| 1. |
- Abrahamsson, Marcus, et al.
(författare)
-
Risk- and vulnerability analyses in crisis management of extreme events - A pilot study
- 2004
-
Ingår i: Probabilistic Safety Assessment and Management, vol 1- 6. - 9781852338275 ; , s. 644-649
-
Konferensbidrag (refereegranskat)abstract
- In this paper some findings from a pilot study regarding the use of risk- and vulnerability analysis in society's management of extreme events is presented. The study consisted of two major parts. The first part was an interview study with the main objective to generate a preliminary overview of methods and procedures used by 9 selected Swedish governmental agencies in their risk- and crisis management work. The second part, tightly connected to the interview study, was based on literature studies and generated a more general overview of existing risk- and crisis management strategies, risk- and vulnerability analysis methods etc., covering a wide range of government agency areas/sectors. The pilot study was the "starting point" for a long term research program in this field.
|
|
| 2. |
- Hansen, Jacob B, et al.
(författare)
-
Retinoblastoma protein functions as a molecular switch determining white versus brown adipocyte differentiation.
- 2004
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424. ; 101:12, s. 4112-7
-
Tidskriftsartikel (refereegranskat)abstract
- Adipocyte precursor cells give raise to two major cell populations with different physiological roles: white and brown adipocytes. Here we demonstrate that the retinoblastoma protein (pRB) regulates white vs. brown adipocyte differentiation. Functional inactivation of pRB in wild-type mouse embryo fibroblasts (MEFs) and white preadipocytes by expression of simian virus 40 large T antigen results in the expression of the brown fat-specific uncoupling protein 1 (UCP-1) in the adipose state. Retinoblastoma gene-deficient (Rb-/-) MEFs and stem cells, but not the corresponding wild-type cells, differentiate into adipocytes with a gene expression pattern and mitochondria content resembling brown adipose tissue. pRB-deficient MEFs exhibit an increased expression of the Forkhead transcription factor Foxc2 and its target gene cAMP-dependent protein kinase regulatory subunit RIalpha, resulting in increased cAMP sensitivity. Suppression of cAMP-dependent protein kinase activity in Rb(-/-)MEFs blocked the brown adipocyte-like gene expression pattern without affecting differentiation per se. Immunohistochemical studies revealed that pRB is present in the nuclei of white but not brown adipocyte precursor cells at a developmental stage where both cell types begin to accumulate lipid and brown adipocytes express UCP-1. Furthermore, pRB rapidly undergoes phosphorylation upon cold-induced neodifferentiation and up-regulation of UCP-1 expression in brown adipose tissue. Finally, down-regulation of pRB expression accompanies transdifferentiation of white into brown adipocytes in response to beta3-adrenergic receptor agonist treatment. We propose that pRB acts as a molecular switch determining white vs. brown adipogenesis, suggesting a previously uncharacterized function of this key cell cycle regulator in adipocyte lineage commitment and differentiation.
|
|
| 3. |
- Nylandsted Larsen, A., et al.
(författare)
-
Tin-vacancy acceptor levels in electron-irradiated n-type silicon
- 2000
-
Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 62:7, s. 4535-4544
-
Tidskriftsartikel (refereegranskat)abstract
- Si crystals (n-type, fz) with doping levels between 1.5×1014 and 2×1016 cm-3 containing in addition ∼1018 Sn/cm3 were irradiated with 2-MeV electrons to different doses and subsequently studied by deep level transient spectroscopy, Mössbauer spectroscopy, and positron annihilation. Two tin-vacancy (Sn-V) levels at Ec-0.214 eV and Ec-0.501 eV have been identified (Ec denotes the conduction band edge). Based on investigations of the temperature dependence of the electron-capture cross sections, the electric-field dependence of the electron emissivity, the anneal temperature, and the defect-introduction rate, it is concluded that these levels are the double and single acceptor levels, respectively, of the Sn-V pair. These conclusions are in agreement with electronic structure calculations carried out using a local spin-density functional theory, incorporating pseudopotentials to eliminate the core electrons, and applied to large H-terminated clusters. Thus, the Sn-V pair in Si has five different charge states corresponding to four levels in the band gap.
|
|
