The Spatial Distribution of Backscattered Electrons Revisited with a New Monte Carlo Simulation

A Monte Carlo simulation program including the discrete energy loss process has been developed, based on the Mott cross section for elastic scattering and the Vriens cross section for inelastic scattering. A deficiency of the previous model which is based on the screened Rutherford cross section and the Bethe law is made clear, from comparison between the new and old results such as the energy distribution of backscattered electrons for a Cu target. With the new Monte Carlo model, the radial spreading and penetration depth of both all and low-loss backscattered electrons have been studied for the Cu target at electron energies of 5.10 and 20 keV. From these studies, it is found that the electron exit angle dependence of the spatial spreading is more significant with the low-loss backscattered electrons and a very high resolution of 2 to 3 nm can be obtained even with backscattered electrons

Value-at-risk in a market subject to regime switching

Many empirical researches report that value-at-risk (VaR) measures understate the actual 1% quantile, while for Inui, K., Kijima, M. and Kitano, A., VaR is subject to a significant positive bias. Stat. Probab. Lett., 2005, 72, 299-311. proved that VaR measures overstate significantly when historical simulation VaR is applied to fat-tail distributions. This paper resolves the puzzle by developing a regime switching model to estimate portfolio VaR. It is shown that our model is able to correct the underestimation problem of risk.VaR, Backtesting, Regime switching, Stochastic volatility, Forecast probability, Smoothed probability, EM algorithm,

Supraglottic NUT Carcinoma: A Case Report and Literature Review

Nuclear protein of the testis (NUT) carcinoma is a very rare cancer that occurs in relatively young patients. In this study, we experienced a case of laryngeal NUT carcinoma that followed a rapid course. A 22-year-old woman was diagnosed with supraglottic squamous cell carcinoma, cT3N2bM0. She underwent chemoradiotherapy (CRT) (total dose, 70 Gy; 2 Gy × 35 Fr; 80 mg/m2 every 3 weeks with CDDP) as a curative treatment and achieved a complete response. However, 3 weeks after the completion of CRT, she presented to the outpatient clinic complaining of abdominal pain. Magnetic resonance imaging revealed a huge neoplastic lesion in the right ovary. Abdominal right adnexal resection plus partial retreatment was performed. The pathology of ovarian tumor was poorly differentiated squamous cell carcinoma, and NUT protein was positive. The laryngeal carcinoma was also positive for NUT protein; therefore, we diagnosed ovarian tumor is metastasis from supraglottic carcinoma. Peritoneal dissemination was observed in the early postoperative period. She was refractory to subsequent chemotherapy and had a rapid progression. Subsequently, CT showed further thickening of the peritoneum, increased ascites, and increased metastases. She died 32 weeks after initial diagnosis and 14 weeks after abdominal surgery. NUT carcinoma is difficult to diagnose without suspicion. Therefore, the possibility of NUT carcinoma should be considered in young patients with laryngeal carcinoma