Adaptive distributed synchronization of heterogeneous multi-Agent systems over directed graphs with time-Varying edge weights

Time-varying edge weights represent dynamical interactions between any two nodes in multi-agent systems (MASs). In this paper, we consider a synchronization problem for heterogeneous MASs over directed graphs with time-varying edge weights from a control-theoretic perspective. We seek for an adaptive control protocol that drives the synchronization error in the presence of time-varying edge weights to converge in terms of asymptotic stability. We propose a class of observer networks for estimating leaders and output regulation equation solvers built on directed graphs with time-varying edge weights. Finally, we use a simulation study to verify the effectiveness of the proposed protocol.     

Sternal Precautions: Is It Time for Change? Precautions versus Restrictions – A Review of Literature and Recommendations for Revision

The processes that occur with normal sternal healing and potential complications related to median sternotomy are of particular interest to physical therapists. The premise of patients following sternal precautions (SP) or specific activity restrictions is the belief that avoiding certain movements will reduce risk of sternal complications. However, current research has identified that many patients remain functionally impaired long after cardiothoracic surgery. It is possible that some SP may contribute to such functional impairments. Currently, SP have several limitations including that they: (1) have no universally accepted definition, (2) are often based on anecdotal/expert opinion or at best supported by indirect evidence, (3) are mostly applied uniformly for all patients without regard to individual differences, and (4) may be overly restrictive and therefore impede ideal recovery. The purpose of this article is to present an overview of current research and commentary on median sternotomy procedures and activity restrictions. We propose that the optimal degree and duration of SP should be based on an individual patient''s characteristics (eg, risk factors, comorbidities, previous activity level) that would enable physical activity to be targeted to particular limitations rather than restricting specific functional tasks and physical activity. Such patient-specific SP focusing on function may be more likely to facilitate recovery after median sternotomy and less likely to impede it.Key Words: median sternotomy, sternal precautions, physical therapy, exercise protocols     

The influence of childhood maltreatment on adolescents' academic performance

Evidence that childhood maltreatment is associated with emotional and behavioral problems throughout childhood suggests that maltreatment could lead to impaired academic performance in middle and high school. This article explores these effects using data on siblings. An index measure of the intensity of childhood maltreatment was included as a covariate in multivariate analyses of adolescents' risk for school performance impairments. Family fixed effects were used to control for unobservables linked to family background and neighborhood effects. More intense childhood maltreatment was associated with greater probability of having a low GPA (P=0.001) and problems completing homework assignments (P=0.007). Associations between maltreatment intensity and adolescent school performance were not sensitive to model specification. Additional analyses suggested that maltreatment effects are moderated by cognitive deficits related to attention problems. The implications of these findings for educators and schools are discussed.     

运动和疾病中的肠液体吸收

前言 ２０世纪５０年代以来，人们发现肠里葡萄糖的存在促进钠的转运（Ｒｉｋｌｉｓ＆Ｑｕａｓｔｒｅｌ，１９５８），这个里程碑式的发现引发口服补水溶液配方的产生。为满足水、碳水化合物和电解质最大限度的吸收，精确配制这些溶液的问题激起了相当多的科学研究和讨论。 口服补水溶液一直是由葡萄糖、蔗糖、果糖、多精、谷物淀粉或由这些糖混合，并添加不同种类的电解质（如钢、氯、钾、柠檬酸盐、碳酸氢盐），而配制成低渗至高渗的溶液。这些溶液在十二指肠空肠、回肠和结肠的吸收。已在兔子、鼠、狗、猫和人身上得到了测试。 大多数的…