Effect of joint mobilization on the H Reflex amplitude in people with spasticity

Objective: To determine the effect of ankle joint mobilization on the H reflex amplitude of thesoleus muscle in people with spasticity. Materials and methods: A quasi-experimental study withcrossover design and simple masking was conducted in 24 randomized subjects to initiate thecontrol or experimental group. Traction and rhythmic oscillation were applied for five minutesto the ankle joint. H wave amplitude changes of Hoffmann reflex (electrical equivalent of themonosynaptic spinal reflex) was assessed, stimulating the tibial nerve at the level of the poplitealfossa and recording in the soleus muscle. In each subject 12 measurements were taken: basalrate, during and after mobilization. Changes in H reflex amplitude were calculated in relationto basal measurement. For each measurement a hypothesis test was performed (Student t test).Results: In groups of patients with brain injury and incomplete spinal cord injury, a significantdifference was found between measurements of both studies, concerning variation in H reflexamplitude during the application of joint mobilization techniques, with a decrease in the experimentalgroup and an increase in the control group. In contrast, no significant differences werefound after mobilization therapy. Patients with complete spinal cord injury showed no significantdifferences in any measurements. Conclusion: We demonstrate the effectiveness of jointmobilization in the decrease of H reflex amplitude in patients with brain injury or incompletespinal cord injury during the mobilization maneuver, but no residual effect after completion ofthe trial. This research showed no evidence regarding excitability reduction in complete spinalcord injury. We suggest that therapeutic interventions to decrease muscle tone based on the jointmobilization should be reconsidered.

Ingeniería Térmica (II).

En el presente libro se desarrollan los siguientes temas: principios básicos hidrodinámicos, flujo viscoso incomprensible, propiedades termodinámicas del agua, ciclos de máquinas térmicas, aire acondicionado (1), aire acondicionado (2), refrigeración (1), refrigeración (2), criogenia, y combustión.

Cuadernos de Física : V Física Térmica. VI Teoría Electromagnética.

Este cuaderno, engloba dos tomos; el primero de ellos se corresponde con el quinto de la serie y desarrolla el tema de la Física Térmica a lo largo de siete lecciones: Introducción a la termodinámica, Propiedades térmicas de la materia, Ecuaciones de estado, Primer y segundo principio de la termodinámica, Transiciones de fase y fenómenos de transferencia de calor. El segundo tomo se corresponde con el sexto de la serie y desarrolla el tema de la Teoría Electromagnética a lo largo de otras siete lecciones: Campo y potencial electrostático en el vacío, Estudio de conductores en equilibrio, Estudio de medios dieléctricos, Corrientes eléctricas estacionarias, Campo magnético estático, Inducción electromagnética y Circuitos de corriente alterna. Tras una breve introducción, el autor explica los conceptos, principios y teorías de cada tema, utilizando ejemplos aclaratorios en los casos oportunos.

¿Cuánto contaminará una central térmica que funciona con fuel? : un ejemplo de resolución de problemas como investigación.

Resumen tomado de la publicación

Instalador de sistemas de energía solar térmica.

Real Decreto 2223, de 19 de mayo de 1998 por el que se establece el certificado de profesionalidad de la ocupación de instalador de sistemas de energía solar térmica acompañado de dos anexos, uno sobre el referente ocupacional que incluye datos y denominación de la ocupación, familia profesional a la que pertenece, perfil y competencias profesionales,el otro sobre el referente formativo que presenta de forma esquematizada los contenidos teórico-prácticos, los módulos que lo componen y su duración, objetivos específicos y criterios de evaluación.

Sistema virutal de apoyo para el aprendizaje de la ingeniería térmica.

Convocatoria a los Premios Nacionales de Investigación e Innovación Educativas 2005. Modalidad de Innovación Educativa. Mención Honorífica

Treatment of nonlinear optical properties due to large amplitude anharmonic vibrational motions: umbrella motion in NH3

A general reduced dimensionality finite field nuclear relaxation method for calculating vibrational nonlinear optical properties of molecules with large contributions due to anharmonic motions is introduced. In an initial application to the umbrella (inversion) motion of NH3 it is found that difficulties associated with a conventional single well treatment are overcome and that the particular definition of the inversion coordinate is not important. Future applications are described

The use of pulse amplitude modulated fluorescence techniques for metal toxicity assessment in fluvial biofilms

Metal pollution in rivers is in great concern with human activities in the fluvial watershed. This thesis aims to investigate the potential use of chl-a fluorescence parameters as biomarkers of metal toxicity, and to find cause-effect relationships between metal exposures, other environmental factor (i.e. light), and functional and structural biofilm responses. This thesis demonstrates that the use of chl-a fluorescence parameters allows detect early effects on biofilms caused by zinc toxicity, both in the laboratory as in polluted rivers. In microcosm experiments, the use of chl-a fluorescence parameters allows evaluates structural changes on photosynthetic apparatus and in algal groups’ composition of biofilms long-term exposed to zinc. In order to evaluate the effects of chronic metal pollution in rivers, it is recommended the use of biofilm translocation experiments and the use of a multi-biomarker approach.

Unimodality of wave amplitude in the northern Hemisphere

A novel statistic for local wave amplitude of the 500-hPa geopotential height field is introduced. The statistic uses a Hilbert transform to define a longitudinal wave envelope and dynamical latitude weighting to define the latitudes of interest. Here it is used to detect the existence, or otherwise, of multimodality in its distribution function. The empirical distribution function for the 1960-2000 period is close to a Weibull distribution with shape parameters between 2 and 3. There is substantial interdecadal variability but no apparent local multimodality or bimodality. The zonally averaged wave amplitude, akin to the more usual wave amplitude index, is close to being normally distributed. This is consistent with the central limit theorem, which applies to the construction of the wave amplitude index. For the period 1960-70 it is found that there is apparent bimodality in this index. However, the different amplitudes are realized at different longitudes, so there is no bimodality at any single longitude. As a corollary, it is found that many commonly used statistics to detect multimodality in atmospheric fields potentially satisfy the assumptions underlying the central limit theorem and therefore can only show approximately normal distributions. The author concludes that these techniques may therefore be suboptimal to detect any multimodality.

Movement time for motion-impaired users assisted by force-feedback: effects of movement amplitude, target width and gravity well width

This paper presents a study investigating how the performance of motion-impaired computer users in point and click tasks varies with target distance (A), target width (W), and force-feedback gravity well width (GWW). Six motion-impaired users performed point and click tasks across a range of values for A, W, and GWW. Times were observed to increase with A, and to decrease with W. Times also improved with GWW, and, with the addition of a gravity well, a greater improvement was observed for smaller targets than for bigger ones. It was found that Fitts Law gave a good description of behaviour for each value of GWW, and that gravity wells reduced the effect of task difficulty on performance. A model based on Fitts Law is proposed, which incorporates the effect of GWW on movement time. The model accounts for 88.8% of the variance in the observed data.

Radiometric analysis of the light coupled by optimally cut plastic optical fiber amplitude modulating reflectance displacement sensors

A radiometric analysis of the light coupled by optical fiber amplitude modulating extrinsic-type reflectance displacement sensors is presented. Uncut fiber sensors show the largest range but a smaller responsivity. Single cut fiber sensors exhibit an improvement in responsivity at the expense of range. A further increase in responsivity as well as a reduction in the operational range is obtained when the double cut sensor configuration is implemented. The double cut configuration is particularly suitable in applications where feedback action is applied to the moving reflector surface. © 2000 American Institute of Physics.