A reduced-order-model-based equivalent circuit for piezoelectric micro-electro-mechanical-system loudspeakers modeling.

Piezoelectric micro-electro-mechanical-system (MEMS) speakers are emerging as promising implementations of loudspeakers at the microscale, as they are able to meet the ever-increasing requirements for modern audio devices to become smaller, lighter, and integrable into digital systems. In this work, we propose a finite element model (FEM)-assisted lumped-parameters equivalent circuit for a fast and accurate modeling of these types of devices. The electro-mechanical parameters are derived from a pre-stressed FEM eigenfrequency analysis, to account for arbitrarily complex geometries and for the shift of the speaker resonance frequency due to an initial non-null pre-deflected configuration. The parameters of the acoustical circuit are instead computed through analytical formulas. The acoustic short-circuit between the speaker front and rear sides is taken into account through a proper air-gaps modeling. The very good matching in terms of radiated sound pressure level among the equivalent circuit predictions, FEM simulations, and experimental data proves the ability of the proposed method to accurately simulate the speaker performance. Moreover, due to its generality, it represents a versatile tool for designing piezoelectric MEMS speakers.

Experimental acoustic scene analysis using One-Eighth spherical fraction microphone array.

This paper investigates the performance of one-eighth Spherical Fraction Microphone Array through experimental measurement to analyze acoustic scenes in one-eighth of space. The array geometry is designed to be placed in a room corner at the junction of three acoustically rigid walls. Two prototypes are built with 8 and 16 microphones, respectively. The sampling strategy is discussed and a spatial aliasing analysis is carried out both analytically and by numerical simulations. The array performances are evaluated through Spherical Fraction Beamforming (SFB). This approach is based on the decomposition of the acoustic pressure field in a rigid bounded domain. The localization angular error and Directivity Index criterion are evaluated for both arrays. In a first experiment, the arrays are mounted in an eighth of space built inside an anechoic room. The results are compared with simulation and show consistency. The theoretical limitations of SFB in a rigid bounded one-eighth of space are retrieved experimentally. These limitations are also observed in a real configuration: an office room. Further investigations on SFB are also conducted in the case of a virtual scene constructed with two sound sources.

Infección neumocócica en Pediatría. De la clínica al laboratorio / Pediatric pneumococcal infection. From clinics to laboratory

Streptococcus pneumoniae es uno de los patógenos de mayor relevancia en las enfermedades infecciosas. En estos últimos años hemos desarrollado en el Hospital Virgen del Rocío una línea de investigación sobre la infección neumocócica en Pediatría con un abordaje integral y multidisciplinario. LA introducción de técnicas de serotipación y genotipación molecular en muestras clínicas nos permitió analizar los factores asociados al incremento de la incidencia del empiema pleural pediátrico, que se relacionó con una onda epidérmica por expansión de la clona ST306 del serotipo 1 neumocócico. En un estudio de portadores nasofaríngeos se observaron incrementos significativos de lo largo del tiempo de los serotipos 15B/C y 19ª, que se siguieron con el adloramiento de este último serotipo como causa importante de enfermedad invasora neumocócica en nuestro medio. Finalmente, hemos establecido una línea de colaboración con grupos de investigación básica para el desarrollo de una metodología experimental basada en una combinación de estrategias proteómicas con el objetivo de descubrir nuevos candidatos proteicos para el desarrollo de vacunas y plataformas diagnósticas frente a la infección por S. pneumoniae (AU)

Streptococcus pneumoniae is one of the most important pathogens in infectious diseases. We have been conducting several research projects on pneumococcal infection in children at the University Hospital Virgen del Rocío during recent years and they were based on a multidisciplinary and comprehensive approach. The introduction of molecular techniques allowed to identify the serotypes and genotypes causing pediatric pleural empyema (PPE) and relate these data to disease increasing incidence. This was partly due to clonal expansion of the genotype ST306 associated to pneumococcal serotype 1. Significant increases of serotypes 15B/C and 19A were observed over time in nasopharyngeal carriage and they anticipated the emergence of the latter serotype in pneumococcal invasive disease. Finally, we have been collaborating with basic researchers on the development of a methodology based on a combination of proteomic strategies to identify new protein vaccine candidates and to validate diagnostic platforms for prevention and diagnosis of pneumococcal infectionsv (AU)

Application of multicriteria decision analysis to jar-test results for chemicals selection in the physical-chemical treatment of textile wastewater.

Jar-test is a well-known tool for chemicals selection for physical-chemical wastewater treatment. Jar-test results show the treatment efficiency in terms of suspended matter and organic matter removal. However, in spite of having all these results, coagulant selection is not an easy task because one coagulant can remove efficiently the suspended solids but at the same time increase the conductivity or increase considerably the sludge production containing chemicals and toxic dyes. This makes the final selection of coagulants very dependent on the relative importance assigned to each measured parameter. In this paper, the use of multicriteria decision analysis (MCDA) is proposed to help on the selection of the coagulant and its concentration in the physical-chemical wastewater treatment, since textile wastewater contains hazardous substances. Therefore, starting from the parameters fixed by the jar-test results, these techniques will allow to weight these parameters, according to the judgements of wastewater experts, and to establish priorities among coagulants. Two well-known MCDA techniques have been used: analytic hierarchic process (AHP) and preference ranking organization method for enrichment evaluations (PROMETHEEs) and their results were compared. The method proposed has been applied to the particular case of textile wastewaters. The results obtained show that MCDA techniques are useful tools to select the chemicals for the physical-technical treatment.

Nosocomial outbreak due to a multiresistant strain of Pseudomonas aeruginosa P12: efficacy of cefepime-amikacin therapy and analysis of beta-lactam resistance.

Over a 3-year period, 67 patients of the Hospital of Pau (Pau, France), including 64 patients hospitalized in the adult intensive care unit (ICU), were colonized and/or infected by strains of Pseudomonas aeruginosa P12, resistant to all potentially active antibiotics except colistin. Most patients were mechanically ventilated and presented respiratory tract infections. Since cefepime and amikacin were the least inactive antibiotics by MIC determination, all ICU patients were treated with this combination, and most of them benefited. Cefepime-amikacin was found highly synergistic in vitro. Ribotyping and arbitrary primer-PCR analysis confirmed the presence of a single clonal isolate. Isoelectrofocusing revealed that the epidemic strain produced large amounts of the chromosomal cephalosporinase and an additional enzyme with a pI of 5.7, corresponding to PSE-1, as demonstrated by PCR and sequencing. Outer membrane protein profiles on sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed the absence of a ca. 46-kDa protein, likely to be OprD, and increased production of two ca. 49- and 50-kDa proteins, consistent with the outer membrane components of the efflux systems, MexAB-OprM and MexEF-OprN. Thus, we report here a nosocomial outbreak due to multiresistant P. aeruginosa P12 exhibiting at least four mechanisms of beta-lactam resistance, i.e., production of the penicillinase PSE-1, overproduction of the chromosomal cephalosporinase, loss of OprD, and overexpression of efflux systems, associated with a better activity of cefepime than ceftazidime.

[Adenoid cystic carcinoma of the minor salivary glands. Our experience]. / Carcinoma adenoide quístico de glándulas salivares menores. Nuestra experiencia.

Adenoid cystic carcinoma is the most frequent malignant tumor of the minor salivary glands. It is characterized by a slow, but aggressive, clinical evolution, which tends to produce distant metastases even years after the initial surgical treatment. We present a clinical study of 19 patients with adenoid cystic carcinoma of the minor salivary glands that were treated with surgery and radiotherapy. The survival (vital) prognosis for this study declined in the third year after initial treatment, with recurrence and distant metastases occurring several years after treatment. Therefore, the clinical course of this disease requires long-term follow-up of patients.

[Objective evaluation of vocal pathology in childhood]. / Evaluación objetiva de la patología vocal en la infancia.

Voice disorders in children are often described as existing on a continuum with anatomic or physiologic causes at one end and functional or psychogenic causes at the other. In this study we report the objective evaluation of the voice disorders on 48 school children. The evaluation was made by means of laryngostroboscopy, acoustic analysis of the voice and narrow-band spectrography. The stroboscopic examination was performed on more than a half of the patients, resulting in the change of diagnose in six cases. The severity of the hoarseness was classified in four groups according Yanagihara method. A multivariate analysis was carried out using jitter, shimmer and harmonic-to-noise ratio as variables. Only the harmonic-to-noise ratio predicts the severity of the spectrographic record. Classification of degrees of hoarseness is found to be clinically useful in two respects: the degree of hoarseness can be numerically expressed and the objective acoustic degree of hoarseness based on this method closely agrees with subjective perceived degree of hoarseness.

[Paragangliomas of the head and neck. Our experience]. / Paragangliomas de cabeza y cuello. Nuestra experiencia.

Paragangliomas of the head and neck are rare tumors of neuroectodermal origin. However, jugulotympanic paragangliomas are the second most common tumor of the temporal bone. Paragangliomas are recognized as benign tumors, but some show a biological behavior similar to that of malignant lesions, such as the development of recurrence or invasive growth patterns. We report 31 patients with a total of 35 paragangliomas who were seen in our department. Multiple paragangliomas were found in 2 patients. Twenty-two patients had jugulotympanic paragangliomas, 11 carotid and 2 vagal paragangliomas. None of the patients had prior treatment and the minimum follow-up was 1 year. Surgery was performed in 28 (90%), primary irradiation in 1 (3%), and 2 (7%) refused treatment. We describe our results, the clinical course, diagnostic methods and treatment options.

[Comparative in vitro activity of cefepime: multicenter study in Aquitaine]. / Activité in vitro comparée du céfépime: étude multicentrique en Aquitaine.

Over a 6 month-period (1st January to 30th June 1995), the results of antibiotic susceptibility testing routinely performed for beta-lactams against enterobacteria, Pseudomonas aeruginosa, and Acinetobacter in 7 laboratory hospitals of Aquitaine, have been collected and divided in susceptibility profiles. A total of 9269 strains (7323 enterobacteria, 1667 P. aeruginosa, 279 Acinetobacter) have been examined. On the whole, cefepime (91,5%) and ceftazidime (91,7%) were the most active cephalosporins, followed by cefpirome (87,9%) and cefotaxime (80,4%); imipenem was the most active beta-lactam agent (97,4%). When the strains were divided according to their susceptibility profiles, the advantage of cefepime was shown to be related to its excellent activity against enterobacteria: all strains susceptible to cefotaxime and ceftazidime (CTX/CAZ-S) were susceptible to cefepime, as were most of the strains with an intermediate susceptibility or resistant to these drugs (CTX/CAZ-I/R, approximately 5% of the enterobacteria). The latter strains exhibited a phenotype corresponding either to the overproduction of their chromosomal cephalosporinase (approximately 20% of the species belonging to group 3) or to the synthesis of an extended spectrum beta-lactamase (19% of the strains of Klebsiella pneumoniae). Cefepime was active against 93% of the derepressed mutants of enterobacteria, including 3 imipenem resistant isolates of Enterobacter. CAZ-S strains of P. aeruginosa (84%) were usually susceptible to cefepime (80%), as were 6% of the CAZ-I/R strains. CAZ-S strains of A. baumannii (16.3%) were generally susceptible to cefepime (83%), as were 3.2% of the CAZ-I/R strains.

Value of influenza vaccine during an outbreak of influenza A in a nursing home, Pyrenees Atlantiques, France, November-December 1995.

A public health officer of the Direction Departementale de l'Action Sanitaire et Sociale des Pyrenees Atlantiques in France was notified of an outbreak of acute respiratory illness among residents of a nursing home on 4 December, 1995. Over 50 of the 69 r