6,004 research outputs found

    Contributions to the flora and vegetation of Kagbeni (Mustan District, Central Nepal)

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    Kagbeni and its irrigated oasis are surrounded by subdesert dwarf scrubland. In the present study, a list of 78 species of vascular plants is presented for Kagbeni and its immediate surroundings, supplemented with data on the distribution of the species within the entire Mustan District. The data are arrived from own investigations and the geobotanical literature. A phytogeographical analysis shows the prevalence of western over eastern elements. Species with a wide distribution in Eurasia, which constitute one third of the total flora of Kagbeni, are of great importance as weeds on arable fields and in ruderal places within the irrigated oasis. Their occurrence is closely related to human activity. Presumably, most of these weeds have reached the area under study in connection with agriculture a long time ago. Weeds from the New World, although recorded in other villages of Mustan District, have not been found in Kagbeni. The weed vegetation of Kagbeni is documented by nine vegetation releves, and is compared to releves from Jomsom and Mzrpha. A floristic gradient from south to north that has been detected by earlier investigations throughout the whole district can be reproduced at the local scale. With regard to the weed flora, the effects of different crops are minimal, compared to effects of altitude and other factors related to altitude

    Coupling a single electron on superfluid helium to a superconducting resonator.

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    Electrons on helium form a unique two-dimensional system on the interface of liquid helium and vacuum. A small number of trapped electrons on helium exhibits strong interactions in the absence of disorder, and can be used as a qubit. Trapped electrons typically have orbital frequencies in the microwave regime and can therefore be integrated with circuit quantum electrodynamics (cQED), which studies light-matter interactions using microwave photons. Here, we experimentally realize a cQED platform with the orbitals of single electrons on helium. We deterministically trap one to four electrons in a dot integrated with a microwave resonator, allowing us to study the electrons' response to microwaves. Furthermore, we find a single-electron-photon coupling strength of [Formula: see text] MHz, greatly exceeding the resonator linewidth [Formula: see text] MHz. These results pave the way towards microwave studies of Wigner molecules and coherent control of the orbital and spin state of a single electron on helium

    Farm level environmental indicators; are they useful? An overview of Green Accounting Systems for European farms

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    Green accounts or Input-Output Accounting systems (IOA) have been developed in countries with intensive agricultural production to facilitate voluntary improvements in farm environmental performance. There is a need for an overview of indicators used and a review of results and experiences reported. Ten IOA systems covering the topics of the farm's use of nutrients, pesticides and energy were selected from a survey of 55 systems and compared in this paper. The approaches and indicators used vary from systems based on Good Agricultural Practices (GAP) to accounts based systems that use physical input-output units. Many IOA systems use farm gate nutrient balances, pesticide use per ha and energy use per kg product. These indicators are easy to calculate but the resulting value needs separate interpretation for the farmer. Other systems include modelled emissions and rate the yearly farm results using closed scales, which allows for easy interpretation but builds on implicit normative assumptions of best practices. Participating farmers were most often reported to be motivated for the use of IOA but empirical evidence of improved environmental farm performance was scarce. IOA systems should be linked with production planning tools used by the advisory services. Farmers and advisors needs better reference values to evaluate the indicator levels (environmental performance) on the individual farm possibly based on analysis of a larger number of farms. The statistical properties of IOA indicators need to be researched regarding: (1) The relation between changed management practice and changes in indicator values on a given farm over a period of time. (2) The relative importance of systematic vs. coincidental differences in environmental performance of a set of farms. It is concluded that IOA systems could become effective tools for agri-environmental improvement of European farms given further development and standardisation

    Biological bibliography online : BioLIS

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    Die Datenbank BioLIS wird durch die Universitätsbibliothek Johann Christian Senckenberg (Frankfurt/M.) kostenfrei online zur Verfügung gestellt. Sie weist deutsche biologische Zeitschriftenliteratur aus dem Zeit¬raum 1970 bis 1996 nach – damit ist BioLIS eine wesentliche Ergänzung zu der Datenbank „Biological Abstracts“. Die bibliografischen Angaben zu den nachgewiesenen Aufsätzen werden durch umfassende Schlagwörter und Namen behandelter Organismen ergänzt, so dass Spezialrecherchen insbesondere nach Literatur über bestimmte Organismen möglich sind.The database BioLIS is provided online by the University Library Johann Christian Senckenberg (Frankfurt/Main, Germany). Originally conceived as a supplement to „Biological Abstracts“, BioLIS comprises metadata on german biological journal papers from the period 1970 to 1996

    Review of the BCI competition IV

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    Die Entwicklung der britischen Elektrizitätswirtschaft nach der Sozialisierung

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    Bibliographic records of botanical literature on Hesse : present state and prospects

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    Die Möglichkeiten zum Recherchieren von botanischer Literatur über Hessen in sieben Online-Datenbanken werden vergleichend betrachtet. Unter anderem werden Testrecherchen zu Beiträgen in den Zeitschriften Hessische Floristische Briefe und Botanik und Naturschutz in Hessen ausgewertet. Es stellt sich heraus, dass im Feld der getesteten Datenbanken die Hessische Bibliographie sowie Biological Abstracts jeweils eine besondere Stellung einnehmen; mehrere weitere, überwiegend lizenzfrei nutzbare Datenbanken liefern ebenfalls substanzielle Beiträge. Die von der Universitätsbibliothek Johann Christian Senckenberg in Frankfurt am Main aufgebaute Virtuelle Fachbibliothek Biologie (vifabio) erleichtert den Zugang zu einigen wesentlichen Ressourcen; unter anderem können Hessische Bibliographie und Biological Abstracts sowie weitere Datenbanken in vifabio mit einer einzigen Suchanfrage parallel durchsucht werden.The possibilities for researching botanical literature on Hesse were compared in seven online databases. Results of test searches for papers in the journals Hessische Floristische Briefe und Botanik und Naturschutz in Hessen, amongst others, were evaluated. It turns out that, amongst the field of tested databases, the Hessian Bibliography and Biological Abstracts place well. Several other, predominantly license-free usable databases offer similar substantial contributions. The Virtual Library of Biology (vifabio), developed by the University Library Johann Christian Senckenberg in Frankfurt am Main, enables access to several fundamental resources; in vifabio, the Hessian Bibliography and Biological Abstracts (for German academic institutions), as well as other databases, can be searched simultaneously with a single query

    ECoG high gamma activity reveals distinct cortical representations of lyrics passages, harmonic and timbre-related changes in a rock song

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    Listening to music moves our minds and moods, stirring interest in its neural underpinnings. A multitude of compositional features drives the appeal of natural music. How such original music, where a composer's opus is not manipulated for experimental purposes, engages a listener's brain has not been studied until recently. Here, we report an in-depth analysis of two electrocorticographic (ECoG) data sets obtained over the left hemisphere in ten patients during presentation of either a rock song or a read-out narrative. First, the time courses of five acoustic features (intensity, presence/absence of vocals with lyrics, spectral centroid, harmonic change, and pulse clarity) were extracted from the audio tracks and found to be correlated with each other to varying degrees. In a second step, we uncovered the specific impact of each musical feature on ECoG high-gamma power (70–170 Hz) by calculating partial correlations to remove the influence of the other four features. In the music condition, the onset and offset of vocal lyrics in ongoing instrumental music was consistently identified within the group as the dominant driver for ECoG high-gamma power changes over temporal auditory areas, while concurrently subject-individual activation spots were identified for sound intensity, timbral, and harmonic features. The distinct cortical activations to vocal speech-related content embedded in instrumental music directly demonstrate that song integrated in instrumental music represents a distinct dimension in complex music. In contrast, in the speech condition, the full sound envelope was reflected in the high gamma response rather than the onset or offset of the vocal lyrics. This demonstrates how the contributions of stimulus features that modulate the brain response differ across the two examples of a full-length natural stimulus, which suggests a context-dependent feature selection in the processing of complex auditory stimuli
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