On well-posedness of forward-backward SDEs-A unified approach

In this paper, we study the well-posedness of the Forward-Backward Stochastic Differential Equations (FBSDE) in a general non-Markovian framework. The main purpose is to find a unified scheme which combines all existing methodology in the literature, and to address some fundamental longstanding problems for non-Markovian FBSDEs. An important device is a decoupling random field that is regular (uniformly Lipschitz in its spatial variable). We show that the regulariy of such decoupling field is closely related to the bounded solution to an associated characteristic BSDE, a backward stochastic Riccati-type equation with superlinear growth in both components $Y$ and $Z$. We establish various sufficient conditions for the well-posedness of an ODE that dominates the characteristic BSDE, which leads to the existence of the desired regular decoupling random field, whence the solvability of the original FBSDE. A synthetic analysis of the solvability is given, as a "User's Guide," for a large class of FBSDEs that are not covered by the existing methods. Some of them have important implications in applications.Comment: Published at http://dx.doi.org/10.1214/14-AAP1046 in the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org

Numerical modeling of pile penetration in silica sands considering the effect of grain breakage

International audienceCurrent numerical platforms rarely consider the effect of grain breakage in the design of sandy soil foundations. This paper presents an enhanced platform for large deformation analyses which considers the effect of grain breakage during pile penetration in silica sand. For this purpose, a model based on critical state theory has been developed within the framework of multisurface plasticity to account in the same constitutive platform the effect of stress dilatancy and particle fragmentation. Furthermore, to implement the underlying constitutive equations into a finite element code, a stress integration scheme has been adopted by extending a cutting plane algorithm to the model with multiple yielding mechanisms. A laboratory model test and a series of centrifuge tests of pile penetration are simulated to verify the performance of the selected constitutive approach in terms of pile resistance and grain breakage distribution, with the parameters of sand calibrated through a set of drained triaxial compression tests from low to very high confining pressure. Some extra features of the enhanced platform are also discussed, such as: i) the effect of sand crushability on pile resistance and ii) the nonlinear relation of pile resistance to sand density. The proposed findings demonstrate the capability of this numerical platform to proper design of pile foundation in sandy soils and highlight the interplay between stress dilatancy and grain breakage mechanisms during pile penetration processes

Psychological Stress Induces Temporary Masticatory Muscle Mechanical Sensitivity in Rats

To explore the relationship between psychological stress and masticatory muscle pain, we created a communication stress animal model to determine whether psychological stress could induce increased mechanical sensitivity in masticatory muscles and to study the changes of mechanical nociceptive thresholds after stress removal. Forty-eight male Sprague-Dawley rats were divided into a control group (CON), a foot-shocked group (FS, including 3 subgroups recorded as FS-1, FS-2, and FS-3), a psychological stress group (PS), and a drug treatment group (DT). PS and DT rats were confined in a communication box for one hour a day to observe the psychological responses of neighboring FS rats.Measurements of the mechanical nociceptive thresholds of the bilateral temporal and masseter muscles showed a stimulus-response relationship between psychological stress and muscle mechanical sensitivity. The DT rats, who received a diazepam injection, showed almost the same mechanical sensitivity of the masticatory muscles to that of the control in response to psychological stress. Fourteen days after the psychological stressor was removed, the mechanical nociceptive thresholds returned to normal. These findings suggest that psychological stress is directly related to masticatory muscle pain. Removal of the stressor could be a useful method for relieving mechanical sensitivity increase induced by psychological stress

To investigate the reasons and nursing strategies of postoperative return to ICU in patients with severe valvular disease

目的  探讨重症瓣膜置换病人术后再次非计划性返回ICU的重返率及原因。根据原因分析建立最佳护理模式及干预策略，通过护理干预手段降低重返率，提高治愈率及患者术后康复质量。方法  回顾性分析2010年6月—2015年6月间150例重症瓣膜置患者术后重返ICU患者的临床资料、分析重返的原因。结果  150例重症瓣膜置换患者术后非计划重返ICU的患者有17例，重返率为11.3%。重返的主要原因是呼吸困难、恶性心律失常、低心排、循环负荷过重、家属照护压力大主动要求重返ICU等。结论  制定合理的转出标准；合理配置人力资源，动态监测，密切观察患者生命体征、出入量平衡、电解质平衡；提供个性化健康指导提高患者及家属的遵医行为是降低ICU重返率的有效措施。Objective: To investigate the return rate and causes of postoperative non - planned return to ICU in patients with severe valve replacement. According to the analysis of the reasons, establish the best nursing model and intervention strategies, through the nursing intervention to reduce the return rate, and improve the cure rate and postoperative rehabilitation quality. Methods: Retrospective analysis of clinical data of 150 cases of severe valvular replacement patients who returned to ICU in June, June 2010, and the reasons for the return of ~2015. Results: 150 cases of patients with severe heart valve replacement patients, among them 150 cases had no plan to return to ICU, the return rate was 11.3%. The main reason to return to ICU is the difficulty of breathing, malignant arrhythmia, low cardiac output, overweight, family care pressure and so on n. Conclusion: To establish a reasonable standard of transfer; the rational allocation of human resources, dynamic monitoring, close observation of vital signs of patients, access to balance, electrolyte balance; providing personalized health guidance to improve the compliance behavior of patients and their families are the effective measures to reduce the ICU readmission rate.