Zobrazení zdroje stránky Dickensroche8368

This article studies the containment control problem for a group of linear systems, consisting of more than one leader, over switching topologies. The input matrices of these linear systems are not required to have full-row rank and the switching can be arbitrary, making the problem quite general and challenging. We propose a novel analysis framework from the viewpoint of a state transition matrix. Specifically, according to the inherent linearity, we successfully establish a connection between state transition matrices of the above multileader system and a virtual leader-following system obtained by combining those leaders. This enlightening result relates the containment problem to a consensus one. Then, by analyzing the property of the state transition matrix, we uncover that each component of any follower's state converges to the convex hull spanned by the corresponding components of the leaders', provided some mild conditions are satisfied. These conditions are derived in terms of the concept of a positive linear system. A special case of the second-order linear system is further discussed to illustrate these conditions. Moreover, two different design methods of the feedback gain matrix are provided, which additionally require that the network topology contains a united spanning tree all the time.This article addresses the problem of global stabilization of continuous-time linear systems subject to control constraints using a model-free approach. We propose a gain-scheduled low-gain feedback scheme that prevents saturation from occurring and achieves global stabilization. The framework of parameterized algebraic Riccati equations (AREs) is employed to design the low-gain feedback control laws. An adaptive dynamic programming (ADP) method is presented to find the solution of the parameterized ARE without requiring the knowledge of the system dynamics. In particular, we present an iterative ADP algorithm that searches for an appropriate value of the low-gain parameter and iteratively solves the parameterized ADP Bellman equation. We present both state feedback and output feedback algorithms. The closed-loop stability and the convergence of the algorithm to the nominal solution of the parameterized ARE are shown. The simulation results validate the effectiveness of the proposed scheme.This article addresses the formation control problem of flapping-wing vehicles (FWVs) under the model uncertainty and the measurement inaccuracy. A two-layer formation strategy is adopted, which consists of a formation control layer for the leaders, and a containment control layer for the followers. In both layers, attitudes and positions are required by the formation geometry. A formation state estimation algorithm is designed to achieve the desired formation states from local neighborhoods. In FWVs, attitude angles are usually achieved from angular velocities, whose measurement error accumulates during integration and leads to divergence of the system. In order to solve this problem, we explore the coupling property between the translational motion and the rotational motion of FWVs, and design a coupling-based estimation method for attitude angles. To compensate for the model uncertainty, the measurement error, and the estimation error, adaptive neural networks are developed together with the control algorithm. The stability of both the control algorithm and the estimation algorithm is guaranteed based on the Lyapunov stability theory. Simulations are conducted to validate our method, and the results illustrate its effectiveness.Preimplantation genetic diagnosis (PGD) is a technique that is commonly used during assisted reproduction in the clinics to eliminate genetically abnormal embryos before implantation. The blastomere biopsy technique has risks related to the embryo, but blastocyst biopsy has not been systematically evaluated in relation to effects after birth, and the resulting offspring have not been followed up on. We designed a series of experiments to evaluate the risk of blastocyst biopsy on the resulting progeny. Mice were divided into a PGD group and a control group. The former was the progeny of mice that underwent blastocyst biopsy and the latter was delivered through a normal pregnancy without blastocyst biopsy. Each group consisted of 15 animals. We found no effects of blastocyst biopsy on reproductive capacities and weight gain. [https://www.selleckchem.com/products/gw0742.html GW0742 datasheet] As for neurobehavioral evaluation between both groups, there were no significant differences in tail suspension test, sucrose preference test, the open field test and the elevated plus maze. Western blotting, immunohistochemistry and quantitative RT-PCR results showed that the expression levels of MBP, PRDX5 and UCHL1 in the PGD group were not significantly different compared to the control group, but SNAP-α expression in the PGD group was lower than that in control group. In summary, we concluded that blastocyst biopsy had no adverse effect on the general growth and behavior in mice. However, blastocyst biopsy effected the expression of SNAP-α. Therefore, the safety of blastocyst biopsy requires further evaluation.Screening is imperative to safeguard patients, practitioners and staff.•Various tests available for screening and diagnosing patients for SARS-CoV-2.•Rapid test can be used to screen patients before any surgical intervention.•Along with testing, clinical features should be corroborated.•Oral findings might aid in early diagnosis of COVID-19.Background Previous studies have shown the healthcare utilization for medically refractory epilepsy and epilepsy surgery until 2012 with disparities according to race/ethnicity and socioeconomic status. To extend these data and add other utilization information, we retrospectively investigated the nationwide trends in hospitalization and readmission during 2010-2015. Method We extracted data on inpatients who were diagnosed with epilepsy and those who received epilepsy surgery using the national inpatient sample and nationwide readmission database during 2010-2015. We estimated healthcare utilization related to pediatric epilepsy, the number of epilepsy surgeries, hospitalization rates and 30-day readmission rates. Results 100,000-120,000 children were hospitalized due to epilepsy each year. Hospitalization rates and 30-day readmission rates were 214.6-262.3 per 1000 patient-years and 72.4-78.0 per 1000 discharges, respectively. 1400-2000 children with epilepsy received epilepsy surgery, but the proportions of medically refractory epilepsy were estimated as 0.8 %-1.2 %. Disparities in patients receiving epilepsy surgery by race/ethnicity were observed during 2010-2012, but they were not after 2013. Children with higher household income levels had consistently higher proportions of receiving epilepsy surgery than those with lower levels. The hospitalization costs for epilepsy surgery were constant at $55,780-$60,813 after adjusting for healthcare cost inflation, whereas the cost for epilepsy were slightly elevated from $15,984 to $17,426. Conclusions We provide novel insights into the current healthcare utilization for epilepsy and epilepsy surgery. Although the disparity of epilepsy surgery seemed to be mitigated, surgery in children with medically refractory epilepsy was still underutilized.Objective Gaining insight into contextual factors and mechanisms supporting or hindering autonomy supportive consultation and into outcomes of such consultations. Methods We conducted a systematic review using the realist synthesis procedure according to RAMESES guideline. A search was performed in PubMed, Embase, PsycINFO and Cinahl from inception to March 2019 using the search terms 'autonomy' AND 'support' AND 'consultation' OR 'communication' AND 'intervention'. The review process including paper selection, quality assessment, full text reading for data-extraction was conducted by two researchers independently. Results Of 2792 articles, 18 met our inclusion criteria. Contextual factors influencing an autonomy supportive consultation were work organization and the attitude of professionals. An overarching supporting mechanism for AS was relationship building. In addition, each phase of the decision-making process seems to need supporting mechanisms fulfilling patients 'specific psychological needs in that phase. The outcome of AS is higher levels of patient well-being. Conclusion Autonomy supportive consultation works under various contexts coupled with mechanisms that give rise to favourable-outcomes, of which relationship building, taking time and exploring patients' needs seem the most important. Practice implications The results of our review facilitate professionals to reflect on their autonomy supportive consultation skills, which could improve their autonomy supportive behaviour.Objectives Adolescents and young adults account for 50% of new infections with sexually transmitted infection (STI), while representing only 25% of the sexually active population. An evaluation of sexual behavior, STI knowledge and infection among youth of different age groups is relevant to formulate effective sexual health strategies. Methods In this monocentric, open, prospective cross-sectional study, 268 asymptomatic subjects (14-30 years) were partitioned into three cohorts I 14-19 (n=42), II 20-25 (n=147) and III 25-30 (n=79) years. A comparative analysis of their sexual behavior and STI knowledge was performed using a 21-item questionnaire at the WIR-Center for Sexual Health and Medicine. Prevalence of chlamydia and gonococcal infections were tested, using the Cepheid Xpert® CT/NG assay. Results The three age-specific cohorts showed statistically significant differences in their relationship status, their sexual contacts and the number of life-time sexual partners. Independent of age, men who have sex with men had greater number of sexual partners across all age groups. Although &gt;95% of participants were aware of HIV in all age groups, the corresponding awareness of non-HIV STI was consistently lower in cohort I. The awareness of trichomonas, mycoplasma and candida in particular was less then 50% across all agedemographies. Chlamydia screening remains poor despite current chlamydia infection among cohort I, II &amp; III being 7.1%, 5.4%, &amp; 11.4% respectively. Conclusion Our study demonstrates a demographic divide in the knowledge on most frequent STI apart from HIV. Current education, screening and vaccination programs for STI among the younger demographic should be improved.Children who receive peritoneal dialysis (PD) are at increased risk for thyroid dysfunction. A rarely appreciated cause is iodine overload. We report 4 children who developed iodine overload and secondary hypothyroidism. All had kidney failure treated by PD. Each previously had normal thyroid function screening test results. At the time hypothyroidism was detected, the duration of PD ranged from 1 week to 27 months (median, 6 months). Three children had high thyrotropin values and all had high serum iodine levels. The sole source of iodine exposure in each child was a povidone-iodine-impregnated gauze in the sterile transfer set cap associated with PD. Iodine overload is a poorly appreciated problem associated with the provision of PD in infants and small children and can lead to thyroid dysfunction. Increased awareness among pediatric nephrologists should lead to the development of optimal monitoring and prevention recommendations.