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Modeling the postmortem liver for autopsy imaging is a challenging problem owing to the variation in organ deformation found in cadavers and limited availability of postmortem liver CT scans. An algorithm was developed to construct a statistical shape model (SSM) for the adult postmortem liver in autopsy imaging.First, we investigated the relationship between SSMs obtained from in vivo liver CT scans and those from postmortem cases. Liver shapes were embedded in level set functions and statistically modeled using a spatially weighted principal components analysis. The performance of the SSMs was evaluated in terms of generalization and specificity. Several algorithms for the transformation from in vivo livers to postmortem livers were proposed to enhance the performance of an SSM for a postmortem liver, followed by a comparative study on SSMs. Specifically, five SSMs for a postmortem liver were constructed and evaluated using 32 postmortem liver labels, and postmortem liver labels synthesized from 144 in vivo liver labels were constructed using the proposed transformation algorithms. We also compared the proposed SSMs with three conventional SSMs trained from postmortem liver labels and/or in vivo liver labels.The investigation showed that the performance of an SSM constructed using in vivo liver labels suffered when describing postmortem liver shapes. Two of the five proposed SSMs trained using synthesized postmortem livers showed the best performance with no significant differences between them, and they statistically outperformed all conventional SSMs tested.The performance of conventional SSMs can be improved by using both postmortem liver shape labels and artificial shape labels synthesized from in vivo liver shape labels.

A time-dependent model for magma intrusion associated with repeated earthquake swarm activities off the east coast of the Izu peninsula was developed from precise levelling, electronic distance measurements (EDM) and global positioning system (GPS), and sea level observation data for the period 1973–1998. Significant deformations were observed in the inter-swarm period, suggesting the existence of a preparatory process for repeated earthquake swarm events. The geometry of a dyke-like tensile crack at a depth of 13 km from deformation detected was estimated by precise levelling and GPS for the inter-swarm period, using a genetic algorithm. A large crack plane was considered; it had a combination of estimated deep tensile crack with a shallow dyke detected using the hypocentre distribution and calculated time-dependent inversion, which was carried out to estimate the temporal changes in the volumes of the crack in the period 1973–1998. Akaike's Bayesian information criterion (ABIC) was used to choose the smoothing hyperparameters for the inversion. The characteristics of the estimated temporal change in magma volume were as follows. A rapid and large magma intrusion occurred at a depth of about 15 km between 1976 and 1977. Despite a decrease in its expansion rate, a tensile crack at a depth greater than 8 km continued to inflate between 1978 and 1988. The swarm activity started just one year after the rapid and large intrusion around the 15 km depth. In addition, the tensile crack at the depth of about 15 km beneath the internal region of the eastern Izu peninsula expanded in the inter-swarm period and deflated in the swarm period. This result suggests that magma was temporarily reserved in a dyke-like body beneath the eastern part of the Izu peninsula at a depth of 15 km in a preparatory process for the earthquake swarm. These features strongly show that estimating the spatio-temporal distribution of this deep crack provides useful information for long-range predictions of volcanic earthquake swarms off the east coast of the Izu peninsula.

We present a novel application of cosmic-ray muon radiography to image the shallow density structure beneath Asama Volcano, Japan. We use a single detector (emulsion cloud chamber) set up in an underground vault at an elevation of 2250 m on the eastern flank of Asama, 310 m below the summit of the edifice and 1 km away from the crater. The results point to two high-density anomalies located between the original pre-2004 eruption crater floor and post-2004 eruption crater profile. A third low-density anomaly is imaged immediately below the pre-2004 eruption crater floor. The spatial extent of each density anomaly is about 100 to 200 m. To know if this method, applied to other volcanoes, would produce contrasting results, we performed the measurement in 1944 Usu lava dome. We confirmed a bulbous shape measuring approximately 300 m in diameter and narrowing downwards. The diameter of the uppermost part of the conduit is estimated at 100 ± 15 m at an elevation of 260 m a.s.l. and 50 ± 15 m at an elevation of 217 m a.s.l., demonstrating a resolution that is significantly better than that typically achieved with seismic tomography based on picks of first arrival times from earthquakes or artificial sources.

A time-dependent model for volume changes in pressure sources at Asama volcano is developed from precise leveling data collected since 1902. The optimal source model is determined by comparing five different models (a model with three types of spherical sources, single dike, and dike with a spherical source) during three periods: 1935 to 1939, 1939 to 1950/1953, and 1990 to November 2004. The optimal parameters for each model are estimated by employing a genetic algorithm (GA). The model with two spherical sources was selected as the optimal model. In this model, one of the sources was estimated to be located at a depth of approximately 6 km beneath Kurofu volcano; the other source was estimated to be located close to Maekake volcano at a depth of approximately 2 km. The volume changes in the two spherical sources are calculated using the Akaike's Bayesian information criterion (ABIC) for the period from 1902 to 2005. During the period from 1902 to 1943, a large inflation was estimated in a source at a depth of approximately 6 km beneath Kurofu volcano, which is an older volcano at the base of Asama. After 1943, a rapid deflation continued until 1967. This rapid deflation changed to a marginal inflation that continued from 1967 until 2005. The temporal change in the pressure source beneath Kurofu volcano exhibits a strong positive correlation with the eruption frequency. The leveling data does not suggest a significant volume change in the source beneath Kurofu volcano during the quiet period between 1962 and 2005. During the 20th century, magma appears to have been episodically supplied beneath Asama volcano. In particular, the inflation of the source beneath Kurofu volcano, and probably the magma supply, reached a peak from 1930 to 1940.

A time-dependent model of magma intrusion is presented for the Miyake–Kozu Island area in central Japan based on global positioning system (GPS) measurements at 28 sites recorded between June 27 and August 27, 2000. A model derived from a precise hypocenter distribution map indicates the presence of three dikes between Miyake and Kozu Islands. Other dike intrusion models, including a dike with aseismic creep and a dike associated with a deep deflation source are also discussed. The optimal parameters for each model are estimated using a genetic algorithm (GA) approach. Using Akaike's information criteria (AIC), the three-dike model is shown to provide the best solution for the observed deformation. Volume changes in spherical inflation and deflation sources, as well as three dikes, are calculated for seven discretized periods after GA optimization of the dike geometry. The optimization suggests a concentration of dike expansion near Miyake Island in the period from June 27 to July 1 associated with large deflation at a depth of about 7 km below Miyake volcano, indicating magma supply from depth below Miyake Island. In the period from July 9 to August 10, a huge dike intrusion near Kozu Island is inferred, accompanied by expansion of the lower parts of a central dike, suggesting magma supply from depth in the region between Miyake and Kozu Islands.

Employing both absolute and relative gravimeters, we carried out a hybrid microgravity survey at Miyakejima volcano, Japan. We detected significant gravity changes, e.g., exceeding 1000 At gal, during the course of our measurements since June 1998. The spatio-temporal gravity changes provide us with strong evidence of preexisting vacant space beneath the island before the summit collapse of the volcano. Also, our data are totally in conflict with the so-called magma drainback model, suggesting that the magma flowed out laterally.

This paper proposes a relaxed conditional hierarchical statistical shape model (SSM) of multiple organs. After extracting shape and pose parameters from the training label dataset of multiple organs, the shape model and the pose model of each organ are constructed by principal component analysis (PCA). Subsequently, the principal scores of all organs are concatenated into a vector, and the vectors computed from the training dataset are forwarded to the PCA-based statistical modeling of the multiple organs under conditions of their neighboring organs. A relaxation scheme is introduced, to take into account errors in the conditions. This study focuses on modeling of a spleen and a gallbladder given a liver as a conditional organ. The performance of the model was evaluated with the measures of generalization and specificity, which were computed by three-fold cross-validation using labels of 27 abdominal CT volumes with the size of 170 × 170 × 110 voxels and a resolution of 1.8809 mm/voxel. Compared with a hierarchical SSM without conditions, generalization and specificity were improved from 0.488 to 0.506 and from 0.319 to 0.328 on average, respectively. In addition, the proposed relaxed conditional hierarchical SSM outperformed a hierarchical SSM with hard conditions. The performance indices were improved by 0.040 and 0.010 for generalization and specificity, respectively.

Excitonic luminescence from ZnS epitaxial layers has been studied under magnetic fields up to 9 T in Faraday configuration. The luminescence line due to the radiative recombination of light-hole free excitons slightly shifted to the lower-energy side (about 0.3 meV at 9 T). On the other hand, the luminescence line due to the radiative recombination of biexcitons split into two components. This splitting (about 1.2 meV at 9 T) originated from the Zeeman splitting of light-hole free excitons in the final state of the optical transition for biexciton luminescence.

Characteristics of biexcitons in ZnS epitaxial layers with biaxial tensile strain have comprehensively been studied by means of photoluminescence excitation spectroscopy, magnetophotoluminescence spectroscopy, and time-resolved photoluminescence spectroscopy. Photoluminescence excitation measurement of biexcitons allowed us to observe two-photon absorption of biexcitons and to determine the biexciton binding energy of $8.0\ifmmode\pm\else\textpm\fi{}1.2\mathrm{meV}.$ Under a magnetic field, the luminescence line due to the radiative recombination of light-hole free excitons slightly shifted to the lower-energy side (about 0.3 meV at 9 T). On the other hand, the luminescence line due to the radiative recombination of biexcitons split into two components. This splitting (about 1.2 meV at 9 T) originated from the Zeeman splitting of light-hole free excitons in the final state of the optical transition for biexciton luminescence. In addition, the luminescence decay times of both light-hole free excitons and biexcitons were estimated to be about 130 and 80 ps, respectively. The observed temporal behavior was consistent with the expected recombination dynamics between excitons and biexcitons.

Basalt magma sometimes moves through volcanic conduits causing only minor deformation. In that case, we may detect magma movements directly by microgravity observations. After the 1986 eruption of Izu-Oshima volcano, we observed anomalous gravity variations localized at the summit. Based on a vertical cylindrical conduit model, we estimate the time variations of the head of magma in the summit conduit and clarify the magma drain-back process after the 1986 eruption.

Two-photon absorption processes of biexcitons in ZnS-based quantum-well structures have been studied by means of photoluminescence excitation spectroscopy. The peak position of two-photon absorption of biexcitons was dependent on the detected energy position in the photoluminescence excitation measurement. The energy difference between the one-photon exciton resonance and the two-photon biexciton resonance increased as the detected energy position was moved towards the lower-energy side of the biexciton luminescence. This result indicated the biexciton localization and the resultant increase in the biexciton binding energy.

Complexation of dimethyl penta-2,3-dienedioates to tris[(R)-(1R*)-3-(2,2,3,3,4,4,4-heptafluoro-1-oxobutyl)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-onato-O,O‘]europium, (+)-Eu(hfc)3, enriched the (S)-isomer with high enantioselectivity. When a more bulky ester was used, although the enantioselectivity increased to >95% ee, considerable decomposition occurred. Among the available lanthanide shift reagents, only the europium reagent is effective in this transformation. The reaction involves interconversion of diastereomeric complexes, with enrichment of the preferred one. However, the observed decrease in the 1H NMR peaks might suggest that subsequent reconstruction or reordering the higher-order complex may occur in the reaction solution.

This paper proposes a novel conditional statistical shape model (SSM) that allows a relaxed conditional term. The method is based on the selection formula and allows a seamless transition between the non-conditional SSM and the conventional conditional SSM. Unlike a conventional conditional SSM, the relaxed conditional SSM can take the reliability of the condition into account. Organ shapes estimated by the proposed SSM were used as shape priors for Graph Cut based segmentation. Results for liver shape estimation and subsequent liver segmentation show the benefit of the proposed model over conventional conditional SSMs.

We propose a new type of deformed map where both the close and the distant view are expressible.

Highly enantioselective deracemization route of chiral 2,3-pentadienedioates was achieved by complexation with the chiral organoeuropium reagent.

[1] We developed a radiographic technique to image a subsurface conduit shape using cosmic-ray muons. The test measurement was performed in Showa-Shinzan lava dome located in Hokkaido, Japan as an example. A muon detector with an area of 6000 cm2 was set up at the foot of the lava dome. Muon tracks recorded in nuclear emulsion films in the detector were analyzed to determine the level of energy absorption along different ray paths through subsurface beneath the lava dome. A typical angular resolution of the muon detector of 10 mrad corresponds to a spatial resolution of 10 m at a distance of 1 km, which is difficult to be addressed with seismological technique. We mapped differentially absorbed cosmic-ray muons, which depend upon the varying thickness and density beneath the dome. We successfully imaged the conduit shape and determined a conduit diameter of 102 ± 15 m, assuming the observed high absorption region beneath the dome is localized in the vent area.

[1] We present the three-dimensional structures of the P wave velocity (VP), S wave velocity (VS) as well as the P wave to S wave velocity ratio (VP/VS) beneath Mount Fuji and the South Fossa Magna, Japan, using arrival time data collected from 2002 to 2005 by a dense seismograph array. The high-resolution data set and improved methodology reveal not only several velocity features that are consistent with previous studies but also important new details that clarify the velocity structures associated with volcanic processes beneath Mount Fuji and the collision tectonics of the South Fossa Magna. One such particular feature is a low-VP, low-VS and low-VP/VS anomaly at depths of 7–17 km beneath Mount Fuji that corresponds with the locations of deep low-frequency (DLF) earthquakes. The coincidence of the velocity anomaly and the DLF locations suggests that supercritical volatile fluid, such as H2O and CO2, may be abundant in the low-VP/VS region and may play an important role in generating DLF earthquakes. This anomaly overlies a deeper low-VP, low-VS and high-VP/VS anomaly at depths of 15–25 km that may represent a zone of basaltic partial melt. A low-VP, low-VS and low-VP/VS anomaly is seen at depths of 6–14 km beneath Mount Hakone. Isovelocity surfaces (VP = 6.0 km/s and VS = 3.5 km/s) corresponding to the upper limit of hypocenter distribution below Mount Fuji may define the upper surface of the Philippine Sea plate whose existence in a seismic gap beneath Mount Fuji has been controversial.

[1] Calderas are ubiquitous topographic features of volcanos, yet caldera formation itself has not been recorded intensively by modern measurement techniques. Here we report the spatiotemporal gravity changes before and after caldera collapse at the Miyakejima volcano, Japan in 2000. A gravity decrease of as much as 145 μGal (1 μGal = 10−8 m/s2) at the summit area since June 1998 was detected 2 days prior to the collapse, interpreted as reflecting the formation of a large void beneath the volcano. Gravity changes detected after the initiation of collapse can mostly be corrected by the effect of collapsed topography, from which a rapid rate of collapse of more than 1.6 × 107 m3/d can be inferred. Correcting for the effect of topography change, we identified a temporal decrease in gravity from the middle of July to late August despite ground subsidence. The gravity decrease is interpreted as a reduction of the density in a cylindrical conduit, attributed to water inflow from an ambient aquifer that also promoted intensive magma-water interaction and subsequent explosive eruptions. From September to at least November 2000, gravity values at all sites increased significantly by a degree that cannot be explained by ground displacement alone. We interpret this temporal evolution as primarily due to magma ascent and refilling of the conduit.

Seismic experiments were conducted on Showa-Shinzan, a parasitic lava dome of volcano Usu, Hokkaido, which was formed during 1943–1945 activity. Since we found that firework shots fired on the ground can effectively produce seismic waves, we placed many seismometers on and around the dome during the summer festivals in 1984 and 1985. The internal structure had been previously studied using a prospecting technique employing dynamite blasts in 1954. The measured interval velocity across the dome in 1984 ranges 1.8–2.2 km/s drastically low compared to the results (3.0–4.0 km/s) in 1954; in addition, the velocity is 0.3–0.5 km/s higher than that in the surrounding area. The variation of the observed first arrival amplitudes can be explained by geometrical spreading in the high velocity lava dome. These observations show a marked change in the internal physical state of the dome corresponding to a drop in the measured highest temperature at fumaroles on the dome from 800°C in 1947 to 310°C in 1986.

An earthquake swarm, and the major pumice eruptions in August 1977 which followed, marked the start of the dacitic doming activity of Usu volcano in southwestern Hokkaido, Japan. The sequence of magma intrusion processes was investigated in detail by means of seismological and other geophysical data. The distribution of the abundant hypocenters shows clearly an earthquake-free zone beneath the summit crater. The hypocenters migrated in a manner consistent with the development of the observed asymmetrical surface deformations, considered due to magma intrusion into this earthquake-free zone. The earthquake mechanism solutions are mostly of dip-slip type and are interpreted in terms of the doming deformations. The existence of earthquake families (earthquakes with similar waveforms) is the main cause of the peculiar occurrence of earthquakes in space, time and magnitude. The concept of scattered barriers of different sizes and strengths can explain well the distinct characteristics of the occurrence of the swarm, and the observed episodic deformations.

The 1977–1978 activity of Usu volcano was characterized by persistent earthquake swarms and remarkable ground deformations, which continued until March 1982. Essential evidence for considering the cause of the long-lived activity is that the rate of seismic energy release and the upheaval rate of the new cryptodome decreased exponentially after the pumice eruptions in August 1977. Associated with the phreatomagmatic eruptions in August–September 1978, other valuable evidences were observed; co-eruptive deflation of the summit and post-eruption quiescence of the seismic activity and ground deformations. These observational evidences suggest that a possible cause of the long-lived activity might be the gradual bubble growth in the dacite magma which had been isolated from deeper sources, but partly supersaturated with volatiles even after the pumice eruptions. Numerical calculations based on a bubble growth model indicated that the observed time-variations of the upheaval rate of the cryptodome could be well explained by the model, if the water diffusivity in the dacite magma of Usu volcano were of the order of 10−9 cm2 s−1 and the degree of supersaturation had been a few percent after the pumice eruptions in August 1977.

A simple relation holds between the gravity and elevation changes associated with a fissure eruption. If combined with inversion schemes, it enables us to estimate the location and geometry of the subsurface fractured area. We applied the technique to the 1986 eruption of the Izu-Oshima volcano, Japan, where a textbook-like fissure eruption was observed.

By means of the viscosimetric method, the inhibitory effect of E-A.C.A. on plasmin caseinolysis was studied.(1) e-A. C. A. inhibits competitively S. K.-activation process of human plasminogen.(2) a) At high concentrations, over 2%, e-A. C. A. inhibits noncompetitively caseinolytic activity of plasmin produced from human globulin with S. K.b) At low concentrations, below 1%, it enhances caseinolytic activity of plasmin.This enhancing effect was not seen when e-A.C.A. was added to casein before the latter was affected by plasmin. (Fig. 6)I should like to thank the members of the Technical Center of the ResearchProject on Plasmin and Antiplasmin and Prof. S. Okamoto.

We have developed a method for three-dimensional simultaneous velocity and density inversion using traveltimes of local earthquakes and gravity data. The purpose of this method is to constrain the velocity inversion and increase the spatial resolution of shallow velocity structures by introducing additional gravity data. The gravity data contributes to the P- and S-wave velocity models by imposing constraints between seismic velocities and density. The constraint curve is constructed so as to fit the data for porous rock samples, and deviations from the curve are taken into account in the inversion. The constraint is imposed at only the first layer, because density structure is well resolved at shallower parts and it is difficult to determine uniquely at greater depths. Synthetic inversion tests indicate that gravity data can improve the resolution of the velocity models for this layer. The method is applied to investigate the subsurface structure of Izu-Oshima volcano, Japan and velocity structures with high spatial resolution are obtained. The additional gravity data contribute primarily to improvement of the S-wave velocity model. At 0.25 km depth, a high velocity anomaly due to caldera-filling lava flows is observed. At 1.25 and 2.5 km depths, high velocity intrusive bodies are detected. A NW-SE trending high velocity belt at 1.25 km depth is interpreted as being caused by repeated intrusion of dikes.

Observed seismic waveforms were analyzed to find the distribution of seismic scatterers beneath Izu-Oshima volcano in an island located about 100 km south of Tokyo, Japan, using seismic waveforms generated by earthquakes, whose epicentral distances are from several tens to about a thousand kilometers. The method employed in the study was developed based on a prestack migration of shot gathers and is composed of the following procedure: (1) static correction, (2) the estimation of waveforms incident into a volume of interest, i.e., subsurface structure of the volcano, and (3) an inverse procedure using the developed migration scheme. The location of scatterers and the order of scattering became clear with the present analysis. The petrological implications and results from geoelectromagnetic studies by other researchers agree with the proposed model in which the existence of main and submagma reservoirs beneath the volcano were indicated. These results are interpreted in terms of a model on the magma migration path during the 1986 eruptive activity of the volcano. Seismic scattering analysis played a significant and indispensable role in this study to give a direct view of a possible underground plumbing system, and is considered a promising method for revealing the unknown structure of volcanoes in the future.

Remarkable changes in the total geomagnetic intensity were observed associated with the 1986 eruption of the Izu-Oshima Volcano. They are summarized as follows: (1) Long-term precursor: decrease in the total intensity at one station on the southern slope of the central cone, Miharayama, continued since 1981, with a constant rate of -5nT/yr. (2) Middle-term precursor: the decrease there accelerated beginning in April, 1986. (3) Short-term precursor: in October, 1986, an increase in the total intensity was observed at two stations on the north side of Miharayama, while readings at two southern stations decreased. (4) At the first stage of the Phase I eruption, step-like changes were observed at the two southern stations. (5) A decrease in the total intensity was observed at two other stations outside the caldera at the time of the fissure eruption on November 21, and a few survey points and one station showed significant changes. (6) For a few months after the eruption, no remarkable magnetic variations were found outside the caldera.(1), (2) and (3) are interpreted as thermal demagnetization of vent materials due to high-temperature volatiles dispatched from ascending magma. (4) is most likely due to rotation of vent materials. (5) is attributed to the piezomagnetic effect, together with the thermal demagnetization, due to intrusive dykes. In the 1950 eruption a demagnetized area with a 2km radius was formed at a depth of 5km (RIKITAKE, 1951a). In contrast, during the Phase II activity on November 21 and 22, 1986, an intrusive event is suggested to have occurred beneath the southeastern region of the volcano, as inferred from the observed total field changes.

Observations of groundwater temperature to an accuracy of 0.001 →C or better have been made at about 30 wells in various areas of impending earthquakes in Japan. The main aim of the observations was to monitor the crustal strain and/or the movement of groundwater which relate to earthquake occurrence. One thermometer was installed at a depth of 200 m in an active volcanic area, Usu, where an upward movement of the magma is occurring. We report here that there was a generally increasing temperature trend at this location: 0.3 →C in the half-year of observation. Decreases in the rate of increase preceded intense local earthquake activity. Temperature jumps were accompanied by large local earthquakes with magnitudes up to 4.2, and the polarity of the steps corresponded to the location of hypocentres. This is probably the first microtemperature measurement made in the proximity of seismic activity.

The activity of Usu volcano situated at southern Hokkaido is characterized by the persistent occurrence of earthquake swarms and remarkable ground deformations including the formation of lava domes, both of which are due to the high viscosity of its magma. After the pumice eruptions of August 1977, the central part of the summit crater bounded by a U-shaped fault upheaved day after day at the maximum rate of 1 m/day. Although the rate has decreased, the total upheaval reached to about 180 m as of September 1981 resulting in formation of a new cryptodome. The doming at the summit has caused the northeastern rim to thrust towards the northeast about 180 m, and consequently caused corrugation of the ground at the northeastern foot of the volcano. The two kinds of the deformations, upheavals and thrusts, are closely related with each other. To examine the relationship between the earthquake occurrences and the deformations, a quasi-continuous observation of the distance from the northeastern rim of the summit crater to the foot of the volcano, was carried out by an optical distancemeter for 44 hours. It was found that the thrusts were episodic and accompanied by relatively large earthquakes. This supports that the earthquake swarms are caused by stick-slip motions of frictional sliding at the planes of the doming faults.