181 research outputs found

    Getreidearten und UngrÀser als alternative Wirtspflanzen der Larven von Diabrotica virgifera virgifera LeConte, 1868 (Coleoptera, Chrysomelidae)

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    Schon Ende der 60er Jahre fanden in den USA Untersuchungen zum Wirtsspektrum der Larven des Westlichen Maiswurzelbohrers (Diabrotica virgifera virgifera LECONTE (Coleoptera, Chrysomelidae)) statt (BRANSON & ORTMAN 1967 & 1970). Dort wurden annĂ€hernd zwanzig ausschließlich monocotyledone Wirtspflanzen fĂŒr Larven des Maiswurzelbohrers festgestellt. Dicotyledone Pflanzen scheinen als Wirtspflanzen dagegen nicht geeignet zu sein. Trotz der Bedeutung des Themas besonders im Hinblick auf die Fruchtfolge als IPM-Maßnahme fand dies bisher nur wenig Beachtung. Allerdings gewinnt dieses Thema im Zusammenhang mit der EU-Entscheidung zur Eradikation und EindĂ€mmung des KĂ€fers zusĂ€tzliches Interesse.Since the late 60s it is known that larvae of the Western Corn Rootworm (Diabrotica virgifera virgifera LECONTE 1868 (Coleoptera, Chrysomelidae)) do not only feed on maize. BRANSON & ORTMAN (1967 & 1970) recorded nearly twenty possible monocotyledonous host plants for the larvae of D. virgifera virgifera in the USA. For this reason we determined the suitability of different cereals and monocotyledonous weeds as hosts for larvae of D. virgifera virgifera which may be suitable in Europe. We determined 7 suitable plant species for the larvae out of 13 tested. The results need to be confirmed in field trials which have been initiated

    Biomolecules / Oxidative stress in fungi : its function in signal transduction, interaction with plant hosts, and lignocellulose degradation

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    In this review article, we want to present an overview of oxidative stress in fungal cells in relation to signal transduction, interaction of fungi with plant hosts, and lignocellulose degradation. We will discuss external oxidative stress which may occur through the interaction with other microorganisms or plant hosts as well as internally generated oxidative stress, which can for instance originate from NADPH oxidases or “leaky” mitochondria and may be modulated by the peroxiredoxin system or by protein disulfide isomerases thus contributing to redox signaling. Analyzing redox signaling in fungi with the tools of molecular genetics is presently only in its beginning. However, it is already clear that redox signaling in fungal cells often is linked to cell differentiation (like the formation of perithecia), virulence (in plant pathogens), hyphal growth and the successful passage through the stationary phase.(VLID)157469

    Speleothems Reveal 500,000-year History of Siberian Permafrost

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    Soils in permafrost regions contain twice as much carbon as the atmosphere, and permafrost has an important influence on the natural and built environment at high northern latitudes. The response of permafrost to warming climate is uncertain and occurs on time scales longer than those assessed by direct observation. We dated periods of speleothem growth in a north-south transect of caves in Siberia to reconstruct the history of permafrost in past climate states. Speleothem growth is restricted to full interglacial conditions in all studied caves. In the northernmost cave (at 60°N), no growth has occurred since Marine Isotopic Stage (MIS) 11. Growth at that time indicates that global climates only slightly warmer than today are sufficient to thaw extensive regions of permafrost

    See-saw relationship of the Holocene East Asian-Australian summer monsoon

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    D.E. and N.M. acknowledge support by the Leibniz Association (WGL) under Grant No. SAW-2013-IZW-2. F.H.M.’s research is funded through an Australian Postgraduate Award. I.O. is financially supported from TUBITAK under 2214/A program and by Ege University under the Research Project number 2015FEN028. This study received funding from the European Union’s Horizon 2020 Research and Innovation programme under the Marie SkƂodowska-Curie grant agreement No 691037. The publication of this article was funded by the Open Access Fund of the Leibniz Association. K.H.W. thank Rhawn F. Denniston for his wider involvement in the northwest Australian monsoon project and the Kimberley Foundation Australia for financial support for this project and Paul Wyrwoll for helpful comments. We are also grateful to Yanjun Cai for providing the Lake Qinghai record.Peer reviewedPublisher PD

    Defining paleoclimatic routes and opportunities for hominin dispersals across Iran

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    Fossil and archaeological evidence indicates that hominin dispersals into Southwest Asia occurred throughout the Pleistocene, including the expansion of Homo sapiens populations out of Africa. While there is evidence for hominin occupations in the Pleistocene in Iran, as evidenced by the presence of Lower to Upper Paleolithic archaeological sites, the extent to which humid periods facilitated population expansions into western Asia has remained unclear. To test the role of humid periods on hominin dispersals here we assess Paleolithic site distributions and paleoenvironmental records across Iran. We developed the first spatially comprehensive, high-resolution paleohydrological model for Iran in order to assess water availability and its influence on hominin dispersals. We highlight environmentally mediated routes which likely played a key role in Late Pleistocene hominin dispersals, including the expansion of H. sapiens and Neanderthals eastwards into Asia. Our combined analyses indicate that, during MIS 5, there were opportunities for hominins to traverse a northern route through the Alborz and Kopet Dagh Mountains and the Dasht-I Kavir desert owing to the presence of activated fresh water sources. We recognize a new southern route along the Zagros Mountains and extending eastwards towards Pakistan and Afghanistan. We find evidence for a potential northern route during MIS 3, which would have permitted hominin movements and species interactions in Southwest Asia. Between humid periods, these interconnections would have waned, isolating populations in the Zagros and Alborz Mountains, where hominins may have continued to have had access to water

    Persistent drying in the tropics linked to natural forcing.

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    Approximately half of the world's population lives in the tropics, and future changes in the hydrological cycle will impact not just the freshwater supplies but also energy production in areas dependent upon hydroelectric power. It is vital that we understand the mechanisms/processes that affect tropical precipitation and the eventual surface hydrological response to better assess projected future regional precipitation trends and variability. Paleo-climate proxies are well suited for this purpose as they provide long time series that pre-date and complement the present, often short instrumental observations. Here we present paleo-precipitation data from a speleothem located in Mesoamerica that reveal large multi-decadal declines in regional precipitation, whose onset coincides with clusters of large volcanic eruptions during the nineteenth and twentieth centuries. This reconstruction provides new independent evidence of long-lasting volcanic effects on climate and elucidates key aspects of the causal chain of physical processes determining the tropical climate response to global radiative forcing.A.W. thanks the Swiss Federal Institute of Technology both for hosting his sabbatical and for the analysis of the stable isotopes. A.W. also thanks Cluster of Excellence CliSAP at the University of Hamburg for sponsoring collaboration. Collection of GU-Xi-1 by T.M. was supported through a sabbatical granted by the University of Puerto Rico (Mayagu¹ez) and the National Geographic Society Grant no. 3089-85 to T.M. partially supported survey of the cave and location of the stalagmite. The research was supported in part by the National Science Foundation ATM-1003502. Y.K. was also supported by grant NA10OAR4310137 from the National Oceanic and Atmospheric Administration— Climate Program Office. S.F.M.B. acknowledges financial support from the Schweizer National Fond Project CRS122 132646/1. D.B. was supported by National Science Foundation Grant ATM-1003219. G.L. acknowledges support from Helmholtz through PACES and REKLIM. We acknowledge the World Climate Research Program Working Group on Coupled Modeling, which is responsible for CMIP, and we thank the climate modelling groups for producing and making available their model output. Paul Sammarco (LUMCON) is thanked for some advice regarding statistical and data interpretation. This paper is a Lamont Doherty Contribution number 7901. LB was supported by the French National Research Agency under EL PASO grant 10-Blan-608-01.This is the accepted manuscript. The final version is available at http://www.nature.com/ncomms/2015/150714/ncomms8627/full/ncomms8627.html

    Software JimenaE allows efficient dynamic simulations of Boolean networks, centrality and system state analysis

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    The signal modelling framework JimenaE simulates dynamically Boolean networks. In contrast to SQUAD, there is systematic and not just heuristic calculation of all system states. These specific features are not present in CellNetAnalyzer and BoolNet. JimenaE is an expert extension of Jimena, with new optimized code, network conversion into different formats, rapid convergence both for system state calculation as well as for all three network centralities. It allows higher accuracy in determining network states and allows to dissect networks and identification of network control type and amount for each protein with high accuracy. Biological examples demonstrate this: (i) High plasticity of mesenchymal stromal cells for differentiation into chondrocytes, osteoblasts and adipocytes and differentiation-specific network control focusses on wnt-, TGF-beta and PPAR-gamma signaling. JimenaE allows to study individual proteins, removal or adding interactions (or autocrine loops) and accurately quantifies effects as well as number of system states. (ii) Dynamical modelling of cell–cell interactions of plant Arapidopsis thaliana against Pseudomonas syringae DC3000: We analyze for the first time the pathogen perspective and its interaction with the host. We next provide a detailed analysis on how plant hormonal regulation stimulates specific proteins and who and which protein has which type and amount of network control including a detailed heatmap of the A.thaliana response distinguishing between two states of the immune response. (iii) In an immune response network of dendritic cells confronted with Aspergillus fumigatus, JimenaE calculates now accurately the specific values for centralities and protein-specific network control including chemokine and pattern recognition receptors
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