| 1. |
- Collin, Sven-Olof, et al.
(författare)
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Market Segmentation in Scientific Publications : Research Patterns in American vs European Management Journals
- 1996
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Ingår i: British Journal of Management. - Chichester : Wiley-Blackwell. - 1045-3172 .- 1467-8551. ; 7:2, s. 141-154
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Tidskriftsartikel (refereegranskat)abstract
- Ideal science should conform to certain criteria or goals, among them the goals of universalism and commonality. Realization of these goals may be limited, however, through the dividing up of researchers in terms of geographical borders. In this study the general hypothesis is tested that there is a segmentation of the society of management researchers into a North American (US) and a European (E) segment, a segmentation which is furthered by differences in incentive schemes and in paradigms. Four leading management journals from North America and from Europe, respectively, and the 242 articles they contained published in 1993 were selected to represent the different geographical segments. The results provide: support for the existence of two such segments; support for differences in incentive schemes influencing the articles; support for their being paradigm differences between the two segments; and support for a paradigm effect being stronger in US-journals than in E-journals, US-authors are more willing, however, to conform to the E-paradigm than vice versa. We argue for methodological pragmatism in order to reduce the presumed counter-productive effects of paradigmatic rigidity.
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| 2. |
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| 3. |
- Janson, Per-Olof, 1940, et al.
(författare)
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Acromegaly and Cushing's syndrome due to ectopic production of GHRH and ACTH by a thymic carcinoid tumour: in vitro responses to GHRH and GHRP-6.
- 1998
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Ingår i: Clinical endocrinology. - 0300-0664. ; 48:2, s. 243-50
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Tidskriftsartikel (refereegranskat)abstract
- A 50-year-old male presented with diabetes mellitus and Cushing's syndrome associated with a large mediastinal mass. The levels of serum cortisol were high (1500-1800 nmol/l) without diurnal variation. Plasma ACTH levels (200-250 ng/l) and urinary excretion of cortisol were also increased. The levels of these hormones did not change in response to stimulation with corticotrophin releasing hormone (CRH) or suppression with high doses of dexamethasone. The patient had an elevated baseline GH level (7.3 mU/l), and the levels of immunoreactive GH-releasing hormone (GHRH) in eight plasma samples were markedly increased (600-1500 ng/l). Circulating levels of IGF-1, chromogranin A and neuropeptide Y (NPY) were also increased. Computer-assisted tomography and octreotide scintigraphy revealed a large mediastinal tumour and metastases in the left supraclavicular fossa. During treatment with octreotide, the baseline GH level was decreased (to 4.4 mU/l), while the GH pulse height was unchanged. Surgical removal of most of the tumour tissue resulted in a further decrease in the baseline serum GH level to a value (1.6 mU/l) about 20% of that before treatment, while the pulse height and mean GH were affected to a lesser extent. Postoperatively, circulating levels of cortisol and IGF-1 decreased, and the patient exhibited clinical improvement. Histological examination showed a neuroendocrine tumour with characteristics consistent with a foregut carcinoid of thymic origin. Immunoreactive GHRH, ACTH and NPY, but not immunoreactive GH, were detected in 80-90% of the tumour cells and the three peptides appeared to be co-localized. In primary culture, cells from this tumour displayed calcium influx in response to GHRH or GH releasing peptide-6 (GHRP-6), while there were not such responses by cells from another carcinoid not producing GHRH, ACTH or NPY. These results demonstrate a rare case of ectopic production of GHRH, ACTH and NPY, and indicate that the tumour cells were responsive to GHRH and GHRP-6 as well as octreotide.
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| 4. |
- Larsson, Gunilla, et al.
(författare)
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Crystal structure of the Escherichia coli dUTPase in complex with a substrate analogue (dUDP)
- 1996
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Ingår i: Nature Structural & Molecular Biology. - : Springer Science and Business Media LLC. - 1545-9985 .- 1545-9993. ; 3:6, s. 532-538
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Tidskriftsartikel (refereegranskat)abstract
- We have determined the structure of the homotrimeric dUTPase from Escherichia coli, complexed with an inhibitor and substrate analogue, dUDP. Three molecules of dUDP are found symmetrically bound per trimer, each in a shallow cleft between adjacent subunits, interacting with evolutionary conserved residues. The interactions of the uracil ring and the deoxypentose with the protein are consistent with the high specificity of the enzyme with respect to these groups. The positions of the two phosphate groups and adjacent water molecules are discussed in relation to the mechanism and kinetics of catalysis. The role that dUTPase plays in DNA metabolism makes the enzyme a potential target for chemotherapeutic drugs: the results presented here will aid in the design and development of inhibitory compounds.
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| 5. |
- Larsson, G, et al.
(författare)
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Crystallization and preliminary X-ray analysis of human dUTPase
- 1996
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Ingår i: Acta Crystallographica. Section D: Biological Crystallography. - 1399-0047. ; D52:5, s. 1039-1040
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Tidskriftsartikel (refereegranskat)abstract
- Human dUTPase, expressed in Escherichia coli, has been crystallized. Single crystals were obtained by the vapour-diffusion technique using 2-propanol and PEG 4000 as precipitants. The enzyme was co-crystallized with the substrate dUTP and a metal chelator EDTA to prevent hydrolysis of the substrate. The crystals belong to the orthorombic space group P212121 with cell dimensions a = 67.51, b = 68.26 and c = 91.00 Å. The crystallographic asymmetric unit contains one trimer of identical subunits.
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| 6. |
- Larsson, Per-Olof, et al.
(författare)
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Combustion of CO and toluene; Characterisation of copper oxide supported on titania and activity comparisons with supported cobalt, iron, and manganese oxide
- 1996
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Ingår i: Journal of Catalysis. - : Elsevier BV. - 1090-2694 .- 0021-9517. ; 163:2, s. 279-293
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Tidskriftsartikel (refereegranskat)abstract
- Titania-supported copper oxide catalysts have been prepared with loadings in the range from 1/3 to 5 theoretical layers and have been tested for the combustion of CO and toluene. Characterisation with XRD, electron microscopy, EDX, TPR, Raman, and XPS gives details about the structure of copper oxide on titania. The results show that dispersed CuOx is formed up to a loading of about one theoretical layer. TPR indicates the formation of two types of dispersed species, which possibly are isolated and polymeric, respectively. XPS data show that the dispersed copper is Cu2+. Th, dispersed species have high catalytic activity for combustion. At higher copper oxide loading, bulk CuO is formed, contributing little to the activity. Comparison of three titania supports with differing surface area and pore size distribution shows that the most favorable is a support with a surface area of about 38 m(2)/g and mesopores in the range 100-800 Angstrom. The longevity of the catalysts was tested in the waste gas from a formaldehyde plant. Deactivation was observed after being on stream for 57 days, and the deactivation is due to sintering of both the support and the copper oxide. Copper oxide on titania is shown to be more active than cobalt, manganese, and iron oxide on the same support. (C) 1996 Academic Press, Inc.
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| 7. |
- Svensson, Olof
(författare)
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Extensions of Fatou theorems in products of upper half-spaces
- 1995
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Ingår i: Mathematica Scandinavica. - Aarhus, Denmark : Aarhus Universitet, Mathematica Scandinavica. - 0025-5521 .- 1903-1807. ; 76:1, s. 139-151
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Tidskriftsartikel (refereegranskat)abstract
- We consider a multi-parameter maximal function and give a necessary and sufficient condition for its boundedness on Lp, P > 1. We also prove that the maximal function with suitable restriction parameters is of weak type (1,1).
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| 8. |
- Svensson, Olof
(författare)
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Nonadmissible convergence in symmetric spaces
- 1996
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Ingår i: Journal für die Reine und Angewandte Mathematik. - : Walter de Gruyter GmbH. - 0075-4102 .- 1435-5345. ; :472, s. 53-68
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Tidskriftsartikel (refereegranskat)abstract
- In the disc (or half-plane, or half-space) the well-known Fatou theorem says that the Poisson integral of an $L^1$-function has non-tangential boundary limits a.e. J. Marcinkiewicz and A. Zygmund cleared up the corresponding situation in products of discs (or half-spaces), introducing the notions of restricted and unrestricted non-tangential convergence. For general Riemannian symmetric spaces the corresponding notions ("restricted and unrestricted admissible convergence") have also been found, and the classical results generalized, some time ago. In 1984 A. Nagel and E. M. Stein investigated again the half-space case and found that the convergence theorem could be proved for slightly larger than nontangential approach domains (the exact description is too technical to state here). The subject of the present paper is to extend this investigation to general Riemannian symmetric spaces. The notion of restricted admissible convergence (which is the natural one for $L^1$-functions) is appropriately extended and the convergence theorem proved in a way which seems to be the final word on the subject. Unrestricted convergence (which goes with $L^p$ functions, $p>1$) is also discussed and a theorem proved, but only in the case of one particular example of a space of rank two. The proofs display considerable virtuosity in the application of real-variable methods.
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| 9. |
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| 10. |
- Svensson, Olof, 1965
(författare)
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Time-Resolved and High-Energy Synchrotron Radiation Crystallography using X-ray Area Detectors: Calibration and Applications
- 1996
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis relates to characterisation and calibration techniques for X-ray area detectors with applications in time-resolved and high-energy X-ray crystallography. X-ray crystallography is an interdisciplinary science with important applications in many fields, e.g. chemistry, physics, biology, geology and materials science. With the advent of third generation synchrotron radiation (SR) sources, which offer X-ray beams of high flux, brilliance and energy, new areas of time-resolved crystallography (e.g. in-situ studies of phase transitions, chemical reactions and excited states) and high-energy crystallography (e.g. accurate structural studies) have become accessible. X-ray area detectors can simultaneously record a large solid angle of scattered X-ray photons. This is an important advantage, compared to point or one-dimensional detectors. However, X-ray area detectors are complicated, and can, due to various reasons (e.g. detector geometry), introduce distortions (i.e. systematic errors) into the acquired data. Given that these distortions are reproducible, they can be characterised and very largely corrected. In this thesis are developed techniques for characterisation and calibration of spatial distortion, non-uniformity of response and intensity non-linearity of X-ray area detectors, which were successfully used in a number of time-resolved and high-energy studies: Time-resolved in-situ study of the solid-state polymerisation of S2N2 to (SN)x using high-energy monochromatic X-ray powder diffraction. Apart from reaction kinetics, the experiment also yielded information relating to the polymerisation mechanism on both the macroscopic (bulk) and microscopic (atomic) level. Time-resolved study of the conversion of .alfa.-(ET)2I31 to .alfa.T-(ET)2I3 using high-energy monochromatic single-crystal diffraction: A metal-superconductor transition. The conversion was found to be of non-diffusive nature, and the structure of .alfa.T-(ET)2I3 was elucidated for the first time. Time-resolved single-crystal diffraction study of a phase transition in Ni3Sb. The transition was followed by recording the time evolution of individual peaks, and was found to be a diffusionless displacive transition. This thesis demonstrates the usefulness of the combination of X-ray area detectors and high-energy synchrotron radiation in general, and in particular the high data quality obtained after applying calibration techniques. 1 (where ET is bis(ethylenedithio)tetrathiafulvalene, C10S8H8)
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