Bisections of centrally symmetric planar convex bodies minimizing the maximum relative diameter

In this paper we study the bisections of a centrally symmetric planar convex body which minimize the maximum relative diameter functional. We give necessary and sufficient conditions for being a minimizing bisection, as well as analyzing the behavior of the so-called standard bisection.Ministerio de Economía e Innovación MTM2013-48371-C2-1-PJunta de Andalucía FQM-32

Subdivisions of rotationally symmetric planar convex bodies minimizing the maximum relative diameter

In this work we study subdivisions of k-rotationally symmetric planar convex bodies that minimize the maximum relative diameter functional. For some particular subdivisions called k-partitions, consisting of k curves meeting in an interior vertex, we prove that the so-called standard k-partition (given by k equiangular inradius segments) is minimizing for any k 2 N, k > 3. For general subdivisions, we show that the previous result only holds for k 6 6. We also study the optimal set for this problem, obtaining that for each k 2 N, k > 3, it consists of the intersection of the unit circle with the corresponding regular k-gon of certain area. Finally, we also discuss the problem for planar convex sets and large values of k, and conjecture the optimal k-subdivision in this case.Ministerio de Educación y Ciencia MTM2010-21206-C02-01Ministerio de Economía e Innovación MTM2013-48371-C2-1-PJunta de Andalucía FQM-325Junta de Andalucía P09-FQM-508

Gender and age differences in self-concept in Chilean adolescent students

Investigaciones previas han puesto de manifiesto la importancia del estudio del autoconcepto durante la adolescencia. El objetivo de este estudio consistió en analizar las diferencias de género y edad en las distintas dimensiones del autoconcepto en una muestra de 1414 estudiantes chilenos de entre 13 y 18 años. El autoconcepto fue evaluado mediante la versión breve del SDQII. Los resultados evidenciaron diferencias de género para las dimensiones Autoconcepto Verbal, Apariencia Física, Sinceridad/Veracidad y Autoestima en favor de las jóvenes, así como diferencias en el Autoconcepto Matemático, Habilidades Físicas, Estabilidad Emocional y Relación con los Padres en favor de los varones. También se observó una tendencia en los alumnos de mayor edad a puntuar más alto en Autoconcepto Académico General, Habilidades Físicas, Apariencia Física, Relaciones con el Sexo Opuesto y Autoestima, que sus iguales de menor edad. Este mismo patrón, pero a la inversa, se obtuvo para las dimensiones de Autoconcepto Matemático, Verbal y Estabilidad Emocional. Los resultados no replicaron la tendencia de los varones, reportada en estudios previos, a valorar más positivamente su físico y a poseer una autoestima más elevada que las mujeres, así como a percibir más negativamente sus relaciones paterno-filiales.Previous researches have highlighted the importance of the study of self-concept in adolescence. The aim of this study was to analyse gender and age differences in several dimensions of the self-concept. The sample included 1414 Chilean students between 13 and 18 years old. The self-concept was assessed using the SDQII-Short form. Results revealed that girls scored significantly higher in Verbal, Physical Appearance, Honesty-Trustworthiness and Self-esteem self-concepts, whereas boys got higher scores in Maths, Physical Ability, Emotional Stability and Parents Relations self-concepts. It was also observed that older students scored higher in general Academic Self-concept, Physical Ability, Physical Appearance, Opposite Sex Relations and Self-esteem than their younger peers. This same pattern, but the other way round, was obtained for Maths, Verbal and Emotional Stability dimensions. The outcomes did not argue the tendency for men, reported in previous studies, to value more positively their physical appearance and to own higher self-esteem than women, as well as perceive more negatively their parent-child relationships

Tetrathiafulvalene-Calix[4]Pyrrole in the Chloride Anion Controled Molecular Recognition of 2,5,7-trinitro-9-dicyanomethylenefluorene-C60

Date du colloque : 05/2008International audienc

Gestor intel·ligent d'assignació de recursos

Aquest projecte és una eina per a la gestió avançada del Comitè Tècnic d'Àrbitres de Futbol Sala de Catalunya. Creant una base de dades forta i robusta com la que ens proporciona la tecnologia ORACLE, i agafant APEX com a gestor de continguts de la base de dades, hem creat una aplicació per realitzar l'assignació d'arbitratges i altres recursos d'una manera intel·ligent i equitativa.Este proyecto es una herramienta de gestión avanzada para el Comité Técnico de Árbitros de Fútbol Sala de Catalunya. Creando una base de datos fuerte y robusta como la que nos proporciona la tecnología ORACLE, y tomando APEX como gestor de contenidos de la base de datos, hemos elaborado una aplicación para realizar una asignación de arbitrajes y otros recursos de una manera inteligente y equitativa.This project is a tool for the advanced management of the Catalonia Futsal Referee Technical Committee. Designing a strong database with ORACLE technology, and having APEX as the content manager of the database, we have created a fair and intelligent application for the refereeing assignment and other resources

ECG-based monitoring of blood potassium concentration: Periodic versus principal component as lead transformation for biomarker robustness

Objective: The aim of this study is to compare the performance of two electrocardiogram (ECG) lead-space reduction (LSR) techniques in generating a transformed ECG lead from which T-wave morphology markers can be reliably derived to non-invasively monitor blood potassium concentration ([K+]) in end-stage renal disease (ESRD) patients undergoing hemodialysis (HD). These LSR techniques are: (1) principal component analysis (PCA), learned on the T wave, and (2) periodic component analysis (πCA), either learned on the whole QRST complex (πCB) or on the T wave (πCT). We hypothesized πCA is less sensitive to non-periodic disturbances, like noise and body position changes (BPC), than PCA, thus leading to more reliable T wave morphology markers. Methods: We compared the ability of T wave morphology markers obtained from PCA, πCB and πCT in tracking [K+] in an ESRD-HD dataset, including 29 patients, during and after HD (evaluated by correlation and residual fitting error analysis). We also studied their robustness to BPC using an annotated database, including 20 healthy individuals, as well as to different levels of noise using a simulation set-up (assessed by means of Mann–Whitney U test and relative error, respectively). Results: The performance of both πCB and πCT-based markers in following [K+]-variations during HD was comparable, and superior to that from PCA-based markers. Moreover, πCT-based markers showed superior robustness against BPC and noise. Conclusion: Both πCB and πCT outperform PCA in terms of monitoring [K+] in ESRD-HD patients, as well as of robustness against BPC and low SNR, with πCT showing the highest stability for continuous post-HD monitoring. Significance: The usage of πCA (i) increases the accuracy in monitoring dynamic [K+] variations in ESRD-HD patients and (ii) reduces the sensitivity to BPC and noise in deriving T wave morphology markers. © 2021 The Author(s

Guest-responsive polaritons in a porous framework: chromophoric sponges in optical QED cavities

Introducing porous material into optical cavities is a critical step toward the utilization of quantum-electrodynamical (QED) effects for advanced technologies, e.g. in the context of sensing. We demonstrate that crystalline, porous metal–organic frameworks (MOFs) are well suited for the fabrication of optical cavities. In going beyond functionalities offered by other materials, they allow for the reversible loading and release of guest species into and out of optical resonators. For an all-metal mirror-based Fabry–Perot cavity we yield strong coupling (∼21% Rabi splitting). This value is remarkably large, considering that the high porosity of the framework reduces the density of optically active moieties relative to the corresponding bulk structure by ∼60%. Such a strong response of a porous chromophoric scaffold could only be realized by employing silicon-phthalocyanine (SiPc) dyes designed to undergo strong J-aggregation when assembled into a MOF. Integration of the SiPc MOF as active component into the optical microcavity was realized by employing a layer-by-layer method. The new functionality opens up the possibility to reversibly and continuously tune QED devices and to use them as optical sensors

Correction: Guest-responsive polaritons in a porous framework: chromophoric sponges in optical QED cavities

Correction for ‘Guest-responsive polaritons in a porous framework: chromophoric sponges in optical QED cavities’ by Ritesh Haldar et al., Chem. Sci., 2020, DOI: 10.1039/d0sc02436

Monitoring blood potassium concentration in hemodialysis patients by quantifying T-wave morphology dynamics.

We investigated the ability of time-warping-based ECG-derived markers of T-wave morphology changes in time ([Formula: see text]) and amplitude ([Formula: see text]), as well as their non-linear components ([Formula: see text] and [Formula: see text]), and the heart rate corrected counterpart ([Formula: see text]), to monitor potassium concentration ([Formula: see text]) changes ([Formula: see text]) in end-stage renal disease (ESRD) patients undergoing hemodialysis (HD). We compared the performance of the proposed time-warping markers, together with other previously proposed [Formula: see text] markers, such as T-wave width ([Formula: see text]) and T-wave slope-to-amplitude ratio ([Formula: see text]), when computed from standard ECG leads as well as from principal component analysis (PCA)-based leads. 48-hour ECG recordings and a set of hourly-collected blood samples from 29 ESRD-HD patients were acquired. Values of [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] were calculated by comparing the morphology of the mean warped T-waves (MWTWs) derived at each hour along the HD with that from a reference MWTW, measured at the end of the HD. From the same MWTWs [Formula: see text] and [Formula: see text] were also extracted. Similarly, [Formula: see text] was calculated as the difference between the [Formula: see text] values at each hour and the [Formula: see text] reference level at the end of the HD session. We found that [Formula: see text] and [Formula: see text] showed higher correlation coefficients with [Formula: see text] than [Formula: see text]-Spearman's ([Formula: see text]) and Pearson's (r)-and [Formula: see text]-Spearman's ([Formula: see text])-in both SL and PCA approaches being the intra-patient median [Formula: see text] and [Formula: see text] in SL and [Formula: see text] and [Formula: see text] in PCA respectively. Our findings would point at [Formula: see text] and [Formula: see text] as the most suitable surrogate of [Formula: see text], suggesting that they could be potentially useful for non-invasive monitoring of ESRD-HD patients in hospital, as well as in ambulatory settings. Therefore, the tracking of T-wave morphology variations by means of time-warping analysis could improve continuous and remote [Formula: see text] monitoring of ESRD-HD patients and flagging risk of [Formula: see text]-related cardiovascular events