| 31. |
- Ivchenko, Nickolay V., et al.
(författare)
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Multispectral observations of auroral rays and curls
- 2005
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Ingår i: Geophysical Research Letters. - : American Geophysical Union (AGU). - 0094-8276 .- 1944-8007. ; 32:18
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Tidskriftsartikel (refereegranskat)abstract
- Two cases of discrete aurora are presented, in which auroral curls and auroral rays, respectively, were seen. The aurora was imaged by two spatially separated imagers with a long-pass filter ( mainly sensitive to N-2 and N-2(+) emissions), and another imager with a narrow- band 7325 angstrom filter ( sensitive to forbidden O+ doublet). Also, spectra of the aurora were recorded. Using the multispectral imaging and spectra we find that the curls occurred in aurora caused by precipitation of energetic electrons with a lack of low-energy population, while in the rays both high and low energy precipitation were present simultaneously. These findings are confirmed by the altitude determination from triangulation.
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| 32. |
- Lehmann, O. J., et al.
(författare)
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Novel anterior segment phenotypes resulting from forkhead gene alterations: Evidence for cross-species conservation of function
- 2003
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Ingår i: Investigative Ophthalmology & Visual Science. - : Association for Research in Vision and Ophthalmology (ARVO). - 0146-0404 .- 1552-5783. ; 44:6, s. 2627-2633
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE. Mutations in murine and human Versions of an ancestrally related gene usually result in similar phenotypes. However, interspecics differences exist, and in the case of two forkhead transcription factor genes (FOXC1 and FOXC2), these differences include corneal or anterior segment phenotypes, respectively. This study was undertaken to determine whether such discrepancies provide an opportunity for identifying novel human-murine ocular phenotypes. METHODS. Four pedigrees with early-onset glaucoma phenotypes secondary to segmental chromosomal duplications or deletions encompassing FOXC1 and 18 individuals from 9 FOXC2 mutation pedigrees underwent detailed ocular phenotyping. Subsequently, mice with mutations in Foxc1 or a related forkhead gene, Foxe3, were assessed for features of the human phenotypes. RESULTS. A significant increase in central corneal thickness was present in affected individuals from the segmental duplication pedigrees compared with their unaffected relatives (mean increase 13%, maximum 35%, P < 0.05). Alterations in corneal thickness were present in mice heterozygous and homozygous for Foxe3 mutations but neither in Foxc1 heterozygotes nor the small human segmental deletion pedigree. Mutations in FOXC2 resulted in ocular anterior segment anomalies. These were more severe and prevalent with mutations involving the forkhead domain. CONCLUSIONS. Normal corneal development is dependent on the precise dose and levels of activity of certain forkhead transcription factors. The altered corneal thickness attributable to increased forkhead gene dosage is particularly important, because it may affect the clinical management of certain glaucoma subtypes and lead to excessive treatment. The FOXC1 and Foxe3 data, taken together with the novel ocular phenotypes of FOXC2 mutations, highlight the remarkable cross-species conservation of function among forkhead genes.
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| 33. |
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| 34. |
- Mostajeran, M., et al.
(författare)
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Acute mitogen-activated protein kinase 1/2 inhibition improves functional recovery and vascular changes after ischaemic stroke in rat-monitored by 9.4 T magnetic resonance imaging
- 2018
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Ingår i: Acta Physiologica. - : Wiley. - 1748-1716 .- 1748-1708. ; 223:1
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Tidskriftsartikel (refereegranskat)abstract
- Aim: The aim was to evaluate the beneficial effect of early mitogen-activated protein kinase (MEK)1/2 inhibition administered at a clinical relevant time-point using the transient middle cerebral artery occlusion model and a dedicated rodent magnetic resonance imaging system (9.4T) to monitor cerebrovascular changes non-invasively for 2 weeks. Method: Transient middle cerebral artery occlusion was induced in male rats for two hours followed by reperfusion. The specific MEK1/2 inhibitor U0126 was administered ip at 6 and 24 hours post-reperfusion. Neurological functions were evaluated by 6- and 28-point tests. 9.4 T magnetic resonance imaging was used to monitor morphological infarct changes at day 2, 8 and 14 after stroke and to evaluate cerebral perfusion at day 14. Immunohistochemistry evaluation of Ki67 was performed 14 days post-stroke. Results: U0126 improved long-term behavioural outcome and significantly reduced infarct size. In addition, cerebral perfusion in U0126-treated animals was improved compared to the vehicle group. Immunohistochemistry showed a significant increase in Ki67+ cells in U0126-treated animals compared to the vehicle group. Conclusion: Early MEK1/2 inhibition improves long-term functional outcome, promotes recovery processes after stroke and most importantly provides a realistic time window for therapy.
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| 35. |
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| 36. |
- Schlatter, Nicola, 1985-, et al.
(författare)
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Radar interferometer calibration of the EISCAT Svalbard Radar and a additional receiver station
- 2013
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Ingår i: Journal of Atmospheric and Solar-Terrestrial Physics. - : Elsevier BV. - 1364-6826 .- 1879-1824. ; 105-106, s. 287-292
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Tidskriftsartikel (refereegranskat)abstract
- The EISCAT Svalbard Radar has two parabolic dishes. In order to attempt to implement radar aperture synthesis imaging methods three smaller, passive receive array antennas were built. Several science goals for this new receiver system exist, the primary of which is to study so called naturally enhanced ion acoustic lines. In order to compare radar aperture synthesis imaging results with measurements from optical imagers, calibration of the radar interferometer system is necessary. In this work we present the phase calibration of the EISCAT Svalbard interferometer including one array antenna. The calibration was done using the coherent scatter from satellites passing through the radar beam. Optical signatures of the satellite transits provide accurate position for the satellites. By using transits of a number of satellites sufficient for mapping the radar beam, the interferometric cross-phase was fitted within the radar beam. The calibration technique presented in this work will be applied to all antenna pairs of the antenna configuration for future interferometry studies.
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| 37. |
- Stowell, Sean R, et al.
(författare)
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Galectins-1, -2 and -3 exhibit differential recognition of sialylated glycans and blood group antigens
- 2008
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 283:15, s. 10109-10123
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Tidskriftsartikel (refereegranskat)abstract
- Human galectins have functionally divergent roles, although most of the members of the galectin family bind weakly to the simple disaccharide lactose (Galss1-4Glc). To assess galectin-glycan interactions in more detail, we explored the binding of several important galectins (Gal-1, Gal-2, and Gal-3) on a glycan microarray containing hundreds of structurally diverse glycans. All three galectins exhibited unique glycan binding characteristics. Only Gal-1 and Gal-2 bound complex-type N-glycans and extended core 1 O-glycans with high affinity, while Gal-2 and Gal-3, but not Gal-1, bound A and B blood group antigens. Gal-2 failed to recognize any sialylated glycans regardless of linkage, whereas Gal-1 and Gal-3 bound a2-3, but not a2-6 sialylated glycans. All galectins showed higher binding to sulfated glycans relative to unsulfated ones. Each galectin exhibited higher binding for glycans with poly-N-acetyllactosamine (PL) sequences (Galss1-4GlcNAc)n when compared to N-acetyllactosamine (Galss1-4GlcNAc) in the microarray. However, only Gal-3 preferred PL when assessed by solution-based surface plasmon resonance. Removal of the terminal galactose residue in PL abrogated its recognition by Gal-1 and Gal-2 while having no substantial effect on Gal-3 recognition, demonstrating that Gal-3 recognizes internal N-acetyllactosamine units. These results provide novel insights into the functional constraints of glycan recognition by each galectin and underscore the basis for differences in biological activity.
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| 38. |
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