Can Cross-Border Financial Markets Create Endogenously Good Collateral in a Crisis?

In this paper, we explore whether markets can create endogenously good collateral in a crisis by analyzing a simple exchange economy where a country-specific catastrophic shock is shared between two countries. To see this possibility, we examine whether the equilibrium achieved by the time-0 complete markets with solvency constraints can be recovered in the dynamically complete markets with collateral constraints. This paper demonstrates that it is possible to recover the time-0 equilibrium outcome in a sequential manner when pricing errors occur randomly in evaluating Lucas trees at a catastrophic event. Such stochastic components may be interpreted as a policy initiative to create good collateral and yield constrained efficient outcomes at crisis periods.Solvency Constraints, Collateral Constraints, Dynamic Optimal Contract, Catastrophic Shocks

Pulse-Wave Analysis of Optic Nerve Head Circulation Is Significantly Correlated with Kidney Function in Patients with and without Chronic Kidney Disease

Aim. To determine whether there is a significant correlation between the optic nerve head (ONH) circulation determined by laser speckle flowgraphy (LSFG) and kidney function. Materials. Seventy-one subjects were investigated. The estimated glomerular filtration rate (GFR) and serum creatinine, cystatin C, and urinary albumin excretion were measured. The ONH circulation was determined by an analysis of the pulse wave of LSFG, and this parameter was named blowout time (BOT). Chronic kidney disease (CKD) was defined to be present when the estimated GFR was <60 mL/min per 1.73 m2. Pearson’s correlation coefficients were used to determine the relationship between the BOT and the kidney function. We also examined whether there were significant differences in all parameters in patients with and without CKD. Results. BOT was significantly correlated with the level of creatinine (r=-0.24, P=0.04), the estimated GFR (r=0.42, P=0.0003), cystatin C (r=-0.29, P=0.01), and urinary albumin excretion (r=-0.29, P=0.01). The BOT level in subjects with CKD was significantly lower than that in subjects without CKD (P=0.002). Conclusion. BOT in ONH by LSFG can detect the organ damage such as kidney dysfunction, CKD

Relationships among Ocular Blood Flow Shown by Laser Speckle Flowgraphy, Retinal Arteriosclerotic Change, and Chorioretinal Circulation Time Obtained by Fluorescein Angiography

Purpose. To determine the correlations among the mean blur rate (MBR) in the optic nerve head (ONH) shown by laser speckle flowgraphy (LSFG), retinal arteriosclerosis, and the circulation time obtained by fluorescein angiography (FA). Method. We evaluated 118 patients and assessed their time of choroidal flush, arm-to-retina time, and early and late phases of retinal circulation time (RT: sec) obtained by FA. The severity of retinal arteriosclerosis was classified according to the Scheie classification. The MBR values throughout the ONH (MBR-A), in the tissue (MBR-T), and in the vessels (MBR-V) were analyzed. Results. Patients with retinal vein occlusion (RVO) showed prolonged early and late phases of RT compared to other ocular diseases. Single and multiple regression analyses showed that the MBR-V and Scheie classification were significantly associated with both the choroidal flush and arm-to-retina times. The incidences of RVO and MVR-V were significantly associated with the early phase of RT, and the incidences of RVO, MBR-V, Scheie classification, and gender were revealed to be factors independently contributing to the late phase of RT. Conclusion. MBR-V in the ONH and retinal arteriosclerosis are important contributing factors for the circulation time of each stage obtained by FA

Two Cases of Acute Abdomen after an Intravitreal Injection of Bevacizumab

We report on a patient with ischemic colitis and another with paralytic ileus, both of whom experienced an acute abdomen after intravitreal injection of bevacizumab (IVB). Case 1 was a 78-year-old woman. Her medical history included surgery for colon carcinoma 10 years earlier. The patient developed acute severe abdominal pain and nausea the day after IVB for retinal vein occlusion with macular edema, and massive lower gastrointestinal bleeding occurred. Ischemic colitis was diagnosed. Case 2 was a 64-year-old man who presented with neovascular glaucoma with proliferative diabetic retinopathy. We performed vitreous surgery on the 9th day after IVB, and we reperformed IVB at the end of the vitreous surgery. On the first postoperative day, severe abdominal distension, vomiting and abdominal pain were observed, and paralytic ileus was diagnosed. It is possible that gastrointestinal disorders are induced after IVB, depending on the patient's background, including for example severe diabetes or a history of surgery for gastrointestinal cancer. Thus, ophthalmologists should apply alternative therapies instead of IVB to patients with severe diabetes mellitus or a history of gastrointestinal cancer

A Change in Ocular Circulation after Photocoagulation for Retinopathy of Prematurity in a Neonate

Background: The dilation of veins and tortuosity of arteries that occur in retinopathy of prematurity (ROP) are improved by therapy, and thus posttherapy changes in ocular circulation are also conceivable. We report a case of ROP in which we were able to measure the ocular circulation before and after photocoagulation therapy, using a laser speckle flowgraphy (LSFG) system that is modified for neonates. Case Report: A female infant was born at 25 weeks’ gestation with a birth weight of 808 g. We performed photocoagulation in both eyes at age 15 weeks, and we measured the ocular circulation with the “LSFG-baby” system before and at 12 weeks after the photocoagulation treatment. We also measured the mean blur rate (MBR) in the optic nerve head (ONH) and the relative flow volume (RFV) in the retinal vessels, and we examined the change rates from before to after treatment. The changing rate of the MBR-A (the mean of all values) in the ONH in the right and left eyes was 76.5 and 98.5%, respectively. The vascular RFV in the severe dilation and tortuosity quadrant also tended to decrease. Conclusions: Photocoagulation improved the dilation of veins and tortuosity of arteries and reduced the ocular blood flow in this neonate with ROP. The LSFG-baby system effectively and directly revealed the optic nerve and retinal blood vessels

Model-Free Deep Recurrent Q-Network Reinforcement Learning for Quantum Circuit Architectures Design

Artificial intelligence (AI) technology leads to new insights into the manipulation of quantum systems in the Noisy Intermediate-Scale Quantum (NISQ) era. Classical agent-based artificial intelligence algorithms provide a framework for the design or control of quantum systems. Traditional reinforcement learning methods are designed for the Markov Decision Process (MDP) and, hence, have difficulty in dealing with partially observable or quantum observable decision processes. Due to the difficulty of building or inferring a model of a specified quantum system, a model-free-based control approach is more practical and feasible than its counterpart of a model-based approach. In this work, we apply a model-free deep recurrent Q-network (DRQN) reinforcement learning method for qubit-based quantum circuit architecture design problems. This paper is the first attempt to solve the quantum circuit design problem from the recurrent reinforcement learning algorithm, while using discrete policy. Simulation results suggest that our long short-term memory (LSTM)-based DRQN method is able to learn quantum circuits for entangled Bell–Greenberger–Horne–Zeilinger (Bell–GHZ) states. However, since we also observe unstable learning curves in experiments, suggesting that the DRQN could be a promising method for AI-based quantum circuit design application, more investigation on the stability issue would be required

Reproducibility of Neonate Ocular Circulation Measurements Using Laser Speckle Flowgraphy

Measuring the ocular blood flow in neonates may clarify the relationships between eye diseases and ocular circulation abnormalities. However, no method for noninvasively measuring ocular circulation in neonates is established. We used laser speckle flowgraphy (LSFG) modified for neonates to measure their ocular circulation and investigated whether this method is reproducible. During their normal sleep, we studied 16 subjects (adjusted age of 34–48 weeks) whose blood flow could be measured three consecutive times. While the subjects slept in the supine position, three mean blur rate (MBR) values of the optic nerve head (ONH) were obtained: the MBR-A (mean of all values), MBR-V (vessel mean), and MBR-T (tissue mean), and nine blood flow pulse waveform parameters in the ONH were examined. We analyzed the coefficient of variation (COV) and the intraclass correlation coefficient (ICC) for each parameter. The COVs of the MBR values were all ≤10%. The ICCs of the MBR values were all >0.8. Good COVs were observed for the blowout score, blowout time, rising rate, falling rate, and acceleration time index. Although the measurement of ocular circulation in the neonates was difficult, our results exhibited reproducibility, suggesting that this method could be used in clinical research