1,720,964 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Parvalbumin positive basket terminals in layer II of the rat medial entorhinal cortex : postnatal development studied by immuno-electron microscopy
No full textLayer II (LII) of the adult medial entorhinal cortex (MEC) is highly involved in making up animals’ sense of space, and the intrinsic wiring of this network is thought to underlie the very specific firing patterns of its constituent cells. A key component of this network is the parvalbumin positive (PV+) basket cell, which provides rapid inhibition of local principal cells by targeting their perisomatic region, thus making them intimately involved in regulating the spatial codes of these cells. Also, PV+ basket cells target other interneurons in the local network. Because information about how these connections are refined is scarce, the current study was undertaken to investigate the ultrastructural and cytochemical development of the local output from LII PV+ basket cells. After establishing satisfactory protocols, brains from rats of postnatal day (P) 10, P15 and P30 were immunostained for PV and investigated at the light- and electron microscopic level. The results show that while PV+ cells are already abundant in LII of the MEC at P10, their local connectivity changes considerably over the next couple of weeks. First, the density of PV+ somatic terminals increases significantly between P10 and P15, but then decreases from P15 to P30. Secondly, the boutons themselves change in several respects: their size displays a U shaped trend across age groups; in terms of shape, they get more ellipsoid after P10; and the number of mitochondria increases significantly after P15. The extensive maturation of these features thus mainly occurs between P15 and P30. These results indicate that PV+ boutons in LII of the developing rat MEC undergo periods of overshoot and pruning, with concurrent strengthening of remaining terminals during the latter phase
Parvalbumin positive basket terminals in layer II of the rat medial entorhinal cortex : postnatal development studied by immuno-electron microscopy
No full textLayer II (LII) of the adult medial entorhinal cortex (MEC) is highly involved in making up animals’ sense of space, and the intrinsic wiring of this network is thought to underlie the very specific firing patterns of its constituent cells. A key component of this network is the parvalbumin positive (PV+) basket cell, which provides rapid inhibition of local principal cells by targeting their perisomatic region, thus making them intimately involved in regulating the spatial codes of these cells. Also, PV+ basket cells target other interneurons in the local network. Because information about how these connections are refined is scarce, the current study was undertaken to investigate the ultrastructural and cytochemical development of the local output from LII PV+ basket cells. After establishing satisfactory protocols, brains from rats of postnatal day (P) 10, P15 and P30 were immunostained for PV and investigated at the light- and electron microscopic level. The results show that while PV+ cells are already abundant in LII of the MEC at P10, their local connectivity changes considerably over the next couple of weeks. First, the density of PV+ somatic terminals increases significantly between P10 and P15, but then decreases from P15 to P30. Secondly, the boutons themselves change in several respects: their size displays a U shaped trend across age groups; in terms of shape, they get more ellipsoid after P10; and the number of mitochondria increases significantly after P15. The extensive maturation of these features thus mainly occurs between P15 and P30. These results indicate that PV+ boutons in LII of the developing rat MEC undergo periods of overshoot and pruning, with concurrent strengthening of remaining terminals during the latter phase
Variations on the Author
Get PDF“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
Get PDFWe 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
Regional changes in parvalbumin and calbindin expression in fear memory circuits of the developing mouse brain
Get PDFUttrykt i nevroner og vidt distribuert i den voksne musehjernen finner vi kalsiumbindende proteiner. Gjennom utvikling bidrar kalsiumbindende proteiner som parvalbumin og calbindin til modningen av nevrale nettverk som ligger til grunn for en rekke funksjoner, inkludert fryktminneprosesser. Tidligere forskningsfunn konkluderte med at et redusert nivå av disse bindende proteinene kan føre til nevrodegenerative sykdommer og videre være involvert i nevroutviklingsforstyrrelser som angst. Ettersom de fleste studier kun fokuserer på en eller få hjerneregioner er informasjon om antall og tetthetsfordeling av disse kalsiumbindende proteinene i den utviklende musehjernen fragmentert. For å gi en mer omfattende oversikt over mengden og fordeling av kalsiumbindende proteiner i musehjernen, har vi laget en betydelig samling av mer enn 2500 mikroskopiske bilder. Disse bildene viser utviklingsmønsteret til parvalbumin og calbindin positive nevroner, fra musehjerner i alderen 9, 14, 21 og 35 dager. Dette prosjektet gir en analyse fokusert på nettverket som er assosiert med fryktminne, bestående av prelimbisk område, infralimbisk område og basolateral amygdala. Resultatene viser økt nivå av parvalbumin positive nevroner gjennom utvikling mens calbindin nivåer synker. Den største forskjellen ble sett i basolateral amygdala, som indikerer at disse kalsiumbindende proteinene spiller en avgjørende rolle i fryktminneprosesser under utvikling. All data innhentet i dette prosjektet deles offentlig gjennom forskningsinfrastrukturen EBRAINS, som gjør det mulig for forskere å undersøke videre regionale endringer i hjernens arkitektur gjennom utvikling.Calcium-binding proteins expressed in neurons are widely distributed across the adult mouse brain. Through development, calcium-binding proteins such as parvalbumin and calbindin contribute to the maturation of neural networks underlying a range of functions such as fear memory processes. Previous research findings concluded that a decreased level of these binding proteins may result in neurodegeneration and further be involved in neurodevelopmental disorders such as anxiety. Information on the number and density distribution of these binding proteins in the developing mice brain are fragmented, as most studies focus only on one or few brain regions. To provide a more comprehensive overview of the amount and spatial distribution of calcium-binding proteins in the mouse brain, we have created a comprehensive collection of more than 2500 microscopic images. These images illustrate the developmental pattern of parvalbumin and calbindin positive neurons, sampled from the brains of mice aged 9, 14, 21, and 35 days. To demonstrate how this material can be used, the present project provides an analysis focused on areas associated with fear memory networks including prelimbic area, infralimbic area and basolateral amygdala. Our results indicate that parvalbumin levels increase through development while calbindin levels decrease. The largest difference was seen in basolateral amygdala indicating that these binding proteins play a crucial role in fear memory processes during development. All data resulting from this project are publicly shared through the EBRAINS research infrastructure, allowing researchers to further investigate regional changes in brain architecture through development across the entire brain
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
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