Estudi comparatiu sobre la tècnica del copejament clàssic i pla en hoquei sobre herba

El llançament estacionari a porteria és un element tècnic i tàctic molt important en l’entrenament de l’hoquei sobre herba. Existeix una variant del copejament tradicional, anomenada “copejament pla o baix”, en la qual l’estic defineix una trajectòria més horitzontal durant el descens. Aquesta tècnica gaudeix d’acceptació en l’àmbit pràctic i és entrenada com a fonament tècnic d’alta eficàcia (direcció més precisa i major velocitat) en situacions de bola aturada, com en el cas del penal córner. Ara com ara, els estudis realitzats sobre el copejament pla són escassos i només estableixen algunes diferències respecte del copejament tradicional, atenent a la trajectòria i a les posicions angulars d’alguns segments corporals i de l’estic. El propòsit del nostre treball és analitzar comparativament totes dues tècniques, per establir quines són les principals diferències des d’un punt de vista biomecànic i atenent a variables cinemàtiques

Remediación agua contaminada por mercurio y portlandita en Flix

Hace unos años se decidió descontaminar el embalse de Flix, afectado por vertidos de residuos por un empresa química durante todo el siglo pasado. •Los residuos formaron 4 lóbulos de sedimentos en el río, con elevadas concentraciones de Mercurio, compuestos orgánicos volátiles (COV´s), residuos de producción de acetileno (Ca(OH)2) y pesticidas organoclorados. •Se ha realizado un modelo 0D de transporte reactivo de la concentración en el agua conforme se excavan los sedimentos transitorio y explícito en excel, calibrado hasta Septiembre 2014 con datos semanales de la empresa extractora FCC. •El modelo concluía dos graves problemas al terminar la excavación: Elevada concentración de Hg y pH (12.4), equilibrado con portlandita •Desde Marzo de 2015 se observó un acusado descenso de pH y Hg. Nuestro objetivo ha sido encontrar la causa de estos descensos, para ello se han realizado simulaciones, muestreos y experimentos de laboratorio. La precipitación CaCO3 debida a la difusión de CO2 atmosférico explica una parte de la disminución de pH, pero resulta insuficiente aun considerando la oxidación de materia orgánica. •El Hg se adsorbido en CaCO3 es alrededor de un 30%, otro 60% parece haberse volatilizado. •La electrolisis en laboratorio reproduce un descenso del Hg de 80% en 3 días. Sólo un 10% de Hg ha sido recuperado en el cátodo. • Se cree que el Hg2+ se reduce a Hg0 y volatiliza. •El pH descendió hasta 3.8, se cree que debido a hidrólisis del agua. •Se esta trabajando en comprobar el Hg0 volatilizado en próximos experimentos.Postprint (published version

Feasibility of a brief mindfulness-based program for burnout in pain healthcare professionals

Introduction: Stress inherent to health care, which is characterized by work overload and shortage of specialized staff, is associated with decreased quality of life and suboptimal patient care. Mindfulness-based programs have proved to be effective in reducing stress in healthcare providers. This study aims to assess the feasibility of an 8-week mindfulness program to reduce the burnout levels of the staff of a pain clinic in a tertiary public hospital. Materials and methods: A longitudinal study with a within subject pre/post-intervention design, consisting of daily face-to-face 10-min sessions and the creation of a virtual group using a social media platform. Variables measured: burnout, mindfulness, empathy, self-compassion, and demographic characteristics. Results: Program feasibility (i.e., reach, adherence, acceptability, and preliminary effectiveness) was evaluated in 10 participants (6 physicians, 2 nurse practitioners, 1 nursing assistant, and 1 administrative). The results revealed a high reach (i.e., participation rate of 90%), excellent adherence to the program (daily practice 95% of times), and very good acceptability of the group format and satisfaction with most treatment components. Regarding potential effectiveness, we report the results of the Wilcoxon signed-rank tests and its associated effect size (r). We observed improvements in mindfulness and all its subscales (−2.077 ≤ Z ≤ −2.703, 0.69 ≤ r ≤ 0.90, all p < 0.05) except for non-reactivity and all subcomponents of self-compassion (−2.501 ≤ Z ≤ −2.611, 0.83 ≤ r ≤ 0.87, all p < 0.05) but not on its global self-compassion score. Empathy and burnout did not change. In an exploratory manner, however, we found significant reductions in the burnout component of emotional exhaustion, but only in physicians (Z = −2.201, p = 0.028, r = 0.73). Discussion: We believe that the 8-week mindfulness-based program described in the present investigation might be a feasible and potentially effective method that can be easily implemented to reduce burnout and promote mindfulness in specialized pain clinics

Estudio comparativo sobre la técnica del golpeo clásico y plano en hockey hierba

El lanzamiento estacionario a portería es un elemento técnico y táctico muy importante en el entrenamiento del hockey hierba. Existe una variante del golpeo tradicional, denominada “golpeo plano o bajo”, en la cual el stick define una trayectoria más horizontal durante su descenso. Esta técnica goza de aceptación en el ámbito práctico y es entrenada como fundamento técnico de alta eficacia (dirección más precisa y mayor velocidad) en situaciones de bola parada como en el caso del penalti corner. Hasta ahora los estudios realizados sobre el golpeo plano son escasos y sólo establecen algunas diferencias con respecto al golpeo tradicional, atendiendo a la trayectoria y posiciones angulares de algunos segmentos corporales y del stick. El propósito del presente trabajo es analizar comparativamente ambas técnicas, para establecer cuales son las principales diferencias desde un punto de vista biomecánico y atendiendo a variables cinemáticas

Performance of a behavioral model with long-term memory effects

This paper presents a new behavioral model for power amplifiers that accomplishes the capture of nonlinear low-frequency memory effects with reduced complexity and superior precision. It has been extensively evaluated with a commercial amplifier using wideband code-division multiple-access (WCDMA)-like modulated data with symbol rates in the range of 2 ksym/s to 1 Msym/s, and it is shown that the first dynamic reduction of the proposed model is successfully compared with other highly efficient methods in terms of complexity and generalization capacity.CICYT TEC2011-23559Junta de Andalucía P11-TIC-786

Comparative Analysis of Greedy Pursuits for the Order Reduction of Wideband Digital Predistorters

This paper provides a review of greedy pursuits for optimizing Volterra-based behavioral models structure and estimating its parameters. An experimental comparison of the digital predistortion (DPD) linearization performance achieved by these approaches for model-order reduction, such as compressive sampling matching pursuit (CoSaMP), subspace pursuit (SP), orthogonal matching pursuit (OMP), and the novel doubly OMP (DOMP), is presented. A benchmark of the techniques in the DPD of a commercial class AB power amplifier (PA) and a class J PA operating over a 15-MHz Long-Term Evolution (LTE) signal is presented, giving a clear overview of their pruning characteristics in terms of linearization indicators and regressor selection capabilities. In addition, the benchmark is run in a cross-validation scheme by identifying the DPD with a 30-MHz 5G-new radio (NR) signal and validating with the same signal and a 20-MHz multicarrier wideband code division multiple access (WCDMA) signal. The DOMP is shown to be a promising technique since it achieves an enhanced model-order reduction for a similar linearization performance and precision

Volterra Behavioral Model for Wideband RF Amplifiers

This paper proposes a behavioral modeling approach for the description of nonlinearities in wideband wireless communication circuits with memory. The model is formally derived exploiting the dependence on frequency of the amplifier nonlinear transfer functions and reduce the number of parameters in a general Volterra-based behavioral model. To validate the proposed approach, a commercial amplifier at 915 MHz, exhibiting nonlinear memory effects, has been widely characterized using different stimuli, including two tones, quadrature phase-shift keying wideband code division multiple access, and 16-quadrature amplitude modulation signals with rectangular and root-raised cosine conforming pulses. The theoretical results have been compared with experimental data demonstrating that the model performance is comparable to the well-established memory polynomial model. Calculated and measured baseband waveforms, signal constellation, spectral regrowth and adjacent channel power ratio are tightly coincident in all cases, emphasizing the relevance of the proposed modelCICYT TEC2004-06451-C05-0

Amplifier Nonlinear Modeling with RF Pulses

This paper proposes a Volterra kernel identification procedure for wireless amplifiers with nonlinear memory. The technique is based on a reduced-order Volterra model for wideband amplifiers that is favorably compared with widely used memory polynomial model in terms of normalized mean square error. The identification method takes advantage of the particular model structure and is thoroughly derived with a proper selection of pulse-like waveforms of known amplitude as probing signals with special emphasis on the extraction of the fifth-order kernel. The main advantage of the method is that it allows exploring the dynamic range of the amplifier without rising the temperature in the device or altering the biasing point. For validation purposes, a commercial amplifier has been characterized and the extracted kernels have been used to predict the response under wideband code-division multiple-access-like signals. In addition to the simplicity of the deterministic approach used in this extraction procedure, the agreement of the predicted responses with measurements was highly satisfactory in all cases and permitted the capture of phenomena that are due to nonlinear memory effects.CICYT TEC2004-06451-C05-03Junta de Andalucía Grant P07-TIC-0264