1,721,238 research outputs found
3D Cell Models in Radiobiology: Improving the Predictive Value of In Vitro Research
Full text linkCancer is intrinsically complex, comprising both heterogeneous cellular composition and extracellular matrix. In vitro cancer research models have been widely used in the past to model and study cancer. Although two-dimensional (2D) cell culture models have traditionally been used for cancer research, they have many limitations, such as the disturbance of interactions between cellular and extracellular environments and changes in cell morphology, polarity, division mechanism, differentiation and cell motion. Moreover, 2D cell models are usually monotypic. This implies that 2D tumor models are ineffective at accurately recapitulating complex aspects of tumor cell growth, as well as their radiation responses. Over the past decade there has been significant uptake of three-dimensional (3D) in vitro models by cancer researchers, highlighting a complementary model for studies of radiation effects on tumors, especially in conjunction with chemotherapy. The introduction of 3D cell culture approaches aims to model in vivo tissue interactions with radiation by positioning itself halfway between 2D cell and animal models, and thus opening up new possibilities in the study of radiation response mechanisms of healthy and tumor tissues
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
Roman millstones from Orvieto (Italy): petrographic and geochemical data for a new archaeometric contribution
No full textAcqua virtuale nella dieta, nella spesa, nello spreco alimentare
No full textL’atto del cibarsi, nei paesi sviluppati, è un’azione che mediamente ognuno di noi compie almeno tre volte al giorno ed è diventato un atto talmente abituale e scontato che non gli si attribuisce più il valore e il peso che meriterebbe, sebbene sia essenziale per la nostra sopravvivenza. Nutrirsi sembra quindi un atto che per molti di noi ha perso valore, e non solo quello economico, ma anche e soprattutto quello etico, sociale, culturale, ambientale e biologico. Questo è dimostrato dal fatto che a livello europeo il 43% dello spreco alimentare ha luogo a livello domestico. Se tutti noi considerassimo il cibo un bene essenziale per la vita, sicuramente non lo sprecheremmo. Lo spreco viene perpetrato, senza la consapevolezza delle sue conseguenze, anche in termini di spreco di risorse utilizzate per la sua produzione. Forse, al fine di ridurre tale fenomeno, potrebbe essere utile quantificare le ingenti risorse che vengo impiegate.
Con questo contributo cercheremo quindi di dare una nuova chiave di lettura dei nostri modelli alimentari, ponendo in risalto che impatto idrico possono avere a seconda degli stili di consumo adottati.
Prendendo come riferimento il lavoro di Loius Malassis, che, alla fine degli anni ’80, classificò le diete in base al loro modello agronutrizionale (Man), riclassificando i diversi modelli alimentari con dati aggiornati, si cercherà di fornire una quantificazione dell’impatto idrico delle diete, avvalendoci principalmente dei risultati delle ricerche di Allan e Hoekstra in termini di consumi idrici degli alimenti.
In definitiva il contributo ha come obiettivi quello di evidenziare i consumi di acqua virtuale dei differenti modelli agronutrizionali, alla base dei differenti stili di vita e di consumo, ma anche di porre in evidenza come piccole modifiche di questi possono determinare variazioni in termini di impatto idrico e una conseguente riduzione sulla pressione delle risorse idriche mondiali
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
Provenance of Medieval pietra ollare artefacts found in archaeological sites of Central-Eastern Italy:insights into the Alpine soapstones trade.
No full textMedieval archaeological findings made of pietra ollare (basic and ultrabasic metamorphic rocks belonging to the greenschist facies) and coming from central–eastern Italy have been characterized through a petrological study (modal mineralogy, whole-rock geochemistry, XRD and SEM–EDS analyses). The pietra ollare
artefacts considered in this work consist of fine-grained, grey to pale-grey, magnesite-bearing talc-schists (i.e., soapstones). In order to determine their production centres, Alpine soapstones quarried in ancient times were selected on the basis of their mineralogical and textural compatibility with the archaeological findings.
The mineralogy and chemistry (major and trace elements) contributed to establishing the ancient quarries of the Valchiavenna (central Alps) as the probable provenance area. This archaeometric investigation proves that Alpine artefacts made of pietra ollare spread to the south of the Po Plain during the Middle Ages. It can be inferred that the Alpine soapstone trade towards the Marche and Abruzzo regions was addressed through the main waterways: Lake Como, the Adda and Po Rivers and finally the Adriatic Sea
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