| 1. |
- Andre, M., et al.
(author)
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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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In: Annales Geophysicae. - : Copernicus GmbH. - 0992-7689 .- 1432-0576. ; 19:12-okt, s. 1471-1481
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Journal article (peer-reviewed)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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| 2. |
- Aurora, P., et al.
(author)
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Multiple breath inert gas washout as a measure of ventilation distribution in children with cystic fibrosis
- 2004
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In: Thorax. - : BMJ. - 0040-6376. ; 59:12, s. 1068-73
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Journal article (peer-reviewed)abstract
- BACKGROUND: Multiple breath inert gas washout (MBW) has been suggested as a tool for detecting early cystic fibrosis (CF) lung disease. A study was undertaken to compare the relative sensitivity of MBW and spirometry for detecting abnormal lung function in school age children with CF and to compare MBW results obtained from healthy children in the UK with those recently reported from Sweden. METHODS: Forced expiratory volume in 1 second (FEV1) and maximal expiratory flow when 25% of forced vital capacity remains to be expired (MEF25) were compared with the lung clearance index (LCI) derived from sulphur hexafluoride MBW in 22 children with CF aged 6-16 years and in 33 healthy controls. RESULTS: LCI was higher in children with CF than in healthy controls (mean difference 5.1 (95% CI of difference 4.1 to 6.1) and FEV1 and MEF25 z-scores were lower (mean difference -2.3 (95% CI -2.9 to -1.7) and -1.8 (95% CI -2.4 to -1.3), respectively; p<0.001 for all). There was a significant negative correlation between LCI and FEV1 (r2 = 0.62) and MEF25 (r2 = 0.46). However, while normal (> or =-1.96 z-scores) FEV1 and MEF25 results were seen in 11 (50%) and 12 (53%) children with CF, respectively, all but one of these children had an abnormally increased LCI. LCI was repeatable in both groups (within subject CV for three measurements 6% for CF and 5% for healthy children). In healthy subjects LCI was independent of age and virtually identical in the British and Swedish children (mean difference 0.1 (95% CI -0.1 to 0.4), p = 0.38) CONCLUSIONS: MBW is reproducible between laboratories, generates normal ranges which are constant over childhood, and is more frequently abnormal than spirometry in children with CF.
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| 3. |
- Gustafsson, David, et al.
(author)
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Modeling water and heat balance of the boreal landscape - comparison of forest and arable land in Scandinavia
- 2004
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In: Journal of applied meteorology (1988). - 0894-8763 .- 1520-0450. ; 43:11, s. 1750-1767
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Journal article (peer-reviewed)abstract
- The water and heat balances of an arable field and a forest in the boreal zone in Scandinavia were explored using 3 yr of observations and simulations with two different soil - vegetation - atmosphere transfer (SVAT) models over a 30-yr period. Results from a detailed mechanistic model [ coupled heat and mass transfer model ( COUP)] were compared with those obtained with a large-scale type of SVAT model used in the weather prediction model at the European Centre for Medium-Range Weather Forecasts [ECMWF tiled land surface scheme (TESSEL)]. The COUP model simulations agreed well with the observations from a seasonal perspective. The TESSEL model differed significantly from the measurements when standard operational parameter values were used. The introduction of a seasonal variation in leaf-area index values, tuned canopy resistance for forest, and a reduced roughness length over snow-covered open land reduced the discrepancies. Net radiation was 40% higher in the forest when compared with the arable land, based on 30-yr simulations with both models. Furthermore, the forest was a net source of sensible heat flux, whereas the arable land was a net sink. Because of different treatment of winter interception evaporation, forest latent heat flux based on the COUP model considerably exceeded that from the TESSEL model, and suggested that the total annual evaporation was higher from the forest than from arable land. The representation of interception evaporation in winter, as well as seasonal dynamics in vegetation properties are, thus, of considerable importance for adequate simulation of forest and arable land energy fluxes within the boreal zone.
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| 4. |
- Gustafsson, Georg, et al.
(author)
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First results of electric field and density observations by Cluster EFW based on initial months of operation
- 2001
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In: Annales Geophysicae. - : Copernicus GmbH. - 0992-7689 .- 1432-0576. ; 19:12-okt, s. 1219-1240
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Journal article (peer-reviewed)abstract
- Highlights are presented from studies of the electric field data from various regions along the CLUSTER orbit. They all point towards a very high coherence for phenomena recorded on four spacecraft that are separated by a few hundred kilometers for structures over the whole range of apparent frequencies from I mHz to 9 kHz. This presents completely new opportunities to study spatial-temporal plasma phenomena from the magnetosphere out to the solar wind. A new probe environment was constructed for the CLUSTER electric field experiment that now produces data of unprecedented quality. Determination of plasma flow in the solar wind is an example of the capability of the instrument.
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| 5. |
- Gustafsson, Helen, et al.
(author)
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MAGIC-type polymer gel for three-dimensional dosimetry: intensity-modulated radiation therapy verification.
- 2003
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In: Medical Physics. - : Wiley. - 0094-2405. ; 30:6, s. 1264-1271
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Journal article (peer-reviewed)abstract
- A new type of polymer gel dosimeter, which responds well to absorbed dose even when manufactured in the presence of normal levels of oxygen, was recently described by Fong et al. [Phys. Med. Biol. 46, 3105-3113 (2001)] and referred to by the acronym MAGIC. The aim of this study was to investigate the feasibility of using this new type of gel for intensity-modulated radiation therapy (IMRT) verification. Gel manufacturing was carried out in room atmosphere under normal levels of oxygen. IMRT inverse treatment planning was performed using the Helios software. The gel was irradiated using a linear accelerator equipped with a dynamic multileaf collimator, and intensity modulation was achieved using sliding window technique. The response to absorbed dose was evaluated using magnetic resonance imaging. Measured and calculated dose distributions were compared with regard to in-plane isodoses and dose volume histograms. In addition, the spatial and dosimetric accuracy was evaluated using the gamma formalism. Good agreement between calculated and measured data was obtained. In the isocenter plane, the 70% and 90% isodoses acquired using the different methods are mostly within 2 mm, with up to 3 mm disagreement at isolated points. For the planning target volume (PTV), the calculated mean relative dose was 96.8 +/- 2.5% (1 SD) and the measured relative mean dose was 98.6 +/- 2.2%. Corresponding data for an organ at risk was 34.4 +/- 0.9% and 32.7 +/- 0.7%, respectively. The gamma criterion (3 mm spatial/3% dose deviation) was fulfilled for 94% of the pixels in the target region. Discrepancies were found in hot spots the upper and lower parts of the PTV, where the measured dose was up to 11% higher than calculated. This was attributed to sub optimal scatter kernels used in the treatment planning system dose calculations. Our results indicate great potential for IMRT verification using MAGIC-type polymer gel.
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| 6. |
- Macrae, Duncan J, et al.
(author)
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Inhaled nitric oxide therapy in neonates and children: reaching a European consensus.
- 2004
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In: Intensive care medicine. - : Springer Science and Business Media LLC. - 0342-4642 .- 1432-1238. ; 30:3, s. 372-80
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Journal article (peer-reviewed)abstract
- Inhaled nitric oxide (iNO) was first used in neonatal practice in 1992 and has subsequently been used extensively in the management of neonates and children with cardiorespiratory failure. This paper assesses evidence for the use of iNO in this population as presented to a consensus meeting jointly organised by the European Society of Paediatric and Neonatal Intensive Care, the European Society of Paediatric Research and the European Society of Neonatology. Consensus Guidelines on the Use of iNO in Neonates and Children were produced following discussion of the evidence at the consensus meeting.
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