The Determinants of Domestic and Cross Border Bank Contagion Risk in Southeast Asia

This paper addresses the issue of both domestic and cross border systemic risk for 8 countries in Southeast Asia (Hong Kong, Indonesia, Korea, Malaysia, The Philippines, Singapore, Taiwan and Thailand). We use weekly data on individual bank stock prices from 2000 to 2005 to construct bank contagion measures based on the exponential weighted average correlations of the residuals of the market model. Our results show that average pair-wise correlations significantly differ among countries and that the probability that a specific shock extends to other banks is better explained by asset risk indicators and market based risk measures, such as systematic risk, for cross country contagion. In contrast, for domestic contagion, liquidity risk indicators and bank opaqueness proxies perform better. Our findings suggest that whereas illiquidity, but not insolvency, is a major concern at the domestic level the opposite result holds for cross country contagion.Cet article traite du problème du risque systémique, tant au niveau national que transfrontalier, pour un ensemble de huit pays du Sud-Est asiatique (Hong Kong, Indonésie, Corée, Malaisie, Philippines, Singapour, Taïwan et Thaïlande). On utilise des données hebdomadaires relatives aux cotations boursières de 125 établissements bancaires sur la période 2000-2005 pour construire des mesures du risque de contagion, fondées sur les corrélations moyennes des résidus d'un modèle de marché. Les résultats montrent que ces corrélations moyennes diffèrent significativement d'un pays à l'autre. La probabilité qu'un choc spécifique se propage aux autres établissements au niveau transfrontalier est déterminée par les valeurs prises par des indicateurs du risque de l'actif et du risque de marché (risque systématique). En revanche, au niveau national, les indicateurs du risque d'illiquidité et les mesures d'opacité bancaire ont un meilleur pouvoir explicatif. Nos résultats suggèrent que les opérateurs de marché sont essentiellement influencés par l'illiquidité des banques au niveau national alors qu'ils ne sont sensibles qu'à leur degré d'insolvabilité à l'échelle transfrontalière

Deterministic teleportation using single-photon entanglement as a resource

We outline a proof that teleportation with a single particle is in principle just as reliable as with two particles. We thereby hope to dispel the skepticism surrounding single-photon entanglement as a valid resource in quantum information. A deterministic Bell state analyzer is proposed which uses only classical resources, namely coherent states, a Kerr non-linearity, and a two-level atom.Comment: 6 pages, 4 figure

Electroanalytical study of Prussian Blue modified glassy carbon paste electrodes

Two types of glassy carbon (GC) powder (i.e., Sigradur K and Sigradur G) have been mixed with mineral oil to obtain glassy carbon paste electrodes (GCPE's). The electrochemical behavior of such electrodes at different percentages of glassy carbon has been evaluated with respect to the electrochemistry of ferricyanide as revealed with cyclic voltammetry and the best paste composition was chosen. GC was then modified with Prussian Blue (PB), mixed at different percentages with unmodified GC and with a fixed amount of mineral oil in order to obtain PB modified glassy carbon paste electrodes (PB-GCPE's). PB-GCPE's with different percentages of GC modified with PB (PB-GC) were compared and the dependence on the amount of PB on their performances was evaluated by studying the parameters of cyclic voltammetry (i.e., current peak, Ep, anodic and cathodic current ratio, charge density) and the amperometric response to H2O2. Data interpretation based on the GC surface area is presented. GCPE's with a selected amount of PB-GC were then tested as H2O2 probes and all the analytical parameters together with the dependence on pH were evaluated. Some preliminary experiments with these electrodes assembled as glucose, lysine and lactate biosensors are also reported

First-principles prediction of redox potentials in transition-metal compounds with LDA+U

First-principles calculations within the Local Density Approximation (LDA) or Generalized Gradient Approximation (GGA), though very successful, are known to underestimate redox potentials, such as those at which lithium intercalates in transition metal compounds. We argue that this inaccuracy is related to the lack of cancellation of electron self-interaction errors in LDA/GGA and can be improved by using the DFT+$U$ method with a self-consistent evaluation of the $U$ parameter. We show that, using this approach, the experimental lithium intercalation voltages of a number of transition metal compounds, including the olivine Li$_{x}$MPO$_{4}$ (M=Mn, Fe Co, Ni), layered Li$_{x}$MO$_{2}$ ($x=$Co, Ni) and spinel-like Li$_{x}$M$_{2}$O$_{4}$ (M=Mn, Co), can be reproduced accurately.Comment: 19 pages, 6 figures, Phys. Rev. B 70, 235121 (2004

A Potential Route to Reduce Ischemia/Reperfusion Injury in Organ Preservation

The pathophysiological process of ischemia and reperfusion injury (IRI), an inevitable step in organ transplantation, causes important biochemical and structural changes that can result in serious organ damage. IRI is relevant for early graft dysfunction and graft survival. Today, in a global context of organ shortages, most organs come from extended criteria donors (ECDs), which are more sensitive to IRI. The main objective of organ preservation solutions is to protect against IRI through the application of specific, nonphysiological components, under conditions of no blood or oxygen, and then under conditions of metabolic reduction by hypothermia. The composition of hypothermic solutions includes osmotic and oncotic buffering components, and they are intracellular (rich in potassium) or extracellular (rich in sodium). However, above all, they all contain the same type of components intended to protect against IRI, such as glutathione, adenosine and allopurinol. These components have not changed for more than 30 years, even though our knowledge of IRI, and much of the relevant literature, questions their stability or efficacy. In addition, several pharmacological molecules have been the subjects of preclinical studies to optimize this protection. Among them, trimetazidine, tacrolimus and carvedilol have shown the most benefits. In fact, these drugs are already in clinical use, and it is a question of repositioning them for this novel use, without additional risk. This new strategy of including them would allow us to shift from cold storage solutions to cold preservation solutions including multitarget pharmacological components, offering protection against IRI and thus protecting today's more vulnerable organs

Plasmatic concentration of organochlorine lindane acts as metabolic disruptors in HepG2 liver cell line by inducing mitochondrial disorder.

Lindane (LD) is a persistent environmental pollutant that has been the subject of several toxicological studies. However, concentrations used in most of the reported studies were relatively higher than those found in the blood of the contaminated area residents and effects of low concentrations remain poorly investigated. Moreover, effects on cell metabolism and mitochondrial function of exposure to LD have received little attention. This study was designed to explore the effects of low concentrations of LD on cellular metabolism and mitochondrial function, using the hepatocarcinoma cell line HepG2. Cells were exposed to LD for 24, 48 and 72 h and different parameters linked with mitochondrial regulation and energy metabolism were analyzed. Despite having any impact on cellular viability, exposure to LD at plasmatic concentrations led to an increase of maximal respiratory capacity, complex I activity, intracellular ATP and NO release but decreased uncoupled respiration to ATP synthesis and medium lactate levels. In addition, LD exposure resulted in the upregulation of mitochondrial biogenesis genes. We suggest that, at plasmatic concentrations, LD acts as a metabolic disruptor through impaired mitochondrial function and regulation with an impact on cellular energetic metabolism. In addition, we propose that a cellular assay based on the analysis of mitochondria function, such as described here for LD, may be applicable for larger studies on the effects of low concentrations of xenobiotics, because of the exquisite sensitivity of this organelle

Radiologic Patterns of Necrosis After Proton Therapy of Skull Base Tumors

Background: Discrimination between radiation necrosis and tumor progression after radiation therapy represents a radiologic challenge. The aim of our investigation is to identify patterns of radiation necrosis on brain magnetic resonance imaging (MRI) and positron emission tomography (PET) with Fluoroethyltyrosin (FET) after proton beam therapy (PBT) for skull base tumors. Material and Methods: Five consecutive patients with extra-axial neoplasms were included, presenting a total of eight radiation necrosis lesions (three clival chordomas; two petroclival chondrosarcomas; two women; mean age: 49 ± 18.2 years). Radiation necrosis was defined as the appearance of abnormal enhancement on MRI after PBT decreasing over time, and additional histopathologic confirmation in one patient. MRI and PET imaging were retrospectively analyzed by two experienced radiologists in consensus. Results: All lesions were localized close to the primary tumor in the field of irradiation. Three patients showed bilateral symmetrical lesions. All lesions showed T2 hyperintensity and T1 hypointensity. Cerebral blood volume (CBV) was reduced in all available studies. None of the lesions showed a restricted diffusion. FET-PET (three patients) showed a higher uptake in four out of five lesions; three of which had a mean tumor-to-background (TBRmean) uptake lower than 1.95 and FET uptake increasing over time and were correctly classified into radiation necrosis. Conclusions: Most radiation necroses were in direct continuity with the primary tumor mimicking tumor progression. The most consistent imaging findings for PBT radiation necrosis are low CBV without restricted diffusion and FET-PET TBRmean lower than 1.95 or increasing uptake over time. Bilateral symmetric involvement may be another indicator of radiation necrosi

The FormAI Dataset: Generative AI in Software Security Through the Lens of Formal Verification

This paper presents the FormAI dataset, a large collection of 112, 000 AI-generated compilable and independent C programs with vulnerability classification. We introduce a dynamic zero-shot prompting technique constructed to spawn diverse programs utilizing Large Language Models (LLMs). The dataset is generated by GPT-3.5-turbo and comprises programs with varying levels of complexity. Some programs handle complicated tasks like network management, table games, or encryption, while others deal with simpler tasks like string manipulation. Every program is labeled with the vulnerabilities found within the source code, indicating the type, line number, and vulnerable function name. This is accomplished by employing a formal verification method using the Efficient SMT-based Bounded Model Checker (ESBMC), which uses model checking, abstract interpretation, constraint programming, and satisfiability modulo theories to reason over safety/security properties in programs. This approach definitively detects vulnerabilities and offers a formal model known as a counterexample, thus eliminating the possibility of generating false positive reports. We have associated the identified vulnerabilities with Common Weakness Enumeration (CWE) numbers. We make the source code available for the 112, 000 programs, accompanied by a separate file containing the vulnerabilities detected in each program, making the dataset ideal for training LLMs and machine learning algorithms. Our study unveiled that according to ESBMC, 51.24% of the programs generated by GPT-3.5 contained vulnerabilities, thereby presenting considerable risks to software safety and security.Comment: https://github.com/FormAI-Datase