| 1. |
- Clark, Andrew G., et al.
(författare)
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Evolution of genes and genomes on the Drosophila phylogeny
- 2007
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 450:7167, s. 203-218
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Tidskriftsartikel (refereegranskat)abstract
- Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species.
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| 2. |
- Papadopoulos, N G, et al.
(författare)
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Mechanisms of virus-induced asthma exacerbations: state-of-the-art. A GA2LEN and InterAirways document.
- 2007
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Ingår i: Allergy. - : Wiley. - 0105-4538 .- 1398-9995. ; 62:5, s. 457-70
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Forskningsöversikt (refereegranskat)abstract
- Viral infections of the respiratory tract are the most common precipitants of acute asthma exacerbations. Exacerbations are only poorly responsive to current asthma therapies and new approaches to therapy are needed. Viruses, most frequently human rhinoviruses (RV), infect the airway epithelium, generate local and systemic immune responses, as well as neural responses, inducing inflammation and airway hyperresponsiveness. Using in vitro and in vivo experimental models the role of various proinflammatory or anti-inflammatory mediators, antiviral responses and molecular pathways that lead from infection to symptoms has been partly unravelled. In particular, mechanisms of susceptibility to viral infection have been identified and the bronchial epithelium appeared to be a key player. Nevertheless, additional understanding of the integration between the diverse elements of the antiviral response, especially in the context of allergic airway inflammation, as well as the interactions between viral infections and other stimuli that affect airway inflammation and responsiveness may lead to novel strategies in treating and/or preventing asthma exacerbations. This review presents the current knowledge and highlights areas in need of further research.
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| 3. |
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| 4. |
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| 5. |
- von Kockritz-Blickwede, M, et al.
(författare)
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Phagocytosis-independent antimicrobial activity of mast cells by means of extracellular trap formation
- 2008
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 111:6, s. 3070-3080
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Tidskriftsartikel (refereegranskat)abstract
- These days it has been increasingly recognized that mast cells (MCs) are critical components of host defense against pathogens. In this study, we have provided the first evidence that MCs can kill bacteria by entrapping them in extracellular structures similar to the extracellular traps described for neutrophils (NETs). We took advantage of the ability of MCs to kill the human pathogen Streptococcus pyogenes by a phagocytosis-independent mechanism in order to characterize the extracellular antimicrobial activity of MCs. Close contact of bacteria and MCs was required for full antimicrobial activity. Immunofluorescence and electron microscopy revealed that S pyogenes was entrapped by extracellular structures produced by MCs (MCETs), which are composed of DNA, histones, tryptase, and the antimicrobial peptide LL-37. Disruption of MCETs significantly reduced the antimicrobial effect of MCs, suggesting that intact extracellular webs are critical for effective inhibition of bacterial growth. Similar to NETs, production of MCETs was mediated by a reactive oxygen species (ROS)–dependent cell death mechanism accompanied by disruption of the nuclear envelope, which can be induced after stimulation of MCs with phorbol-12-myristate-13-acetate (PMA), H2O2, or bacterial pathogens. Our study provides the first experimental evidence of antimicrobial extracellular traps formation by an immune cell population other than neutrophils.
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| 6. |
- Eriksson, Fredrik, et al.
(författare)
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Atomic scale interface engineering by modulated ion-assisted deposition applied to soft x-ray multilayer optics
- 2008
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Ingår i: Applied Optics. - 1559-128X .- 2155-3165. ; 47:23, s. 4196-4204
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Tidskriftsartikel (refereegranskat)abstract
- Cr/Sc and Ni/V multilayers, intended as normal incidence soft x-ray mirrors and Brewster angle polarizers, have been synthesized by employing a novel modulated low-energy and high-flux ion assistance as a means of engineering the interfaces between the subnanometer layers on an atomic scale during magnetron sputter deposition. To reduce both roughness and intermixing, the ion energy was modulated within each layer. The flat and abrupt interfaces yielded soft x-ray mirrors with near-normal incidence reflectances of R = 20.7% at the Sc 2p absorption edge and R = 2.7% at the V 2p absorption edge. Multilayers optimized for the Brewster angle showed a reflectance of R = 26.7% and an extinction ratio of Rs/Rp=5450 for Cr/Sc and R = 10% and Rs/Rp=4190 for Ni/V. Transmission electron microscopy investigations showed an amorphous Cr/Sc structure with an accumulating high spatial frequency roughness. For Ni/V the initial growth mode is amorphous and then turns crystalline after ~1/3 of the total thickness, with an accumulating low spatial frequency roughness as a consequence. Elastic recoil detection analyses showed that N was the major impurity in both Cr/Sc and Ni/V with concentrations of 15 at. % and 9 at. %, respectively, but also O (3 at. % and 1.3 at. %) and C (0.5 at. % and 1.9 at. %) were present. Simulations of the possible normal incidence reflective properties in the soft x-ray range of 100-600 eV are given, predicting that reflectivities of more than 31% for Cr/Sc and 5.8% for Ni/V can be achieved if better control of the impurities and the deposition process is employed. The simulations also show that Cr/Sc is a good candidate for mirrors for the photon energies between the absorption edges of B (E = 188 eV) and Sc (E = 398.8 eV).
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| 7. |
- Loarer, T., et al.
(författare)
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Gas balance and fuel retention in fusion devices
- 2007
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 0029-5515 .- 1741-4326. ; 47:9, s. 1112-1120
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Tidskriftsartikel (refereegranskat)abstract
- The evaluation of hydrogenic retention in present tokamaks is of crucial importance to estimate the expected tritium (T) vessel inventory in ITER, limited from safety considerations to 350 g. In the framework of the European Task Force on Plasma Wall Interaction (EU TF on PWI) efforts are underway to investigate gas balance and fuel retention during discharges, and to compare the data obtained with those from post-mortem analysis of in-vessel components exposed over whole experimental campaigns. This paper summarizes the principal findings from coordinated studies on gas balance and fuel retention from a number of European tokamaks, namely, ASDEX-Upgrade (AUG), JET, TEXTOR and Tore Supra (TS). For most devices, the long-term retention fraction deduced from integrated particle balance is similar to 10-20%. This is larger than the similar to 3-4% deduced from post-mortem analysis of plasma facing components (PFCs). However, from the database available for tokamaks with their main PFCs made of carbon, the important conclusion is that the T inventory limit (set by the working guideline for operations) could be reached in ITER within fewer than 100 discharges. This, therefore, would seriously impact on operation of the device unless efficient T removal processes are developed.
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| 9. |
- Matussek, A, et al.
(författare)
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Infection of human endothelial cells with Staphylococcus aureus induces transcription of genes encoding an innate immunity response
- 2005
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Ingår i: Scandinavian Journal of Immunology. - : Wiley. - 0300-9475 .- 1365-3083. ; 61:6, s. 536-544
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Tidskriftsartikel (refereegranskat)abstract
- Staphylococcus aureus is a gram-positive bacterium frequently isolated from patients with bloodstream infections. Endothelial cells (EC) play an important role in host defence against bacteria, and recent reports have shown that infection of EC with S. aureus induces expression of cytokines and cell surface receptors involved in activating the innate immune response. The ability of S. aureus to invade nonphagocytic cells, including EC, has been documented. However, the knowledge of the role of EC in pathogenesis of S. aureus infection is still limited. In this study, we investigate the gene-expression program in human EC initiated by internalized 5. aureus, using microarray analysis. We found 156 genes that were differentially regulated at least threefold, using arrays representing 14,239 genes. Many of the up regulated genes code for proteins involved in innate immunity, such as cytokines, chemokines and cell adhesion proteins. Other upregulated genes encode proteins involved in antigen presentation, cell signalling and metabolism. Furthermore, intracellular bacteria survived for days without inducing EC death. © 2005 Blackwell Publishing Ltd.
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| 10. |
- Rohde, Mitchell M., et al.
(författare)
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An Interactive, physics-based unmanned ground vehicle simulator leveraging open source gaming technology : Progress in the development and application of the virtual autonomous navigation environment (VANE) desktop
- 2009
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Ingår i: Unmanned Systems Technology XI. - Bellingham, WA : SPIE - International Society for Optical Engineering. - 9780819475985 ; , s. Article number 73321C-
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Konferensbidrag (refereegranskat)abstract
- It is widely recognized that simulation is pivotal to vehicle development, whether manned or unmanned. There are few dedicated choices, however, for those wishing to perform realistic, end-to-end simulations of unmanned ground vehicles (UGVs). The Virtual Autonomous Navigation Environment (VANE), under development by US Army Engineer Research and Development Center (ERDC), provides such capabilities but utilizes a High Performance Computing (HPC) Computational Testbed (CTB) and is not intended for on-line, real-time performance. A product of the VANE HPC research is a real-time desktop simulation application under development by the authors that provides a portal into the HPC environment as well as interaction with wider-scope semi-automated force simulations (e.g. OneSAF). This VANE desktop application, dubbed the Autonomous Navigation Virtual Environment Laboratory (ANVEL), enables analysis and testing of autonomous vehicle dynamics and terrain/obstacle interaction in real-time with the capability to interact within the HPC constructive geo-environmental CTB for high fidelity sensor evaluations. ANVEL leverages rigorous physics-based vehicle and vehicle-terrain interaction models in conjunction with high-quality, multimedia visualization techniques to form an intuitive, accurate engineering tool. The system provides an adaptable and customizable simulation platform that allows developers a controlled, repeatable testbed for advanced simulations. ANVEL leverages several key technologies not common to traditional engineering simulators, including techniques from the commercial video-game industry. These enable ANVEL to run on inexpensive commercial, off-the-shelf (COTS) hardware. In this paper, the authors d escribe key aspects of ANVEL and its development, as well as several initial applications of the system. © 2009 SPIE.
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