1,720,965 research outputs found
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
Alternative matrices for cortisol measurement in fish.
No full textPlasma cortisol is the most commonly used indicator
of stress in fish but, as the blood sampling procedure
itself can be a source of stress, it would be helpful to
measure cortisol using less invasive matrices. It is
also necessary to find alternative matrices as stress
indicators in dead fish inwhich blood sampling is impossible.
In the present study, we investigated transport
stress in three aquaculture species, European
sea bass (Dicentrarchus labrax L.), common carp (Cyprinus
carpio L.) and rainbow trout (Oncorhynchus
mykiss Walbaum), by cortisol determination (radioimmunoassay) in plasma and other matrices (skin
mucus, gut content, lateral muscle and caudal fin).
Cortisol signi¢cantly increased after transport in all
species and matrices, except in the sea bass gut content,
where it remained unchanged. The three species
responded to transport stress by producing
di¡erent cortisol levels. In conclusion, the significant
correlation found between plasma cortisol and most
of the other matrices opens up the possibility of using
them to evaluate stress in fish: mucus sampling is a
less invasive method than blood sampling, and in addition
to muscle and fin sampling, it can be used in postmortem fish
Sex steroids in Tapes philippinarum (Adams and Reeve 1850) during gametogenic cycle: Preliminary results
No full textIt is well known that a wide variety of endocrine-disrupting chemicals (EDCs) (e.g. organotin compounds, heavy metals, herbicides, xenoestrogen compounds) can induce endocrine alterations in aquatic invertebrates, often causing reproductive disorders. Although these phenomena are of great concern, mostly in coastal and estuarine environments, few data are available about the mechanism of action of EDCs, mainly due to lack of knowledge about the invertebrate endocrine system. To understand the possible mechanism of action of EDCs better, the presence and patterns of variation of sexual steroids, progesterone, testosterone and 17β-estradiol were measured in the whole body of the clam Tapes philippinarum by specific and opportunely validated microtitre radioimmunoassays (RIAs). Female steroid concentrations showed similar trends, with higher values during spawning and lower ones in post-spawning and gametogenesis periods. Conversely, in males, sexual steroids varied over the year: progesterone remained unchanged, with values similar to those of females in gametogenesis, whereas testosterone and 17β-estradiol showed a significant decrease during gametogenesis only. Seasonal variations in clam steroid levels may reflect their role in modulating reproduction. All hormones were unexpectedly high in the resting/early developing stage, during which gonadal tissue is scarce, indicating that digestive gland may have a biosynthetic steroid capacity or accumulation. Although these results are preliminary, evaluation of sexual steroids in T. philippinarum during the gametogenic cycle represent the first step for future research aimed at understanding the physiological role of these hormones and their potential interaction with EDCs
Welfare and quality of farmed trout fed high plant protein diets. 1. Growth performance and quality traits.
No full textThis study was performed to evaluate the effects of high levels of inclusion of plant protein sources to replace fish
meal in rainbow trout (O. mykiss) diets on growth performance and quality characteristics. Two isoproteic (44.8%)
and isolipidic (19.6%) extruded diets were fed to eight groups of trout (IBW 106.6g) for 103 days. Diet FM, containing
only fish meal as protein source, was used as control treatment and compared to diet PV80, where a plant
protein mix (pea protein concentrate and wheat gluten) was included to replace 80% of fish meal protein. Growth
performance (FBW: 318.5g; SGR: 1.06%) and feed to gain ratio (0.79) of the fish were not affected by dietary treatment
(p>0.05). Dry matter and protein ADCs, measured in vivo after stripping, resulted higher in fish fed the high
vegetable protein diet relative to the fish meal one (p<0.05). Trout fed diet PV80 were characterised by higher agility
index (2.02 vs 1.72, p<0.05), carcass yield (91.95 vs 91.18%, p<0.05), lower hepatosomatic index (0.74 vs 1.07%,
p<0.05) and viscerosomatic index (8.04 vs 8.82%, p<0.05) but higher mesenteric fat index (3.08 vs 2.88%, p<0.05)
relative to FM fed trout. No significant effect was observed in terms of fillet yield (59.28 vs 6.41%, p<0.05). Feeding
diet PV80 resulted in a significant reduction of fillet pH 48h post mortem (5.56 vs 6.44, p<0.05) while no reduction
was observed in fillet of trout fed the FM diet (6.56, p>0.05). Higher dry matter (28.2 vs 26.8g/100g, p<0.01) and
hydroxyproline (0.79 vs 1.31mg/g, p<0.01) content as a measure of total collagen, was observed in fillets of trout fed
PV80 diet relative to the control ones. According to these data, also post mortem firmness measured by the Shear
force of raw muscle resulted higher in fish fed the plant protein based diet (4.06 vs 3.30N, p<0.05). The firmness
reduction observed 48h post mortem (4.24 vs 2.95N, p<0.05) resulted not affected by the dietary treatment.
In summary, data show that even if the growth performance of rainbow trout fed a diet in which fish meal was
largely replaced by high quality plant proteins resulted similar, some major quality traits such as dressing out, fillet
composition and texture can be significantly affected by dietary treatment
POSTPARTUM PROGESTERONE PROFILES AND REPRODUCTIVE PERFORMANCES OF DAIRY COWS TREATED WITH GnRH OR PROGESTERONE
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