A target guided subband filter for acoustic event detection in noisy environments using wavelet packets

This paper deals with acoustic event detection (AED), such as screams, gunshots, and explosions, in noisy environments. The main aim is to improve the detection performance under adverse conditions with a very low signal-to-noise ratio (SNR). A novel filtering method combined with an energy detector is presented. The wavelet packet transform (WPT) is first used for time-frequency representation of the acoustic signals. The proposed filter in the wavelet packet domain then uses a priori knowledge of the target event and an estimate of noise features to selectively suppress the background noise. It is in fact a content-aware band-pass filter which can automatically pass the frequency bands that are more significant in the target than in the noise. Theoretical analysis shows that the proposed filtering method is capable of enhancing the target content while suppressing the background noise for signals with a low SNR. A condition to increase the probability of correct detection is also obtained. Experiments have been carried out on a large dataset of acoustic events that are contaminated by different types of environmental noise and white noise with varying SNRs. Results show that the proposed method is more robust and better adapted to noise than ordinary energy detectors, and it can work even with an SNR as low as -15 dB. A practical system for real time processing and multi-target detection is also proposed in this work

Generic and oral quality of life is affected by oral mucosal diseases

<p>Abstract</p> <p>Background</p> <p>The generic and oral health-related quality of life (QoL) has provided opportunity for investigation of the interrelations among generic health, oral health, and related outcomes. The purpose of this study was to identify the generic and oral QoL in the patients with oral mucosal disease (OMD).</p> <p>Methods</p> <p>Five hundred and thirty-eight OMDs were recruited in this study. The instruments applied were Chinese version of the 36-item short form health survey (SF-36) and the short-form of Oral Health Impact Profile (OHIP-14).</p> <p>Results</p> <p>The mean score of sum OHIP-14 was significantly higher in the patients with OMD (10.81 ± 9.01) compared with those in the healthy subjects (HS) (6.55 ± 6.73) (p < 0.001, Mann-Whitney U test). 56.51% of the OMD patients and 12.94% of the HS reported at least one oral negative impact (p < 0.001, Chi-square test). The overall mean score of SF-36 was significantly lower in the patients with OMD (74.54 ± 12.77) compared with those in the HS (77.97 ± 12.39) (p = 0.021, t-test).</p> <p>Conclusions</p> <p>Administration of specific and generic questionnaires of QoL can provide us a detailed picture of the impact of OMDs on patients, and both generic and oral QoL were impaired in the patients with OMD.</p

Total Nuclear Reaction Cross Section Induced by Halo Nuclei and Stable Nuclei

We develop the method for the calculation of the total reaction cross sections induced by the halo nuclei and stable nuclei. This approach is based on the Glauber theory, which is valid for nuclear reactions at high energy. It is extended for nuclear reactions at low energy and intermediate energy by including both the quantum correction and Coulomb correction under the assumption of the effective nuclear density distribution. The calculated results of the total reaction cross section induced by stable nuclei agree well with the 30 experimental data within 10 percent accuracy.The comparison between the numerical results and the 20 experimental data for the total nuclear reaction cross section induced by the neutron halo nuclei and the proton halo nuclei indicates a satisfactory agreement after considering the halo structure of these nuclei, which implies the quite different mean fields for the nuclear reactions induced by halo nuclei and stable nuclei. The halo nucleon distributions and the root mean square radii of these nuclei can be extracted from above comparison based on the improved Glauber model, which indicate clearly the halo structures of these nuclei. Especially, it is clear to see that the medium correction of the nucleon-nucleon collision has little effect on the total reaction cross sections induced by the halo nuclei due to the very weak binding and the very extended density distribution.Comment: 15 pages,2 figures. Communucations in Theoretical Physics, (2003) in pres

\u3ci\u3eIn Vitro\u3c/i\u3e Stable Isotope Labeling for Discovery of Novel Metabolites by Liquid Chromatography-Mass Spectrometry: Confirmation of γ-Tocopherol Metabolism in Human A549 Cell

A general approach for discovering novel catabolic metabolites from a parent biocompound was developed and validated on metabolism of γ-tocopherol in human A549 cell. Method is based on LC-MS analysis of in vitro stable isotope labeled metabolites and assumes that a parent compound and its metabolites share a common functional group that can be derivatized by well-documented reagents. In this method, two equal aliquots of extracted metabolites are separately derivatized with isotope-coded (heavy) and non-isotope-coded (light) form of derivatizing reagent, mixed at 1:1 ratio and analyzed using LC-MS. The metabolites with common functional group are then easily recognized by determination of a chromatographically co-eluted pair of isotopomers (MS doublet peaks) with similar peak intensities and mass difference corresponding to the mass difference between heavy and light form of derivatization reagent. The feasibility of this approach was demonstrated and validated by identification of products of γ-tocopherol catabolism in human A549 cell culture media using N-methyl-nicotinic acid N-hydroxysuccinimide ester (C1-NANHS) and Nmethyl- d3-nicotinic acid N-hydroxysuccinimide ester (C1-d3-NANHS) derivatizing reagent. Overall four γ-tocopherol metabolites were identified including 9\u27-COOH, 11\u27-COOH, 13\u27-COOH and 13\u27-OH. In addition, the developed LC-MS method can also be used for the fast and sensitive quantitative analysis of γ-tocopherol and other forms of vitamin E related compounds

Effects of typhoons on gelatinous carnivore zooplankton off Northern Taiwan

We examine the effect of typhoons, as potential drivers of nutrient pulse events, on gelatinous carnivore zooplankton. The period investigated spanned from 2007 to 2010, where seasonal abundance and taxonomic composition of the gelatinous zooplankton community was recorded off North Taiwan. Typhoon effects were assessed in the abundance, diversity and species richness of the gelatinous carnivore populations. Significant associations between typhoons and gelatinous carnivores were found in time delays varying from 3 to 25 days, but no association was identified for longer time intervals. Generally, a decrease in species richness occurred during the summer season, and this was accentuated in 2008, shortly after typhoons events. We hypothesize that typhoons might act as resource pulse triggers probably enhancing open niches for opportunistic carnivore zooplankton groups

Poly[[tetra­aqua­di-μ4-oxalato-μ2-oxalato-dineo­dymium(III)] dihydrate]

The title compound, {[Nd2(C2O4)3(H2O)4]·2H2O}n, was synthesized hydro­thermally in the presence of bis­(carb­oxy­ethyl­germanium) sesquioxide. It is isostructural with the corresponding Pr compound [Yang et al. (2009). Acta Cryst. E65, m1152–m1153]. The Nd3+ cation is nine-coordinated and its coordination polyhedron can be described as a distorted tricapped trigonal prism. Two Nd3+ ions are connected by two O atoms from two oxalate ions to give a dinuclear Nd2 unit. The unit is further linked to four others via four oxalate ions yielding a layerparallel to (0-11). The linkages between the layers by neighbouring oxalate anions lead to a three-dimensional framework with channels along the c axis. The coordinating and free water mol­ecules are located in the channels and make contact with each other and the host framework by weak O—H⋯O hydrogen bonds