1,721,173 research outputs found
Emigrazione, Immigrazione, Convivenza interetnica
No full textWithin the context of a series of volumes devoted to the history of the Italian culture, this long essay describes the transition of Italy from a country of emigration to a country of immigration; the demographic, economic, cultural and socio-political impact of immigrants’ presence; the attitudes of Italians and of Italian government and institutions toward the migration phenomena. On the basis of a rich set of studies and empirical researches the Author develops an original analysis of these processes, demonstrating how migration functions as a “mirror” in reflecting the main characters of the Italian society and of the Italian institutional context and evidencing the most critical elements for the future of the interethnic society
Homo sapiens. La grande storia della diversità umana. (contributo paritario dei due autori)
No full textSiamo in viaggio, da due milioni di anni. Da quando i primi esemplari del genere Homo si diffusero dal continente africano e colonizzarono anche l’Eurasia. Da quando – molto, molto tempo dopo - piccoli gruppi appartenenti alla nostra specie, Homo sapiens, uscirono ancora dall’Africa e affrontarono l’esplorazione di vecchi e nuovi mondi. Oggi quell’avventura non è ancora finita e non esiste frammento delle terre emerse di questo pianeta che non abbia visto il passaggio o l’insediamento di esseri umani. Da quegli sparuti pionieri si è generata una popolazione che sfiora i sette miliardi di individui. Siamo una specie planetaria, diffusa ovunque, eppure con un’origine africana recente. Come è avvenuta la straordinaria globalizzazione di Homo sapiens? E a spese di chi
Serotonin binding proteins from human blood platelets. An experimental model system for studies on properties of synaptic vesicles
No full textSerotonin uptake, binding and release were studied in human blood platelets. The uptake showed marked individual differences while the loss of 5-HT during resuspension of the 5-HT loaded platelets was constant. The existence of 5-HT binding proteins was demonstrated by equilibrium dialysis, gel filtration on a column equilibrated with 5-HT, affinity chromatography on a 5-HT-Sepharose column and polyacryl-amide disc gel electrophoresis experiments. After incubation of the platelet extract in the presence of [14-C]5-HT, electrophoretic and autoradiographic analysis demonstrated the presence of three 5-HT binding proteins, two of which were soluble glycoproteins specific for serotonin
3D-CFD Methodologies for a Fast and Reliable Design of Ultra-Lean SI Engines
No full textThe continuous pursuit of higher combustion efficiencies, as well as the possible usage of synthetic fuels with different properties than fossil-ones, require reliable and low-cost numerical approaches to support and speed-up engines industrial design. In this context, SI engines operated with homogeneous ultra-lean mixtures both characterized by a classical ignition configuration or equipped with an active prechamber represent the most promising solutions. In this work, for the classical ignition arrangement, a 3DCFD strategy to model the impact of the ignition system type on the CCV is developed using the RANS approach for turbulence modelling. The spark-discharge is modelled through a set of Lagrangian particles, whose velocity is modified with a zero-divergence perturbation at each discharge event, then evolved according to the Simplified Langevin Model (SLM) to simulate stochastic interactions with the surrounding gas flow. For the active prechamber configuration, instead, a CFD methodology based on a 3DRANS approach is proposed to model the combustion process, in which the air-fuel mixture distribution inside the prechamber is properly considered without a 3D simulation of the main chamber intake process. This is carried out through a non-reacting simulation of the prechamber-only until IVC, then results are interpolated on a different 3D engine mesh for the further compression and combustion stages. The proposed methodologies were assessed and validated against experimental measurements at different operating conditions
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
Il viaggio dell'umanità: il punto di vista della linguistica
No full textIl volume in questione contiene testi e materiali tratti dalla grande esposizione 'Homo Sapiens. La grande storia della diversità umana', organizzata a Roma, presso il Palazzo delle Esposizioni, tra il 2011 e il 2012 e curata dagli autori del volume, Telmo Pievani e Luigi Luca Cavalli Sforza. La mostra ricostruisce, per la prima volta, le vicende di tutte le specie 'homo' che hanno accompagnato l'homo sapiens nel corso della sua storia. Solo nel quadro di una analisi globale delle specie 'homo' è possibile cogliere a fondo la straordinarietà del destino dei sapiens. Il contributo in questione fa parte di una serie di saggi introduttivi, che occupano la prima parte del volume e si propone di fornire una chiave di lettura 'linguistica' alle vicende che hanno caratterizzato la storia di homo sapiens. Aristotele definì l'uomo come "l'animale parlante": il linguaggio pare, dunque, la nostra caratteristica distintiva in natura. La storia dell'uomo, dunque, non può essere analizzata prescindendo dall'evoluzione di questa sua facoltà, che chiama in causa una rete assai complessa di fattori di ordine culturale e naturale
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