1,721,163 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
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
Tracking behavioral persistence and innovations during the Middle Pleistocene in Western Europe. Shift in occupations between 700 and 450 ka at la Noira site (Centre, France)
No full textSome areas in Western Europe indicate hiatuses in human occupations, which cannot be systematically attributed to taphonomic factors and poor site preservation. The site of la Noira in the center of France records two occupation phases with a significant time gap. The older one is dated to around 700 ka (stratum a) with an Acheulean assemblage, among the earliest in Western Europe, and the upper phase of the sequence (stratum c) is dated to ca. 450 ka. Humans left the area at around 670 ka, at the beginning of the marine isotope stage (MIS) 16 glacial stage, when cold conditions became too severe. No sites between 650 and 450 ka have yet been discovered in the center region despite systematic surveys over the past three decades. The archaeological evidence indicates that populations returned to the area, at the end of MIS 12 or the beginning of the long interglacial MIS 11. Here, we use technological behaviors common to the two levels of la Noira—strata a and c to evaluate their differences. Compared to other key European sequences, this site can be used to address the evolution of the behavioral strategies in Europe between MIS 17 and 11. We formulate two hypotheses concerning the human settlement of this area: (1) local behavioral evolution over time of populations occasionally occupying the region when the climate was favorable or (2) dispersal and arrival of new populations from other areas. The results focus on (1) changes in land-use patterns with the extension of the territory used by hominins in the upper level, (2) the introduction of new core technologies, including some evidence of early Levallois debitage, and (3) more intensive shaping of bifaces and bifacial tools. Results attest that the la Noira archaeological assemblages record similar regional behavioral evolution as observed at a larger scale in Europe
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
Datazione tramite i metodi Uranio -Torio (U/Th) e Electron Spin Resonance (ESR) dei livelli musteriani della Grotta Maggiore di San Bernardino
No full textLe grotte di San Bernardino si trovano sul versante orientale dei Colli Berici, a 135 m d’altezza (s.l.m.). Nella Grotta Maggiore, la sequenza stratigrafica non si è conservata interamente a causa dei numerosi riutilizzi durante il Medioevo e nel diciannovesimo secolo. La serie interna, ha restituito un’industria litica attribuita al Paleolitico superiore; la serie esterna, collocata oltre il muro medievale che chiude l’entrata della cavità, è caratterizzata da un’industria musteriana che si differenzia, per le sue caratteristiche, dagli altri complessi litici della regione.
In complesso il deposito ha uno spessore di 4,5 metri ed è costituito da otto unità stratigrafiche con disposizione sub-orizzontale. Nella stratigrafia s’incontrano unità scarsamente antropizzate, costituite principalmente da pietrisco proveniente dalla volta della grotta e dalle pareti per effetto del gelo-disgelo misto a loess (unità I,V,VII), da loess bruno-chiaro senza pietre (unità IV) e ciottoli calcarei arrotondati per stillicidio (unità III). Le unità più ricche di resti animali, manufatti e tracce di focolari sono le unità II, VI e VIII, costituite prevalentemente da pietrisco e da un terreno ricco di sostanza organica.
La datazione del giacimento è stata effettuata, tramite i metodi U-Th e ESR, in un primo momento su frammenti di ossa e solo recentemente su denti di grandi mammiferi, due provenienti dalla base del giacimento (strati 26-unità VIII e 24-unità VI) e uno dalla sommità della sequenza stratigrafica (strato 4- unità II).
Il metodoUranio-Torio si basa sullo studio del disequilibrio delle famiglie dell’uranio. L’età si ricava misurando il rapporto 230Th/ 234U, elementi radioattivi di questa serie. I due elementi presentano caratteristiche chimiche diverse: al contrario del torio (230Th), l’uranio (234U) solubile nell’acqua e trasportato da essa, si accumula nei campioni o durante la loro formazione (banchi stalamigtici, stalagmiti, coralli, ecc..) o durante il loro infossamento come nel caso di ossa e denti. Il torio (230Th), insolubile all’acqua, si manifesta nel campione grazie al decadimento radioattivo dell’uranio (234U). Il range di tempo coperta da questo metodo è compresa tra 10000 e 350000 anni, ma utilizzando uno spettrometro di massa a termo-ionizzazione (TIMS), è possibile risalire a 500.000 anni.
L’Electron Spin Resonance permette di datare avvenimenti archeologici e geologici di tutto il Quaternario e presenta inoltre l’enorme vantaggio d’essere applicabile a numerosi materiali quali i carbonati (continentali e marini), le idrossidapatiti (denti e ossa) e il quarzo “sbiancato” termicamente, come nel caso delle selci bruciate, delle ceramiche, delle rocce vulcaniche, o otticamente, come ad esempio i sedimenti (lœss, sedimenti fluviali, ecc...). L’età di un campione si basa sulla determinazione di due grandezze fisiche: la Paleodose, cioè la dose totale d’irradiazione naturale ricevuta dal campione nel corso della sua storia (ad esempio dal suo infossamento al momento in cui viene ritrovato, nel caso di ossa e denti) e la dose annuale, ossia la dose naturale assorbita dal campione in un anno. Quest’ultima può essere espressa come la somma delle dosi dei diversi raggi ionizzanti (α, β, γ, e raggi cosmici) che investono il campione durante un anno di esposizione, la cui origine è sia interna, cioè prodotta dagli elementi radioattivi presunti nel campione stesso, sia esterna, prodotta dall’ambiente circostante. La dose esterna può essere valutata sia sui sedimenti che inglobavano il campione sia, tramite l'utilizzo di dosimetri teroluminescenti (TL).
I risultati ottenuti sui denti permettono di datare l'occupazione della grotta di San Bernardino tra lo stadio isotopico 7 (unità VIII) e lo stadio isotopico 3 (unità II), confermando le età ottenute sui reperti ossei. Questi risultati, ottenuti misurando la dose gamma esterna su sedimenti prelevati nell'intorno del campione, saranno rielaborati tenendo conto delle dosi esterne, che verranno misurate tramite dosimetri termoluminescenti posti in numerosi livelli della sequenza stratigrafica
Dating the Middle Palaeolithic of Fumane Cave by the combined ESR/U‐series method
No full textFumane Cave, located in Northern Italy, is a major prehistoric site for understanding late Neandertal and early modern human behaviours. The cave contains a 12‐m‐thick stratigraphic sequence of Middle and Upper Palaeolithic layers, which have yielded a number of flint artefacts and faunal remains. The upper part of the stratigraphic sequence is well‐dated using radiocarbon analysis, placing the last Middle Palaeolithic occupations at
ca. 44–45 ka cal BP and the first Upper Palaeolithic occupations (Uluzzian and Aurignacian) after around 43 ka cal BP. However, the lower part of the stratigraphic sequence remains less well‐documented chronologically. Previous thermoluminescence (TL) dating placed the entire sequence within the last climatic cycle, following the last Interglacial stage (MIS 5e). In this study, we present a revised chronology for the Middle Palaeolithic levels at Fumane
Cave, based on combined Electronic Spin Resonance/Uranium (ESR/U)‐series dating of herbivorous teeth spanning much of the sequence. Our results diverge from earlier TL data, indicating that the oldest layers date to MIS 7–6 (units S9–S3) and MIS 6–5 (units BR12–BR9). For the late Mousterian (units A11–A4) and the Upper Palaeolithic (unit A2),
recalculated ages using new in situ gamma measurements align with existing radiocarbon and TL dates. However, our findings highlight the methodological challenges of applying ESR/U‐series dating to samples younger than 50 ka, particularly in heterogeneous layers. These new results suggest that Middle Palaeolithic occupations at Fumane Cave
spanned over 200 ka, covering the two most recent climatic cycles. This extended temporal framework parallels that of San Bernardino cave, another key site in Northern Italy, and underscores the prolonged presence of Levallois technology in the region
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
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