1,720,985 research outputs found
Increased by-catch rates in the Gulf of Taranto, Italy, in 20 years: A clue about sea turtle population trends?
No full textInformation on sea turtle population trends is fundamental to assess the population status and the effects of conservation measures, and is considered a priority for sea turtle conservation. To provide insights on trends at sea, we compared by-catch data from long-liners fishing in the Gulf of Taranto in 2 periods: 1978-1979 and 1998-2003. A total of 653 loggerhead sea turtles (Caretta caretta) were captured in 2679 fishing sets targeting swordfish and albacore tuna; catch rates were significantly higher in the second period, while average turtle size was smaller. Although possible effects of sampling techniques cannot be excluded, a negative trend in the number of turtles in the study area and period was unlikely. © 2012 Chelonian Research Foundation
The first spontaneous spawning of red drum Sciaenops ocellatus L. in Europe: broodstock management and early larval stages
Get PDFThe present paper reports a research on reproductive parameters and larval rearing of red drum (Sciaenops ocellatus) maintained in captivity for the first time in Europe. Red drum juveniles were obtained from United States in the late 90s. In early January 2013, 40 in total male and female red drums ranging from 34 to 47 cm in length were held in a 25 m3 rectangular tank with a closed recirculating system with a water flow of 6000 L/h, located in Lesina (FG) fish farm (Southern Italy). Water temperature and salinity ranged between 21.0 and 28.8°C and from 25 to 27 g/L respectively. The fish were fed commercial feed pellet (46% protein) at 1.1% of body weight daily. Sexual maturation occurred during the natural breeding season of red drum. Approximately 43 spawns were recorded by the end of July and continuing to mid-September, with mean number of 66.5 millions of eggs collected overall on spawn period. Batch fecundity (3.325*106 ova per female) and relative fecundity (361.41 ova/g body weight) were calculated. Fertilisation rate was 30 to 80%. Larvae were hatched at a mean total length of 2.40±0.33 mm and showed a gradual increase in size of approximately 0.378 mm/day for the first 40 day after hatching (DAH). Cannibalism was observed as larger larvae preyed on smaller ones; to limit the phenomenon red drum population was selected for size at 35 DAH. Reliable information on fecundity and larval stage is essential for encouraging Sciaenops ocellatus farming also in Mediterranean countries
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
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
Histological investigation on the ovarian cycle of the bluefin tuna in the western and central Mediterranean
No full textThe histological analysis of eastern Atlantic bluefin tuna Thunnus thynnus ovaries caught from February to September 1999-2000, made it possible to distinguish the presence of seven oocyte developmental stages and allowed the characterization of six time-dependent ovary maturity stages. The ovaries of mature (fork length, L F ≥ 110 cm) bluefin tuna were non-active from August (spent period) to March (quiescent period) when they contained only perinucleolarstage oocytes. Ovary development started in April to early May (recrudescent period) with the appearance of oocytes at the lipid stage. Vitellogenesis appeared in mid-May (ripening period) and post-vitellogenesis occurred in late May to mid-June (pre-spawning period). In late June to early July, hydrated oocytes, a sign of imminent spawning, were found only in specimens caught in Balearic waters. Females ranging between 100 and 110 cm L F, captured during the recrudescent and ripening periods, had the largest oocytes at the lipid stage, most of which were degenerating. An extensive vitellogenic atresia was observed in the ovaries of five females caught during the spawning period in non-spawning areas
Differential lectin binding patterns in the oviductal ampulla of the horse during oestrus
Get PDFWe investigated the oligosaccharide sequence of glycoconjugates,
mainly sialoglycoconjugates, in the horse oviductal
ampulla during oestrus by means of lectin and pre-lectin
methods such as the KOH-neuraminidase procedure to
remove sialic acid residues and incubation withN-glycosidase
F to cleaveN-linked glycans. Ciliated cells displayedN-linked
oligosaccharides throughout the cytoplasm. The cilia
glycocalyx expressed bothN- andO-linked (mucin-type)
oligosaccharides, both showing a high variety of terminal
sequences. In the most non-ciliated cells, the whole cytoplasm
containedN-linked oligosaccharides with terminal
αGal as well as mucin-type glycans with terminal Forssman
pentasaccharides. In a few scattered non-ciliated cells, the
whole cytoplasm displayed sialylatedN-linked oligosaccharides
with terminal Neu5Ac-GalNAc andO-linked glycans terminating
with neutral and/or αGalNAc, Neu5Acα2,6Gal/
GalNAc, Neu5AcGalβ1,3GalNAc. Supra-nuclear granules,
probably Golgi zones, of non-ciliated cells showed mainlyO-linked
glycans rich in sialic acid residues. The luminal surface
of non-ciliated cells showedN-linked oligosaccharides,
containing terminal/internal αMan/αGlc, βGlcNAc and terminal
αGal, as well as mucin-type oligosaccharides terminating
with a large variety of either neutral saccharides or
sialylated sequences. Apical protrusions containingO-linked
oligosaccharides with terminal Forssman pentasaccharide,
Neu5Ac-Galβ1,4GlcNAc, Neu5Ac-GalNAc were seen in nonciliated
cells scattered along the epithelium. These findings
show the presence of sialoglycoconjugates in the oviductal
ampulla epithelium of the mare and the existence of different
lectin binding profiles between ciliated and non-ciliated
(secretory) cells, as well as the presence of non-ciliated cell
sub-types which might determine functional differences
along the ampullary epithelium of mare oviduct
Distribution of sialoglycoconjugates in the oviductal isthmus of the horse during anoestrus, oestrus and pregnancy: a lectin histochemistry study
Get PDFThe distribution of sialic acid residues as well as other glycosidic
sugars has been investigated in the horse oviductal isthmus
during anoestrus, oestrus and pregnancy by means of
lectin and pre-lectin methods. Ciliated cells and non-ciliated
(secretory) cells exhibited different lectin binding profiles
that were found to change during the investigated stages.
Ciliated cells did not show any reactivity in the basal cytoplasm,
while the supra-nuclear cytoplasm displayed a few of
oligosaccharides with terminal and internal amannose (Man)
and/or aglucose (Glc) during oestrus and pregnancy and a
moderate presence of oligosaccharides terminating in afucose
(Fuc) during oestrus; cilia exhibited a more complex glycoconjugate
pattern for the presence of oligosaccharides terminating
in N-acetylgalactosamine (GalNAc), GalNAca1,3
GalNAca1,3galactose(Gal)b1,4Galb1,4N-acetylglucosamine(
GlcNAc), Fuc, sialic acid (Neu5Ac)-aGalNAc belonging
or not to the GalNAca1,3GalNAca1,3 Galb1,4 Galb1,
4GlcNAc sequence, and.aGalNAc and Neu5Aca 2,6Gal/GalNAc
increased during oestrus. Cilia displayed terminal Galb1,3
GalNAc in pregnancy, terminal aGal in anoestrus and pregnancy
and terminal or internal D-GlcNAc during anoestrus
and pregnancy, respectively. The whole cytoplasm of non-ciliated
cells showed oligosaccharides terminating with
aGalNAc, Neu5Aca2,6Gal/GalNAc, Neu5Ac GalNAca
1,3GalNAca1,3Galb1,4Galb1,4GlcNAc during the investigated
stages, as well as GlcNAc in anoestrus and pregnancy.
The supra-nuclear zone of non-ciliated cells exhibited
oligosaccharides with terminal Galb1,4GlcNAc and internal
Man during oestrus and pregnancy as well as terminal aGal
and Fuc in oestrus and Neu5Ac-Galb1,3GalNAc in pregnancy.
The luminal surface of non-ciliated cells showed glycans
terminating with aGalNAc and/or Neu5Ac GalNAca1,3
GalNAca1,3Galb1,4Galb1,4GlcNAc in all specimens, oligosaccharides
with terminal Galb1,4GlcNAc and internal Man during
oestrus and pregnancy, Neu5Ac a2,6Gal/GalNAc in
anoestrus and oestrus, and glycans terminating with
Galb1,3GalNAc, Neu5A aca2,3 Galb1, 4GlcNac, Neu5ac-
Galb1,3GalNAc, Neu5Ac-Galb1,4 GlcNAc in pregnancy.
These findings show the presence of sialoglycoconjugates in
the oviductal isthmus of the mare as well as the existence of
great modifications in the glycoconjugates linked to different
physiological conditions
Autonomic and sensitive somatic innervation of the ostrich elbow and knee joints articular capsule
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