Andare oltre impressionabilità e ideologia: la ‘svolta narrativa’ e gli strumenti di analisi della biblioteconomia sociale

Con l’espressione narrative turn si fa riferimento al successo dell’approccio narrativo che si è manifestato nel campo delle scienze umane a partire dagli anni Novanta del secolo scorso. Il nostro settore non è estraneo a questo fenomeno, come dimostra una certa narrazione della biblioteca – diffusa negli ultimi anni e che in quest’ultimo periodo si sta consolidando – che si nutre di un patrimonio mitico fatto di messaggi altamente condivisibili, fortemente motivanti, sempre positivi, basati su valori indiscutibili. A partire da questa evidenza, l’articolo presenta una riflessione sulla svolta narrativa della biblioteconomia italiana: 1) dal punto di vista storico, a partire dal concetto di ‘library faith’, espressione utilizzata in America fin dagli anni Quaranta del Novecento per indicare l’‘ideologia’ che sostiene l’importanza della biblioteca pubblica per la società; 2) dal punto di vista metodologico, introducendo le sue due declinazioni, una che impiega lo storytelling come strumento di advocacy; l’altra che utilizza la narrazione come strumento di indagine. Nell’ultima parte dell'articolo viene introdotta l’analisi automatica dei testi (AAT) come metodo che può essere proficuamente utilizzato anche nel nostro settore al fine di incrementare la comprensione del fenomeno biblioteca e, dunque, produrre narrazioni coerenti e non slegate dai dati di realtà. Sei esperti sono stati chiamati a confrontarsi sulle specificità di questo metodo, le cui caratteristiche vengono presentate nell’ambito di una più ampia riflessione sugli strumenti interpretativi della biblioteconomia sociale.‘Narrative turn’ is the phrase used to refer to the success that narrative approach has been having in humanities since the Nineties. Our field is not foreign to this phenomenon: during these last years a narrative approach to the library is emerging, based upon myths built around shared, motivating and positive messages and undisputable values. Starting from this evidence, the article deals with the narrative turn in Italian librarianship: 1) from the historical point of view: since the Forties of the twentieth century, in the United States, the ideology supporting the public libraries’ central role of in society was studied under the name of ‘library faith’; 2) from the methodological point of view in all its different aspects: the one using storytelling as a means of advocacy; the other using stories as a knowledge production tool. The last part of the essay introduces the automatic text analysis as a method our field could use to better understand ‘library phenomenon’ and build up stories that are more coherent and tied to facts and data. Six experts have been involved in a debate about the specificity of this method, described as part of a wider discussion about social librarianship’s analytical tools

Directional pinning and anisotropy in YBa2Cu3O7-x with BaZrO3 nanorods: intrinsic and nanorods-induced anisotropy

We present a study of the anisotropic vortex parameters as obtained from measurements of the microwave complex resistivity in the vortex state with a tilted applied magnetic field in YBa2Cu3O7-x thin films with BaZrO3 nanorods. We present the angular dependence of the vortex viscosity $\eta$, the pinning constant k_p and the upper limit for the creep factor \chi_M. We show that the directional effect of the nanorods is absent in \eta, which is dictated by the mass anisotropy \gamma. By contrast, pinning-mediated properties are strongly affected by the nanorods. It is significant that the pinning and creep affected by the nanorods is detectable also at our very high operating frequency, which implies very short-range displacements of the vortices from their equilibrium position.Comment: Proceedings of VORTEX VIII Conference, to be published in Physica

Strong reduction of field-dependent microwave surface resistance in YBa2_{2}Cu3_{3}O7−δ_{7-\delta} with sub-micrometric BaZrO3_3 inclusions

We observe a strong reduction of the field induced thin film surface resistance measured at high microwave frequency ($\nu=$47.7 GHz) in YBa$_{2}$Cu$_{3}$O$_{7-\delta}$ thin films grown on SrTiO$_3$ substrates, as a consequence of the introduction of sub-micrometric BaZrO$_3$ particles. The field increase of the surface resistance is smaller by a factor of $\sim$3 in the film with BaZrO$_3$ inclusions, while the zero-field properties are not much affected. Combining surface resistance and surface reactance data we conclude (a) that BaZrO$_3$ inclusions determine very deep and steep pinning wells and (b) that the pinning changes nature with respect to the pure film.Comment: RevTeX; 4 pages, 3 figures; submitted to Applied Physics Letter

Reduction of the field-dependent microwave surface resistance in YBa_2Cu_3O_7 with sub-micrometric BaZrO_3 inclusions as a function of BaZrO_3 concentration

In order to study the vortex pinning determined by artificially introduced pinning centers in the small-vortex displacement regime, we measured the microwave surface impedance at 47.7 GHz in the mixed state of YBa$_{2}$Cu$_{3}$O$_{7-\delta}$ thin films, where sub-micrometric BaZrO$_3$ particles have been incorporated. As a function of the BaZrO$_3$ content, we observe that the absolute losses slightly decrease up to a BaZrO$_3$ content of 5%, and then increase. We found that the magnetic-field-induced losses behave differently, in that they are not monotonic with increasing BaZrO$_3$ concentration: at small concentration (2.5%) the field-induced losses increase, but large reduction of the losses themselves, by factors up to 3, is observed upon further increasing the BaZrO$_3$ concentration in the target up to 7%. Using measurements of both surface resistance and surface reactance we estimate vortex pinning-related parameters. We find that BaZrO$_3$ inclusions introduce deep and steep pinning wells. In particular, the minimum height of the energy barrier for single vortices is raised. At larger BaZrO$_3$ content (5% and 7%) the phenomenon is at its maximum, but it is unclear whether it shows a saturation or not, thus leaving room for further improvements.Comment: 7 pages, 7 figure

Anisotropy and directional pinning in YBaCuO with BaZrO3 nanorods

Measurements of anisotropic transport properties (dc and high-frequency regime) of driven vortex matter in YBa$_2$Cu$_3$O$_{7-x}$ with elongated strong-pinning sites (c-axis aligned, self-assembled BaZrO$_3$ nanorods) are used to demonstrate that the effective-mass angular scaling takes place only in intrinsic physical quantities (flux-flow resistivity), and not in pinning-related Labusch parameter and critical currents. Comparison of the dynamics at different time scales shows evidence for a transition of the vortex matter toward a Mott phase, driven by the presence of nanorods. The strong pinning in dc arises partially from a dynamic effect.Comment: 4 pages, 4 figures. Accepted for publication on Applied Physics Letters. With respect to v1: changed title, slightly shortene

Glutathione increase by the n-butanoyl glutathione derivative (GSH-C4) inhibits viral replication and induces a predominant Th1 immune profile in old mice infected with influenza virus

During aging, glutathione (GSH) content declines and the immune system undergoes a deficiency in the induction of Th1 response. Reduced secretion of Th1 cytokines, which is associated with GSH depletion, could weaken the host defenses against viral infections. We first evaluated the concentration of GSH and cysteine in organs of old mice; then, the effect of the administration of the N-butanoyl GSH derivative (GSH-C4) on the response of aged mice infected with influenza A PR8/H1N1 virus was studied through the determination of GSH concentration in organs, lung viral titer, IgA and IgG1/IgG2a production and Th1/Th2 cytokine profile. Old mice had lower GSH than young mice in organs. Also the gene expression of endoplasmic reticulum (ER) stress markers involved in GSH metabolism and folding of proteins, i.e. Nrf2 and PDI, was reduced. Following infection, GSH content remained low and neither infection nor GSH-C4 treatment affected Nrf2 expression. In contrast, PDI expression was upregulated during infection and appeared counterbalanced by GSH-C4. Moreover, the treatment with GSH-C4 increased GSH content in organs, reduced viral replication and induced a predominant Th1 response. In conclusion, GSH-C4 treatment could be used in the elderly to contrast influenza virus infection by inducing immune response, in particular the Th1 profile