| 1. |
- Castro-Tirado, A. J., et al.
(författare)
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GRB 030227 : The first multiwavelength afterglow of an INTEGRAL GRB
- 2003
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Ingår i: Astronomy & Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 411:1, s. 315-319
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Tidskriftsartikel (refereegranskat)abstract
- We present multiwavelength observations of a gamma-ray burst detected byINTEGRAL (GRB 030227) between 5.3 hours and ~ 1.7days after the event. Here we report the discovery of a dim opticalafterglow (OA) that would not have been detected by many previoussearches due to its faintess (R ~ 23). This OA was seen to declinefollowing a power law decay with index alpha R = -0.95 +/-0.16. The spectral index beta_ opt/NIR yielded -1.25 +/- 0.14. Thesevalues may be explained by a relativistic expansion of a fireball (withp = 2.0) in the cooling regime. We also find evidence for inverseCompton scattering in X-rays.Based on observations with INTEGRAL, an ESA project with instruments andscience data centre funded by ESA member states (especially the PIcountries: Denmark, France, Germany, Italy, Switzerland, Spain), CzechRepublic and Poland, and with the participation of Russia and the USA.Also partially based on observations collected by the Gamma-Ray BurstCollaboration at ESO (GRACE) at the European Southern Observatory, Chile(ESO Large Programme 165.H-0464).
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| 2. |
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| 3. |
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| 4. |
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| 5. |
- Thunes, KH, et al.
(författare)
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The arthropod community of Scots pine (Pinus sylvestris L.) canopies in Norway
- 2004
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Ingår i: Entomologica Fennica. - 0785-8760. ; 15:2, s. 65-90
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Forskningsöversikt (refereegranskat)abstract
- We summarise the findings of arthropods collected by fogging the canopy of 24 pine trees in two sites in Eastern and Western Norway. From the samples, taken in 1998 and in 1999, almost 30,000 specimens were determined to 512 species, with Diptera being most species rich (210 species), followed by Coleoptera (76 species) and Araneae (49 species). Of the 96 new species records, nine were new to science (5 Diptera and 4 Oribatida), two were new to the European, three to the Scandinavian and 82 to the Norwegian faunas. The paper demonstrates the need for detailed faunistical inventories of European forests.
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| 6. |
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| 7. |
- Ottesen, G L, et al.
(författare)
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Carcinoma in situ of the breast: correlation of histopathology to immunohistochemical markers and DNA ploidy
- 2000
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Ingår i: Breast Cancer Research and Treatment. - 1573-7217. ; 60:3, s. 219-226
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Tidskriftsartikel (refereegranskat)abstract
- In a consecutive and unselected series of 178 cases of carcinoma in situ of the breast (CIS), comprising both ductal (DCIS) and lobular type (LCIS), and a series of 48 cases of invasive carcinoma (IC) with predominance of DCIS, the association between histopathology, immunohistochemical markers (ER, PgR, MIB-1, c-erbB-2, and p53), and DNA ploidy was investigated, in order to discriminate biologically different groups. In DCIS, significant correlation was shown between large nuclear size and comedonecrosis, both of which showed also strong association to DNA aneuploidy, high proliferation activity, low steroid receptor content, and overexpression of c-erbB-2 and p53 factors that may indicate an aggressive behavior. Small nuclear CIS, whether LCIS or DCIS, on the contrary, were DNA diploid with low proliferation, and no cases showed overexpression of c-erbB-2 and p53. Heterogeneity with respect to the investigated parameters was also a frequent finding that may reflect a development complexity. In IC, comparison of the DCIS and the invasive component showed similar patterns. No significant differences were shown between DCIS without and with invasion. This may indicate that none of the investigated parameters on its own are essential for the event of invasion.
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| 8. |
- Smith, P B, et al.
(författare)
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Cultural values, sources of guidance, and their relevance to managerial behavior - A 47-nation study
- 2002
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Ingår i: Journal of Cross-Cultural Psychology. - : Sage Publications. - 0022-0221 .- 1552-5422. ; 33:2, s. 188-208
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Tidskriftsartikel (refereegranskat)abstract
- Data are presented showing how middle managers in 47 countries report handling eight specific work events. The data are used to test the ability of cultural value dimensions derived from the work of Hofstede. Trompenaars, and Schwartz to predict the specific sources of guidance on which managers rely. Focusing on sources of guidance is expected to provide a more precise basis than do generalized measures of values for understanding the behaviors that prevail within different cultures. Values are strongly predictive of reliance on those sources of guidance that are relevant to vertical relationships within organizations. Hock ever, values are less successful in predicting reliance on peers and on more tacit sources of guidance. Explaining national differences in these neglected aspects of organizational processes will require greater sensitivity to the culture-specific contexts within which they occur.
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| 9. |
- Andersen, JR, et al.
(författare)
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Small-x phenomenology - summary and status 2002
- 2004
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 35:1, s. 67-98
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Forskningsöversikt (refereegranskat)abstract
- A second workshop on small-x physics, within the Small-x Collaboration, was held in Lund in June 2002 with the aim of over-viewing recent theoretical progress in this area and summarizing the experimental status.
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| 10. |
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| 11. |
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| 12. |
- Svedman, Cecilia, et al.
(författare)
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Deodorants: an experimental provocation study with hydroxycitronellal.
- 2003
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873. ; 48:4, s. 217-223
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Tidskriftsartikel (refereegranskat)abstract
- Axillary dermatitis is a common problem, particularly in individuals with contact allergy to fragrances. Many individuals suspect their deodorant to be the causal product of their fragrance allergy. It has been shown that deodorants containing cinnamic aldehyde (cinnamal) can elicit axillary dermatitis in patients sensitized to this substance. The aim of the present investigation was to evaluate the importance of hydroxycitronellal used in deodorants for the development of axillary dermatitis, when applied by individuals with and without contact allergy to this fragrance chemical. Patch tests with deodorants and ethanolic solutions containing hydroxycitronellal, as well as repeated open application tests (ROAT) with roll-on deodorants with and without hydroxycitronellal at different concentrations, were performed in 14 dermatitis patients, 7 with and 7 without contact allergy to hydroxycitronellal. A positive ROAT was noted only in the patients hypersensitive to hydroxycitronellal (P < 0·001) and only in the axilla to which the deodorants containing hydroxycitronellal had been applied (P < 0·001). Deodorants containing hydroxycitronellal in the concentration range of 0·032–0·32% used twice daily on healthy skin in individuals hypersensitive to hydroxycitronellal can elicit axillary dermatitis in a few weeks.
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| 13. |
- Agner, T, et al.
(författare)
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Standardization of the TRUE Test imidazolidinyl urea and diazolidinyl urea patches
- 2001
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873. ; 45:1, s. 21-25
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Tidskriftsartikel (refereegranskat)abstract
- The preservatives imidazolidinyl urea (IMID, Germall 115) and diazolidinyl urea (DU, Germall II) are commonly used in cosmetic products and are well-known sensitizers. The aim of the present study was to establish the optimal patch test concentration in hydrophilic dried-in vehicle (TRUE Test) for IMID and DU. 181 patients were included in the study. Of these, 150 were patients referred for patch testing, 12 were patients with known allergy to IMID and 19 were patients with known allergy to DU. 76 consecutive patients and the 12 IMID-allergic patients were patch tested with a dilution series IMID (0 to 600 microg/cm(2)), formaldehyde (180 microg/cm(2)) and DU (200 microg/cm(2)). 74 consecutive patients and the 19 DU-allergic patients were patch tested with a dilution series of DU (0 to 600 microg/cm(2)), formaldehyde (180 microg/cm) and IMID (200 microg/cm(2)). A positive dose-response relationship was found. The number of doubtful reactions decreased with increasing test concentrations. No late reactions were observed. A patch test concentration in hydrophilic dried-in vehicle (TRUE Test) of 600 microg/cm(2) was found to be adequate and safe for both IMID and DU.
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| 14. |
- Akesson, E, et al.
(författare)
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A genome-wide screen for linkage in Nordic sib-pairs with multiple sclerosis
- 2002
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Ingår i: Genes and Immunity. - : Springer Science and Business Media LLC. - 1476-5470 .- 1466-4879. ; 3:5, s. 279-285
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Tidskriftsartikel (refereegranskat)abstract
- Genetic factors influence susceptibility to multiple sclerosis but the responsible genes remain largely undefined, association with MHC class II alleles being the only established genetic feature of the disease. The Nordic countries have a high prevalence of multiple sclerosis, and to further explore the genetic background of the disease, we have carried out a genome-wide screen for linkage in 136 sibling-pairs with multiple sclerosis from Denmark, Finland, Norway and Sweden by typing 399 microsatellite markers. Seventeen regions where the lod score exceeds the nominal 5% significance threshold (0.7) were identified-1q11-24, 2q24-32, 3p26.3, 3q21.1, 4q12, 6p25.3, 6p21-22, 6q21, 9q34.3, 10p15, 10p12-13, 11p15.5, 12q21.3, 16p13.3, 17q25.3, 22q12-13 and Xp22.3. Although none of these regions reaches the level of genome-wide significance, the number observed exceeds the 10 that would be expected by chance alone. Our results significantly add to the growing body of linkage data relating to multiple sclerosis.
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| 15. |
- Andersen, Torben, et al.
(författare)
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Euro50
- 2003
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Ingår i: Proceedings of the SPIE - The International Society for Optical Engineering. - : SPIE. - 1996-756X .- 0277-786X. ; 5382:1, s. 169-182
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Konferensbidrag (refereegranskat)abstract
- The Euro50 is a telescope for optical and infrared wavelengths. It has an aspherical primary mirror with a size of 50 meters and 618 segments. The optical configuration is of Gregorian type and the secondary mirror is deformable for adaptive optics. Observations can take place in prime focus, Gregorian foci, and Nasmyth foci using additional relay mirrors. The telescope provides seeing limited observations, partial adaptive optics with ground layer correction, single conjugate adaptive optics and dual-conjugate adaptive optics. For prime focus observations, a clam-shell corrector with a doublet lens is used. The primary mirror segments can be polished using the precessions polishing technique. "Live Optics" denotes the joint segment alignment system, secondary mirror control system, adaptive optics and main axes servos. An overview is given of the live optics architecture, including feedback from wavefront sensors for natural and laser guide stars, and from primary mirror segment edge sensors. A straw man concept of the laser guide star system using sum-frequency YAG lasers is presented together with a solution to the laser guide star perspective elongation problem. The structural design involves a large steel structure and a tripod of carbon fiber reinforced polymer to support the secondary mirror. Integrated models have been set up to simulate telescope performance. Results show that an enclosure is needed to protect the telescope against wind during observations. The enclosure is very large box-shaped steel structure
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| 16. |
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| 17. |
- Balogh, Istvan, et al.
(författare)
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Questionnaire-based mechanical exposure indices for large population studies--reliability, internal consistency and predictive validity
- 2001
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Ingår i: Scandinavian Journal of Work, Environment and Health. - 0355-3140. ; 27:1, s. 41-41
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: This study attempts to construct valid indices for mechanical exposure of the shoulder-neck region with relation to the development of shoulder-neck pain in a 1-year perspective study of a general population. METHODS: A comprehensive questionnaire was presented to 14 556 subjects aged 45 or 65 years and repeated after 12 months. Twenty-four questions concerning positions, movements, and manual materials handling were registered on a 3-point impact scale. Musculoskeletal problems were reported on a slightly modified version of the Standardized Nordic Questionnaire for the Analysis of Musculoskeletal Symptoms. Test-retest stability after 2 weeks was calculated for 232 consecutive participants. Based on mechanistic theories, 4 exposure indices were formed. Another 5 constructs were obtained by factor analysis. RESULTS: All the indices showed good test-retest stability, and 5 of them had very good internal consistency. Due to overlaps between the indices, 2 indices stood out as having unique properties. One of them concerned mainly postures and the other dealt primarily with measured lifting. However, the latter was not related to the shoulder-neck pain outcome when adjusted for the posture index. The posture index showed an exposure-effect relationship with the outcome. The job titles implied a large degree of exposure misclassification. CONCLUSIONS: The posture index is recommended as a mechanical exposure index for analyses of interaction with other possible determinants of shoulder-neck pain (ie, psychosocial factors). The use of such an index instead of job titles in large population studies will reduce the risk of misclassification.
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| 18. |
- Beutler, A., et al.
(författare)
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Identification of a laterally mobile state during CO adsorption
- 2000
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Ingår i: Journal of Physics: Condensed Matter. - : IOP Publishing. - 0953-8984 .- 1361-648X. ; 12:6, s. 765-772
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated CO adsorption at 300 K on ∼ 1.5 atomic layer thick Pd films on a Mo(110) surface by high-resolution core level photoemission. We describe how high-resolution core level spectroscopy may be utilized to study the influence of laterally mobile states on the sticking probability of molecules on such a laterally heterogeneous surface. The present Pd films are laterally heterogeneous in the sense that the additional ∼ 0.5 atomic Pd layer forms mesoscopic one-layer thick islands on top of the first Pd layer. At 300 K, CO chemisorbs on these two-layer thick islands but not on the one-layer parts of the film. The rate at which these two-layer islands are filled by CO molecules as the surface is exposed to CO is found to be consistent with a picture where CO molecules that initially impinge on the one-layer parts of the surface enter a laterally mobile state and diffuse to the two-layer islands and adsorb there. This mobile state is in many respects similar to a classical precursor state.
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| 19. |
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| 20. |
- Hansen, S, et al.
(författare)
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Independent prognostic value of angiogenesis and the level of plasminogen activator inhibitor type I in breast cancer patients
- 2003
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Ingår i: British Journal of Cancer. - : Springer Science and Business Media LLC. - 1532-1827 .- 0007-0920. ; 88:1, s. 102-108
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Tidskriftsartikel (refereegranskat)abstract
- Tumour angiogenesis and the levels of plasminogen activator inhibitor type I (PAI-I) are both informative prognostic markers in breast cancer. In cell cultures and in animal model systems, PAI-I has a proangiogenic effect. To evaluate the interrelationship of angiogenesis and the PAI-I level in breast cancer, we have evaluated the prognostic value of those factors in a total of 228 patients with primary, unilateral, invasive breast cancer, evaluated at a median follow-up time of 12 years. Microvessels were immunohistochemically stained by antibodies against CD34 and quantitated by the Chalkley counting technique. The levels of PAI-I and its target proteinase uPA in tumour extracts were analysed by ELISA. The Chalkley count was not correlated with the levels of uPA or PAI-I. High values of uPA, PAI-I, and Chalkley count were all significantly correlated with a shorter recurrence-free survival and overall survival. In the multivariate analysis, the uPA level did not show independent prognostic impact for any of the analysed end points. In contrast, the risk of recurrence was independently and significantly predicted by both the PAI-I level and the Chalkley count, with a hazard ratio (95% CI) of 1.6 (1.01-2.69) and 1.4 (1.02-1.81), respectively. For overall survival, the Chalkley count, but not PAI-I, was of significant independent prognostic value. The risk of death was 1.7 (1,30-2.15) for Chalkley counts in the upper tertile compared to the lower one. We conclude that the PAI-I level and the Chalkley count are independent prognostic markers for recurrence-free survival in patients with primary breast cancer, suggesting that the prognostic impact of PAI-I is not only based on its involvement in angiogenesis. (C) 2003 Cancer Research UK.
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| 21. |
- Hoy, M, et al.
(författare)
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Imidazoline NNC77-0074 stimulates insulin secretion and inhibits glucagon release by control of Ca2+-dependent exocytosis in pancreatic alpha- and beta-cells
- 2003
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Ingår i: European Journal of Pharmacology. - 1879-0712. ; 466:1-2, s. 213-221
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated the effects of the novel imidazoline compound (+)-2-(2-(4,5-dihydro-1H-imidazol-2-yl)-thiopene-2-yl-ethyl)pyridine (NNC77-0074) on stimulus-secretion coupling in isolated pancreatic alpha- and beta-cells. NNC77-0074 stimulated glucose-dependent insulin secretion in intact mouse pancreatic islets. No effect was observed at less than or equal to 2.5 mM glucose and maximal stimulation occurred at 10-15 mM glucose. NNC77-0074 produced a concentration-dependent stimulation of insulin secretion. Half-maximal (EC50) stimulation was observed at 24 muM and at maximally stimulatory concentrations insulin release was doubled. The stimulatory action of NNC77-0074 on insulin secretion was not associated with membrane depolarisation or a change in the activity of ATP-sensitive K+ channels. Using capacitance measurements, we found that NNC77-0074 stimulated depolarisation-induced exocytosis 2.6-fold without affecting the whole-cell Ca2+ current when applied via the extracellular medium. The concentration dependence of the stimulatory action was determined by intracellular application of NNC77-0074 through the recording pipette. NNC77-0074 stimulated exocytosis half-maximal at 44 nM and at maximally stimulatory concentrations the rate of exocytosis was increased twofold. NNC77-0074 stimulated depolarised-induced insulin secretion from islets exposed to diazoxide and high external KCl (EC50 = 0.45 muM). The stimulatory action of NNC77-0074 was dependent on protein kinase C activity. NNC77-0074 potently inhibited glucagon secretion from rat islets (EC50 = I I nM). This was not associated with a change in spontaneous electrical activity and ATP-sensitive K channel activity but resulted from a reduction of the rate of Ca2+-dependent exocytosis in single rat alpha-cells (EC50=9 nM). Inhibition of exocytosis by NNC77-0074 was pertussis toxin-sensitive and mediated by activation of the protein phosphatase calcineurin. In rat somatotrophs, PC12 cells and mouse cortical neurons NNC77-0074 did not stimulate Ca2+-evoked exocytosis, whereas the other imidazoline compounds phentolamine and efaroxan produced 2.5-fold stimulation of exocytosis. Our data suggest that the imidazoline compound NNC77-0074 constitutes a novel class of antidiabetic compounds that stimulates glucose-dependent insulin release while inhibiting glucagon secretion. These actions are exclusively exerted by modulation of exocytosis of the insulin- and glucagon-containing granules. (C) 2003 Elsevier Science B.V. All rights reserved.
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| 22. |
- Ivarsson, Stefan, et al.
(författare)
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Improved oscillator strengths and wavelengths for Os I and Ir I, and new results on early r-process nucleosynthesis
- 2003
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Ingår i: Astronomy & Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 409:3, s. 1141-1149
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Tidskriftsartikel (refereegranskat)abstract
- The radioactive decay of 238U and 232Th has recently been used to determine ages for some of the oldest stars in the Universe. This has highlighted the need for accurate observational constraints on production models for the heaviest r-process elements which might serve as stable references, notably osmium and iridium. In order to provide a firmer basis for the observed abundances, we have performed laser-induced fluorescence measurements and Fourier Transform Spectroscopy to determine new radiative lifetimes and branching fractions for selected levels in Os I and Ir I. From these data, we determine new absolute oscillator strengths and improved wavelengths for18 Os I and 4 Ir I lines. A reanalysis of VLT spectra of CS 31082-001and new results for other stars with Os and Ir detections show that (i):the lines in the UV and lambda 4260 yield reliable Os abundances, while those at lambda lambda 4135, 4420 are heavily affected by blending; (ii): the Os and Ir abundances are identical in all the stars; (iii): the heavy-element abundances in very metal-poor stars conform closely to the scaled solar r-process pattern throughout the range 56 <= Z <= 77; and (iv): neither Os or Ir nor any lighter species are suitable as reference elements for the radioactive decay of Th and U.Based in part on observations obtained with the Very Large Telescope of the European Southern Observatory at Paranal, Chile.
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| 23. |
- Levitz, D, et al.
(författare)
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Determination of optical scattering properties of highly-scattering media in optical coherence tomography images
- 2004
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Ingår i: Optics Express. - 1094-4087. ; 12:2, s. 249-259
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Tidskriftsartikel (refereegranskat)abstract
- We developed a new algorithm that fits optical coherence tomography (OCT) signals as a function of depth to a general theoretical OCT model which takes into account multiple scattering effects. With use of this algorithm, it was possible to extract both the scattering coefficient and anisotropy factor from a particular region of interest in an OCT image. The extraction algorithm was evaluated against measurements from an integrating sphere on a set of tissue phantoms and yielded valid results. Finally, a preliminary ex vivo OCT investigation on human aortic specimen indicated that the algorithm may contribute importantly to differentiation between normal and atherosclerotic arteries. We conclude that this algorithm may facilitate tissue characterization by OCT. (C) 2004 Optical Society of America.
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| 24. |
- Lundgren, Edvin, et al.
(författare)
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Geometry of the valence transition induced surface reconstruction of Sm(0001).
- 2002
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Ingår i: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 88:13, s. 136102-136102
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Tidskriftsartikel (refereegranskat)abstract
- We present a structural determination of the surface reconstruction of the Sm(0001) surface using surface x-ray diffraction, scanning tunneling microscopy, and ab initio calculations. The reconstruction is associated with a large (22%) expansion of the atomic radius for the top monolayer surface Sm atoms. The mechanism driving the surface reconstruction in Sm is unique among all elements and is connected to the strong correlations of the 4f electrons in Sm and the intermediate valence observed in certain Sm compounds. The atoms constituting the top monolayer of Sm(0001) have vastly different chemical properties compared to the layer underneath and behave as if they were an adsorbate of a different chemical species.
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| 25. |
- Mikkelsen, Anders, et al.
(författare)
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A study of the surface structure and composition of annealed Ga0.96Mn0.04As(100)
- 2004
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Ingår i: Applied Surface Science. - 1873-5584. ; 222:1-4, s. 23-32
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Tidskriftsartikel (refereegranskat)abstract
- The surface structure and chemical composition of annealed Ga0.96Mn0.04As(1 0 0) have been studied by scanning tunneling microscopy (STM), auger electron spectroscopy (AES) and low energy electron diffraction (LEED). The samples were As capped and subsequently transferred in-air from the MBE system to the STM chamber. After annealing to 600 K it is found that the Mn segregates to the surface and forms a compound, which is stable up to annealing temperatures of 790 K. For annealing temperatures above 825 K a well-ordered phase exists signified by a LEED pattern consisting of a superposition of a (1 x 6) and a (4 x 2) pattern. LEED and STM measurements demonstrate that the surface is dominated by (1 x 6) domains coexisting with small patches of (4 x 2) domains. By comparing the STM images of the high temperature phase found on Ga0.96Mn0.04As(1 0 0) with the high temperature phases found on ordinary GaAs(1 0 0), we demonstrate differences between annealed Ga0.96Mn0.04As(1 0 0) and GaAs(1 0 0) in both surface morphology and atomic structure. We argue that the Ga0.96Mn0.04As surface is more As rich than the GaAs surface prepared in a similar fashion. Reasons for these differences are discussed.
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| 26. |
- Montalescot, G, et al.
(författare)
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Recommendations on percutaneous coronary intervention for the reperfusion of acute ST elevation myocardial infarction.
- 2004
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Ingår i: Heart (British Cardiac Society). - 1468-201X. ; 90:6
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Forskningsöversikt (refereegranskat)abstract
- Little information is currently available from the various societies of cardiology on primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI). Since primary PCI is the main method of reperfusion in AMI in many centres, and since of all cardiac emergencies AMI represents the most urgent situation for PCI, recommendations based on scientific evidence and expert experience would be useful for centres practising primary PCI, or those looking to establish a primary PCI programme. To this aim, a task force for primary PCI in AMI was formed to develop a set of recommendations to complement and assist clinical judgment. This paper represents the product of their recommendations.
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| 27. |
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| 28. |
- Nordström, Birgitta, et al.
(författare)
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The Geneva-Copenhagen Survey of the Solar Neighbourhood
- 2004
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Ingår i: Publications Astronomical Society of Australia. - 1448-6083. ; 21:2, s. 129-133
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Tidskriftsartikel (refereegranskat)abstract
- We report on a new survey of metallicities, ages, and Galactic orbitsfor a complete, magnitude-limited, and kinematically unbiased all-skysample of 16682 nearby F- and G-dwarfs. Our~63000 new, accurate radialvelocities for nearly 13500 of the stars, combined with Hipparcosparallaxes and Tycho-2 proper motions, complete the kinematic data for14139 stars and allow us to identify most of the binary stars in thesample. Isochrone ages have been determined whenever reliable resultsare possible, with particular attention to realistic error estimates.Among the basic properties of the Galactic disk that can bereinvestigated from our data are the metallicity distribution ofG-dwarfs and the age-metallicity and age-velocity relations of the solarneighbourhood. We confirm the lack of metal-poor G-dwarfs relative toclassical model predictions (the `G-dwarf problem'), the near-constancyof the mean metallicity since the formation of the thin disk, and theappearance of the kinematic signature of the thick disk ~ 10Gyr ago.
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| 29. |
- Nordström, Birgitta, et al.
(författare)
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The Geneva-Copenhagen survey of the Solar neighbourhood. Ages, metallicities, and kinematic properties of ∼14 000 F and G dwarfs
- 2004
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Ingår i: Astronomy & Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 418:3, s. 989-1019
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Forskningsöversikt (refereegranskat)abstract
- We present and discuss new determinations of metallicity, rotation, age,kinematics, and Galactic orbits for a complete, magnitude-limited, andkinematically unbiased sample of 16 682 nearby F and G dwarf stars. Our∼63 000 new, accurate radial-velocity observations for nearly 13 500stars allow identification of most of the binary stars in the sampleand, together with published uvbyβ photometry, Hipparcosparallaxes, Tycho-2 proper motions, and a few earlier radial velocities,complete the kinematic information for 14 139 stars. These high-qualityvelocity data are supplemented by effective temperatures andmetallicities newly derived from recent and/or revised calibrations. Theremaining stars either lack Hipparcos data or have fast rotation. Amajor effort has been devoted to the determination of new isochrone agesfor all stars for which this is possible. Particular attention has beengiven to a realistic treatment of statistical biases and errorestimates, as standard techniques tend to underestimate these effectsand introduce spurious features in the age distributions. Our ages agreewell with those by Edvardsson et al. (cite{edv93}), despite severalastrophysical and computational improvements since then. We demonstrate,however, how strong observational and theoretical biases cause thedistribution of the observed ages to be very different from that of thetrue age distribution of the sample. Among the many basic relations ofthe Galactic disk that can be reinvestigated from the data presentedhere, we revisit the metallicity distribution of the G dwarfs and theage-metallicity, age-velocity, and metallicity-velocity relations of theSolar neighbourhood. Our first results confirm the lack of metal-poor Gdwarfs relative to closed-box model predictions (the ``G dwarfproblem''), the existence of radial metallicity gradients in the disk,the small change in mean metallicity of the thin disk since itsformation and the substantial scatter in metallicity at all ages, andthe continuing kinematic heating of the thin disk with an efficiencyconsistent with that expected for a combination of spiral arms and giantmolecular clouds. Distinct features in the distribution of the Vcomponent of the space motion are extended in age and metallicity,corresponding to the effects of stochastic spiral waves rather thanclassical moving groups, and may complicate the identification ofthick-disk stars from kinematic criteria. More advanced analyses of thisrich material will require careful simulations of the selection criteriafor the sample and the distribution of observational errors.Based on observations made with the Danish 1.5-m telescope at ESO, LaSilla, Chile, and with the Swiss 1-m telescope at Observatoire deHaute-Provence, France.Complete Tables 1 and 2 are only available in electronic form at the CDSvia anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/418/989
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| 30. |
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| 31. |
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| 32. |
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| 33. |
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| 34. |
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| 35. |
- Andersen A.C., Sotelo J.A., Pustovit V.N., Niklasson G.A.
(författare)
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Interstellar extinction by fractal polycrystalline graphite clusters?
- 2002
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Ingår i: Electromagnetic and Light Scattering by Non-spherical Particles. - : Army Research Laboratory. ; , s. 1-4
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Konferensbidrag (refereegranskat)abstract
- Certain dust particles in space are expected to appear as clusters of individual grains. The morphology of these clusters could be fractal or compact. To determine how these structural features would affect the interpretation of the observed interstellar
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| 36. |
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| 37. |
- Andersen, J. N., et al.
(författare)
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Strong phonon replicas in Be 1s photoemission spectra
- 2001
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 86:19, s. 4398-4401
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Tidskriftsartikel (refereegranskat)abstract
- Strong phonon replicas in Be 1s photoemission spectra were investigated. The fine structure caused by intrinsic excitation of a narrow band of optical phonons was discussed in the 1s photoemission proces. The excitations of the optical Be phonons in the photoemission process caused fine structures. It was found that the phonon replicas in Be metal were strong due to large size misfit between neutral and core-ionized Be.
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| 38. |
- Andersen, MK, et al.
(författare)
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Balanced chromosome abnormalities inv(16) and t(15;17) in therapy-related myelodysplastic syndromes and acute leukemia: Report from an international workshop
- 2002
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Ingår i: Genes, Chromosomes and Cancer. - : Wiley. - 1045-2257 .- 1098-2264. ; 33:4, s. 395-400
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Tidskriftsartikel (refereegranskat)abstract
- The Workshop identified 48 unselected patients with therapy-related myelodysplastic syndrome or acute myeloid leukemia (t-MIDS/t-AML) and inv(16), and 41 patients with t(15; 17) after chemotherapy (CT) and/or radiotherapy (RT) for a malignant or nonmalignant disease. The primary diseases were: breast cancer, 33 patients; lymphomas, 24 patients; various other solid tumors, 30 patients; and nonmalignant diseases, 2 patients. The general type of previous therapy was RT only in 10 patients with an inv(16) and in 12 patients with a t(15; 17), alkylating agents plus topoisomerase 11 inhibitors in 24 patients with an inv (16) and in 18 patients with a t(15; 17), topoisomerase 11 inhibitors only in 5 patients with an inv(16) and in 2 patients with a t(15; 17), alkylating agents only in 6 patients in each subgroup, and other types of chemotherapy in 3 patients in each subgroup. Most CT-treated patients (69%) also received RT. The latency period to development of t-MDS/t-AML was short: a median of 22 months in patients with inv(16) and 29 months in patients with t(15; 17). Twenty-six patients (54%) with an inv(16) and 17 patients (41%) with a t(15; 17) had additional cytogenetic abnormalities, which were unrelated to age and survival in both subgroups. Trisomy of chromosomes 8, 21, and 22 and del(7q) were the most frequent additional abnormalities in the inv(16) subgroup, whereas +8, -5, and del(16q) were most frequent in the t(15; 17) subgroup. The disease was overt t-AML in 38/48 patients (79%) with an inv(16) and in 38/41 patients (93%) with a t(15; 17). Thirty-three of 39 intensively treated patients (85%) with an inv(16) obtained a complete remission, whereas 24 of 35 intensively treated patients (69%) with a t(15; 17) obtained a complete remission. The median overall survival of intensively treated patients was 29 months in both cytogenetic subgroups. In the inv(16) subgroup, patients younger than 55 years of age had a longer survival when compared with older patients (P = 0.006). The study supports the observation that t-MDS/t-AML with inv(16) and t(15; 17) is often associated with prior therapy with topoisomerase 11 inhibitors; however, a notable finding was the high frequency of treatment with only radiotherapy, 29% of t(15; 17) and 21 % of inv(16). Response rates to intensive chemotherapy in this study were comparable to those of de novo disease.
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| 39. |
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| 40. |
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| 41. |
- Andersen, Oluf, 1941, et al.
(författare)
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Multicentre, randomised, double blind, placebo controlled, phase III study of weekly, low dose, subcutaneous interferon beta-1a in secondary progressive multiple sclerosis
- 2004
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Ingår i: JOURNAL OF NEUROLOGY NEUROSURGERY AND PSYCHIATRY. - : BMJ. - 0022-3050 .- 1468-330X. ; 75:5, s. 706-710
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Tidskriftsartikel (refereegranskat)
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| 42. |
- Andersen, Torben, et al.
(författare)
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The Euro50 Extremely Large Telescope
- 2003
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Ingår i: Future Giant Telescopes. Proceedings of the SPIE.. - 081944619X ; 4840, s. 214-225
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Konferensbidrag (refereegranskat)abstract
- Euro50 is a proposed optical telescope with an equivalent primary mirrordiameter of 50 m. Partners of the collaboration are institutes inSweden, Spain, Ireland, Finland, and the UK. The telescope will have asegmented primary mirror and an aplanatic Gregorian configuration withtwo elliptical mirrors. For a 50 m telescope there would be noeconomical advantage in going to a spherical primary. The size of theprimary mirror segments (2 m) has been selected on the basis of aminimization of cost. An adaptive optics system will be integrated intothe telescope. The telescope will have three operational modes: Seeinglimited observations, single conjugate adaptive observations in theK-band, and dual conjugate observations also in the K-band. An upgradeto adaptive optics also in the visible down to 500 nm is foreseen. Therewill be an enclosure to protect the telescope against adverse weatherand wind disturbances. Integrated simulation models are underdevelopment. The project time will be 10 years and the cost some 591MEuros.
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| 43. |
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| 44. |
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| 45. |
- Browne, Michael, et al.
(författare)
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Parallelization of MATLAB for Euro50 integrated modeling
- 2004
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Ingår i: Modeling and Systems Engineering for Astronomy (Proceedings of the SPIE). - : SPIE. - 081945429X ; 5497, s. 604-610
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Konferensbidrag (refereegranskat)abstract
- MATLAB and its companion product Simulink are commonly used tools insystems modelling and other scientific disciplines. A cross-disciplinaryintegrated MATLAB model is used to study the overall performance of theproposed 50m optical and infrared telescope, Euro50. However thecomputational requirements of this kind of end-to-end simulation of thetelescope's behaviour, exceeds the capability of an individualcontemporary Personal Computer. By parallelizing the model, primarily ona functional basis, it can be implemented across a Beowulf cluster ofgeneric PCs. This requires MATLAB to distribute in some way data andcalculations to the cluster nodes and combine completed results. Therehave been a number of attempts to produce toolkits to allow MATLAB to beused in a parallel fashion. They have used a variety of techniques. Herewe present findings from using some of these toolkits and proposedadvances.
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| 46. |
- Bruder, CEG, et al.
(författare)
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High resolution deletion analysis of constitutional DNA from neurofibromatosis type 2 (NF2) patients using microarray-CGH
- 2001
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Ingår i: Human Molecular Genetics. - Oxford, United Kingdom : Oxford University Press. - 0964-6906 .- 1460-2083. ; 1, s. 271-
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Tidskriftsartikel (refereegranskat)abstract
- Neurofibromatosis type 2 (NF2) is an autosomal dominant disorder whose hallmark is bilateral vestibular schwannoma. It displays a pronounced clinical heterogeneity with mild to severe forms. The NF2 tumor suppressor (merlin/schwannomin) has been cloned and extensively analyzed for mutations in patients with different clinical variants of the disease. Correlation between the type of the NF2 gene mutation and the patient phenotype has been suggested to exist. However, several independent studies have shown that a fraction of NF2 patients with various phenotypes have constitutional deletions that partly or entirely remove one copy of the NF2 gene. The purpose of this study was to examine a 7 Mb interval in the vicinity of the NF2 gene in a large series of NF2 patients in order to determine the frequency and extent of deletions. A total of 116 NF2 patients were analyzed using high-resolution array-comparative genomic hybridization (CGH) on an array covering at least 90% of this region of 22q around the NF2 locus. Deletions, which remove one copy of the entire gene or are predicted to truncate the schwannomin protein, were detected in 8 severe, 10 moderate and 6 mild patients. This result does not support the correlation between the type of mutation affecting the NF2 gene and the disease phenotype. This work also demonstrates the general usefulness of the array-CON methodology for rapid and comprehensive detection of small (down to 40 kb) heterozygous and/or homozygous deletions occurring in constitutional or tumor-derived DNA.
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| 47. |
- Cayrel, R., et al.
(författare)
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Determination of [O/Fe] in BD +23 3130 from ESO VLT-UVES observations
- 2001
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Ingår i: New Astronomy Reviews. - 1872-9630. ; 45:8, s. 533-535
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Tidskriftsartikel (refereegranskat)abstract
- We report a new determination of [O/Fe, the relative logarithmicabundance of O/Fe with respect to the Sun, for the very metal-poor starBD+23 3130 ([Fe/H=-2.6). The value was derived from the forbidden line[O I at 630 nm and from six weak Fe II lines, with a S/N ratiosubstantially larger than those obtained before, thanks to theefficiency of the VLT-UVES instrument at Paranal. We obtain[O/Fe=0.71+/-0.25, a value 0.36 dex higher than the value obtained fromthe same lines by Fulbright and Kraft [AJ 118 (1999) 527, but 0.46lower than the one derived by Israelian et al. [ApJ 507 (1998) 805 fromthe UV OH bands.
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| 48. |
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| 49. |
- Cayrel, R., et al.
(författare)
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First stars V - Abundance patterns from C to Zn and supernova yields in the early Galaxy
- 2004
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Ingår i: Astronomy & Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 416:3, s. 1117-1138
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Tidskriftsartikel (refereegranskat)abstract
- In the framework of the ESO Large Programme ``First Stars'', veryhigh-quality spectra of some 70 very metal-poor dwarfs and giants wereobtained with the ESO VLT and UVES spectrograph. These stars are likelyto have descended from the first generation(s) of stars formed after theBig Bang, and their detailed composition provides constraints on issuessuch as the nature of the first supernovae, the efficiency of mixingprocesses in the early Galaxy, the formation and evolution of the haloof the Galaxy, and the possible sources of reionization of the Universe.This paper presents the abundance analysis of an homogeneous sample of35 giants selected from the HK survey of Beers et al. (cite{BPS92},cite{Be99}), emphasizing stars of extremely low metallicity: 30 of our35 stars are in the range -4.1 <[Fe/H]< -2.7, and 22 stars have[Fe/H] < -3.0. Our new VLT/UVES spectra, at a resolving power ofR∼45 000 and with signal-to-noise ratios of 100-200 per pixel overthe wavelength range 330-1000 nm, are greatly superior to those of theclassic studies of McWilliam et al. (cite{MPS95}) and Ryan et al.(cite{RNB96}).The immediate objective of the work is to determine precise,comprehensive, and homogeneous element abundances for this large sampleof the most metal-poor giants presently known. In the analysis wecombine the spectral line modeling code ``Turbospectrum'' with OSMARCSmodel atmospheres, which treat continuum scattering correctly and thusallow proper interpretation of the blue regions of the spectra, wherescattering becomes important relative to continuous absorption (λ< 400 nm). We obtain detailed information on the trends of elementalabundance ratios and the star-to-star scatter around those trends,enabling us to separate the relative contributions of cosmic scatter andobservational/analysis errors.Abundances of 17 elements from C to Zn have been measured in all stars,including K and Zn, which have not previously been detected in starswith [Fe/H] < -3.0. Among the key results, we discuss the oxygenabundance (from the forbidden [OI] line), the different and sometimescomplex trends of the abundance ratios with metallicity, the very tightrelationship between the abundances of certain elements (e.g., Fe andCr), and the high [Zn/Fe] ratio in the most metal-poor stars. Within theerror bars, the trends of the abundance ratios with metallicity areconsistent with those found in earlier literature, but in many cases thescatter around the average trends is much smaller than found in earlierstudies, which were limited to lower-quality spectra. We find that thecosmic scatter in several element ratios may be as low as 0.05 dex.The evolution of the abundance trends and scatter with decliningmetallicity provides strong constraints on the yields of the firstsupernovae and their mixing into the early ISM. The abundance ratiosfound in our sample do not match the predicted yields frompair-instability hypernovae, but are consistent with element productionby supernovae with progenitor masses up to 100 M⊙.Moreover, the composition of the ejecta that have enriched the matterBased on observations obtained in the frame of the ESO programme ID165.N-0276(A).Full Tables 3 and 8 are available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/416/1117 This work hasmade use of the SIMBAD database.
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| 50. |
- Cayrel, R., et al.
(författare)
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Measurement of stellar age from uranium decay
- 2001
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 409:6821, s. 691-692
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Tidskriftsartikel (refereegranskat)abstract
- The ages of the oldest stars in the Galaxy indicate when star formationbegan, and provide a minimum age for the Universe. Radioactive dating ofmeteoritic material and stars relies on comparing the present abundanceratios of radioactive and stable nuclear species to the theoreticallypredicted ratios of their production. The radioisotope 232Th(half-life 14Gyr) has been used to date Galactic stars, but it decays byonly a factor of two over the lifetime of the Universe. 238U(half-life 4.5Gyr) is in principle a more precise age indicator, buteven its strongest spectral line, from singly ionized uranium at awavelength of 385.957nm, has previously not been detected in stars. Herewe report a measurement of this line in the very metal-poor starCS31082-0018, a star which is strongly overabundant in itsheavy elements. The derived uranium abundance, log(U/H) = -13.7 +/- 0.14+/- 0.12 yields an age of 12.5 +/- 3Gyr, though this is still modeldependent. The observation of this cosmochronometer gives the mostdirect age determination of the Galaxy. Also, with improved theoreticaland laboratory data, it will provide a highly precise lower limit to theage of the Universe.
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