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Modificazioni stagionali della membrana basale dell’epitelio seminifero della lucertola Podarcis sicula Raf
No full textLa membrana basale regola l'attività dell'epitelio seminifero nei vertebrati a riproduzione stagionale.
In questo lavoro vengono illustrati i risultati di indagini istochimiche, immunoistochimiche ed
ultrastrutturali sulla membrana basale del testicolo di Podarcis sicula, in condizioni normali e
sperimentali. Gonadi di maschi adulti di Podarcis s. catturati nel periodo riproduttivo (maggio) e di
crisi estiva (luglio), alcuni trattati con estradiolo, sono stati: 1) fissati in liquido di Stieve, inclusi in
paraffina e le sezioni colorate con ematossilina-eosina, PAS e immunocolorate per la ricerca della
laminina e del collagene IV; 2) fissati in GTA 3%, post-fìssati in OsO4 1%, inclusi in Araldite e le
sezioni ultrafini osservate al TEM. La PAS reazione ha mostrato debole affinità per la membrana
basale in tutti gli esemplari che solo in luglio hanno evidenziato una netta colorazione della laminina,
mentre il collagene IV è stato ben marcato nei testicoli degli esemplari di maggio trattati con estradiolo
e, soprattutto, di luglio (trattati e non). Nel periodo riproduttivo la membrana basale (spessa 200 nm)
ha mostrato aspetto lineare mentre nel periodo di stasi estiva è apparsa notevolmente introflessa e
spessa 300 nm per incremento di ampiezza della lamina tìbroreticolare. Negli esemplari estrogenizzati
di luglio un materiale reti co lo granulare di origine ematica è stato imbrigliato e trattenuto dalla lamina
fibroreticolare. In conclusione, la membrana basale dei tubuli seminiferi di lucertola subisce
modificazioni strutturali e molecolari correlate con l'attività testicolare stagionale e svolge anche un
ruolo di barriera molecolare con compiti di protezione dell'epitelio seminifero
Evidence of regional differences in the lectin histochemistry along the ductus epididymis of the lizard, Podarcis sicula Raf
No full textThe regional difference in the carbohydrate components of the ductus epididymis epithelium of a lizard was delineated
by means of 13 lectins. Basal cells expressed only N-acetylglucosamine (GlcNAc). Throughout the ductus, the secretory
cells showed oligosaccharides with terminal N-acetylneuraminic acid (Neu5Ac)α(2,6)galactose (Gal)/N-acetylgalactosamine
(GalNAc) and internal mannose (Man) and/or glucose (Glc) in the whole cytoplasm, oligosaccharides terminating in
Neu5Acα(2,6)Galβ(1,3)GalNAc, Neu5Acα(2,6)Galβ(1,4)GlcNAc, GalNAc, GlcNAc, and fucose (Fuc) in the supra-nuclear
zone, and also glycans terminating in Neu5Acα(2,3)Galβ(1,4)GlcNAc, Neu5Acα(2,6)Galβ(1,3)GalNAc, Galβ(1,4)GlcNAc
on the luminal surface. In the caput and corpus regions, the supra-nuclear cytoplasm was characterized by terminal
Galβ(1,4)GlcNAc and αGalNAc, the luminal surface by αGalNAc and Gal. The Golgi zone, showing oligosaccharides with
terminal Neu5Acα(2,3)Galβ(1,4)GlcNAc, Neu5Acα(2,6)Galβ(1,3)GalNAc, Neu5Acα(2,6)Galβ(1,4)GlcNAc, and internal
GlcNAc, expressed terminal Galβ(1,4)GlcNAc and αGalNAc in the caput, and terminal βGalNAc in the corpus. The granules
showed all the investigated carbohydrates in their peripheral zone except terminal βGalNAc and Fuc, whereas internal Man/Glc
and terminal Gal were expressed in the central core, and Fuc throughout the ductus, terminal GlcNAc in the caput and corpus,
and terminal αGalNAc only in the corpus
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
Localizzazione immunoistochimica delle cellule a MSH nell’ipofisi di pesce spada (Xiphias gladius L.).
No full textPituitary MSH cels were immunohistochemically localized in the teleost fish Xiphias gladius L. using anti a-MSH polydonal
serum. MSH cells were found mainly in the pars intermedia (PI) and scarsety in the PD. The density of MSH cells showed difference related to sex and size ofspecimens
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
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