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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
The associative behaviour of silky sharks, Carcharhinus falciformis, with floating objects in the open ocean
Get PDFThe silky shark Carcharhinus falciformis forms the primary elasmobranch
bycatch in tuna purse seine fisheries using fish aggregating devices (FADs)
in all of the world’s tropical oceans. Its life-history traits of slow growth,
late maturation and low fecundity make it vulnerable to over exploitation,
as is apparent from historical bycatch trends. Very little is known about the
associative behaviour of this species with floating objects, information which is
essential in formulating effective mitigation and management measures. This
study aims to address this knowledge gap through the use of various electronic
tagging techniques in conjunction with dietary analysis. Dietary data were
collected from 323 silky sharks incidentally caught at FADs. Approximately
40 percent of the diet consisted of prey associated with FADs while the remaining
60 percent were non-associated species of crustaceans, cephalopods and fishes.
These results suggest that the associative behaviour is not primarily driven
by trophic enhancement, but is likely a combination of predator avoidance,
social interactions and feeding. Fine-scale behavioural data from silky sharks
associated with drifting FADs were collected through the use of acoustic
telemetry techniques. Acoustic tags were implanted into 38 silky sharks (69-
116 cm TL) at eight FADs. FADs were equipped with satellite linked acoustic
receivers and abandoned to drift freely. Presence/absence and swimming
depth data were telemetered via the Iridium satellite system. A total of 300 d of
behavioural data were collected from 20 tagged individuals. Individuals remain
associated with the same FAD for extended periods (min = 2.84 d, max = 30.60
d, mean = 15.69 d). Strong diel patterns were observed in both association and
swimming depth. Typically individuals moved away from FADs after sunset and
return later during the night, then remain closely associated until the following
evening. Vertical behaviour also changed around sunset with sharks using
fairly constant depths, within the upper 25 m, during the day and switching
to rapid vertical movements during the night, with dives in excess of 250 m recoded. Broader scale movement behaviour was investigated using pop-up
archival satellite tags (PSATs). Tags were deployed on 46 silky sharks (86-224.5
cm TL) for a total of 1495 d. Light data were used to calculate geolocation
estimates and reconstruct the sharks’ trajectories. Movement patterns differed
between animals and according to deployment duration. Several extensive
horizontal movements were observed, with an average track length of 3240 km
during an average tag deployment of 44.02 d. Horizontal movement patterns
were found to correlate very closely with drift patterns of FADs. Consequently,
it appears that the movement behaviour of juvenile silky sharks is strongly
influenced by the movement of drifting FADs in this region. Ghost fishing
of silky sharks through entanglement in FADs was also investigated using
data derived from PSATs as well as underwater visual censuses. Thirteen per
cent of the tagged sharks became entangled in FADs and entangled sharks
were observed in 35 percent of the 51 FADs surveyed. Using this information in
conjunction with estimated time that sharks remained entangled in the FAD
(from depth data from PSATs), and scaling up according to estimates of FAD
numbers, it was found that between 480 000 and 960 000 silky sharks are
killed annually in this manner in the Indian Ocean. Subsequent management
measures in this region prevent the deployment of FADs with netting that could
lead to entanglement. Overall, floating objects appear to play a significant role
in the juvenile life stages of silky sharks in this region. While their association
with floating objects is clearly advantageous in an evolutionary sense, under
current tuna fishery trends, this behaviour is certainly detrimental for the
population
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
Movements of sub-adult sicklefin lemon sharks Negaprion acutidens in a remote Indian Ocean atoll
Get PDFThe sicklefin lemon shark Negaprion acutidens is a large-bodied (> 3m) coastal shark
species, widely distributed in tropical and sub-tropical Indo-Pacific waters. Despite its
large size and wide distribution, very little is known about its movement behaviour
throughout ontogeny. The primary aim of this thesis was to gain an understanding of the
movements of sub-adult N. acutidens, in and around the St. Joseph Atoll, Republic of
Seychelles, to facilitate the effective conservation of this vulnerable species. A total of
22 sharks (139 – 202 cm TL) were equipped with coded acoustic transmitters and
passively monitored using moored acoustic receivers for a period of 20 month from
March 2009 to October 2010.
The use of passive acoustic telemetry arrays to study behavioural ecology has increased
in popularity in recent years and been successfully applied to study a host of teleost and
elasmobranch species in a diversity of habitats, ranging from sheltered estuaries to the
offshore pelagic environment. However, the practicalities of designing an effective
network of receivers to optimally monitor animal movements can be challenging. In this
study the receiver array was optimised through a series of incremental steps to achieve
an efficient design that allowed for the specific objectives to be addressed.
The specific objectives of this study were to i) gain an understanding of the long term
space use patterns and site fidelity of sub-adult N. acutidens within degree of use of the
St. Joseph Atoll lagoon and surrounding habitats, and ii) investigate their short term
behavioural patterns in response to natural rhythmic cycles.
The important role the atoll plays in the sub-adult stage of this species was
demonstrated by the very low numbers of detections outside the atoll compared to the
very large numbers of detections inside the atoll. Over the course of a year the tagged
sharks showed a high degree of site fidelity to the atoll, with 79 – 100% of the
individuals detected during each month and 50% being detected on a near daily basis.
This result provides testimony of the nursery role of the atoll and importance of these
habitats in the early life history for this species. Individual area use was generally found
to be restricted to the eastern part of the atoll incorporating a portion of the central deep
lagoon and a nearby adjacent area of the sand flats. The movements of sub-adult N.
acutidens on and off of the shallow flats surrounding the central lagoon (likely for
foraging) were found to be strongly influenced by the tidal height and the diel cycle.
Tagged sharks were found to utilise the flats more regularly when the tidal height was
greater than 90 cm and particularly more so during the night and early morning than
during daylight times.
The combined results of this study expose the vulnerability of this species to rapid local
depletion. Similarly, the effectiveness of spatial management measures, such as no-take
marine protected areas is highlighted as an efficient tool for the future conservation of
this species. In the St. Joseph Atoll in particular, the use of a multi-levelled protection
approach, where the eastern portion on the atoll is completely restricted while the
remaining area is utilized for non-consumptive tourism activities, could be highly
effective. Future research should investigate changes in area use throughout the
ontogeny of this species as well improve the understanding of the breeding site fidelity
and population size of reproductive females using the St. Joseph Atoll
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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