Frequency Of Maximum Intensity Research Articles

Wheezing Characteristics and Predicting Reactivity to Inhaled β2-Agonist in Children for Home Medical Care.

Background: Given that wheezing is treated with inhaled β2-agonists, their effect should be reviewed before the condition becomes severe; however, few methods can currently predict reactivity to inhaled β2-agonists. We investigated whether preinhalation wheezing characteristics identified by lung sound analysis can predict reactivity to inhaled β2-agonists.Methods: In 202 children aged 10–153 months, wheezing was identified by auscultation. Lung sounds were recorded for 30 s in the chest region on the chest wall during tidal breathing. We analyzed the wheezing before and after β2-agonist inhalation. Wheezing was displayed as horizontal bars of intensity defined as a wheeze power band, and the wheezing characteristics (number, frequency, and maximum intensity frequency) were evaluated by lung sound analysis. The participants were divided into two groups: non-disappears (wheezing did not disappear after inhalation) and disappears (wheezing disappeared after inhalation). Wheezing characteristics before β2-agonist inhalation were compared between the two groups.The characteristics of wheezing were not affected by body size. The number of wheeze power bands of the non-responder group was significantly higher than those of the responder group (P < 0.001). The number of wheeze power bands was a predictor of reactivity to inhaled β2-agonists, with a cutoff of 11.1. The 95% confidence intervals of sensitivity, specificity, and positive and negative predictive values were 88.8, 42, 44, and 81.1% (P < 0.001), respectively.Conclusions: The number of preinhalation wheeze power bands shown by lung sound analysis was a useful indicator before treatment. This indicator could be a beneficial index for managing wheezing in young children.

Datos para la fundamentación empírica de la escisión fonemática prestigiosa de /ts/

Fecha de recepción:­ 26 ­de­ agosto­ de­ 2009.Fecha de aceptación: ­17 ­de ­junio­ de ­2010. En el presente trabajo se analiza la relación existente entre la percepción de /s/ y /t/ del español y una serie de parámetros acústicos (duración delsegmento, frecuencia de inicio de la fricación, intensidad media, frecuencia de máxima intensidad, intensidad máxima y centro de gravedad) endos variedades del español hablado en la provincia de Málaga, 1) una variedad rural caracterizada por la indistinción del par de fricativas propio del español estándar y 2) una variedad urbana convergente en la dirección del estándar nacional, en la que se introduce la distinción. Los datos obtenidos indican que la intensidad tiene un importante papel tanto en la discriminación habitual de uno u otro sonido entre hablantes urbanos, como en las estrategias que emplean los hablantes rurales con un patrón de realización habitual reductor cuando prefieren articular el sonido no mate.

On the frequency modulation of VLF emissions

Abstract. The VLF-wave frequency modulation efficiency as a function of magnetosphere plasma parameters under the weak pitch-angle diffusion regime is studied. The study is based on the VLF growth-rate modulation both in the magnetosphere equatorial plane and after integrating along the magnetic field line. It is shown that for the typical quiet magnetosphere plasma parameters the relative shift of the maximum intensity frequency ∆ωm/ωm is approximately equal to relative disturbance of the magnetic field in the magnetosphere equatorial plane, but may exceed it when both electron temperature anisotropy and the parameter αβ∥are small; here α is the total-to-warm electron content ratio and β∥ is the electron parallel beta. It is also shown that relative shift of the maximum intensity frequency ∆ωm/ωm after integrating along the field line is not less than 50% from its value at the equatorial plane, which allows the use of the equatorial-plasma-parameter data to estimate the VLF frequency modulation on the ground. The upper cut-off frequency modulation is considered as well. The calculated theoretical sonagrams show that this frequency modulation may be related to the non-dispersive and to the "inverted-V'' structures of QP hiss.

Averaged and Time-Gated Spectral Analysis of Respiratory Sounds: Repeatability of Spectral Parameters in Healthy Men and in Patients With Fibrosing Alveolitis

To obtain a basis for assessment of changes in breath sound spectra in patients with pulmonary diseases, short-term and day-to-day repeatability of spectral parameters was studied. Breath sounds were recorded simultaneously from the trachea and from the chest twice at an interval of 15 min (short-term repeatability) and of 1 to 3 days (day-to-day repeatability). During recordings, air flow at the mouth was controlled, the target inspiratory and expiratory peak flow being 1.25 L/s. Inspiratory and expiratory breath sound spectra were averaged over 7 to 10 successive respiratory cycles. The repeatability of sound intensity (RMS), frequency of maximum intensity (Fmax), and median frequency (F50) was analyzed with analysis of variance. Short-term repeatability was studied in 10 healthy nonsmoking men (age 25 to 44 years), and day-to-day repeatability was studied in 10 healthy nonsmoking men (age 23 to 41 years) and in 12 patients with clinically stable fibrosing alveolitis (age 35 to 82 years). Short-term coefficient of variation (CoV) of Fmax and F50 was 2.6 to 6.7% when recorded from the chest, and 6.2 to 8.7% when recorded from the trachea. Day-to-day CoV of Fmax and F50 in healthy subjects was 4.7 to 8.5% and 5.0 to 8.7% recorded from the chest or from the trachea, respectively. Inspiratory day-to-day variation in those parameters was higher in patients with fibrosing alveolitis. CoV of RMS was high, ranging from 18 to 47% in different subject groups and sampling situations. Repeatability of F50 of averaged flow-controlled lung sound spectra is good both in healthy subjects and in patients with fibrosing alveolitis. Thus, F50 of respiratory sound spectra may be useful in monitoring of changes induced by respiratory diseases and interventions. These results emphasize the importance of standardization of recording conditions and of analyzing techniques.

Fast determination of the quantitative secondary structure of proteins by using some parameters of the Raman Amide I band

A very simple and fast method is presented for the quantitative determination of the secondary structural contents of a protein by Raman spectroscopy. We performed a statistical analysis of the correlations between the structural data on the one hand, obtained from X-ray crystallography, and the spectroscopic Raman data on the other, this has been for a large set of reference proteins. Such multi-parametric analysis permits one to express the percentages of structural contents of a protein in terms of some simple parameters of the experimental Raman Amide I band of that protein (maximum intensity frequency, width …). For instance, in a single parameter analysis, it was shown that the secondary structures can be estimated with accuracy from the knowledge of only the frequency of the peak of the Raman Amide I band. This, by using equations of the type: % structure = a ν(maximum) + b. a and b are coefficients calculated for each class of structure by using the least squares method. The best agreement between observed and calculated structures is obtained when using as parameters the frequency of the peak and both the left and right half band widths of the Amide I band.

Observatioas of the Spectrum of High-Intensity Solar Radiation at Metre Wavelengths. I. The Apparatus and Spectral Types of Solar Burst Observed

An apparatus for recording the dynamic spectrum of high-intensity solar radiation (in particular the sudden bursts) in the frequency range 70-130 Mc/s. is described. The spectra are displayed on a cathode-ray tube at intervals of about one-third of a second. �� Solar bursts observed with the apparatus were found to have widely different spectra. However, analysis of a number of bursts indicated the common occurrence of three distinct spectral types. These types are described and illustrated by samples. One type, of narrow bandwidth, was exhibited by short-lived bursts that occur in large numbers during periods of high intensity ( ?noise storms?) ; these bursts are presumed to be circularly polarized and associated with sunspots. A second type, characterized by a slow drift of spectral features towards the lower frequencies, was exhibited by sporadic " outbursts " associated with solar flares. Other sporadic bursts had diverse spectra, but some of them conformed to a third spectral type in which the frequency of maximum intensity drifts rapidly towards the lower frequencies. �� The result that outbursts seem to exhibit a distinct type of spectrum is considered to provide a possible means of recognizing these phenomena with certainty.