| 11. |
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| 12. |
- Dencker, Magnus, et al.
(författare)
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Daily physical activity and its relation to aerobic fitness in children aged 8-11 years.
- 2006
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Ingår i: European Journal of Applied Physiology. - : Springer Science and Business Media LLC. - 1439-6327 .- 1439-6319. ; 96:5, s. 587-592
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Tidskriftsartikel (refereegranskat)abstract
- A positive relationship between daily physical activity and aerobic fitness exists in adults. Studies in children have given conflicting results, possibly because of differences in methods used to assess daily physical activity and fitness. No study regarding daily physical activity and fitness in children has been published, where fitness has been assessed by direct measurement of maximum oxygen uptake and related to daily physical activity intensities by accelerometers. We examined 248 children (140 boys and 108 girls), aged 7.9-11.1 years. Maximum workload and maximal oxygen uptake (VO2PEAK) by indirect calorimetry were measured during a maximum bicycle ergometer exercise test. Exercise capacity was adjusted for body mass and (body mass)(2/3). Daily physical activity was evaluated by accelerometers, worn around the waist for 4 days. Mean accelerometer counts and time spent in vigorous physical activity were calculated. VO2PEAK was correlated with mean accelerometer counts (r=0.23 for boys and r=0.23 for girls, both P < 0.05), but somewhat better with time spent in vigorous activity (r=0.32 for boys, r=0.30 for girls, both P < 0.05). All results remained virtually the same regardless of the method used to adjust for differences in body size.
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| 13. |
- Dencker, Magnus, et al.
(författare)
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Gender differences and determinants of aerobic fitness in children aged 8-11 years.
- 2007
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Ingår i: European Journal of Applied Physiology. - : Springer Science and Business Media LLC. - 1439-6327 .- 1439-6319. ; 99, s. 19-26
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies of gender differences in maximum oxygen uptake have come to different conclusions. Limited data exists where the determinants of maximum oxygen uptake have been evaluated in a comprehensive manner. Thus, we examined 248 children (140 boys and 108 girls), aged 7.9-11.1 years. Body composition was determined by dual-energy X-ray absorptiometry, measured variables were total body fat (TBF) and lean body mass (LBM). Maximal oxygen uptake (VO2peak) was measured by indirect calorimetry during a maximal cycle exercise test. Daily physical activity was assessed by accelerometers and duration of vigorous activity per day (VPA) was calculated. Left ventricular inner diastolic diameter (LVDD) was measured by echocardiography. Lung function was evaluated with spirometric testing and whole body plethysmography. Boys had between 8 and 18% higher values than girls for VO2peak, dependent upon whether VO2peak was expressed in absolute values or scaled to body mass, LBM or if allometric scaling was used. In multiple regression analysis absolute values of aerobic fitness were independently related to LBM, maximal heart rate (Max HR), gender, LVDD, and VPA. Furthermore, when VO2peak was scaled to body mass it was independently related to In TBF, Max HR, gender, VPA, and LVDD. Lung function had no relation to VO2peak. Our study concludes that body composition is the main predictor for VO2peak, in children aged 8-11 years, whereas VPA or LVDD has only a modest impact. Existing gender differences in VO2peak cannot be explained only by differences in body composition, physical activity, or heart size.
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| 14. |
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| 15. |
- Dencker, Magnus, et al.
(författare)
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Maximal oxygen uptake versus maximal power output in children
- 2008
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Ingår i: Journal of Sports Sciences. - : Informa UK Limited. - 0264-0414 .- 1466-447X. ; 26:13, s. 1397-1402
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Tidskriftsartikel (refereegranskat)abstract
- Maximal oxygen uptake ([Vdot]O2max) is considered the optimal method to assess aerobic fitness. The measurement of [Vdot]O2max, however, requires special equipment and training. Maximal exercise testing with determination of maximal power output offers a more simple approach. This study explores the relationship between [Vdot]O2max and maximal power output in 247 children (139 boys and 108 girls) aged 7.9-11.1 years. Maximal oxygen uptake was measured by indirect calorimetry during a maximal ergometer exercise test with an initial workload of 30W and 15Wmin-1 increments. Maximal power output was also measured. A sample (n=124) was used to calculate reference equations, which were then validated using another sample (n=123). The linear reference equation for both sexes combined was: [Vdot]O2max (mlmin-1)=96 + 10.6maximal power + 3.5body mass. Using this reference equation, estimated [Vdot]O2max per unit of body mass (mlmin-1kg-1) calculated from maximal power correlated closely with the direct measurement of [Vdot]O2max (r=0.91, P0.001). Bland-Altman analysis gave a mean limits of agreement of 0.22.9 (mlmin-1kg-1) (1s). Our results suggest that maximal power output serves as a good surrogate measurement for [Vdot]O2max in population studies of children aged 8-11 years.
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| 16. |
- Gong, Shaofang, et al.
(författare)
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Radio Architecture for Parallel Processing of Extremely High Speed Data
- 2009
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Ingår i: IEEE International Conference on Ultra-Wideband, ICUWB, Vancouver, Canada, 9-11 Sept.. - : IEEE. - 9781424429301 ; , s. 433-437
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Konferensbidrag (refereegranskat)abstract
- Using our own-developed frequency multiplexing network, a radio architecture for parallel radio signal processing has been proposed for achieving extremely high data rate above 10 Gbit/s. To meet the high requirement on phase linearity, amplitude balance and low noise figure in a very large bandwidth, our own-developed ultra-wideband six-port correlator has been utilized for the modulator and demodulator in the radio architecture.
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| 17. |
- Herbertsson, Pär, et al.
(författare)
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Displaced Mason type I fractures of the radial head and neck in adults: A fifteen- to thirty-three-year follow-up study
- 2005
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Ingår i: Journal of Shoulder and Elbow Surgery. - : Elsevier BV. - 1058-2746. ; 14:1, s. 73-77
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Tidskriftsartikel (refereegranskat)abstract
- Undisplaced radial head and neck fractures are consistently described with no long-term deficits. The aim of this study was to evaluate specifically the long-term outcome of displaced Mason type I fractures, which have not previously described. Twenty women and twelve men, with a mean age of 46 years (range, 22-69 years) when they sustained a displaced Mason type I fracture, were reexamined at a mean of 21 years (range, 15-33 years) after injury. All were treated nonoperatively. Twenty-nine individuals had no subjective complaints, whereas three had occasional elbow pain. There was no objective impairment, and none had elbow osteoarthritis, defined as reduced joint space, whereas there was more radiographic degeneration in the formerly fractured elbow than in the uninjured elbow (85% vs 4%, P < .001). We conclude that the long-term results of nonoperatively treated displaced Mason type I fractures of the radial head and neck are predominantly favorable.
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| 18. |
- Johansson, Karl-Axel, et al.
(författare)
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The quality assurance process for the ARTSCAN head and neck study - a practical interactive approach for QA in 3DCRT and IMRT.
- 2008
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Ingår i: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 87:2, s. 290-9
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Tidskriftsartikel (refereegranskat)abstract
- AIM: This paper describes the quality assurance (QA) work performed in the Swedish multicenter ARTSCAN (Accelerated RadioTherapy of Squamous cell CArcinomas in the head and Neck) trial to guarantee high quality in a multicenter study which involved modern radiotherapy such as 3DCRT or IMRT. MATERIALS AND METHODS: The study was closed in June 2006 with 750 randomised patients. Radiation therapy-related data for every patient were sent by each participating centre to the QA office where all trial data were reviewed, analysed and stored. In case of any deviation from the protocol, an interactive process was started between the QA office and the local responsible clinician and/or physicist to increase the compliance to the protocol for future randomised patients. Meetings and workshops were held on a regular basis for discussions on various trial-related issues and for the QA office to report on updated results. RESULTS AND DISCUSSION: This review covers the 734 patients out of a total of 750 who had entered the study. Deviations early in the study were corrected so that the overall compliance to the protocol was very high. There were only negligible variations in doses and dose distributions to target volumes for each specific site and stage. The quality of the treatments was high. Furthermore, an extensive database of treatment parameters was accumulated for future dose-volume vs. endpoint evaluations. CONCLUSIONS: This comprehensive QA programme increased the probability to draw firm conclusions from our study and may serve as a concept for QA work in future radiotherapy trials where comparatively small effects are searched for in a heterogeneous tumour population.
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| 19. |
- Johansson, Lars, et al.
(författare)
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Lipid Mobilization Following Roux-en-Y Gastric Bypass Examined by Magnetic Resonance Imaging and Spectroscopy
- 2008
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Ingår i: Obesity Surgery. - : Springer Science and Business Media LLC. - 0960-8923 .- 1708-0428. ; 18:10, s. 1297-1304
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Recent developments of magnetic resonance imaging (MRI) and spectroscopy have made it possible to quantify lipid deposited in different tissues. To what extent an improvement of glucose tolerance shortly after Roux-en-Y gastric bypass surgery (RYGBP) is reflected in lipid levels in liver and skeletal muscle, markers of insulin resistance, has not been clarified. METHODS: Whole-body MRI and MR spectroscopy (MRS) of liver and muscle and measurements of biochemical markers of glucose and lipid metabolism were performed at baseline and 1, 6, and 12 months following surgery in seven morbidly obese women. Volumes of adipose tissue depots and liver and muscle lipids were assessed from the MRI/MRS data. RESULTS: At 1 month postoperatively, body mass index and visceral and subcutaneous adipose tissues were reduced by 9%, 26%, and 10%, respectively, whereas no reductions in intrahepatocellular or skeletal intramyocellular lipid concentrations were found. Free fatty acid and beta-hydroxybutyrate levels were elevated two- and sixfold, respectively; glucose and insulin levels were lowered, indicating increased insulin sensitivity. Further weight loss up to 1 year was associated with reductions in all investigated lipid depots investigated, with the exception of the intramyocellular compartment. CONCLUSION: RYGBP causes rapid lipid mobilization from visceral and subcutaneous adipose depots and enhanced free fatty acid flux to the liver. An exceptional disconnection between liver fat and insulin sensitivity occurs in the early dynamic phase after surgery. However, in the late phase, the energy restriction imposed by the surgical procedure also reduces the liver lipids, but not the intramyocellular lipids.
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