12,762 research outputs found

    Generation of specific antibodies against the rap1A, rap1B and rap2 small GTP-binding proteins. Analysis of rap and ras proteins in membranes from mammalian cells

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    Specific antibodies against rap1A and rap1B small GTP-binding proteins were generated by immunization of rabbits with peptides derived from the C-terminus of the processed proteins. Immunoblot analysis of membranes from several mammalian cell lines and human thrombocytes with affinity-purified antibodies against rap1A or rap1B demonstrated the presence of multiple immunoreactive proteins in the 22-23 kDa range, although at strongly varying levels. Whereas both proteins were present in substantial amounts in membranes from myelocytic HL-60, K-562 and HEL cells, they were hardly detectable in membranes from lymphoma U-937 and S49.1 cyc- cells. Membranes from human thrombocytes and 3T3-Swiss Albino fibroblasts showed strong rap1B immunoreactivity, whereas rap1A protein was present in much lower amounts. In the cytosol of HL-60 cells, only small amounts of rap1A and rap1B proteins were detected, unless the cells were treated with lovastatin, an inhibitor of hydroxymethylglutaryl-coenzyme A reductase, suggesting that both proteins are isoprenylated. By comparison with recombinant proteins, the ratio of rap1A/ras proteins in membranes from HL-60 cells was estimated to be about 4:1. An antiserum directed against the C-terminus of rap2 reacted strongly with recombinant rap2, but not with membranes from tested mammalian cells. In conclusion, rap1A and rap1B proteins are distributed differentially among membranes from various mammalian cell types and are isoprenylated in HL-60 cells

    A transient heat transfer and thermodynamic analysis of the Apollo service module propulsion system. Vol. I, phase I - Transient thermal analysis Final report, 28 Jul. 1964 - 28 Jul. 1965

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    Transient heat transfer and thermodynamic behavior analysis for Apollo service module propulsion system - fuel cell effect on overheatin

    Influenced of Fe buffer thickness on the crystalline quality and the transport properties of Fe/Ba(Fe1-xCox)2As2 bilayers

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    The implementation of an Fe buffer layer is a promising way to obtain epitaxial growth of Co-doped BaFe2As2 (Ba-122). However, the crystalline quality and the superconducting properties of Co-doped Ba-122 are influenced by the Fe buffer layer thickness, dFe. The well-textured growth of the Fe/Ba-122 bilayer with dFe = 15 nm results in a high Jc of 0.45 MAcm−2^{-2} at 12 K in self-field, whereas a low Jc value of 61000 Acm−2^{-2} is recorded for the bilayer with dFe = 4 nm at the corresponding reduced temperature due to the presence of grain boundaries

    Deployable antenna phase A study

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    Applications for large deployable antennas were re-examined, flight demonstration objectives were defined, the flight article (antenna) was preliminarily designed, and the flight program and ground development program, including the support equipment, were defined for a proposed space transportation system flight experiment to demonstrate a large (50 to 200 meter) deployable antenna system. Tasks described include: (1) performance requirements analysis; (2) system design and definition; (3) orbital operations analysis; and (4) programmatic analysis

    A quasi classical approach to fully differential ionization cross sections

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    A classical approximation to time dependent quantum mechanical scattering in the M\o{}ller formalism is presented. Numerically, our approach is similar to a standard Classical-Trajectory-Monte-Carlo calculation. Conceptually, however, our formulation allows one to release the restriction to stationary initial distributions. This is achieved by a classical forward-backward propagation technique. As a first application and for comparison with experiment we present fully differential cross sections for electron impact ionization of atomic hydrogen in the Erhardt geometry.Comment: 6 pages, 2 figure

    Dispatcher3: Innovative processing for flight practices

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    An experienced dispatcher will have a good understanding on the differences between planned and executed flight plans. These differences will be driven by uncertainty factors such as, which runway is the one that will be used at arrival, what is the actual weather that the flight will experience, or how much delay will the flight experience as holding at the arrival. Besides safety aspects, dispatchers will consider, among other parameters, the operational environment and constraints (such as flight date and time, network congestion or route availability), the situation of the airline fleet (e.g., delays), airline policies and performance indicators (cost and on-time performance) to select the most suitable flight plan: route, profile and cost index. Some of these aspects can be automatised by using advanced flight dispatching and planning tools, but having a good understanding of the expected discrepancies between planned and realised, and of the key driving factors for these variations is key to produce robust and efficient solutions. Dispatcher3, an Innovative Action within the frame of CleanSky 2 ITD System, will provide a data infrastructure for levering on historical data and machine learning techniques to systematically estimate the variability between planned and executed flight plans. The project is led by the University of Westminster, with Innaxis, the Universitat Politecnica de Catalunya, Vueling Airlines, PACE Aerospace Engineering and Information Technology and skeyes as partners. The Topic Manager is Thales AVS France SAS. Dispatcher3 focuses on the activities prior to departure and aims at supporting dispatchers, pilots and the strategic scheduling process. * Dispatchers will benefit from * predictions of the expected actual performance of a flight, * advice on the flight plan design and selection process, and * identification of the key driving factors for the variations between planning and execution. * The flight crew will obtain * information on the expected variance between the flight plan and the flight execution, and * qualitative advice on some flight operations. * Schedule planners will count with an infrastructure able to identify which flights are systematically prone to variations between schedules and execution blocks requiring the need of further assessment. Dispatcher3 is organised in three layers: * Data infrastructure: Powered by DataBeacon (a multi-sided, open source, data storage and processing platform). It provides private environments to perform analytical and modelling tasks, secure data fusion, and a cloud computing scalable infrastructure; * Predictive capabilities; with two different modules: * Data acquisition and preparation: with a first phase of data wrangling and a second step of descriptive analytics. * Predictive modelling: following the standard machine learning pipeline of target variable labelling, feature engineering, and finally training, testing and validation of machine learning models. * Advice capabilities: relying on the output of the predictive layer and producing specific advise to users: dispatchers, pilots and schedule planners. Dispatcher3 will consider datasets available within airlines, but also analyse which datasets are currently not accessible but could benefit these predictive capabilities. This quantification on the predictive improvement will help identify which multi-stakeholders collaborations should be established

    Visualização de dados de imagens de sensoriamento remoto.

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    Resumo: Geralmente, os dados de sensoriamento remoto são representados em imagens que reproduzem feições da superfície terrestre. Entretanto, imagens são compostas por dados quantitativos multivariados que podem ser trabalhados de diversas formas para produzir visualizações diferentes das reproduções pictóricas tradicionais. Dados que podem parecer sem valor, como das áreas cobertas por nuvens, podem revelar-se fonte de importante informação para o planejamento de trabalhos futuros. O Brasil tem grande importância na produção agrícola mundial e as culturas mais importantes no país são a soja, o milho e a cana-de-açúcar, que ocuparam 27,7, 15,9 e 8,7 milhões de hectares, respectivamente, na safra 2012/2013. Aproximadamente 40% desta produção se localiza em São Paulo, Paraná, Santa Catarina e Rio Grande do Sul. Imagens de satélite mostram potencial na estimativa de áreas ocupadas pela agricultura de larga escala. Entretanto, para que se possa obter imagens úteis é preciso que não haja nuvens, o que não é comum nos períodos chave dentro do calendário agrícola dessas culturas na região estudada. Obter imagens livres de nuvens ainda é um grande desafio para o monitoramento da agricultura em escala estadual ou nacional. Este trabalho objetivou demonstrar que o tratamento gráfico de dados oriundos de imagens de sensoriamento remoto pode produzir resultados úteis. Para tanto, foi analisada a frequência de imagens livres de nuvens sobre estados ou mesorregiões, ao longo dos meses, com base em uma série temporal de 2000 a 2013, a partir de dados obtidos pelo sensor MODIS e extraídos utilizando uma rotina do R. Abstract: Our goal was to demonstrate that the graph data processing of remote sensing images can produce useful results. We analyzed the frequency of cloud free images over Brazilian states, using a time series from 2000 to 2013, extracted from the MODIS sensor data and using a routine R

    GTI-space : the space of generalized topological indices

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    A new extension of the generalized topological indices (GTI) approach is carried out torepresent 'simple' and 'composite' topological indices (TIs) in an unified way. Thisapproach defines a GTI-space from which both simple and composite TIs represent particular subspaces. Accordingly, simple TIs such as Wiener, Balaban, Zagreb, Harary and Randićconnectivity indices are expressed by means of the same GTI representation introduced for composite TIs such as hyper-Wiener, molecular topological index (MTI), Gutman index andreverse MTI. Using GTI-space approach we easily identify mathematical relations between some composite and simple indices, such as the relationship between hyper-Wiener and Wiener index and the relation between MTI and first Zagreb index. The relation of the GTI space with the sub-structural cluster expansion of property/activity is also analysed and some routes for the applications of this approach to QSPR/QSAR are also given

    Infrared Spectroscopy of Quantum Crossbars

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    Infrared (IR) spectroscopy can be used as an important and effective tool for probing periodic networks of quantum wires or nanotubes (quantum crossbars, QCB) at finite frequencies far from the Luttinger liquid fixed point. Plasmon excitations in QCB may be involved in resonance diffraction of incident electromagnetic waves and in optical absorption in the IR part of the spectrum. Direct absorption of external electric field in QCB strongly depends on the direction of the wave vector q.{\bf q}. This results in two types of 1D→2D1D\to 2D dimensional crossover with varying angle of an incident wave or its frequency. In the case of QCB interacting with semiconductor substrate, capacitive contact between them does not destroy the Luttinger liquid character of the long wave QCB excitations. However, the dielectric losses on a substrate surface are significantly changed due to appearance of additional Landau damping. The latter is initiated by diffraction processes on QCB superlattice and manifests itself as strong but narrow absorption peaks lying below the damping region of an isolated substrate.SubmiComment: Submitted to Phys. Rev.
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