1,721,071 research outputs found
Impact of inhomogeneities on slowly rolling quintessence: Implications for the local variations of the fine-structure constant
No full textWe study how the evolution of a dark energy quintessence fluid is modified by the presence of a matter inhomogeneity. To do so, we study linear perturbations of a flat FLRW background containing dust and a slowly rolling scalar field. Under the assumptions of spherical symmetry and a static density contrast, i.e. δ = 0, we obtain simple analytical solutions for perturbations in the matter and dark energy-dominated epochs. As a consequence, we show that perturbations of the scalar field, if a coupling a la Bekenstein is assumed, trigger a spatial dependence of the fine-structure 'constant' which then varies as Δα ⋊ 1/r. We finally highlight that such variations can be constrained with spectroscopic observations of stars from within our galaxy, therefore offering a new probe of the nature of dark renergy
Stress antropico e condizioni ecologiche delle praterie diPosidonia oceanica(L.) Delile nel Parco Nazionale di La Maddalena (NE Sardegna) = Stress of anthropic effects and ecological conditions of thePosidonia oceanicafields in the Maddalena National Park (NE Sardinia)
Full text linkThree years of summer sampling, from 1999 to 2001, have permitted the verification of a close relationship between the depletion ofPosidonia oceanicabed in Maddalena National Park (NE Sardinia) and several factors of anthropogenic origin. Among them, the increase in water turbidity and the effects of boats anchoring on the sea floor are the principal causes for the reduction ofthe density, leaf length and coverage of the phanerogam. 78 circular areas 40 meters in diameter has been monitored by SCUBA diving, glass floored inflatable dinghy and a high definition (600 kHz) side scan sonar with a coverage of approximately 300 hectares, allowing the identification of the most affected areas and the quantification of the effects. The consequences of these effects onP. oceanicabeds are evident by comparison with the values measured in non affected areas
Autonomia lavorativa e benessere nella professione infermieristica: l’influenza del contesto di lavoro e del percorso formativo
No full textLa mancanza di autonomia è un fattore di rischio particolarmente rilevante per il benessere lavorativo degli infermieri, soprattutto a seguito della riforma che a partire da metà degli anni ’90 ha modificato profondamente il loro profilo professionale.
L’obiettivo della ricerca è quello di studiare la relazione tra autonomia e benessere degli infermieri, considerandoli come categoria eterogenea e differenziandoli in base al contesto di svolgimento del lavoro (area dipartimentale) e al tipo di formazione ricevuta (percorso formativo).
I dati raccolti attraverso un questionario somministrato a 69 infermieri confermano l’effetto di moderazione di entrambe le variabili. L’autonomia predice il benessere solo nell’area dipartimentale geriatrico-riabilitativa e, in questa, in misura maggiore per gli infermieri con una formazione di tipo professionale.
I risultati, che confermano la necessità di considerare gli infermieri come categoria eterogenea, vengono discussi in relazione al diverso significato che l’autonomia può assumere in contesti
sanitari diversi e al diverso valore che infermieri con particolari caratteristiche personali le possono dare. Tali differenze sono critiche per pianificare interventi mirati per la riduzione del rischio stress lavoro-correlato
Stress antropico e condizioni ecologiche delle praterie di Posidonia oceanica (l.) Delile nel parco nazionale di La Maddalena (NE Sardegna)
No full textItinerari interrotti: il pensiero di Franco Ledda ed Antonio Romano Tassone per una ricostruzione del diritto amministrativo
No full textI diritti fondamentali degli immigrati tra emergenza rifugiati e crisi economico/finanziaria: quale ruolo per le amministrazioni?
No full textIl lavoro affronta il delicato tema dei diritti fondamentali degli immigrati, in particolare del diritto alla salute in un momento, come quello attuale, in cui il Paese è attanagliato da una grave crisi economica. Il tema viene studiato nel contesto della legislazione vigente, del quadro europeo, nonché alla luce della giurisprudenza costituzionale, che ha individuato un “nucleo forte” nel diritto alla salute che non può essere intaccato da problemi di natura finanziaria. Ma accanto al diritto alla salute si pone il problema di garantire anche i diritti sociali degli immigrati (alla casa, all’istruzione, ecc.), diritti la cui tutela ed effettività spetta all’amministrazione
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
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