Interface Fluctuations, Burgers Equations, and Coarsening under Shear

We consider the interplay of thermal fluctuations and shear on the surface of the domains in various systems coarsening under an imposed shear flow. These include systems with nonconserved and conserved dynamics, and a conserved order parameter advected by a fluid whose velocity field satisfies the Navier-Stokes equation. In each case the equation of motion for the interface height reduces to an anisotropic Burgers equation. The scaling exponents that describe the growth and coarsening of the interface are calculated exactly in any dimension in the case of conserved and nonconserved dynamics. For a fluid-advected conserved order parameter we determine the exponents, but we are unable to build a consistent perturbative expansion to support their validity.Comment: 10 RevTeX pages, 2 eps figure

La evolución del instrumentista: una trayectoria continua

This article proposes to identify the key milestones that influenced the instrumentalist performance, throughout the twentieth century until nowadays. In a certain moment of the western music history, excluding henceforth unwritten instrumental music, the instrumentalist needed to incorporate elements related with other arts and/or others disparate fields, which in some way come together on the performance, beyond the enlargement of his functions and instrumental musical techniques. This evolution has broken away from the traditional performance – the act of the musician taking the stage to reproduce a musical text – creating new multidisciplinary demands on performers. These new features became a requirement for the interpreters, as well as a source of creativity for composers and creators. As a consequence, the technical mastery of instruments and of musical theory, became insufficient due to the enlarged scope requirements of certain concepts and artistic creations.Este artículo propone identificar los hitos fundamentales que influenciaron la interpretación instrumental, desde el siglo XX hasta nuestros días. En algún momento de la historia de la música occidental, excluyendo la música instrumental no escrita de ahora en adelante, el instrumentista necesitó incorporar elementos relacionados con otras artes o campos, uniéndose en cierta forma en la interpretación, más allá de la expansión de sus funciones y técnicas instrumentales. Esta evolución ha roto con la interpretación tradicional ‐ el acto del músico salir al escenario a reproducir un texto musical ‐ creando nuevas exigencias multidisciplinares en los ejecutantes. Estas nuevas características se convirtieron en requisitos para los intérpretes, además de una fuente de creatividad para los compositores y creadores. Como consecuencia, el dominio técnico del instrumento y/o teoría musical pasó a ser insuficiente debido al amplio abanico de requisitos en ciertos conceptos y creaciones artísticas.info:eu-repo/semantics/publishedVersio

Anamorfoses artísticas na música: a mediação transformadora da média-arte digital na perceção do artista e da performance musical

A música e a tecnologia têm experienciado, desde há séculos, uma coabitação e um desenvolvimento mútuo constante na nossa sociedade, o qual tem possibilitado aos músicos instrumentistas, não só a oportunidade de evoluírem os seus instrumentos, como também a sua performance. No que concerne à música em específico, Irving Godt (2005) afirma que não há conhecimento de sociedade alguma que tenha existido, ou que exista, sem música. Tal afirmação espelha bem a importância desta nas sociedades, desempenhando um papel de relevância sobre vários aspetos, sejam eles de cariz artístico, festivo, fúnebre, ou noutros enquadramentos. Na realidade, a música e a tecnologia vivem numa simbiose e com uma dinâmica particular, na qual a tecnologia fornece meios para que a música evolua, mas, por sua vez, a música também vai criando necessidades e fomentando o desenvolvimento tecnológico. Inerentemente a esta evolução conjunta e consoante os espaços temporais em que acontece, o papel dos músicos vai-se alterando espontaneamente por adaptação. É uma destas alterações, num destes timings, que é aqui investigada, nomeadamente a influência que a média-arte digital exerceu/exerce na música, sob o ponto de vista do músico instrumentista erudito de tradição ocidental escrita e, em particular, o ponto de vista do próprio autor enquanto clarinetista. Este, que vinha já observando ampliações nas suas responsabilidades enquanto intérprete - mais propriamente através de adições cénicas, físicas, acústicas, entre outras – viu-as serem aumentadas de forma mais acentuada através da junção com os canais média digitais. Sumariando, o presente documento é o resultado investigativo da forma e das implicações que este desenvolvimento relacional trouxe aos instrumentistas. Para o efeito, foi observada e identificada a performance musical instrumental tradicional, a sua evolução mediante diversos pontos de vista entre os agentes envolvidos, a evolução notacional, a evolução conceptual, a adição tecnológica, entre outros aspetos, tudo isto com o objetivo de identificar e diferenciar influências. Foram também elaborados três artefactos que explorassem ambas as áreas – média-arte digital e música –, aproveitando a formação e experiência profissional do autor enquanto instrumentista e, também, como forma geradora de dados para investigação proposta.Music and technology have been experiencing for centuries a mutual and constant cohabitation and development in our society, which has allowed instrumental musicians not only the opportunity to evolve their instruments but also their performance. Concerning music in particular, Irving Godt (2005) states that there is no society that has existed or exists without music. This reflects its importance in all societies, playing a role of relevance in various aspects, whether artistic, festive, memorial, or in other contexts. In fact, music and technology live in a symbiosis with a particular dynamic, in which technology provides means for music to evolve, but music also creates needs fostering technological development. Inherently to this joint evolution, and depending on the timings in which it happens, the role of musicians is being changed spontaneously, by adaptation. It is one of these alterations, in one of these timings, that is researched here, namely, the influence that new art media exerted/exercises in music, under the point of view of the erudite instrumentalist musician of western written tradition and, in particular, de point of view of the author as a clarinetist. The latter, who had already been observing enlargements in his responsibilities as a performer - more precisely through scenic, physical and acoustic additions, among others - saw these enlargements increase through the junction with new media channels. Summarizing, this paper is the research result of the form and implications that this relational development has brought to instrumentalists. To this end, traditional instrumental music performance was observed and identified, as well as its evolution through various points of view, including notational evolution, conceptual evolution, technological addition, among others, in order to identify and differentiate influences. Three artifacts were also elaborated to explore both areas - new media art and music -, taking advantage of the author's training and professional experience as an instrumentalist and, also, as a way to generate data for the proposed research

The protein folding transition state: Insights from kinetics and thermodynamics

We perform extensive lattice Monte Carlo simulations of protein folding to construct and compare the equilibrium and the kinetic transition state ensembles of a model protein that folds to the native state with two-state kinetics. The kinetic definition of the transition state is based on the folding probability analysis method, and therefore on the selection of conformations with 0.4<Pfold<0.6, while for the equilibrium characterization we consider conformations for which the evaluated values of several reaction coordinates correspond to the maximum of the free energy measured as a function of those reaction coordinates. Our results reveal a high degree of structural similarity between the ensembles determined by the two methods. However, the folding probability distribution of the conformations belonging to our definition of the equilibrium transition state (0.2<Pfold<0.8) is broader than that displayed by the kinetic transition state

Major events that changed the instrumentalists’ performance

This article proposes to identify aesthetic currents and key events that affected music instrumentalists over the last 100 years - approximately - as well as to characterize new outcomes in music performance. The aesthetical, technical, and compositional evolution of music influenced and changed the traditional conception of the performance – that of a musician taking to the stage using only his instrument, performing an interpretation of a musical score, in a unidirectional relationship with the audience – to a multidisciplinary concept. This generalised evolution, brought new demands to the instrumentalists, who had to adapt and improve, practically autonomously. The increase of multidisciplinarity, fostered creativity, which in turn gave rise to new techniques, both in interpretation and in musical writing. In order to focus the article, it will be centred on traditional musical instruments players, and excludes instrumental music of oral and/or improvised tradition, as well as vocal interpreters.info:eu-repo/semantics/publishedVersio

Post-modern Auschwitz: action or abstention?

Auschwitz do Pós-Moderno é uma instalação cinemática interativa que oferece ao visitante a possibilidade de interagir com vídeo e som, através da deteção da posição relativa do espectador. A instalação foi construída sobre um sistema informático dotado de uma webcam, com código desenvolvido em Processing 3, que controla ainda a reprodução de vídeo e música. A intenção da obra de arte é estimular a reflexão estabelecendo conexões entre a sociedade moderna e os campos de concentração nazis, nomeadamente através da comparação das atrocidades que aconteceram e ainda acontecem nos nossos dias.Auschwitz do Pós-Moderno is an interactive cinematic installation o"ering the visitor the possibility to interact with video and sound by detecting the viewer’s relative position. The installation relies upon a computer system using a webcam, code developed using Processing 3, which also controls video and music playback. The artwork’s intention is to foster re!ection be establishing connections between our modern day society and Nazi concentration camps, namely by comparing the human-driven atrocities that happened and are still happening.info:eu-repo/semantics/publishedVersio

Why Do Protein Folding Rates Correlate with Metrics of Native Topology?

For almost 15 years, the experimental correlation between protein folding rates and the contact order parameter has been under scrutiny. Here, we use a simple simulation model combined with a native-centric interaction potential to investigate the physical roots of this empirical observation. We simulate a large set of circular permutants, thus eliminating dependencies of the folding rate on other protein properties (e.g. stability). We show that the rate-contact order correlation is a consequence of the fact that, in high contact order structures, the contact order of the transition state ensemble closely mirrors the contact order of the native state. This happens because, in these structures, the native topology is represented in the transition state through the formation of a network of tertiary interactions that are distinctively long-ranged

TrajPy: empowering feature engineering for trajectory analysis across domains

Trajectories, sequentially measured quantities that form a path, are an important presence in many different fields, from hadronic beams in physics to electrocardiograms in medicine. Trajectory anal-ysis requires the quantification and classification of curves either using statistical descriptors or physics-based features. To date, there is no extensive and user-friendly package for trajectory anal-ysis available, despite its importance and potential application across domains. We developed a free open-source python package named TrajPy as a complementary tool to empower trajectory analysis. The package showcases a friendly graphic user interface and provides a set of physical descriptors that help characterizing these intricate structures. In combina-tion with image analysis, it was already successfully applied to the study of mitochondrial motility in neuroblastoma cell lines and to the analysis of in silico models for cell migration. The TrajPy package was developed in Python 3 and released under the GNU GPL-3 license. Easy installation is available through PyPi and the development source code can be found in the repository https://github.com/ocbe-uio/TrajPy/. The package release is automatically archived under the DOI 10.5281/zenodo.3656044.Comment: 4 pages, 1 figur

Dynamics and delocalisation transition for an interface driven by a uniform shear flow

We study the effect of a uniform shear flow on an interface separating the two broken-symmetry ordered phases of a two-dimensional system with nonconserved scalar order parameter. The interface, initially flat and perpendicular to the flow, is distorted by the shear flow. We show that there is a critical shear rate, \gamma_c, proportional to 1/L^2, (where L is the system width perpendicular to the flow) below which the interface can sustain the shear. In this regime the countermotion of the interface under its curvature balances the shear flow, and the stretched interface stabilizes into a time-independent shape whose form we determine analytically. For \gamma > \gamma_c, the interface acquires a non-zero velocity, whose profile is shown to reach a time-independent limit which we determine exactly. The analytical results are checked by numerical integration of the equations of motion.Comment: 5 page