On a Symmetrization of Diffusion Processes

The latter author, together with collaborators, proposed a numerical scheme to calculate the price of barrier options. The scheme is based on a symmetrization of diffusion process. The present paper aims to give a mathematical credit to the use of the numerical scheme for Heston or SABR type stochastic volatility models. This will be done by showing a fairly general result on the symmetrization (in multi-dimension/multi-reflections). Further applications (to time-inhomogeneous diffusions/ to time dependent boundaries/to curved boundaries) are also discussed

A Numerical Scheme Based on Semi-Static Hedging Strategy

In the present paper, we introduce a numerical scheme for the price of a barrier option when the price of the underlying follows a diffusion process. The numerical scheme is based on an extension of a static hedging formula of barrier options. For getting the static hedging formula, the underlying process needs to have a symmetry. We introduce a way to "symmetrize" a given diffusion process. Then the pricing of a barrier option is reduced to that of plain options under the symmetrized process. To show how our symmetrization scheme works, we will present some numerical results applying (path-independent) Euler-Maruyama approximation to our scheme, comparing them with the path-dependent Euler-Maruyama scheme when the model is of the Black-Scholes, CEV, Heston, and $(\lambda)$-SABR, respectively. The results show the effectiveness of our scheme

Semi-Static Hedging Based on a Generalized Reflection Principle on a Multi Dimensional Brownian Motion

On a multi-assets Black-Scholes economy, we introduce a class of barrier options. In this model we apply a generalized reflection principle in a context of the finite reflection group acting on a Euclidean space to give a valuation formula and the semi-static hedge.Comment: Asia-Pacific Financial Markets, online firs

Disorder of Higher Brain Function in Myotonlc Dystrophy

筋強直性ジストロフィー(以下Mypとする)は第19番染色体長腕にあるMyD原因遺伝子のCTGリピート数の異常増大により発症する常染色体優性遺伝の疾患である。本症では高頻度に中枢神経障害を伴うことが知られており、記憶力や注意力、遂行機能能力、構成能力などの高次脳機能障害がみられる。今回、本症例7例について海馬領域が陳述記憶の中枢として重要であることから頭部MRIで海馬領域の計測を行い、その計測結果と日本語版ウェクスラー記憶検査との比較及び正常コントロール群の計測結果との比較を行った。同時に大脳萎縮についても計測、比較した。さらに知能検査、記憶検査、事象関連電位などとCTGリピート数との関連についも検討した。結論としてMyD群の海馬領域計測では記憶の様式特異性障害が示され、さらに海馬領域を含めた大脳全体の萎縮が示された。また事象関連電位P300とCTGリピートの増大との相関が新たに示された。Myotonic dystrophy (Myp) is an autosomaI dominantly inherited disease. This abnormal gepe for Myp is localized to chromosome 19ql3.3 as an expansion of CTG repeat. There is a correIation between the number of CTG repeats and the severity of clinical symptoms. MyD has been noticed accompanying CNS disorders such as disturbance of memory, attention, executive function and construction. We measured cerebral and hippocampal areas of 7 patients with MyD by MRI Hippocampus is one of important areas of declarative memory, therefore it was examined if there was a correlation between the hippocampaI areas of the patients and the scores of Wechsler Memory Scale-Revised (WMS-R). WechsIer Adult Intelligent Scale-Revised (WAIS-R) and event-related potentia1 P300 were also performed for the patients. Then we anaIyzed a correlation to the number of CTG repeats and each datum. In conclusion, an expansion of CTG repeat was correIated to onset, WMS-R andP300 in the patients. And diffuse brain atrophy was observed and correlated to WAIS-R. Also, the degree of hippocampaI atrophy was significantly correIated to the score of WMS-R, especially verbaI memory tests. It was first found that there was a significant correlation between the latency of P300 and the number of CTG repeats in MyD. These results suggest that CTG expansion and brain atrophy relate to disorder of higher brain function in MyD

Burnout among kindergarten teachers and associated factors

Burnout among kindergarten teachers is a subject of great concern. Although burnout is reported to be significantly associated with turnover intention and work engagement, few studies have examined factors associated with burnout among these teachers. Therefore, in the present study, we performed a cross-sectional survey of burnout and associated factors among kindergarten teachers. We distributed 3363 questionnaires to all 205 authorized kindergartens and childcare institutions in Nagasaki Prefecture and received 1086 responses (response rate: 32.3%). The participants were limited to full-time female class teachers. After excluding survey forms with incomplete content, we ultimately examined valid responses from 442 participants. The survey examined burnout (Maslach Burnout Inventory, MBI), teacher stress (Nursery Teacher’s Stress Scale, NTSS), coping behaviors (Brief Scales for Coping Profile, BSCP), and social support (Social Support Scale, SSS). A multiple regression analysis revealed that all 3 MBI subscales were positively associated with “understanding of how to handle children” on the NTSS and negatively associated with “superiors” on the SSS. “Emotional exhaustion” was significantly associated with “interpersonal relations at work” and “lack of time” on the NTSS, and “avoidance and suppression” on the BSCP. “Depersonalization” was significantly associated with age, “disconnect in working conditions” on the NTSS, and “proactive problem solving” and “venting emotions to others” on the BSCP. “Diminished professional accomplishment” was significantly associated with age, “lack of time” on the NTSS, and “proactive problem solving” and “change in perspective” on the BSCP. These results suggest that support from superiors that enables teachers to better understand children and handle them appropriately is necessary to prevent burnout

Factors associated with kindergarten teachers’ willingness to continue working

The turnover rate among kindergarten teachers in advanced countries is extremely high. As such, there is an urgent need to determine the reasons for this turnover and to identify ways to prevent it. The current study investigates the individual and environmental factors that impact kindergarten teachers’ willingness to continue working.A total of 600 kindergarten teachers in Japan participated in this study. Participants responded to questionnaires regarding their willingness to continue working, mental health, work engagement, and the availability of social support. Multiple logistic regression analysis was used to analyze participants’ data, with willingness to continue working for 5 or more years as the dependent variable. Additionally, Spearman rank correlation was used to examine the correlations between factors associated with willingness to continue working.Factors such as older age, living with a spouse, caring for younger children (up to 2 years old) at work, good mental health, and higher work engagement were significantly associated with teachers’ higher willingness to continue working. Factors such as marriage, health and family problems, overtime work, issues with workplace childcare, and education policy, working time/day problems, human relations, and difficulties taking care of children were correlated with teachers’ lack of willingness to continue working.The findings of this cross-sectional study suggest that welfare benefits and individual support systems could be key elements to encourage kindergarten teachers to continue working and could lead to their improved job satisfaction and mental health. Balanced work conditions and workers’ high agreement with their workplace\u27s overall childcare or educational policies may lead to lower turnover. Some programs – such as relationship counselling – could have a positive impact on teachers’ mental health and job satisfaction