406 research outputs found
Mutual information in changing environments: Nonlinear interactions, out-of-equilibrium systems, and continuously varying diffusivities
No full textBiochemistry, ecology, and neuroscience are examples of prominent fields aiming at describing interacting systems that exhibit nontrivial couplings to complex, ever-changing environments. We have recently shown that linear interactions and a switching environment are encoded separately in the mutual information of the overall system. Here we first generalize these findings to a broad class of nonlinear interacting models. We find that a new term in the mutual information appears, quantifying the interplay between nonlinear interactions and environmental changes, and leading to either constructive or destructive information interference. Furthermore, we show that a higher mutual information emerges in out-of-equilibrium environments with respect to an equilibrium scenario. Finally, we generalize our framework to the case of continuously varying environments. We find that environmental changes can be mapped exactly into an effective spatially varying diffusion coefficient, shedding light on modeling of biophysical systems in inhomogeneous media.LB
On the Cauchy–Nicoletti Type Two-Point Boundary-Value Problem for Fractional Differential Systems
No full textWe deal with a system of quasilinear fractional differential equations, subjected to the Cauchy–Nicoletti type boundary conditions. The task of explicit solution of such problems is difficult and not always solvable. Thus we suggest a suitable numerical–analytic technique that allows to construct an approximate solution of the studied fractional boundary value problem with high precision.Mathematical Physic
Information-driven transitions in projections of underdamped dynamics
No full textLow-dimensional representations of underdamped systems often provide useful insights and analytical tractability. Here, we build such representations via information projections, obtaining an optimal model that captures the most information on observed spatial trajectories. We show that, in paradigmatic systems, the minimization of the information loss drives the appearance of a discontinuous transition in the optimal model parameters. Our results raise serious warnings for general inference approaches, and they unravel fundamental properties of effective dynamical representations impacting several fields, from biophysics to dimensionality reduction
Erratum to: Effect of moderate red wine intake on cardiac prognosis after recent acute myocardial infarction of subjects with Type 2 diabetes mellitus (Diabetic Medicine, (2006), 23, 9, (974-981), 10.1111/j.1464-5491.2006.01886.x)
No full textIn an article by Marfella et al, the author name C. Saron is incorrect and should be listed as C. Sardu. Therefore the correct author list is: R. Marfella, F. Cacciapuoti, M. Siniscalchi, F. C. Sasso, F. Marchese, F. Cinone, E. Musacchio, M. A. Marfella, L. Ruggiero, G. Chiorazzo, D. Liberti, G. Chiorazzo, G. F. Nicoletti, C. Sardu, F. D'Andrea, C. Ammendola, M. Verza and L. Coppola.In an article by Marfella et al, the author name C. Saron is incorrect and should be listed as C. Sardu. Therefore the correct author list is: R. Marfella, F. Cacciapuoti, M. Siniscalchi, F. C. Sasso, F. Marchese, F. Cinone, E. Musacchio, M. A. Marfella, L. Ruggiero, G. Chiorazzo, D. Liberti, G. Chiorazzo, G. F. Nicoletti, C. Sardu, F. D'Andrea, C. Ammendola, M. Verza and L. Coppola
Excitation-Inhibition Balance Controls Information Encoding in Neural Populations
No full text: Understanding how the complex connectivity structure of the brain shapes its information-processing capabilities is a long-standing question. By focusing on a paradigmatic architecture, we study how the neural activity of excitatory and inhibitory populations encodes information on external signals. We show that at long times information is maximized at the edge of stability, where inhibition balances excitation, both in linear and nonlinear regimes. In the presence of multiple external signals, this maximum corresponds to the entropy of the input dynamics. By analyzing the case of a prolonged stimulus, we find that stronger inhibition is instead needed to maximize the instantaneous sensitivity, revealing an intrinsic tradeoff between short-time responses and long-time accuracy. In agreement with recent experimental findings, our results pave the way for a deeper information-theoretic understanding of how the balance between excitation and inhibition controls optimal information-processing in neural populations
Supplemental Material - Disadvantaged communities have lower access to urban infrastructure
No full textSupplemental Material for Disadvantaged communities has lower access to urban infrastructure by Leonardo Nicoletti, Mikhail Sirenko and Trivik Verma in Environment and Planning B: Urban Analytics and City Science</p
Correction to: Prevalence and predictors of bowel dysfunction in a large multiple sclerosis outpatient population: an Italian multicenter study (Journal of Neurology, (2022), 269, 3, (1610-1617), 10.1007/s00415-021-10737-w)
No full textThe original version of this article unfortunately contained a mistake. The given and family names of authors were Interchanged except the following author Maria Chiara Buscarinu, Carolina Gabri Nicoletti, Alessandra Girolama Marfia and Antonio Gallo
Supplemental material for Polyurethane tissue adhesives for annulus fibrosus repair: Mechanical restoration and cytotoxicity
No full textSupplemental Material for Polyurethane tissue adhesives for annulus fibrosus repair: Mechanical restoration and cytotoxicity by Lucas Dall Agnol, Fernanda Trindade Gonzalez Dias, Natália Fontana Nicoletti, Daniel Marinowic, Sidnei Moura e Silva, Angel Marcos-Fernandez, Asdrubal Falavigna and Otávio Bianchi in Journal of Biomaterials Applications</p
Mutual Information Disentangles Interactions from Changing Environments
No full textReal-world systems are characterized by complex interactions of their internal degrees of freedom, while living in ever-changing environments whose net effect is to act as additional couplings. Here, we introduce a paradigmatic interacting model in a switching, but unobserved, environment. We show that the limiting properties of the mutual information of the system allow for a disentangling of these two sources of couplings. Further, our approach might stand as a general method to discriminate complex internal interactions from equally complex changing environments.LB
Enrico Cattaneo : Fotografare un'idea
No full textOltre ad aver raccontato l’arte e gli artisti del secondo Novecento attraverso la documentazione di cinquant’anni di mostre, studi e grandi manifestazioni pubbliche in Italia, Enrico Cattaneo (Milano, 1933-2019) ha sviluppato una personalissima ricerca visuale sui modi, i soggetti e i materiali della fotografia.
Questi due aspetti della sua attività, inseparabili fra loro come le due facce di una medaglia, si ricompongono nella fisionomia unitaria di un autore capace di mettere in questione i presupposti tecnici e concettuali del linguaggio fotografico.
Come lui stesso ha scritto: “L’opera d’arte contemporanea è spesso una cosa più un’idea... Difficile fotografare un’idea”.In addition to having chronicled art and artists of the second half of the 20th century by documenting fifty years of exhibitions, art research, and major public events in Italy, Enrico Cattaneo (Milan, 1933–2019) developed a highly personal visual investigation on the modes, languages, and materials of photography.
These two facets of his activity, indissolubly linked like the two sides of a coin, are recomposed in the overall profile of an author capable of questioning the technical and conceptual foundations of photography.
As he himself has written: ‘The contemporary work of art is often made up of a tangible thing and an idea ... It is difficult to capture an idea on film.
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