Analysis of Structural Health Monitoring Data with Correlated Measurement Error by Bayesian System Identification: Theory and Application.

Measurement error is non-negligible and crucial in SHM data analysis. In many applications of SHM, measurement errors are statistically correlated in space and/or in time for data from sensor networks. Existing works solely consider spatial correlation for measurement error. When both spatial and temporal correlation are considered simultaneously, the existing works collapse, as they do not possess a suitable form describing spatially and temporally correlated measurement error. In order to tackle this burden, this paper generalizes the form of correlated measurement error from spatial correlation only or temporal correlation only to spatial-temporal correlation. A new form of spatial-temporal correlation and the corresponding likelihood function are proposed, and multiple candidate model classes for the measurement error are constructed, including no correlation, spatial correlation, temporal correlation, and the proposed spatial-temporal correlation. Bayesian system identification is conducted to achieve not only the posterior probability density function (PDF) for the model parameters, but also the posterior probability of each candidate model class for selecting the most suitable/plausible model class for the measurement error. Examples are presented with applications to model updating and modal frequency prediction under varying environmental conditions, ensuring the necessity of considering correlated measurement error and the capability of the proposed Bayesian system identification in the uncertainty quantification at the parameter and model levels.

The development, validity, reliability, and norm of a preschool auditory processing assessment scale in China.

BACKGROUND: Children with auditory processing deficits may face problems with language, learning, and social communication. AIMS: To develop a Chinese auditory processing assessment scale for preschool children and establish the norms of the scale. METHODS AND PROCEDURES: The predictive version of the scale was formed by a literature review, qualitative interviews, expert consultation, and a pre-test with a small sample. Nine kindergartens in Nanjing were selected by a stratified cluster sampling plan. First, 734 children from two kindergartens were selected for the large sample pre-test of the scale. Then, 1526 children from four kindergartens and 1151 children from three kindergartens were selected for the reliability and validity analysis and confirmatory factor analysis, respectively. The standardized norm data of the scale were established based on the 3411 points of scale data of the nine kindergartens. Finally, the clinical usefulness of the scale was analyzed by comparing the results of objective auditory processing tests in children with normal and abnormal auditory processing prompted by the score on the scale. OUTCOMES AND RESULTS: The preschool auditory processing assessment scale includes 5 dimensions and 30 items. The Cronbach's alpha value of the scale is greater than 0.9. The confirmatory factor analysis results verify that the scale structure is reasonable. The percentile norm of the scale was established. The results of electrophysiological tests of the normal and abnormal auditory processing groups were statistically different (P < 0.05). CONCLUSIONS AND IMPLICATIONS: The developed preschool auditory processing assessment scale has good reliability and validity. The scale is suitable for clinical application.

Copula-Based Uncertainty Quantification (Copula-UQ) for Multi-Sensor Data in Structural Health Monitoring.

The problem of uncertainty quantification (UQ) for multi-sensor data is one of the main concerns in structural health monitoring (SHM). One important task is multivariate joint probability density function (PDF) modelling. Copula-based statistical inference has attracted significant attention due to the fact that it decouples inferences on the univariate marginal PDF of each random variable and the statistical dependence structure (called copula) among the random variables. This paper proposes the Copula-UQ, composing multivariate joint PDF modelling, inference on model class selection and parameter identification, and probabilistic prediction using incomplete information, for multi-sensor data measured from a SHM system. Multivariate joint PDF is modeled based on the univariate marginal PDFs and the copula. Inference is made by combing the idea of the inference functions for margins and the maximum likelihood estimate. Prediction on the PDF of the target variable, using the complete (from normal sensors) or incomplete information (due to missing data caused by sensor fault issue) of the predictor variable, are made based on the multivariate joint PDF. One example using simulated data and one example using temperature data of a multi-sensor of a monitored bridge are presented to illustrate the capability of the Copula-UQ in joint PDF modelling and target variable prediction.

Meranzin hydrate exhibits anti-depressive and prokinetic-like effects through regulation of the shared α2-adrenoceptor in the brain-gut axis of rats in the forced swimming test.

BACKGROUND: In recent years, the brain-gut axis theory has received increasing attention in studies of depression. However, most studies separately address potential antidepressant and prokinetic treatments. Investigations of drugs that could potentially treat comorbid depression and gastrointestinal (GI) dysfunction via a common mechanism of action have not yet been performed in detail. AIM: To find a common mechanism of action of our patented drug, meranzin hydrate (MH), in the antidepressant and prokinetic treatment. METHODS: The forced swimming test (FST) model of depression, plasma ghrelin measurement, and in vivo and in vitro measurements of GI motility were used. RESULTS: 1. Administration of MH (9 mg/kg) decreased the immobility time during the FST after acute treatment; this effect was inhibited by the alpha 2-adrenoceptor antagonist, yohimbine, but not by the alpha 1-adrenoceptor antagonist, prazosin. 2. After chronic treatment, the immobility time of rats during the FST was decreased significantly by MH (2.25 mg/kg). 3. MH (9 mg/kg) increased plasma ghrelin levels in rats subjected to the FST; this increase was enhanced by the ghrelin receptor agonist, GHRP-6. 4. MH (9 mg/kg) also promoted gastric emptying and intestinal transit in rats with or without FST. 5. In vitro, MH (10 µM) increased jejunal contractions in rats subjected to the FST; this effect was inhibited by yohimbine. Furthermore, the inhibitory effect of yohimbine was partly reversed by the ghrelin receptor agonist, GHRP-6. CONCLUSION: Our study revealed that MH from natural resources exhibits antidepressive and prokinetic-like effects through the regulation of the common mediator, the alpha 2-adrenoceptor.

Assessment of antidiabetogenic potential of fermented soybean extracts in streptozotocin-induced diabetic rat.

Most of the available drugs for the treatment of diabetes mellitus (DM) produce detrimental side effects, which has prompted an ongoing search for plant with the antidiabetic potential. The present study investigated the effect of soybean extracts fermented with Bacillus subtilis MORI, fermented soybean extracts (BTD-1) was investigated in streptozotocin (STZ)-induced diabetic rats. The possible effects of BTD-1 against hyperglycemia and free radical-mediated oxidative stress was investigated by assaying the plasma glucose level and the activity of enzymatic antioxidants, such as superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and malondialdehyde (MDA). A significant increase in the levels of both plasma glucose and reactive oxygen species (ROS) was observed in the diabetic rats when compared to normal control group. After administration of BTD-1 (500 and 1000 mg/kg/day), the elevated plasma glucose level was significantly reduced while the plasma insulin level and the activities of SOD, GSH-Px, CAT and MDA were significantly increased. The results suggest that administration of BTD-1 can inhibit hyperglycemia and free radical-mediated oxidative stress. The administration of BTD-1 also inhibited the contractile response by norepinephrine (10(-10)-10(-5) M) in the presence of endothelium, and caused significant relaxation by carbachol (10(-8)-10(-5) M) in rat aorta. These findings indicate that BTD-1 improves vascular functions on STZ-induced diabetic rats. Therefore, subchronic administration of BTD-1 could prevent the functional changes in vascular reactivity in STZ-induced diabetic rats. The collective findings support that administration of BTD-1 may prevent some diabetes-related changes in vascular reactivity directly and/or indirectly due to its hypoglycaemic effect and inhibition of production of ROS.

Assessment of UDP-glucuronosyltransferase catalyzed formation of Picroside II glucuronide in microsomes of different species and recombinant UGTs.

This study compared the hepatic glucuronidation of Picroside II in different species and characterized the glucuronidation activities of human intestinal microsomes (HIMs) and recombinant human UDP-glucuronosyltransferases (UGTs) for Picroside II. The rank order of hepatic microsomal glucuronidation activity of Picroside II was rat > mouse > human > dog. The intrinsic clearance of Picroside II hepatic glucuronidation in rat, mouse and dog was about 10.6-, 6.0- and 2.3-fold of that in human, respectively. Among the 12 recombinant human UGTs, UGT1A7, UGT1A8, UGT1A9 and UGT1A10 catalyzed the glucuronidation. UGT1A10, which are expressed in extrahepatic tissues, showed the highest activity of Picroside II glucuronidation (K(m) = 45.1 µM, V(max) = 831.9 pmol/min/mg protein). UGT1A9 played a primary role in glucuronidation in human liver microsomes (HLM; K(m) = 81.3 µM, V(max) = 242.2 pmol/min/mg protein). In addition, both mycophenolic acid (substrate of UGT1A9) and emodin (substrate of UGT1A8 and UGT1A10) could inhibit the glucuronidation of Picroside II with the half maximal inhibitory concentration (IC(50)) values of 173.6 and 76.2 µM, respectively. Enzyme kinetics was also performed in HIMs. The K(m) value of Picroside II glucuronidation was close to that in recombinant human UGT1A10 (K(m) = 58.6 µM, V(max) = 721.4 pmol/min/mg protein). The intrinsic clearance was 5.4-fold of HLMs. Intestinal UGT enzymes play an important role in Picroside II glucuronidation in human.