Swedish Defence Research Agency

About: Swedish Defence Research Agency is a government organization based out in Stockholm, Sweden. It is known for research contribution in the topics: Radar & Synthetic aperture radar. The organization has 1413 authors who have published 2731 publications receiving 56083 citations. The organization is also known as: Totalförsvarets forskningsinstitut.

SNOC: A Monte-Carlo simulation package for high-z supernova observations

Abstract: We present a Monte-Carlo package for simulation of high-redshift supernova data, SNOC. Optical and near-infrared photons from supernovae are ray-traced over cosmological distances from the simulated host galaxy to the observer at Earth. The distances to the sources are calculated from user provided cosmological parameters in a Friedmann-Lemaˆ itre universe, allowing for arbitrary forms of "dark energy". The code takes into account gravitational interactions (lensing) and extinction by dust, both in the host galaxy and in the line-of-sight. The user can also choose to include exotic eects like a hypothetical attenuation due to photon-axion oscillations. SNOC is primarily useful for estimations of cosmological parameter uncertainties from studies of apparent brightness of type Ia supernovae vs redshift, with special emphasis on potential systematic eects. It can also be used to compute standard cosmological quantities like luminosity distance, lookback time and age of the universe in any Friedmann-Lemaˆ itre model with or without quintessence.

The phylogeographic pattern of Francisella tularensis in Sweden indicates a Scandinavian origin of Eurosiberian tularaemia

Abstract: Previous studies of the causative agent of tularaemia, Francisella tularensis have identified phylogeographic patterns suggestive of environmental maintenance reservoirs. To investigate the phyloge ...

Treatment with dexamethasone or liposome-encapsuled vitamin E provides beneficial effects after chemical-induced lung injury.

Abstract: The pathogenesis of lung injury by exposure to highly toxic sulfur and nitrogen mustards involves alkylating damage of the respiratory epithelium followed by an acute inflammatory response and lung edema. The acute phase is followed by long-term respiratory complications characterized by bronchitis, lung fibrosis, and airway hyperreactivity. In this study, we utilized a mouse model for airway inflammation induced by inhalation exposure to the alkylating nitrogen mustard melphalan, in order to investigate possible beneficial treatment effects by the corticosteroid dexamethasone. In addition, we investigated therapeutic efficacy of liposome-encapsuled vitamin E, an antioxidant formulation previously shown to be efficient in counteracting inflammatory conditions. Influx of inflammatory cells to airways, edema formation, and expression of different cytokines were analyzed 6 and 18 hours after exposure to melphalan. In order to evaluate long-term lung effects, we also investigated collagen deposition and accumulation of lymphocytes at 2 and 4 weeks after exposure. A single intraperitoneal injection of dexamethasone (10 mg/kg body weight) 1 hour after melphalan exposure significantly reduced interleukin (IL)-1 and IL-6 in bronchoalveolar lavage fluid (BALF) and diminished the acute airway inflammation. Our results also indicate that early single-dose treatment with dexamethasone protects against long-term effects observed 2-4 weeks after melphalan exposure, as indicated by reduced lymphocytic response in airways and decreased collagen deposition. Furthermore, our results indicate that also vitamin E (50 mg/kg) reduces acute inflammatory cell influx, and suppresses collagen formation in lung tissue, indicating that this drug could be used in combination with corticosteroids for protection against chemical-induced lung injury.

Genome Sequencing Shows that European Isolates of Francisella tularensis Subspecies tularensis Are Almost Identical to US Laboratory Strain Schu S4

Abstract: Background Francisella tularensis causes tularaemia, a life-threatening zoonosis, and has potential as a biowarfare agent. F. tularensis subsp. tularensis, which causes the most severe form of tularaemia, is usually confined to North America. However, a handful of isolates from this subspecies was obtained in the 1980s from ticks and mites from Slovakia and Austria. Our aim was to uncover the origins of these enigmatic European isolates. Methodology/Principal Findings We determined the complete genome sequence of FSC198, a European isolate of F. tularensis subsp. tularensis, by whole-genome shotgun sequencing and compared it to that of the North American laboratory strain Schu S4. Apparent differences between the two genomes were resolved by re-sequencing discrepant loci in both strains. We found that the genome of FSC198 is almost identical to that of Schu S4, with only eight SNPs and three VNTR differences between the two sequences. Sequencing of these loci in two other European isolates of F. tularensis subsp. tularensis confirmed that all three European isolates are also closely related to, but distinct from Schu S4. Conclusions/Significance The data presented here suggest that the Schu S4 laboratory strain is the most likely source of the European isolates of F. tularensis subsp. tularensis and indicate that anthropogenic activities, such as movement of strains or animal vectors, account for the presence of these isolates in Europe. Given the highly pathogenic nature of this subspecies, the possibility that it has become established wild in the heartland of Europe carries significant public health implications.

Limits to the muon flux from WIMP annihilation in the center of the Earth with the AMANDA detector

Abstract: A search for nearly vertical up-going muon-neutrinos from neutralino annihilations in the center of the Earth has been performed with the AMANDA-B10 neutrino detector. The data collected in 130.1 days of live time in 1997, ∼10 9 events, have been analyzed for this search. No excess over the expected atmospheric neutrino background has been observed. An upper limit at 90% confidence level has been obtained on the annihilation rate of neutralinos in the center of the Earth, as well as the corresponding muon flux limit, both as a function of the neutralino mass in the range 100 GeV-5000 GeV. © 2002 The American Physical Society.