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Modificazioni dei componenti strutturali del nucleo di epatociti durante il risveglio dall'ibernazione: uno studio in vitro
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MEASUREMENTS, ZYMOGRAPHIC ANALYSIS, AND CHARACTERIZATION OF MATRIX METALLOPROTEINASE-2 AND -9 IN HEALTHY HUMAN UMBILICAL CORD BLOOD
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DIFFERENTIAL USE OF GRANULE RELEASE, FAS LIGAND AND TRAIL CYTOTOXIC MECHANISM BY MATURE AND IMMATURE NK CELLS
No full textDisassembly of nuclear bodies during arousal from hibernation: an in vitro study
No full textIn previous studies we demonstrated that during hibernation cell nuclei contain structural constituents usually absent in euthermia. The rapid disappearance of such nuclear bodies upon arousal makes very difficult the in vivo investigation of the disassembly process, which could clarify their functions in nuclear metabolism in the hibernator. In the present study we subjected liver samples taken from hibernating edible dormice (Glis glis) to different in vitro experimental conditions: at 4°C, to preserve the hypothermic state of the hibernating organism; at 37°C, to simulate the drastic increase in body temperature occurring during arousal; at 37°C, in culture medium containing 10-5 M delta opioid D-Ala2-D-Leu5 enkephalin, which mimics the activity of the hibernation induction trigger in hibernators. Electron microscopic analysis of hepatocyte nuclei at increasing incubation times revealed the subsequent steps of disassembly of coiled bodies, amorphous bodies and fibrogranular material, the unusual structural constituents accumulating during hibernation in these nuclei. We demonstrated that: (1) a temperature of 37°C induces the disappearance of all nuclear bodies typical of hibernation in a few minutes; (2) both low temperature and hibernation-triggering opioid are able to slow down, although to different extents, the process of disassembly of nuclear bodies; (3) the fibro-granular material rapidly disappears during the early phases of incubation; while (4) coiled bodies and amorphous bodies progressively disassemble as fibrous material. Our results support previous hypotheses based on in vivo observations about a possible role for coiled bodies, amorphous bodies and fibro-granular material as storage/assembly sites of molecules needed for the rapid and massive resumption of transcriptional and post-transcriptional activities upon arousal and suggest a strict correlation between the dynamics and metabolic rate of nuclear bodies
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
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