Iron induces insulin resistance in cardiomyocytes via regulation of oxidative stress

York University Librarie

Selection of the Most Probable Best

We consider an expected-value ranking and selection problem where all k solutions' simulation outputs depend on a common uncertain input model. Given that the uncertainty of the input model is captured by a probability simplex on a finite support, we define the most probable best (MPB) to be the solution whose probability of being optimal is the largest. To devise an efficient sampling algorithm to find the MPB, we first derive a lower bound to the large deviation rate of the probability of falsely selecting the MPB, then formulate an optimal computing budget allocation (OCBA) problem to find the optimal static sampling ratios for all solution-input model pairs that maximize the lower bound. We devise a series of sequential algorithms that apply interpretable and computationally efficient sampling rules and prove their sampling ratios achieve the optimality conditions for the OCBA problem as the simulation budget increases. The algorithms are benchmarked against a state-of-the-art sequential sampling algorithm designed for contextual ranking and selection problems and demonstrated to have superior empirical performances at finding the MPB

Optimal Precoder Designs for Sum-utility Maximization in SWIPT-enabled Multi-user MIMO Cognitive Radio Networks

In this paper, we propose a generalized framework that combines the cognitive radio (CR) techniques for spectrum sharing and the simultaneous wireless information and power transfer (SWIPT) for energy harvesting (EH) in the conventional multi-user MIMO (MuMIMO) channels, which leads to an MuMIMO-CR-SWIPT network. In this system, we have one secondary base-station (S-BS) that supports multiple secondary information decoding (S-ID) and secondary EH (S-EH) users simultaneously under the condition that interference power that affects the primary ID (P-ID) receivers should stay below a certain threshold. The goal of the paper is to develop a generalized precoder design that maximizes the sum-utility cost function under the transmit power constraint at the S-BS, and the EH constraint at each S-EH user, and the interference power constraint at each P-ID user. Therefore, the previous studies for the CR and SWIPT systems are casted as particular solutions of the proposed framework. The problem is inherently non-convex and even the weighted minimum mean squared error (WMMSE) transformation does not resolve the non-convexity of the original problem. To tackle the problem, we find a solution from the dual optimization via sub-gradient ellipsoid method based on the observation that the WMMSE transformation raises zero-duality gap between the primal and the dual problems. We also propose a simplified algorithm for the case of a single S-ID user, which is shown to achieve the global optimum. Finally, we demonstrate the optimality and efficiency of the proposed algorithms through numerical simulation results.Comment: 12pages, 9 figures, submitted to IEEE Systems Journa

Percutaneous cryoablation for hepatocellular carcinoma

Local ablation therapy is considered as a conventional treatment option for patients with early stage hepatocellular carcinoma (HCC). Although radiofrequency (RF) ablation is widely used for HCC, the use of cryoablation has been increasing as newer and safer cryoablation systems have developed. The thermodynamic mechanism of freezing and thawing used in cryoablation is the Joule-Thomson effect. Cryoablation destroys tissue via direct tissue destruction and vascular-related injury. A few recent comparative studies have shown that percutaneous cryoablation for HCCs is comparable to percutaneous RF ablation in terms of long term therapeutic outcomes and complications. Cryoablation has several advantages over RF ablation such as well visualization of iceball, no causation of severe pain, and lack of severe damage to great vessels and gallbladder. It is important to know the advantages and disadvantages of cryoablation compared with RF ablation for improvement of therapeutic efficacy and safety

Sapovirus translation requires an interaction between VPg and the cap binding protein eIF4E.

UNLABELLED: Sapoviruses of the Caliciviridae family of small RNA viruses are emerging pathogens that cause gastroenteritis in humans and animals. Molecular studies on human sapovirus have been hampered due to the lack of a cell culture system. In contrast, porcine sapovirus (PSaV) can be grown in cell culture, making it a suitable model for understanding the infectious cycle of sapoviruses and the related enteric caliciviruses. Caliciviruses are known to use a novel mechanism of protein synthesis that relies on the interaction of cellular translation initiation factors with the virus genome-encoded viral protein genome (VPg) protein, which is covalently linked to the 5' end of the viral genome. Using PSaV as a representative member of the Sapovirus genus, we characterized the role of the viral VPg protein in sapovirus translation. As observed for other caliciviruses, the PSaV genome was found to be covalently linked to VPg, and this linkage was required for the translation and the infectivity of viral RNA. The PSaV VPg protein was associated with the 4F subunit of the eukaryotic translation initiation factor (eIF4F) complex in infected cells and bound directly to the eIF4E protein. As has been previously demonstrated for feline calicivirus, a member of the Vesivirus genus, PSaV translation required eIF4E and the interaction between eIF4E and eIF4G. Overall, our study provides new insights into the novel mechanism of sapovirus translation, suggesting that sapovirus VPg can hijack the cellular translation initiation mechanism by recruiting the eIF4F complex through a direct eIF4E interaction. IMPORTANCE: Sapoviruses, which are members of the Caliciviridae family, are one of the causative agents of viral gastroenteritis in humans. However, human sapovirus remains noncultivable in cell culture, hampering the ability to characterize the virus infectious cycle. Here, we show that the VPg protein from porcine sapovirus, the only cultivatable sapovirus, is essential for viral translation and functions via a direct interaction with the cellular translation initiation factor eIF4E. This work provides new insights into the novel protein-primed mechanism of calicivirus VPg-dependent translation initiation.This work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Science, ICT and Future Planning (NRF-2014R1A2A2A01004292), and by the Wellcome Trust (Ref: WT097997MA). IG is a Wellcome senior fellow. The authors would like to thank Professor Jeong-Sun Kim for providing reagents and critical input into the project.This is the accepted manuscript version of the article. The final version is available from ASM at http://jvi.asm.org/content/early/2014/08/18/JVI.01650-14.abstract

Transient Increase of Higher-Order Aberrations after Lateral Rectus Recession in Children

The changes of higher-order aberrations (HOAs) after bilateral lateral rectus muscle recession were evaluated. Forty eyes of 20 children were enrolled and their wavefront information was assessed until postoperative 3 months. Even though the root mean square (RMS) of total aberration was not changed, the RMS of HOA was transiently increased at postoperative 1 week and returned to baseline level after 1 month. Among individual Zernike coefficient, secondary astigmatism, quadrafoil, secondary coma, secondary trefoil, and pentafoil showed similar tendency with the RMS of HOA. However, coma, trefoil, and spherical aberration were not changed. Regarding recession amount, it did not correlate with any Zernike coefficient. In summary, our data imply that the HOAs are transiently increased after lateral rectus recession surgery. These results are in collusion with previous reports that strabismus surgery induced transient corneal astigmatism