Coherent regimes of globally coupled dynamical systems

The paper presents a method by which the mean field dynamics of a population of dynamical systems with parameter diversity and global coupling can be described in terms of a few macroscopic degrees of freedom. The method applies to populations of any size and functional form in the region of coherence. It requires linear variation or a narrow distribution for the dispersed parameter. Although being an approximation, the method allows us to quantitatively study the collective regimes that arise as a result of diversity and coupling and to interpret the transitions among these regimes as bifurcations of the effective macroscopic degrees of freedom. To illustrate, the phenomenon of oscillator death and the route to full locking are examined for chaotic oscillators with time scale mismatch.Comment: 5 pages, 3 figure

La chiesa e il convento di Santa Chiara. Committenza artistica, vita religiosa, progettualità politica nella Napoli di Roberto d’Angiò e Sancia di Maiorca

Frutto del profondo legame che unì la coppia regale Roberto d’Angiò e Sancia di Maiorca all’Ordine francescano, il complesso di Santa Chiara fu avviato nel 1310. Impiantato a ridosso delle mura della città, Santa Chiara rappresenta non solo il maggiore complesso conventuale del Regno, ma anche un luogo dove, in alcuni frangenti, politica, religione, arte risultano così intimamente convergenti nelle loro finalità da aver alimentato la convinzione di una precisa volontà di pianificare i suoi spazi e la connessa decorazione in collegamento con tendenze millenaristiche attribuite ai frati e ai loro regali patroni. Sede di sepoltura di re Roberto e dei suoi diretti discendenti, ma anche polo ideale di riferimento dell’aristocrazia di corte, nel corso del Trecento la chiesa è stata teatro dell’attività di alcuni dei più grandi artisti italiani, quali Giotto e Tino di Camaino. Gli studi di storia dell’arte sull’edificio, incrementatisi in maniera significativa dopo la Seconda Guerra Mondiale, hanno finora privilegiato in un’ottica specialistica l’esame del contenitore architettonico e dei manufatti monumentali. È mancata finora una trattazione d’insieme che affrontasse in un’ottica moderna, da un lato, il rapporto del convento con la città, dall’altro, le intime relazioni tra istanze religiose, aspettative politiche, esigenze liturgiche, uso dello spazio sacro, che hanno determinato la forma della chiesa, l’allestimento degli arredi, la caratterizzazione iconografica dei programmi figurativi. Ad alcuni di questi problemi intende dare risposta questo volume, che mette insieme affermati studiosi italiani e stranieri, particolarmente sensibili a questa impostazione di ricerca, e giovani studiosi che hanno già dato prova delle loro competenze su tali complesse tematiche

L'avversione di Ruggiero Bonghi alla Triplice Alleanza

Discorso tenuto a Campobasso il 28 giugno 191

Drifted Brownian motions governed by fractional tempered derivatives

Fractional equations governing the distribution of reflecting drifted Brownian motions are presented. The equations are expressed in terms of tempered Riemann--Liouville type derivatives. For these operators a Marchaud-type form is obtained and a Riesz tempered fractional derivative is examined, together with its Fourier transform.Comment: Published at https://doi.org/10.15559/18-VMSTA114 in the Modern Stochastics: Theory and Applications (https://vmsta.org/) by VTeX (http://www.vtex.lt/

VALUTARE LA VALUTAZIONE QUALITÀ DELLA RICERCA SCIENTIFICA E «SCIENTOMETRIA».

L’articolo analizza le premesse concettuali dell’uso della bibliometria per la valutazione della produzione scientifica con particolare riferimento agli studi umanistici e sociali, analizzando le distorsioni di un processo di valutazione che intende trasformarsi tout court in scientometria.The Authors analyse the conceptual premises of the use of “bibliometrics” for the evaluation of scientific publications, both in general, for any scientific field, and, more particularly, for social studies and humanities. The Authors do not disagree that it would be desirable, in an ideal world, to “measure” objectively and mathematically the quality of scientific (and particularly historical) research, but they contend that there exists no such method to attain this result. Bibliometrics have been introduced to “measure” with numerical and mathematical methods the “dissemination” of scientific literature, not to evaluate the quality of such literature. The principle underlying the use of bibliometric methods, such as “impact factor” or similar methods, for the evaluation of researchers is both conceptually wrong and misleading and causes distortion in the development of scientific research and publications

Comparison between Eulerian diagnostics and finite-size Lyapunov exponents computed from altimetry in the Algerian basin

Transport and mixing properties of surface currents can be detected from altimetric data by both Eulerian and Lagrangian diagnostics. In contrast with Eulerian diagnostics, Lagrangian tools like the local Lyapunov exponents have the advantage of exploiting both spatial and temporal variability of the velocity field and are in principle able to unveil subgrid filaments generated by chaotic stirring. However, one may wonder whether this theoretical advantage is of practical interest in real-data, mesoscale and submesoscale analysis, because of the uncertainties and resolution of altimetric products, and the non-passive nature of biogeochemical tracers. Here we compare the ability of standard Eulerian diagnostics and the finite-size Lyapunov exponent in detecting instantaneaous and climatological transport and mixing properties. By comparing with sea-surface temperature patterns, we find that the two diagnostics provide similar results for slowly evolving eddies like the first Alboran gyre. However, the Lyapunov exponent is also able to predict the (sub-)mesoscale filamentary process occuring along the Algerian current and above the Balearic Abyssal Plain. Such filaments are also observed, with some mismatch, in sea-surface temperature patterns. Climatologies of Lyapunov exponents do not show any compact relation with other Eulerian diagnostics, unveiling a different structure even at the basin scale. We conclude that filamentation dynamics can be detected by reprocessing available altimetric data with Lagrangian tools, giving insight into (sub-)mesoscale stirring processes relevant to tracer observations and complementing traditional Eulerian diagnostics

Chapter Post-stratification as a tool for enhancing the predictive power of classification methods

It is well known that, in classification problems, the predictive capacity of any decision-making model decreases rapidly with increasing asymmetry of the target variable (Sonquist et al., 1973; Fielding 1977). In particular, in segmentation analysis with a categorical target variable, very poor improvements of purity are obtained when the least represented modality counts less than 1/4 of the cases of the most represented modality. The same problem arises with other (theoretically more exhaustive) techniques such as Artificial Neural Networks. Actually, the optimal situation for classification analyses is the maximum uncertainty, that is, equidistribution of the target variable. Some classification techniques are more robust, by using, for example, the less sensitive logit transformation of the target variable (Fabbris & Martini 2002); however, also the logit transformation is strongly affected by the distributive asymmetry of the target variable. In this paper, starting from the results of a direct survey in which the target (binary) variable was extremely asymmetrical (10% vs. 90%, or greater asymmetry), we noted that also the logit model with the most significant parameters had very reduced fitting measures and almost zero predictive power. To solve this predictive issue, we tested post-stratification techniques, artificially symmetrizing a training sample. In this way, a substantially increase of fitting and predictive capacity was achieved, both in the symmetrized sample and, above all, in the original sample. In conclusion of the paper, an application of the same technique to a dataset of very different nature and size is described, demonstrating that the method is stable even in the case of analysis executed with all data of a population

The expression of a bean PGIP in transgenic wheat confers increased resistance to the fungal pathogen Bipolaris sorokiniana

In several plant-pathogen interactions to overcome the barrier represented by cell wall most fungal pathogens produce a variety of hydrolytic enzymes and between them PGs are one of the first to be secreted. We demonstrate that transgenic wheat plants expressing PvPGIP2 showed a significant reduction of symptoms following the infection of Bipolaris sorokiniana suggesting that pectin hydrolysis is an important step for fungal penetration of wheat plants.In molti sistemi pianta patogeno i patogeni al fine di superare l’ostacolo rappresentato dalla parete cellulare producono degli enzimi idrolitici tra cui le Poligalatturonasi ( PG) sono tra i primi ad essere secreti. In questo lavoro dimostriamo che piante transgeniche di frumento sovraesprimenti la PvPGIP2 mostrano una significativa riduzione nella sintomatologia riscontrata in seguito ad infezione con Bipolaris sorokiniana suggerendo che l’idrolisi della pectina rappresenta uno step importante per la penetrazione e la colonizzazione dei tessuti di frumento.L'articolo é disponibile sul sito dell'editore: http://www.apsjournals.apsnet.or

Production and characterization of wheat lines silenced in alpha amylase/trypsin inhibitor genes involved in adverse reactions to wheat

Although wheat is the most consumed crop worldwide, it is also the main factor triggering different adverse reactions, among which celiac disease, true allergies and Non Celiac Wheat Sensitivity (NCWS). Among allergies, the so called \u201cbaker\u2019s asthma\u201d, is the most common professional asthma in Europe and is caused mainly by proteins present in the soluble fraction, especially alpha-amylase/trypsin inhibitors (ATI). Recent findings indicate in this class of proteins also the main factor triggering NCWS, that at present affects people with a frequency around 1:80, higher than celiac disease (1:100), but this is still a matter of debate. On this basis, we have produced RNAi wheat plants (both durum and bread wheat) in which different ATI genes have been silenced, to be used as a proof of concept, in order to test if they have a minor impact on adverse reactions, by using in vitro tests. We have silenced CM3, CM16 and 0.28 genes and have now available several lines in T4 generation. ELISA tests and immunoblotting analysis, by using a monoclonal antibody against ATI proteins, have shown that RNAi silenced wheat kernels present a lower amount of ATI proteins. Moreover, we are characterizing these lines in relation to respiratory allergies. Protein extracts from silenced plants are being tested by using human sera of allergic patients in order to verify if a lower amount of immunogenic polypeptides is recognized in comparison to wild type untransformed plants. If this is the case, the realization of new wheat genotypes expressing a lower amount of ATI proteins can be a realistic target to be reached by classical breeding procedures