| 1. |
- Pennanen, C, et al.
(författare)
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The effect of apolipoprotein polymorphism on brain in mild cognitive impairment: a voxel-based morphometric study
- 2006
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Ingår i: Dementia and geriatric cognitive disorders. - : S. Karger AG. - 1420-8008 .- 1421-9824. ; 22:1, s. 60-66
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the effect of apolipoprotein E (ApoE) on the whole brain in 51 individuals with mild cognitive impairment using voxel-based morphometry. Between cases heterozygous for the ApoE Ε4 (n = 15) and those who were ApoE Ε4 noncarriers (n = 28), only the right parahippocampal gyrus, with the entorhinal cortex included, reached the level of statistical significance. In cases homozygous for the Ε4 allele (n = 8) versus noncarriers, the greatest atrophy was located in the right amygdala followed by the right parahippocampal gyrus, the left amygdala and the left medial dorsal thalamic nucleus.
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| 2. |
- Santala, M. I. K., et al.
(författare)
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Proton-triton nuclear reaction in ICRF heated plasmas in JET
- 2006
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Ingår i: Plasma Physics and Controlled Fusion. - : IOP Publishing. - 0741-3335 .- 1361-6587. ; 48:8, s. 1233-1253
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Tidskriftsartikel (refereegranskat)abstract
- Fast protons can react with tritons in an endothermic nuclear reaction which can act as a source of neutrons in magnetically confined fusion plasmas. We have performed an experiment to systematically study this reaction in low tritium concentration (approximate to 1%) plasmas in the Joint European Torus. A linear dependence is found between excess neutron rate and tritium concentration when the DT fusion rate is low. We discuss the properties of the neutron emission, including anisotropy, from the proton-triton reaction in a fusion reactor environment and derive simple models for the calculation of the neutron yield from this reaction in terms of tritium density, fast ion temperature and fast ion energy content.
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| 5. |
- Kemp, W. M., et al.
(författare)
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Temporal responses of coastal hypoxia to nutrient loading and physical controls
- 2009
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Ingår i: Biogeosciences. - 1726-4189. ; 6:12, s. 2985-3008
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Forskningsöversikt (refereegranskat)abstract
- The incidence and intensity of hypoxic waters in coastal aquatic ecosystems has been expanding in recent decades coincident with eutrophication of the coastal zone. Worldwide, there is strong interest in reducing the size and duration of hypoxia in coastal waters, because hypoxia causes negative effects for many organisms and ecosystem processes. Although strategies to reduce hypoxia by decreasing nutrient loading are predicated on the assumption that this action would reverse eutrophication, recent analyses of historical data from European and North American coastal systems suggest little evidence for simple linear response trajectories. We review published parallel time-series data on hypoxia and loading rates for inorganic nutrients and labile organic matter to analyze trajectories of oxygen (O-2) response to nutrient loading. We also assess existing knowledge of physical and ecological factors regulating O-2 in coastal marine waters to facilitate analysis of hypoxia responses to reductions in nutrient (and/or organic matter) inputs. Of the 24 systems identified where concurrent time series of loading and O-2 were available, half displayed relatively clear and direct recoveries following remediation. We explored in detail 5 well-studied systems that have exhibited complex, non-linear responses to variations in loading, including apparent 'regime shifts'. A summary of these analyses suggests that O-2 conditions improved rapidly and linearly in systems where remediation focused on organic inputs from sewage treatment plants, which were the primary drivers of hypoxia. In larger more open systems where diffuse nutrient loads are more important in fueling O-2 depletion and where climatic influences are pronounced, responses to remediation tended to follow non-linear trends that may include hysteresis and time-lags. Improved understanding of hypoxia remediation requires that future studies use comparative approaches and consider multiple regulating factors. These analyses should consider: (1) the dominant temporal scales of the hypoxia, (2) the relative contributions of inorganic and organic nutrients, (3) the influence of shifts in climatic and oceanographic processes, and (4) the roles of feedback interactions whereby O-2-sensitive biogeochemistry, trophic interactions, and habitat conditions influence the nutrient and algal dynamics that regulate O-2 levels.
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| 6. |
- Salmi, A., et al.
(författare)
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JET experiments to assess the clamping of the fast ion energy distribution during ICRF heating due to finite Larmor radius effects
- 2006
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Ingår i: Plasma Physics and Controlled Fusion. - : IOP Publishing. - 0741-3335 .- 1361-6587. ; 48:6, s. 717-726
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Tidskriftsartikel (refereegranskat)abstract
- Experiments have been performed on the JET tokamak with 2nd harmonic ion cyclotron resonance heating (ICRH) of hydrogen in deuterium plasmas to assess the role of finite Larmor radius (FLR) effects on the resonant ion distribution function. More specifically, the clamping of high-energy resonant particle distribution due to weak wave-particle interaction at high energy is studied. The distributions of ICRH heated hydrogen ions have been measured with a high-energy neutral particle analyser in the range of 0.29-1.1 MeV. By changing the electron density the energy E*, around which the wave-particle interaction becomes weak, is varied. The dependence of the ion distribution on E* is experimentally observed for a number of discharges and FLR effects are clearly seen to affect the high energy tail shape. Experiments have been analysed with the combination of ICRH modelling codes PION and FIDO, including FLR effects, and good agreement with measurements have been found.
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| 7. |
- Solano, E. R., et al.
(författare)
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ELMS and strike point jumps
- 2005
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Ingår i: Journal of Nuclear Materials. - : Elsevier BV. - 0022-3115 .- 1873-4820. ; 337-39:03-jan, s. 747-750
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Tidskriftsartikel (refereegranskat)abstract
- If an ELM is a peeling of flux surfaces from the plasma, due to a broken separatrix, current density is lost as well as particles and energy. The fast loss of a current-carrying plasma layer modifies the plasma equilibrium, leading to sudden shifts in the strike points at each ELM, towards the plasma centre. An experimental study of this conjectured model of the ELM has been made at JET, showing that in all cases of Type I ELMs studied, strike point shifts were observed. In two cases studied in detail, the estimated equilibrium changes provoked by flux surface peeling agree qualitatively with the observed strike point shifts.
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| 8. |
- Testa, A. C., et al.
(författare)
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Imaging in gynecological disease (1): ultrasound features of metastases in the ovaries differ depending on the origin of the primary tumor
- 2007
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 29:5, s. 505-511
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Tidskriftsartikel (refereegranskat)abstract
- Objective To describe the gray-scale and color Doppler ultrasound findings of metastatic tumors in the ovary according to the origin of the primary tumor. Methods Information was retrieved retrospectively from 67 patients who had undergone preoperative transvaginal gray-scale and color Doppler ultrasound examination and who were found subsequently to have metastatic tumors in their ovaries. In all women the ultrasound information had been collected prospectively using a standardized examination technique and predefined definitions of ultrasound characteristics. Stored ultrasound images were used only to describe retrospectively the external surface of the metastatic tumors. Information on presenting symptoms and on whether the patient had been treated for a malignancy in the past was retrieved retrospectively from patient records. Results Most (95%) ovarian metastases were solid, multilocular-solid or multilocular. Almost all (38/41, 93%) metastases that derived from the stomach, breast, lymphoma or uterus were solid, while most (16/22, 73%) metastases deriving from the colon, rectum, appendix or biliary tract were multilocular or multilocular-solid (P < 0.0001). Metastases that derived from the colon, rectum, appendix or biliary tract were larger compared with those from the stomach, breast, lymphoma or uterus (median maximum diameter, 122 (range, 16-200) mm vs. 71 (range, 27-170) mm, P = 0.02). In addition, irregular external borders were more common (19/22 (86%) vs. 19/41 (46%), P = 0.002), as were papillary projections (6/22 (27%) vs. 2/41 (5%), P = 0.011). They also appeared to be less vascularized, with 64% (14/22) manifesting moderate-to-abundant vascularization at color Doppler examination in comparison to 88% (36/41) of the ovarian metastases from stomach, breast, lymphoma or uterus (P = 0.024). Conclusion Ovarian metastases derived from lymphoma or from tumors in the stomach, breast and uterus are solid in almost all cases, whereas those derived from the colon, rectum or biliary tract manifest more heterogeneous morphological patterns, most being multicystic with irregular borders. Copyright (c) 2007 ISUOG. Published by John Wiley & Sons, Ltd.
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