Model Risk, Mortality Heterogeneity, and Implications for Solvency and Tail risk

Mortality models used to assess longevity risk and retirement funding have been extended to stochastic models with trends and systematic risk. Systematic risk cannot be readily diversified in an insurance pool or pension fund. It is an important factor in assessing solvency and highlighting the tail risk in longevity insurance and pension products. Idiosyncratic risk can be diversified in typical pool sizes, although less effectively at the older ages. Mortality heterogeneity is not usually taken into account in stochastic mortality models. This is a mortality risk that reduces the effectiveness of idiosyncratic mortality risk pooling. Heterogeneity has been modeled with frailty models and more recently with Markov multiple state ageing models. This paper overviews recent developments in models for mortality heterogeneity and uses a model calibrated to both population mortality and health condition data to consider the impact of model risk and heterogeneity in assessing solvency and tail risk for longevity risk products

High Volumetric Performance Supercapacitors with Controlled Nanomorphology

Supercapacitor is one of the promising energy storage devices due to its relatively higher energy density compared with dielectric capacitor and higher power density and longer cycle life time (>millions) than conventional battery. In order to satisfy various requirements for energy technologies, supercapacitors with higher energy and power densities are required. In this chapter, we improved the electrochemical performance largely compared with commercial product through controlling the nanomorphology of cells. Meanwhile, although many past research programs have focused mainly on gravimetric energy densities, here we have also devoted efforts to study and develop nanomorphologic structures to realize high volumetric energy and power densities, since device volume is another critical and key performance parameter. Moreover, fundamental studies have been carried out on the mobile ion transport and storage in the nanostructures developed in this chapter

RT-SRTS: Angle-Agnostic Real-Time Simultaneous 3D Reconstruction and Tumor Segmentation from Single X-Ray Projection

Radiotherapy is one of the primary treatment methods for tumors, but the organ movement caused by respiration limits its accuracy. Recently, 3D imaging from a single X-ray projection has received extensive attention as a promising approach to address this issue. However, current methods can only reconstruct 3D images without directly locating the tumor and are only validated for fixed-angle imaging, which fails to fully meet the requirements of motion control in radiotherapy. In this study, a novel imaging method RT-SRTS is proposed which integrates 3D imaging and tumor segmentation into one network based on multi-task learning (MTL) and achieves real-time simultaneous 3D reconstruction and tumor segmentation from a single X-ray projection at any angle. Furthermore, the attention enhanced calibrator (AEC) and uncertain-region elaboration (URE) modules have been proposed to aid feature extraction and improve segmentation accuracy. The proposed method was evaluated on fifteen patient cases and compared with three state-of-the-art methods. It not only delivers superior 3D reconstruction but also demonstrates commendable tumor segmentation results. Simultaneous reconstruction and segmentation can be completed in approximately 70 ms, significantly faster than the required time threshold for real-time tumor tracking. The efficacies of both AEC and URE have also been validated in ablation studies. The code of work is available at https://github.com/ZywooSimple/RT-SRTS

Heat Transfer Analysis of Passive Residual Heat Removal Heat Exchanger under Natural Convection Condition in Tank

Aiming at the heat transfer calculation of the Passive Residual Heat Removal Heat Exchanger (PRHR HX), experiments on the heat transfer of C-shaped tube immerged in a water tank were performed. Comparisons of different correlation in literatures with the experimental data were carried out. It can be concluded that the Dittus-Boelter correlation provides a best-estimate fit with the experimental results. The average error is about 0.35%. For the tube outside, the McAdams correlations for both horizontal and vertical regions are best-estimated. The average errors are about 0.55% for horizontal region and about 3.28% for vertical region. The tank mixing characteristics were also investigated in present work. It can be concluded that the tank fluid rose gradually which leads to a thermal stratification phenomenon

Revisit security in the era of DevOps : An evidence-based inquiry into DevSecOps industry

By adopting agile and lean practices, DevOps aims to achieve rapid value delivery by speeding up development and deployment cycles, which however lead to more security concerns that cannot be fully addressed by an isolated security role only in the final stage of development. DevSecOps promotes security as a shared responsibility integrated into the DevOps process that seamlessly intertwines development, operations, and security from the start throughout to the end of cycles. While some companies have already begun to embrace this new strategy, both industry and academia are still seeking a common understanding of the DevSecOps movement. The goal of this study is to report the state-of-the-practice of DevSecOps, including the impact of DevOps on security, practitioners' understanding of DevSecOps, and the practices associated with DevSecOps as well as the challenges of implementing DevSecOps. The authors used a mixed-methods approach for this research. The authors carried out a grey literature review on DevSecOps, and surveyed the practitioners of DevSecOps in industry of China. The status quo of DevSecOps in industry is summarized. Three major software security risks are identified with DevOps, where the establishment of DevOps pipeline provides opportunities for security-related activities. The authors classify the interpretations of DevSecOps into three core aspects of DevSecOps capabilities, cultural enablers, and technological enablers. To materialise the interpretations into daily software production activities, the recommended DevSecOps practices from three perspectives—people, process, and technology. Although a preliminary consensus is that DevSecOps is regarded as an extension of DevOps, there is a debate on whether DevSecOps is a superfluous term. While DevSecOps is attracting an increasing attention by industry, it is still in its infancy and more effort needs to be invested to promote it in both research and industry communities

Proximal buddy in jail technique: A bail out technique to increase guide support

  Background: During percutaneous coronary intervention, “buddy-in-jail” technique is often used to facilitate stent delivery in complex coronary artery lesions. However, the safety and efficacy of this tech­nique when used with different jailed wire and applied in different target vessel lesions remain elusive. The aim of this retrospective study was to analyze the effectiveness of “buddy-in-jail” technique in the tortuous and rigid lesions of both the common and neighboring coronary arteries. The effectiveness between hydrophilic-coated and non-hydrophilic-coated guide wire as jailed wires was also compared. Methods: The “buddy-in-jail” technique was applied in 15 patients after failed balloon or stent delivery into the target vessel lesion from June 2014 to December 2016. The safety and effectiveness of the “bud­dy-in-jail” technique was compared in the tortuous and rigid lesions of both the common and neighbor­ing coronary arteries and between hydrophilic-coated and non-hydrophilic-coated “jailed” wires. Results: Stent delivery was successful in 13 (86.7%) patients with the use of “buddy-in-jail” technique. The success rate was similar to the group using the common artery (87.5%) as a “buddy” vessel and the group using a neighboring artery (85.7%) as a “buddy” vessel (p > 0.05), and between hydrophilic- -coated (100%) and non-hydrophilic-coated “jailed” wire (77.8%) group (p > 0.05). All wires were successfully extracted without complications. Conclusions: The “buddy-in-jail” technique offers a potential alternative approach for the distal stent delivery in both the common and neighboring coronary arteries. Also, both hydrophilic and non-hydro­philic-coated wire could be safely and effectively used as “jailed” wire.

Chronic vagus nerve stimulation in patients with heart failure: challenge or failed translation?

Autonomic imbalance between the sympathetic and parasympathetic nervous systems contributes to the progression of chronic heart failure (HF). Preclinical studies have demonstrated that various neuromodulation strategies may exert beneficial cardioprotective effects in preclinical models of HF. Based on these encouraging experimental data, vagus nerve stimulation (VNS) has been assessed in patients with HF with a reduced ejection fraction. Nevertheless, the main trials conducted thus far have yielded conflicting findings, questioning the clinical efficacy of VNS in this context. This review will therefore focus on the role of the autonomic nervous system in HF pathophysiology and VNS therapy, highlighting the potential reasons behind the discrepancy between preclinical and clinical studies

Dynamical Variations of the Global COVID-19 Pandemic Based on a SEICR Disease Model: A New Approach of Yi Hua Jie Mu

The ongoing coronavirus disease 2019 (COVID-19) pandemic has caused more than 150 million cases of infection to date and poses a serious threat to global public health. In this study, global COVID-19 data were used to examine the dynamical variations from the perspectives of immunity and contact of 84 countries across the five climate regions: tropical, arid, temperate, and cold. A new approach named Yi Hua Jie Mu is proposed to obtain the transmission rates based on the COVID-19 data between the countries with the same climate region over the Northern Hemisphere and Southern Hemisphere. Our results suggest that the COVID-19 pandemic will persist over a long period of time or enter into regular circulation in multiple periods of 1–2 years. Moreover, based on the simulated results by the COVID-19 data, it is found that the temperate and cold climate regions have higher infection rates than the tropical and arid climate regions, which indicates that climate may modulate the transmission of COVID-19. The role of the climate on the COVID-19 variations should be concluded with more data and more cautions. The non-pharmaceutical interventions still play the key role in controlling and prevention this global pandemic