1,720,957 research outputs found
High-resolution analysis of bound Ca 2+ in neurons and synapses
No full textCalcium (Ca 2+ ) is a well-known second messenger in all cells, and is especially relevant for neuronal activity. Neuronal Ca 2+ is found in different forms, with a minority being freely soluble in the cell and more than 99% being bound to proteins. Free Ca 2+ has received much attention over the last few decades, but protein-bound Ca 2+ has been difficult to analyze. Here, we introduce correlative fluorescence and nanoscale secondary ion mass spectrometry imaging as a tool to describe bound Ca 2+ . As expected, bound Ca 2+ is ubiquitous. It does not correlate to free Ca 2+ dynamics at the whole-neuron level, but does correlate significantly to the intensity of markers for GABAergic pre-synapse and glutamatergic post-synapses. In contrast, a negative correlation to pre-synaptic activity was observed, with lower levels of bound Ca 2+ observed in the more active synapses. We conclude that bound Ca 2+ may regulate neuronal activity and should receive more attention in the future.Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/50110000165
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
A Versatile Synaptotagmin‐1 Nanobody Provides Perturbation‐Free Live Synaptic Imaging And Low Linkage‐Error in Super‐Resolution Microscopy
No full textAbstract Imaging of living synapses has relied for over two decades on the overexpression of synaptic proteins fused to fluorescent reporters. This strategy alters the stoichiometry of synaptic components and ultimately affects synapse physiology. To overcome these limitations, here a nanobody is presented that binds the calcium sensor synaptotagmin‐1 (NbSyt1). This nanobody functions as an intrabody (iNbSyt1) in living neurons and is minimally invasive, leaving synaptic transmission almost unaffected, as suggested by the crystal structure of the NbSyt1 bound to Synaptotagmin‐1 and by the physiological data. Its single‐domain nature enables the generation of protein‐based fluorescent reporters, as showcased here by measuring spatially localized presynaptic Ca 2+ with a NbSyt1‐ jGCaMP8 chimera. Moreover, the small size of NbSyt1 makes it ideal for various super‐resolution imaging methods. Overall, NbSyt1 is a versatile binder that will enable imaging in cellular and molecular neuroscience with unprecedented precision across multiple spatiotemporal scales.Deutsche Forschungsgemeinschaft https://doi.org/10.13039/501100001659Vinnova https://doi.org/10.13039/501100001858Novo Nordisk Fonden https://doi.org/10.13039/501100009708Vetenskapsrådet https://doi.org/10.13039/501100004359Cancerfonden https://doi.org/10.13039/50110000279
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
