Stunning and Right Ventricular Dysfunction Is Induced by Coronary Balloon Occlusion and Rapid Pacing in Humans: Insights From Right Ventricular Conductance Catheter Studies

BACKGROUND: We sought to determine whether right ventricular stunning could be detected after supply (during coronary balloon occlusion [BO]) and supply/demand ischemia (induced by rapid pacing [RP] during transcatheter aortic valve replacement) in humans. METHODS AND RESULTS: Ten subjects with single-vessel right coronary artery disease undergoing percutaneous coronary intervention with normal ventricular function were studied in the BO group. Ten subjects undergoing transfemoral transcatheter aortic valve replacement were studied in the RP group. In both, a conductance catheter was placed into the right ventricle, and pressure volume loops were recorded at baseline and for intervals over 15 minutes after a low-pressure BO for 1 minute or a cumulative duration of RP for up to 1 minute. Ischemia-induced diastolic dysfunction was seen 1 minute after RP (end-diastolic pressure [mm Hg]: 8.1±4.2 versus 12.1±4.1, P<0.001) and BO (end-diastolic pressure [mm Hg]: 8.1±4.0 versus 8.7±4.0, P=0.03). Impairment of systolic and diastolic function after BO remained at 15-minutes recovery (ejection fraction [%]: 55.7±9.0 versus 47.8±6.3, P<0.01; end-diastolic pressure [mm Hg]: 8.1±4.0 versus 9.2±3.9, P<0.01). Persistent diastolic dysfunction was also evident in the RP group at 15-minutes recovery (end-diastolic pressure [mm Hg]: 8.1±4.1 versus 9.9±4.4, P=0.03) and there was also sustained impairment of load-independent indices of systolic function at 15 minutes after RP (end-systolic elastance and ventriculo-arterial coupling [mm Hg/mL]: 1.25±0.31 versus 0.85±0.43, P<0.01). CONCLUSIONS: RP and right coronary artery balloon occlusion both cause ischemic right ventricular dysfunction with stunning observed later during the procedure. This may have intraoperative implications in patients without right ventricular functional reserve

Uncertainty estimation for operational ocean forecast products-a multi-model ensemble for the North Sea and the Baltic Sea

Multi-model ensembles for sea surface temperature (SST), sea surface salinity (SSS), sea surface currents (SSC), and water transports have been developed for the North Sea and the Baltic Sea using outputs from several operational ocean forecasting models provided by different institutes. The individual models differ in model code, resolution, boundary conditions, atmospheric forcing, and data assimilation. The ensembles are produced on a daily basis. Daily statistics are calculated for each parameter giving information about the spread of the forecasts with standard deviation, ensemble mean and median, and coefficient of variation. High forecast uncertainty, i.e., for SSS and SSC, was found in the Skagerrak, Kattegat (Transition Area between North Sea and Baltic Sea), and the Norwegian Channel. Based on the data collected, longer-term statistical analyses have been done, such as a comparison with satellite data for SST and evaluation of the deviation between forecasts in temporal and spatial scale. Regions of high forecast uncertainty for SSS and SSC have been detected in the Transition Area and the Norwegian Channel where a large spread between the models might evolve due to differences in simulating the frontal structures and their movements. A distinct seasonal pattern could be distinguished for SST with high uncertainty between the forecasts during summer. Forecasts with relatively high deviation from the multi-model ensemble (MME) products or the other individual forecasts were detected for each region and each parameter. The comparison with satellite data showed that the error of the MME products is lowest compared to those of the ensemble members

Improved spectrum sensing for OFDM cognitive radio in the presence of timing offset

Spectrum sensing is an important aspect of an (interweave) cognitive radio network. In the particular case of orthogonal frequency division multiplexing (OFDM) transmission, many previous spectrum sensing algorithms have utilized the unique correlation properties provided by the cyclic prefix (CP). However, they have also had to both estimate and compensate for the inherent timing offset of a practical system. This is because the timing offset will affect both the test statistic and the threshold, and the inaccurate estimation of timing offset will lead to poor performance. So in this paper, we propose an improved CP detector by constructing a likelihood ratio test (LRT) based on the multivariate probability density functions (pdf) of a particular auto-correlation vector that is chosen to exploit the existence of the CP. This leads to ‘probability of detection’ (Pd) and ‘probability of false alarm’ (Pf) terms that are actually independent of timing offset, and we can get an accurate threshold without estimating timing offset. Simulation results illustrate that the proposed algorithm outperforms existing methods, even for low SNR values. Finally, we show how the algorithm’s parameters must be carefully chosen in a trade-off between spectrum sensing success and overall system performance

Selective reporting: a half signalling load algorithm for distributed sensing

Spectrum sensing is a powerful tool of the cognitive cycle to help circumvent the apparent spectrum scarcity faced by wireless transmission systems. To overcome the challenging issues faced by the localized sensing, multiple cognitive radios can cooperate to explore the multiuser diversity and generate a more reliable decision on the presence of a signal in the frequencies of interest. In such a cooperative sensing scenario, a common reporting channel is needed for the transmission of the information of each element. As the number of elements that participate in the sensing operation increases, so does the bandwidth demanded for the reporting channel, quickly becoming the limiting factor in this scenario. To tackle the issue of reducing the sensing report overhead, this paper introduces a new cooperative sensing scheme that introduces silence periods in the reporting and, relying on information theory principles, explores the information present in these periods to reduce by 50% the sensing reporting overhead while maintaining the same performance of standard reporting schemes. Numerical and experimental results confirm the theoretical analysis and show the predicted reduction in reporting overhead and performance preservation

‘Kamikaze’ heritage tourism in Japan: A pathway to peace and understanding?

Reflecting the wider belief that international tourism offers the opportunity to encourage peace and understanding amongst peoples and nations, one objective of Japan’s recent tourism development policy is the enhancement of mutual understanding and the promotion of international peace. The purpose of this paper is to consider the extent to which this objective is achievable, particularly in the context of continuing controversy surrounding the country’s confrontation of its twentieth century military heritage in general and its role in the Pacific War in particular. Based on research at two ‘difficult’ heritage sites, Chiran Peace Museum in Kagoshima Prefecture and Yūshūkan War Museum in Tokyo, it explores specifically how the kamikaze phenomenon is commemorated and interpreted for international visitors, in so doing revealing a significant degree of dissonance at both sites. Not only is a selective narrative of heroic sacrifice presented within a wider revisionist history of the Pacific War but also no attempt is made to acknowledge the prevailing cultural context that might underpin a more nuanced understanding of the kamikaze. Hence, the paper concludes that a meaningful opportunity to enhance international understanding has been missed

Acceptability and Feasibility of a Mindfulness Intervention Delivered via Videoconferencing for People With Parkinson's

Mindfulness-based group therapy is a rapidly growing psychological approach that can potentially help people adjust to chronic illness and manage unpleasant symptoms. Emerging evidence suggests that mindfulness-based interventions may benefit people with Parkinson’s. The objective of the paper is to examine the appropriateness, feasibility, and potential cost-effectiveness of an online mindfulness intervention, designed to reduce anxiety and depression for people with Parkinson’s. We conducted a feasibility randomized control trial and qualitative interviews. Anxiety, depression, pain, insomnia, fatigue, impact on daily activities and health-related quality of life were measured at baseline, 4, 8, and 20 weeks. Semi-structured interviews were conducted at the end of the intervention. Participants were randomized to the Skype delivered mindfulness group (n = 30) or wait-list (n = 30). Participants in the mindfulness group were also given a mindfulness manual and a CD with mindfulness meditations. The intervention did not show any significant effects in the primary or secondary outcome measures. However, there was a significant increase in the quality of life measure. The incremental cost-effectiveness ratio was estimated to be £27,107 per Quality-Adjusted Life Year gained. Also, the qualitative study showed that mindfulness is a suitable and acceptable intervention. It appears feasible to run a trial delivering mindfulness through Skype, and people with Parkinson’s found the sessions acceptable and helpful

Derivation of High Purity Neuronal Progenitors from Human Embryonic Stem Cells

The availability of human neuronal progenitors (hNPs) in high purity would greatly facilitate neuronal drug discovery and developmental studies, as well as cell replacement strategies for neurodegenerative diseases and conditions, such as spinal cord injury, stroke, Parkinson's disease, Alzheimer's disease, and Huntington's disease. Here we describe for the first time a method for producing hNPs in large quantity and high purity from human embryonic stem cells (hESCs) in feeder-free conditions, without the use of exogenous noggin, sonic hedgehog or analogs, rendering the process clinically compliant. The resulting population displays characteristic neuronal-specific markers. When allowed to spontaneously differentiate into neuronal subtypes in vitro, cholinergic, serotonergic, dopaminergic and/or noradrenergic, and medium spiny striatal neurons were observed. When transplanted into the injured spinal cord the hNPs survived, integrated into host tissue, and matured into a variety of neuronal subtypes. Our method of deriving neuronal progenitors from hESCs renders the process amenable to therapeutic and commercial use