Search results for " transitions"
showing 10 items of 196 documents
Geometry of quantum phase transitions
2020
In this article we provide a review of geometrical methods employed in the analysis of quantum phase transitions and non-equilibrium dissipative phase transitions. After a pedagogical introduction to geometric phases and geometric information in the characterisation of quantum phase transitions, we describe recent developments of geometrical approaches based on mixed-state generalisation of the Berry-phase, i.e. the Uhlmann geometric phase, for the investigation of non-equilibrium steady-state quantum phase transitions (NESS-QPTs ). Equilibrium phase transitions fall invariably into two markedly non-overlapping categories: classical phase transitions and quantum phase transitions, whereas i…
Ultrafast critical ground state preparation via bang-bang protocols
2020
The fast and faithful preparation of the ground state of quantum systems is a challenging task but crucial for several applications in the realm of quantum-based technologies. Decoherence poses a limit to the maximum time-window allowed to an experiment to faithfully achieve such desired states. This is of particular significance in critical systems, where the vanishing energy gap challenges an adiabatic ground state preparation. We show that a bang-bang protocol, consisting of a time evolution under two different values of an externally tunable parameter, allows for a high-fidelity ground state preparation in evolution times no longer than those required by the application of standard opti…
A BADER’S TOPOLOGICAL APPROACH FOR THE CHARACTERIZATION OF PRESSURE INDUCED PHASE TRANSITIONS
2012
Transformando las prácticas de evaluación en las agencias de innovación para fomentar transiciones hacia la sostenibilidad
2019
The aim of the study is to identify different styles and practices for evaluation of innovation policies based on different orientations, focusing on the case of the paradigm of transformative change to foster transitions towards sustainability, and the problems associated with its application. The study is exploratory, and it uses public funding agencies for innovation as strategic research settings. Based on the information provided by the experience of an international consortium participated by funding agencies from different countries, the main concepts and problems presented in the theoretical debate are illustrated. Finally, the main contributions of the study to the theory and pract…
Do you study or work? The decision making in the training pathways of young people
2017
Este trabajo aborda el análisis de los discursos de los y las jóvenes en la toma de decisiones sobre sus itinerarios formativos y las transiciones escolares y entre escuela y trabajo. A partir de las entrevistas a jóvenes en dos proyectos de investigación, uno en itinerarios considerados como de “fracaso escolar y abandono prematuro” (educación obligatoria), y otro en itinerarios considerados de “éxito” (hacia la educación superior) pretendemos aproximarnos a los factores que influyen y dan sentido a las decisiones que toma el alumnado en sus diferentes posibilidades académicas. En este marco, la relación pedagógica se muestra como un elemento clave de vinculación con el centro escolar. Sin…
The Expanding Constellation of Histone Post-Translational Modifications in the Epigenetic Landscape
2021
The emergence of a nucleosome-based chromatin structure accompanied the evolutionary transition from prokaryotes to eukaryotes. In this scenario, histones became the heart of the complex and precisely timed coordination between chromatin architecture and functions during adaptive responses to environmental influence by means of epigenetic mechanisms. Notably, such an epigenetic machinery involves an overwhelming number of post-translational modifications at multiple residues of core and linker histones. This review aims to comprehensively describe old and recent evidence in this exciting field of research. In particular, histone post-translational modification establishing/removal mechanism…
Much more than a clasp: Evolutionary pattern of amplexus diversity in anurans
2019
ABSTRACTThe evolution and diversification of animal reproductive modes have been pivotal questions in behavioral ecology. Amphibians present the highest diversity of reproductive modes among vertebrates, involving various behavioral, physiological and morphological traits. One of such features is the amplexus, the clasp or embrace of males on females during reproduction, which is almost universal to anurans. Hypotheses about the origin amplexus are limited and have not been thoroughly tested, nor had they taken into account evolutionary relationships in most comparative studies. However, these considerations are crucial to understand the evolution of reproductive modes. Here, using an evolu…
Ventastega curonica and the origin of tetrapod morphology.
2008
The gap in our understanding of the evolutionary transition from fish to tetrapod is beginning to close thanks to the discovery of new intermediate forms such as Tiktaalik roseae. Here we narrow it further by presenting the skull, exceptionally preserved braincase, shoulder girdle and partial pelvis of Ventastega curonica from the Late Devonian of Latvia, a transitional intermediate form between the 'elpistostegids' Panderichthys and Tiktaalik and the Devonian tetrapods (limbed vertebrates) Acanthostega and Ichthyostega. Ventastega is the most primitive Devonian tetrapod represented by extensive remains, and casts light on a part of the phylogeny otherwise only represented by fragmentary ta…
Exploring the contribution of grassroots innovations to justice: using the capability approach to normatively address bottom-up sustainable transitio…
2020
There is growing interest in the potential of grassroots innovations for the transition towards more just and sustainable societies. Nevertheless, there is lack of clear normative discussion regarding these processes. The paper strives to propose and test a framework that enables an analysis of how and in which sense specific grassroots innovation processes may be contributing to the construction of more just societies. To this end, we connect elements of the multi-level perspective on sociotechnical transitions (frequently used in the analysis of grassroots innovations) with elements of the capability approach, which offers a multi-dimensional perspective to justice. The framework is used …
Finite-size effects in dynamics of zero-range processes
2010
The finite-size effects prominent in zero-range processes exhibiting a condensation transition are studied by using continuous-time Monte Carlo simulations. We observe that, well above the thermodynamic critical point, both static and dynamic properties display fluid-like behavior up to a density {\rho}c (L), which is the finite-size counterpart of the critical density {\rho}c = {\rho}c (L \rightarrow \infty). We determine this density from the cross-over behavior of the average size of the largest cluster. We then show that several dynamical characteristics undergo a qualitative change at this density. In particular, the size distribution of the largest cluster at the moment of relocation,…