3,609 research outputs found

    Activity of nAChRs containing α9 subunits modulates synapse stabilization via bidirectional signaling programs

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    Although the synaptogenic program for cholinergic synapses of the neuromuscular junction is well known, little is known of the identity or dynamic expression patterns of proteins involved in non-neuromuscular nicotinic synapse development. We have previously demonstrated abnormal presynaptic terminal morphology following loss of nicotinic acetylcholine receptor (nAChR) α9 subunit expression in adult cochleae. However, the molecular mechanisms underlying these changes have remained obscure. To better understand synapse formation and the role of cholinergic activity in the synaptogenesis of the inner ear, we exploit the nAChR α9 subunit null mouse. In this mouse, functional acetylcholine (ACh) neurotransmission to the hair cells is completely silenced. Results demonstrate a premature, effusive innervation to the synaptic pole of the outer hair cells in α9 null mice coinciding with delayed expression of cell adhesion proteins during the period of effusive contact. Collapse of the ectopic innervation coincides with an age-related hyperexpression pattern in the null mice. In addition, we document changes in expression of presynaptic vesicle recycling/trafficking machinery in the α9 null mice that suggests a bidirectional information flow between the target of the neural innervation (the hair cells) and the presynaptic terminal that is modified by hair cell nAChR activity. Loss of nAChR activity may alter transcriptional activity, as CREB binding protein expression is decreased coincident with the increased expression of N-Cadherin in the adult α9 null mice. Finally, by using mice expressing the nondesensitizing α9 L90T point mutant nAChR subunit, we show that increased nAChR activity drives synaptic hyperinnervation. © 2009 Wiley Periodicals, Inc.Fil: Murthy, Vidya. Tufts University School of Medicine; EslovaquiaFil: Taranda, Julian. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Tufts University School of Medicine; EslovaquiaFil: Elgoyhen, Ana Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Farmacología; ArgentinaFil: Vetter, Douglas E.. Tufts University School of Medicine; Eslovaqui

    An Empirical Analysis of the Relative Efficiency of Stock and Mutual Savings and Loan Associations

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    Daniel E. Vetter is an Assistant Professor of Finance at Drake University

    Tokolyse bei vorzeitiger Wehentätigkeit

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    Zusammenfassung : Im September 2006 wurde die Leitlinie 015/025 "Medikamentöse Wehenhemmung bei drohender Frühgeburt" (http://www.dggg.de, http://www.awmf-online.de) publiziert. Sie zeigt den Korridor auf, innerhalb dessen die Verwendung von Tokolytika bei vorzeitiger Wehentätigkeit dem derzeitigen Stand der Wissenschaft und der sog. guten klinischen Praxis entspricht. Fenoterol, Atosiban, Indometacin und Nifedipin sind äquieffektiv, unterscheiden sich aber im Nebenwirkungsprofil, Kontraindikationen, Kosten und Zulassung. Erläutert werden die Empfehlungen, zusammengefasst werden die wesentlichen Ziele der medikamentösen Wehenhemmung: Durchführung der Lungenreifeprophylaxe bei drohender Frühgeburt, Schwangerschaftsverlängerung bei vorübergehenden Ursachen vorzeitiger Wehentätigkeit (z.B. Durchführung einer Cerclage, Pyelonephritis) sowie Ermöglichung des Transportes der Schwangeren in ein Perinatalzentru

    Planetary/DOD entry technology flight experiments. Volume 3: Planetary entry flight experiments handbook

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    The environments produced by entry into Jupiter and Saturn atmospheres are summarized. Worst case design environments are identified and the effect of entry angle, type of atmosphere and ballistic coefficient variations are presented. The range of environments experienced during earth entry is parametrically described as a function of initial entry conditions. The sensitivity of these environments to vehicle ballistic coefficient and nose radius is also shown. An elliptical deorbit maneuver strategy is defined in terms of the velocity increment required versus initial entry conditions and apoapsis altitude. Mission time, ground track, and out of plane velocity penalties are also presented. Performance capabilities of typical shuttle launched boosters are described including the initial entry conditions attainable as a function of paylaod mass and apoapsis altitude

    Planetary/DOD entry technology flight experiments. Volume 1: Executive summary

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    The feasibility of using the space shuttle to launch planetary and DoD entry flight experiments was examined. The results of the program are presented in two parts: (1) simulating outer planet environments during an earth entry test, the prediction of Jovian and earth radiative heating dominated environments, mission strategy, booster performance and entry vehicle design, and (2) the DoD entry test needs for the 1980's, the use of the space shuttle to meet these DoD test needs, modifications of test procedures as pertaining to the space shuttle, modifications to the space shuttle to accommodate DoD test missions and the unique capabilities of the space shuttle. The major findings of this program are summarized

    Homophobia, Fundamentalism, and Canadian Tolerance: Enabling Gay Games III in Vancouver

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    Gay Games III were held in Vancouver in August 1990. This paper analyzes the effects of three different moments of homophobic backlash faced by organizers of that event. While quiet institutional homophobia might have been tolerated, public representations of blatant homophobia could be mobilized by the organizers of Gay Games IIII to their advantage. The effects of a hateful campaign paradoxically functioned as an interesting condition of possibility for Gay Games' credibility. I then suggest that the limitations of these liberal strategies were shown up by the fractures within local lesbian and gay communities, demonstrating the weaknesses of accepting tolerance as a limit to the possible.Les troisièmes Jeux Gais ont eu lieu à Vancouver en août 1990. Ce document analyse les effets de trois moments différents du ressac homophobe auquel ont fait face les organisateurs de cet événement. Même si l’homophobie institutionnelle discrète aurait pu être tolérée, les organisateurs de ces jeux ont pu tourner à leur avantage les représentations publiques de l’homophobie flagrante. Les effets d’une campagne de haine ont paradoxalement été favorables à la possibilité de tenir des Jeux Gais crédibles. Je crois donc que les fractures observées dans les communautés lesbienne et gaie locales ont fait ressortir les limites de ces stratégies libérales en démontrant les failles de l’acceptation de la tolérance comme limite du possible

    Rate of population of CO(v) in a CS2/O2 flame

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    The rate of vibrational population of carbon monoxide in a steady CS2/O2 flame has been determined from CO overtone emission. A steady-state analysis indicates that, for a flame, the fifteenth vibrational level has the largest rate of population

    Frequency shift of hyperfine transitions due to blackbody radiation

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    We have performed calculations of the size of the frequency shift induced by a static electric field on the clock transition frequencies of the hyperfine splitting in Yb+, Rb, Cs, Ba+, and Hg+. The calculations are used to find the frequency shifts due to blackbody radiation which are needed for accurate frequency measurements and improvements of the limits on variation of the fine structure constant, alpha. Our result for Cs (delta nu E^2=-2.26 times 10^{-10}Hz/(V/m)^2) is in good agreement with early measurements and ab initio calculations. We present arguments against recent claims that the actual value might be smaller. The difference (approx 10%) is due to the contribution of the continuum spectrum in the sum over intermediate states.Comment: Added discussion of Cs results and reference

    Detection of Composite Delaminations and Broken Solder Joints by a Full-Field Laser Doppler Technique

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    A method for full-field non-contact vibration measurement based on the Michelson Interferometer has been developed and applied to a wide range of components and structures. Unlike other optical techniques such as holography, the vibration imager does not require a specialized laboratory and stable environment, works over a much wider dynamic range,and the vibration time history is available for a more detailed analysis of the structures response. Use of this technique to detect delaminations in graphite/epoxy specimens is explored in this paper. The data was compared with X-ray and ultrasonic methods. The integrity of solder joints in electronic circuit boards has also been studied by this method at the University of Wisconsin, Madison and is also presented in this paper
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