| 1. |
- Beziat, Vivien, et al.
(författare)
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NK cell responses to cytomegalovirus infection lead to stable imprints in the human KIR repertoire and involve activating KIRs
- 2013
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 121:14, s. 2678-2688
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Tidskriftsartikel (refereegranskat)abstract
- Human natural killer (NK) cells are functionally regulated by killer cell immunoglobulin-like receptors (KIRs) and their interactions with HLA class I molecules. As KIR expression in a given NK cell is genetically hard-wired, we hypothesized that KIR repertoire perturbations reflect expansions of unique NK-cell subsets and may be used to trace adaptation of the NK-cell compartment to virus infections. By determining the human KIR-ome at a single-cell level in more than 200 donors, we were able to analyze the magnitude of NK cell adaptation to virus infections in healthy individuals. Strikingly, infection with human cytomegalovirus (CMV), but not with other common herpesviruses, induced expansion and differentiation of KIR-expressing NK cells, visible as stable imprints in the repertoire. Education by inhibitory KIRs promoted the clonal-like expansion of NK cells, causing a bias for self-specific inhibitory KIRs. Furthermore, our data revealed a unique contribution of activating KIRs (KIR2DS4, KIR2DS2, or KIR3DS1), in addition to NKG2C, in the expansion of human NK cells. These results provide new insight into the diversity of KIR repertoire and its adaptation to virus infection, suggesting a role for both activating and inhibitory KIRs in immunity to CMV infection.
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| 2. |
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| 3. |
- Brunsell, Per R., et al.
(författare)
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Mode Dynamics and Confinement in the Reversed-field Pinch
- 2000
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Ingår i: 18<sup>th</sup> IAEA Fusion Energy Conference in Sorrento, Italy, 4-10 Oct. 2000. Paper IAEA-CN-77/EXP3/14.
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Konferensbidrag (refereegranskat)abstract
- Tearing mode dynamics and toroidal plasma flow in the RFP has been experimentally studied in the Extrap T2 device. A toroidally localised, stationary magnetic field perturbation, the ``slinky mode'' is formed in nearly all discharges. There is a tendency of increased phase alignment of different toroidal Fourier modes, resulting in higher localised mode amplitudes, with higher magnetic fluctuation level. The fluctuation level increases slightly with increasing plasma current and plasma density. The toroidal plasma flow velocity and the ion temperature has been measured with Doppler spectroscopy. Both the toroidal plasma velocity and the ion temperature clearly increase with I/N. Initial, preliminary experimental results obtained very recently after a complete change of the Extrap T2 front-end system (first wall, shell, TF coil), show that an operational window with mode rotation most likely exists in the rebuilt device, in contrast to the earlier case discussed above. A numerical code DEBSP has been developed to simulate the behaviour of RFP confinement in realistic geometry, including essential transport physics. Resulting scaling laws are presented and compared with results from Extrap T2 and other RFP experiments.
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| 4. |
- Brunsell, Per. R., et al.
(författare)
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Resistive wall modes in the EXTRAP T2R reversed-field pinch
- 2003
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Ingår i: Physics of Plasmas. - : AIP Publishing. - 1070-664X .- 1089-7674. ; 10, s. 3823-
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Tidskriftsartikel (refereegranskat)abstract
- Resistive wall modes (RWM) in the reversed field pinch are studied and a detailed comparison of experimental growth rates and linear magnetohydrodynamic (MHD) theory is made. RWM growth rates are experimentally measured in the thin shell device EXTRAP T2R [P. R. Brunsell , Plasma Phys. Controlled Fusion 43, 1 (2001)]. Linear MHD calculations of RWM growth rates are based on experimental equilibria. Experimental and linear MHD RWM growth rate dependency on the equilibrium profiles is investigated experimentally by varying the pinch parameter Theta=B-theta(a)/ in the range Theta=1.5-1.8. Quantitative agreement between experimental and linear MHD growth rates is seen. The dominating RWMs are the internal on-axis modes (having the same helicity as the central equilibrium field). At high Theta, external nonresonant modes are also observed. For internal modes experimental growth rates decrease with Theta while for external modes, growth rates increase with Theta. The effect of RWMs on the reversed-field pinch plasma performance is discussed.
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| 5. |
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| 6. |
- Cecconello, Marco, et al.
(författare)
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Self-organisation and intermittent coherent oscillations in the EXTRAP T2 reversed field pinch
- 2002
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Ingår i: Physica Scripta. - Stockholm : ROYAL SWEDISH ACAD SCIENCES. - 0031-8949 .- 1402-4896. ; 65:1, s. 69-75
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Tidskriftsartikel (refereegranskat)abstract
- Many reversed-field pinch (RFP) experiments exhibit a coherent oscillatory behaviour that is characteristic of discrete dynamo events and is associated with intermittent current profile self-organisation phenomena. However, in the vast majority of the discharges in the resistive shell RFP experiment EXTRAP T2, the dynamo activity does not show global, coherent oscillatory behaviour, The internally resonant tearing modes are phase-aligned and wall-locked resulting in a large localised magnetic perturbation. Equilibrium and plasma parameters have a level of high frequency fluctuations but the average values are quasi-steady. For some discharges, however, the equilibrium parameters exhibit the oscillatory behaviour characteristic of the discrete dynamo events. For these discharges, the trend observed in the tearing mode spectra, associated with the onset of the discrete relaxation event behaviour, is a relative higher amplitude of m = 0 mode activity and relative lower amplitude of the m = 1 mode activity compared with their average values. Global plasma parameters and model profile calculations for sample discharges representing the two types of relaxation dynamics are presented.
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| 7. |
- Cecconello, Marco, et al.
(författare)
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Study of the confinement properties in a reversed-field pinch with mode rotation and gas fuelling
- 2002
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Ingår i: Plasma Physics and Controlled Fusion. - BRISTOL, ENGLAND : IOP PUBLISHING LTD. - 0741-3335 .- 1361-6587. ; 44:8, s. 1625-1638
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Tidskriftsartikel (refereegranskat)abstract
- An extensive investigation of the global confinement properties in different operating scenarios in the rebuilt EXTRAP T2R reversed-field pinch (RFP) experiment is reported here. In particular, the role of a fast gas puff valve system, used to control plasma density, on confinement is studied. Without gas puffing, the electron density decays below 0.5 x 10(19) M-3. The poloidal beta varies between 5% and 15%, decreasing at large I/N. The energy confinement time ranges from 70 to 225 mus. With gas puffing, the density is sustained at n(e) approximate to 1.5 x 10(19) m(-3). However, a general slight deterioration of the plasma performances is observed for the same values of I/N: the plasma becomes cooler and more radiative. The poloidal beta is comparable to that in the scenarios without puff but the energy confinement time drops ranging from 60 to 130 mus. The fluctuation level and the energy confinement time have been found to scale with the Lundquist number as S-0.05+/-0.07 and S0.5+/-0.1, respectively. Mode rotation is typical for all the discharges and rotation velocity is observed to increase with increasing electron diamagnetic velocity.
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| 8. |
- Ek, Mats, et al.
(författare)
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Kompostering av förorenad sand
- 1999
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Till en ren och homogen sand sattes 3-metylbensoesyra, p-kresol, m-xylenol, karbazol och fluoranten, vardera till en halt kring 100 mg/kg fuktig sand. Föreningarna valdes för att de ofta förekommer i mark förorenad med kreosot och petroleumprodukter. Den förorenade sanden ympades med slam från ett kommunalt avloppsreningsverk och fördelades på 10 olika tunnor för komposteringsförsök. Fukthalt (33-59% av fältkapacitet), temperatur (25-35°C) och till-sats av extra substrat och närsalter varierades i ett faktorförsök. Prover togs ut från sanden under nedbrytningsförloppet, och utgående luft från tunnorna analyserades också. Som jämförelse behandlades samma förorenade sand i slurryform, med och utan en inhibitor för biologisk aktivitet. De mest svårlösliga föreningarna, karbazol och fluoranten, blev så ojämnt fördelade i sanden att det inte gick att säga något om deras eventuella nedbrytning. Av de övriga föreningarna avlägsnades i de flesta fall 60-100% under 16 veckors försök. Både hastigheten och sluthalten påverkades av fukthalt och temperatur, däremot hade extra tillsats av substrat och närsalter ingen inverkan. Fukthalt och temperatur påverkade förhållandet mellan avgång till luft och biologisk (kemisk) omvandling. De kemiska analyserna kompletterades med biologiska test med växter och maskar. Den hämmande effekten av den ursprungliga förorenade sanden och ett par behandlade prover var ungefär den som man kunde vänta sig från tidigare försök med rena substanser. I de fall den toxiska effekten var större än den förväntade, kan skillnaden bero på synergistiska effekter eller på toxiska metaboliter
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| 9. |
- Gunnarsson, Carina, et al.
(författare)
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Ullpellets från outnyttjad ull på Gotland – ett utvecklingsprojekt med fokus på pelleteringsprocessen
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Wool pellets from unutilized wool on Gotland – a development project with focus on the pelleting processA large proportion of the wool produced in Sweden is discarded as it cannot be used by the textile industry. Before the wool can be used it must be collected and washed. However, a large quantity of low-quality wool is mixed in with the high-quality wool and thus enter the processing industry when the wool is collected. As it is not usable by the industry, this low-quality wool simply takes up space and lowers the processing speed as it must be separated from the high-quality wool and be discarded, lowering the economic output of the wool processing industry. However, unutilized wool has the potential to be used as a slow-acting fertilizer, soil amendment, or mulch for cultivation purposes. Pelleting is an attractive method of processing biomass into a product that is efficient and easy to handle, transport and use. Pellet presses are commercially available from small farm-scale to large-scale facilities. The aim of the project was to develop and adapt the pelleting technology to work with Swedish wool that cannot be used to produce yarns or other textiles. The goal was to develop methods and technology for pre-treating or disintegrate the wool, adapt the input and pelleting part of the pelleting process to work with low-quality wool and try to optimize the quality of the pellets. Furthermore, the goal was to analyze the plant nutrient value and strength of the pellets produced and create a packaging prototype. During the project, additional goals were added: to automate the process from pre-treatment to packaging as much as possible, and to use literature to determine if the pelletizing process is likely to be sufficient enough to hygenize the wool from weed seeds. An automated production line from wool to finished pellets has been built at Ullkontoret (Sweden’s only full-scale wool washing facility). Coarse and fine shredding, feeding and regulation of feed capacity function well, while the pelleting pressing does not work sufficiently well. Wool pelleting of only low-quality wool proved technologically challenging and neither the modified pellet presses nor the imported wool pellet press worked, despite modifications. In other European countries, this problem is solved by mixing in higher quality wool. Further technological development of wool pelleting is needed to obtain a system that can handle all types of low-quality Swedish wool. Literature studies and nutritional analyses confirm that wool pellets work well as a slow-acting fertilizer (often in mixture due to a very low phosphorus content), but the potential of wool as a soil amendment, mulch and snail repellent requires more studies. Pelleting is probably not enough to hygenize the wool from weed seeds. It is a challenge to produce a packaging that both meets the quality requirements of the product (e.g., maintain the right humidity, preventing odors) and at the same time meets the demands of the type of environmentally conscious consumer who is the main target group for a nature-based product.
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