984 research outputs found

    Lysosomal enzyme precursors in coated vesicles derived from the exocytic and endocytic pathways.

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    The molecular forms of two lysosomal enzymes, cathepsin C and cathepsin D, have been examined in lysosomes and coated vesicles (CVs) of rat liver. In addition, the relative proportion of these lysosomal enzymes residing in functionally distinct CV subpopulations was quantitated. CVs contained newly synthesized precursor forms of the enzymes in contrast to lysosomes where only the mature forms were detected. Exocytic and endocytic CV subpopulations were prepared by two completely different protocols. One procedure, a density shift method, uses cholinesterase to alter the density of CVs derived from exocytic or endocytic pathways. The other relies on electrophoretic heterogeneity to accomplish the CV subfractionation. Subpopulations of CVs prepared by either procedure showed similar results, when examined for their relative proportion of cathepsin C and cathepsin D precursors. Within the starting CV preparation, exocytic CVs contained approximately 80-90% of the total steady-state levels of these enzymes while the level in the endocytic population was approximately 10-13%. The implications of these findings are discussed with regard to lysosome trafficking

    The RMS Survey: Ammonia and water maser analysis of massive star forming regions

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    The Red MSX Source (RMS) survey has identified a sample of ~1200 massive young stellar objects (MYSOs), compact and ultra compact HII regions from a sample of ~2000 MSX and 2MASS colour selected sources. We have used the 100 m Green Bank telescope to search for 22-24 GHz water maser and ammonia (1,1), (2,2) and (3,3) emission towards ~600 RMS sources located within the northern Galactic plane. We have identified 308 H2O masers which corresponds to an overall detection rate of ~50%. Abridged: We detect ammonia emission towards 479 of these massive young stars, which corresponds to ~80%. Ammonia is an excellent probe of high density gas allowing us to measure key parameters such as gas temperatures, opacities, and column densities, as well as providing an insight into the gas kinematics. The average kinetic temperature, FWHM line width and total NH3 column density for the sample are approximately 22 K, 2 km/s and 2x10^{15} cm^{-2}, respectively. We find that the NH3 (1,1) line width and kinetic temperature are correlated with luminosity and finding no underlying dependence of these parameters on the evolutionary phase of the embedded sources, we conclude that the observed trends in the derived parameters are more likely to be due to the energy output of the central source and/or the line width-clump mass relationship. The velocities of the peak H2O masers and the NH3 emission are in excellent agreement with each other, which would strongly suggest an association between the dense gas and the maser emission. Moreover, we find the bolometric luminosity of the embedded source and the isotropic luminosity of the H2O maser are also correlated. We conclude from the correlations of the cloud and water maser velocities and the bolometric and maser luminosity that there is a strong dynamical relationship between the embedded young massive star and the H2O maser.Comment: 17 pages and 17 figures and 8 tables. Tables\,2 and 5 and full versions of Figs. 3 and 7 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.125.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A

    Minimum weight design of axially compressed ring and stringer stiffened cylindrical shells

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    Minimum weight design of axially compressed ring and stringer stiffened cylindrical shell

    Уроборос и другие экстернальные эффекты полевой научной инфраструктуры

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    Acknowledgments: The results of the project "Infrastructure of Scientific Knowledge and Territorial Development", carried out within the framework of the Basic Research Program at the National Research University Higher School of Economics (HSE University) in 2019, are presented in this work. The article examines the functioning of the field research infrastructure (marine biological stations, specially protected natural areas, museum-reserves) in terms of the external effects it generates. These processes are described in the context of contemporary transformations of the conservation policy in Russia. The proposed analytical typology of these types of impact includes a consideration of negative and positive externalities - both those associated with the scientific activity itself (the emergence of private research stations) and the emergence of new economic forms of activity (tourism) - as well as the spread of new social practices. The paradoxical "Ouroboros effect" has been identified and described: the principle of noninterference, implicit in the conservation regime, in some cases prevents the use of measures aimed at saving protected flora and fauna. Examples of how these external effects contribute to the processes of touristifica-tion, revitalization, and gentrification of rural areas are also considered. Particular attention is paid to the role of scholars in the formation of local historical and cultural identity. Overall, the study allows us to draw a general conclusion about the significant and diverse effects of the presence of field research infrastructure on home territories, effects not directly related to the core activities of these institutions. The emergence of these effects is determined by the concentration, in research stations, of people with a high level of cultural capital. These people may foster the emergence of new forms of economic activity in the territory, as well as acts as the transmitters of social and organisational practices new to this local context

    IRIS: Efficient Visualization, Data Analysis and Experiment Management for Wireless Sensor Networks

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    The design of ubiquitous computing environments is challenging, mainly due to the unforeseeable impact of real-world environments on the system performance. A crucial step to validate the behavior of these systems is to perform in-field experiments under various conditions. We introduce IRIS, an experiment management and data processing tool allowing the definition of arbitrary complex data analysis applications. While focusing on Wireless Sensor Networks, IRIS supports the seamless integration of heterogeneous data gathering technologies. The resulting flexibility and extensibility enable the definition of various services, from experiment management and performance evaluation to user-specific applications and visualization. IRIS demonstrated its effectiveness in three real-life use cases, offering a valuable support for in-field experimentation and development of customized applications for interfacing the end user with the system
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