimyr as bimodal rift magmatism in connected arms during an attempted break-up of Rodinia.
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31. |
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32. |
- Shumlyanskyy, Leonid, et al.
(author)
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The U–Pb zircon and baddeleyite ages of the Neoproterozoic Volyn Large Igneous Province: implication for the age of the magmatism and the nature of a crustal contaminant
- 2016
-
In: GFF. - 1103-5897 .- 2000-0863. ; 138, s. 17-30
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Journal article (peer-reviewed)abstract
- The Volyn continental flood basalt province is situated on the western margin of the East European platform and constitutes a significant portion of the passive continental margin sequence formed along the Trans-European Suture Zone in response to Rodinia break-up in the Neoproterozoic. In Ukraine, the volcanogenic sequence is subdivided into suites called Zabolottya, Babyne and Ratne,which together with the lowermost terrigeneous Gorbashy suite comprise the Volyn series. Magmatic zircons from one high-Ti basalt sample yielded an age of 573 ± 14 Ma, whereas grains isolated from a rhyolitic dacite yielded an age of 571 ± 13 Ma. Baddeleyite from the olivine dolerite sample gave an older 206Pb/238U age of 626 ± 17 Ma, whereas the 207Pb/206Pb weighted average age of 567 ± 61 Ma is close to the zircon ages. Zircons separated from the other basaltic samples are much older and crystallized at c. 1290, 1470, 1820-1860, 1930-2050 and 2660 Ma. Ages in the 1820-1860 and 1930-2050 Ma time spans correspond to the ages of the Precambrian basement that underlies the Volyn province. However, the sources for the 1290, 1470 and 2660 Ma zircons are unknown, and these zircons must have been derivedfrom more distal areas.
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33. |
- Singh, S., et al.
(author)
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2.0 Ga Granite of the Lower Package of the Higher Himalayan Crystallines, Maglad Khad, Sutlej Valley, Himachal Pradesh
- 2006
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In: Journal of the Geological Society of India. - 0016-7622 .- 0974-6889. ; 67:3, s. 295-300
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Journal article (peer-reviewed)abstract
- Along the Sutlej valley, the lower package of the Higher Himalayan Crystallines (HHC) exposes a small concordant to discordant intrusive grey granite-The Maglad Khad Granite, within garnet mica schist/banded gneiss of the Jeori Formation. This body is fine grained and foliated along the margins, whereas the central part is relatively undeformed. This body along with aplites and pegmatites intrudes the country rock during early to syn-D-1 deformation. This is later affected by the most pervasive D-2-deformation producing gneissosity within the granite. U-Pb dating of zircons by conventional isotopic dilution technique yield an upper intercept age of 2068 +/- 5 Ma (2 sigma) from 6 zircon-fractions with MSWD=0.93, constraining the age of crystallization in the basal parts of the HHC during Early Proterozoic as well as the constraining pre-Himalayan fabric development.
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