IMPACT OF VIDEO RESOLUTION CHANGES ON QoE FOR ADAPTIVE VIDEO STREAMING

HTTP adaptive streaming (HAS) has become the de-facto standard for video streaming to ensure continuous multimedia service delivery under irregularly changing network conditions. Many studies already investigated the detrimental impact of various playback characteristics on the Quality of Experience of end users, such as initial loading, stalling or quality variations. However, dedicated studies tackling the impact of resolution adaptation are still missing. This paper presents the results of an immersive audiovisual quality assessment test comprising 84 test sequences from four different video content types, emulated with an HAS adaptation mechanism. We employed a novel approach based on systematic creation of adaptivity conditions which were assigned to source sequences based on their spatio-temporal characteristics. Our experiment investigates the resolution switch effect with respect to the degradations in MOS for certain adaptation patterns. We further demonstrate that the content type and resolution change patterns have a significant impact on the perception of resolution changes. These findings will help develop better QoE models and adaptation mechanisms for HAS systems in the future

Effects of MitraClip on cognitive and psychological function in heart failure patients: the sicker the better

Purpose: Cognitive impairment and reduced quality of life is a common condition in patients with heart failure (HF). Percutaneous mitral valve repair using (PMVR) MitraClip (MC) has emerged as a promising interventional tool, reducing all-cause mortality and hospitalization as well as increasing cognitive functioning and quality of life. However, the benefit of HF patients with severely depressed cognitive functioning remains unknown. Methods: We assessed cognitive functioning (figural memory—FGT, executive function—TOL, TMT B), psychosocial functioning (depression—PHQ-9, quality of life—SF36), and clinical parameters (echocardiography, 6-min walk test distance, and cardiac biomarkers) 1 day before (t0) and 6 weeks after (t1) MC intervention in HF patients (n = 40). First, paired sample t tests were conducted to uncover improvements in cognitive functioning post-MC intervention. Second, the COGBAT Norm-sample, a representative age-matched healthy sample, was used to compare participants’ individual scores. Third, bivariate linear regressions were calculated for all key predictors of the detected improvements in cognitive functioning post-MC intervention (t1–t0). Results: Following the MC intervention, we found significant improvements in figural memory, executive functioning, and psychosocial functioning. Most of the patients with depressed executive functioning before the MC intervention showed post-intervention test scores within the normal range (> 50th percentile; t0 22.5% vs. t1 60%) as compared to the normative COGBAT sample. Regression analyses revealed that lower baseline scores in planning ability before the MC intervention (t0) were associated with greater planning ability (TOL; B = − 0.78, 95% CI − 1.04 to − 0.53), figural memory (FGT; B = − 0.26, 95% CI − 0.44 to − 0.07), and cognitive flexibility (TMT B; B = − 0.36, 95% CI − 0.50 to − 0.23) improvement post-MC intervention (t1–t0). Psychosocial functioning and age were not associated with these improvements. Conclusions: Patients with depressed executive functioning showed the greatest benefit from the MC intervention regarding cognitive functioning. Age and psychological functioning seem less important for cognitive performance improvements post-MC intervention. Hence, severely depressed cognitive functioning in patients is not a contraindication for PMVR using MitraClip

Cell Therapy for Cardiovascular Disease: A Comparison of Methods of Delivery

The field of myocardial regeneration utilizing novel cell-based therapies, gene transfer, and growth factors may prove to play an important role in the future management of ischemic heart disease and cardiomyopathy. Phases I and II clinical trials have been published for a variety of biologics utilizing four methods of delivery: systemic infusion, intracoronary infusion, transvenous coronary sinus, and intramyocardial. This review discusses the advantages and disadvantages of the delivery approaches above

COVID-19 among heart transplant recipients in Germany: a multicenter survey

Abstract Aims Heart transplantation may represent a particular risk factor for severe coronavirus infectious disease 2019 (COVID-19) due to chronic immunosuppression and frequent comorbidities. We conducted a nation-wide survey of all heart transplant centers in Germany presenting the clinical characteristics of heart transplant recipients with COVID-19 during the first months of the pandemic in Germany. Methods and results A multicenter survey of all heart transplant centers in Germany evaluating the current status of COVID-19 among adult heart transplant recipients was performed. A total of 21 heart transplant patients with COVID-19 was reported to the transplant centers during the first months of the pandemic in Germany. Mean patient age was 58.6 ± 12.3 years and 81.0% were male. Comorbidities included arterial hypertension (71.4%), dyslipidemia (71.4%), diabetes mellitus (33.3%), chronic kidney failure requiring dialysis (28.6%) and chronic-obstructive lung disease/asthma (19.0%). Most patients received an immunosuppressive drug regimen consisting of a calcineurin inhibitor (71.4%), mycophenolate mofetil (85.7%) and steroids (71.4%). Eight of 21 patients (38.1%) displayed a severe course needing invasive mechanical ventilation. Those patients showed a high mortality (87.5%) which was associated with right ventricular dysfunction (62.5% vs. 7.7%; p = 0.014), arrhythmias (50.0% vs. none; p = 0.012), and thromboembolic events (50.0% vs. none; p = 0.012). Elevated high-sensitivity cardiac troponin T- and N-terminal prohormone of brain natriuretic peptide were significantly associated with the severe form of COVID-19 (p = 0.017 and p < 0.001, respectively). Conclusion Severe course of COVID-19 was frequent in heart transplanted patients. High mortality was associated with right ventricular dysfunction, arrhythmias, thromboembolic events, and markedly elevated cardiac biomarkers