Progression of world records in master swimming

Master sports is increasingly popular nad arguably becoming more competitive worldwideinfo:eu-repo/semantics/publishedVersio

Editorial: Coaches' role in youth sports performance: early specialization versus long-term development

Youth sports are planned sports programs for children and adolescents with designated coaches, organized practices, and scheduled competitions. Such programs can be organized and implemented at schools (by physical education teachers instead of coaches), as well as in other sports organizations (i.e., federations, associations, local clubs). Primary aim should be to focus on providing young athletes with fundamental motor skills in tandem to their maturation stage. Indeed, these programs are aimed at mass participation rather than on developing elite athletes. The participation in such programs during childhood and adolescence showed to have major benefits in children’s and adolescent’s physical, psychological, and social development. On the other hand, youth sports programs can also serve as a link to talent identification and development programs aiming to identify young athletes with potential for success in adult/elite sport. As they aremass orientated,many youth athletes can be observed which will increase the likelihood of talent identification. Afterwards, these athletes can be guided to high-performance programs aiming to achieve eventually an elite level.info:eu-repo/semantics/publishedVersio

Hipogonadismo de inicio tardío: revisión de conceptos y pautas diagnósticas

ResumenEl hipogonadismo de inicio tardío es un síndrome clínico y bioquímico cada vez más frecuente entre la población masculina en la edad adulta, sin embargo pocas veces es diagnosticado y por lo tanto cursa sin tratamiento entre la mayoría de los varones afectados. La asociación entre deficiencia de testosterona relacionada con la edad y el diagnóstico de hipogonadismo de inicio tardío continúa siendo un tema controversial, y su asociación con síntomas como pérdida de volumen y fuerza muscular, pérdida de la libido y la función eréctil, así como cambios en el estado afectivo e intelectual del paciente resulta insidiosa ya que en ocasiones las sintomatología es atribuida al proceso «normal» de envejecimiento, o a otras comorbilidades del paciente. El diagnóstico de hipogonadismo de inicio tardío se basa en la coexistencia de bajos niveles séricos de testosterona total o libre y síntomas sugestivos de hipogonadismo. Si bien se han desarrollado cuestionarios de cribado dirigidos a pacientes con sospecha clínica, estos cuestionarios poseen sensibilidad y especificidad limitadas para el diagnóstico de hipogonadismo de inicio tardío. El diagnóstico preciso y oportuno es de crucial importancia ya que permite restablecer los niveles de testosterona y la mejoría clínica significativa mediante la terapia de remplazo hormonal.AbstractLate-onset hypogonadism is a clinical and biochemical syndrome that is increasingly more frequent in the adult male population. However, it is rarely diagnosed and therefore goes untreated in the majority of affected men. The association between age-related testosterone deficiency and late-onset hypogonadism continues to be a subject of debate and its relation to symptoms such as loss of muscle strength and volume, loss of libido, erectile dysfunction, and changes in affective and emotional statuses of the patient are insidious, given that the symptomatology is often attributed to the “normal” aging process or other comorbidities of the patient. The diagnosis of late-onset hypogonadism is based on the coexistence of low total or free testosterone serum levels and symptoms suggestive of hypogonadism. Even though screening questionnaires directed at patients with clinical suspicion of the disease have been developed for late-onset hypogonadism, their diagnostic sensitivity and specificity is limited. Accurate and opportune diagnosis is vitally important because it enables testosterone levels to be reestablished and significant clinical improvement to be made through androgen replacement therapy

Stability analysis and prediction of pacing in elite 1500 m freestyle male swimmers

This study aimed to analyse the stability of elite male long-distance swimmers (1500 m), and to identify the main predictors related to the pace. The performance of 16 elite male swimmers (22.59 ± 2.10 years-old) participating in the 1500 m event at the 2016 (London) and 2018 (Glasgow) LEN European Aquatic Championships were analysed. The lap performance, clean swim performance, turn performance, and a set of stroke mechanics variables were assessed. The lap performance presented a significant and moderate variation with all laps included (p < 0.001) and deleting the first and last lap (p = 0.002). Swimmers were significantly faster in the first half in comparison of the second. The total turn also presented a significant and moderate variation. The hierarchical linear modelling retained the time (estimate = 0.0019, p = 0.007), stroke frequency (estimate = -27.49, p < 0.001) and stroke length (estimate = -6.55, p < 0.001) as the main predictors of the clean swim performance. By contrast to the analysis based on the lap performance, clean swim performance presented a non-significant variation. Coaches should be aware that stroke length maintenance could negatively affect the clean swim performance, whereas a small increase of stroke frequency may present a meaningful enhancement of the total race time.This project was supported by the National Funds through FCT - Portuguese Foundation for Science and Technology [UIDB/DTP/04045/2020]info:eu-repo/semantics/publishedVersio

Statistical disclosure control in tabular data

Data disseminated by National Statistical Agencies (NSAs) can be classified as either microdata or tabular data. Tabular data is obtained from microdata by crossing one or more categorical variables. Although cell tables provide aggregated information, they also need to be protected. This chapter is a short introduction to tabular data protection. It contains three main sections. The first one shows the different types of tables that can be obtained, and how they are modeled. The second describes the practical rules for detection of sensitive cells that are used by NSAs. Finally, an overview of protection methods is provided, with a particular focus on two of them: “cell suppression problem” and “controlled tabular adjustment”.Postprint (published version

A burst with double radio spectrum observed up to 212 GHz

We study a solar flare that occurred on September 10, 2002, in active region NOAA 10105 starting around 14:52 UT and lasting approximately 5 minutes in the radio range. The event was classified as M2.9 in X-rays and 1N in H\alpha. Solar Submillimeter Telescope observations, in addition to microwave data give us a good spectral coverage between 1.415 and 212 GHz. We combine these data with ultraviolet images, hard and soft X-rays observations and full-disk magnetograms. Images obtained from Ramaty High Energy Solar Spectroscopic Imaging data are used to identify the locations of X-ray sources at different energies and to determine the X-ray spectrum, while ultra violet images allow us to characterize the coronal flaring region. The magnetic field evolution of the active region is analyzed using Michelson Doppler Imager magnetograms. The burst is detected at all available radio-frequencies. X-ray images (between 12 keV and 300 keV) reveal two compact sources and 212 GHz data, used to estimate the radio source position, show a single compact source displaced by 25" from one of the hard X-ray footpoints. We model the radio spectra using two homogeneous sources, and combine this analysis with that of hard X-rays to understand the dynamics of the particles. Relativistic particles, observed at radio wavelengths above 50 GHz, have an electron index evolving with the typical soft-hard-soft behaviour.Comment: Submitted to Solar Physics, 20 pages, 8 fugure

Preparation and Characterization of Homogeneous YBCO Single Crystals with Doping Level near the SC-AFM Boundary

High-purity and homogeneous YBa2Cu3Oy single crystals with carrier doping level near the AFM-SC boundary have been obtained in the oxygen content range between y = 6.340 and 6.370. The crystals are ortho-II phase at room temperature and undergo the orthorhombic to tetragonal transition at about 140_Degree_C. They show sharp superconducting transitions, with Tc between 4 and 20 K. Tc changes by 0.8 K when the oxygen content y is changed by 0.001, and is also sensitive to annealing conditions near room temperature, due to the dependence of doping on oxygen ordering correlation lengths. Crystals with oxygen content y lower than 6.345 are non-superconducting.Comment: 6 page

Monte Carlo study of the critical temperature for the planar rotator model with nonmagnetic impurities

We performed Monte Carlo simulations to calculate the Berezinskii-Kosterlitz-Thouless (BKT) temperature $T_{BKT}$ for the two-dimensional planar rotator model in the presence of nonmagnetic impurity concentration $(\rho)$. As expected, our calculation shows that the BKT temperature decreases as the spin vacancies increase. There is a critical dilution $\rho_c \approx 0.3$ at which $T_{BKT} =0$. The effective interaction between a vortex-antivortex pair and a static nonmagnetic impurity is studied analytically. A simple phenomenological argument based on the pair-impurity interaction is proposed to justify the simulations.Comment: 5 pages, 5 figures, Revetex fil

Electromagnetic Response of Layered Superconductors with Broken Lattice Inversion Symmetry

We investigate the macroscopic effects of charge density waves (CDW) and superconductivity in layered superconducting systems with broken lattice inversion symmetry (allowing for piezoelectricity) such as two dimensional (2D) transition metal dichalcogenides (TMD). We work with the low temperature time dependent Ginzburg-Landau theory and study the coupling of lattice distortions and low energy CDW collective modes to the superconducting order parameter in the presence of electromagnetic fields. We show that superconductivity and piezoelectricity can coexist in these singular metals. Furthermore, our study indicates the nature of the quantum phase transition between a commensurate CDW phase and the stripe phase that has been observed as a function of applied pressure.Comment: 9 pages, 1 figure. Final version. Accepted in Phys.Rev.

Quantum effective potential for U(1) fields on S^2_L X S^2_L

We compute the one-loop effective potential for noncommutative U(1) gauge fields on S^2_L X S^2_L. We show the existence of a novel phase transition in the model from the 4-dimensional space S^2_L X S^2_L to a matrix phase where the spheres collapse under the effect of quantum fluctuations. It is also shown that the transition to the matrix phase occurs at infinite value of the gauge coupling constant when the mass of the two normal components of the gauge field on S^2_L X S^2_L is sent to infinity.Comment: 13 pages. one figur