1,721,030 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
EFFECTS OF ACUSTIC STRESS ON BIOCHEMICAL AND MOBILITY PARAMETERS AND BEHAVIOUR IN THE CRAYFISH, CHERAX DESTRUCTOR
No full textBiological responses to high-frequency sound in a freshwater crayfish, Cherax quadricarinatus
No full textAnthropogenic noise is recognised as an important environmental stressor that can have longterm negative consequences on species. In recent years, there has been increasing attention to the potential negative impact of noise pollution on species, with great concern for the importance of impacts on aquatic animal life.
This study examined the effects of acoustic stress on the biochemical parameters of the freshwater crayfish Cherax quadricarinatus. The experiment was conducted in a tank equipped with an audio and video recording system using ten groups (five control and five test) of three adult crayfish (30 animals in total). The
animals in the test group were exposed to acoustic signals [a linear sweep from 10 to 200 kHz lasting 1 s, with a sound pressure level between 138 and 157 dBrms (re 1lParms)] for 45 minutes. Biochemical parameters such as pH, osmolarity, protein concentration and enzyme activities (alkaline phosphatase, esterase and peroxidase) were evaluated. Enzyme activities show significant changes, with significantly lower values in stressed animals. These results suggest that high-frequency stimuli induce a physiological stress response, thus suggesting
that acoustic stress may have physiological effects on the species
Behavioural and biochemical stress responses of Cherax quadricarinatus after exposure to acoustic signal in tank
No full textAnthropogenic sound is recognized as a major environmental stressor that, in the long term, can have negative consequences on species. In recent years, there has been growing attention to the potential negative impact of noise pollution on species, with great concern about the significance of impacts on aquatic animal life. This study examined the effects of acoustic stress on the behavior and biochemical parameters of the freshwater shrimp Cherax quadricarinatus.
The experiment was conducted in a tank equipped with an audio and video recording system using ten groups (five control and five test) of three adult shrimp (30 animals in total). Animals in the test group were exposed to acoustic signals [a linear sweep from 1 to 20 kHz lasting 1 s, with a sound pressure level between 138 and 157 dBrms (re 1lParms)] for 45 minutes. Behavioral parameters such as, total acoustic signals emitted, movement velocity, angular velocity, distance moved, no. of fights, encounters, tail flip and biochemical parameters such as pH, osmolarity, protein concentration and enzyme activities (alkaline phosphatase, esterase and peroxidase) were evaluated. Exposure to the acoustic signal produced significant changes on the specie's total acoustic signals emitted and no. of fights. Enzyme activities show significant changes, with significantly lower values in stressed animals. These results suggest that high-frequency stimuli induce both a behavioural and physiological response, thus suggesting that acoustic stress may have an effect on the species
Collective locomotion of human cells, woundh healing and their control by extracts and isolated compounds from marine ivertebrates
Full text linkThe collective migration of cells is a complex integrated process that represents a common theme joining morphogenesis, tissue regeneration, and tumor biology. It is known that a remarkable amount of secondary metabolites produced by aquatic invertebrates displays active pharmacological properties against a variety of diseases. The aim of this review is to pick up selected studies that report the extraction and identification of crude extracts or isolated
compounds that exert a modulatory effect on collective cell locomotion and/or skin tissue reconstitution and recapitulate the molecular, biochemical, and/or physiological aspects, where available, which are associated to the substances under examination, grouping the producing species according to their taxonomic hierarchy. Taken all of the collected data into account, marine invertebrates emerge as a still poorly-exploited valuable resource of natural products that may significantly improve the process of skin regeneration and restrain tumor cell migration, as documented by in vitro and in vivo studies. Therefore, the identification of the most promising invertebrate-derived extracts/molecules for the utilization as new targets for biomedical translation merits further and more detailed investigations
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
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