1,721,272 research outputs found
The Hawking-Unruh phenomenon on graphene
No full textWe find that, for a very specific shape of a monolayer graphene sample, a general relativistic-like
description of a back-ground spacetime for graphene’s conductivity electrons is very natural. The
corresponding electronic local density of states is of finite temperature. This is a Hawking–Unruh effect
that we propose to detect through an experiment with a Scanning Tunneling Microscop
Clinical trials and haemophilia : does the Bayesian approach make the ideal and desirable good friends?
No full textWhen the disease is rare and/or the outcome is uncommon the trial design does not warrant precise and unbiased estimates due to a lack of power or the expected length of recruitment and observation periods. Is there any reliable method to control for bias and consequently achieve an advantage from estimates generated by different study designs? An interesting statistical approach suitable to solve this problem has been theorized by Thomas Bayes. A Bayesian analysis is aimed at answering the question 'How this trial will modify our belief about that treatment effect?' In summary, the Bayesian approach can be defined as the explicit and quantitative use of any kind of external evidence in the design, analysis, and interpretation of an experimental trial. The results of a Bayesian analysis is the 95% credible interval in which we believe the estimate to lie with a probability of 95%, or the estimate of the probability that the quantity of interest is less than a specific value. The principal advantages of the Bayesian approach are that it allows to directly make probability statements about quantities of interest; it allows to easily make predictive statements, conditional on the current state of knowledge; it enables evidence from a variety of sources to be taken into account within a coherent modelling framework; it requires the investigator to explicit prior beliefs and demands. Exemplifications of the advantages of the Bayesian approach will be given discussing some papers published in Haemophilia
Prospettive di utilizzo della Valutazione Economica e della Budget Impact Analysis nelle politiche del farmaco in Italia: i risultati di uno studio Delphi
No full textIn Italy decisions concerning drug reimbursement and prices seem that are not based on cost-effectiveness analysis (CEA) results or on the expected impact on health care budget i.e., budget impact analysis (BIA). This study aimed at scrutinizing the reasons of this attitude, anticipating possible future changes, by using a Delphi panel with thirteen experts in economic evaluation and pharmaceutical policy. Politicians’ distaste for explicit rationing, short-term cost-containment pressure and silos budgeting have been identified as the main obstacles to a systematic use of CEA and BIA. Although these obstacles are likely to persist in the future, consensus was reached among the experts for a broader use of CEA results at the national level, should a new drug provide considerable benefits versus a very high price, and of BIA at the regional level to support local sustainability. It is also imperative that both central and regional governments invest in post-marketing studies to evaluate whether the initial decision made when the new product was launched are consistent with a rational use of the scarce resources. Experts also advocated for (i) stronger interactions between the industry and third party payers, both at national and regional levels, especially at the drug market launch, when the industry is required to provide economic evidence and third party payers to assess this evidence, and (ii) an accredited network of research centers and professionals, supporting third party payers in this type of assessment, provided that the conflict of interest is rigorously verified
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
I confini come patrimonio : Memorie e identità europee
No full textIntroduzione ad una serie di testi che propongono di ragionare sul tema dei confini europei, passati o vigenti, attraverso l’esposizione di esperienze (progetti, piani, ricerche) in cui la lettura o il recupero di tracce e memorie siano parte fondamentale nella trasformazione del paesaggio
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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