4,285 research outputs found

    Kinetic equations for Stark line shapes

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    The BBGKY formalism is revisited in the framework of plasma spectroscopy. We address the issue of Stark line shape modeling by using kinetic transport equations. In the most simplified treatment of these equations, triple correlations between an emitter and the perturbing charged particles are neglected and a collisional description of Stark effect is obtained. Here we relax this assumption and retain triple correlations using a generalization of the Kirkwood truncature hypothesis to quantum operator. An application to hydrogen lines is done in the context of plasma diagnostic, and indicates that the neglect of triple correlations can lead to a significant overestimate of the line width.Comment: 13 pages, 1 figur

    Femtosecond x-ray absorption spectroscopy of spin and orbital angular momentum in photoexcited Ni films during ultrafast demagnetization

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    We follow for the first time the evolution of the spin and orbital angular momentum of a thin Ni film during ultrafast demagnetization, by means of x-ray magnetic circular dichroism. Both components decrease with a 130 +/- 40 fs time constant upon excitation with a femtosecond laser pulse. Additional x-ray absorption measurements reveal an increase in the spin-orbit interaction by 6 +/- 2 % during this process. This is the experimental demonstration quantifying the importance of spin-orbit mediated processes during the demagnetization

    The Inferred Cardiogenic Gene Regulatory Network in the Mammalian Heart

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    Cardiac development is a complex, multiscale process encompassing cell fate adoption, differentiation and morphogenesis. To elucidate pathways underlying this process, a recently developed algorithm to reverse engineer gene regulatory networks was applied to time-course microarray data obtained from the developing mouse heart. Approximately 200 genes of interest were input into the algorithm to generate putative network topologies that are capable of explaining the experimental data via model simulation. To cull specious network interactions, thousands of putative networks are merged and filtered to generate scale-free, hierarchical networks that are statistically significant and biologically relevant. The networks are validated with known gene interactions and used to predict regulatory pathways important for the developing mammalian heart. Area under the precision-recall curve and receiver operator characteristic curve are 9% and 58%, respectively. Of the top 10 ranked predicted interactions, 4 have already been validated. The algorithm is further tested using a network enriched with known interactions and another depleted of them. The inferred networks contained more interactions for the enriched network versus the depleted network. In all test cases, maximum performance of the algorithm was achieved when the purely data-driven method of network inference was combined with a data-independent, functional-based association method. Lastly, the network generated from the list of approximately 200 genes of interest was expanded using gene-profile uniqueness metrics to include approximately 900 additional known mouse genes and to form the most likely cardiogenic gene regulatory network. The resultant network supports known regulatory interactions and contains several novel cardiogenic regulatory interactions. The method outlined herein provides an informative approach to network inference and leads to clear testable hypotheses related to gene regulation

    Nouveaux Orthoptères (Ensifera, Insecta) du Trias des Vosges (France)

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    Three new Orthoptera, Ensifera (Hagloidea and Gryllavoidea) from the Grés à Voltzia (Upper Buntsandstein, transition Lower / Middle Triassic) of the Vosges (France) are described based on forewings. Galliagryllavus vogesiacus n.gen., n.sp. (Gryllavidae) shows affinities with Gryllavus madygenicus SHAROV 1968 from the Triassic of Madygen (Kirghizistan). Triassoparacyrtophyllites bifurcatus n.gen., n.sp. (Tuphellidae) displays some similarities with Paracyrtophillites undulatus SHAROV 1968 from the Upper Jurassic of Karatau (Kazakhstan). Voltziahagla pseudoveinosa n.gen., n.sp. (Haglidae) seems close to the genus Archaboilus MARTYNOV 1937 from the Lower Jurassic of Shurab (Tadjikistan). These three Ensifera which belong to distinct families underscore the diversity of the Hagloidea and the Gryllavoidea at the boundary between the Lower and Middle Triassic. A cladistic study would be necessary to determine the phylogenetical relationships between the different families

    Optimization of delivery adherence based on capacity planning and bid pricing

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    Sales revenues of enterprises are often subject to seasonal fluctuation. This leads to high or low utilized resources and this in turn to revenue losses. Hence, the enterprises invest a high effort to improve long and short-term resource utilization. In this context, disregarding future capacity utilization within the process of quotation leads to short-timed capacity adjustments for instance, additional work hours across seasons. This paper presents an approach which focuses on dependencies between costs and capacity by linking cost pricing and production scheduling. A first evaluation at an MTO supplier shows that order delays can be reduced by up to 95% and total costs by 21% compared to using the most appropriate priority rule
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