Fractional Brownian fields, duality, and martingales

In this paper the whole family of fractional Brownian motions is constructed as a single Gaussian field indexed by time and the Hurst index simultaneously. The field has a simple covariance structure and it is related to two generalizations of fractional Brownian motion known as multifractional Brownian motions. A mistake common to the existing literature regarding multifractional Brownian motions is pointed out and corrected. The Gaussian field, due to inherited ``duality'', reveals a new way of constructing martingales associated with the odd and even part of a fractional Brownian motion and therefore of the fractional Brownian motion. The existence of those martingales and their stochastic representations is the first step to the study of natural wavelet expansions associated to those processes in the spirit of our earlier work on a construction of natural wavelets associated to Gaussian-Markov processes.Comment: Published at http://dx.doi.org/10.1214/074921706000000770 in the IMS Lecture Notes Monograph Series (http://www.imstat.org/publications/lecnotes.htm) by the Institute of Mathematical Statistics (http://www.imstat.org

Accurate Stereo Visual Odometry with Gamma Distributions

Point-based stereo visual odometry systems typically estimate the camera motion by minimizing a cost function of the projection residuals between consecutive frames. Under some mild assumptions, such minimization is equivalent to maximizing the probability of the measured residuals given a certain pose change, for which a suitable model of the error distribution (sensor model) becomes of capital importance in order to obtain accurate results. This paper proposes a robust probabilistic model for projection errors, based on real world data. For that, we argue that projection distances follow Gamma distributions, and hence, the introduction of these models in a probabilistic formulation of the motion estimation process increases both precision and accuracy. Our approach has been validated through a series of experiments with both synthetic and real data, revealing an improvement in accuracy while not increasing the computational burden.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Project "PROMOVE: Advances in mobile robotics for promoting independent life of elders", funded by the Spanish Government and the "European Regional Development Fund ERDF" under contract DPI2014-55826-R

Stokes polarimetry and magnetometry using a thermal Rb vapour in the Voigt geometry with large magnetic field

We present investigations of magneto-optical phenomena using a $^{87}$Rb thermal vapour in large magnetic fields. At this point, in the hyperfine Paschen-Back regime, optical transitions can be separated by more than their Doppler-broadened linewidth, providing a high level of control over the atomic system and a simpler theoretical model for studying atom-light-magnetic field interactions. In this context, we study the spectra of $^{87}$Rb at magnetic fields of $0.4~$T and $1.5~$T in the Voigt geometry. In both cases we find excellent agreement between experimental and theoretical absorption spectra. With the $1.5~$T field we also study polarisation changes induced in the light by the atoms subject to a large magnetic field. Using this approach, we consider the practical applications of our system as a vector magnetometer. We present a scheme that eliminates most sources of systematic errors in the measurement of the field strength by using pairs of transitions that cancel excited-state terms in the energy shifts. Finally, we extend the concepts and ideas investigated to an application in precision thermometry. We discuss how good understanding of the spectra and the magnetic field strength potentially allow detection of small differences in different spectral features, which could then be traced to the effect of the Boltzmann factor, $k_{\rm{B}}T$, on the atomic populations

The NADPH-Dependent thioredoxin reductase C-2-Cys peroxiredoxin redox system modulates the activity of thioredoxin x in arabidopsis chloroplasts

The chloroplast redox network is composed of a complex set of thioredoxins (Trxs), reduced by ferredoxin (Fdx) via a Fdx-dependent Trx reductase (FTR), and an NADPH-dependent Trx reductase with a joint Trx domain, NTRC, which efficiently reduces 2-Cys peroxiredoxins (2-Cys Prxs). Recently, it was proposed that the redox balance of 2-Cys Prxs maintains the redox state of f-type Trxs, thus allowing the proper redox regulation of Calvin-Benson cycle enzymes such as fructose 1,6-bisphosphatase (FBPase). Here, we have addressed whether the action of 2-Cys Prxs is also exerted on Trx x. To that end, an Arabidopsis thaliana quadruple mutant, ntrc-trxx-δ "2cp, which is knocked out for NTRC and Trx x, and contains severely decreased levels of 2-Cys Prxs, was generated. In contrast to ntrc-trxx, which showed a severe growth inhibition phenotype and poor photosynthetic performance, the ntrc-trxx-δ "2cp mutant showed a significant recovery of growth rate and photosynthetic efficiency, indicating that the content of 2-Cys Prxs is critical for the performance of plants lacking both NTRC and Trx x. Light-dependent reduction of FBPase was severely impaired in mutant plants lacking NTRC or NTRC plus Trx x, despite the fact that neither NTRC nor Trx x is an effective reductant of this enzyme. However, FBPase reduction was recovered in the ntrc-trxx-δ "2cp mutant. Our results show that the redox balance of 2-Cys Prxs, which is mostly dependent on NTRC, modulates the activity of Trx x in a similar way as f-type Trxs, thus suggesting that the activity of these Trxs is highly interconnected.Ministerio de Economía y Competitividad BIO2017-85195-C2-1-

En un mundo nuevo: patrimonio, identidades y turismo en las postales del Festival de Eurovisión

Desde la XV Edición del Festival de la Canción de Eurovisión (año 1970), es una popular costumbre la emisión de breves vídeos que preceden a cada actuación. Conocidos como postales, estos cortos ofrecen, generalmente, narrativas patrimoniales tanto del país sede del certamen como de los distintos participantes. A partir de una muestra de 437 postales, emitidas en los festivales celebrados desde el año 2000 hasta la edición de 2021, hemos realizado un análisis cualitativo del papel que juega el patrimonio en estos vídeos. Tanto desde un enfoque identitario/nacionalista, como desde un uso puramente de mercado a través del turismo, las famosas postales exhiben un tímido desplazamiento en las nociones de patrimonio y nuevas formas de conceptualizar la experiencia turísticaSince the 15th Eurovision Song Contest (1970), short videos preceding each performance have become popular within the contest. Known as postcards, these short films generally offer heritage narratives of both the host country and participating countries. Based on a sample of 437 postcards, broadcast at the festivals from 2000 to the 2021, we have carried out a qualitative analysis of the role played by heritage in these videos. Both from an identity/nationalist approach and from a purely market use through tourism, the famous postcards exhibit a timid shift in the notions of heritage and new ways of conceptualising the tourist experience

La potencialidad dialéctico-crítica de construcción de conciencia histórica

The conscience of a person is a condensation of the social conscience of the historical moment of his/her constitution. The conscience is formed with referents that derive from diverse manners of appropriation of the real, which turn into a condition of incorporating new referents, which are translated into its logic of operation. The conscience is dialectical as dialectical is the reality that represents. The mutability of the real and of its representation in the conscience, places critical dialectics in a relation of correspondence to the real with thinking and postulates the possibility of social knowledge for the intentional empowerment of the real.    La conciencia de un sujeto es condensación de la conciencia social del momento histórico de su constitución. La conciencia se forma con referentes de diversos modos de apropiación de lo real que se convierten en condición de incorporación de nuevos referentes, los cuales son traducidos a su lógica de operación. La conciencia es dialéctica como dialéctica es la realidad que se representa en ella. La mutabilidad de lo real y de su representación en la conciencia, coloca a la dialéctica crítica en una relación de correspondencia a lo real con lo pensado y postula la posibilidad constructora de conocimiento social para la potenciación intencional de lo real.  

Politiques de protection des espaces naturels

Classer près du cinquième du territoire andalou au titre d'espaces naturels protégés a constitué pour l'Administration autonome une décision risquée et de très vaste envergure. Doter de tels espaces d'un ensemble de réglementations souples et opérationnelles est apparu comme un défi, de tels instruments étant considérés comme des facteurs de dynamisation et comme des moyens de lutter contre la marginalité sociale et économique des populations concernées. Preservation policies of natural spaces. The case of Andalousia. Almost one fifth of the andalousian territory has been classified as preserved naturel space. For the administration of the autonomous community, it was a risky decision and a broad prospect. Providing such spaces with a set of rather flexibles norms was a challenge. Such tools are considered as dynamic incentives liable to fight socio-economic marginality of the inhabitants. Politícas de espacios naturales protegidos : el marco andaluz. La declaración de cerca de una quinta parte del territorio andaluz como Espacio Natural Protegido ha constituido una decisión arriesgada y de enorme embergatura acometida por la Administración Autonómica. La tarea de dotar de un cuerpo normativo y de una agilidad operativa a tales espacios protegidos aparece como un reto, ya que se consideran como factores de dinamización y superación de la marginalidad social y económica en que se hayan inmersas las poblaciones afectadas