1,721,122 research outputs found
PRESYNAPTIC FACILITATION OF GLYCINERGIC mIPSC IS REDUCED IN MICE LACKING alpha 3 GLYCINE RECEPTOR SUBUNITS
No full textGlycinergic neurons provide an important mechanism to control excitation of motoneurons in the brainstem and a reduction or loss of glycinergic inhibition can be deleterious by leading to hyperexcitation such as in hyperekplexia or neurodegeneration and neuronal death as in amyotrophic lateral sclerosis (ALS). Second messenger systems that change cyclic AMP and lead to phosphorylation of the alpha 3 subunit of the glycine receptor (GlyR alpha 3) have been shown to be potent modulators of synaptic inhibition in the spinal cord and brain stem. In this study we analyzed the role of GlyR alpha 3 in synaptic inhibition to the hypoglossal nucleus using Glra3 (the gene encoding the glycine receptor alpha 3 subunit) knockout mice. We observed that baseline glycinergic synaptic transmission to nucleus of hypoglossal motoneurons is rather normal in Glra3 knockout mice. Interestingly, we found that the modulation of synaptic transmission by cAMP-mediated pathways appeared to be reduced in Glra3 knockout mice. In the second postnatal week the forskolin-induced increase of miniature inhibitory postsynaptic potential (mIPSC) frequency was significantly larger in control as compared to Glra3 knockout mice suggesting that presynaptic glycine release in the hypoglossal nucleus is partially depending on GlyR alpha 3. (C) 2016 IBRO. Published by Elsevier Ltd. All rights reserved.Deutsche Forschungsgemeinschaft [Hu797/7-1, Hu797/8-1
A potential presynaptic role of Glra3 in regulation of glycinergic synaptic inhibition to hypoglossal motoneurons
No full textA potential presynaptic role of Glra3 in regulation of glycinergic synaptic inhibition to hypoglossal motoneurons
No full textViscosity of alkaline basalts at high pressure: constraints on the pre-eruptive system of Campi Flegrei (Italy)
No full textThe Campi Flegrei Volcanic District (CFVD) includes the Campi Flegrei caldera, the islands of Procida
and Ischia, and it is among the most dangerous volcanic systems of the world. The volcanic activity that has
characterized the recent eruptive history of the CFVD includes both effusive and hydromagmatic eruptions
that resulted in a variety of igneous products from alkaline basalts to trachytes. Among CFVD products,
basaltic lava fragments dispersed in the hydromagmatic tuff of the Solchiaro eruption (Procida island) result
to be representative of near-primary melts on the basis of their geochemical and isotopical signatures. The
knowledge of the viscosity of primitive magmas at high pressure and temperature is needed to model their
mobility and ascent rate. These variables allow us to predict the potential volcanic activity at surface. In
this study, we investigated the viscosity and melt structure of APR16 alkaline basalt, a lava fragment of
the Solchiaro eruption. The anhydrous glassy starting material was prepared at Bayerisches Geoinstitut by
using a gas-mixing furnace, by melting the APR16 rock powder at 1400 °C for 15 minutes at atmospheric
pressure and oxygen fugacity buffered at Nickel-Nickel Oxide level using a CO/CO2 gas mixture. Experiments
were performed at pressure between 0.7 and 2.3 GPa and temperatures of 1200 °C-1700 °C using the Paris-
Edinburgh press combined with synchrotron X-ray technique at beamline 16-BM-B (HPCAT) of the Advanced
Photon Source (Argonne National Laboratory, Illinois, USA). Viscosity measurements were conducted with
the falling sphere technique. The falling velocity of the platinum probing sphere was measured at each run
by ultrafast X-ray radiography using a high-speed camera at 500 frames per second as recording rate. The
viscosity was, then, calculated from the Stokes’ equation including the correction factors for the effect of the
wall and the end effect (Kono et al., 2014). Structural measurements of the liquid at 1700 °C and 2.3 GPa were
also performed using multi-angle (2θ angle between 3° to 35°) energy dispersive X-ray diffraction technique.
Preliminary results show the viscosity increasing from 0.1 to 1 Pa·s as pressure decreases from which an
increase in the polymerization during decompression can be inferred. Our results are used to constrain the
mobility and ascent velocity of primitive alkaline basalts considered to be parental magmas at Campi Flegrei
with important implications for the potential volcanic hazard of the area.
Kono, Y., Park, C., Kenney-Benson, C., Shen, G. & Wang, Y. (2014): Toward comprehensive studies of liquids at high
pressures and high temperatures: Combined structure, elastic wave velocity, and viscosity measurements in the Paris-
Edinburgh cell. Phys. Earth Planet. Inter., 228, 269-280
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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