170 research outputs found

    More on Electric and Magnetic Fluxes in SU(2)

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    The free energies of static charges and center monopoles are given by their fluxes. While electric fluxes show the universal behaviour of the deconfinement transition, the monopole free energies vanish in the thermodynamic limit at all temperatures and are thus irrelevant for the transition. Magnetic fluxes may, however, be used to measure the topological susceptibility without cooling.Comment: 3 pages, LaTeX2e (ws-procs9x6.cls), 1 eps-figure, talk presented by L.v.S. at Quark Confinement and the Hadron Spectrum V, Gargnano, Italy, September 10-14, 200

    More on electric and magnetic fluxes in SU(2)

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    Also published in: arXiv:hep-lat/0212019v1, 12 Dec 2002: 1-3The free energies of static charges and center monopoles are given by their fluxes. While electric fluxes show the universal behaviour of the deconfinement transition, the monopole free energies vanish in the thermodynamic limit at all temperatures and are thus irrelevant for the transition. Magnetic fluxes may, however, be used to measure the topological susceptibility without cooling.Lorenz von Smekal with Philippe de Forcrand and Oliver Jah

    Strategien zur Bekämpfung von Brandkrankheiten bei Getreide im Ökologischen Landbau

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    Getreidebrände als saatgutübertragbare Erkrankungen der Ähre haben im Ökologischen Landbau stärkere Bedeutung erlangt, weil eine Beizung mit hochwirksamen Fungiziden unterbleibt. Eine Bekämpfung ist jedoch zwingend notwendig, weil in der Regel Ertragseinbußen eintreten und die Sporen toxikologisch bedenklich sind. Zudem droht der Saatgutvermehrung Schaden, denn bereits mehr als drei bzw. fünf befallene Pflanzen pro 150 m² führen zur Aberkennung des Basis- bzw. Z-Saatgutes. Resistente Sorten stehen kaum zur Verfügung, denn wegen der Saatbeizung bestand für die Züchtung seit Jahrzehnten keine Notwendigkeit, sich einer Resistenzzüchtung zu widmen. Das spiegelt sich auch in den Zulassungskriterien des Bundessortenamtes wider, wo die Anfälligkeit der Sorten auf Brandkrankheiten nicht berücksichtigt wird. Bei den relevanten Brandkrankheiten handelt es sich bei allen Triticum-Arten um Steinbrand (Tilletia tritici), Zwergsteinbrand (Tilletia controversa) und Flugbrand (Ustilago tritici), bei Gerste um Flugbrand (U. nuda) und Hartbrand (U. hordei) sowie bei Hafer um Flugbrand (U. avenae). Die Bekämpfung der Getreidebrände im Öko-Landbau ist spätestens seit der EU-Verordnung Nr. 1452/2003, welche die Verwendung von Saatgut aus ökologischem Anbau vorschreibt, eine vordringliche Aufgabe der Forschung. In Deutschland werden derzeit verschiedene Forschungsvorhaben zu dieser Problematik durchgeführt (Wilbois et al. 2005; Spieß 2006)

    Stand der Bekämpfung von Brandkrankheiten im ökologischen Getreidebau

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    With the aim to evaluate the effectiveness of techniques and measures for control of cereal bunts and smuts in organic farming systems, field trials were carried out in multiple locations from 2004 to 2006. The relevant fungal diseases included in the trials were common bunt (Tilletia tritici), dwarf bunt (T. controversa), loose smut (Usti-lago tritici, U. nuda), covered smut (U. hordei) and black loose smut (U. avenae). The following treatments were found to be effective. Common bunt: different physical methods, Tillecur, acetic acid. Loose smut of barley and wheat: warm and hot water treatment, seed treatment with ethanol (more trials needed). Covered smut of barley: warm water treatment, ethanol, Lebermooser. Loose smut of oats: hot water treat-ment, ethanol. Field resistant varieties are available (although in some cases only in limited number) for common bunt, loose smut of wheat and barley and covered smut. The status of varietal resistance against dwarf bunt is only insufficiently known. In case of black loose smut research on resistant varieties is currently being conducted

    Open Power System Data - Frictionless data for electricity system modelling

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    The quality of electricity system modelling heavily depends on the input data used. Although a lot of data is publicly available, it is often dispersed, tedious to process and partly contains errors. We argue that a central provision of input data for modelling has the character of a public good: it reduces overall societal costs for quantitative energy research as redundant work is avoided, and it improves transparency and reproducibility in electricity system modelling. This paper describes the Open Power System Data platform that aims at realising the efficiency and quality gains of centralised data provision by collecting, checking, processing, aggregating, documenting and publishing data required by most modellers. We conclude that the platform can provide substantial benefits to energy system analysis by raising efficiency of data pre-processing, providing a method for making data pre-processing for energy system modelling traceable, flexible and reproducible and improving the quality of original data published by data providers.Comment: This is the postprint version of the articl

    Genomic SELEX for Hfq-binding RNAs identifies genomic aptamers predominantly in antisense transcripts

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    An unexpectedly high number of regulatory RNAs have been recently discovered that fine-tune the function of genes at all levels of expression. We employed Genomic SELEX, a method to identify protein-binding RNAs encoded in the genome, to search for further regulatory RNAs in Escherichia coli. We used the global regulator protein Hfq as bait, because it can interact with a large number of RNAs, promoting their interaction. The enriched SELEX pool was subjected to deep sequencing, and 8865 sequences were mapped to the E. coli genome. These short sequences represent genomic Hfq-aptamers and are part of potential regulatory elements within RNA molecules. The motif 5′-AAYAAYAA-3′ was enriched in the selected RNAs and confers low-nanomolar affinity to Hfq. The motif was confirmed to bind Hfq by DMS footprinting. The Hfq aptamers are 4-fold more frequent on the antisense strand of protein coding genes than on the sense strand. They were enriched opposite to translation start sites or opposite to intervening sequences between ORFs in operons. These results expand the repertoire of Hfq targets and also suggest that Hfq might regulate the expression of a large number of genes via interaction with cis-antisense RNAs

    First evidence of Renlandian (c. 950–940 Ma) orogeny in mainland Scotland:Implications for the status of the Moine Supergroup and circum-North Atlantic correlations

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    Central problems in the interpretation of the Neoproterozoic geology of the North Atlantic region arise from uncertainties in the ages of, and tectonic drivers for, Tonian orogenic events recorded in eastern Laurentia and northern Baltica. The identification and interpretation of these events is often problematic because most rock units that record Tonian orogenesis were strongly reworked at amphibolite facies during the Ordovician-Silurian Caledonian orogeny. Lu-Hf and Sm-Nd geochronology and metamorphic modelling carried out on large (>1 cm) garnets from the Meadie Pelite in the Moine Nappe of the northern Scottish Caledonides indicate prograde metamorphism between 950 and 940 Ma at pressures of 6–7 kbar and temperatures of 600 °C. This represents the first evidence for c. 950 Ma Tonian (Renlandian) metamorphism in mainland Scotland and significantly extends its geographic extent along the palaeo-Laurentian margin. The Meadie Pelite is believed to be part of the Morar Group within the Moine Supergroup. If this is correct: 1) the Morar Group was deposited between 980 ± 4 Ma (age of the youngest detrital zircon; Peters, 2001, youngest published zircon date is 947 ± 189 (Friend et al., 2003)) and c. 950 Ma (age of regional metamorphism reported here), 2) an orogenic unconformity must separate the Morar Group from the 883 ± 35 Ma (Cawood et al., 2004) Glenfinnan and Loch Eil groups, and 3) the term ‘Moine Supergroup’ may no longer be appropriate. The Morar Group is broadly correlative with similar aged metasedimentary successions in Shetland, East Greenland, Svalbard, Ellesmere Island and northern Baltica. All these successions were deposited after c. 1030 Ma, contain detritus from the Grenville orogen, and were later deformed and metamorphosed at 950–910 Ma during accretionary Renlandian orogenesis along an active plate margin developed around this part of Rodinia

    Constraining long-term denudation and faulting history in intraplate regions by multisystem thermochronology: An example of the Sudetic Marginal Fault (Bohemian Massif, central Europe)

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    The Rychlebské hory Mountain region in the Sudetes (NE Bohemian Massif) provides a natural laboratory for studies of postorogenic landscape evolution. This work reveals both the exhumation history of the region and the paleoactivity along the Sudetic Marginal Fault (SMF) using zircon (U-Th)/He (ZHe), apatite fission track (AFT), and apatite (U-Th)/He (AHe) dating of crystalline basement and postorogenic sedimentary samples. Most significantly, and in direct contradiction of traditional paleogeographic reconstructions, this work has found evidence of a large Cretaceous sea and regional burial (to >6.5 km) of the Carboniferous-Permian basement in the Late Cretaceous (~95–80 Ma). During the burial by sediments of the Bohemian Cretaceous Basin System, the SMF acted as a normal fault as documented by offset ZHe ages across the fault. At 85–70 Ma, the basin was inverted, Cretaceous strata eroded, and basement blocks were exhumed to the near surface at a rate of ~300 m/Ma as evidenced by Late Cretaceous–Paleocene AFT ages and thermal modeling results. There is no appreciable difference in AFT and AHe ages across the fault, suggesting that the SMF acted as a reverse fault during exhumation. In the late Eocene–Oligocene, the basement was locally heated to <70°C by magmatic activity related to opening of the Eger rift system. Neogene or younger thermal activity was not recorded in the thermochronological data, confirming that late Cenozoic uplift and erosion of the basement blocks was limited to less than ∼1.5 km in the study area

    Variability in the analysis of a single neuroimaging dataset by many teams

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    Data analysis workflows in many scientific domains have become increasingly complex and flexible. To assess the impact of this flexibility on functional magnetic resonance imaging (fMRI) results, the same dataset was independently analyzed by 70 teams, testing nine ex-ante hypotheses. The flexibility of analytic approaches is exemplified by the fact that no two teams chose identical workflows to analyze the data. This flexibility resulted in sizeable variation in hypothesis test results, even for teams whose statistical maps were highly correlated at intermediate stages of their analysis pipeline. Variation in reported results was related to several aspects of analysis methodology. Importantly, meta-analytic approaches that aggregated information across teams yielded significant consensus in activated regions across teams. Furthermore, prediction markets of researchers in the field revealed an overestimation of the likelihood of significant findings, even by researchers with direct knowledge of the dataset. Our findings show that analytic flexibility can have substantial effects on scientific conclusions, and demonstrate factors related to variability in fMRI. The results emphasize the importance of validating and sharing complex analysis workflows, and demonstrate the need for multiple analyses of the same data. Potential approaches to mitigate issues related to analytical variability are discussed
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