1,720,969 research outputs found
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
Components of standard metabolic rate variability in three species of gammarids
Get PDFStandard metabolic rate is
a major functional trait with large inter-individual variability in many
groups of aquatic species. Here we present results of an experimental study
to address variation in standard metabolic rates, over different scales of
organisation and environments, within a specific group of aquatic
macro-invertebrates (i.e. gammarid amphipods) that represent the primary
consumers in detritus food webs. The study was carried out using flow-through
microrespirometric techniques on male specimens of three gammarid species
from freshwater, transitional water and marine ecosystems. We examined
individual metabolic rate variations at three scales: (1) at the individual
level, during an 8 h period of daylight; (2) at the within-population level,
along body-size and body-condition gradients; (3) at the interspecific level,
across species occurring in the field in the three different categories of
aquatic ecosystems, from freshwater to marine.
We show that standard metabolic rates vary significantly at all three scales
examined, with the highest variation observed at the within-population level.
Variation in individual standard metabolic rates during the daylight hours
was generally low (coefficient of variation, CV<10 %) and
unrelated to time. The average within-population CV ranged between 30.0 %
and 35.0 %, with body size representing a significant source of overall
inter-individual variation in the three species and individual body condition
exerting only a marginal influence. In all species, the allometric equations
were not as steep as would be expected from the 3∕4 power law, with
significant variation in mass-specific metabolic rates among populations. The
population from the transitional water ecosystem had the highest
mass-specific metabolic rates and the lowest within-population variation.
In the gammarid species studied here, body-size-independent variations in
standard individual metabolic rates were higher than those explained by
allometric body size scaling, and the costs of adaptation to short-term
periodic variations in water salinity in the studied ecosystems also seemed
to represent a major source of variation.</p
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
MSCT study of ancient bone remains: investigative protocols
No full textObiettivo: Il nostro studio si è occupato di valutare l'ottimizzazione dell'immagine in MSCT per lo studio dei resti ossei antichi. Nonostante l'esperienza di numerosi anni per lo studio di immagini anatomiche di piccole dimensioni come ad esempio la catena ossiculare dell'orecchio medio in bambini. L'ostacolo maggiore per i reperti antichi è stato che tutti i protocolli non tenevano conto dell’assenza dei tessuti molli.
Materiali e metodo: Abbiamo utilizzato per il nostro studio due reperti archeologici messi a disposizione dalla Soprintendenza Speciale per il Colosseo e l’Area Archeologica Centrale di Roma (Castel Malnome ) che sono stati sottoposti a varie esposizioni con apparecchiatura TC Toshiba Aquilion 16 strati. Si è proceduto a 5 tipologie di esposizione al fine di identificare i protocolli con variazione dei parametri di acquisizione iniziando da un corretto centraggio del reperto, del FOV, dei kV e dei mA, tempo di esposizione, pitch e la selezione del filtro più idoneo.
Risultati: La tabella di riferimento dei risultati piuttosto articolata ha evidenziato che pur avendo dei limiti tecnici dovuti alla macchina si possono eseguire esami a bassa dose di alta qualità per tutte le attrezzature MSCT
Cone beam computed tomography after round window vibroplasty. do the radiological findings match the auditory outcome?
Get PDFConclusion: The CBCT imaging technique has proved to be reliable for assessing the appropriate positioning of the FMT in the round window niche. However, when considering specific imaging parameters, such as lack of bony contacts and appropriate inferior support, they would not seem essential for achieving a satisfactory functional outcome.
Objectives: To evaluate the value of some imaging parameters derived from a Cone Beam Computed Tomography of the temporal bone for predicting a good functional outcome after Round Window Vibroplasty (RW-VP).
Method: A CBCT imaging has been carried out at certain time after RW-VP surgery in a homogenous group of patients who presented with a mixed-type hearing loss after open tympanoplasty for a cholesteatoma. Three arbitrary radiological parameters have been considered for the purpose: the FMT/RW membrane contact; eventual FMT bony contacts; appropriatmess of inferior FMT support. The audiological assessment has taken into consideration the PTA4 (500-4000 Hertz), the PTA2 (125.250 Hertz), the WRS in quiet and in noise (SNR=+10). A comparison between the unaided and the RW-VP aided condition has been performed
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
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