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The water supply must be safe and sustainable. This requires a regulatory compliance, selection of an optimal water treatment process, timely response to water quality incidents as well as maintaining internal skills and knowledge among utility personnel to keep appropriate operational standards in the long run. Water supply services in Japan face various challenges, including a shrinking revenue base due to a declining population as well as a mass retirement of the baby-boomer generation. The Japan Water Research Center conducted questionnaire surveys and based on our findings developed the ‘knowledge transfer support system for water treatment technology’ for utilities to maintain internal skills and knowledge in the face of shrinking labour forces in the water sector. The system consists of three components: the database on water treatment technology, learning program on water treatment technology, and the assessment tool for knowledge transfer on water treatment technology.

BackgroundEmerging evidence suggests that fish consumption may have beneficial effects on mood disorders. However, no study has been reported on this issue in young adults to date. The aim of this study was to investigate the relationship between fish consumption and depressive symptoms in Japanese undergraduate students.MethodsThe 20-item Center for Epidemiologic Studies Depression Scale was used to measure depressive symptoms with a cut-off score of 16. A total of 4190 completed questionnaires (from 2124 men and 2066 women) were received for analysis.ResultsMultivariate logistic analysis showed that fish intake was inversely associated with risk of depressive symptoms in undergraduate students. After adjustment for possible confounders, the odds-ratios (95% confidence intervals) for fish intake 1–2 times/month, 1–2 times/week, 3–4 times/week, and almost every day (compared with “almost never”) were 0.78 (0.62–0.99), 0.70 (0.56–0.87), 0.67 (0.53–0.85) and 0.65 (0.46–0.92), respectively. This association tended to be stronger in women than in men.ConclusionsFrequent fish consumption in undergraduate students seems to moderate depressive symptoms. Further research is warranted to clarify the causality.

IgG4-related disease (IgG4-RD) is a newly recognized condition that is characterized by raised levels of serum IgG4, tissue infiltration of IgG4-positive plasma cells and presence of fibrosis. It affects multiple organs, including the pancreas, bile duct, and lacrimal and salivary glands. Skin lesions have rarely been reported, and those that have were described as distributed mainly in the head and neck region. We report a case of IgG4-RD with autoimmune pancreatitis and skin lesions on the trunk and limbs. The skin lesions responded well to oral prednisolone (PSL); however, tapering of PSL to 5 mg/day resulted in recurrence. At present, the skin disease is well controlled at a dose of 7 mg/day. Interestingly, IgG4 levels fluctuated with changes in the PSL dose but did not coincide with the severity of the skin disease, implying that the raised levels of IgG4 did not directly influence the skin symptoms.

During the great east Japan earthquake on March 11, 2011, a lot of ICT resources - telecom switching offices, optical fiber links, and so forth - were completely or partially damaged due to the tremor and the resultant tsunami. As a consequence, the demand for ICT services explosively increased, mainly because the people of the affected areas were trying desperately to communicate with the outside world that led to a phenomenal rise in the network traffic. In the Nippon Telegraph and Telephone (NTT) East Corporation alone, 385 telephone offices stopped operating immediately following the earthquake because of power outages and disruption of facilities. Approximately 1.5 million users were cut off from using fixed-line telephone service. The demand for fixed-line and mobile telephone services jumped up to 10-50 times the usual. This gave rise to serious traffic congestion, and the emergency ICT networks and services could not deal with this issue sufficiently. This article proposes a network architecture that is resilient even through devastating disasters by effectively exploiting specially designed movable and deployable resource units, which we refer to as MDRUs. An MDRU having the ability to accommodate communication and information processing functions can be rapidly transported or moved to the disaster zone, and can be deployed within a reasonably short time to establish the network at the disaster site and launch ICT services. The concept and configuration of the network architecture based on the MDRU and its features are described in this article. Some preliminary simulation results are also reported to evaluate the performance of our adopted MDRU-based disaster resilient network.

The aim of this study is to investigate the relationship between lowering of the insulation performance of ethylene propylene rubber (EPR) used as a covering material of a cross-linked polyethylene (XLPE) cable and partial discharges (PDs) and to establish a diagnostic technique using an acoustic emission (AE) sensor. An accelerated deterioration test was carried out and then the detected AE signals were evaluated. The results showed that not only the intensity of the AE signal but also the number of counted AE signals of more than a critical value was very useful for diagnosing the EPR. We also proposed a diagnostic sequence using an AE technique.

The aim of this study was to investigate, in a rat model, the effects of age on the amount of tooth movement and concomitant changes in alveolar bone turnover activity adjacent to orthodontically treated tooth roots. Rats (n = 48) of four different age groups (10, 30, 50, and 80 wk of age) were used in the experiment. Maxillary first molars were tipped mesially with a nickel titanium alloy coil-spring for 2 wk by a continuous force of 10 cN. Forty-eight age-matched untreated rats were used as controls. The changes in alveolar bone turnover were assessed histomorphometrically. Two weeks after the start of tooth movement, the amount of tooth movement was found to decrease with age and was significantly different among the four age groups. The histomorphometric study demonstrated that, in all experimental groups, turnover of alveolar bone increased significantly compared with that of each age-matched untreated group. However, the rate of increase decreased in an age-related manner. These results suggest that the age-dependent decrease in alveolar bone turnover activity, in response to mechanical forces, may negatively affect the amount of tooth movement.

In this paper, we examined the periodontal tissue reaction course of mice to mechanical stress according to the Waldo method, before examination of the transcription factor profile change. In the examination group, the arrangement of the periodontal ligament was irregular on specimen day 1. The extension and compression sites were observed at the opposite side of the roots. In day 1 and 3 specimens, the osteoclasts appeared in the compression sites. In day 7 specimens, the number of osteoclasts was reduced in number to less than that of day 3. Immunohistochemical examination revealed that the expression patterns of Runx2 and Msx2 were clearly dynamic changed compared to the control specimens. These results suggest that the appearance of transcription factors related to cell differentiation of periodontal ligament, which was due to the mechanical stress of insertion of elastic separator, happened within 24 hours.

The Japanese Lightning Detection Network (JLDN) has been operated to observed lightning occurring in Japan and its surrounding areas since 1998. The frequency of lightning flash is an important parameter for creating lightning protection designs. If the location accuracy of the Lightning Location System (LLS) is not good, it is very difficult to provide parameters for them. We have observed lightning current waveforms using Rogowski coils installed at wind turbines and evaluated the location accuracy of the stroke location estimated by the JLDN by the comparison with the position of the wind turbine. There are two continental scale lightning detection networks in the world. One is the North American Lightning Detection Network (NALDN) in the United States and Canada, and the other is the lightning detection network called European Cooperation for Lightning Detection (EUCLID) in Europe. We investigated the location accuracy of these networks with reference to various papers on their location accuracy. We compared the performances of the JLDN with that of the NALDN and the EUCLID. In the results, we showed that the JLDN has same performance as the NALDN and the EUCLID in location accuracy. However, some recent reports said the location accuracies of the NALDN and the EUCLID were improved by applying various techniques. In this paper, we show some solutions for improving the location accuracy of the JLDN at present.

Structural electrical and optical properties of AgInS2 (AIS) thin films grown by the single-source thermal evaporation method were studied. The X-ray diffraction spectra indicated that the AIS single phase was successful grown by annealing above 400 °C in air. The AIS grain sizes became large with increasing the annealing temperatures. All polycrystalline AIS thin films were sulfur-poor from the electron probe microanalysis and indicated n-type conduction by the Van der Pauw technique. It was deduced that the sulfur vacancies were dominant in the films and enhanced n-type conduction.

Structural and electrical properties of AgInS2 (AIS) thin films grown by single-source thermal evaporation method were studied. The X-ray diffraction spectra indicated that the AIS single phase was successfully grown by annealing above 400∘C in air. The grain size of the AIS crystals was above 2.5 μm from the surface photograph. Furthermore, the AIS grain sizes became large with increasing the annealing temperatures. All the samples indicated n-type conduction by the Van der Pauw technique. The carrier concentrations and the resistivities of the AIS films at room temperature were in the range of 1019–1022 cm−3 and 10−1–10−3 Ωcm, respectively. Therefore the mobilities increased from 0.6 to 6.0 cm2/Vs with increasing the grain sizes.

Purpose Upper extremity lymphedema (LE) is a harmful breast cancer complication. It has been reported that patient- or treatment-related risk factors of LE. Axillary reverse mapping (ARM) has been performed to prevent LE during axillary lymph node dissection (ALND) by visualizing the upper extremity lymphatics. We investigated whether ARM related factors included novel predictive risk factors of LE. Methods ARM revealed fluorescent axillary nodes (ARM nodes) in 76 patients by fluorescence imaging. Only ARM nodes within the ALND field were removed. Twenty-four (32%) patients developed LE (LE+) and 52 did not (LE−) during a median 24-month post-surgical follow-up period. We retrospectively evaluated the clinical features and ARM factors of LE+ and LE−. Results The positive ARM node rate among LE+ was 42%, significantly greater frequency than that among LE− (13%: p ≤ 0.05). Cranial collectors (lymphatic ducts along or above the axillary vein) were significantly more frequent in LE− (44%) than in LE+ (21%: p ≤ 0.05). Multivariate analysis revealed postoperative radiation and positive ARM nodes to be positive risk factors and cranial collectors to be a negative risk factor of LE. Conclusions ARM factors could predict the incidence of LE post-axillary surgeries in breast cancer patients.

This structure of turbulent flow in an annulus with strong inner cylinder wall heating has been studied in terms of velocity and temperature with wall temperatures up to 707 °C and a Reynolds number of 48,000. With increase in wall heating, the turbulence very close to the wall was suppressed due to an increase in the kinematic viscosity. In the inner region, the intermittent mixing became intensive and the turbulent intensity increased whereas, in the outer region, the turbulence was suppressed since intermittent mixing was no longer effective. The results show that the thermal structure can be considered in terms of a passive scalar for wall temperatures less then around 200 °C, except in the leading region of the heated area.

For the estimation of global climate change through analysis of the data from multiple satellite sensors, the intercalibration of the sensors is indispensable. In this paper, results of intercalibration of the newly developed VISSR for GMS-5 and NOAA-14 AVHRR are described. The method is based on collocated clear radiance observations with GMS-5 VISSR and NOAA-14 AVHRR. The results of the correlation analysis of the data of IR channels 1 and 2 of GMS-5 VISSR and those of channels 4 and 5 of NOAA-14 AVHRR indicate the following features. The observed brightness temperature with IR channel 1 of VISSR is about 0.8K–1.5K colder than that with channel 4 of AVHRR, while that with IR channel 2 is about 0.1K–1.0K warmer than that with channel 5 of AVHRR. The result of adjustment on working spectral response function and atmospheric correction indicates that the adjusted brightness temperatures with IR channels 1 and 2 of VISSR are about 1K colder than that with channels 4 and 5 of AVHRR. Thus this result shows IR channels 1 and 2 on GMS-5 indicate a certain disagreement with channels 4 and 5 of NOAA-14 AVHRR.

Active vitamin D3 is extensively used for the treatment of secondary hyperparathyroidism in hemodialysis patients. But it is often impossible to administer enough dose to suppress parathyroid hormone (PTH) level, because of hypercalcemia and hyperphosphatemia. New modalities with higher specificity for PTH suppression are desirable. We conducted a crossover comparative study of falecalcitriol, an active vitamin D3 analog, and alfacalcidol (1alpha[OH]D3). In this study, 25 hemodialysis patients with moderate to severe secondary hyperparathyroidism who had normal serum calcium levels were enrolled. They received daily oral doses of alfacalcidol during an 8-week observation period. Based on serum calcium levels and intact PTH, the subjects were allocated into two groups, and a comparative study was conducted using unmasked crossover design of two drugs x two periods. The dosage of both drugs was adjusted to maintain the initial serum calcium levels, and the relative change (%change) of serum biochemical parameters were compared. Comparison of two drugs in period 1 was taken as primary efficacy evaluation. Reproducibility of drug action was confirmed by comparing the effect of falecalcitriol between period 1 and 2. The percent change of PTH of falecalcitriol was lower than that of alfacalcidol: Those were, respectively, -7.89% and +30.42% for c-terminal PTH (P = 0.022), -4.39% and +38.88% for i-PTH (P = 0.077), and +3.68% and +30.52% for midregion PTH (P = 0.099). The similar changes were observed in the falecalcitriol group during period 2, confirming the reproducibility. Falecalcitriol was found to be superior to alfacalcidol in suppression of PTH levels in patients with moderate to severe secondary hyperparathyroidism when it is administered in equivalent doses that might maintain similar serum calcium levels.

Operational Calibration method of visible and IR channels of GMS-5 VISSR is as follows. In the visible channel, albedo is computed by the following equation. A={(C−b0)b1}2a−V0a, where C and V0 are digital counts from VISSR and V0 is bias voltage corresponding to 0 albedo respectively, other coefficients are determined from prelaunch test data. A principle of IR channel calibration depends upon a linear relation between incoming IR radiance and output voltage of IR channel. Taking the space as a cold source and a calibration shutter in VISSR as a high source, a calibration regression equation to convert output voltage of IR channel into temperature is determined. A little correction is necessary to compensate non-linear response characteristics of IR detector at low temperature. To cope with a malfunction of calibration shutter (not frequent occurrence) a method of calibration without a shutter information is developed. The monitoring of solar radiance for one year indicates a small degradation in visible channel detectors. The degradation among 4 detectors is not uniform.

The adhesion strength of thermal sprayed coatings is relatively low, and they sometimes tend to delaminate from the substrate during operation. In particular, sprayed ceramic coatings for thermal barriers, such as ZrO2, often delaminate because of thermal shock; therefore, ceramic coatings are often submitted to thermal shock tests. A nondestructive inspection method using ultrasound to detect the delamination of sprayed coating was proposed. In this study, a coating model was made with acrylic plates, and an ultrasonic test was applied to investigate the precision of detecting delamination by the ultrasonic testing method. Results indicate that delamination more than 1mm in diameter can be detected by the ultrasonic testing method. Moreover, the delaminating process of sprayed coatings under thermal shock tests can be detected by this method.

For shaping a beam of millimeter-wave reflectarrays arbitrarily, this paper proposes a directivity synthesis based on the algorithm of the phase-retrieval method. The unknown phase distribution is numerically determined from an illumination distribution on the aperture and a desired beam pattern by iterative approach. As a design example, we present an elliptical-beam microstrip reflectarray with an offset feed. The effectiveness of the proposed reflectarray is verified by the near-field antenna measurements at 45 GHz.

Discharging rarefied gas jets in low‐pressure conditions are interesting and important phenomena from an engineering point of view. For example they relate to the attitude control of the space satellite, or the semiconductor technology. The jets, however, deform to the complicated shapes by interacting with solid walls. In this paper we have performed the experiments the flow visualization as a first step by applying the LIF (Laser Induced Fluorescence) method on the jet‐wall interaction. Jet is spouting out from a φ1.0 mm circular hole into the low pressure air chamber, impinging on a flat plate. The LIF visualization of interacting rarefied gas jet is carried out by using the iodine (I2) tracer and argon ion laser.

1. Fast (posterior latissimus dorsi, PLD) and slow (anterior latissimus dorsi, ALD) muscles of the chick were studied by time-resolved X-ray diffraction using a synchrotron radiation source. 2. In both muscles and at both 20 and 30 degrees C, intensities of the X-ray equatorial reflections changed faster than tension at the beginning of tetanus. When the intensity change was converted into the mass transfer from the thick to the thin filament, the difference between the half-rise times of the transfer and tension development at 20 degrees C was 140 ms in ALD and 37 ms in PLD. At 30 degrees C it was 110 ms and 10-20 ms for ALD and PLD respectively. 3. These results indicate that in the early stage of contraction, some of the myosin heads in the vicinity of the thin filament are developing little or no tension, and suggest that the fast and slow muscles differ in the transition rate of myosin heads from the state of attachment with low tension to that with high tension.

Early changes of Runx2 and Msx2 expressions were examined by immunohistochemistry in mouse periodontal ligament exposed to mechanical stress. 8-week-old ddY mouse was used as experimental animal. To provide a continuous mechanical stress on periodontal ligament, rubber dam sheet was placed between upper molars of the mouse. At 20 minutes, 1 hour, 3 hours, 9 hours and 24 hours after insertion of the sheet, relevant parts of the mouse tissues were excised and fixed in 4% paraformaldehyde/0.05M phosphate buffered fixative solution. Then serial paraffin sections were prepared and histopathological evaluation as well as examination of Runx2, Msx2 and alkaline phosphatase (ALP) expressions by immunohistochemistry were performed. Control animals were not subjected to mechanical stress. In the experimental group, strong expressions of Runx2 and Msx2 were seen in periodontal fibroblasts of the tension side at 20 minutes after mechanical stress. Expressions of Runx2 and Msx2 became stronger in parallel with time, and at 24 hours after mechanical stress, the periodontal fibroblasts, cementoblasts as well as osteoblasts showed strong expression. Moreover, ALP has also demonstrated similar strong expression. On the other hand, in the control group, although expressions of Runx2, Msx2 and ALP were detected at all the experiment times, the expressions were weak. All these results strongly suggested that Runx2 promoted differentiation of osteoblasts at early stage and Msx2 worked as an activator of Runx2 function.

We investigated the expression pattern of Jagged1 peptide in mandibular condylar cartilage, as a type of secondary cartilage. Mandibular condyle of ddY mice were fixed from embryonic day 15 (E15) through just after birth (equivalent to E19). Serial sections were examined using histological immunohistochemical (IHC) techniques. At E15, the proliferating cells had positive products of Jagged1 in their cytoplasms and cell membrane of almost all coagulating cells. At E17, cytoplasmic and membranuous reactions of Jagged1 factors appeared strongly in the cells just inside the condylar cartilage sheath. At E18, Jagged1 positive products were observed in almost all cells of the layers, and they were mostly distinct in the sheath of the condyle. At just after birth, Jagged1 was observed in a portion of almost all layer cells in their cytoplasm and membrane. These results suggest that Jagged1 plays an essential role for mandibular condylar cartilage morphogenesis and development.

Expression pattern of Jagged2 gene in mandibular condylar cartilage was examined by means of in situ hybridization (ISH) technique. At E14, Jagged2 mRNA signals appeared in cytoplasm of proliferating chondrocytes. From E15 to E19, Jagged2 mRNA was detected throughout almost all cytoplasm in all layers. However, the distribution pattern was not uniform. These results suggest that Jagged2 plays an essential role for mandibular condylar cartilage morphogenesis and development.

Inorganic polyphosphates [Poly(P)] are often distributed in osteoblasts. We undertook the present study to verify the hypothesis that Poly(P) stimulates osteoblasts and facilitates bone formation. The osteoblast-like cell line MC 3T3-E1 was cultured with Poly(P), and gene expression and potential mineralization were evaluated by reverse-transcription polymerase chain-reaction. Alkaline phosphatase activity, von Kossa staining, and resorption pit formation analyses were also determined. The potential role of Poly(P) in bone formation was assessed in a rat alveolar bone regeneration model. Poly(P) induced osteopontin, osteocalcin, collagen 1α, and osteoprotegerin expression and increased alkaline phosphatase activity in MC 3T3-E1 cells. Dentin slice pit formation decreased with mouse osteoblast and bone marrow macrophage co-cultivation in the presence of Poly(P). Promotion of alveolar bone regeneration was observed locally in Poly(P)-treated rats. These findings suggest that Poly(P) plays a role in osteoblastic differentiation, activation, and bone mineralization. Thus, local poly(P) delivery may have a therapeutic benefit in periodontal disease.

A 10-year-old Japanese male with multiple blister formation and palpable purpura in the course of anaphylactoid purpura is described. Histologically, the lesions showed leukocytoclastic vasculitis in the upper dermis with subepidermal clefts. Blister fluid showed matrix metalloproteinase (MMP) 2 and MMP-9 gelatinolytic activities using zymography. These enzymatic reactions, especially that involving MMP-9 derived from polymorphonuclear leukocytes, might play an important role in the pathophysiology of this condition.

A rabbit experimental mandibular defect was reconstructed with 1% atelocollagen gel including rhBMP-2 10microg and a covering a poly (lactic-co-glycolic acid) copolymer (PLGA) membrane. For this experiment, eight male rabbits were used and a histological study was conducted. Our study purpose was to examine the effects and fate of PLGA membrane during bone reconstruction. PLGA membrane was phagocytized by foreign body giant cells and macrophages in the healing course of reconstruction osteogenesis. These histological data suggest that the PLGA membrane was gradually absorbed and replaced by fibrous connective tissue or bone tissue. In the osteogenesis course, the outer periphery of the new bone was maintained by PLGA membrane without expansion.

For the experimental animals, eight rabbits were chosen. A bone defect was made and was filled with 1% atelocollagen gel including rhBMP-2 10 microg. The reconstruction course was observed using micro-computed tomography (muCT) in vivo. In muCT observation, the density was slightly elevated at the bone marrow side at day 7, and the phenomenon gradually expanded during the course of this experiment which lasted for 28 days. By utilized muCT, we could construct 3D images, and that process enabled us to visualize bone formation more closely. These data suggest that the experimental animal model muCT and 3D image are extremely useful for follow-up of reconstruction of animal bone defects and that the atelocollagen gel is effective as a carrier of rhBMP-2.

In Japan, some leading industries and companies have started to apply the eco-efficiency concept in their management, decision-making and/or communication tools with stakeholders. Although still experimental, the eco-efficiency increasingly gains recognition as effective concept at the sectoral /corporate level and at a product level. In this paper, we first describe how the eco-efficiency concept is practiced; especially at a product level for that there are multi-attribute evaluation items. Second, we present an overview of eco-efficiency related activities in Japan, such as eco-efficiency project (funded by the Ministry of Economy, Trade and Industry of Japan. Finally, we introduce one of the project activities, an eco-efficiency handbook that was issued in 2004 and describe coordinating methodologies and steps in the development of eco-efficiency indicators.

Contraction of cardiac muscle is regulated by changes in the concentration of intracellular Ca(2+) . An increase in the Ca(2+) concentration results in enhanced contractility of cardiac muscle. It is also known that cardiac contractility is influenced by changes in Ca(2+) sensitivity of contractile elements. Recent studies at the molecular level have revealed the complexity of the regulation of Ca(2+) sensitivity of contractile elements.

In this immunohistochemical examination, the expression of Notch1 peptide was detected in neoplastic cells in a case of osteosarcoma of the maxilla of a 31-year-old Indonesian male patient. Notch1 peptide appeared in the cytoplasm of neoplastic cells of comparatively well-differentiated areas of the osteosarcoma, an osteoblastic area containing osteoid and/or immature bone tissues. The results suggest that Notch1 is closely related to cytological differentiation or acquisition of cytological characteristics in neoplastic cells of osteosarcoma.

We have investigated the long term reliability of a polymer insulators. Especially, we need to grasp the discharge form of the leakage current in various outdoor exposure sites, and thus construct a database for different contaminated environments. In this paper, we have constructed a measurement system which can make automatic remote monitoring of leakage current data using the Internet. We have applied the system to a field test.

We have developed a measuring system to separate leakage current of polymer material for outdoor insulator into three frequency components. We discuss the relation between discharge types and degradation on the surface of polymer materials for outdoor insulators. The special attention is paid to the discharge form in a salt fog test by considering each frequency component. Discharge image is analyzed by gaining the light emission intensity distribution using image-processing technology, allowing us to investigate the relationship between the three frequency components of the leakage current and discharge light emission.

A broadcast technique for encrypted communication is proposed that offers high levels of security with high transmission efficiency. Any encryption algorithm can be used without significantly degrading ciphertext length. The proposed scheme can use parallel processing techniques to realize rapid encryption speeds. Plaintext is processed to yield one common component and as many individual components as there are receivers. Because the common component is used for all receivers, the ciphertext is relatively short. If a public key cryptosystem is used, any receiver's decrypted plaintext can be compared with that of another receiver, thus preventing malicious sender attack. >

This paper proposes a 6.4-kbit/s extension to the G.729 speech coder. Each G.729 module was investigated to determine which bits could be removed without hurting the speech quality, then a 6.4-kbit/s coder was designed. This coder has an 11-bit algebraic codebook that uses two or three pulses. We also propose a conditional orthogonalized search for the fixed codebook to improve the speech quality. The conditional orthogonalized search chooses one of two search methods (orthogonalized or non-orthogonalized) based on the optimum pitch gain. Subjective tests have indicated that the quality of the proposed coder is equivalent to that of the 6.3-kbit/s G.723.1 coder.

This paper discusses a method for solving the optimization problem of district heating and cooling energy supply system, to obtain the optimal selection of the required equipment. The proposed method uses the extended DP algorithm newly developed by the authors, aiming to relax the combinatorial explosion. By using this method, the problem was effectively solved almost in real time.

It is well known that, in a state of weightlessness, body fluids shift toward the head site, but the actual rates of the migration of fluids has never been measured. In order to identify the causes of reduced orthostatic tolerance and the reduction in circulating blood volume after returning from a space mission, it is necessary to measure the changes in body fluid distribution. Although the methods for measuring changes in body fluids include the use of isotopes or pigments, such methods cannot be employed in space due to their invasive properties. Therefore, we directed our attention toward the impedance method, for which we developed a non-invasive apparatus for measuring the distribution of body fluids. We therefore measured the actual distribution of body fluids using the bed-rest method, a model of the zero gravity state.

A multi-compartment model was used to estimate Ca2+ gradients in a sarcomere of a cardiac myocyte. The mathematical model assumed Ca2+ release from the sarcoplasmic reticulum as a driving function, and calculated Ca2+ binding to myoplasmic buffers, Ca2+ uptake by the sarcoplasmic reticulum, and diffusion of Ca2+ (and the buffers). During the fast Ca2+ transient similar to those observed during a twitch, the model predicted a large Ca2+ gradient in the sarcomere. A trajectory of the instantaneous relation between spatially averaged concentrations of Ca2+ and the Ca2+-troponin complex showed a counterclockwise loop, indicating non-equilibrium Ca2+ binding to troponin. During slow changes in [Ca2+] with time to peaks of approximately 500 ms or longer, the gradient of [Ca2+] was largely dissipated and the apparent equilibrium of the Ca2+-troponin binding reaction was suggested with little hysteresis of the trajectory. We conclude that a steady-state relation between [Ca2+] and mechanical activity can be achieved uniformly in the sarcomere by slowing the rate of Ca2+ release from the sarcoplasmic reticulum.