| 1. |
- Joyce, J.J., et al.
(författare)
-
Photoemission and the electronic structure of PuGaCo$_5$
- 2003
-
Ingår i: Physical Review Letters. ; 91, s. 176401-
-
Tidskriftsartikel (refereegranskat)abstract
- The electronic structure of the first Pu-based superconductor PuCoGa5 is explored using photoelectron spectroscopy and a novel theoretical scheme. Exceptional agreement between calculation and experiment defines a path forward for understanding the electronic structure aspects of Pu-based materials. The photoemission results show two separate regions of 5f electron spectral intensity, one at the Fermi energy and another centered 1.2 eV below the Fermi level. The results for PuCoGa5 clearly indicate 5f electron behavior on the threshold between localized and itinerant. Comparisons to delta phase Pu metal show a broader framework for understanding the fundamental electronic properties of the Pu 5f levels in general within two configurations, one localized and one itinerant.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Mantsinen, M. J., et al.
(författare)
-
Analysis of ion cyclotron heating and current drive at omega approximate to 2 omega(cH) for sawtooth control in JET plasmas
- 2002
-
Ingår i: Plasma Physics and Controlled Fusion. - : IOP Publishing. - 0741-3335 .- 1361-6587. ; 44:8, s. 1521-1542
-
Tidskriftsartikel (refereegranskat)abstract
- Ion cyclotron heating and current drive at omega approximate to 2omega(cH) in JET deuterium plasmas with a hydrogen concentration n(H)/(n(D)+n(H)) in the range of 5-15% are analysed, comparing results of numerical computer modelling with experiments. Second harmonic hydrogen damping is found to be maximized by placing the resonance on the, low-field side (LFS) of the torus, which minimizes competing direct electron damping and parasitic high-harmonic D damping in the presence of D beams. The shape of the calculated current perturbation and the radial localization of the heating power density for the LFS resonance are consistent with the experimentally observed evolution of the sawtooth period when the resonance layer moves near the q = 1 surface. Since the calculated driven current is dominated by a current of diamagnetic type caused by finite orbit widths of trapped resonating ions, it is not too sensitive to the ICRF phasing. Control of sawteeth with ion cyclotron current drive using the LFS omega approximate to 2omega(cH) resonance in the present experimental conditions can thus be best obtained by varying the resonance location rather than the ICRF phasing. Due to differences in fast ion orbits, collisional electron heating and fast ion pressure profiles are significantly more peaked for a LFS resonance than for a high-field side (HFS) resonance. For the HFS omega approximate to 2omega(cH) resonance, an enhanced neutron rate is observed in the presence of D beam ions, which is consistent with parasitic D damping at the omega approximate to 2omega(cD) resonance in the plasma centre.
|
|
| 5. |
- Törn, Carina, et al.
(författare)
-
Combinations of beta cell specific autoantibodies at diagnosis of diabetes in young adults reflects different courses of beta cell damage
- 2001
-
Ingår i: Autoimmunity. - 0891-6934. ; 33:2, s. 115-120
-
Tidskriftsartikel (refereegranskat)abstract
- To explore the natural course of beta cell function in recent onset diabetes, a subgroup (n = 157) of all incident cases (n = 879) 15-34 years old. 1992-1993 in Sweden. and with positivity for at least one autoantibody of islet cell antibodies (ICA), glutamic acid decarboxylase antibodies (GADA) or tyrosine phosphatase antibodies (1A-2A) were followed prospectively thr the first four years with annual analysis of C-peptide. The aim was to relate the course of beta cell function, measured as C-peptide, in early diabetes with the presence of different islet autoantibodies at diagnosis. We found that patients positive for ICA alone (n = 11 ) had significantly higher C-peptide levels both at diagnosis and during the first three years compared with the other patients (n = 146; p = 0.022, p < 0.001, p = 0.004 and p = 0.0022). Patients positive for GADA alone or in combination with other antibodies (n = 125) had significantly lower C-peptide during the first three years after diagnosis compared with the other patients (n = 32. p < 0.001, p = 0.0011 and p = 0.0136). Patients with two or three autoantibodies had C-peptide levels similar to levels found in patients positive only for GADA. However. after four years, there were no significant differences between any of the groups of different autoantibody combinations. At diagnosis. 55% (86/157) of the patients had C-peptide: levels above the lower normal range of 0.25 nmol/l, but the frequency of patients with beta cell Function above this level decreased after two years to 41% (65/157; p = 0.035) and after four years to 22% (35/157; p = 0.0041).
|
|
| 6. |
- Boström, R., Eriksson, A.I., Åhlén, L., Blomberg, L., Gustafsson, G., Holback, B., Holmgren, G., Holtet, J., Jansson, S.E., Lindqvist, P.A., Lybekk, B., Mälkki, A., Riihelä, P. and Wahlund, J.E.
(författare)
-
The Rosetta Dual Langmuir Probe Instrument for Measurements of Plasma Density, Temperature and Flow Velocity.
- 2001
-
Ingår i: ESA SP-1165.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)
|
|
| 7. |
|
|
| 8. |
- Carlsson, J, et al.
(författare)
-
Kin-biased distribution in brown trout : an effect of redd location or kin recognition?
- 2004
-
Ingår i: Heredity. - : Springer Science and Business Media LLC. - 0018-067X .- 1365-2540. ; 92:2, s. 53-60
-
Tidskriftsartikel (refereegranskat)abstract
- A wide range of animals have been reported to show kin-biased behaviours, such as reduced aggressiveness and increased food sharing among relatives. However, less is known about whether wild animals also associate with relatives under natural conditions, which is a prerequisite to facilitate kin-biased behaviours and hence kin selection. We tested, by means of microsatellite polymorphism, correlations between pair-wise relatedness and pair-wise metric distance in wild brown trout ( Salmo trutta L.) under natural conditions in two streams. Our data show that young-of-the-year as well as older trout found close together also had a higher genetic relatedness in one of the two streams, whereas no relationship was found in the other stream. Very few half and full siblings were found in the second stream and under these conditions it is unlikely that kin-biased behaviours will receive positive selection. We discuss the underlying mechanisms for the observed structure and we specifically address the issue of whether the grouping of related individuals could reflect dispersal from the same spawning redds, or if it reflects active association with relatives, possibly conferring kin-selected advantages.
|
|
| 9. |
|
|
| 10. |
- Cunningham, J L, et al.
(författare)
-
Transmembrane protein tyrosine phosphatase IA-2 (ICA512) is expressed in human midgut carcinoids but is not detectable in normal enterochromaffin cells.
- 2000
-
Ingår i: Journal of Endocrinology. - 0022-0795 .- 1479-6805. ; 164:3
-
Tidskriftsartikel (refereegranskat)abstract
- A potential upregulation of receptor type protein tyrosine phosphatase IA-2 (ICA512) expression was detected by differential display and investigated in midgut carcinoid tumours. Normal intestine tissue and tumour tissue from 13 midgut carcinoid patients were studied by in situ hybridisation using an IA-2 ribonucleotide probe and confocal microscopy using specific IA-2 antibodies. Previously, it had been shown that IA-2 is located in the secretory granules of virtually all neuroendocrine cells. However, we found that IA-2 was not detectable in resting normal enterochromaffin (EC) cells of the small intestine, while high expression of IA-2 mRNA and protein was confirmed in both primary and metastatic carcinoid tissue. This difference in expression was not observed with chromogranin A or serotonin, two secretory granule hormones known to be expressed in EC cells, indicating that IA-2 was seemingly not necessary for the basal production and packaging of these hormones. When comparing patients receiving biotherapy before operation with untreated patients, we found expression of IA-2 to be lower in tumours from patients that had been treated with a combination of alpha-interferon and the somatostatin analogue, octreotide. There was no correlation between IA-2 expression and proliferation rates as measured by immunohistochemistry with antibodies against the Ki 67 antigen. Furthermore, we show that IA-2 is co-localised with serotonin in carcinoid tumours as well as in the pancreatic tumour cell line, BON1, which is interesting as serotonin secretion rate is presumably higher in tumour cells than in resting EC cells. Taken together, these findings may indicate a role for IA-2 in the later stages of the regulated secretory process.
|
|
