Geometric Hermite interpolation by rational curves of constant width

A constructive characterization of the support function for a rationally parameterized curve of constant width is given. In addition, a Hermite interpolation problem for such kind of curves is solved, which yields a method to determine a rational curve of constant width that passes through a set of free points with the corresponding tangent directions. Finally, the case of piecewise rational support functions is considered, which increases the design freedom. The procedure is presented in the general case of hedgehogs of constant width taking the advantage of projective hedgehogs, so that some constraints must be taken to ensure convexity of the desired curve.Funding for the other authors not affiliated with BCAM: Grant PID2021-124577NBI00 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”. Project PID2019-104927GB-C21 funded by MCIN/AEI/10.13039/501100011033. Project UJI-B2022-19 funded by Universitat Jaume I. Project CIAICO/2021/180 funded by Generalitat Valenciana

Nambu-Poisson manifolds and associated n-ary Lie algebroids

We introduce an n-ary Lie algebroid canonically associated with a Nambu-Poisson manifold. We also prove that every Nambu-Poisson bracket defined on functions is induced by some differential operator on the exterior algebra, and characterize such operators. Some physical examples are presented

Translational Retinal Research and Therapies.

The following review summarizes the state of the art in representative aspects of gene therapy/translational medicine and evolves from a symposium held at the School of Veterinary Medicine, University of Pennsylvania on November 16, 2017 honoring Dr. Gustavo Aguirre, recipient of ARVO's 2017 Proctor Medal. Focusing on the retina, speakers highlighted current work on moving therapies for inherited retinal degenerative diseases from the laboratory bench to the clinic

Italian Science Case for ALMA Band 2+3

The Premiale Project "Science and Technology in Italy for the upgraded ALMA Observatory - iALMA" has the goal of strengthening the scientific, technological and industrial Italian contribution to the Atacama Large Millimeter/submillimeter Array (ALMA), the largest ground based international infrastructure for the study of the Universe in the microwave. One of the main objectives of the Science Working Group (SWG) inside iALMA, the Work Package 1, is to develop the Italian contribution to the Science Case for the ALMA Band 2 or Band 2+3 receiver. ALMA Band 2 receiver spans from ~67 GHz (bounded by an opaque line complex of ozone lines) up to 90 GHz which overlaps with the lower frequency end of ALMA Band 3. Receiver technology has advanced since the original definition of the ALMA frequency bands. It is now feasible to produce a single receiver which could cover the whole frequency range from 67 GHz to 116 GHz, encompassing Band 2 and Band 3 in a single receiver cartridge, a so called Band 2+3 system. In addition, upgrades of the ALMA system are now foreseen that should double the bandwidth to 16 GHz. The science drivers discussed below therefore also discuss the advantages of these two enhancements over the originally foreseen Band 2 system.Comment: 43 pages, 21 figure

Práctica deportiva, condición física y salud en la adolescencia: Proyecto DADOS

Introducción: La condición física (CF) es un potente marcador de salud durante la adolescencia. La participación en actividades deportivas organizadas es la forma más común de actividad física, reportando múltiples beneficios para la salud. La contribución de la práctica deportiva a la CF depende de las características de dicha práctica. El objetivo de nuestro estudio fue examinar la asociación entre las especialidades deportivas y la CF en atletas adolescentes. Métodos: 164 atletas (101 chicos) de 13.9±0.3 años, participantes del Proyecto DADOS, fueron incluidos en el análisis. La fuerza muscular se evaluó con las pruebas de fuerza de prensión manual y salto horizontal. La velocidad-agilidad se evaluó mediante el test 4x10m. La resistencia cardiorrespiratoria se evaluó con el test de ida y vuelta de 20m. Los participantes autoreportaron la especialidad deportiva practicada (deportes continuos vs. intermitentes) y el número de sesiones de entrenamiento semanal. Resultados: Los chicos presentaron mayores niveles de CF para todas las variables estudiadas (P<0.05). Análisis adicionales según la especialidad deportiva mostraron que los deportes continuos requerían un mayor número de sesiones de entrenamiento. Los mayores niveles de fuerza muscular y resistencia cardiorrespiratoria fueron observados en los atletas practicantes de deportes continuos (P<0.05). Conclusiones: Los principales hallazgos de nuestro estudio indican que la práctica de deportes continuos conlleva una mayor dedicación y parece reportar mayores niveles de CF respecto a los deportes intermitentes. Futuras investigaciones que traten de explicar los motivos de las diferencias encontradas resultan necesarias para comprender el impacto de la práctica deportiva durante la adolescencia.Introduction: Physical fitness (PF) is a powerful marker of physical and mental health in youth. Participation in organized-sports is the most common form of leisure time physical activity, reporting many health benefits. The contribution of sport practice to PF depends on the specific characteristics of the activity. The aim of our study was to examine the association of sport characteristics with PF in healthy adolescents. Methods: A sample of 164 athletes (101 males) aged 13.9±0.3y from DADOS Study was selected. Muscular strength was measured with the handgrip and the standing long jump tests. Speed-agility was measured with the 4x10m shuttle run test. Cardiorespiratory fitness was measured with the 20m shuttle run test. Sport speciality and weekly sessions were self-reported by participants. Sport specialities were dichotomized as continuous and intermittent sports. Results: Boys showed higher levels of PF than girls for all studied variables, with no differences in the number of organized-sports weekly sessions (all P<0.05). Additional analysis according to sport speciality showed that athletes from continuous sports completed more weekly sessions compared with intermittent sports. Comparisons of sport speciality by gender revealed higher levels of muscular and cardiorespiratory fitness for boys and girls practising continuous sports (e.g. swimming, cycling) compared with intermittent sports (e.g. basketball) (all P<0.05). Conclusions: The main findings of our study indicate that continuous sports are more time demanding than intermittent ones. Moreover, athletes from continuous sports seem to be fitter than adolescents from intermittent sports. Further research is needed to clarify the reason of our results

IRAS 21391+5802: The Molecular Outflow and its Exciting Source

We present centimeter and millimeter observations of gas and dust around IRAS 21391+5802, an intermediate-mass source embedded in the core of IC 1396N. Continuum observations from 3.6 cm to 1.2 mm are used to study the embedded objects and overall distribution of the dust, while molecular line observations of CO, CS, and CH3OH are used to probe the structure and chemistry of the outflows in the region. The continuum emission at centimeter and millimeter wavelengths has been resolved into three sources separated about 15 arcsec from each other, and with one of them, BIMA 2, associated with IRAS 21391+5802. The dust emission around this source shows a very extended envelope, which accounts for most of the circumstellar mass of 5.1 Msun. This source is powering a strong molecular outflow, elongated in the E--W direction, which presents a complex structure and kinematics. While at high outflow velocities the outflow is clearly bipolar, at low outflow velocities the blueshifted and redshifted emission are highly overlapping, and the strongest emission shows a V-shaped morphology. The outflow as traced by CS and CH3OH exhibits two well differentiated and clumpy lobes, with two prominent northern blueshifted and redshifted clumps. The curved shape of the clumps and the spectral shape at these positions are consistent with shocked material. In addition, CS and CH3OH are strongly enhanced toward these positions with respect to typical quiescent material abundances in other star-forming regions.Comment: 41 pages, including 11 figures, accepted for publication in ApJ (July 1); available at http://www.am.ub.es/~robert/Papers.html#las

Isocurvature modes and Baryon Acoustic Oscillations

The measurement of Baryonic Acoustic Oscillations from galaxy surveys is well known to be a robust and powerful tool to constrain dark energy. This method relies on the knowledge of the size of the acoustic horizon at radiation drag derived from Cosmic Microwave Background Anisotropy measurements. In this paper we quantify the effect of non-standard initial conditions in the form of an isocurvature component on the determination of dark energy parameters from future BAO surveys. In particular, if there is an isocurvature component (at a level still allowed by present data) but it is ignored in the CMB analysis, the sound horizon and cosmological parameters determination is biased, and, as a consequence, future surveys may incorrectly suggest deviations from a cosmological constant. In order to recover an unbiased determination of the sound horizon and dark energy parameters, a component of isocurvature perturbations must be included in the model when analyzing CMB data. Fortunately, doing so does not increase parameter errors significantly.Comment: 23 pages, 3 figure

Gravitational stability and dynamical overheating of stellar disks of galaxies

We use the marginal stability condition for galactic disks and the stellar velocity dispersion data published by different authors to place upper limits on the disk local surface density at two radial scalelengths $R=2h$. Extrapolating these estimates, we constrain the total mass of the disks and compare these estimates to those based on the photometry and color of stellar populations. The comparison reveals that the stellar disks of most of spiral galaxies in our sample cannot be substantially overheated and are therefore unlikely to have experienced a significant merging event in their history. The same conclusion applies to some, but not all of the S0 galaxies we consider. However, a substantial part of the early type galaxies do show the stellar velocity dispersion well in excess of the gravitational stability threshold suggesting a major merger event in the past. We find dynamically overheated disks among both seemingly isolated galaxies and those forming pairs. The ratio of the marginal stability disk mass estimate to the total galaxy mass within four radial scalelengths remains within a range of 0.4---0.8. We see no evidence for a noticeable running of this ratio with either the morphological type or color index.Comment: 25 pages, 5 figures, accepted to Astronomy Letter