Search

Your search keyword '"Akademie věd České republiky"' showing total 4 results
Start Over Author "Akademie věd České republiky" Language undetermined
4 results on '"Akademie věd České republiky"'

3. Hosts do not simply outsource pathogen resistance to protective symbionts

Author

H. Charles J. Godfray, Ailsa H. C. McLean, Jan Hrcek, Ciara M. Mann, Benjamin J. Parker, Jean-Christophe Simon, University of Oxford [Oxford], University of Rochester [USA], Institut de Génétique, Environnement et Protection des Plantes (IGEPP), AGROCAMPUS OUEST-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Recherche Agronomique (INRA), J.E., Akademie Věd České Republiky, DBI-1306387, Division of Biological Infrastructure, NE/K004972/1, Natural Environment Research Council, Institut de Génétique, Environnement et Protection des Plantes ( IGEPP ), Institut National de la Recherche Agronomique ( INRA ) -Université de Rennes 1 ( UR1 ), Université de Rennes ( UNIV-RENNES ) -Université de Rennes ( UNIV-RENNES ) -AGROCAMPUS OUEST, Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), University of Oxford, and Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST

Subjects
0106 biological sciences, 0301 basic medicine, Pathogen resistance, ecological immunology, robustness, Biology, 010603 evolutionary biology, 01 natural sciences, resistance, 03 medical and health sciences, Symbiosis, Genetics, [ SDV.IB ] Life Sciences [q-bio]/Bioengineering, Natural enemies, Pathogen, Ecology, Evolution, Behavior and Systematics, Aphid, Facultative, fungi, food and beverages, Robustness (evolution), biochemical phenomena, metabolism, and nutrition, 15. Life on land, biology.organism_classification, symbiosis, Acyrthosiphon pisum, 030104 developmental biology, bacteria, [SDV.IB]Life Sciences [q-bio]/Bioengineering, General Agricultural and Biological Sciences
Abstract

International audience; Microbial symbionts commonly protect their hosts from natural enemies, but it is unclear how protective symbionts influence the evolution of host immunity to pathogens. One possibility is that 'extrinsic' protection provided by symbionts allows hosts to reduce investment in 'intrinsic' immunological resistance mechanisms. We tested this idea using pea aphids (Acyrthosiphon pisum) and their facultative bacterial symbionts that increase host resistance to the fungal pathogen Pandora neoaphidis. The pea aphid taxon is composed of multiple host plant associated populations called biotypes, which harbour characteristic communities of symbionts. We found that biotypes that more frequently carry protective symbionts have higher, rather than lower, levels of intrinsic resistance. Within a biotype there was no difference in intrinsic resistance between clones that did and did not carry a protective symbiont. The host plant on which an aphid feeds did not strongly influence intrinsic resistance. We describe a simple conceptual model of the interaction between intrinsic and extrinsic resistance and suggest that our results may be explained by selection favouring both the acquisition of protective symbionts and enhanced intrinsic resistance in habitats with high pathogen pressure. Such combined protection is potentially more robust than intrinsic resistance alone. This article is protected by copyright. All rights reserved.

Published
2018
Full Text
View/download PDF

4. Synthesis and structural/physical properties of U3Fe2Ge7: a single-crystal study

Author

D.I. Gorbunov, António Pereira Gonçalves, Alexander V. Andreev, Mathieu Pasturel, Yurii Skourski, Margarida S. Henriques, Ladislav Havela, João C. Waerenborgh, Michal Dušek, Institute of Physics, Czech Academy of Sciences [Prague] (CAS), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), SFRH/BD/66161/2009, Fundação para a Ciência e a Tecnologia, M10010203, Akademie Věd České Republiky, LM2011025, European Commission, 14-03276S, Grantová Agentura České Republiky, Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Magnetic moment, Condensed matter physics, Magnetic domain, Chemistry, Magnon, Inorganic Chemistry, Magnetic anisotropy, Magnetization, Nuclear magnetic resonance, [CHIM]Chemical Sciences, Orthorhombic crystal system, Physical and Theoretical Chemistry, Anisotropy, Single crystal
Abstract

International audience; A single crystal of U3Fe2Ge7 was synthesized by the tin-flux method, and its structural and electronic properties were studied. The compound crystallizes in the orthorhombic crystal structure of La3Co2Sn7 type with two Wyckoff sites for the U atoms. U3Fe2Ge7 displays a ferromagnetic order below TC = 62 K. Magnetization measurements in static (up to 14 T) and pulsed (up to 60 T) magnetic fields revealed a strong two-ion uniaxial magnetic anisotropy. The easy magnetization direction is along the c axis and the spontaneous magnetic moment is 3.3 μB per formula unit at 2 K. The moment per Fe atom is 0.2 μB, as follows from Mossbauer spectroscopy. The magnetic moments are oriented perpendicular to the shortest inter-uranium distances that occur within the zigzag chains in the ab plane, contrary to other U-based isostructural compounds. The magnetization along the a axis reveals a first-order magnetization process that allows for a quantitative description of the magnetic anisotropy in spite of its enormous energetic strength. The strong anisotropy is reflected in the specific heat and electrical resistivity that are affected by a gap in magnon spectrum.

Published
2015
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results