Kinetics of the interactions between yeast elongation factors 1A and 1Bα, guanine nucleotides, and aminoacyl-tRNA.

The interactions of elongation factor 1A (eEF1A) from Saccharomyces cerevisiae with elongation factor 1Bα (eEF1Bα), guanine nucleotides, and aminoacyl-tRNA were studied kinetically by fluorescence stopped-flow. eEF1A has similar affinities for GDP and GTP, 0.4 and 1.1 μM, respectively. Dissociation of nucleotides from eEF1A in the absence of the guanine nucleotide exchange factor is slow (about 0.1 s(−1)) and is accelerated by eEF1Bα by 320-fold and 250-fold for GDP and GTP, respectively. The rate constant of eEF1Bα binding to eEF1A (10(7)–10(8) M(−1) s(−1)) is independent of guanine nucleotides. At the concentrations of nucleotides and factors prevailing in the cell, the overall exchange rate is expected to be in the range of 6 s(−1), which is compatible with the rate of protein synthesis in the cell. eEF1A·GTP binds Phe-tRNA(Phe) with a K(d) of 3 nM, whereas eEF1A·GDP shows no significant binding, indicating that eEF1A has similar tRNA binding properties as its prokaryotic homolog, EF-Tu

Kinetics of the interactions between yeast elongation factors 1A and 1Bα, guanine nucleotides, and aminoacyl-tRNA.

Cette édition critique du Muntaḫab-i Jōg Bāsišt, complétée par une traduction soigneuse en anglais (pp. 53-153) et encadrée d’introductions en anglais (pp. 5-49) et en persan (pp. 1-27) constitue une contribution importante pour les études sur les contacts entre l’islam et le monde indien à l’époque moderne. Fatḥullāh Mojtabā’ī a enfin publié cette étude, longtemps après sa thèse de doctorat soutenue en 1976 et qui avait eu ce texte pour objet. Le Muntaḫab-i Jōg Bāsišt est un compendium persa..

Integration of field bus and MAP networks - hierarchical communication systems in production environments

SIGLETIB Hannover: RO 6925(89-15) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Social Computing : Bridging the Gap Between the Social and the Technical

Abstract. Developing cooperative systems and social media requires taking complex decisions concerning the social interaction to be supported as well as the technical foundation. In this paper we build on the long and successful tradi-tion of design patterns and the social framework of Erving Goffman. We pre-sent design patterns that address both challenges of social interaction and tech-nical foundation—they provide input for software developers with respect to structuring software and to providing adequate support for the interaction of us-ers with the environment and with each other

POLIWORK - Telekooperation und Dokumentenverwaltung am persoenlichen Arbeitsplatz Abschlussbericht

In the research project POLIWORK, an integrated application suite based on standard components for the support of secure multipoint multimedia tele-conferencing was developed and evaluated. To meet this goal, four partners from research and industry co-operated with end users in two federal ministries. An iterative approach was chosen for POLIWORK to provide a first prototype of the system to the user community as soon as possible. The objectives of the POLIWORK project can be outlined as follows. 1. To further develop and evaluate technical solutions to support tele-cooperation together with the end users, 2. To analyze the impact of telecooperation technologies on the organizational structures within federal administration, and 3. To develop a set of suggestions for the organizational efforts that have to be taken when introducing new tele-cooperation technology into organizations. The focus of GMD within POLIWORK was on the technical conception and realization of tele-cooperation solutions (see point 1 above) and covered the following areas: Multipoint audio/video conferencing. Scheduling and conducting multipoint multimedia tele-conferences. Cooperative document repository. Administrative modelling of users, groups, and technical infrastructure. Development of a single, integrated user interface. For each of these aspects, existing technical solutions were evaluated, new solutions were developed and subsequently brought into the field. The goal of the conception and realization of the IT solution was developing a system which is distributed over multiple locations and which provides appropriate support for collaboration and communication. In doing so, it was important to take into account that the different user groups use various existing applications for their everyday tasks which need to be supported. Also, for supporting the different application scenarios, different configurations of the solution would be required. The report at hand covers the GMD's activities of the POLIWORK project, covering the time between Aug 1"s"t, 1996 and December 31"s"t, 1998. (orig.)SIGLEAvailable from TIB Hannover: F99B615+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman