Institution
University of Vienna
Education•Vienna, Austria•
About: University of Vienna is a education organization based out in Vienna, Austria. It is known for research contribution in the topics: Population & Context (language use). The organization has 44686 authors who have published 95840 publications receiving 2907492 citations.
Topics: Population, Context (language use), Stars, Computer science, Galaxy
Papers published on a yearly basis
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TL;DR: A database analysis of Arabidopsis reveals PP2C to be the largest protein phosphatase family in plants, with 76 members, displaying high complexity, and greatly outnumbering PP2Cs in other eukaryotes.
624 citations
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Institut d'Astrophysique de Paris1, Heidelberg University2, European Southern Observatory3, University College London4, University of St Andrews5, University of Tasmania6, Niels Bohr Institute7, University of Warsaw8, University of Notre Dame9, University of Canterbury10, Space Telescope Science Institute11, Lawrence Livermore National Laboratory12, University of Rijeka13, University of Vienna14, University of Toulouse15, NASA Exoplanet Science Institute16, Osaka University17, University of Concepción18, University of Cambridge19
TL;DR: It is concluded that stars are orbited by planets as a rule, rather than the exception, and that of stars host Jupiter-mass planets 0.5–10 au (Sun–Earth distance) from their stars.
Abstract: Most known extrasolar planets (exoplanets) have been discovered using the radial velocity or transit methods. Both are biased towards planets that are relatively close to their parent stars, and studies find that around 17–30% of solar-like stars host a planet. Gravitational microlensing on the other hand, probes planets that are further away from their stars. Recently, a population of planets that are unbound or very far from their stars was discovered by microlensing. These planets are at least as numerous as the stars in the Milky Way. Here we report a statistical analysis of microlensing data (gathered in 2002–07) that reveals the fraction of bound planets 0.5–10 au (Sun–Earth distance) from their stars. We find that 17^(+16)_(-9)% of stars host Jupiter-mass planets (0.3–10 M_J, where M_J = 318 M_⊕ plus and M_⊕ plus is Earth’s mass). Cool Neptunes (10–30 M_⊕ plus) and super-Earths (5–10 M_⊕ plus) are even more common: their respective abundances per star are 52^(+22)_(-29)% and 62^(+35)_(-73)% . We conclude that stars are orbited by planets as a rule, rather than the exception.
623 citations
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TL;DR: The xenogenic collagen matrix of the Synergraft valve elicits a strong inflammatory response in humans which is non-specific early on and is followed by a lymphocyte response, which may indicate manufacturing problems.
Abstract: Objectives: The first tissue engineered decellularized porcine heart valve, Synergrafte (Cryolife Inc., USA) was introduced in Europe as an alternative to conventional biological valves. This is the first report of the rapid failure of these new grafts in a small series. Materials and methods: In 2001, 2 model 500 and 2 model 700 Synergrafte valves were implanted in four male children (age 2.5‐ 11 years) in the right ventricular outflow tract as a root. Two patients had a Ross operation and two had a homograft replacement. Results: The cryopreserved Synergrafte valves appeared macroscopically unremarkable at implantation. Recovery from surgery was uneventful and good valve function was demonstrated postoperatively. Three children died, two suddenly with severely degenerated Synergrafte valves 6 weeks and 1 year after implantation. The third child died on the 7th day due to Synergrafte rupture. Subsequently the fourth graft was explanted prophylactically 2 days after implantation. Macroscopically all four grafts showed severe inflammation starting on the outside (day 2 explant) leading to structural failure (day 7 explant) and severe degeneration of the leaflets and wall (6 weeks and 1 year explant). Histology demonstrated severe foreign body type reaction dominated by neutrophil granulocytes and macrophages in the early explants and a lymphocytic reaction at 1 year. In addition significant calcific deposits were demonstrated at all stages. Surprisingly pre-implant samples of the Synergrafte revealed incomplete decellularization and calcific deposits. No cell repopulation of the porcine matrix occurred. Conclusion: The xenogenic collagen matrix of the Synergrafte valve elicits a strong inflammatory response in humans which is non-specific early on and is followed by a lymphocyte response. Structural failure or rapid degeneration of the graft occurred within 1 year. Calcific deposits before implantation and incomplete decellularization may indicate manufacturing problems. The porcine Synergrafte treated heart valves should not be implanted at this stage and has been stopped. q 2003 Elsevier Science B.V. All rights reserved.
623 citations
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TL;DR: It is shown that sequences whose ground state structure is thermodynamically well defined show a significant tendency to buffer single point mutations, which can have evolutionary implications, since selection pressure to improve the definition of ground states with biological function may result in increased neutrality.
Abstract: An algorithm is presented for generating rigorously all suboptimal secondary structures between the minimum free energy and an arbitrary upper limit. The algorithm is particularly fast in the vicinity of the minimum free energy. This enables the efficient approximation of statistical quantities, such as the partition function or measures for structural diversity. The density of states at low energies and its associated structures are crucial in assessing from a thermodynamic point of view how well-defined the ground state is. We demonstrate this by exploring the role of base modification in tRNA secondary structures, both at the level of individual sequences from Escherichia coli and by comparing artificially generated ensembles of modified and unmodified sequences with the same tRNA structure. The two major conclusions are that (1) base modification considerably sharpens the definition of the ground state structure by constraining energetically adjacent structures to be similar to the ground state, and (2) sequences whose ground state structure is thermodynamically well defined show a significant tendency to buffer single point mutations. This can have evolutionary implications, since selection pressure to improve the definition of ground states with biological function may result in increased neutrality.
622 citations
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Aristotle University of Thessaloniki1, Centre national de la recherche scientifique2, Wageningen University and Research Centre3, Lund University4, University of Manchester5, Swedish University of Agricultural Sciences6, University of Copenhagen7, University of Giessen8, University of Marburg9, Academy of Sciences of the Czech Republic10, University of Helsinki11, University of Reading12, University of Kent13, University of Vienna14
TL;DR: Intensive agriculture reduces soil biodiversity, making soil food webs less diverse and composed of smaller bodied organisms, and how changes in soil biodiversity due to land-use intensification may threaten the functioning of soil in agricultural production systems is discussed.
Abstract: Soil biodiversity plays a key role in regulating the processes that underpin the delivery of ecosystem goods and services in terrestrial ecosystems. Agricultural intensification is known to change the diversity of individual groups of soil biota, but less is known about how intensification affects biodiversity of the soil food web as a whole, and whether or not these effects may be generalized across regions. We examined biodiversity in soil food webs from grasslands, extensive, and intensive rotations in four agricultural regions across Europe: in Sweden, the UK, the Czech Republic and Greece. Effects of land-use intensity were quantified based on structure and diversity among functional groups in the soil food web, as well as on community-weighted mean body mass of soil fauna. We also elucidate land-use intensity effects on diversity of taxonomic units within taxonomic groups of soil fauna. We found that between regions soil food web diversity measures were variable, but that increasing land-use intensity caused highly consistent responses. In particular, land-use intensification reduced the complexity in the soil food webs, as well as the community-weighted mean body mass of soil fauna. In all regions across Europe, species richness of earthworms, Collembolans, and oribatid mites was negatively affected by increased land-use intensity. The taxonomic distinctness, which is a measure of taxonomic relatedness of species in a community that is independent of species richness, was also reduced by land-use intensification. We conclude that intensive agriculture reduces soil biodiversity, making soil food webs less diverse and composed of smaller bodied organisms. Land-use intensification results in fewer functional groups of soil biota with fewer and taxonomically more closely related species. We discuss how these changes in soil biodiversity due to land-use intensification may threaten the functioning of soil in agricultural production systems.
622 citations
Authors
Showing all 45262 results
Name | H-index | Papers | Citations |
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Tomas Hökfelt | 158 | 1033 | 95979 |
Wolfgang Wagner | 156 | 2342 | 123391 |
Hans Lassmann | 155 | 724 | 79933 |
Stanley J. Korsmeyer | 151 | 316 | 113691 |
Charles B. Nemeroff | 149 | 979 | 90426 |
Martin A. Nowak | 148 | 591 | 94394 |
Barton F. Haynes | 144 | 911 | 79014 |
Yi Yang | 143 | 2456 | 92268 |
Peter Palese | 132 | 526 | 57882 |
Gérald Simonneau | 130 | 587 | 90006 |
Peter M. Elias | 127 | 581 | 49825 |
Erwin F. Wagner | 125 | 375 | 59688 |
Anton Zeilinger | 125 | 631 | 71013 |
Wolfgang Waltenberger | 125 | 854 | 75841 |
Michael Wagner | 124 | 351 | 54251 |