243 research outputs found
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Life after shock: the mission from Mars to Earth
Extract from introduction: The minerals of the Martian meteorites collected so far indicate an exposure to shock waves in the pressure range of 5 to 55 GPa [1]. As terrestrial rocks are frequently inhabited by microbial communities, rocks ejected from a planet by impact processes may carry with them endolithic microorganisms, if microbial life existed/exists on this planet
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Shock recovery experiments confirm the possibility of transferring viable microorganisms from Mars to Earth
Extract from introduction: With regard to the impact and ejection phase we tested the case for the transfer of microorganisms from Mars to Earth. Using a high explosive set-up thin layers of bacterial endospores of Bacillus subtilis, of the lichen Xanthoria elegans and of the cyanobacterium Chroococcidiopsis sp. embedded between two plates of gabbro were subjected to 10, 20, 30, 40 and 50 GPa which is the pressure range observed in Martian meteorites [1]
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Impact experiments in support of âLithopanspermiaâ: The route from Mars to Earth
Shock recovery experiments on a Martian analogue rock (gabbro) loaded with three types of microorganisms reveal that these organisms survive the impact and ejection phase on Mars at shock pressures up to about 50 GPa with exponentially decreasing survival rates
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The influence of shock pressure, pre-shock temperature, and host rock composition on the survival rate of endolithic microorganisms during impact ejection from Mars
Petrographic and biological analysis of shock recovery experiments confirms the possible life transport due to an impact from Mars to Earth
Variation in Magnetic Fabrics at Low Shock Pressure Due to Experimental Impact Cratering
Magnetic fabrics provide important clues for understanding impact cratering processes. However, only a few magnetic fabric studies for experimentally shocked material have been reported so far. In the framework of MEMIN (Multidisciplinary Experimental and Modeling Impact Research Network), we conducted two impact experiments on blocks of Maggia gneiss with the foliation oriented perpendicular (A38) and parallel (A37) to the target surface. Maggia gneiss has plenty of biotite bands forming a strong rock foliation. The bulk magnetic susceptibility varies from 0.376 Ă 10 to 1.298 Ă 10 SI in unshocked and from 0.443 Ă 10 to 3.940 Ă 10 SI in shocked gneiss. The thermomagnetic curves reveal a Verwey transition at â147 °C and a Curie temperature between 576 and 579 °C in unshocked and shocked samples, indicating nearly pure magnetite, which carries the magnetic fabrics. In A37 and A38 kinking is prominent from the point source down to a depth of 2 and 4.2 d (projectile diameter) or 1 and 2.1 cm, respectively. Kinking, folding, and fracturing changed the position of magnetite grains with respect to each other to reorient the magnetic fabrics. Reorientation of magnetic fabrics is conspicuous down to 20 d (10 cm) in A38, where no other impactârelated deformation is visible. The reorientation of magnetic fabrics may, therefore, aid in identifying impact processes at very low pressures, starting at 0.1 GPa, when other common indicators are absent
The shock compression of microorganism-loaded broths and emulsions: Experiments and simulations
By carefully selecting flyer plate thickness and the geometry of a target capsule for
bacterial broths and emulsions, we have successfully subjected the contents of the capsule to
simultaneous shock and dynamic compression when subjected to a flyer-plate impact
experiment. The capsules were designed to be recovered intact so that post experimental
analysis could be done on the contents. ANSYSÂź AUTODYN hydrocode simulations were
carried out to interrogate the deformation of the cover plate and the wave propagation in the
fluid. Accordingly, we have shown that microorganisms such as Escherichia coli,
Enterococcus faecalis and Zygosaccharomyces bailii are not affected by this type of loading
regime. However, by introducing a cavity behind the broth we were able to observe limited
kill in the yeast sample. Further, on using this latter technique with emulsions it was shown
that greater emulsification of an oil-based emulsion occurred due to the cavitation that was
introduced
Stratigraphic sequence and ages of volcanic units in the Gruithuisen region of the Moon
IMPACT OF A COSMIC BODY INTO EARTH'S OCEAN AND THE GENERATION OF LARGE TSUNAMI WAVES: INSIGHT FROM NUMERICAL MODELING
Virologie / Bakteriologie / Mykologie
141 - Effizienz von Kaliumhypochlorit zur Inaktivierung ausgewĂ€hlter pilzlicher, bakterieller und viraler PflanzenkrankheitserregerEfficancy of Potassium Hypochlorite (KClO) to inactivate selected plant pathogenic fungi, bacteria and virusesMarlon-Hans RodrĂguez, Martina Bandte, Gerhard Fischer, Carmen BĂŒttner142 - Eignung von elektrolytisch generiertem Kaliumhypochlorit zur Inaktivierung von Pflanzenviren in rezirkulierender NĂ€hrlösungen im GewĂ€chshausanbau von TomatenAbility of electrolysed produced Potassium Hypochlorite (KClO) to inactivate plant viruses in recirculating nutrient solutions in greenhouse production of tomatosJanine Paulke, Martina Bandte, Carmen BĂŒttner143 - Ultrafiltration und Ultrazentrifugation zur Konzentrierung von Pflanzenviren in NĂ€hrlösungUltrafiltration and ultracentrifugation as tools to concentrate plant viruses in nutrient solutionJanina Vincenz, Martina Bandte, Carmen BĂŒttner144 - Reinigung doppelstrĂ€ngiger RNA in Verbindung mit Hochdurchsatzsequenzierung als Werkzeug zum Nachweis von RNA Viren in PflanzenThe combination of double-stranded RNA isolation and deep sequencing as an unspecific diagnostic tool to assess the presence of RNA viruses in plantsTill Lesker, Paul Rentz, Edgar Maiss145 - Impact of silica supplementation on virus infected cucumber culturesRolle der KieselsĂ€ureapplikation Virus infizierter GurkenkulturenSabine Holz, Grzegorz Bartoszewski , Michael Kube, Carmen BĂŒttner146 - Untersuchungen zum Auftreten des Arabis mosaic virus in Birken aus Rovaniemi (Finnland) mit Virus-spezifischen SymptomenInvestigations on the occurence of Arabis mosaic virus in birches from Rovaniemi (Finland) with virus-specific symptomsRichard Pauwels, Markus Rott, Susanne von Bargen, Carmen BĂŒttner147 - Cherry leaf roll virus in Betula spp. in Finland: what do we know about its population diversity?Cherry leaf roll virus in Birken-Arten in Finnland: Was wissen wir ĂŒber die PopulationsdiversitĂ€t?A. Rumbou, S. von Bargen, M. Rott, R. Jalkanen, C. BĂŒttner148 - Viruserkrankungen im WeinbauViroses in viticultureHenriette Gruber, Patricia Bohnert, Christiane Rieger149 - Molecular analysis of Tobacco rattle virus isolates from potatoes in various parts of GermanyKerstin Lindner, Renate Koenig150 - Detektion und DiversitĂ€t des European mountain ash ringspot-associated virus (EMARaV) in Ebereschen (Sorbus aucuparia L.) in NorwegenDetection and variability of European mountain ash ringspot-associated virus (EMARaV) in Sorbus aucuparia L. in NorwayTheresa BĂŒttner, Jenny Robel, Hans-Peter MĂŒhlbach, Susanne von Bargen, Carmen BĂŒttner151 - Charakterisierung des European mountain ash ringspot-associated virus (EMARaV) in Mehlbeerenarten (Sorbus spp.)Characterization of the European mountain ash ringspot-associated virus (EMARaV) in whitebeam species (Sorbus spp.)Luisa Dieckmann, Jenny Robel, Susanne von Bargen, Carmen BĂŒttner152 - VollstĂ€ndige Genomsequenz eines Carrot virus S Isolates aus Meerfenchel aus SpanienW. Menzel, P. Menzel, S. Winter153 - Nachweis und vollstĂ€ndige Sequenzierung eines Carla- und eines Potex-virus aus Epiphyullum spec.Detection and complete sequence of a Carla- and Potexvirus in Epiphyllum spec.Edgar Maiss, Paul Rentz, Annette Hohe, Rosa Herbst154 - Analysis of mixed populations of latent viruses of apple and rubbery wood disease of apple using new generation sequencingAnalyse von Mischpopulationen latenter Apfelviren und der Gummiholzkrankheit an Apfel mittels HochdurchsatzsequenzierungVladimir Jakovljevic, Patricia Otten, Jonathon Blake, Wilhelm Jelkmann155 - Experiments on transmission of viroids under glass and longevity of viroid RNA in detached leaves under different storage conditionsThi Thu Vo, Heinz-Wilhelm Dehne, Stephan Winter, Joachim Hamacher156 - Phytoplasmen in Schleswig-HolsteinPhytoplasmas in the state of Schleswig-HolsteinG. Henkel, C. Willmer, M. Wunderlich, B. Golecki157 . Phytoplasmen verĂ€ndern das Dufststoffbouquet ihres pflanzlichen LebensraumsPlant volatile emission is affected by phytoplasma infectionMargit Rid, Kai Lukat, Svenja Hoferer, JĂŒrgen Gross159 - Ist das Wurzelbild ein Sortierungsmerkmal fĂŒr durch Candidatus Phytoplasma pyri verursachten Birnenverfall?Is the root file a sorting feature for Pear decline caused by Canditatus Phytoplama pyri?Georg Henkel, Claudia Willmer, Bernd Kaland, Bettina Golecki160 - Die Bedeutung von ÎČ-Caryophyllen als Lockstoff fĂŒr die Apfeltriebsucht ĂŒbertragende Blattsaugerart Cacopsylla pictaThe impact of ÎČ-caryophyllene as attractant for the Apple Proliferation transmitting insect Cacopsylla pictaConstanze Mesca, Svenja Hoferer, JĂŒrgen Gross161 - Echte Mehltauarten an Beet- und BalkonpflanzenSpecies of powdery mildews on bedding plantsUlrike Brielmaier-Liebetanz162 - Echter Mehltau an Petersilie â Untersuchungen zum WirtspflanzenspektrumPowdery Mildew of Parsley â studies on the host rangePeggy Marx, Ute GĂ€rber163 - Falscher Mehltau an Petersilie â Untersuchungen zum Wirtspflanzenspektrum und molekularbiologische CharakterisierungDowny mildew of parsley â studies on the host range and molecular characterizationGabriele Leinhos, Hermann-Josef Krauthausen, Frank BrĂ€ndle164 - Welkekrankheit an Euonymus japonicaWilt disease on Euonymus japonicaUlrike Brielmaier-Liebetanz, Roswitha Ulrich, Stefan Wagner, Sabine Werres165 - Taxonomische Analyse der mikrobiellen Gemeinschaft von ZuckerrĂŒben unter unterschiedlichen Lagerbedingungen mittels Hochdurchsatz-Amplikonsequenzierung von unterschiedlichen MarkergenenTaxonomic analysis of the microbial community in stored sugar beets using highthroughput sequencing of different marker genesSebastian Liebe, Daniel Wibberg, Anika Winkler, Alfred PĂŒhler, Andreas SchlĂŒter, Mark Varrelmann166 - Molecular characterization of a novel mycovirus found in Rhizoctonia solani AG 2-2IIIBMolekulare Charakterisierung eines neuen Mycovirus aus Rhizoctonia solani AG 2-2 IIIBAnika BartholomĂ€us, Mark Varrelman
Origin and Evolution of Saturn's Ring System
The origin and long-term evolution of Saturn's rings is still an unsolved
problem in modern planetary science. In this chapter we review the current
state of our knowledge on this long-standing question for the main rings (A,
Cassini Division, B, C), the F Ring, and the diffuse rings (E and G). During
the Voyager era, models of evolutionary processes affecting the rings on long
time scales (erosion, viscous spreading, accretion, ballistic transport, etc.)
had suggested that Saturn's rings are not older than 100 My. In addition,
Saturn's large system of diffuse rings has been thought to be the result of
material loss from one or more of Saturn's satellites. In the Cassini era, high
spatial and spectral resolution data have allowed progress to be made on some
of these questions. Discoveries such as the ''propellers'' in the A ring, the
shape of ring-embedded moonlets, the clumps in the F Ring, and Enceladus' plume
provide new constraints on evolutionary processes in Saturn's rings. At the
same time, advances in numerical simulations over the last 20 years have opened
the way to realistic models of the rings's fine scale structure, and progress
in our understanding of the formation of the Solar System provides a
better-defined historical context in which to understand ring formation. All
these elements have important implications for the origin and long-term
evolution of Saturn's rings. They strengthen the idea that Saturn's rings are
very dynamical and rapidly evolving, while new arguments suggest that the rings
could be older than previously believed, provided that they are regularly
renewed. Key evolutionary processes, timescales and possible scenarios for the
rings's origin are reviewed in the light of tComment: Chapter 17 of the book ''Saturn After Cassini-Huygens'' Saturn from
Cassini-Huygens, Dougherty, M.K.; Esposito, L.W.; Krimigis, S.M. (Ed.) (2009)
537-57
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