A New Framework for Measuring the Credit Risk of a Portfolio: The "ExVaR" Model

This paper proposes a new framework for the quantitative evaluation of the credit risk of a portfolio by extending the concept of value at risk. In practice, the risk evaluation period is set individually for each transaction in the portfolio and a simulation is carried out on the movements of default probabilities, interest rates, and collateral asset prices as well as on the realization of defaults of counter parties. The result fixes the cash flow along the simulated path and leads to the present value of the total cash flows. By repeating this procedure many times, we obtain the probability distribution of the present value, by which we can evaluate the price and the risk of the portfolio. This framework enables us comprehensively and objectively to measure the risk taking into account the diversification/concentration effect, the collateral effect, and the correlation between credit risk factors and market risk factors. After presenting the methodology, the paper calculates the risk of hypothetical test portfolios. They are used to discuss the applicability of the framework to practical uses.

Role of hydrophobic interaction in hapten-antibody binding

The precipitation reaction of bovine serum albumin coupled with p-azophenylleucine with homologous antibody was inhibited by several structurally related haptens. The isobutyl group substituent on alpha-carbon atom of the leucine residue contributed more than -5.8 Kcal/mol to the free energy of binding. This value was consistent with the free energy change expected from the transfer of n-butane from an aqueous environment to liquid n-butane. The observed contribution was explained, in terms of the hydrophobic interaction of the isobutyl group with the antigen binding site of the antibody molecule. These results were also compared with other hapten-antibody systems.</p

Co-integration of Silicon Nanodevices and NEMS for Advanced Information Processing (Invited Talk)

In this paper we present our recent attempts at developing the advanced information processing devices by integrating nano-electro-mechanical (NEM)structures into conventional silicon nanodevices. Firstly, we show high-speed and nonvolatile NEM memory which features a mechanically-bistable floating gate is integrated onto MOSFETs. Secondly we discuss hybrid systems of single-electron transistors and NEM structures for exploring new switching principles

The Diffusion of Sodium Ions into Tin Oxide Thin Films from Glass Substrates

Electrical resistance and X-ray photoelectron depth profile analysis are studied for antimony doped tin oxide films developed on silica, alkali-free and sodalime slide glass substrates. The sodium ions diffused from the substrates to the films prevented the crystal growth of rutile type tin oxide in the film, resulting in the high electrical resistance. A diffusion layer has been detected for each film with diffuse profiles of multi valent cations (Sn, Si or Ca) at the interface of the tin oxide film and substrate. A greater amount of sodium atoms have been detected in the film developed on the soda-lime glass while almost no sodium atoms have been found in those on the other substrates. This can be explained by the diffusion of the sodium ions in the substrate due to a drastic hydronium-sodium exchange mechanism under highly acidic conditions during the dipping and drying processes

Suramin prevents the development of diabetic kidney disease by inhibiting NLRP3 inflammasome activation in KK-Ay mice

Aims/Introduction Nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasomes produce IL-18 upon being activated by various stimuli via the P2 receptors. Previously, we showed that serum and urine IL-18 levels are positively associated with albuminuria in patients with type 2 diabetes, indicating the involvement of inflammasome activation in the pathogenesis of diabetic kidney disease (DKD). In the present study, we investigated whether the administration of suramin, a nonselective antagonist of the P2 receptors, protects diabetic KK.Cg-A(y)/TaJcl (KK-Ay) mice against DKD progression. Materials and Methods Suramin or saline was administered i.p. to KK-Ay and C57BL/6J mice once every 2 weeks for a period of 8 weeks. Mouse mesangial cells (MMCs) were stimulated with ATP in the presence or absence of suramin. Results Suramin treatment significantly suppressed the increase in the urinary albumin-to-creatinine ratio, glomerular hypertrophy, mesangial matrix expansion, and glomerular fibrosis in KK-Ay mice. Suramin also suppressed the upregulation of NLRP3 inflammasome-related genes and proteins in the renal cortex of KK-Ay mice. P2X4 and P2X7 receptors were significantly upregulated in the isolated glomeruli of KK-Ay mice and mainly distributed in the glomerular mesangial cells of KK-Ay mice. Although neither ATP nor suramin affected NLRP3 expression in MMCs, suramin inhibited ATP-induced NLRP3 complex formation and the downstream expression of caspase-1 and IL-18 in MMCs. Conclusions These results suggest that the NLRP3 inflammasome is activated in a diabetic kidney and that inhibition of the NLRP3 inflammasome with suramin protects against the progression of early stage DKD

Association between high cardiac output at altitude and acute mountain sickness: preliminary study on Mt. Fuji

Background: Acute mountain sickness (AMS) affects around 30% of people climbing Mt. Fuji, but its pathogenesis is incompletely understood. The influence of a rapid ascent to high altitude by climbing and summiting Mt. Fuji on cardiac function in the general population is unknown, and its association with altitude sickness has not been clarified. Methods: Subjects climbing Mt. Fuji were included. Heart rate, oxygen saturation, systolic blood pressure, cardiac index (CI) and stroke volume index were measured multiple times at 120 m as baseline values and at Mt. Fuji Research Station (MFRS) at 3,775 m. Each value and its difference from the baseline value (Δ) of subjects with AMS (defined as Lake Louise Score [LLS] ≥ 3 with headache after sleeping at 3,775 m) were compared with those of non-AMS subjects. Results: Eleven volunteers who climbed from 2,380 m to MFRS within 8 h and stayed overnight at MFRS were included. Four suffered AMS. Compared with the non-AMS subjects, CI in the AMS subjects was significantly higher than that before sleeping (median [interquartile range]: 4.9 [4.5, 5.0] vs. 3.8 [3.4, 3.9] mL/min/m2; p = 0.04), and their ΔCI was significantly higher before sleeping (1.6 [1.4, 2.1] vs. 0.2 [0.0, 0.7] mL/min/m2; p < 0.01) and after sleeping (0.7 [0.3, 1.7] vs. -0.2 [-0.5, 0.0] mL/min/m2; p < 0.01). ΔCI in the AMS subjects dropped significantly after sleeping versus before sleeping (3.8 [3.6, 4.5] vs. 4.9 [4.5, 5.0] mL/min/m2; p = 0.04). Conclusions: Higher values of CI and ΔCI were observed at high altitude in the AMS subjects. A high cardiac output might be associated with the development of AMS.Ebihara T., Shimizu K., Mitsuyama Y., et al. Association between high cardiac output at altitude and acute mountain sickness: preliminary study on Mt. Fuji. Journal of Physiological Anthropology 42, 6 (2023); https://doi.org/10.1186/s40101-023-00322-7