Experimental characterization of the transition to coherence collapse in a semiconductor laser with optical feedback

Semiconductor lasers with time-delayed optical feedback display a wide range of dynamical regimes, which have found various practical applications. They also provide excellent testbeds for data analysis tools for characterizing complex signals. Recently, several of us have analyzed experimental intensity time-traces and quantitatively identified the onset of different dynamical regimes, as the laser current increases. Specifically, we identified the onset of low-frequency fluctuations (LFFs), where the laser intensity displays abrupt dropouts, and the onset of coherence collapse (CC), where the intensity fluctuations are highly irregular. Here we map these regimes when both, the laser current and the feedback strength vary. We show that the shape of the distribution of intensity fluctuations (characterized by the standard deviation, the skewness, and the kurtosis) allows to distinguish among noise, LFFs and CC, and to quantitatively determine (in spite of the gradual nature of the transitions) the boundaries of the three regimes. Ordinal analysis of the interdropout time intervals consistently identifies the three regimes occurring in the same parameter regions as the analysis of the intensity distribution. Simulations of the well-known time-delayed Lang-Kobayashi model are in good qualitative agreement with the observations.Peer ReviewedPostprint (published version

Experimental study of modulation waveforms for entraining the spikes emitted by a semiconductor laser with optical feedback

© 2018 [Optical Society of America]. Users may use, reuse, and build upon the article, or use the article for text or data mining, so long as such uses are for non-commercial purposes and appropriate attribution is maintained. All other rights are reserved.The entrainment phenomenon, by which an oscillator adjusts its natural rhythm to an external periodic signal, has been observed in many natural systems. Recently, attention has focused on which are the optimal conditions for achieving entrainment. Here we use a semiconductor laser with optical feedback, operating in the low-frequency fluctuations (LFFs) regime, as a testbed for a controlled entrainment experiment. In the LFF regime the laser intensity displays abrupt spikes, which can be entrained to a weak periodic signal that directly modulates the laser pump current. We compare the performance of three modulation waveforms for producing 1:1 locking (one spike is emitted in each modulation cycle), as well as higher order locking regimes. We characterize the parameter regions where high-quality locking occurs, and those where the laser emits spikes which are not entrained to the external signal. The role of the modulation amplitude and frequency, and the role of the dc value of the laser pump current (that controls the natural spike frequency) in the entrainment quality are discussed.Peer ReviewedPostprint (published version

The Italian Draft Law on the \u2018Provisions Concerning the Safeguarding of the Intangible Cultural Heritage\u2019

Intangible cultural heritage in Italy is still in need of a unified approach, capable of providing reliable criteria for identifying its assets and for indicating timescales and means by which they should be safeguarded. In the continued absence of up-to-date, ad hoc state legislation (since the content of those laws which do implement international Conventions is too generic in nature to be sufficiently effective), the Regions have proceeded to act in a somewhat scattered manner, giving rise to an extremely fragmented and very disorderly regulatory framework. The draft law N. 4486, "Provisions Concerning the Safeguarding of the Intangible Cultural Heritage", presented on 12th May 2017 at the Chamber of Deputies of the Italian Republic - as the result of the work of an interdisciplinary and inter-university research team coordinated by Marco Giampieretti, who has drafted the final text with the collaboration of Simona Pinton - seeks to fill the serious void that exists in Italian legal system by aligning it to the principles of international and European law, by redirecting the relevant State and Regional legislation, and by satisfying the fundamental requirements of the national community

Who are the visitors of the art museums: Particularities of the publics of the weekends at the Art Museum of Tigre (Argentina)

Saber quiénes son sus visitantes es una de las principales tareas de los museos en la actualidad, en la medida en que fluctúan entre ajustarse a las imposiciones del sistema capitalista y convertirse en instituciones democráticas y participativas. No obstante, este aspecto resulta aun más dificultoso en los museos de arte, en virtud de los atributos particulares de su estructura y actores. El presente trabajo tiene como objetivo aproximar algunos criterios que permitan conocer quiénes son los visitantes de los museos de arte creados en Argentina desde el inicio del nuevo milenio. Dada la magnitud del desafío, se procura, con el foco puesto en un caso particular, trazar algunos lineamientos sostenidos en los enfoques teórico-críticos aplicados a la museología y en los estudios de públicos. En cuanto a lo metodológico, se recurrió a un estudio de visitantes que apeló a orientaciones cuantitativas y cualitativas, realizado en el Museo de Arte de Tigre durante 2017, centrado en los públicos del fin de semana. Se considera que, al indagar los rasgos singulares de esta entidad patrimonial, pueden identificarse algunos indicios que permitan comenzar a trazar un perfil, tanto general como específico, de los visitantes de los museos de arte.Knowing who its visitors are is one of the main tasks of museums today, as they fluctuate between conforming to the impositions of the capitalist system and becoming democratic and participatory institutions. However, this aspect is even more difficult in the arts museums because of the particular attributes of their structure and its diverse actors. The present work has as main object to bring near some criteria that may allow to know who are the visitors of the art museums in Argentina since the beginning of the new millennium. Given the extent of the challenge, we’ll try, focusing in a particular case, draw some guidelines sustained in the theorical-critical approaches applied to museology and studies of the publics. In terms of methodology, a visitor study was carried out at the Tigre Art Museum in 2017, using both quantitative and qualitative guidelines, focusing on weekend audiences. It is considered that, when we question the singularities of this entity, there are some indications that a general and specific profile of visitors to art museums can begin to be identified.Saber quem são seus visitantes é uma das principais tarefas dos museus na atualidade, na medida em que flutuam entre amoldar-se às imposições do sistema capitalista e converter-se em instituições democráticas e participativas. Não obstante, este aspecto resulta ainda mais dificultoso nos museus de arte, devido aos atributos particulares de sua estrutura e atores. O presente trabalho tem por objetivo aproximar alguns critérios que permitam conhecer quem são os visitantes dos museus de arte criados na Argentina desde o início do novo milênio. Dada a magnitude do desafio, e com o foco posto em um caso particular, buscou-se traçar alguns lineamentos sustentados nos enfoques teórico-críticos aplicados à museologia e nos estudos de públicos. Quanto à metodologia, a pesquisa teve como base um estudo de visitantes que apelou a orientações quantitativas e qualitativas, realizado no Museu de Arte de Tigre durante o ano de 2017, focado nos públicos de fim de semana. Considera-se que, ao indagarmos os traços singulares desta entidade, podem ser identificados alguns indícios que permitam começar a esboçar um perfil, tanto geral quanto específico, dos visitantes dos museus de arte.Fil: Panozzo Zenere, Alejandra Gabriela. Universidad Nacional de Rosario. Facultad de Ciencias Políticas y Relaciones Internacionales. Instituto de Investigaciones. Centro de Investigaciones en Mediatizaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentin

Identity contemporary art museums: Between heritage and market

En los últimos años se evidencia un crecimiento exponencial de los museos de arte surgidos en ciudades periféricas que guardan una convivencia de lo local frente a lo global. Se trata de importantes colecciones dentro de vistosos espacios edilicios, que se emplazan en puntos estratégicos de las ciudades que le dan cobijo. Estas instituciones, con sus rasgos diferenciadores, invitan a mirar y consumir el arte desde un lugar distinto, y nos plantean si dentro de este binomio puede tener lugar una identidad latinoamericana. El recorrido de este artículo tiene por objetivo repasar construcciones discursivas en torno a esta temática, desde la reflexión de la propuesta del Museo de Arte Contemporáneo de Rosario, Argentina; una experiencia relevante para la cultura rosarina, en la que confluye el reuso del suelo urbano con retóricas identitarias.In recent years, it has become discernible an exponential growth of art museums in outlying cities, exposing a coexistence between the local and global spheres. Important art collections in magnificent buildings strategically placed in the cities that house them. These institutions, together with its most distinctive features, invite us to contemplate and consume art from a different perspective, but at the same time it raises the question whether the existence of a LatinAmerican identity is possible amid this coupling. The aim of this work is to revise a number of texts regarding this subject, taking as a point of departure the consideration of the proposal formulated by the Museum of Contemporary Art of Rosario, Argentina; a relevant experience for the culture of the city of Rosario, where the reuse of urban land and identitary rhetorics are joined together.Fil: Panozzo Zenere, Alejandra Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Humanidades y Artes; ArgentinaFil: Escudero, Cristina. Universidad Nacional de Avellaneda; Argentin

Effect of pulsed light on selected properties of egg white

The effect of pulsed light (from 1.75 to 31.5 J cm- 2) on selected properties of egg white (absorbance, particle size, protein fractions, free sulfhydryl content, immunoreactivity, viscosity, gelling and foaming properties) was investigated. Pulsed light induced the development of browning, the formation of large protein aggregates by disulfide exchange, and protein backbone cleavage. These structural modifications cause an increase in immunoreactivity and a decrease in gelling temperature. However, no changes in viscosity and gel strength were observed. Egg white exposed to pulsed light produced foams with higher stability. This effect was attributed to jamming of protein aggregates and fragments in the fluid interstices between bubbles. Industrial relevance Pulsed light promotes structural changes of egg white proteins modifying their functional properties. Pulsed light treatment has a good potential for successful application in improving functional properties of protein rich ingredients. \ua9 2013 Elsevier Ltd. All rights reserved

Inactivation of Polyphenoloxidase by Pulsed Light

The effect of pulsed light on the inactivation of polyphenoloxidase (PPO) in model solutions was investigated focusing on the effect of enzyme concentration and total energy dose of the treatment. PPO inactivation increased with the dose of the treatment. Complete enzyme inactivation was achieved by pulsed light doses higher than 8.75 J cm-2. At low PPO concentrations (4 to 10 U), the enzyme resulted highly inactivated by pulsed light treatment. Further increase in enzyme units determined a progressive decrease in PPO inactivation. The latter was attributed to protein structural modifications including cleavage and unfolding/aggregation phenomena. PPO amounts higher than 10 U probably favoured enzyme conformations that were less prone to intermolecular rearrangements leading to inactivation. \ua9 2013 Institute of Food Technologists\uae

Effect of ultraviolet processing on selected properties of egg white

The effect of ultraviolet processing (10.6 and 63.7 kJ m-2) on selected properties of egg white (absorbance, particle size, protein fractions, free sulfhydryl content, immunoreactivity, viscosity, gelling and foaming properties) was investigated. Ultraviolet exposure induced the development of browning, the formation of large protein aggregates by disulfide exchange, and protein backbone cleavage. However, egg white proteins were differently sensitive to UV radiation. No changes in immunoreactivity, gelling temperature and gel firmness were observed. Independently on the UV dose, light treated egg white produced foams with higher stability. This effect was attributed to protein aggregates jamming in the fluid interstices between bubbles and/or to the higher viscosity of the aqueous phase. The latter was also associated to higher foam volume. \ua9 2012 Elsevier Ltd. All rights reserved

Effect of pulsed light on structure and immunoreactivity of gluten

The effect of pulsed light (from 1.75 to 26.25 J cm(-2)) on selected properties of wheat gluten powder and aqueous suspension (absorbance, particle size and microstructure, free sulfhydryl content, protein fractions, protein electrophoretic mobility and immunoreactivity) was investigated. Gluten photoreactivity was strongly affected by hydration. While minor photo-induced structure modifications were observed in gluten powder, pulsed light induced the development of browning and promoted partial depolymerisation of hydrated gluten proteins by disulphide exchange. These changes were associated with a significant decrease in immunoreactivity, suggesting that pulsed light could be exploited to efficiently modify structure and thus functionality of gluten

Complete Sequence of the Intronless Mitochondrial Genome of the Saccharomyces cerevisiae Strain CW252

WOS:000452362800008The mitochondrial genomes of strains contain up to 13 introns. An intronless recombinant genome introduced into the nuclear background of strain W303 gave the CW252 strain, which is used to model mitochondrial respiratory pathologies. The complete sequence of this mitochondrial genome was obtained using a hybrid assembling methodology