Videolaringoestroboscopia: una técnica para visualizar las cuerdas vocales

Para estudiar las distintas alteraciones de la voz, el laringólogo se ha fundamentado en la exploración indirecta de las cuerdas vocales. De entre las distintas posibilidades exploratorias, la estroboscopia laríngea es hoy por hoy la principal herramienta clínica para el diagnóstico etiológico de los trastornos de la voz, porque permite analizar imágenes de la laringe en alta resolución y simultáneamente aporta datos sobre el patrón vibratorio de la mucosa vocal. La videoestroboscopia no es más que una técnica especial de iluminación de las cuerdas vocales por emisión flashes cortos de luz de forma sincronizada o asincronizada con la frecuencia fundamental, lo que permite visualizar el movimiento de ondulación de la mucosa vocal a cámara lenta. La exploración estroboscópica permite examinar la laringe a diferente tono, intensidad y calidad de voz. Los parámetros que se evalúan en el estudio estroboscópico son los siguientes: frecuencia fundamental, simetría de los movimientos de cierre/apertura de las cuerdas vocales, regularidad o periodicidad de las vibraciones, cierre glótico, amplitud del desplazamiento horizontal de las cuerdas vocales, y las características y grado de ondulación de la mucosa vocal. A lo largo del presente taller de trabajo se detallará la metodología exploratoria que se realiza en el marco clínico de la consulta otorrinolaringológica, presentándose ejemplos de un amplio número de exploraciones normales y patológicas.Classically, the laryngologists have based the study of the voice problems on the indirect examination of the vocal cords by means of a larynx mirror. However, this examination only considers the gross respiratory movements of the vocal folds, i.e., abduction and adduction. To analyze the problems responsible for voice disorders, the small vibratory movements of the vocal cords should be assessed. Nowadays, the stroboscopic examination of the larynx is the best way to analyze the vibratory pattern of the vocal folds during phonation. The vocal folds are illuminated by short light flashes of the same frequency of the vibrations in a synchronic or asynchronic way, in order to visualize the mucosal vibration in slow motion. Laryngeal stroboscopy gives the opportunity to examine every subject at different pitch, intensity, and quality of voice. Several parameters may be assessed, including fundamental frequency, glottic closure, phase and amplitude symmetry, and also the characteristics of the mucosal wave. The present workshop is primarily aimed to describe the examination methodology used in a clinical otorlaryngology setting. A large number of normal and pathologic examinations will be discussed.Para estudiar las distintas alteraciones de la voz, el laringólogo se ha fundamentado en la exploración indirecta de las cuerdas vocales. De entre las distintas posibilidades exploratorias, la estroboscopia laríngea es hoy por hoy la principal herramienta clínica para el diagnóstico etiológico de los trastornos de la voz, porque permite analizar imágenes de la laringe en alta resolución y simultáneamente aporta datos sobre el patrón vibratorio de la mucosa vocal. La videoestroboscopia no es más que una técnica especial de iluminación de las cuerdas vocales por emisión flashes cortos de luz de forma sincronizada o asincronizada con la frecuencia fundamental, lo que permite visualizar el movimiento de ondulación de la mucosa vocal a cámara lenta. La exploración estroboscópica permite examinar la laringe a diferente tono, intensidad y calidad de voz. Los parámetros que se evalúan en el estudio estroboscópico son los siguientes: frecuencia fundamental, simetría de los movimientos de cierre/apertura de las cuerdas vocales, regularidad o periodicidad de las vibraciones, cierre glótico, amplitud del desplazamiento horizontal de las cuerdas vocales, y las características y grado de ondulación de la mucosa vocal. A lo largo del presente taller de trabajo se detallará la metodología exploratoria que se realiza en el marco clínico de la consulta otorrinolaringológica, presentándose ejemplos de un amplio número de exploraciones normales y patológicas

La Société Civile et le droit de l'environnement. Contribution à la réflexion sur les sources et la validité des normes juridiques

POMADE, Adélie, La Société Civile et le droit de l'environnement. Contribution à la réflexion sur les sources et la validité des normes juridiques, Lextenso, DL, París, 2010,716 pp

Incidencia de una semana de docencia en la fonación de los profesores

En este artículo se presenta, por un lado, una valoración subjetiva de los propios profesores sobre sus características vocales a partir de un resumen del Voice Handicap Index (VHI) (Jacobson et alii, 1997), un cuestionario rigurosamente validado. Concretamente se evalúa la percepción del propio profesor sobre su discapacidad vocal a partir de la versión reducida VHI-10 (Rosen et alii, 2004). De forma complementaria, se ofrecen los resultados de un análisis objetivo de diferentes parámetros (jitter, shimmer, relación armónicos-ruido, duración o F0 media, etc). Los informantes son docentes que trabajan en colegios de Madrid y Barcelona, en un abanico de niveles educativos que cubre enseñanza infantil, primaria, ESO y bachillerato. Este trabajo, que se inserta en el marco de una investigación más amplia, presenta los resultados obtenidos en una semana lectiva al finalizar el primer trimestre académico, a partir de muestras tomadas en lunes y en viernes, relacionando las variables objetivas y subjetivas mencionadas. Palabras clave: esfuerzo vocal; valoración objetiva y subjetiva de la fonación; análisis acústico; cualidad de voz; uso profesional de la voz; docencia y fonación.This paper presents, on one side, a subjective assessment of 72 teachers on their vocal characteristics from a summary of the Voice Handicap Index (VHI) (Jacobson et alii, 1997), a rigorously validated questionnaire. More precisely, we used the short version, also validated, VHI-10 (Rosen et alii, 2004). And, on the other side, an objective analysis of different parameters (jitter, shimmer, harmonic to noise ratio, durations, average F0, etc.) was done. The participants are teachers in Madrid and Barcelona, from pre-school to high school levels. This paper, a part of a most wide work, presents the results obtained in a school week at the end of the first academic quarter, from samples taken in Monday and Friday, considering the objective and subjective above variables. Keywords: vocal effort; subjective and objective fonation assessment; acoustic analysis; voice quality; professional voice use; teaching and phonation

Fractal dimension of the trajectory of a single particle diffusing in crowded media

Using Monte Carlo simulations we have modeled the diffusion of a single particle in twoand three-dimensional lattices with different crowding conditions given by distinct obstacles size and density. All registered data emphasize that diffusion process is anomalous and diffusing particle describes fractal trajectories. We have introduced a new time-scale fractal dimension, dm, which is related to the anomalous diffusion exponent, α. This allows us to relate the well-known length-scale fractal dimension of the random walk, dw, to the new one introduced here as a time-scale fractal dimension. Moreover, the 3D simulations consider similar conditions to those used in our previous FRAP experiments in order to reveal the relationship between the length and time-scale fractal dimensions

BIOFUMIGACIÓN Y BIOSOLARIZACIÓN EN EL CONTROL DEL ToMV: UNA BUENA ALTERNATIVA AL BROMURO DE METILO

Crop residues are often an important source of insects, mites and phytopathogenic agents avoiding their presence in the fi eld. Nevertheless, the process of composting in the soil by means of biofumigation and biosolarization can help to control these agents depending of some factors as temperature, time of treatment, implicated microorganisms and the kind of soil. This research deals about the use of biofumigation and biosolarization for the control of Tomato mosaic virus (ToMV) under controlled conditions in pots and 3 different doses of infected vegetal material with the virus were used. Cocopeat slabs infected with the virus were used, too. These growbags had been used during one year and the virus was detected on the remained roots. Both pots and growbags were placed in open or shut plastic bags and were treated at different temperatures during different periods of time. The treatment at 25 ºC was considered as biofumigation and the treatment at 45 ºC was considered as biosolarization. Since 4 weeks of treatment at 45 ºC was suffi cient to control ToMV in pots, biosolarization was more effective than biofumigation. 6 weeks of treatment at 25 ºC were necessary to control the virus. In growbags, 5 weeks of treatment at 45 ºC were not suffi cient to control the virus, but the percentage of infected plants was reduced and a greater development and premature fl owering period were observed. Biofumigation and biosolarization can be considered as alternative techniques for the use of Methyl Bromide for the control of phytopathogenic agents.Los restos de cosechas son a menudo portadores de insectos, ácaros y agentes de fi topatógenos, desaconsejando su presencia en campo. Sin embargo el proceso de compostaje en el interior del suelo mediante los procesos de biofumigación y biosolarización, favorecen el control de estos agentes en función de la temperatura, tiempo, microorganismos implicados, plantas empleadas y características del suelo. Este trabajo determinó, en condiciones controladas, la efi cacia de la biofumigación y biosolarización en el control del virus del mosaico del tomate en macetas empleando 3 dosis de material vegetal infectado con el virus y en mangas de fi bra de coco de un año de uso donde quedaban restos de raíces del cultivo anterior infectadas con el virus. Tanto las macetas como las mangas de fibra de coco fueron sometidas a diferentes tratamientos de embolsado, no embolsado y tiempo de tratamiento. Se consideró biofumigación al tratamiento con 25 ºC y biosolarización al tratamiento con 45 ºC. Los resultados obtenidos demuestran la eficacia de la biosolarización en el control del virus en macetas sobre la biofumigación; ya que tan solo 4 semanas de tratamiento fueron sufi cientes frente a las 6 semanas necesarias en la biofumigación. En las mangas de fibra de coco la biosolarización durante 5 semanas resultó ineficaz para el control del virus, pero se redujo el porcentaje de plantas infectadas y se observó un mayor desarrollo vegetativo y el adelanto en su fl oración. La biofumigación y biosolarización pueden ser consideradas como técnicas alternativas al uso del Bromuro de metilo en el control de agentes fitopatógenos

Cavity solitons in bidirectional lasers

We show theoretically that a broad area bidirectional laser with slightly different cavity losses for the two counterpropagating fields sustains cavity solitons (CSs). These structures are complementary, i.e., there is a bright (dark) CS in the field with more (less) losses. Interestingly, the CSs can be written/erased by injecting suitable pulses in any of the two counterpropagating fields.Comment: 4 figure

New insights into diffusion in 3D crowded media by Monte Carlo simulations: Effect of size, mobility and spatial distribution of obstacles

Particle diffusion in crowded media was studied through Monte Carlo simulations in 3D obstructed lattices. Three particular aspects affecting the diffusion, not extensively treated in three-dimensional geometry, were analysed: the relative particle-obstacle size, the relative particle-obstacle mobility and the way of having the obstacles distributed in the simulation space (randomly or uniformly). The results are interpreted in terms of the parameters that characterize the time dependence of the diffusion coefficient: the anomalous diffusion exponent (), the crossover time from anomalous to normal diffusion regimes (τ) and the long time diffusion coefficient (D*). Simulation results indicate that there is a more anomalous diffusion (smaller ) and lower long time diffusion coefficient (D*) when obstacle concentration increases, and that, for a given total excluded volume and immobile obstacles, the anomalous diffusion effect is less important for bigger size obstacles. However, for the case of mobile obstacles, this size effect is inverted yielding values that are in qualitatively good agreement with in vitro experiments of protein diffusion in crowded media. These results underline that the pattern of the spatial partitioning of the obstacle-excluded volume is a factor to be considered together with the value of the excluded volume itself

Diffusion in macromolecular crowded media. Monte Carlo simulation of obstructed diffusion vs. FRAP experiments

The diffusion of tracer particles in 3D macromolecular crowded media has been studied using two methodologies, simulation and experimental, with the aim of comparing their results. Firstly, the diffusion of a tracer in an obstructed 3D lattice with mobile and big size obstacles has been analyzed through a Monte Carlo (MC) simulation procedure. Secondly, Fluorescence Recovery after Photobleaching (FRAP) experiments have been carried out to study the diffusion of a model protein (alpha-chymotrypsin) in in vitro crowded solution where two type of Dextran molecules are used as crowder agents. To facilitate the comparison the relative size between the tracer and the crowder is the same in both studies. The results indicate a qualitative agreement between the diffusional behaviors observed in the two studies. The dependence of the anomalous diffusion exponent and the limiting diffusion coefficient with the obstacle size and excluded volume shows, in both cases, a similar tendency. The introduction of a reduced mobility parameter in the simulation model accounting for the short range tracer-obstacle interactions allows to obtain a quantitative agreement between the limiting diffusion coefficient values yielded by both procedures. The simulation-experiment quantitative agreement for the anomalous diffusion exponent requires further improvements. As far as we know, this is the first reported work where both techniques are used in parallel to study the diffusion in macromolecular crowded media

Effect of crowding by dextrans on the hydrolysis of N-Succinyl-L-phenyl-Ala-p-nitroanilide catalyzed by α-chymotrypsin

Traditionally, studies on the diffusion-controlled reaction of biological macromolecules have been carried out in dilute solutions (in vitro). However, in an intracellular environment (in vivo), there is a high concentration of macromolecules, which results in nonspecific interactions (macromolecular crowding). This affects the kinetics and thermodynamics of the reactions that occur in these systems. In this paper, we study the crowding effect of large macromolecules on the reaction rates of the hydrolysis of N-succinyl-L-phenyl-Ala-p-nitroanilide catalyzed by R-chymo- trypsin, by adding dextrans of various molecular weights to the reaction solutions. The results indicate that the volume occupied by the crowding agent, but not its size, plays an important role in the rate of this reaction. A vmax decay and a Km increase were obtained when the dextran concentration in the sample was increased. The increase in Km can be attributed to the slowing of protein diffusion, due to the presence of crowding. Whereas the decrease in vmax could be explained by the effect of mixed inhibition by product, which is enhanced in crowded media. As far as we know, this is the first reported experiment on the crowding effect in an enzymatic reaction with a mixed inhibition by product

Diffusion of alpha-Chymotrypsin in solution-crowded media. A fluorescence recovery after photobleaching study

Fluorescence Recovery after Photobleaching (FRAP) is one of the most powerful and used techniques to study diffusion processes of macromolecules in membranes or in bulk. Here, we study the diffusion of alpha-chymotrypsin in different crowded (Dextran) in vitro solutions using a confocal laser scanning microscope. In the considered experimental conditions, confocal FRAP images could be analyzed applying the uniform circular disc approximation described for a nonscanning microscope generalized to take into account anomalous diffusion. Considering the slow diffusion of macromolecules in crowded media, we compare the fitting of confocal FRAP curves analyzed with the equations provided by the Gaussian and the uniform circular disc profile models for nonscanning microscopes. As the fitted parameter variation with the size and concentration of crowders is qualitatively similar for both models, the use of the uniform circular disc or the Gaussian model is justified for these experiments. Moreover, in our experimental conditions, alpha-chymotrypsin shows anomalous diffusion (a < 1), depending on the size and concentration of Dextran molecules, until a high concentration and high size of crowding agent are achieved. This result indicates a range of validity of the idealized fitting expressions used, beyond of which other physical phenomena must be considered