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Impact of the COVID‑19 outbreak on the US equity sectors:Evidence from quantile return spillovers

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Financial Innovation 2021年第1期7卷 300-322页

作者： Syed Jawad Hussain Shahzad elie bouri Ladislav Kristoufek Tareq Saeed Montpellier Business School University of MontpellierMontpellier Research in ManagementMontpellierFrance South Ural State University ChelyabinsRussian Federation Adnan Kassar School of Business Lebanese American UniversityBeirutLebanon Institute of Information Theory and Automation The Czech Academy of SciencesPragueCzech Republic Institute of Economic Studies Faculty of Social SciencesCharles UniversityPragueCzech Republic Nonlinear Analysis and Applied Mathematics(NAAM)‑Research Group Department of MathematicsFaculty of ScienceKing Abdulaziz UniversityJeddahSaudi Arabia

The aim of this study is to examine the extreme return spillovers among the US stock market sectors in the light of the COVID-19 *** this end,we extend the now-traditional Diebold-Yilmaz spillover index to the quantiles domain by building networks of generalized forecast error variance decomposition of a quantile vector autoregressive model specifically for extreme ***,we control for common movements by using the overall stock market index as a common factor for all sectors and uncover the effect of the COVID-19 outbreak on the dynamics of the *** results show that the network structure and spillovers differ considerably with respect to the market *** stable times,the network shows a nice sectoral clustering structure which,however,changes dramatically for both adverse and beneficial market conditions constituting a highly connected network *** pandemic period itself shows an interesting restructuring of the network as the dominant clusters become more tightly connected while the rest of the network remains well *** sectoral topology thus has not collapsed into a unified market during the pandemic.

关键词： Quantile return spillovers US equity sector indices COVID-19 outbreak Granger causality Global risk aversion

Regime specific spillover across cryptocurrencies and the role of COVID‑19

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Financial Innovation 2021年第1期7卷 91-114页

作者： Syed Jawad Hussain Shahzad elie bouri Sang Hoon Kang Tareq Saeed Montpellier Business School MontpellierFrance South Ural State University ChelyabinskRussian Federation Adnan Kassar School of Business Lebanese American UniversityBeirutLebanon Department of Business Administration Pusan National UniversityBusanSouth Korea Nonlinear Analysis and Applied Mathematics(NAAM)‑Research Group Department of MathematicsFaculty of ScienceKing Abdulaziz UniversityJeddahSaudi Arabia

The aim of this study is to examine the daily return spillover among 18 cryptocurrencies under low and high volatility regimes,while considering three pricing factors and the effect of the COVID-19 *** do so,we apply a Markov regime-switching(MS)vector autoregressive with exogenous variables(VARX)model to a daily dataset from 25-July-2016 to *** results indicate various patterns of spillover in high and low volatility regimes,especially during the COVID-19 *** total spillover index varies with time and abruptly intensifies following the outbreak of COVID-19,especially in the high volatility ***,the network analysis reveals further evidence of much higher spillovers in the high volatility regime during the COVID-19 outbreak,which is consistent with the notion of contagion during stress periods.

关键词： Regime-switching Volatility regimes Spillovers Connectedness Cryptocurrencies COVID-19

Editorial to special issue“Hidden market linkages between Bitcoin,cryptocurrencies and financial markets:Evidence from high‑frequency data and higher‑order moments”in financial innovation

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Financial Innovation 2023年第1期9卷 2904-2907页

作者： elie bouri Syed Jawad Hussain Shahzad Ladislav Kristoufek School of Business Lebanese American UniversityByblosLebanon Montpellier Business School MontpellierFrance Institute of Information Theory and Automation The Czech Academy of SciencesPragueCzech Republic Institute of Economic Studies Faculty of Social SciencesCharles UniversityPragueCzech Republic

The cryptomarket has evolved into a complex system of different types of cryptoassets,each playing an important role within the *** specific features,opportunities,and *** their apparent and hidden linkages and general connectedness not only inside the system but also the linkages to the outer markets,being it either the traditional financial markets or the macroeconomic and monetary indicators and variables,plays a crucial role in understanding the market,managing risks,and aiming for profitable *** cryptomarkets are far from being simply Bitcoin or even just the most popular and capitalised cryptocurrencies and tokens which might have been the case just a few years back.

关键词： financial market assets

ACCURATE ATTENUATION CORRECTION FOR ALGEBRAIC RECONSTRUCTION TECHNIQUE IN SPECT

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Journal of Computational Mathematics 2010年第3期28卷 401-417页

作者： elie Nasr IMB Institute of Mathematics of Bordeaux

We present a new iterative reconstruction algorithm to improve the algebraic reconstruction technique （ART） for the Single-Photon Emission Computed Tomography. Our method is a generalization of the Kaczmarz iterative algorithm for solving linear systems of equations and introduces exact and implicit attenuation correction derived from the attenuated Radon transform operator at each step of the algorithm. The performances of the presented algorithm have been tested upon various numerical experiments in presence of both strongly non-uniform attenuation and incomplete measurements data. We also tested the ability of our algorithm to handle moderate noisy data. Simulation studies demonstrate that the proposed method has a significant improvement in the quality of reconstructed images over ART. Moreover, convergence speed was improved and stability was established, facing noisy data, once we incorporate filtration procedure in our algorithm.

关键词： Single-photon emission computed tomography Attenuated radon transform,Algebraic reconstruction technique Attenuation correction.

Recent advances toward high voltage, EC-free electrolytes for graphite-based Li-ion battery

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Frontiers of Chemical Science and Engineering 2018年第3期12卷 577-591页

作者： Tong Zhang elie Paillard Helmholtz Institute Muenster- Forschungszentrum Juelich (IEK 12) Corrensstr. 46 48149 Muenster Germany

Lithium-ion batteries are a key technology in today＇s world and improving their performances requires, in many cases, the use of cathodes operating above the anodic stability of state-of-the-art electrolytes based on ethylene carbonate （EC） mixtures. EC, however, is a crucial component of electrolytes, due to its excellent ability to allow graphite anode operation-also required for high energy density batteries-by stabilizing the electrode/ electrolyte interface. In the last years, many alternative electrolytes, aiming at allowing high voltage battery operation, have been proposed. However, often, graphite electrode operation is not well demonstrated in these electrolytes. Thus, we review here the high voltage, EC- free alternative electrolytes, focusing on those allowing the steady operation of graphite anodes. This review covers electrolyte compositions, with the widespread use of additives, the change in main lithium salt, the effect of anion （or Li salt） concentration, but also reports on graphite protection strategies, by coatings or artificial solid electrolyte interphase （SEI） or by use of water-soluble binder for electrode processing as these can also enable the use of graphite in electrolytes with suboptimal intrinsic SEI formation ability.

关键词： lithium-ion electrolyte solid electrolyte interphase additives high voltage graphite

Differential effects of glutamate receptor antagonists on dorsal horn neurons responding to colorectal distension in a neonatal colon irritation rat model

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World Journal of Gastroenterology 2005年第41期11卷 6495-6502页

作者： Chun Lin elie D Al-Chaer Laboratory of elie D Al-Chaer(ACELAB) Center for Pain Research (CPR) University of Texas Medical Branch Galveston TX 77555-0632 United States Center for Neubiological Research Department of Physiology and Pathophysiology Fujian Medical UniversityFuzhou 350004 Fujian Province China

AIM: To investigate and compare the effects of spinal D-(-)-2-amino-7-phosphonoheptanoic acid (AP-7) and 6-cyano-7-nitroquinoxaline-2,3-dione disodium (CNQX),two glutamate receptor antagonists, on the responses of dorsal horn neurons to colorectal distension (CRD) in adult rats exposed to neonatal colon irritation (CI).METHODS: Hypersensitive SD rats were generated by CI during postnatal days 8, 10 and 12. Experiments on adult rats were performed using extracellular single-unit recording. The effects of spinal application of AP-7 (0.001,0.01, 0.1, 1 mmoL) were tested on the CRD-evoked neuronal responses in 16 controls and 17 CI rats. The effects of CNQX (0.2, 2, 5, 10 μmoL) were also tested on the CRD-evoked responses of 17 controls and 18 CI ***: (1) The average responses of lumbosacral neurons to all intensities of CRD in CI rats were significantly higher than those in control rats; (2) In control rats, AP-7 (0.01 mmoL) had no significant effect on the neuronal response to all intensities of CRD (20,40, 60, 80 mmHg); while AP-7 (0.1 mmoL) inhibited the neuronal response to 80-mmHg CRD. By contrast, in CI rats, AP-7 (0.01-1 mmoL) attenuated the CRD-evoked neuronal responses to all distention pressures in a dosedependent manner; (3) In control rats, CNQX (2 μmoL)had no significantly effect on the neuronal response to all intensities of CRD; however, CNQX (5 μmoL) significantly attenuated the responses to CRD in the 40-80 mmHg range. By contrast, CNQX (2-10 μmoL)significantly decreased the neuronal responses in CI rats to non-noxious and noxious CRD in a dose-dependent ***: Our results suggest that spinal N-methyl-D-aspartate (NMDA) and non-NMDA receptors may contribute to the processing of central sensitivity in a neonatal CI rat model, but they may play different roles in it.

关键词： Chronic visceral hypersensitivity Dorsal horn neurons Irritable bowel syndrome NMDA receptors Non-NMDA receptors

Cognitive work analysis to comprehend operations and organizations in the mining industry

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International Journal of Mining Science and Technology 2017年第4期27卷 605-609页

作者： Serenay Demir elie Abou-Jaoude Mustafa Kumral Department of Mining and Materials Engineering McGill University Montreal H3A 0E8 Canada

Complex industrial systems, including mining, have a prominent challenge in understanding the interrelationship among the cognitive processes, working environment and available equipment. The concept of cognitive work analysis(CWA) transcends the traditional analytic methods of evaluating human tasks solely based on perceptual and physical traits, and rather implements the notions of behavioral and cognitive awareness indispensable for the intricacy of modern technology. In the last few decades, academic and industrial settings employ this type of analysis to set a suitable standard for a system's safety feasibility, and as a result reduce human-based errors. This research paper analyzes current CWA methods and proposes a five-level quantification model portraying the overall cognitive quality of a mining operation.

关键词： Cognitive work analysis Mining operations Cognitive awareness Work domain Human behavior Safety

An infinite-dimensional representation of the Ray-Knight theorems

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Science China Mathematics 2024年第1期67卷 149-162页

作者： elie Aidékon Yueyun Hu Zhan Shi School of Mathematical Sciences Fudan UniversityShanghai 200433China LAGA UniversitéSorbonne Paris NordVilletaneuse 93430France Institute of Applied Mathematics Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China

The classical Ray-Knight theorems for the Brownian motion determine the law of its local time process either at the first hitting time of a given value a by the local time at the origin,or at the first hitting time of a given position b by the Brownian *** extend these results by describing the local time process jointly for all a and b,by means of the stochastic integral with respect to an appropriate white *** result applies toμ-processes,and has an immediate application:aμ-process is the height process of a Feller continuous-state branching process(CSBP)with immigration(Lambert(2002)),whereas a Feller CSBP with immigration satisfies a stochastic differential equation(SDE)driven by a white noise(Dawson and Li(2012));our result gives an explicit relation between these two descriptions and shows that the SDE in question is a reformulation of Tanaka’s formula.

关键词： Ray-Knight theorem μ-process white noise Tanaka's formula

New trends in colorectal surgery: Single port and natural orifice techniques

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World Journal of Gastroenterology 2014年第48期20卷 18104-18120页

作者： Ronald Daher elie Chouillard Yves Panis Department of General and Digestive Surgery Poissy/Saint-Germain Medical Center 78300Poissy France Department of Colorectal Surgery Beaujon Hospital Assistance Publique Hopitaux de Paris University Denis Diderot (Paris VII) 75013 Clichy France

Single-incision laparoscopic surgery (SILS) and natural orifice transluminal endoscopic surgery (NOTES) have rapidly gained pace worldwide, potentially replacing conventional laparoscopic surgery (CLS) as the preferred colorectal surgery technique. Currently available data mainly consist of retrospective series analyzed in four meta-analyses. Despite conflicting results and lack of an objective comparison, SILS appears to offer cosmetic advantages over CLS. However, due to conflicting results and marked heterogeneity, present data fail to show significant differences in terms of operative time, postoperative morbidity profiles, port-site complications rates, oncological appropriateness, duration of hospitalization or cost when comparing SILS with conventional laparoscopy for colorectal procedures. The application of “pure” NOTES in humans remains limited to case reports because of unresolved issues concerning the ideal access site, distant organ reach, spatial orientation and viscera closure. Alternatively, minilaparoscopy-assisted natural orifice surgery techniques are being developed. The transanal “down-to-up” total mesorectum excision has been derived for transanal endoscopic microsurgery (TEM) and represents the most encouraging NOTES-derived technique. Preliminary experiences demonstrate good oncological and functional short-term outcomes. Large-scale randomized controlled trials are now mandatory to confirm the long-term SILS results and validate transanal TEM for the application of NOTES in humans.

关键词： Surgery Colon Rectum Cancer Laparoscopy Single-port Natural orifice transluminal endoscopic surgery