Hallazgos electromiográficos y electroneurográficos en el pie cavo esencial

La etiología del pie cavo cuando ésta es conocida, suele ser debida a un trastorno de tipo neurológico o miopático, aunque en determinados casos nos encontramos con pacientes que padecen esta deformidad en el pie, en los cuales no podemos descubrir ningún antecedente de este tipo, por lo que lo calificamos de pie cavo «esencial». A un grupo de estos pacientes con pie cavo «esencial», en los que no hemos encontrado ningún tipo de antecedente neurológico, lo hemos sometido a una exploración electroneurográfica, encontrando que la mitad de ellos padecían algún trastorno neuropático/miopático, que no había sido detectado en la exploración clínica inicial.Neurological or myopathic diseases are frequently involved in the etiology of flat foot. In some cases, no antecedents of disease can be found and therefore these flat foots are classified as «essential». We have undertaken an electrophysiologic study in a series of patients with «essential» flat food in order to explore unsuspected neurological disorders. In half of the patients, neuropathic and myopathic electroneurographic patterns of different severity were detected

Thermal transport in glassy selenium: The role of low-frequency librations

7 págs.; 3 figs.The experimental curves giving the temperature dependence of the thermal conductivity of glassy selenium are considered in detail. The observed behavior can be taken into account quantitatively if the densities of states for short-wavelength phonons as well as for low-energy librations arising from computer simulations are used for the calculations. In particular, it is shown that the lowest frequency excitations of a chain of selenium atoms can give due account of the plateau observed at temperatures about 2-10 K. The implications of the present findings for the current debate regarding the mechanisms for thermal transport in glasses are finally discussed. © 1994 The American Physical Society.This work has been supported by DGICYT Grant No. PB92-0114-C03Peer Reviewe

Thermal transport in glassy selenium: The role of low-frequency librations

The experimental curves giving the temperature dependence of the thermal conductivity of glassy selenium are considered in detail. The observed behavior can be taken into account quantitatively if the densities of states for short-wavelength phonons as well as for low-energy librations arising from computer simulations are used for the calculations. In particular, it is shown that the lowest frequency excitations of a chain of selenium atoms can give due account of the plateau observed at temperatures about 2-10 K. The implications of the present findings for the current debate regarding the mechanisms for thermal transport in glasses are finally discussedDirección General de Investigación Científica y Técnica PB92-0114-C0

Obstáculos y dificultades de los maestros en formación inicial en el diseño de unidades didácticas de enfoque investigador: el inventario general de obstáculos

La planificación de la enseñanza constituye un momento de máxima relevancia entre las tareas profesionales del docente. Realizando el análisis de estos procesos y sus resultados con cierto detenimiento, se pueden poner de manifiesto muchas de las opciones didácticas del profesor y aquellos aspectos que actúan como obstáculos cuando reflexiona sobre los objetivos, contenidos, actividades y demás elementos curriculares que debe incluir en el diseño de una determinada unidad didáctica. Los estudios sobre los procesos de planificación de unidades didácticas por los profesores constituyen una línea investigación didáctica muy interesante, por ser próxima a la práctica profesional y proporciona contextos adecuados para el estudio de las barreras en el desarrollo profesional docente, que centra nuestra investigación

GPS, LiDAR and VNIR data to monitor the spatial behavior of grazing sheep

Traditional knowledge about the behavior of grazing livestock is about to disappear. Shepherds well know that sheep behavior follows non-random patterns. As a novel alternative to seeking behavioral patterns, this study quantified the grazing activities of two sheep flocks of Churra breed (both in the same area but separated by 10 years) based on Global Position System (GPS) monitoring and remote monitoring sensing techniques. In the first monitoring period (2009-10), geolocations were recorded every 5 min (4, 240 records), while in the second one (2018-20), records were taken every 30 min (7, 636 records). The data were clustered based on the day/night and the activity (resting, moving, or grazing). An airborne LiDAR dataset was used to study the slope, aspect, and vegetation height. Four visible-infrared orthophotographs were mosaicked and classified to obtain the land use/land cover (LU/LC) map. Then, GPS locations were overlain on the terrain features, and a Chi-square test evaluated the relationships between locations and terrain features. Three spatial statistics (directional distribution, Kernel density, and Hot Spot analysis) were also calculated. Results in both monitoring periods suggested that the spatial distribution of free-grazing ewes was non-random. The flocks showed strong preferences for grazing areas with gentle north-facing slopes, where the herbaceous layer formed by pasture predominates. The geostatistical analyses of the sheep locations corroborated those preferences. Geotechnologies have emerged as a potent tool to demonstrate the influence of environmental and terrain attributes on the non-random spatial behavior of grazing sheep. © 2022 Malque Publishing. All rights reserved

Cortistain is expressed in a distinct subset of cortical interneurons

Cortistatin is a presumptive neuropeptide that shares 11 of its 14 amino acids with somatostatin. In contrast to somatostatin, administration of cortistatin into the rat brain ventricles specifically enhances slow wave sleep, apparently by antagonizing the effects of acetylcholine on cortical excitability. Here we show that preprocortistatin mRNA is expressed in a subset of GABAergic cells in the cortex and hippocampus that partially overlap with those containing somatostatin. A significant percentage of cortistatin-positive neurons is also positive for parvalbumin. In contrast, no colocalization was found between cortistatin and calretinin, cholecystokinin, or vasoactive intestinal peptide. During development there is a transient increase in cortistatin-expressing cells in the second postnatal week in all cortical areas and in the dentate gyrus. A transient expression of preprocortistatin mRNA in the hilar region at P16 is paralleled by electrophysiological changes in dentate granule cells. Together, these observations suggest mechanisms by which cortistatin may regulate cortical activity

Low-frequency excitations in glassy selenium: A comparison of neutron-scattering and molecular-dynamics results

The microscopic low-frequency dynamics of glassy selenium is investigated by means of the concurrent use of neutron inelastic scattering and computer simulations. A separation of the dynamic response in terms of intra- and interchain processes is achieved from the analysis of the simulation results. The S(Q,E) dynamic structure factors are analyzed in terms of the frequency moments or from a model scattering law, and the wave-vector dependence of the relevant quantities is established. Finally, the anomalous behavior of the heat capacity at moderately low temperatures is shown to be originated by mostly interchain interactions.Dirección General de Investigación Científica y Técnica PB89-0037-C

Low-frequency excitations in glassy selenium: A comparison of neutron-scattering and molecular-dynamics results

12 págs.; 9 figs.; 1 tab.The microscopic low-frequency dynamics of glassy selenium is investigated by means of the concurrent use of neutron inelastic scattering and computer simulations. A separation of the dynamic response in terms of intra- and interchain processes is achieved from the analysis of the simulation results. The S(Q,E) dynamic structure factors are analyzed in terms of the frequency moments or from a model scattering law, and the wave-vector dependence of the relevant quantities is established. Finally, the anomalous behavior of the heat capacity at moderately low temperatures is shown to be originated by mostly interchain interactions. © 1993 The American Physical Society.This work has been supported in part by DGICYT Grant No. PB89-0037-C03.Peer Reviewe