Digital processing of speech signals

: This thesis applies neural network feature selection techniques to multivariate time series data to improve prediction of a target time series. Two approaches to feature selection are used. First, a subset enumeration method is used to determine which financial indicators are most useful for aiding in prediction of the S&P 500 futures daily price. The candidate indicators evaluated include RSI, Stochastics and several moving averages. Results indicate that the Stochastics and RSI indicators result in better prediction results than the moving averages. The second approach to feature selection is calculation of individual saliency metrics. A new decision boundary-based individual saliency metric, and a classifier independent saliency metric are developed and tested. Ruck's saliency metric, the decision boundary based saliency metric, and the classifier independent saliency metric are compared for a data set consisting of the RSI and Stochastics indicators as well as delayed closing price values. The decision based metric and the Ruck metric results are similar, but the classifier independent metric agrees with neither of the other metrics. The nine most salient features, determined by the decision boundary based metric, are used to train a neural network and the results are presented and compared to other published results. (AN)

/pdf/nonlinear-time-series-analysis-1j3a35n4y3.pdf

Nonlinear Time Series Analysis.

Neural networks

Dentin organic matrix, with type I collagen as the main component, is exposed after demineralization in dentinal caries, erosion or acidic conditioning during adhesive composite restorative treatment. This exposed matrix is prone to slow hydrolytic degradation by host collagenolytic enzymes, matrix metalloproteinases (MMPs) and cysteine cathepsins. Here we review the recent findings demonstrating that inhibition of salivary or dentin endogenous collagenolytic enzymes may provide preventive means against progression of caries or erosion, just as they have been shown to retain the integrity and improve the longevity of resin composite filling bonding to dentin. This paper also presents the case that the organic matrix in caries-affected dentin may not be preserved as intact as previously considered. In partially demineralized dentin, MMPs and cysteine cathepsins with the ability to cleave off the terminal non-helical ends of collagen molecules (telopeptides) may lead to the gradual loss of intramolecular gap areas. This would seriously compromise the matrix ability for intrafibrillar remineralization, which is considered essential in restoring the dentin's mechanical properties. More detailed data of the enzymes responsible and their detailed function in dentin-destructive conditions may not only help to find new and better preventive means, but better preservation of demineralized dentin collagenous matrix may also facilitate true biological remineralization for the better restoration of tooth structural and mechanical integrity and mechanical properties.

/pdf/matrix-metalloproteinases-and-other-matrix-proteinases-in-3xaor2t706.pdf

Matrix Metalloproteinases and Other Matrix Proteinases in Relation to Cariology: The Era of ‘Dentin Degradomics'

Optimizing dentin bond durability: Control of collagen degradation by matrix metalloproteinases and cysteine cathepsins

Wavelet time-frequency analysis and least squares support vector machines for the identification of voice disorders

This proof-of-concept study assessed whether the reduction of the degradation of the demineralized organic matrix (DOM) by pre-treatment with protease inhibitors (PI) is effective against dentin matrix loss. Bovine dentin slices were demineralized with 0.87 M citric acid, pH 2.3, for 36 hrs. In sequence, specimens were treated or not (UT, untreated) for 1 min with gels containing epigallocatechin 3-gallate (EGCG, 400 µM), chlorhexidine (CHX, 0.012%), FeSO4 (1 mM), NaF (1.23%), or no active compound (P, placebo). Specimens were then stored in artificial saliva (5 days, 37°C) with the addition of collagenase (Clostridium histolyticum, 100 U/mL). We analyzed collagen degradation by assaying hydroxyproline (HYP) in the incubation solutions (n = 5) and evaluated the dentin matrix loss by profilometry (n = 12). Data were analyzed by ANOVA and Tukey’s test (p < 0.05). Treatment with gels containing EGCG, CHX, or FeSO4 led to significantly lower HYP concentrations in solution and dentin matrix loss when compared ...

https://journals.sagepub.com/doi/pdf/10.1177/0022034512455801

Impact of Protease Inhibitors on Dentin Matrix Degradation by Collagenase

Introduction: Acoustic analysis of the voice with advance of the digital technology increases as a promising complementary exam for raising the diagnostic precision in laringology. Aim: Standardization of the acoustic measurement of fundamental frequency, Perturbations and noise in the normal voice of male and female brazilians. Study design: Clinical prospective. Material and method: Research was carried out from March to August of 1997 in the Otorlaryngological Clinic of the Clinical Hospital of the Faculty of Medicine of Ribeirao Preto of the University of Sao Paulo, using 80 volunteers of the city of Ribeirao Preto and its region, consisting of 40 males and 40 females, and selected by means of a triage. Digital recordings of the vowels /a/, /e/, and /i/ were utilized, originating in a sample of 240 acoustic signals, and submitted to the Program of Acoustic Voice Analysis, with the Sao Carlos School of Engineering of the University of Sao Paulo securing the acoustic measurements. Results: Mean values in relationship to sex and phonemes were obtained in the measurements of: Fundamental Frequency, Jitter (Directional Perturbation Factor, Perturbation Variation Index, Jitter Ratio, Jitter Factor, Period Perturbation Quotient), Shimmer (Directional Perturbation Factor, Amplitude Variation Index, Amplitude Perturbation Quotient), Spectral Noise Level, Harmonic-to-noise ratio, Harmonic-to-noise ratio cepstrum, Normalized Noise Energy e Breathiness ratio. Conclusion: The normalization of acoustic measurements is necessary to better know the normal voice. The great majority of obtained values are compatible with existing literature.

/pdf/normatizacao-de-medidas-acusticas-da-voz-normal-2nnskol85i.pdf

Normatização de medidas acústicas da voz normal

Properties of dental resins submitted to pH catalysed hydrolysis

It is known that some metal salts can inhibit matrix metalloproteinase (MMP) activity, but the effect of iron has not been tested yet. On the other hand, it has recently been suggested that MMP inhibition might influence dentine erosion. Based on this, the aims of this study were: (1) to test in vitro the effect of FeSO4 on MMP-2 and -9 activity, and (2) to evaluate in situ the effect of FeSO4 gel on dentine erosion. MMP-2 and -9 activities were analysed zymographically in buffers containing FeSO4 in concentrations ranging between 0.05 and 1.5 mmol/l or not. Volunteers (n = 10) wore devices containing bovine dentine blocks (n = 60) previously treated with the following gel treatments: FeSO4 (1 mmol/l FeSO4), F (NaF 1.23%; positive control) and placebo (negative control). The gels were applied once and removed after 1 min. Erosion was performed extraorally with Coca-Cola 4 times per day for 5 min over 5 days. Dentine wear was evaluated by profilometry. The data were analysed by Kruskal-Wallis and Dunn’s tests (p 4 inhibited both MMP-2 (IC50 = 0.75 mmol/l) and MMP-9 (IC50 = 0.50 mmol/l) activities. In the in situexperiment, the mean wear (± SD) found for the F gel (0.79 ± 0.08 µm) was significantly reduced in more than 50% when compared to the placebo gel (1.77 ± 0.33 µm), but the FeSO4 gel completely inhibited the wear (0.05 ± 0.02 µm). Since FeSO4 was able to inhibit MMP in vitro, it is possible that the prevention of dentine wear by the FeSO4 gel in situ might be due to MMP inhibition, which should be investigated in further studies.

José Carlos Pereira

Papers

Wavelet time-frequency analysis and least squares support vector machines for the identification of voice disorders

Impact of Protease Inhibitors on Dentin Matrix Degradation by Collagenase

Normatização de medidas acústicas da voz normal

Properties of dental resins submitted to pH catalysed hydrolysis

Effect of iron on matrix metalloproteinase inhibition and on the prevention of dentine erosion.