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Institution

Swedish Defence Research Agency

GovernmentStockholm, Sweden
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.


Papers
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Journal ArticleDOI
TL;DR: Results, obtained at the proteome level, support and confirm recently published data showing that the igl operon genes are transcribed in response to iron limitation, and help clarify the virulence mechanisms of F. tularensis.
Abstract: Francisella tularensis is a highly virulent, facultative intracellular pathogen that causes tularemia in humans and animals. Although it is one of the most infectious bacterial pathogens, little is known about its virulence mechanisms. In this study, the response of F. tularensis live vaccine strain to iron depletion, which simulates the environment within the host, was investigated. In order to detect alterations in protein synthesis, metabolic labeling, followed by 2D-PAGE analysis was used. Globally, 141 protein spots were detected whose levels were significantly altered in the iron-restricted medium. About 65% of the spots were successfully identified using mass spectrometric approaches. Importantly, among the proteins produced at an increased level during iron-limited growth, three proteins were found encoded by the igl operon, located in the F. tularensis pathogenicity island I (FPI). Of these, the IglC and IglA proteins were previously reported to be necessary for full virulence of F. tularensis. These results, obtained at the proteome level, support and confirm recently published data showing that the igl operon genes are transcribed in response to iron limitation.

53 citations

Journal ArticleDOI
TL;DR: In this paper, a method using gradient-based optimization is introduced for the design of wing profiles with the aim of natural laminar flow, as well as minimum wave drag.
Abstract: A method using gradient-based optimization is introduced for the design of wing profiles with the aim of natural laminar flow, as well as minimum wave drag. The Euler equations of gasdynamics, the laminar boundary-layer equations for compressible flows on infinite swept wings, and the linear parabolized stability equations (PSE) are solved to analyze the evolution of convectively unstable disturbances. Laminar‐turbulent transition is assumed to be delayed by minimizing a measure of the disturbance kinetic energy of a chosen disturbance, which is computed using the PSE. The shape gradients of the disturbance kinetic energy are computed based on the solutions of the adjoints of the state equations just named. Numerical tests are carried out to optimize the RAE 2822 airfoil with the aim to delay simultaneously the transition, reduce the pressure drag coefficient, and maintain the coefficients of lift and pitch moments. Constraints are also applied on the geometry. Results show a reduction of the total amplification of a large number of disturbances, which is assumed to represent a delay of the transition in the boundary layer. Because delay of the transition implies reduction of the viscous drag, the present method enables shape optimization to perform viscous drag reduction.

53 citations

Journal ArticleDOI
TL;DR: It is shown that the weak implementation is superior and enhances the convergence to steady-state for coarse meshes, and it is demonstrated that all the stable approaches produce the same convergence rate as the mesh size goes to zero.

53 citations

Journal ArticleDOI
TL;DR: In this paper, the authors investigated whether mosquitoes acquire the bacterium as aquatic larvae and transmit the disease as adults in a Swedish area where tularaemia is endemic (Orebro) and found that F. tularensis subsp. holarctica was transmitted to 58% of the adult mosquitoes feeding on diseased mice.
Abstract: In Sweden, mosquitoes are considered the major vectors of the bacterium Francisella tularensis subsp. holarctica, which causes tularaemia. The aim of this study was to investigate whether mosquitoes acquire the bacterium as aquatic larvae and transmit the disease as adults. Mosquitoes sampled in a Swedish area where tularaemia is endemic (Orebro) were positive for the presence of F. tularensis deoxyribonucleic acid throughout the summer. Presence of the clinically relevant F. tularensis subsp. holarctica was confirmed in 11 out of the 14 mosquito species sampled. Experiments performed using laboratory-reared Aedes aegypti confirmed that F. tularensis subsp. holarctica was transstadially maintained from orally infected larvae to adult mosquitoes and that 25 % of the adults exposed as larvae were positive for the presence of F. tularensis-specific sequences for at least 2 weeks. In addition, we found that F. tularensis subsp. holarctica was transmitted to 58 % of the adult mosquitoes feeding on diseased mice. In a small-scale in vivo transmission experiment with F. tularensis subsp. holarctica-positive adult mosquitoes and susceptible mice, none of the animals developed tularaemia. However, we confirmed that there was transmission of the bacterium to blood vials by mosquitoes that had been exposed to the bacterium in the larval stage. Taken together, these results provide evidence that mosquitoes play a role in disease transmission in part of Sweden where tularaemia recurs.

53 citations

Journal ArticleDOI
TL;DR: In this article, the authors investigated mental workload in basic civil aviation training and found that the increase of workload starts in advance of an unexpected event in the simulator where it seems to be of a preparatory nature, whereas in the aircraft it is more connected to management of the situation.
Abstract: This study investigated mental workload in basic civil aviation training. Heart rate, eye movement, and subjective ratings from 11 students were collected during simulator and aircraft sessions. Results show high correspondence in psychophysiological reactions between the sessions. For some flight segments, heart rate was consistently lower in the simulator, suggesting higher mental workload in the aircraft. Differences in heart rate during rejected takeoff and engine failure indicate that the increase of workload starts in advance of an “unexpected” event in the simulator where it seems to be of preparatory nature, whereas in the aircraft it is more connected to management of the situation.

53 citations


Authors

Showing all 1417 results

NameH-indexPapersCitations
Anders Larsson80130733995
Anders Johansson7553821709
Anders Eriksson6867919487
Dan S. Henningson6636919038
Bengt Johansson6663519206
Anders Sjöstedt6319611422
Björn Johansson6263716030
Mats Gustafsson6152018574
D. G. Joakim Larsson5815113687
Anders Larsson5419855761
Mats Tysklind5325017534
Jerker Fick511438787
Erik Johansson501149437
Göran Finnveden4919312663
Ian A. Nicholls451947522
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
20232
20228
202163
202074
2019102
201894