[Functional evaluation of the management of massive rotator cuff ruptures with the use of the subacromial balloo]. / Evaluación funcional del manejo de rupturas masivas del manguito de los rotadores con el uso del balón subacromial.

INTRODUCTION: Rotator cuff (MR) ruptures occur in more than 50% of patients over the age of 60, and can cause changes in normal shoulder biomechanics that can trigger rotator cuff tear arthropathy. There is currently no consensus on treatment for massive rotator cuff tears. OBJECTIVE: To evaluate the clinical and radiographic outcomes of subacromial balloon placement in these lesions. MATERIAL AND METHODS: Analytical, longitudinal and retrospective study of 10 consecutive patients treated with the use of the subacromial balloon. Constant (CS) and ASES scales were used preoperatively and at 6, 12 months of post-surgical follow-up. Radiographic results were assessed using the Acromio-humeral Interval (AHI) on a true AP shoulder X-ray. RESULTS: The average improvement in CS was 41.7 ± 8.93 at 12 months of follow-up, the ASES scale showed an average improvement of 64.6 ± 4.9 at 12 months of follow-up. The presurgical AHI was 6.1 ± 1.10 and the mean at 12 months of follow-up was 7.1 ± 0.9. Clinical and radiographic improvement was observed at all scales, however no statistically significant results were found. CONCLUSION: The subacromial balloon prevents the ascent of the humeral head in the first 12 months of placement; we assume that it could restore normal glenohumeral kinematics by improving mobility and decreasing pain.

INTRODUCCIÓN: Las rupturas del manguito de los rotadores (MR) se presentan en más de 50% de los pacientes mayores de 60 años y pueden causar cambios en la biomecánica normal del hombro que pueden desencadenar una artropatía por desgarro del MR. Actualmente, no existe un consenso sobre el tratamiento para el desgarro masivo del MR. OBJETIVO: Evaluar los resultados clínicos y radiográficos de la colocación del balón subacromial en estas lesiones. MATERIAL Y MÉTODOS: Estudio analítico, longitudinal y retrospectivo de 10 pacientes consecutivos tratados con el uso del balón subacromial. Se utilizaron escalas de Constant (CS) y ASES prequirúrgicas, a los seis y 12 meses de seguimiento postquirúrgico. Los resultados radiográficos fueron valorados por medio del intervalo acromio-humeral (IAH) en una radiografía anteroposterior (AP) verdadera de hombro. RESULTADOS: La mejoría promedio en la CS fue de 41.7 ± 8.93 a los 12 meses de seguimiento, la escala de ASES mostró una mejoría promedio de 64.6 ± 4.9 a los 12 meses de seguimiento. El IAH prequirúrgico fue de 6.1 ± 1.10 y la media a los 12 meses de seguimiento fue de 7.1 ± 0.9. Se observó una mejoría clínica y radiográfica en todas las escalas; sin embargo, no se encontraron resultados estadísticamente significativos. CONCLUSIÓN: El balón subacromial previene el ascenso de la cabeza humeral en los primeros 12 meses de colocado; suponemos que podría restaurar la cinemática glenohumeral normal mejorando movilidad y disminuyendo dolor.

The cosmic ray shadow of the Moon observed with the ANTARES neutrino telescope.

One of the main objectives of the ANTARES telescope is the search for point-like neutrino sources. Both the pointing accuracy and the angular resolution of the detector are important in this context and a reliable way to evaluate this performance is needed. In order to measure the pointing accuracy of the detector, one possibility is to study the shadow of the Moon, i.e. the deficit of the atmospheric muon flux from the direction of the Moon induced by the absorption of cosmic rays. Analysing the data taken between 2007 and 2016, the Moon shadow is observed with 3.5 σ statistical significance. The detector angular resolution for downward-going muons is 0 . 73 ∘ ± 0 . 14 ∘ . The resulting pointing performance is consistent with the expectations. An independent check of the telescope pointing accuracy is realised with the data collected by a shower array detector onboard of a ship temporarily moving around the ANTARES location.

Automatic Paroxysmal Atrial Fibrillation Based on not Fibrillating ECGs.

OBJECTIVES: The objective of the paper is to describe an automatic algorithm for Paroxysmal Atrial Fibrillation (PAF) Detection, based on parameters extracted from ECG traces with no atrial fibrillation episode. The modular automatic classification algorithm for PAF diagnosis is developed and evaluated with different parameter configurations. METHODS: The database used in this study was provided by Physiobank for The Computers in Cardiology Challenge 2001. Each ECG file in this database was translated into a 48 parameter vector. The modular classification algorithm used for PAF diagnosis was based on the nearest K-neighbours. Several configuration options were evaluated to optimize the classification performance. RESULTS: Different configurations of the proposed modular classification algorithm were tested. The uni-parametric approach achieved a top classification rate value of 76%. A multi-parametric approach was configured using the 5 parameters with highest discrimination power, and a top classification rate of 80% was achieved; different functions to typify the parameters were tested. Finally, two automatic parametric scanning strategies, Forward and Backward methods, were adopted. The results obtained with these approaches achieved a top classification rate of 92%. CONCLUSIONS: A modular classification algorithm based on the nearest K-neighbours was designed. The classification performance of the algorithm was evaluated using different parameter configurations, typification functions and number of K-neighbors. The automatic parametric scanning techniques achieved much better results than previously tested configurations.

Multiobjective evolutionary optimization of the size, shape, and position parameters of radial basis function networks for function approximation.

This paper presents a multiobjective evolutionary algorithm to optimize radial basis function neural networks (RBFNNs) in order to approach target functions from a set of input-output pairs. The procedure allows the application of heuristics to improve the solution of the problem at hand by including some new genetic operators in the evolutionary process. These new operators are based on two well-known matrix transformations: singular value decomposition (SVD) and orthogonal least squares (OLS), which have been used to define new mutation operators that produce local or global modifications in the radial basis functions (RBFs) of the networks (the individuals in the population in the evolutionary procedure). After analyzing the efficiency of the different operators, we have shown that the global mutation operators yield an improved procedure to adjust the parameters of the RBFNNs.

Short-term prediction of chaotic time series by using RBF network with regression weights.

We propose a framework for constructing and training a radial basis function (RBF) neural network. The structure of the gaussian functions is modified using a pseudo-gaussian function (PG) in which two scaling parameters sigma are introduced, which eliminates the symmetry restriction and provides the neurons in the hidden layer with greater flexibility with respect to function approximation. We propose a modified PG-BF (pseudo-gaussian basis function) network in which the regression weights are used to replace the constant weights in the output layer. For this purpose, a sequential learning algorithm is presented to adapt the structure of the network, in which it is possible to create a new hidden unit and also to detect and remove inactive units. A salient feature of the network systems is that the method used for calculating the overall output is the weighted average of the output associated with each receptive field. The superior performance of the proposed PG-BF system over the standard RBF are illustrated using the problem of short-term prediction of chaotic time series.

Vibration-evoked sensory nerve action potentials derived from Pacinian corpuscles.

To evaluate sensory response to natural stimuli, we developed a method to record sensory nerve action potentials evoked by high-frequency vibratory stimulation. Trains of 250 Hz sinusoidal indentations with a duration of 100 msec were applied to the finger tip at a rate of 3 Hz. The responses were obtained with surface electrodes placed over the median and ulnar nerves at the wrist. Averaged wave forms consisted of two components: an initial diphasic or triphasic potential and the following low amplitude trains of discharges phase-locked to vibratory stimuli. Anesthesia of the skin at the stimulation site or tourniquet-induced ischemia of the limb eventually diminished both components. Neither of them therefore represented artifacts from electrode movement or electromagnetic field intrinsic to the stimulator. Various kinds of mechanoreceptors may contribute to the first component. Pacinian corpuscles probably give rise to the second component as the only skin receptors that can respond to high-frequency vibratory stimuli of 250 Hz. This method helps examine neural coding of the receptor and the peripheral nerve fiber mediating vibration sense.

Effect of sodium deprivation on contraction and charge movement in frog skeletal muscle fibres.

Measurements of isometric tension were performed in single twitch skeletal muscle fibres and the effect of extracellular Na+ removal on contraction was investigated. Na+ withdrawal brought about an increase in the amplitude of K+ contractures and their time course became faster. The potentiation of K+ contractures depended strongly on extracellular Ca2+ and developed slowly following an exponential time course with a time constant of approximately 8 min. Removal of extracellular Na+ greatly increased the amplitude of caffeine contractures and lowered its threshold: caffeine (0.5 mM) had no effect on resting tension in Ringer's but produced contractures in Na(+)-free solutions. Intramembrane charge movement (charge 1) was monitored in contracting voltage-clamped segments of frog skeletal muscle fibres using the triple-Vaseline-gap technique. Movement of charge 1 did not depend on the presence of extracellular Na+. However, the mechanical threshold decreased by approximately 10 mV at several pulse durations and the charge which produced just detectable contractions decreased by approximately 5 nC microF-1 in the absence of extracellular Na+. Intracellular heparin (40 mg ml-1) increased the mechanical threshold by approximately 20 mV without affecting the movement of charge 1. The effect of Na(+)-free solutions on the mechanical threshold was additive to that of heparin. It is concluded that the effects of Na(+)-withdrawal on contraction take place at a location beyond the voltage sensor of excitation-contraction coupling.