The continuous development of urbanization has dramatically changed people’s living environment and lifestyle, accompanied by the increased prevalence of chronic diseases. However, there is little research on the effect of urbanization on gut microbiome in residents. Here we investigated the relation between living environment and gut microbiota in a homogenous population along an urban-rural gradient in Ningxia China. According to the degree of urbanization, the population is divided into four groups: mountainous rural (MR) represents non-urbanized areas, mountainous urban (MU) and plain rural (PR) represent preliminary urbanization, and plain urban (PU) is a representative of complete urbanization. Studies have found that with the deepening of urbanization, the prevalence of chronic diseases, such as diabetes, dyslipidemia, fatty liver, gallstones, and renal cysts, have gradually increased. The intestinal richness and diversity of the microbial community were significantly reduced in the PR and the PU groups compared with the MR and the MU groups. Based on linear discriminant analysis selection, the significantly enriched genera Faecalibacterium, Prevotella, and Pseudobutyrivibrio in the MR group gradually decreased in the MU, the PR, and the PU groups. Effect size results revealed that both residence and diet had an effect on intestinal microbiota. Our results suggested that the disparate patterns of gut microbiota composition were revealed at different levels of urbanization, providing an opportunity to understand the pathogenesis of chronic diseases and the contribution of the “rural microbiome” in potential protection against the occurrence of chronic diseases.

Pharmaceutical product development culminates in confirmatory trials whose evidence for the product's efficacy and safety supports regulatory approval for marketing. Regulatory agencies in countries whose patients were not included in the confirmatory trials often require confirmation of efficacy and safety in their patient populations, which may be accomplished by carrying out bridging studies to establish consistency for local patients of the effects demonstrated by the original trials. This article describes and illustrates an approach for designing and analyzing bridging studies that fully incorporates the information provided by the original trials. The approach determines probability contours or regions of joint predictive intervals for treatment effect and response variability, or endpoints of treatment effect confidence intervals, that are functions of the findings from the original trials, the sample sizes for the bridging studies, and possible deviations from complete consistency with the original trials. The bridging studies are judged consistent with the original trials if their findings fall within the probability contours or regions. Regulatory considerations determine the region definitions and appropriate probability levels. Producer and consumer risks provide a way to assess alternative region and probability choices. [Supplemental materials are available for this article. Go to the Publisher's online edition of the Journal of Biopharmaceutical Statistics for the following free supplemental resource: Appendix 2: R code for Calculations.].

No abstract

In this paper, trajectory tracking control is investigated for lower extremity rehabilitation exoskeleton robot. Unknown perturbations are considered in the system which are inevitable in the reality. The trajectory tracking control is constructively treated as constrained control issue. To obtain the explicit equation of motion and analytical solution of lower extremity rehabilitation exoskeleton robot, Udwadia-Kalaba theory is introduced. Lagrange multipliers and pseudo variables are not needed in Udwadia-Kalaba theory, which is more superior than Lagrange method. On the basic of Udwadia-Kalaba theory, two constrained control methods including trajectory stabilization control and adaptive robust control are proposed. Trajectory stabilization control applies Lyapunov stability theory to modify the desired trajectory constraint equations. A leakage-type of adaptive law is designed to compensate unknown perturbations in adaptive robust control. Finally, comparing with nominal control and control method in [32], simulation results demonstrate the superiority of trajectory stabilization control and adaptive robust control in trajectory tracking control.

In this study, the fatigue damage modes of carbon fiber/epoxy composite laminates with symmetrical architecture were investigated by acoustic emission (AE) technique under fully reversed loading. The principal component analysis and the K‐means cluster analysis using correlation AE characteristic parameters, including the energy, the amplitude, and the duration time, were performed to identify various damage modes during the fatigue test process. The analysis results of the AE signals indicated that the high‐intensity AE signals were generated by the compressive load and the low‐intensity AE signals were generated by the tensile load. The maximum energy and duration time generated by the compression load are approximately 20 and 10 times that of the tensile load, respectively, which was consistent with the force‐controlled static test results under tension and compression loadings. Therefore, the fatigue damage caused by the compressive load is much greater than that of tensile load under fully reversed loading. The results of the multi‐AE parametric clustering analysis combined with scanning electron microscope micromorphology revealed that the damage modes of the laminate specimens were classified into five types, namely matrix cracks, fiber/epoxy interface debonding, shear, delamination, and fiber breakage. In addition, the damage modes at different stages during the fatigue test process were also analyzed and discussed.