367 research outputs found

    Organization of geophysical parties for foreign exploration

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    Special conditions encountered in much foreign work make it necessary to consider many factors which are not encountered in domestic programs of geophysical exploration for oil. Although extremely difficult working conditions are frequently met in domestic operations by company and contract crews, the large store of past experience, the availability of fresh supplies, replacement or new equipment, and the proximity of the helpful home office make their surmountal more or less a matter of routine. Contrariwise, foreign operations are frequently conducted under much more difficult conditions, supplies and equipment can be secured only after long and costly delays, and the distance and inaccessibility of the home (executive) office leave practically all decisions to the party executive. With the rapidly increasing amount of foreign geophysical operations and the world wide extension in recent years of this activity, it is felt that special consideration of some of the problems encountered in the organization and operation of field parties for foreign service is pertinent and timely --Introduction, page 1

    Tramp and Scarecrow

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    (The) preparation and identification of meta-toluene sulfonic acid and of intermediates used in its preparation ..

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    Typewritten sheets in cover. Thesis (M.A.)--Boston University Bibliography: 1 p. at end

    Regulation of a subset of release-ready vesicles by the presynaptic protein Mover

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    Neurotransmitter release occurs by regulated exocytosis from synaptic vesicles (SVs). Evolutionarily conserved proteins mediate the essential aspects of this process, including the membrane fusion step and priming steps that make SVs release-competent. Unlike the proteins constituting the core fusion machinery, the SV protein Mover does not occur in all species and all synapses. Its restricted expression suggests that Mover may modulate basic aspects of transmitter release and short-term plasticity. To test this hypothesis, we analyzed synaptic transmission electrophysiologically at the mouse calyx of Held synapse in slices obtained from wild-type mice and mice lacking Mover. Spontaneous transmission was unaffected, indicating that the basic release machinery works in the absence of Mover. Evoked release and vesicular release probability were slightly reduced, and the paired pulse ratio was increased in Mover knockout mice. To explore whether Mover’s role is restricted to certain subpools of SVs, we analyzed our data in terms of two models of priming. A model assuming two SV pools in parallel showed a reduced release probability of so-called “superprimed vesicles” while “normally primed” ones were unaffected. For the second model, which holds that vesicles transit sequentially from a loosely docked state to a tightly docked state before exocytosis, we found that knocking out Mover selectively decreased the release probability of tight state vesicles. These results indicate that Mover regulates a subclass of primed SVs in the mouse calyx of Held

    Community Health as Community Partnerships

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    The article describes a project to improve health outcomes of a rural community by fostering collaboration among the health care providers, support systems, consumers, and community leaders. The presence of Ohio State University Extension was a key step in building the framework for collaboration. A Community Health Assessment was developed as a means to do a broad-based survey of community residents. The assessment focused on health education, health care, and financial concerns. Survey results showed that many resident concerns were directly related to the infrastructure of health in the community

    Principali reazioni termonucleari nelle stelle

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    Le reazioni termonucleari sono la principale sorgente di energia all’interno delle stelle e permettono alla struttura di restare in equilibrio anche per miliardi di anni. In questo elaborato si vuole mettere in mostra il ruolo fondamentale che esse ricoprono nell’evoluzione stellare, studiando nel dettaglio i processi principali e le differenti fasi che li costituiscono. Il primo capitolo fornisce fondamentali concetti di fisica atomica e dà una breve descrizione dei meccanismi di fusione e fissione nucleare. Il secondo capitolo descrive invece in dettaglio le reazioni termonucleari fondamentali per la formazione di elementi pesanti. Si studiano le varie catene protone-protone e gli alternativi cicli CNO per la fusione dell’idrogeno e i processi 3 alfa per la combustione dell’elio. Vengono poi analizzati alcuni dei processi per la formazione degli elementi più pesanti, come la cattura alfa o la cattura neutronica. Il paragrafo conclusivo descrive infine le condizioni di degenerazione di un plasma stellare, evidenziando le conseguenze più importanti dell’innesco di reazioni termonucleari in un gas degenere

    Innovation strategies for education: Liberal and Utilitarian Educational Tendencies in the Higher Education System

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    This paper discusses innovation strategies for education. The authors of the paper argue that the leading modern universities are the educational and training ones. The global changes in higher education have happened due to several reasons: information playing a key role in modern society (nowadays, it is possible to find plenty of information on any questions); the task of education is to develop educational, professional and cultural skills of students, which is not the original central idea of modern European countries as well as Russia; the tendency to unite several higher education institutions. The authors acknowledge that there are several trends in higher education: the multilevel system; modern information technologies; the distant educational system and development; university complexes; new educational standards; new educational technologies and management structures etc. At the same time, the authors claim that there are at least two systems (tendencies) in the theory of university development: liberal and pragmatic. The former is connected with the educational university’s mission; the later is related to the needs of modern society

    Lo stato dinamico di due ammassi stellari della Piccola Nube di Magellano tracciato dalla popolazione di Blue Stragglers

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    Gli ammassi globulari sono sistemi stellari dinamicamente attivi, la cui struttura interna viene progressivamente modificata dalle frequenti interazioni gravitazionali tra le stelle che li compongono (evoluzione dinamica), su tempi scala difficilmente prevedibili. In queste condizioni si formano anche le Blue Straggler Stars, stelle caratterizzate da una massa più alta della media e quindi soggette all'azione della frizione dinamica, che le fa progressivamente migrare verso le zone centrali dell'ammasso. Lo studio di numerosi ammassi globulari vecchi, localizzati nella Via Lattea e nella Grande Nube di Magellano, ha rivelato che il livello di segregazione delle Blue Stragglers è un potente indicatore dello stadio evolutivo del sistema ospite. È stato infatti riscontrato uno stretto legame tra il cosiddetto "parametro A+" (che misura appunto il grado di segregazione centrale delle Blue Stragglers) e parametri strutturali/dinamici del sistema che dipendono dalla sua età dinamica (come il raggio di core o il tempo di rilassamento centrale). Questo lavoro è volto allo studio della popolazione di Blue Stragglers in due ammassi della Piccola Nube di Magellano con età cronologica basso-intermedia (NGC 339, con età di 6 Gyr, e NGC 419, formatosi appena 1.5 Gyr fa), con l'obiettivo principale di determinarne lo stadio evolutivo. Grazie all'alta risoluzione angolare fornita da Hubble Space Telescope e alla disponibilità di osservazioni multi-epoca, è stato possibile misurare i moti propri delle stelle nella direzione dei due ammassi e separare cinematicamente le popolazioni membre da quelle di campo della Nube. Questo ha permesso di studiare la distribuzione radiale delle Blue Stragglers con un'accuratezza senza precedenti per degli ammassi extragalattici, ottenendo una solida conferma del fatto che il parametro A+ è un eccellente "orologio dinamico" anche per ammassi giovani e di età intermedia
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