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In recent years, rapid advances in cardiac surgery and changes in attitude towards patients with cognitive disability have led to these patients receiving cardiac transplantation.This is a retrospective report describing the experience of four patients with Down Syndrome who received heart transplantation in a single institution.Anthracycline-induced cardiomyopathy was the most common cause of heart failure in this group (3/4). Two patients were bridged to transplantation, one by using a combination of extra-corporeal membrane oxygenation and biventricular assist device and the other by using a durable implantable left ventricular assist device. All the four patients are alive with the longest surviving patient 17 years after transplantation. Against strong hypothetical predictions, we observed no propensity for the development of post-transplant infections or lymphoproliferative disorders.Down Syndrome should not be the sole contraindication to heart transplantation. The decision for transplantation should be on a case-by-case basis provided adequate social support is in place.

Background Children with chronic kidney disease (CKD) have increased cardiovascular mortality. Identifying high-risk children who may benefit from further therapeutic intervention is difficult as cardiovascular abnormalities are subtle. Although transthoracic echocardiography may be used to detect sub-clinical abnormalities, it has well-known problems with reproducibility that limit its ability to accurately detect these changes. Cardiovascular magnetic resonance (CMR) is the reference standard method for assessing blood flow, cardiac structure and function. Furthermore, recent innovations enable the assessment of radial and longitudinal myocardial velocity, such that detection of sub-clinical changes is now possible. Thus, CMR may be ideal for cardiovascular assessment in pediatric CKD. This study aims to comprehensively assess cardiovascular function in pediatric CKD using CMR and determine its relationship with CKD severity. Methods A total of 120 children (40 mild, 40 moderate, 20 severe pre-dialysis CKD subjects and 20 healthy controls) underwent CMR with non-invasive blood pressure (BP) measurements. Cardiovascular parameters measured included systemic vascular resistance (SVR), total arterial compliance (TAC), left ventricular (LV) structure, ejection fraction (EF), cardiac timings, radial and longitudinal systolic and diastolic myocardial velocities. Between group comparisons and regression modelling were used to identify abnormalities in CKD and determine the effects of renal severity on myocardial function. Results The elevation in mean BP in CKD was accompanied by significantly increased afterload (SVR), without evidence of arterial stiffness (TAC) or increased fluid overload. Left ventricular volumes and global function were not abnormal in CKD. However, there was evidence of LV remodelling, prolongation of isovolumic relaxation time and reduced systolic and diastolic myocardial velocities. Conclusion Abnormal cardiovascular function is evident in pre-dialysis pediatric CKD. Novel CMR biomarkers may be useful for the detection of subtle abnormalities in this population. Further studies are needed to determine to prognostic value of these biomarkers. Electronic supplementary material The online version of this article (10.1186/s12968-018-0444-0) contains supplementary material, which is available to authorized users.

As the explosion growth of Internet economy, recommender system has become an important technology to solve the problem of information overload. However, recommenders are not one-size-fits-all, different recommenders have different virtues, making them be suitable for different users. In this paper, we propose a novel personalized recommender based on user preferences, which allows multiple recommenders to exist in E-commerce system simultaneously. We find that output of a recommender to each user is quite different when using different recommenders, the recommendation accuracy can be significantly improved if each user is assigned with his/her optimal personalized recommender. Furthermore, different from previous works focusing on short-term effects on recommender, we also evaluate the long-term effect of the proposed method by modeling the evolution of mutual feedback between user and online system. Finally, compared with single recommender running on the online system, the proposed method can improve the accuracy of recommendation significantly and get better trade-offs between short- and long-term performances of recommendation.

PURPOSE To develop and validate a rapid breath-hold tissue phase mapping (TPM) sequence. MATERIALS AND METHODS The sequence was based on an efficient uniform density spiral acquisition, combined with data acceleration. A novel acquisition and reconstruction strategy enabled combination of UNFOLD (2×) and SENSE (3×): UNFOLD-ed SENSE. The sequence was retrospectively cardiac-gated, and a graphics processing unit (GPU) was used for rapid "online" reconstruction. The optimal UNFOLD parameters for the data were calculated using an in silico model. The technique was validated on a 1.5T MR scanner in 15 patients with known aortic valve disease, against a respiratory self-navigated free-breathing TPM technique. Quantitative image quality measures (velocity-to-noise and edge sharpness) were made as well as calculation of longitudinal, radial, and tangential myocardial velocities in the left ventricle. RESULTS The proposed breath-hold TPM data took eight heartbeats to acquire. The breath-hold TPM images had significantly higher edge sharpness (P = 0.0014) than the self-navigated TPM images, but with significantly lower velocity-to-noise ratio (P 0.94) in the longitudinal, radial, and tangential velocities between the self-navigated data and the proposed breath-hold TPM sequence. CONCLUSION We demonstrate the feasibility of using spiral UNFOLD-ed SENSE to measure myocardial velocities using a rapid breath-hold spiral TPM sequence. This novel technique might enable accurate measurement of myocardial velocities, in a short scan time, which is especially important in a busy clinical workflow. J. MAGN. RESON. IMAGING 2016;44:1003-1009.

Cloud computing provides a promising approach for efficiently managing the performance of servers via advanced resource management, hence it becomes one of the important hotspots in high-performance computing field recently. For the existing performance management solutions of cloud servers, they always show inefficiency issues when dealing with the dynamic and burst web workloads. In this paper, we propose an autonomic performance management of cloud servers, which adopt the linear quadratic Gaussian with stochastic method (LQGwS). In the face of dynamic and burst web workloads, it guarantees the workload balance between different Web applications by adaptively adjusting the amount of resource allocation to each virtual machine. Furthermore, in order to deal with the unknown disturbances in the Web system, the LQGwS describes the Web system as a coupled multiple-input-multiple-output system and uses the Autoregressive moving-average model with exogenous inputs model (ARMAX) firstly, and then constructs the optimal resource allocation scheme based on minimizing an average cost function among a set of models, which are generated according to a Gauss distribution. Through the test of real network load, the results of this experiment on the XEN-based platform show that the proposed control strategy has better performance than existing solutions under dynamical workloads in terms of control accuracy and stability.

Introduction: The basis of late cardiovascular mortality following coarctation repair is poorly understood. Although hypertension has been implicated, peripheral systolic pressure (pSBP) has not been shown to be definitively higher in this group. This may be because mortality is more related to central systolic pressure (cSBP) than pSBP. We have developed a novel cardiovascular magnetic resonance (CMR) protocol that allows assessment of cSBP and it components: resistance, compliance and wave reflections. The main aims of this study were i) characterize hemodynamic differences between patients and controls ii) define hemodynamic determinants of cSBP in patients and iii) Identify possible biomarkers amongst covariates associated with LV mass (LVM). Methods: 75 subjects, 50 patients with repaired coarctation, median age 23.5yrs (74% male) and 25 matched controls; 21.0yrs (72% male) were recruited. Ascending aorta area and flow waveforms were obtained using a high temporal resolution (10ms) spiral phase-contrast MR flow sequence. This data was used to derive cSBP and perform wave intensity analysis (WIA) non-invasively using previously validated techniques. The determinants of cSBP and LVM were assessed using multivariable linear regression analysis. Results: Central SBP was significantly higher in patients compared to controls (115±13 vs 107±9mmHg [mean±sd], p=0.002). However, there was only a trend towards higher pSBP (123±15 vs 117±11mmHg, p=0.052). Patients had reduced arterial compliance, increased characteristic impedance and larger backward compression waves (BCW) than controls; and these parameters were independently associated with cSBP. LVM index was significantly higher in patients than controls (73.1±14.6 vs 58.9±9.7g/m 2 , p=0.0001). Independent predictors of LVM included cSBP (p=0.001) and BCW (p=0.002), but importantly not pSBP or coarctation index. Conclusions: Non-invasive assessment of fundamental arterial hemodynamics by CMR is feasible. Using these techniques we have shown elevated cSBP in patients after coarctation repair. Elevated cSBP and BCW are important determinants of increased LVM following coarctation repair. These metrics represent superior biomarkers of afterload than coarctation index and pSBP.