1,721,161 research outputs found
State estimation: A comparison between direct state measurement and tomography
No full textWe compare direct state measurement (DSM, or weak state tomography) to conventional state reconstruction (tomography) through accurate Monte Carlo simulations. We find that DSM is much less precise than tomography, but it is surprisingly robust to its inherent bias, which introduces an unavoidable error in the reconstruction. In addition to studying DSM and proposing a method to estimate such bias from the experimental data, we show that the number of DSM measurements can be optimized and that the dimensionality of the DSM pointer is irrelevant: Both finite- and infinite-dimensional pointers provide comparable reconstructions
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
Novel arylpyrrolylaminoquinolines as potent antimalarial agents
No full textIn order to develop new classes of antimalarial agents, we recently explored the possibility of replacing the phenolic ring of amodiaquine and tebuquine with other kinds of aromatic rings such as a pyrrole nucleus, still linked to the quinoline moiety through the usual NH. We showed that this new class of compounds is associated with a good antimalarial activity also against chloroquine-resistant (CQ-R) strains of P. falciparum.1
Starting from this evidence, a set of new 7-chloro-4-[N-[2-methyl-[5-(4-R-phenyl)pyrrol-1-yl]amino]quinoline (1a,b-4a,b) and 7-chloro-4-[N-[3-(5-(4-chlorophenyl)-2-methylpyrrol-1-yl]propyl]amino]quinoline (5a,b), bearing a diethylaminomethyl or a pyrrolidinomethyl moiety as basic head, was synthesized, in order to explore the best electronic and lipophilic requirements for the antimalarial activity of this class of compounds. In particular, the role of the substituent in the para position of the phenyl ring, as well as the role of the distance between the pyrrolic nitrogen and the 4-aminoquinoline was investigated. Moreover, the inhibition of beta-haematin formation by some representative compounds indicate that their mechanism of action is similar to CQ.
All compounds exhibited high activity against D-10 (CQ-S) strain of P. falciparum, which was comparable to that of CQ, while a clear correlation between the lipophilicity of the different molecules and their activity on W-2 (CQ-R) strain of P. falciparum has been evidenced.
The ANTIMAL –EU18834 support is acknowledged.
(1) Casagrande, M. et al. A. Bioorg. Med. Chem. 2008, 16, 6813
Analisi di sicurezza di un impianto di stoccaggio e distribuzione dell’idrogeno con intervento dell’operatore
No full text.In questo lavoro viene presentato uno studio relativo all’analisi di sicurezza di impianti di stoccaggio e distribuzione di idrogeno gassoso per autotrazione in presenza di operatori. La presenza dell’operatore, che riveste un ruolo attivo nelle procedure di messa in sicurezza dell’impianto nel caso di incidente, ha reso necessario lo studio della simulazione del comportamento umano, come causa diretta o indiretta di incidente, evidenziando i diversi fattori di incertezza introdotti in questo tipo di analisi strettamente legati alla simulazione dell’errore umano (Human Reliability Analisys). A tale scopo si è scelta una metodologia di HRA perfettamente integrabile nel contesto della “Dynamic Event Tree Analysis” per questa tipologia d’impianto , denominata CREAM (Cognitive Reliability and Error Analysis Method) [Hollnagel, 1998]. Attraverso l’analisi integrata dell’affidabilità de i componenti e dei sistemi di sicurezza e dell’affidabilità umana è stato possibile giungere a una stima della probabilità dell’incidente di riferimento, rappresentato dall’esplosione per sovra riempimento del serbatoio, per diversi scenari di gestione stimandone le relative incertezzeThis paper presents a study on the safety of storage facilities and distribution of gaseous hydrogen in the presence of operators. The presence of the operator, which plays an active role in the procedures for safety of the plant in the event of an accident, has necessitated the study of the simulation of human behavior, as a direct or indirect cause of accident, highlighting the various factors of uncertainty introduced in this type of analysis closely related to the simulation of human error (HRA - Human Reliability Analysis). For this purpose, we have chosen a CREAM (Cognitive Reliability and Error Analysis Method) method of HRA perfectly integrated in the context of the plants "Dynamic Event Tree Analysis". Through the integrated analysis of the reliability of components, safety systems and human reliability was possible to arrive at an estimate of the overall probability of the incident represented by the explosion to overfilling of the tank, for different management scenarios with the estimate of related uncertainties.
Indagini conoscitive relative alle problematiche inerenti lo smaltimento geologico dei rifiuti radioattivi ad alta attività e lunga vita
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