Novel whitening approaches in functional settings

Whitening is a critical normalization method to enhance statistical reduction via reparametrization to unit covariance. This article introduces the notion of whitening for random functions assumed to reside in a real separable Hilbert space. We compare the properties of different whitening transformations stemming from the factorization of a bounded precision operator under a particular geometrical structure. The practical performance of the estimators is shown in a simulation study, providing helpful insights into their optimization. Computational algorithms for the estimation of the proposed whitening transformations in terms of basis expansions of a functional data set are also provided.Ministry of Science and Innovation, Spain (MICINN) Instituto de Salud Carlos III Spanish Government PID2020-113961GB-I00Methusalem, Vlaamse regerin

Magnetic Field Effects on the Head Structure of Protostellar Jets

We present the results of 3-D SPMHD numerical simulations of supermagnetosonic, overdense, radiatively cooling jets. Two initial magnetic configurations are considered: (i) a helical and (ii) a longitudinal field. We find that magnetic fields have important effects on the dynamics and structure of radiative cooling jets, especially at the head. The presence of a helical field suppresses the formation of the clumpy structure which is found to develop at the head of purely hydrodynamical jets. On the other hand, a cooling jet embedded in a longitudinal magnetic field retains clumpy morphology at its head. This fragmented structure resembles the knotty pattern commonly observed in HH objects behind the bow shocks of HH jets. This suggests that a strong (equipartition) helical magnetic field configuration is ruled out at the jet head. Therefore, if strong magnetic fields are present, they are probably predominantly longitudinal in those regions. In both magnetic configurations, we find that the confining pressure of the cocoon is able to excite short-wavelength MHD K-H pinch modes that drive low-amplitude internal shocks along the beam. These shocks are not strong however, and it likely that they could only play a secondary role in the formation of the bright knots observed in HH jets.Comment: 14 pages, 2 Gif figures, uses aasms4.sty. Also available on the web page http://www.iagusp.usp.br/preprints/preprint.html. To appear in The Astrophysical Journal Letter

Proyecto de transporte y distribución de energía eléctrica a una zona industrial del Alt Berguedà

El objetivo de este proyecto es la construcción de una línea eléctrica de 110 kV de simple circuito, cuya finalidad es suministrar energía eléctrica a un complejo industrial de nueva construcción, con un consumo de 50 MVA de potencia. Con el presente documento se pretenden establecer las características a las que habrá que ajustarse las instalaciones, siempre de acuerdo con lo que determinen los vigentes Reglamentos e Instrucciones Técnicas Complementarias, para así obtener la Aprobación de Proyecto correspondiente

Knee flexion of saxophone players anticipates tonal context of music

Music performance requires high levels of motor control. Professional musicians use body movements not only to accomplish and help technical efficiency, but to shape expressive interpretation. Here, we recorded motion and audio data of twenty participants performing four musical fragments varying in the degree of technical difficulty to analyze how knee flexion is employed by expert saxophone players. Using a computational model of the auditory periphery, we extracted emergent acoustical properties of sound to inference critical cognitive patterns of music processing and relate them to motion data. Results showed that knee flexion is causally linked to tone expectations and correlated to rhythmical density, suggesting that this gesture is associated with expressive and facilitative purposes. Furthermore, when instructed to play immobile, participants tended to microflex (>1 Hz) more frequently compared to when playing expressively, possibly indicating a natural urge to move to the music. These results underline the robustness of body movement in musical performance, providing valuable insights for the understanding of communicative processes, and development of motor learning cues.Grant 2020.05257.BD of the Portuguese Foundation for Science and TechnologyFSE programme through Programa Operacional Regional NorteFlemish Government, the project FQM-307 of the Government of Andalusia (SpainProject PID2020-113961GB-I00 of the Spanish Ministry of Science and Innovation (also supported by the FEDER programme).Consejería de Conocimiento, Investigación y Universidad, Junta de Andalucía (Spain)FEDER programme for the project A-FQM-66-UGR20IMAG-María de Maeztu grant CEX2020-001105-M/AEI/ 10.13039/50110001103

Col·laboració a l'estudi de les plantes invasores del Parc Natural de l'Alt Pirineu : cartografia de detall i recull de mesures de gestió

La intrusió de les plantes exòtiques invasores en els espais naturals protegits de Catalunya s'ha convertit en un problema de primer ordre. En alguns d'aquests espais fa temps que s'han començat a gestionar aquestes espècies exòtiques. No és el cas del PNAP, que degut a la seva recent creació, encara no ha pogut tractar a fons aquesta problemàtica. Per tant, amb el present estudi s'ha treballat en conèixer la distribució d'aquetes espècies en el Parc i en crear una base de referència. La major part de les plantes trobades estan situades en llocs on la pressió humana es molt forta. Un cop establertes prop de les àrees més antropitzades, aquestes espècies es disseminen pel territori aprofitant-se de les zones degradades per establir-se. Per aquesta raó, també es proposen les mesures d'actuació més adients per a gestionar aquestes espècies en el territori de l'Alt Pirineu, prenent com a referent les actuacions que es duen a terme avui arreu del món.La intrusión de las plantas exóticas invasoras en los espacios naturales protegidos de Catalunya se ha convertido en un problema de primer orden. En algunos de estos espacios hace tiempo que se han comenzado a gestionar estas especies exóticas. No es el caso del PNAP, que debido a su reciente creación aún no ha podido tratar a fondo esta problemática. Por tanto, con el presente estudio se ha trabajado en conocer la distribución de estas especies en el Parque y crear una base de datos de referencia. La mayor parte de las plantas encontrada están situadas en sitios donde la presión humana es muy fuerte. Una vez establecidas cerca de las zonas más antropizadas, estas especies se diseminan por el territorio aprovechándose de las zonas degradadas para establecerse. Por este motivo, también se proponen las mesuras de actuación más adecuadas para gestionar estas especies en el territorio del Alto Pirineo, tomando como referente las actuaciones que se llevan a cabo alrededor del mundo.The intrusion of invasive alien plants in protected natural areas in Catalonia has become a major problem. In some of these areas have long since begun to manage these exotic species. It is not the case of PNAP, which due to its recent creation, has not yet been thoroughly treat this problem. Therefore, this study has worked in the distribution of modules in this species in the Park and create a baseline. Most of the plants found are located in places where human pressure is very strong. Once established near anthropogenically-impacted environments, these species are spread throughout the region taking advantage of degraded areas to settle. For this reason, we also propose the most appropriate performance measures to manage these species in the territory of the High Pyrenees, taking as reference the actions are carried out worldwide today

Caught in the act: cluster 'k+a' galaxies as a link between spirals and S0s

We use integral field spectroscopy of 13 disc galaxies in the cluster AC114 at z ∼ 0.31 in an attempt to disentangle the physical processes responsible for the transformation of spiral galaxies in clusters. Our sample is selected to display a dominant young stellar population, as indicated by strong Hδ absorption lines in their integrated spectra. Most of our galaxies lack the [O ii]λ3727 emission line, and hence ongoing star formation. They therefore possess ‘k+a’ spectra, indicative of a recent truncation of star formation, possibly preceded by a starburst. Discy ‘k+a’ galaxies are a promising candidate for the intermediate stage of the transformation from star-forming spiral galaxies to passive S0s. Our observations allow us to study the spatial distributions and the kinematics of the different stellar populations within the galaxies. We used three different indicators to evaluate the presence of a young population: the equivalent width of Hδ, the luminosity-weighted fraction of A stars, and the fraction of the galaxy light attributable to simple stellar populations with ages between 0.5 and 1.5 Gyr. We find a mixture of behaviours, but are able to show that in most of the galaxies the last episode of star formation occurred in an extended disc, similar to preceding generations of stars, though somewhat more centrally concentrated. We thus exclude nuclear starbursts and violent gravitational interactions as causes of the star formation truncation. Gentler mechanisms, such as ram-pressure stripping or weak galaxy–galaxy interactions, appear to be responsible for ending star formation in these intermediate-redshift cluster disc galaxies

The Gemini NICI Planet-Finding Campaign

Our team is carrying out a multi-year observing program to directly image and characterize young extrasolar planets using the Near-Infrared Coronagraphic Imager (NICI) on the Gemini-South 8.1-meter telescope. NICI is the first instrument on a large telescope designed from the outset for high-contrast imaging, comprising a high-performance curvature adaptive optics system with a simultaneous dual-channel coronagraphic imager. Combined with state-of-the-art observing methods and data processing, NICI typically achieves ~2 magnitudes better contrast compared to previous ground-based or space-based programs, at separations inside of ~2 arcsec. In preparation for the Campaign, we carried out efforts to identify previously unrecognized young stars, to rigorously construct our observing strategy, and to optimize the combination of angular and spectral differential imaging. The Planet-Finding Campaign is in its second year, with first-epoch imaging of 174 stars already obtained out of a total sample of 300 stars. We describe the Campaign's goals, design, implementation, performance, and preliminary results. The NICI Campaign represents the largest and most sensitive imaging survey to date for massive (~1 Mjup) planets around other stars. Upon completion, the Campaign will establish the best measurements to date on the properties of young gas-giant planets at ~5-10 AU separations. Finally, Campaign discoveries will be well-suited to long-term orbital monitoring and detailed spectrophotometric followup with next-generation planet-finding instruments.Comment: Proceedings of the SPIE, vol 7736 (Advances in Adaptive Optics, San Diego, CA, June 2010 meeting), in pres

The Gemini NICI Planet-Finding Campaign: The Frequency of Giant Planets Around Debris Disk Stars

We have completed a high-contrast direct imaging survey for giant planets around 57 debris disk stars as part of the Gemini NICI Planet-Finding Campaign. We achieved median H-band contrasts of 12.4 mag at 0.5" and 14.1 mag at 1" separation. Follow-up observations of the 66 candidates with projected separation < 500 AU show that all of them are background objects. To establish statistical constraints on the underlying giant planet population based on our imaging data, we have developed a new Bayesian formalism that incorporates (1) non-detections, (2) single-epoch candidates, (3) astrometric and (4) photometric information, and (5) the possibility of multiple planets per star to constrain the planet population. Our formalism allows us to include in our analysis the previously known Beta Pictoris and the HR 8799 planets. Our results show at 95% confidence that 5MJup planet beyond 80 AU, and 3MJup planet outside of 40 AU, based on hot-start evolutionary models. We model the population of directly-imaged planets as d^2N/dMda ~ m^alpha a^beta, where m is planet mass and a is orbital semi-major axis (with a maximum value of amax). We find that beta 1.7. Likewise, we find that beta < -0.8 and/or amax < 200 AU. If we ignore the Beta Pic and HR 8799 planets (should they belong to a rare and distinct group), we find that 3MJup planet beyond 10 AU, and beta < -0.8 and/or alpha < -1.5. Our Bayesian constraints are not strong enough to reveal any dependence of the planet frequency on stellar host mass. Studies of transition disks have suggested that about 20% of stars are undergoing planet formation; our non-detections at large separations show that planets with orbital separation > 40 AU and planet masses > 3 MJup do not carve the central holes in these disks.Comment: Accepted to ApJ on June 24, 2013. 67 pages, 17 figures, 12 table