| 1. |
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Highlights from the first year of Odin observations
- 2003
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 402, s. L39-L46
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Tidskriftsartikel (refereegranskat)abstract
- Key Odin operational and instrumental features and highlights from our sub-millimetre and millimetre wave observations of H2O, H218O, NH3, 15NH3 and O2 are presented, with some insights into accompanying Odin Letters in this A&A issue. We focus on new results where Odin's high angular resolution, high frequency resolution, large spectrometer bandwidths, high sensitivity or/and frequency tuning capability are crucial: H2O mapping of the Orion KL, W3, DR21, S140 regions, and four comets; H2O observations of Galactic Centre sources, of shock enhanced H2O towards the SNR IC443, and of the candidate infall source IRAS 16293-2422; H218O detections in Orion KL and in comet Ikeya-Zhang; sub-mm detections of NH3 in Orion KL (outflow, ambient cloud and bar) and ρ Oph, and very recently, of 15NH3 in~Orion KL. Simultaneous sensitive searches for the 119 GHz line of O2 have resulted in very low abundance limits, which are difficult to accomodate in chemical models. We also demonstrate, by means of a quantitative comparison of Orion KL H2O results, that the Odin and SWAS observational data sets are very consistently calibrated. Odin is a Swedish-led satellite project funded jointly by the Swedish National Space Board (SNSB), the Canadian Space Agency (CSA), the National Technology Agency of Finland (Tekes), and the Centre National d'études Spatiales (CNES, France). The Swedish Space Corporation (SSC) has been the prime industrial contractor, and is also responsible for the satellite operation from its Odin Mission Control Centre at SSC in Solna and its Odin Control Centre at ESRANGE near Kiruna in northern Sweden. See also the SNSB Odin web page: http://www.snsb.se/eng_odin_intro.shtml
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| 2. |
- Pagani, L., et al.
(författare)
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Low upper limits on the O2 abundance from the Odin satellite
- 2003
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 402, s. L77-L81
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Tidskriftsartikel (refereegranskat)abstract
- For the first time, a search has been conducted in our Galaxy for the 119 GHz transition connecting to the ground state of O2, using the Odin satellite. Equipped with a sensitive 3 mm receiver (Tsys(SSB) = 600 K), Odin has reached unprecedented upper limits on the abundance of O2, especially in cold dark clouds where the excited state levels involved in the 487 GHz transition are not expected to be significantly populated. Here we report upper limits for a dozen sources. In cold dark clouds we improve upon the published SWAS upper limits by more than an order of magnitude, reaching N(O2)/N(H2) <= 10-7 in half of the sources. While standard chemical models are definitively ruled out by these new limits, our results are compatible with several recent studies that derive lower O2 abundances. Goldsmith et al. (\cite{SWAS2002}) recently reported a SWAS tentative detection of the 487 GHz transition of O2 in an outflow wing towards rho Oph A in a combination of 7 beams covering approximately 10arcmin x 14arcmin . In a brief (1.3 hour integration time) and partial covering of the SWAS region (~65% if we exclude their central position), we did not detect the corresponding 119 GHz line. Our 3 sigma upper limit on the O2 column density is 7.3x 1015 cm-2. We presently cannot exclude the possibility that the SWAS signal lies mostly outside of the 9\arcmin Odin beam and has escaped our sensitive detector. Based on observations with Odin, a Swedish-led satellite project funded jointly by the Swedish National Space Board (SNSB), the Canadian Space Agency (CSA), the National Technology Agency of Finland (Tekes) and Centre National d'Études Spatiales (CNES). The Swedish Space Corporation was the industrial prime contractor and is operating Odin.
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| 3. |
- Sandqvist, Aa., et al.
(författare)
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Odin observations of H2O in the Galactic Centre
- 2003
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 402, s. L63-L67
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Tidskriftsartikel (refereegranskat)abstract
- The Odin satellite has been used to detect emission and absorption in the 557-GHz H216O line in the Galactic Centre towards the Sgr Astar Circumnuclear Disk (CND), and the Sgr A +20 km s-1 and +50 km s-1 molecular clouds. Strong broad H2O emission lines have been detected in all three objects. Narrow H2O absorption lines are present at all three positions and originate along the lines of sight in the 3-kpc Spiral Arm, the -30 km s-1 Spiral Arm and the Local Sgr Spiral Arm. Broad H2O absorption lines near -130 km s-1 are also observed, originating in the Expanding Molecular Ring. A new molecular feature (the ``High Positive Velocity Gas'' - HPVG) has been identified in the positive velocity range of ~+120 to +220 km s-1, seen definitely in absorption against the stronger dust continuum emission from the +20 km s-1 and +50 km s-1 clouds and possibly in emission towards the position of Sgr Astar CND. The 548-GHz H218O isotope line towards the CND is not detected at the 0.02 K (rms) level. Based on observations with Odin, a Swedish-led satellite project funded jointly by the Swedish National Space Board (SNSB), the Canadian Space Agency (CSA), the National Technology Agency of Finland (Tekes) and Centre National d'Études Spatiales (CNES). The Swedish Space Corporation was the industrial prime contractor and is also responsible for the satellite operation.
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| 4. |
- Andre, M., Behlke, R., Wahlund, J.E., Vaivads, A., Eriksson, A., Tjulin, A., Carozzi, T. D., Cully, C., Gustafsson, G., Sundkvist, D., Khotyaintsev, Y., Cornilleau-Wehrlin, N., Rezeau, L., Maksimovic, M., Lucek, E., Balogh, A., Dunlop, M., Lindqvist, P.A.
(författare)
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Multi-spacecraft observations of broadband waves near the lower hybrid frequency at the Earthward edge of the magnetopause.
- 2001
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Ingår i: Annales Geophysicae. ; 19:6, s. 1471-1481
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Tidskriftsartikel (refereegranskat)abstract
- Broadband waves around the lower hybrid frequency (around 10 Hz) near the magnetopause are studied, using the four Cluster satellites. These waves are common at the Earthward edge of the boundary layer, consistent with earlier observations, and can have a
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| 5. |
- Andre, M., et al.
(författare)
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Multi-spacecraft observations of broadband waves near the lower hybrid frequency at the Earthward edge of the magnetopause
- 2001
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Ingår i: Annales Geophysicae. - : Copernicus GmbH. - 0992-7689 .- 1432-0576. ; 19:12-okt, s. 1471-1481
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Tidskriftsartikel (refereegranskat)abstract
- Broadband waves around the lower hybrid frequency (around 10 Hz) near the magnetopause are studied, using the four Cluster satellites. These waves are common at the Earthward edge of the boundary layer, consistent with earlier observations, and can have amplitudes at least up to 5 mV/m. These waves are similar on all four Cluster satellites, i.e. they are likely to be distributed over large areas of the boundary. The strongest electric fields occur during a few seconds, i.e. over distances of a few hundred km in the frame of the moving magnetopause, a scale length comparable to the ion gyroradius. The strongest magnetic oscillations in the same frequency range are typically found in the boundary layer, and across the magnetopause. During an event studied in detail, the magnetopause velocity is consistent with a large-scale depression wave, i.e. an inward bulge of magnetosheath plasma, moving tailward along the nominal magnetopause boundary. Preliminary investigations indicate that a rather flat front side of the large-scale wave is associated with a rather static small-scale electric field, while a more turbulent backside of the large-scale wave is associated with small-scale time varying electric field wave packets.
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| 6. |
- Bergqvist, D, et al.
(författare)
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Haverikommission granskade karotiskirurgins komplikationer. Hälften kunde förklaras med misstag eller tveksamma indikationer
- 2000
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Ingår i: Läkartidningen. - 0023-7205. ; 97:14, s. 1673-1676
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Tidskriftsartikel (refereegranskat)abstract
- As carotid endarterectomy is a prophylactic procedure, it would seem particularly important to analyze complications with an aim to avoiding them. All carotid endarterectomies in Sweden are registered, and all serious complications (death and permanent neurological deficit) are analyzed in detail, classified and discussed within the profession. During the period 1994-1996 the frequency was 4.3 percent (technical causes in 17 percent, contraindications in 8 percent and dubious indications in 21 percent, but correct indication and surgery in 54 percent). Thus, even when conditions are optimal there is a certain price to pay for the prevention of ischemic stroke.
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| 7. |
- Marklund, G.T., Ivchenko, N., Karlsson, T., Fazakerley, A., Dunlop, M., Lindqvist, P.A., Buchert, S., Owen, C., Taylor, M., Vaivalds, A., Carter, P., Andre, M. and Balogh, A.
(författare)
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Temporal evolution of the electric field accelerating electrons away from the auroral ionosphere.
- 2001
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Ingår i: Nature. ; 414:6865, s. 724-727
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Tidskriftsartikel (refereegranskat)abstract
- The bright night-time aurorae that are visible to the unaided eye are caused by electrons accelerated towards Earth by an upward-pointing electric field(1-3). On adjacent geomagnetic field lines the reverse process occurs: a downward-pointing electric fie
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| 8. |
- Marklund, Göran T., et al.
(författare)
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Temporal evolution of the electric field accelerating electrons away from the auroral ionosphere
- 2001
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 414:6865, s. 724-727
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Tidskriftsartikel (refereegranskat)abstract
- The bright night-time aurorae that are visible to the unaided eye are caused by electrons accelerated towards Earth by an upward-pointing electric field(1-3). On adjacent geomagnetic field lines the reverse process occurs: a downward-pointing electric field accelerates electrons away from Earth(4-11). Such magnetic-field-aligned electric fields in the collisionless plasma above the auroral ionosphere have been predicted(12), but how they could be maintained is still a matter for debate(13). The spatial and temporal behaviour of the electric fields-a knowledge of which is crucial to an understanding of their nature-cannot be resolved uniquely by single satellite measurements. Here we report on the first observations by a formation of identically instrumented satellites crossing a beam of upward-accelerated electrons. The structure of the electric potential accelerating the beam grew in magnitude and width for about 200 s, accompanied by a widening of the downward-current sheet, with the total current remaining constant. The 200-s timescale suggests that the evacuation of the electrons from the ionosphere contributes to the formation of the downward-pointing magnetic-field-aligned electric fields. This evolution implies a growing load in the downward leg of the current circuit, which may affect the visible discrete aurorae.
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| 9. |
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| 10. |
- Wahlgren, N G, et al.
(författare)
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Multidisciplinärt samarbete bakom kvalitetsregister för karotiskirurgi. God täckningsgrad under de första två verksamhetsåren
- 2000
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Ingår i: Läkartidningen. - 0023-7205. ; 97:14, s. 1678-1678
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Tidskriftsartikel (refereegranskat)abstract
- Carotid surgery prevents recurrent stroke in patients with symptomatic tight stenosis of the carotid artery. The Swedish Carotid Surgery Monitoring Registry seeks to promote selection of patients with significant spontaneous risk for recurrent stroke, with an eye toward expediting evaluation and minimizing surgical complications. To this end, professionals at participating hospitals are informed about their own patient selection and surgery risk in comparison with those in the country as a whole and with set targets. We report the results from the first two years, during which it is estimated that more than half of all patients eligible for carotid surgery in Sweden were included in the registry. Although almost all patients had recent onset of relevant neurological symptoms, less than 60% had a documented tight (80-99% occlusion) stenosis. While the final decision to operate a patient was made within 4 weeks of onset of symptoms for only 18% of the patients the first year, this proportion increased to 33% in the following year. The total incidence of surgery related stroke, myocardial infarct and death was 7.7%, while the incidence of severe stroke, myocardial infarct and death was 3.0%.
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| 11. |
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| 12. |
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| 13. |
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| 14. |
- Dellborg, M, et al.
(författare)
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Changes in the use of medication after acute myocardial infarction : Possible impact on post-myocardial infarction mortality and long-term outcome
- 2001
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Ingår i: Coronary Artery Disease. - : Lippincott Williams & Wilkins. - 0954-6928 .- 1473-5830. ; 12:1, s. 61-67
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To describe the change in the use of medication after acute myocardial infarction (AMI) and discuss its possible impact on risk and risk indicators for death. Patients: All patients discharged alive after hospitalization for AMI at Sahlgrenska Hospital (covering half the community of Goteborg, i.e. 250 000 of 500 000 inhabitants) during 1986-1987 (period I) and at Sahlgrenska Hospital and Ostra Hospital (covering the whole community of Goteborg, 500 000 inhabitants) during 1990-1991 (period II). Methods: Overall mortality was retrospectively evaluated during 5 years of follow-up. Results: In all, 740 patients were included in the study during period I and 1448 during period II. The 5-year mortalities were 44.1% for period I patients and 39.3% for period II patients (P = 0.036). The relative risk of death for period II patients was 0.78 [95% confidence interval (CI) 0.67-0.89, P = 0.0005] after adjustment for differences at baseline. There was a significant interaction with a history of congestive heart failure; improvement in duration of survival was found only for patients without such a history. During period I, only 3% of patients were administered fibrinolytic agents, compared with 33% of patients during period II (P < 0.0001). During period I, aspirin was prescribed for 13% of patients discharged from hospital compared with 79% during period II. Other changes in treatment on going from period I to period II included increases in prescription of [beta]-blockers and angiotensin converting enzyme inhibitors. After adjustment for various risk indicators for death, relative risk of death for those administered fibrinolytic agents was 0.60 (95% CI 0.18-2.02) for patients in the period-I cohort and 0.68% (95% CI 0.51-0.91) for those in the period-II cohort. Adjusted relative risk of death for those prescribed aspirin upon discharge from hospital was 0.81 (95% CI 0.52-1.25) for period-I patients and 0.71 (95% CI 0.56-0.91) for period-II patients. The adjusted relative risk of death for those administered [beta]-blockers was 0.72 (95% CI 0.55-0.96) for period-I patients and 0.70 (95% CI 0.55-0.90) for period-II patients. Conclusion: Increased use of fibrinolytic agents and aspirin for AMI as well as a moderate increase in use of [beta]-blockers and angiotensin converting enzyme inhibitors was associated with a parallel reduction in age-adjusted mortality during the 5 years after discharge from hospital. However, this improvement was seen only for patients without histories of congestive heart failure.
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| 15. |
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| 16. |
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| 17. |
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| 18. |
- Marklund, Göran T., et al.
(författare)
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Characteristics of quasi-static potential structures observed in the auroral return current region by Cluster
- 2004
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Ingår i: Nonlinear processes in geophysics. - : Copernicus GmbH. - 1023-5809 .- 1607-7946. ; 11:5-6, s. 709-720
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Tidskriftsartikel (refereegranskat)abstract
- Temporal and spatial characteristics of intense quasi-static electric fields and associated electric potential structures in the return current region are discussed using Cluster observations at geocentric distances of about 5 Earth radii. Results are presented from four Cluster encounters with such acceleration structures to illustrate common as well as different features of such structures. The electric field structures are characterized by (all values are projected to 100 cm altitude) peak amplitudes of approximate to 1V/m, bipolar or unipolar profiles, perpendicular scale sizes of approximate to 10km, occurrence at auroral plasma boundaries associated with plasma density gradients, downward field-aligned currents of approximate to 10 muA/m(2), and upward electron beams with characteristic energies of a few hundred eV to a few keV. Two events illustrate he temporal evolution of bipolar, diverging electric field strictures, indicative of positive U-shaped potentials increasing in magnitude from less than 1 kV to a few kV on a few 100s time scale. This is also the typical formation time for ionospheric plasma cavities, which are connected to the potential structure and suggested to evolve hand-in-hand with these. In one of these events an energy decay of inverted-V ions was observed in the upward field-aligned current region prior to the acceleration potential increase in the adjacent downward current region, possibly suggesting that a potential redistribution took place between the two current branches. The other two events were characterized by intense unipolar electric fields, indicative of S-shaped potential contours and were encountered at the polar cap boundary. The total observation time for these events was typically 10-20 s, too short for monitoring the evolution of the structure, bui yet of interest for revealing their short term stability. The locations of the two bipolar events at the poleward boundary of the central plasma sheet and of the two unipolar events at the polar cap boundary, suggest that the special profile shape depends on whether plasma populations, dense enough to support upward field-aligned currents and closure of the return current, exist on both sides, or on one side only, of the boundary.
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| 19. |
- Roobol-Boza, M, et al.
(författare)
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Membrane protein isolation by in situ solubilization, partitioning and affinity adsorption in aqueous two-phase systems - Purification of the human type 1 11 beta-hydroxysteroid dehydrogenase
- 2004
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Ingår i: Journal of Chromatography A. - : Elsevier BV. - 0021-9673. ; 1043:2, s. 217-223
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Tidskriftsartikel (refereegranskat)abstract
- Recently developed aqueous two-phase systems based on non-ionic detergents and polymers are suitable for the separation of membrane proteins. Moreover, within this relatively membrane protein "friendly" environment, changes in temperature can be controlled and stabilizing agents may be added to ensure integrity of the target protein during isolation. Here, we use aqueous two-phase partitioning for the isolation of membrane bound I I p-hydroxysteroid dehydrogenase type I (11beta-HSD1). Different detergents were used to find optimal conditions regarding solubilization and retaining target protein activity. We explored in situ solubilization by adding detergent directly to the aqueous two-phase system, as well as a batch metal affinity capture step of 6xHis tagged 11beta-HSD1 in the two-phase system. The use of detergent/polymer two-phase systems resulted in a specific enzyme activity of 3840 nmol mg(-1) min(-1) of the target membrane protein compared to a conventional purification protocol where a specific enzyme activity of 1440 nmol mg(-1) min(-1) was achieved. (C) 2004 Elsevier B.V. All rights reserved.
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| 20. |
- van Kuilenburg, André B P, et al.
(författare)
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Novel disease-causing mutations in the dihydropyrimidine dehydrogenase gene interpreted by analysis of the three-dimensional protein structure
- 2002
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Ingår i: Biochemical Journal. - : Portland Press Ltd.. - 0264-6021 .- 1470-8728. ; 364:Pt 1, s. 157-163
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Tidskriftsartikel (refereegranskat)abstract
- Dihydropyrimidine dehydrogenase (DPD) deficiency is an autosomal recessive disease characterized by thymine-uraciluria in homozygous deficient patients. Cancer patients with a partial deficiency of DPD are at risk of developing severe life-threatening toxicities after the administration of 5-fluorouracil. Thus, identification of novel disease-causing mutations is of the utmost importance to allow screening of patients at risk. In eight patients presenting with a complete DPD deficiency, a considerable variation in the clinical presentation was noted. Whereas motor retardation was observed in all patients, no patients presented with convulsive disorders. In this group of patients, nine novel mutations were identified including one deletion of two nucleotides [1039-1042delTG] and eight missense mutations. Analysis of the crystal structure of pig DPD suggested that five out of eight amino acid exchanges present in these patients with a complete DPD deficiency, Pro86Leu, Ser201Arg, Ser492Leu, Asp949Val and His978Arg, interfered directly or indirectly with cofactor binding or electron transport. Furthermore, the mutations Ile560Ser and Tyr211Cys most likely affected the structural integrity of the DPD protein. Only the effect of the Ile370Val and a previously identified Cys29Arg mutation could not be readily explained by analysis of the three-dimensional structure of the DPD enzyme, suggesting that at least the latter might be a common polymorphism. Our data demonstrate for the first time the possible consequences of missense mutations in the DPD gene on the function and stability of the DPD enzyme.
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| 21. |
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| 22. |
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| 23. |
- Blomberg, Lars G., et al.
(författare)
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EMMA - the electric and magnetic monitor of the aurora on Astrid-2
- 2004
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Ingår i: Annales Geophysicae. - : Copernicus GmbH. - 0992-7689 .- 1432-0576. ; 22:1, s. 115-123
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Tidskriftsartikel (refereegranskat)abstract
- The Astrid-2 mission has dual primary objectives. First, it is an orbiting instrument platform for studying auroral electrodynamics. Second, it is a technology demonstration of the feasibility of using micro-satellites for innovative space plasma physics research. The EMMA instrument, which we discuss in the present paper, is designed to provide simultaneous sampling of two electric and three magnetic field components up to about 1 kHz. The spin plane components of the electric field are measured by two pairs of opposing probes extended by wire booms with a separation distance of 6.7 m. The probes have titanium nitride (TiN) surfaces. which has proved to be a material with excellent properties for providing good electrical contact between probe and plasma. The wire booms are of a new design in which the booms in the stowed position are wound around the exterior of the spacecraft body. The boom system was flown for the first time on this mission and worked flawlessly. The magnetic field is measured by a tri-axial fluxgate sensor located at the tip of a rigid. hinged boom extended along the spacecraft spin axis and facing away from the Sun. The new advanced-design fluxgate magnetometer uses digital signal processors for detection and feedback, thereby reducing the analogue circuitry to a minimum. The instrument characteristics as well as a brief review of the science accomplished and planned are presented.
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| 24. |
- Blomberg, Lars G., et al.
(författare)
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Solar windmagnetosphere-ionosphere coupling : an event study based on Freja data
- 2004
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Ingår i: Journal of Atmospheric and Solar-Terrestrial Physics. - : Elsevier BV. - 1364-6826 .- 1879-1824. ; 66:5, s. 375-380
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Tidskriftsartikel (refereegranskat)abstract
- Freja data are used to study the relative contributions from the high-latitude (reconnection/direct entry) and low-latitude (viscous interaction) dynamos to the cross-polar potential drop. Convection streamlines which are connected to the high-latitude dynamo may be identified from dispersed magnetosheath ions not only in the cusp/cleft region itself but also several degrees poleward of it. This fact, together with Freja's orbital geometry allows us to infer the potential drop from the high-latitude dynamo as well as to obtain a lower limit to the potential drop from the low-latitude dynamo for dayside Freja passes. All cases studied here are for active magnetospheric conditions. The Freja data suggest that under these conditions at least one third of the potential is generated in the low-latitude dynamo. These observations are consistent with earlier observations of the potential across the low-latitude boundary layer if we assume that the low-latitude dynamo region extends over several tens of Earth radii in the antisunward direction along the tail flanks, and that the majority of the potential drop derives from the sun-aligned component of the electric field rather than from its cross-boundary component, or equivalently, that the centre of the dynamo region is located quite far down tail. A possible dynamo geometry is illustrated.
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| 25. |
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