1,721,044 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
Lo scavo del Riparo del Biserno (San Vincenzo, Livorno).
No full textNell'ottobre 1988 è stato effelluato uno scavo di emergenza nel deposito archeologico del Riparo Bisemo, ubicato in località San Carlo, frazione del Comune di San Vincenzo (LI); il
modesto riparo stava infatti per essere distrutto dall'attività estrattiva di una cava di calcare. La cavità, la cui stratigrafia risultava sconvolta, era stata adibita ad usifunerari in due distinti
periodi: probabilmente nell'Eneolitico e, sicuramente, nell'età del Ferro. Sarebbero riferibili alle deposizioni più antiche alcuni resti umani fossilizzati e scarsi resti ossei di UI1 individuo eremato,
oltread una lametta di ossidiana e, presumibilmente, a due vaghi ricavati dalla conchiglia di un mollusco. Risalgono invece ad epoca più recente i resti di almeno quattro inumati, uno dei quali di sesso femminile; gli scarsi elementi di corredo recuperati comprendono infarti, fra l'altro, un ago per cucire, frammenti di una spiralina [ermatrecce ed una fibula ad arco lievemente ingrossato nella parte mediana. Tali reperti sono databili fra la fine del IX secolo a.c.
e gli inizi dell'VIII.
L'inumazione di salme in anfratti naturali è una pratica funeraria assai rara in epoca villanoviana. L'unico confronto istituibile con il ritrovamento delRiparo Biserno è costituito infatti dalla scoperta di un gruppo di inumati all'interno di una grotta del Monte Calamita (isola d'Elba). È particolarmente interessante sottolineare la circostanza che entrambi i rinvenimenti sono stati effettuati nell'ambito di due importanti distretti minerari limitrofi, quali le colline del Campigliese edi giacimenti elbani; l'esame del materiale archeologico associato alle deposizioni fa inoltrepropendere per una sostanziale contemporaneità nell'adozione di tale rito, sia nel Riparo
Bisemo che sul Monte Calamita
Effect of chemical structure and hydrophobicity on the pharmacokinetic properties of porphycenes in tumour-bearing mice
No full textThe efficiency and selectivity of tumour targeting by several tetra-n-propylporphycene (TPPn) and tetrakis(methoxyethyl)porphycene (TMPn) derivatives have been studied by administering 3.76 micromol/kg of aqueous or liposomal porphycene formulations to BALB/c mice bearing an i.m. implanted MS-2 fibrosarcoma. These 2 parameters have been studied as a function of the type of substituents linked to the 9-position of the macrocycle by amide, ester or ether functional groups. The pharmacokinetic properties appear to be controlled mainly by the degree of porphycene hydrophobicity, as evaluated by measuring their retention times in a C 18 column for HPLC. Thus, the post-injection time (T50) at which the porphycene concentration in the plasma decreases to 50% of the initial value ranged from a few minutes for the less hydrophobic to several hours for the more hydrophobic porphycenes. An increase in hydrophobicity also was accompanied by an enhanced efficiency and selectivity of tumour targeting. The less hydrophobic porphycenes showed a maximum tumour uptake of 0.5-2 nmol/g of tissue at 10-20 min after administration with a tumour/peri-tumoural concentration ratio around 2-3, while those with higher hydrophobicity reached tumour concentrations of 7-8 nmol/g at 24-48 hr after administration with concentration ratios higher than 20
Nailfold capillaroscopy in the screening and diagnosis of Raynaud's phenomenon.
No full textRaynaud's phenomenon is in most cases idiopathic, but it may appear as secondary to other diseases. Since clinical evaluation is often inadequate to distinguish between these two forms, simple noninvasive methods are needed for an early diagnosis of the secondary form. The authors used nailfold capillaroscopy to study 58 patients with Raynaud's phenomenon--44 apparently idiopathic and 14 secondary to connective tissue diseases. In all patients affected by secondary Raynaud's phenomenon nailfold capillaroscopy confirmed the presence of an abnormal pattern with typical systemic sclerosis alterations in 5 cases. Twenty-one (48%) of the other 44 patients presented a normal capillaroscopic pattern, 15 (34%) had alterations compatible with long-term idiopathic Raynaud's phenomenon, and 8 (18%) showed abnormal capillaroscopic patterns, 2 of which were identified as the sclerodermic pattern. Nailfold capillaroscopy distinguishes between primary and secondary Raynaud's phenomenon and may be used to identify patients presenting no evidence of underlying disease who could be at risk of developing connective tissue disease
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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