| 1. |
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| 2. |
- Barthelmie, Rebecca, et al.
(författare)
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ENDOW (efficient development of offshore wind farms): modelling wake and boundary layer interactions
- 2004
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Ingår i: Wind Energy. - : Wiley. - 1095-4244 .- 1099-1824. ; 7, s. 225-245
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Tidskriftsartikel (refereegranskat)abstract
- While experience gained through the offshore wind energy projects currently operating is valuable, a major uncertainty in estimating power production lies in the prediction of the dynamic links between the atmosphere and wind turbines in offshore regimes. The objective of the ENDOW project was to evaluate, enhance and interface wake and boundary layer models for utilization offshore. The project resulted in a significant advance in the state of the art in both wake and marine boundary layer models, leading to improved prediction of wind speed and turbulence profiles within large offshore wind farms. Use of new databases from existing offshore wind farms and detailed wake profiles collected using sodar provided a unique opportunity to undertake the first comprehensive evaluation of wake models in the offshore environment. The results of wake model performance in different wind speed, stability and roughness conditions relative to observations provided criteria for their improvement. Mesoscale model simulations were used to evaluate the impact of thermal flows, roughness and topography on offshore wind speeds. The model hierarchy developed under ENDOW forms the basis of design tools for use by wind energy developers and turbine manufacturers to optimize power output from offshore wind farms through minimized wake effects and optimal grid connections. The design tools are being built onto existing regional-scale models and wind farm design software which was developed with EU funding and is in use currently by wind energy developers.
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| 3. |
- Bergström, Hans, 1952-, et al.
(författare)
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Wind power in forests : wind and effects on loads
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Within the project V-312, Wind power in forests, researchers and a PhD student at Uppsala University, WeatherTech Scandinavia, the Royal Institute of Technology (KTH), DTU Wind Energy in Denmark and Teknikgruppen have been cooperating. Within the project atmospheric turbulence measurements with high vertical resolution have been done, also down between the trees, to make it possible to give better theoretical descriptions of the observed properties. Several mesoscale models have also been used to model the above forest winds. The atmospheric measurements have been complemented by wind tunnel measurements using a wind tunnel floor designed with small cylindrical wooden sticks that should simulate the effect of the trees generating a known momentum sink able to affect the flow. The combined new knowledge about the forest boundary layer wind and turbulence properties have been used as input to a dynamical wind turbine computer model, used to simulate the turbine load response to the turbulent wind field.
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| 4. |
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| 5. |
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| 6. |
- Fritzell, Peter, et al.
(författare)
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Bacteria : back pain, leg pain and Modic sign—a surgical multicentre comparative study
- 2019
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Ingår i: European spine journal. - : Springer. - 0940-6719 .- 1432-0932. ; 28:12, s. 2981-2989
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To compare bacterial findings in pain-generating degenerated discs in adults operated on for lumbar disc herniation (LDH), and mostly also suffering from low back pain (LBP), with findings in adolescent patients with non-degenerated non-pain-generating discs operated on for scoliosis, and to evaluate associations with Modic signs on magnetic resonance imaging (MRI). Cutibacterium acnes (Propionibacterium acnes) has been found in painful degenerated discs, why it has been suggested treating patients with LDH/LBP with antibiotics. As multidrug-resistant bacteria are a worldwide concern, new indications for using antibiotics should be based on solid scientific evidence.Methods: Between 2015 and 2017, 40 adults with LDH/LBP (median age 43, IQR 33–49) and 20 control patients with scoliosis (median age 17, IQR 15–20) underwent surgery at seven Swedish hospitals. Samples were cultured from skin, surgical wound, discs and vertebrae. Genetic relatedness of C. acnes isolates was investigated using single-nucleotide polymorphism analysis. DNA samples collected from discs/vertebrae were analysed using 16S rRNA-based PCR sequencing. MRI findings were assessed for Modic changes.Results: No bacterial growth was found in 6/40 (15%) LDH patients, compared with 3/20 (15%) scoliosis patients. Most positive samples in both groups were isolated from the skin and then from subcutis or deep within the wound. Of the four disc and vertebral samples from each of the 60 patients, 235/240 (98%) were DNA negative by bacterial PCR. A single species, C. acnes, was found exclusively in the disc/vertebra from one patient in each group. In the LDH group, 29/40 (72%) patients had at least one sample with growth of C. acnes, compared to 14/20 (70%) in the scoliosis group. Bacterial findings and Modic changes were not associated.Conclusions: Cutibacterium acnes found in discs and vertebrae during surgery for disc herniation in adults with degenerated discs may be caused by contamination, as findings in this group were similar to findings in a control group of young patients with scoliosis and non-degenerated discs. Furthermore, such findings were almost always combined with bacterial findings on the skin and/or in the wound. There was no association between preoperative Modic changes and bacterial findings. Antibiotic treatment of lumbar disc herniation with sciatica and/or low back pain, without signs of clinical discitis/spondylitis, should be seriously questioned.
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| 7. |
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| 8. |
- Genberg, Johan, et al.
(författare)
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Light-absorbing carbon in Europe - measurement and modelling, with a focus on residential wood combustion emissions
- 2013
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 13:17, s. 8719-8738
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Tidskriftsartikel (refereegranskat)abstract
- The atmospheric concentration of elemental carbon (EC) in Europe during the six-year period 2005-2010 has been simulated with the EMEP MSC-W model. The model bias compared to EC measurements was less than 20% for most of the examined sites. The model results suggest that fossil fuel combustion is the dominant source of EC in most of Europe but that there are important contributions also from residential wood burning during the cold seasons and, during certain episodes, also from open biomass burning (wildfires and agricultural fires). The modelled contributions from open biomass fires to ground level concentrations of EC were small at the sites included in the present study, <3% of the long-term average of EC in PM10. The modelling of this EC source is subject to many uncertainties, and it was likely underestimated for some episodes. EC measurements and modelled EC were also compared to optical measurements of black carbon (BC). The relationships between EC and BC (as given by mass absorption cross section, MAC, values) differed widely between the sites, and the correlation between observed EC and BC is sometimes poor, making it difficult to compare results using the two techniques and limiting the comparability of BC measurements to model EC results. A new bottom-up emission inventory for carbonaceous aerosol from residential wood combustion has been applied. For some countries the new inventory has substantially different EC emissions compared to earlier estimates. For northern Europe the most significant changes are much lower emissions in Norway and higher emissions in neighbouring Sweden and Finland. For Norway and Sweden, comparisons to source-apportionment data from winter campaigns indicate that the new inventory may improve model-calculated EC from wood burning. Finally, three different model setups were tested with variable atmospheric lifetimes of EC in order to evaluate the model sensitivity to the assumptions regarding hygroscopicity and atmospheric ageing of EC. The standard ageing scheme leads to a rapid transformation of the emitted hydrophobic EC to hygroscopic particles, and generates similar results when assuming that all EC is aged at the point of emission. Assuming hydrophobic emissions and no ageing leads to higher EC concentrations. For the more remote sites, the observed EC concentration was in between the modelled EC using standard ageing and the scenario treating EC as hydrophobic. This could indicate too-rapid EC ageing in the model in relatively clean parts of the atmosphere.
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| 9. |
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| 10. |
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| 11. |
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| 12. |
- Nilsson, Erik, 1983-, et al.
(författare)
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Evaluating humidity and sea salt disturbances on CO2 flux measurements
- 2018
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Ingår i: Journal of Atmospheric and Oceanic Technology. - 0739-0572 .- 1520-0426. ; 35, s. 859-875
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Tidskriftsartikel (refereegranskat)abstract
- Global oceans are an important sink of atmospheric carbon dioxide (CO2). Therefore, understanding the air-sea flux of CO2 is a vital part in describing the global carbon balance. Eddy covariance (EC) measurements are often used to study CO2 fluxes from both land and ocean. CO2 are usually measured with infrared absorption sensors, which at the same time measure water vapor. Studies have shown that presence of water vapor fluctuations in the sampling air potentially result in erroneous CO2 flux measurements due to cross-sensitivity of the sensor. Here we compare measured CO2 fluxes from both enclosed path Li-Cor 7200 sensors and open-path Li-Cor 7500 instruments from an inland measurement site and a marine site. We also introduce new quality control criteria based upon a Relative Signal Strength Indicator (RSSI). The sampling gas in one of the Li-Cor 7200 instruments was dried by means of a multi-tube diffusion dryer so that the water vapor fluxes were close to zero. With this setup we investigated the effect that cross-sensitivity of the CO2 signal to water vapor can have on the CO2 fluxes. The dryer had no significant effect on the CO2 fluxes. We tested the hypothesis that the cross-sensitivity effect is caused by hygroscopic particles such as sea salt by spraying a saline solution on the windows of the Li-Cor 7200 instruments during the inland field test. Our results confirm earlier findings that sea salt contamination can affect CO2 fluxes significantly and confirm earlier findings, that drying the sampling air for the gas analyzer is an effective method to reduce this signal contamination.
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| 13. |
- Pettersson, Gunilla, et al.
(författare)
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Strong and bulky paperboard sheets from surface modified CTMP, manufactured at low energy
- 2015
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Ingår i: Nordic Pulp & Paper Research Journal. - 0283-2631 .- 2000-0669. ; 30:2, s. 318-324
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Tidskriftsartikel (refereegranskat)abstract
- A description is given regarding methods used to manufacture strong and bulky sheets from furnishes based on a broad range of surface modified CTMP qualities. Starch and CMC are adsorbed on the fibre surfaces using a multilayer or a MIX concept. It is shown that both the in-plane and out-of-plane strength for the CTMP based sheets after such surface treatment can be more than doubled at a maintained density. This can be utilized to improve bending stiffness or to reduce the basis weight in multi-ply paperboards.
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| 14. |
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| 15. |
- Abdellah, Tebani, et al.
(författare)
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Integration of molecular profiles in a longitudinal wellness profiling cohort.
- 2020
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Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- An important aspect of precision medicine is to probe the stability in molecular profiles among healthy individuals over time. Here, we sample a longitudinal wellness cohort with 100 healthy individuals and analyze blood molecular profiles including proteomics, transcriptomics, lipidomics, metabolomics, autoantibodies andimmune cell profiling, complementedwith gut microbiota composition and routine clinical chemistry. Overall, our results show high variation between individuals across different molecular readouts, while the intra-individual baseline variation is low. The analyses show that each individual has a unique and stable plasma protein profile throughout the study period and that many individuals also show distinct profiles with regards to the other omics datasets, with strong underlying connections between the blood proteome and the clinical chemistry parameters. In conclusion, the results support an individual-based definition of health and show that comprehensive omics profiling in a longitudinal manner is a path forward for precision medicine.
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| 16. |
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| 17. |
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| 18. |
- Anderbrant, Olle, et al.
(författare)
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Attraction of Male Pine Sawflies, Diprion jingyuanensis, to Synthetic Pheromone Candidates: Synergism between Two Stereoisomers
- 2023
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Ingår i: Forests. - : MDPI. - 1999-4907. ; 14:6
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Tidskriftsartikel (refereegranskat)abstract
- The pine sawfly Diprion jingyuanensis Xiao and Zhang (Hymenoptera: Diprionidae) is a serious pest of Pinus tabulaeformis Carr. in the Shanxi, Gansu, and Inner Mongolia provinces in P. R. China. The sex pheromone of D. jingyuanensis was shown to be the propionate ester of 3,7-dimethyl-2-tridecanol. Virgin females contained an approximate 1:3 blend of the pheromone precursors erythro-(2S,3S,7R/S and 2R,3R,7R/S)-3,7-dimethyl-2-tridecanol and threo-(2S,3R,7R/S and 2R,3S,7R/S)-3,7-dimethyl-2-tridecanol, but the exact stereoisomers were not determined. Males responded the strongest to the propionate ester of the two threo-isomers, (2S,3R,7R) and (2S,3R,7S), in electroantennogram (EAG) recordings, followed by a significant EAG response to the (2S,3R,7R) propionate of diprionol (pheromone component of D. similis), whereas the remaining two isomers (2S,3S,7S and 2S,3S,7R) of the propionate ester of 3,7-dimethyl-2-tridecanol and the acetate of the (2S,3R,7R) isomer (one of the two pheromone components of D. pini) did not elicit any significant increase in antennal response. In the field, the strongly EAG-active (2S,3R,7R)-isomer alone was only weakly (but significantly) attractive to D. jingyuanensis males at 100 & mu;g, while the equally EAG- active (2S,3R,7S)-isomer alone at the same loading was 8-14 times more attractive than was the (2S,3R,7R)-isomer alone. Traps baited with the same amounts of the two threo-isomers ((2S,3R,7R) and (2S,3R,7S), 100 & mu;g + 100 & mu;g) caught significantly more males than did traps baited with other isomers, either of the two isomers alone or other proportions of the two isomers. Thus, the (2S,3R,7S)-isomer is considered as a strong and essential sex-attractant component for D. jingyuanensis males, whereas the (2S,3R,7R)-isomer is a weak but synergistic sex-attractant. This is one of the few examples of a pine sawfly responding significantly stronger to a binary blend of stereoisomers in a synergistic fashion than to a single stereoisomer alone.
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| 19. |
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| 20. |
- Anderbrant, Olle, et al.
(författare)
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Release of sex pheromone and its precursors in the pine sawfly Diprion pini (Hym., Diprionidae)
- 2005
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Ingår i: Chemoecology. - : Springer Science and Business Media LLC. - 0937-7409 .- 1423-0445. ; 15:3, s. 147-151
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Tidskriftsartikel (refereegranskat)abstract
- The first identification of a sex pheromone of a pine sawfly (Hymenoptera, Diprionidae) dates back almost thirty years. Since then, female-produced pheromones of over twenty diprionid species have been investigated by solvent extraction followed by separation and identification. However, no study has shown what the females actually release. Collection of airborne compounds using absorbtion on charcoal filter as well as solid phase microextraction (SPME) followed by analysis employing gas chromatography combined with mass spectrometry (GC-MS), revealed an unusual system in Diprion pini, in which the pheromone precursor alcohol, 3,7-dimethyl-2-tridecanol, is released together with acetic, propionic, butyric and isobutyric acids. The corresponding acetate, propionate and butyrate esters of 3,7-dimethyl-2-tridecanol were also found in the samples. All esters were electrophysiologically active, and the propionate and isobutyrate were attractive in trapping experiments. Based on these and earlier reported results, it seems that at least in part of its range, the pheromone response of D. pini is not very specific with regard to the functional group, as long as this is an ester.
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| 21. |
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| 22. |
- Andresen Bergström, Moa, 1978, et al.
(författare)
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A skin-like cytochrome P450 cocktail activates prohaptens to contact allergenic metabolites.
- 2007
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Ingår i: The Journal of investigative dermatology. - : Elsevier BV. - 1523-1747 .- 0022-202X. ; 127:5, s. 1145-53
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Tidskriftsartikel (refereegranskat)abstract
- Allergic contact dermatitis is a complex syndrome representing immunological responses to cutaneous exposure to protein-reactive chemicals. Although many contact sensitizers directly can elicit this disorder, others (prohaptens) require activation. Knowledge regarding the activating mechanisms remains limited, but one possibility is metabolic activation by cytochrome P450 (CYP) enzymes in the skin. We have, after quantitative reverse transcriptase-PCR studies of the CYP content in 18 human skin samples, developed an enriched skin-like recombinant human (rh) CYP cocktail using CYP1A1, 1B1, 2B6, 2E1, and 3A5. To validate the rhCYP cocktail, a prohaptenic conjugated diene ((5R)-5-isopropenyl-2-methyl-1-methylene-2-cyclohexene) was investigated using: the skin-like rhCYP cocktail, a liver-like rhCYP cocktail, single rhCYP enzymes, liver microsomes, keratinocytes, and a dendritic cell (DC) assay. The diene was activated to sensitizing epoxides in all non-cell-based incubations including the skin-like rhCYP cocktail. An exocyclic epoxide metabolite ((7R)-7-isopropenyl-4-methyl-1-oxaspiro[2.5]oct-4-ene) was found to be mainly responsible for the allergenic activity of the diene. This epoxide also induced pronounced DC activation indicated by upregulation of IL-8. The skin-like rhCYP cocktail provides a simplified alternative to using skin tissue preparations in mechanistic studies of CYP-mediated skin metabolism of prohaptens and offers the future possibility of designing in vitro predictive assays for assessment of allergenic activity of prohaptens.
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| 23. |
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| 24. |
- Arnqvist, Johan, et al.
(författare)
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Canopy waves, observations and predictions from lineartheory
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this paper the existence of canopy waves is examined using measurements from a 138 m high tower placed in a forest. Characteristics of the waves are examined in relation to wind energy. Using wavelet analysis it is shown that when the wave signal is clear, the phase lag between horizontal and vertical velocity is close to 90 degrees, which limits the contribution of the waves to themomentum flux. Results from numerical solution of linear wave equations is shown to agree with measurements in terms of wave period and the vertical shape of the wave amplitude. Linear analysis and measurements suggests that Kelvin-Helmholtz instability causes unstable wave growth and that the most unstable wave number normally has a period of 10-100 s. In addition to the Kelvin-Helmholtz instability, the linear analysis predicts that instabilities of the Holmboe kind, with higher frequency, can develop over forests in certain conditions.
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| 25. |
- Arnqvist, Johan, 1985-, et al.
(författare)
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Flux-profile relation with roughness sublayer correction
- 2015
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Ingår i: Quarterly Journal of the Royal Meteorological Society. - : Wiley. - 0035-9009 .- 1477-870X. ; 141:689, s. 1191-1197
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Tidskriftsartikel (refereegranskat)abstract
- Calculation of momentum flux using Monin–Obukhov similarity theory over forested areas is well known to underestimate the flux. Several suggestions of corrections to the standard flux-profile expression have been proposed in order to increase the magnitude of turbulent flux. The aim of this article is to find a simple, analytical representation for the characteristics of the flow within the canopy layer and the surface layer, including the roughness sublayer. A new form of the roughness sublayer correction is proposed, based on the desire to connect the shape of the roughness sublayer correction to forest characteristics. The new flux-profile relation can be used to find the flux or the wind profile whenever simple and fast estimations are needed, as for mesoscale modelling, scalar transport models, or sound propagation models.
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| 26. |
- Arnqvist, Johan, 1985-
(författare)
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Mean Wind and Turbulence Conditions in the Boundary Layer above Forests
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- As wind turbines have grown, new installation areas become possible. Placing wind turbines in forested landscapes introduce uncertainties to the wind resource estimation. Even though close-to-canopy processes have been studied intensively during the last thirty years, the focus has mostly been on exchange processes and the height span of the studies has been below the rotor of a modern wind turbine.This thesis contains analysis of new measurements from a 138 m high tower in a forested landscape. The previous knowledge of near-canopy processes is extended to the region above the roughness sublayer. It is shown that above the roughness sublayer, the surface layer behaves as over low vegetation, and Monin-Obukhov similarity is shown to hold for several variables. However, in stable stratification, effects that could be linked to the boundary layer depth are shown to be present in the measurements. These include wind turning with height, the behaviour of the turbulence length scale and the curvature of the wind profile.Two new analytical models are presented in the thesis. One is a flux-profile expression in the roughness sublayer, which allows for analytical integration of the wind gradient. The model suggests that the roughness-sublayer effect depends on stratification and that the aerodynamic roughness length changes with stability. A decrease of roughness length in stable stratification is confirmed with a new method to determine the roughness length using measurements from the 138 m tower.The other model determines the spectral tensor in stable stratification using analytical solution to the rapid distortion equations for stratified shear flow, with homogeneous stratification and shear. By using a formulation for the integration time of the distortions of an isotropic spectrum, a model is derived which provides the cross spectra of velocity and temperature at any two given points in space.Finally the existence of waves in the wind over forests is investigated and it is concluded that the Kelvin-Helmholtz instability can create waves which are coherent in time and exist over the entire height span of wind turbine rotors. Linear wave theory is shown to be able to explain certain features of the waves.
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| 27. |
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| 28. |
- Arnqvist, Johan, et al.
(författare)
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Wind Statistics from a Forested Landscape
- 2015
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Ingår i: Boundary-layer Meteorology. - : Springer Science and Business Media LLC. - 0006-8314 .- 1573-1472. ; 156:1, s. 53-71
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Tidskriftsartikel (refereegranskat)abstract
- An analysis and interpretation of measurements from a 138-m tall tower located in a forested landscape is presented. Measurement errors and statistical uncertainties are carefully evaluated to ensure high data quality. A 40 wide wind-direction sector is selected as the most representative for large-scale forest conditions, and from that sector first-, second- and third-order statistics, as well as analyses regarding the characteristic length scale, the flux-profile relationship and surface roughness are presented for a wide range of stability conditions. The results are discussed with focus on the validity of different scaling regimes. Significant wind veer, decay of momentum fluxes and reduction in shear length scales with height are observed for all stability classes, indicating the influence of the limited depth of the boundary layer on the measured profiles. Roughness sublayer characteristics are however not detected in the presented analysis. Dimensionless gradients are shown to follow theoretical curves up to 100 m in stable conditions despite surface-layer approximations being invalid. This is attributed to a balance of momentum decay and reduced shear length scale growth with height. The wind profile shows a strong stability dependence of the aerodynamic roughness length, with a 50 % decrease from neutral to stable conditions.
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| 29. |
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| 30. |
- Bagdonaite, Ieva, et al.
(författare)
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Glycoengineered keratinocyte library reveals essential functions of specific glycans for all stages of HSV-1 infection
- 2023
-
Ingår i: Nature Communications. - 2041-1723. ; 14:1
-
Tidskriftsartikel (refereegranskat)abstract
- Viral and host glycans represent an understudied aspect of host-pathogen interactions, despite potential implications for treatment of viral infections. This is due to lack of easily accessible tools for analyzing glycan function in a meaningful context. Here we generate a glycoengineered keratinocyte library delineating human glycosylation pathways to uncover roles of specific glycans at different stages of herpes simplex virus type 1 (HSV-1) infectious cycle. We show the importance of cellular glycosaminoglycans and glycosphingolipids for HSV-1 attachment, N-glycans for entry and spread, and O-glycans for propagation. While altered virion surface structures have minimal effects on the early interactions with wild type cells, mutation of specific O-glycosylation sites affects glycoprotein surface expression and function. In conclusion, the data demonstrates the importance of specific glycans in a clinically relevant human model of HSV-1 infection and highlights the utility of genetic engineering to elucidate the roles of specific viral and cellular carbohydrate structures.
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| 31. |
- Bailey, Leslie, et al.
(författare)
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Small molecule inhibitors of type III secretion in Yersinia block the Chlamydia pneumoniae infection cycle
- 2007
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Ingår i: FEBS Letters. - : Elsevier. - 0014-5793 .- 1873-3468. ; 581:4, s. 587-595
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Tidskriftsartikel (refereegranskat)abstract
- Intracellular parasitism by Chlamydiales is a complex process involving transmission of metabolically inactive particles that differentiate, replicate, and re-differentiate within the host cell. A type three secretion system (T3SS) has been implicated in this process. We have here identified small molecules of a chemical class of acylated hydrazones of salicylaldehydes that specifically blocks the T3SS of Chlamydia. These compounds also affect the developmental cycle showing that the T3SS has a pivotal role in the pathogenesis of Chlamydia. Our results suggest a previously unexplored avenue for development of novel anti-chlamydial drugs.
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| 32. |
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| 33. |
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| 34. |
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| 35. |
- Barthelmie, Rebecca, et al.
(författare)
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ENDOW: Efficient Development of Offshore Windfarms
- 2003
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Ingår i: Proceedings from Offshore Wind Energy in Meditteranean and Other Seas OWEMES2003, Naples, Italy, 10-12 April 2003.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 36. |
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| 37. |
- Bergqvist, Göran, et al.
(författare)
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Forage availability and moose winter browsing in forest landscapes
- 2018
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 419-420, s. 170-178
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Tidskriftsartikel (refereegranskat)abstract
- In a large-scale survey, comprising 38 landscapes throughout Sweden, we measured winter forage availability and use by moose within different forest- and land types, and also at three different spatial scales: plot, tract and area.Measured as percent cover of browse species within moose browsing range, young forests contained significantly more browse (16.5 +/- 1.20%: mean +/- SE) compared with older forests (6.7 +/- 0.57%) or non-forest land (5.9 +/- 0.67%). Total cover of browse species increased with increasing mean tree height in forests, and peaked at around 22% when the trees were 3-5 m. The relative consumption was highest in young forests (9.2 +/- 0.98%) compared with non-forest land (7.8 +/- 1.40%) or older forests (5.8 +/- 0.78%). The selection order did not vary much among forest- or land types, with aspen, willows, rowan and oak being the most selected species.A multiple regression, including four independent variables (moose index, cover of Scots pine, cover of other species and temperature sum) explained 45% (young forests), 18% (older forests) and 36% (non-forest land) of the variation in relative consumption. In young forests, moose index and cover of Scots pine accounted for 40 and 44%, respectively, of the explained variation. Model selection, using AICc, further emphasized the importance of moose index and cover of Scots pine, as these variables were included in the most parsimonious models for all forest- and land types.At the tract level, we recorded a proportional relationship between total cover of browse species and absolute consumption, suggesting an ideal free distribution. Taking into account the availability of forage, the degree of browsing and the proportion of each land type in the landscape, we calculated that 44.3% of the total forage consumption occurred in young forests, 42.3% in older forests and 13.4% in non-forest land.Our main conclusions are that moose conform to an ideal free distribution based on availability of forage within the landscape, and that all forest- and land types, not just young forests, are important as sources of browse for moose. Thus, it may be possible to release the browsing pressure on damage-sensitive young forests by increasing the food supply in other forest- and land types. Furthermore, managers needs to consider both the size of the moose population and the amounts of browse in the landscape when deciding on prudent management actions.
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| 38. |
- Bergström, Annika, et al.
(författare)
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Hormonal concentrations in bitches with primary uterine inertia
- 2010
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Ingår i: Theriogenology. - : Elsevier BV. - 0093-691X .- 1879-3231. ; 73, s. 1068-1075
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Tidskriftsartikel (refereegranskat)abstract
- Normal labor is accompanied by sequential changes in blood concentrations of prostaglandin F2 alpha (measured as 15-ketodihydro-PGF2 alpha = PGFM). progesterone, estradiol, oxytocin, vasopressin, and of elevated cortisol levels The aim of this study was to investigate hormone concentrations in dogs diagnosed with primary uterine inertia before and during treatment by cesarian section. The hypothesis was the dogs would have abnormally low plasma concentrations in one or several of the hormones involved in parturition The study comprised seven bitches with total primary uterine inertia (dystocia group) treated with cesarian section and SIX healthy bitches (control group) subjected to planned cesarean section Blood samples were taken before anesthesia, before surgery started, on delivery of the first puppy and on delivery of the last puppy The progesterone PGFM ratio in plasma was higher in the dystocia group than in the control group. but the serum estradiol concentration did not differ between groups The plasma concentrations of oxytocin and vasopressin increased in both groups when the first puppies were delivered, but both hormones were more elevated in the control group than in the dystocia group on delivery of the last puppies The plasma cortisol concentration increased to the same level in both groups In conclusion, the ratio between progesterone and PGFM was higher and the oxytocin and vasopressin concentrations lower in the dystocia clogs than in the control dogs The findings indicate that these hormones are involved in the pathophysiology of total primary uterine inertia in bitches (C) 2010 Elsevier Inc. All rights reserved
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| 39. |
- Bergström, Beatrice, et al.
(författare)
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Methotrexate inhibits effects of platelet-derived growth factor and interleukin-1β on rheumatoid arthritis fibroblast-like synoviocytes
- 2018
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Ingår i: Arthritis Research and Therapy. - : Springer Science and Business Media LLC. - 1478-6354 .- 1478-6362. ; 20:49
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Tidskriftsartikel (refereegranskat)abstract
- Background: A key feature of joints in rheumatoid arthritis (RA) is the formation of hyperplastic destructive pannus tissue, which is orchestrated by activated fibroblast-like synoviocytes (FLS). We have demonstrated that the RA risk gene and tumor suppressor Limb bud and heart development (LBH) regulates cell cycle progression in FLS. Methotrexate (MTX) is the first-line treatment for RA, but its mechanisms of action remain incompletely understood. Here, we studied the effects of MTX on mitogen-induced FLS proliferation and expression of cell cycle regulators in vitro. Methods: Primary FLS from patients with RA or osteoarthritis were stimulated with the mitogen platelet-derived growth factor (PDGF) and the cytokine interleukin-1β (IL-1β) in the presence or absence of MTX. Cells were then subjected to qPCR for gene expression and cell cycle analysis by flow cytometry. Results: Stimulation with PDGF and IL-1β increased the percentage of FLS in the G2/M phase and shifted the cell morphology to a dendritic shape. These effects were inhibited by MTX. Furthermore, PDGF + IL-1β reduced LBH mRNA expression. However, MTX treatment yielded significantly higher transcript levels of LBH, and of CDKN1A (p21) and TP53 (p53), compared to untreated samples upon mitogen stimulation. The expression of DNA methyltransferase-1 (DNMT1) was also higher in the presence of MTX and there was strong correlation between DNMT1 and LBH expression. Conclusions: Therapeutic concentrations of MTX abolish the effects of PDGF and IL-1β on tumor suppressor expression and inhibit mitogen-promoted FLS proliferation. These data demonstrate novel and important effects of MTX on pathogenic effector cells in the joint, which might involve epigenetic mechanisms. © 2018 The Author(s).
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| 40. |
- Bergström, Beatrice, et al.
(författare)
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The Rheumatoid Arthritis Risk Gene AIRE Is Induced by Cytokines in Fibroblast-Like Synoviocytes and Augments the Pro-inflammatory Response
- 2019
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Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- The autoimmune regulator AIRE controls the negative selection of self-reactive T-cells as well as the induction of regulatory T-cells in the thymus by mastering the transcription and presentation of tissue restricted antigens (TRAs) in thymic cells. However, extrathymic AIRE expression of hitherto unknown clinical significance has also been reported. Genetic polymorphisms of AIRE have been associated with rheumatoid arthritis (RA), but no specific disease-mediating mechanism has been identified. Rheumatoid arthritis is characterized by a systemic immune activation and arthritis. Activated fibroblast-like synoviocytes (FLS) are key effector cells, mediating persistent inflammation, and destruction of joints. In this study, we identified AIRE as a cytokine-induced RA risk gene in RA FLS and explored its role in these pathogenic stroma cells. Using RNA interference and RNA sequencing we show that AIRE does not induce TRAs in FLS, but augments the pro-inflammatory response induced by tumor necrosis factor and interleukin-1 beta by promoting the transcription of a set of genes associated with systemic autoimmune disease and annotated as interferon-gamma regulated genes. In particular, AIRE promoted the production and secretion of a set of chemokines, amongst them CXCL10, which have been associated with disease activity in RA. Finally, we demonstrate that AIRE is expressed in podoplanin positive FLS in the lining layer of synovial tissue from RA patients. These findings support a novel pro-inflammatory role of AIRE at peripheral inflammatory sites and provide a potential pathological mechanism for its association with RA.
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| 41. |
- Bergström, Erik, et al.
(författare)
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Is the prevalence of overweight and obesity declining among 4-year-old Swedish children?
- 2009
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Ingår i: Acta Paediatrica. - : John Wiley & Sons. - 0803-5253 .- 1651-2227. ; 98:12, s. 1956-1958
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Tidskriftsartikel (refereegranskat)abstract
- AIM: To investigate the trend in overweight and obesity prevalence among 4-year-old Swedish children. METHODS: Height and weight data registered at the regular health check up at the child health centres in the county of Västerbotten during the years 2007/2008 (2225 boys and 2156 girls) were analysed and compared with data from 2002/2003 (2231 boys and 2176 girls). Overweight and obesity were estimated using the International Obesity Task Force cut-off values (ISO BMI). RESULTS: In both boys and girls, overweight prevalence (ISO BMI > 25) decreased over the 5-year period, boys from 17.2% to 14.2% and girls from 22.3% to 19.0%. Among girls, there was also a decrease in obesity prevalence (ISO BMI > 30) from 5.7% to 3.1%. CONCLUSION: The result of this study indicates that the overweight and obesity epidemic among Swedish pre-school children may be levelling off.
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| 42. |
- Bergström, Göran, 1964, et al.
(författare)
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Low socioeconomic status of a patient's residential area is associated with worse prognosis after acute myocardial infarction in Sweden.
- 2015
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Ingår i: International journal of cardiology. - : Elsevier BV. - 1874-1754 .- 0167-5273. ; 182, s. 141-147
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies have established a relationship between socioeconomic status (SES) and survival in coronary heart disease. Acute cardiac care in Sweden is considered to be excellent and independent of SES. We studied the influence of area-level socioeconomic status on mortality after hospitalization for acute myocardial infarction (AMI) between 1995 and 2013 in the Gothenburg metropolitan area, which has little over 800,000 inhabitants and includes three city hospitals.
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| 43. |
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| 44. |
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| 45. |
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| 46. |
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| 47. |
- Bergström, Hans, et al.
(författare)
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A Study of Valley Winds Using the MIUU Meso-scale Model
- 2006
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Ingår i: Wind Energy. - : Wiley. - 1095-4244 .- 1099-1824. ; 9, s. 109-129
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Tidskriftsartikel (refereegranskat)abstract
- High winds are sometimes found in low-altitude terrain in mountain valleys. The reasons for this and the possibilities to find such sites from modelled wind fields are investigated. The higher-order closure MIUU model developed at Uppsala University is used for a general study of channelling of winds in mountain valleys. The importance of length, width and depth of the valley is investigated. Comparisons are made with wind measurements.
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| 48. |
- Bergström, Hans, et al.
(författare)
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A study of valley winds using the MIUU meso-scale model
- 2004
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Ingår i: 2004 European Wind Energy Conference and Exhibition.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- High winds are sometimes found in low altitude terrain in mountain valleys. The reasons for this and the possibilities to find such sites from modelled wind fields are investigated. The higher-order closure MIUU-model, developed at Uppsala University, is used for a general study of channelling of winds in mountain valleys. The importance of length, width and depth of the valley is investigated. Comparisons are made with wind measurements.
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| 49. |
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| 50. |
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