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Modificazioni stagionali dell'ultra struttura della ghiandola androgenica del gambero Aristaeomorpha foliacea
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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 histochemical and ultrastructural study of oogenesis of Aristaeomorpha foliacea (Risso, 1827)
No full textOvaries from mature giant red shrimp Aristaeomorpha foliacea were investigated histochemically and ultrastructurally.
Four growing stages of the oocytes were distinguished: premeiosis stage, previtellogenetic stage, early
vitellogenic stage and late vitellogenic stage. In addition, occasional resorptive oocytes were found. Oogonia and
premeiotic oocytes were found in germinative zones. Previtellogenic and vitellogenic oocytes were localized in
maturative zones. As vitellogenesis proceeded, oocytes showed a progressive development in the number of lipid
droplets as well as in the extension of RER, constituted of dilated cisternae, uniformely scattered throughout the
cytoplasm. The RER produced yolk granules and a lampbrush-like substance. The latter was released under the oolemma
and constituted a characteristic cortical zone. The oolemma did not develop microvilli or micropinocytotic
vesicles to incorporate yolk precursors. Thus, the protein yolk appeared to be of endogenous origin. Few somatic
cells were found around the oocytes, but they never gave place to a continuous epithelial layer around oocytes, thus
it is not possible to speak of ovarian follicle. The cytoplasm of these mesodermal-oocyte associated cells (MOAC)
was characterized by a typical steroidogenic apparatus. Few resorptive immature oocytes were found inside late
vitellogenic oocytes. Since the ovaries were packed with late vitellogenic oocytes and the few immature oocytes
were hardly detectable, oocyte maturation occurred in a synchronous way
IMMUNOHISTCHEMICAL EVIDENCE OF SEASONAL CHANGES OF GONADOTROPES IN MALE RUIN LIZARD(PODARCIS SICULA CAMPESTRIS DE BETTA)
No full textTThe pars distalis from the pituitary gland of adult male ruin lizards (Podarcis sicula campestris De Betta), captured during the reproductive period (May and June), was studied immunohistochemically using specific antibodies against hFSHβ, hLHβ and oLHβ with the avidin-biotin-peroxidase complex (ABC) procedure to determine the localization of both gonadotropins The immunostaining with anti-hFSHβ and anti-hLHβ allowed identification of morphologically distinct FSH containing cells and LH containing cells, whereas anti-oLHβ serum showed cross-reactivity with cells immunostained with the anti-hFSHβ and anti-hLHβ sera. The gonadotropic cells took up approximatively 10.5% of the area of the pars distalis: 10% was positive for FSH, whereas only 0.5% was positive for LH. The FSH cells were distributed throughout the pars distalis, whereas the LH cells were only located in the rostral region. Double-immunostaining procedure did not reveal cells containing both gonadotropic hormones. The findings indicate that FSH and LH are produced in separate pituitary cells
Influence of environmental temperature and humidity on cashmere traits in goats reared in southern Italy
No full textVariations 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
An ultrastructural and histochemical study of the germinal cells contained in hemispermatophores of males of the Aristaeomorpha foliacea (Risso, 1827)
No full textThe ultrastructure and the oligosaccharide sequence of glycoconjugates of spermatozoa contained in the
hemispermatophores of males Aristaeomorpha foliacea collected during the main mating and reproductive
periods have been investigated. The hemispermatophores from eleven specimens were packed with typical
round-shaped spermatozoa (max ø 3.8±0.03 lm), characterised by an electron-lucent nucleus not separated
by the nuclear envelope from the thin electron-dense peripheral band of the cytoplasm containing
small vesicles and large mitochondria. Hemispermatophores from two out of eight specimens collected in
April contained few typical spermatozoa, whereas they were filled with roundish large germinal cells (max ø
5.74±0.16 lm) showing a filamentous chromatin in the nuclear region and the cytoplasm rim rich in large
vesicles and myelin-like bodies. These cells were considered as non-mature germ cells, and consequently we
defined their hemispermatophores as ‘‘immature’’. The lectin histochemistry showed differences in the
glycoconjugate composition between germ cells contained in immature hemispermatophores and spermatozoa.
The former had N-linked oligosaccharides containing a-D-Man and internal b-D-GlcNAc (Con A
and KOH-sialidase-WGA affinity) as well as terminal NeuAca2,6Gal/GalNAc and NeuAca2,3Galb1,
4-GlcNAc (SNA and MAA binding). Spermatozoa from mature hemispermatophores also displayed Olinked
oligosaccharides which terminated with b-D-Gal(1–3)-GalNAc dimer (PNA binding) and aGalNAc
(HPA reactivity) in the cytoplasm and with sialic acid linked to b-D-Gal(1–3)-GalNAc (KOH-sialidase-
PNA procedure) in the nucleus. The extracellular matrix in immature hemispermatophores displayed both
N- and O-linked glycoconjugates, whereas it contained only O-linked oligosaccharides in mature ones.
Although the number of specimens examined is low, this study should indicate that the presence of
hemispermatophores in the terminal ampullae of male A. foliacea and of joined hemipetasmas is not
synonymous with maturity
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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