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- 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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- Nilsson, Måns, et al.
(författare)
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The missing link : Bringing institutions and politics into energy future studies
- 2011
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Ingår i: Futures. - : Elsevier BV. - 0016-3287 .- 1873-6378. ; 43:10, s. 1117-1128
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Tidskriftsartikel (refereegranskat)abstract
- Energy future studies can be a useful tool for learning about how to induce and manage technical, economic and policy change related to energy supply and use. The private sector has successfully deployed them for strategic planning, examining key parameters such as markets, competition and consumer trends. However in public policy, most energy future studies remain disconnected from policy making. One reason is that they often ignore the key political and institutional factors that underpin much of the anticipated, wished-for or otherwise explored energy systems developments. Still, we know that institutions and politics are critical enablers or constraints to technical and policy change. This paper examines how analytical insights into political and institutional dynamics can enhance energy future studies. It develops an approach that combines systems-technical change scenarios with political and institutional analysis. Using the example of a backcasting study dealing with the long term low-carbon transformation of a national energy system, it applies two levels of institutional and political analysis; at the level of international regimes and at the level of sectoral policy, and examines how future systems changes and policy paths are conditioned by institutional change processes. It finds that the systematic application of these variables significantly enhances and renders more useful backcasting studies of energy futures.
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- Zackrisson, Björn, et al.
(författare)
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Two-year results from a Swedish study on conventional versus accelerated radiotherapy in head and neck squamous cell carcinoma - The ARTSCAN study
- 2011
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Ingår i: Radiotherapy and Oncology. - : Elsevier. - 0167-8140 .- 1879-0887. ; 100:1, s. 41-48
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose: Studies on accelerated fractionation (AF) in head and neck cancer have shown increased local control and survival compared with conventional fractionation (CF), while others have been non-conclusive. In 1998 a national Swedish group decided to perform a randomised controlled clinical study of AF. Materials and methods: Patients with verified squamous cell carcinoma of the oral cavity, oropharynx, larynx (except glottic T1-T2, N0) and hypopharynx were included. Patients with prior chemotherapy or surgery were excluded. Patients were randomised to either CF (2Gy/day, 5days/week for 7 weeks, total dose 68Gy) or to AF (1.1Gy+2.0Gy/day, 5days/week for 4.5weeks, total dose 68Gy). An extensive quality assurance protocol was followed throughout the study. The primary end point was loco-regional tumour control (LRC) at two years after treatment. RESULTS: The study was closed in 2006 when 750 patients had been randomised. Eighty-three percent of the patients had stages III-IV disease. Forty eight percent had oropharyngeal, 21% laryngeal, 17% hypopharyngeal and 14% oral cancers. There were no significant differences regarding overall survival (OS) or LRC between the two regimens. The OS at two years was 68% for AF and 67% for CF. The corresponding figures for LRC were 71% and 67%, respectively. There was a trend towards improved LRC for oral cancers treated (p=0.07) and for large tumours (T3-T4) (p=0.07) treated with AF. The AF group had significantly worse acute reactions, while there was no significant increase in late effects. Conclusion: Overall the AF regimen did not prove to be more efficacious than CF. However, the trend towards improved results in AF for oral cancers needs to be further investigated.
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- Eriksson, Lars-Ove, et al.
(författare)
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The Arctic charr story: development of subarctic freshwater fish farming in Sweden
- 2010
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Ingår i: Hydrobiologia. - : Springer Science and Business Media LLC. - 0018-8158 .- 1573-5117. ; 650, s. 265-274
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Forskningsöversikt (refereegranskat)abstract
- We present an overview of 27 years of experience of domestication and farming of Arctic charr (Salvelinus alpinus) in Sweden. The domestication process included an evaluation of suitable strains for farming, a breeding programme and the study of the biological and behavioural characteristics of the species. Traits of three different Arctic charr populations differing in ecology and appearance were compared during initial 2-year trials under farming conditions. The best-performing population with respect to the growth rate and the lowest frequency of early sexual maturation was a piscivore form and this became the foundation for a breeding programme intended to select for an Arctic charr strain suitable for farming. After 23 years and 7 generations, our selective breeding has resulted in a fast-growing, late-maturing strain much appreciated by farmers. The biological and behavioural characteristics studied included annual and diel locomotor activity, feeding, social and thermal behaviour. Applying our findings in these areas has greatly improved both profits and conditions for the fish. Other investigations have focused on the application and further evaluation of the results from research in practical farming trials, such as evaluation of growth at different farms with different temperature conditions, optimal time and stocking density for start-feeding and evaluation of different feeding schedules. In Sweden, Arctic charr is mainly farmed in net pens situated in nutritionally depleted and extremely unproductive water reservoirs formed by damming rivers to create electric power. Judicious farming of Arctic charr in such reservoirs can restore their nutritional and productivity state to that which existed before regulation. Site selection criteria for Arctic charr farming in such waters have been developed. The development of intensive farming of Arctic charr in Sweden is discussed together with current limitations and future possibilities.
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- Grigelioniene, Giedre, et al.
(författare)
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Analysis of short stature homeobox-containing gene ( SHOX) and auxological phenotype in dyschondrosteosis and isolated Madelung deformity
- 2001
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Ingår i: Human Genetics. - : Springer Science and Business Media LLC. - 1432-1203 .- 0340-6717. ; 109:5, s. 551-558
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Tidskriftsartikel (refereegranskat)abstract
- Dyschondrosteosis (DCO; also called Leri-Weill syndrome) is a skeletal dysplasia characterised by disproportionate short stature because of mesomelic shortening of the limbs. Madelung deformity is a feature of DCO that is distinctive, variable in expressivity and frequently observed. Mutations of the SHOX (short stature homeobox-containing) gene have been previously described as causative in DCO. Isolated Madelung deformity (IMD) without the clinical characteristics of DCO has also been described in sporadic and a few familial cases but the genetic defect underlying IMD is unknown. In this study, we have examined 28 probands with DCO and seven probands with IMD for mutations in the SHOX gene by using polymorphic CA-repeat analysis, fluorescence in situ hybridisation (FISH), Southern blotting, direct sequencing and fibre-FISH analyses. This was combined with auxological examination of the probands and their family members. Evaluation of the auxological data showed a wide intra- and interfamilial phenotype variability in DCO. Out of 28 DCO probands, 22 (79%) were shown to have mutations in the SHOX gene. Sixteen unrelated DCO families had SHOX gene deletions. Four novel DCO-associated mutations were found in different families. In two additional DCO families, the previously described nonsense mutation (Arg195Stop) was detected. We conclude that mutations in the SHOX gene are the major factor in the pathogenesis of DCO. In a female proband with severe IMD and her unaffected sister, we detected an intrachromosomal duplication of the SHOX gene.
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- Jahnke, Marlene, et al.
(författare)
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Seascape genetics and biophysical connectivity modelling support conservation of the seagrass Zostera marina in the Skagerrak-Kattegat region of the eastern North Sea
- 2018
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Ingår i: Evolutionary Applications. - : Wiley. - 1752-4563 .- 1752-4571. ; 11:5, s. 645-661
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Tidskriftsartikel (refereegranskat)abstract
- Maintaining and enabling evolutionary processes within meta-populations are critical to resistance, resilience and adaptive potential. Knowledge about which populations act as sources or sinks, and the direction of gene flow, can help to focus conservation efforts more effectively and forecast how populations might respond to future anthropogenic and environmental pressures. As a foundation species and habitat provider, Zostera marina (eelgrass) is of critical importance to ecosystem functions including fisheries. Here, we estimate connectivity of Z.marina in the Skagerrak-Kattegat region of the North Sea based on genetic and biophysical modelling. Genetic diversity, population structure and migration were analysed at 23 locations using 20 microsatellite loci and a suite of analytical approaches. Oceanographic connectivity was analysed using Lagrangian dispersal simulations based on contemporary and historical distribution data dating back to the late 19th century. Population clusters, barriers and networks of connectivity were found to be very similar based on either genetic or oceanographic analyses. A single-generation model of dispersal was not realistic, whereas multigeneration models that integrate stepping-stone dispersal and extant and historic distribution data were able to capture and model genetic connectivity patterns well. Passive rafting of flowering shoots along oceanographic currents is the main driver of gene flow at this spatial-temporal scale, and extant genetic connectivity strongly reflects the ghost of dispersal past sensu Benzie, . The identification of distinct clusters, connectivity hotspots and areas where connectivity has become limited over the last century is critical information for spatial management, conservation and restoration of eelgrass.
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- Jonsson, Per R., 1957, et al.
(författare)
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Particle depletion above experimental bivalve beds: In situ measurements and numerical modeling of bivalve filtration in the boundary layer
- 2005
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Ingår i: Limnology and Oceanography. - 0024-3590. ; 50:6, s. 1989-1998
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Tidskriftsartikel (refereegranskat)abstract
- Suspension feeders may deplete the near-bed layer of food particles, limiting growth of downstream, individuals. In a field experiment, we examined food depletion above a bed with bivalves (Cerastoderma edule) compared to beds devoid of Suspension feeders and how depletion depended on boundary-layer flow. Water above the test plots was sampled with an array of artificial siphons mimicking bivalve inhalant flow. Along the 3-m, bed with bivalves, chlorophyll a (Chl a) in the near-bed layer was depleted by 5-30%. Contrary to expectations from turbulent mixing, Chl a depletion increased with friction velocity. To explore the possibility that the bending of the exhalant jet in a strong boundary-layer flow Could lead to this depletion, we studied (lie advection and turbulent diffusion of exhalant water by the injection Of fluorescent dye through artificial siphons. The plume of fluorescent dye indicated that the interaction between the exhalant jet and horizontal water flow strongly affected the near-bed mixing of depleted water. At high ratios between jet and friction velocities (VR), the vertical momentum of the exhalant jet reduced the proportion of exhalant water reaching downstream neighbors. A hydrodynamic model incorporating inhalant and exhalant flows in the boundary layer predicted that exhalant jet flow lines reach the bed immediately downstream when the VR ratio is <20, potentially increasing refiltration at higher flow speeds due to jet bending. However, the model could not reproduce the observed increase in refiltration with increasing, friction velocity in simulations of aggregated filtration in a bed of bivalves.
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