Entropy, purity and optical hysteresis in markovian optical modes.

We describe the synthesis of optical modes whose axial structure follows a random tandem array of Bessel beams of integer order. The array follows fluctuations of Markov-chain type and the amplitude values for each beam are linked to a sequence of random vectors. As a prototype, we describe the synthesis of optical fields for Markov-chain type Ehrenfest. This process models the thermodynamic equilibrium and then it can be related to the evolution and stability of optical systems, in this way, it offers a similitude with partially coherent processes where the coherence degree is now distributed between all the compounds of the resulting random vector. The matrix representation for the stochastic process allows incorporating entropy properties and the calculus of the purity for the optical field. This constitutes the basis to describe the interference between markovian modes. When the set of markovian modes type Ehrenfest reaches a stable configuration they become indistinguishability non-conservative optical field having associated hysteresis features. Computer simulations are presented.

Invariant correlated optical fields driven by multiplicative noise.

We describe the evolution of a linear transmittance when it is perturbed with multiplicative noise; the evolution is approximated through an ensemble of random transmittances that are used to generate diffraction fields. The randomness induces a competition mechanism between noise and transmittance, and it is identified through the self-correlation function. We show that the geometry of the self-correlation function is a single peak preserved in the diffraction field that can be matched with localization-like effects. To corroborate the theoretical predictions, we perform an experiment using a linear grating where the noise is approximated by a stochastic Markov chain. Experimental results are shown.

Actuación ante una epistaxis

La epistaxis es la patología otorrinolaringológica más frecuente atendida en urgencias. En el siguiente artículo se expone su localización anatómica, etiopatogenia, sintomatología clínica, así como las posibles complicaciones. También trataremos el procedimiento diagnóstico, basado fundamentalmente en la exploración y los diferentes modos terapéuticos, los cuales, aunque específicos del especialista, deben ser conocidos y aplicados por cualquier médico adscrito a un servicio de urgencias (AU)

[Effectiveness of tonsillectomy, evaluated by acoustic rhinometry]. / Eficacia de la adenoidectomía evaluada mediante rinometría acústica.

Hypertrophy adenoid commonest cause of nasal obstruction in paediatrics. The morbility can be try alteration in the respiratory physiology, as well as in the face development and function of the middle ear. We used the acoustic rhinometry to evaluate the surgical results of the adenoidectomy in children with hypertrophy adenoid, compiling the data on their clinic, and correlating them as well with the rhinometric results. The acoustic rhinometry is a relatively new method of exploration of the nasal cavity. We obtain space measures that are going to allow to us to prove it. These measures are the cross-sectional areas and volumes registered in the nasal cavity when this cavity is divided longitudinally in two zones, the previous one until 32 mm measured from the narina, and the later one to 64 mm from the same point. For this study we have taken 45 patients with hypertrophied adenoids. We have made measurements pre and post surgery. Our results show a clear gain in areas as in volumes after surgery and also show the utility of the acoustic rhinometry like method of exploration at the time of quantifying the morphometric alterations of the nasal cavity.

[Cold tuberculous retropharyngeal abscess]. / Absceso frio retrofaringeo de estirpe tuberculosa.

The AA. present a report about a patient having a cold tuberculous abscess which symptomatologic manifested through dysphagia and cervico-brachialgia. Comments on the most remarkable aspects of these conditions.

Morphological variations of human ossicula tympani.

In a series of 100 cases, morphological variations of human ossicula tympani were studied. These have seldom been considered either in classic or recent descriptions. Among them, the malleus and stapes are the most variable ones. A geometric model is proposed to systematically study any variation from the typical ossicles. These morphological variations of ossicles could be related to age, sex, race, and could bring out peculiarities in acoustic transmission.