- 著者
- Yamada H. Nakagaki T. Baker R.E. Maini P.K.
- 出版者
- Springer Berlin / Heidelberg
- 雑誌
- Journal of Mathematical Biology (ISSN:03036812)
- 巻号頁・発行日
- vol.54, no.6, pp.745-760, 2007-06
- 被引用文献数
- 24
In the large amoeboid organism Physarum, biochemical oscillators are spatially distributed throughout the organism and their collective motion exhibits phase waves, which carry physiological signals. The basic nature of this wave behaviour is not well-understood because, to date, an important effect has been neglected, namely, the shuttle streaming of protoplasm which accompanies the biochemical rhythms. Here we study the effects of self-consistent flow on the wave behaviour of oscillatory reaction-diffusion models proposed for the Physarum plasmodium, by means of numerical simulation for the dispersion relation and weakly nonlinear analysis for derivation of the phase equation. We conclude that the flow term is able to increase the speed of phase waves (similar to elongation of wave length). We compare the theoretical consequences with real waves observed in the organism and also point out the physiological roles of these effects on control mechanisms of intracellular communication.
1 0 0 0 OA Zero-suppressed BDDs and their applications
- 著者
- Minato Shin-ichi
- 出版者
- Springer Berlin / Heidelberg
- 雑誌
- International Journal on Software Tools for Technology Transfer (ISSN:14332779)
- 巻号頁・発行日
- vol.3, no.2, pp.156-170, 2001-05
In many real-life problems, we are often faced with manipulating sets of combinations. In this article, we study a special type of ordered binary decision diagram (OBDD), called zero-suppressed BDDs (ZBDDs). This data structure represents sets of combinations more efficiently than using original OBDDs. We discuss the basic data structures and algorithms for manipulating ZBDDs in contrast with the original OBDDs. We also present some practical applications of ZBDDs, such as solving combinatorial problems with unate cube set algebra, logic synthesis methods, Petri net processing, etc. We show that a ZBDD is a useful option in OBDD techniques, suitable for a part of the practical applications.
- 著者
- Nakajima Kenichi Yamasaki Yoshimitsu Kusuoka Hideo Izumi Tohru Kashiwagi Atsunori Kawamori Ryuzo Shimamoto Kazuaki Yamada Nobuhiro Nishimura Tsunehiko
- 出版者
- Springer Berlin / Heidelberg
- 雑誌
- European Journal of Nuclear Medicine and Molecular Imaging (ISSN:16197070)
- 巻号頁・発行日
- vol.36, no.12, pp.2049-2057, 2009-12
- 被引用文献数
- 29
Purpose Diabetic patients have a high risk for cardiovascular events. The role of myocardial perfusion imaging was investigated in asymptomatic diabetic patients to evaluate short-term prognosis in a Japanese population. Methods A total of 506 asymptomatic patients ≥50 years of age who had carotid artery maximum intima-media thickness ≥1.1 mm, urinary albumin excretion of ≥30 mg/g creatinine, with additional criteria of abdominal obesity, low HDL cholesterol, high triglyceride level, and hypertension were enrolled and followed up over a 3-year period. Gated SPECT with stress-rest protocol was performed and analyzed by summed defect scores and QGS software. One-year cardiovascular events were analyzed. Results Myocardial ischemia was observed in 17% of patients, and abnormal perfusion findings of ischemia and/or scar were observed in 32% of patients. By the end of the 1-year follow-up, 33 (6.5%) cardiovascular events occurred including 6 all-cause deaths. Patients with summed stress score (SSS) >8 had a higher incidence of either death or cardiovascular events. Event-free survival rates for SSS 0–3, 4–8, 9–13, and ≥14 were 0.96, 0.95, 0.82, and 0.76, respectively. Multivariate Cox regression analysis showed that significant variables were SSS, history of cerebrovascular accident, and electrocardiographic abnormality at rest. Conclusion The 1-year interim summary showed that cardiovascular events were significantly higher in patients with SPECT abnormality, although hard cardiac event rate was relatively low. Targeted treatment strategy is required for asymptomatic but potentially high-risk diabetic patients.