Statistics of seismic cluster durations

Using the standard ETAS model of triggered seismicity, we present a rigorous theoretical analysis of the main statistical properties of temporal clusters, defined as the group of events triggered by a given main shock of fixed magnitude m that occurred at the origin of time, at times larger than some present time t. Using the technology of generating probability function (GPF), we derive the explicit expressions for the GPF of the number of future offsprings in a given temporal seismic cluster, defining, in particular, the statistics of the cluster's duration and the cluster's offsprings maximal magnitudes. We find the remarkable result that the magnitude difference between the largest and second largest event in the future temporal cluster is distributed according to the regular Gutenberg-Richer law that controls the unconditional distribution of earthquake magnitudes. For earthquakes obeying the Omori-Utsu law for the distribution of waiting times between triggering and triggered events, we show that the distribution of the durations of temporal clusters of events of magnitudes above some detection threshold \nu has a power law tail that is fatter in the non-critical regime $n<1$ than in the critical case n=1. This paradoxical behavior can be rationalised from the fact that generations of all orders cascade very fast in the critical regime and accelerate the temporal decay of the cluster dynamics.Comment: 45 pages, 15 figure

重い電子系化合物 CeRu2Si2 の超低温高磁場における熱膨張・磁歪に関する研究

13301甲第4397号博士(理学)金沢大学博士論文要旨Abstract 掲載予定あ

重い電子系化合物 CeRu2Si2 の超低温高磁場における熱膨張・磁歪に関する研究

13301甲第4397号博士(理学)金沢大学博士論文本文Full 掲載予定あ

A new method of hip joint moment’s evaluation

Joint moments play very important role in biomechanical research related to lower limbs. Three–dimensional motion analysis is widely used in clinical decision making and sport biomechanics. The accuracy of joint moments is particularly important for data analysis. If the joint moments are not accurate, it will mislead the clinical judgment. However there is no method to verify the accuracy of joint moments. To assess the reliability of the joint moments, a new method should be developed. So a new method based on the principle of the transfer between mechanical lower limb work and potential energy was developed. Five healthy student volunteers participated in the study. The motion data were collected and were processed using VICON motion analysis system. The lower limb work and the potential energy were calculated and compared in four kinds of hip joint centre location estimation models. Using the new concept, one of the four models showed the least difference between the potential energy increase and mechanical work. With this concept, the model in which the most accurate joint moment can be calculated was identified. However, given that these techniques are commonly used in the motion analysis laboratory set by researchers and clinicians, more investigations are needed in order to upgrade laboratory setting and joint center prediction methods

The plant-derived triterpenoid, cucurbitacin B, but not cucurbitacin E, inhibits the developmental transition associated with ecdysone biosynthesis in Drosophila melanogaster

In insects, some sterols are essential not only for cell membrane homeostasis, but for biosynthesis of the steroid hormone ecdysone. Dietary sterols are required for insect development because insects cannot synthesize sterols de novo. Therefore, sterol-like compounds that can compete with essential sterols are good candidates for insect growth regulators. In this study, we investigated the effects of the plant-derived triterpenoids, cucurbitacin B and E (CucB and CucE) on the development of the fruit fly, Drosophila melanogaster. To reduce the effects of supply with an excess of sterols contained in food, we reared D. melanogaster larvae on low sterol food (LSF) with or without cucurbitacins. Most larvae raised on LSF without supplementation or with CucE died at the second or third larval instar (L2 or L3) stages, whereas CucB-administered larvae mostly died without molting. The developmental arrest caused by CucB was partially rescued by ecdysone supplementation. Furthermore, we examined the effects of CucB on larval-prepupal transition by transferring larvae from LSF supplemented with cholesterol to that with CucB just after the L2/L3 molt. L3 larvae raised on LSF with CucB failed to pupariate, with a remarkable developmental delay. Ecdysone supplementation rescued the developmental delay but did not rescue the pupariation defect. Furthermore, we cultured the steroidogenic organ, the prothoracic gland (PG) of the silkworm Bombyx mori, with or without cucurbitacin. Ecdysone production in the PG was reduced by incubation with CucB, but not with CucE. These results suggest that CucB acts not only as an antagonist of the ecdysone receptor as previously reported, but also acts as an inhibitor of ecdysone biosynthesis

南大洋インド洋区季節海氷域における溶存炭酸物質の季節変化

第6回極域科学シンポジウム分野横断セッション：[IB1] 海氷域における生物地球化学的研究11月17日（火）　統計数理研究所 セミナー室1（D305

Ambient fine and coarse particles in Japan affect nasal and bronchial epithelial cells differently and elicit varying immune response

Ambient particulate matter (PM) epidemiologically exacerbates respiratory and immune health, including allergic rhinitis (AR) and bronchial asthma (BA). Although fine and coarse particles can affect respiratory tract, the differences in their effects on the upper and lower respiratory tract and immune system, their underlying mechanism, and the components responsible for the adverse health effects have not been yet completely elucidated. In this study, ambient fine and coarse particles were collected at three different locations in Japan by cyclone technique. Both particles collected at all locations decreased the viability of nasal epithelial cells and antigen presenting cells (APCs), increased the production of IL-6, IL-8, and IL-1β from bronchial epithelial cells and APCs, and induced expression of dendritic and epithelial cell (DEC) 205 on APCs. Differences in inflammatory responses, but not in cytotoxicity, were shown between both particles, and among three locations. Some components such as Ti, Co, Zn, Pb, As, OC (organic carbon) and EC (elemental carbon) showed significant correlations to inflammatory responses or cytotoxicity. These results suggest that ambient fine and coarse particles differently affect nasal and bronchial epithelial cells and immune response, which may depend on particles size diameter, chemical composition and source related particles types

Thermal Expansion and Magnetostriction of Heavy Fermion CeRu2Si2 at Millikelvin Temperatures

金沢大学理工研究域数物科学系We have measured linear thermal expansion and magnetostriction of single crystal CeRu2Si2 that is well known as a heavy fermion metamagnetic compound. Thermal expansion and magnetostriction along the a-axis (B | a) and the c-axis (B | c) were measured by the capacitive dilatometer at temperatures down to 12 mK and in magnetic fields up to 9 T. We observed a strong anisotropy between a and c axis. In addition, negative deviations from Landau-Fermi liquid behavior for thermal expansion and magnetostriction coefficients were found below 50 mK and 0.4 T indicating non Fermi liquid behavior. © 2015 The Authors. Published by Elsevier B.V.出版社