| 1. |
- de Vera, Jean-Pierre, et al.
(författare)
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Limits of Life and the Habitability of Mars : The ESA Space Experiment BIOMEX on the ISS
- 2019
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Ingår i: Astrobiology. - : Mary Ann Liebert. - 1531-1074 .- 1557-8070. ; 19:2, s. 145-157
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- BIOMEX (BIOlogy and Mars EXperiment) is an ESA/Roscosmos space exposure experiment housed within the exposure facility EXPOSE-R2 outside the Zvezda module on the International Space Station (ISS). The design of the multiuser facility supports-among others-the BIOMEX investigations into the stability and level of degradation of space-exposed biosignatures such as pigments, secondary metabolites, and cell surfaces in contact with a terrestrial and Mars analog mineral environment. In parallel, analysis on the viability of the investigated organisms has provided relevant data for evaluation of the habitability of Mars, for the limits of life, and for the likelihood of an interplanetary transfer of life (theory of lithopanspermia). In this project, lichens, archaea, bacteria, cyanobacteria, snow/permafrost algae, meristematic black fungi, and bryophytes from alpine and polar habitats were embedded, grown, and cultured on a mixture of martian and lunar regolith analogs or other terrestrial minerals. The organisms and regolith analogs and terrestrial mineral mixtures were then exposed to space and to simulated Mars-like conditions by way of the EXPOSE-R2 facility. In this special issue, we present the first set of data obtained in reference to our investigation into the habitability of Mars and limits of life. This project was initiated and implemented by the BIOMEX group, an international and interdisciplinary consortium of 30 institutes in 12 countries on 3 continents. Preflight tests for sample selection, results from ground-based simulation experiments, and the space experiments themselves are presented and include a complete overview of the scientific processes required for this space experiment and postflight analysis. The presented BIOMEX concept could be scaled up to future exposure experiments on the Moon and will serve as a pretest in low Earth orbit.
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| 2. |
- Enquist, Henrik, et al.
(författare)
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Subpicosecond hard x-ray streak camera using single-photon counting.
- 2010
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Ingår i: Optics Letters. - 1539-4794. ; 35:19, s. 3219-3221
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Tidskriftsartikel (refereegranskat)abstract
- We have developed and characterized a hard x-ray accumulating streak camera that achieves subpicosecond time resolution by using single-photon counting. A high repetition rate of 2 kHz was achieved by use of a readout camera with built-in image processing capabilities. The effects of sweep jitter were removed by using a UV timing reference. The use of single-photon counting allows the camera to reach a high quantum efficiency by not limiting the divergence of the photoelectrons.
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| 3. |
- Hollestelle, Antoinette, et al.
(författare)
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No clinical utility of KRAS variant rs61764370 for ovarian or breast cancer
- 2016
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Ingår i: Gynecologic Oncology. - : Elsevier BV. - 0090-8258 .- 1095-6859. ; 141:2, s. 386-401
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Tidskriftsartikel (refereegranskat)abstract
- Objective Clinical genetic testing is commercially available for rs61764370, an inherited variant residing in a KRAS 3′ UTR microRNA binding site, based on suggested associations with increased ovarian and breast cancer risk as well as with survival time. However, prior studies, emphasizing particular subgroups, were relatively small. Therefore, we comprehensively evaluated ovarian and breast cancer risks as well as clinical outcome associated with rs61764370. Methods Centralized genotyping and analysis were performed for 140,012 women enrolled in the Ovarian Cancer Association Consortium (15,357 ovarian cancer patients; 30,816 controls), the Breast Cancer Association Consortium (33,530 breast cancer patients; 37,640 controls), and the Consortium of Modifiers of BRCA1 and BRCA2 (14,765 BRCA1 and 7904 BRCA2 mutation carriers). Results We found no association with risk of ovarian cancer (OR = 0.99, 95% CI 0.94-1.04, p = 0.74) or breast cancer (OR = 0.98, 95% CI 0.94-1.01, p = 0.19) and results were consistent among mutation carriers (BRCA1, ovarian cancer HR = 1.09, 95% CI 0.97-1.23, p = 0.14, breast cancer HR = 1.04, 95% CI 0.97-1.12, p = 0.27; BRCA2, ovarian cancer HR = 0.89, 95% CI 0.71-1.13, p = 0.34, breast cancer HR = 1.06, 95% CI 0.94-1.19, p = 0.35). Null results were also obtained for associations with overall survival following ovarian cancer (HR = 0.94, 95% CI 0.83-1.07, p = 0.38), breast cancer (HR = 0.96, 95% CI 0.87-1.06, p = 0.38), and all other previously-reported associations. Conclusions rs61764370 is not associated with risk of ovarian or breast cancer nor with clinical outcome for patients with these cancers. Therefore, genotyping this variant has no clinical utility related to the prediction or management of these cancers.
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| 4. |
- Hultin, Sara, et al.
(författare)
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AmotL2 links VE-cadherin to contractile actin fibres necessary for aortic lumen expansion
- 2014
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- The assembly of individual endothelial cells into multicellular tubes is a complex morphogenetic event in vascular development. Extracellular matrix cues and cell-cell junctional communication are fundamental to tube formation. Together they determine the shape of endothelial cells and the tubular structures that they ultimately form. Little is known regarding how mechanical signals are transmitted between cells to control cell shape changes during morphogenesis. Here we provide evidence that the scaffold protein amotL2 is needed for aortic vessel lumen expansion. Using gene inactivation strategies in zebrafish, mouse and endothelial cell culture systems, we show that amotL2 associates to the VE-cadherin adhesion complex where it couples adherens junctions to contractile actin fibres. Inactivation of amotL2 dissociates VE-cadherin from cytoskeletal tensile forces that affect endothelial cell shape. We propose that the VE-cadherin/amotL2 complex is responsible for transmitting mechanical force between endothelial cells for the coordination of cellular morphogenesis consistent with aortic lumen expansion and function.
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| 5. |
- Laue, Jan, et al.
(författare)
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A soil exploration exercise in Bachelor's level education in soil mechanics
- 2009
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Ingår i: Proceedings of the 17th International Conference on Soil Mechanics and Geotechnical Engineering. - 9781607500315 ; , s. 2752-2755
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Konferensbidrag (refereegranskat)abstract
- Geotechnical education at Bachelor level usually commences with a simplified theoretical introduction into soil mechanics, which may be supported later during the course by hands-on laboratory experiments to cover classification of soils and provide the evidence for the elementary mechanical behaviour of soils. The application of such a curriculum to practice is challenging because the students are not confronted with practical reality where limited information is available to develop a model of the ground. An exercise on site investigation has been developed and incorporated into the ETH Zurich soil mechanics course to help to bridge this gap based on an initial development for undergraduate education in soil mechanics at the University of Sheffield. This exercise, focusing on the three aspects of practical site investigation, creation of a soil model and decision making for best soil condition for a foundation will be introduced and described here. It has been compulsory for the Bachelor students in their first geotechnical course during the first three years after its development. After gaining more experience with the exercise, and under the pressure of growing numbers of students, it has been changed from being compulsory for all students to one of the challenges, from which the students have to select and pass 4 out of 6. Regular evaluation by the students shows that the students appreciate this practical experience and are surprised how little information is often available for practical design tasks. © 2009 IOS Press.
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| 6. |
- Laue, Jan, et al.
(författare)
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Soil structure interaction of circular footings on layered soil : First results
- 2003
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Ingår i: BGA International Conference on Foundations. - 9780727732446 ; , s. 463-472
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Konferensbidrag (refereegranskat)abstract
- A system of granular layers of varying stiffness with weak and consolidated clay layers was investigated. Both numerical and physical modeling were performed in well-specified boundary conditions. Systems containing a single layer of clay embedded between two granular layers of sand were also analyzed. Load-settlement curves of layered soil systems were obtained and a bearing capacity mechanism was applied to the investigations. Compared to a homogeneous granular material, the bearing capacity of a layered soil with a single clay layer between two granular soils decreased with a higher ratio of foundation diameter to layer thickness.
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| 7. |
- Lawrenson, Kate, et al.
(författare)
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Functional mechanisms underlying pleiotropic risk alleles at the 19p13.1 breast-ovarian cancer susceptibility locus
- 2016
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- A locus at 19p13 is associated with breast cancer (BC) and ovarian cancer (OC) risk. Here we analyse 438 SNPs in this region in 46,451 BC and 15,438 OC cases, 15,252 BRCA1 mutation carriers and 73,444 controls and identify 13 candidate causal SNPs associated with serous OC (P=9.2 × 10-20), ER-negative BC (P=1.1 × 10-13), BRCA1-associated BC (P=7.7 × 10-16) and triple negative BC (P-diff=2 × 10-5). Genotype-gene expression associations are identified for candidate target genes ANKLE1 (P=2 × 10-3) and ABHD8 (P<2 × 10-3). Chromosome conformation capture identifies interactions between four candidate SNPs and ABHD8, and luciferase assays indicate six risk alleles increased transactivation of the ADHD8 promoter. Targeted deletion of a region containing risk SNP rs56069439 in a putative enhancer induces ANKLE1 downregulation; and mRNA stability assays indicate functional effects for an ANKLE1 3′-UTR SNP. Altogether, these data suggest that multiple SNPs at 19p13 regulate ABHD8 and perhaps ANKLE1 expression, and indicate common mechanisms underlying breast and ovarian cancer risk.
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| 8. |
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| 9. |
- Springman, Sarah M., et al.
(författare)
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The evolution of a physical modelling course over two decades
- 2014
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Ingår i: Physical Modelling in Geotechnics. - 9781138022218 ; , s. 433-439
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Konferensbidrag (refereegranskat)abstract
- The "Modelling in Geotechnics" course was created in 1996 and was delivered in the final year of diploma studies in civil engineering at ETH Zürich. The principles of modelling were presented and discussed with reference to aspects of physical, constitutive and numerical modeling. This was followed by a series of applications to demonstrate that models can deliver a fast track to developing engineering judgement for promoting optimal geotechnical design, without the concomitant damage that occurs due to real failures, as long as the model is suitable and adheres to the requisite scaling laws. This course is now entitled 'Physical Modelling in Geotechnics' and has seen a significant rise in enrolment. A wide-ranging set of notes was developed at the beginning. These have since been extended, together with an in-house Geotechnical Information Platform GEOTip, which provides the virtual environment for documentation and exchange of ideas. © 2010 Taylor & Francis Group, London.
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