The frequency of exposure to strong magnetic fields has increased as the magnetic-resonance image-diagnostic technique (MRI) and passenger transport systems based on the principle of magnetic levitation have come into wider use. Accordingly, it has become necessary to more systematically assess their influence on the body and set strict guidelines on acceptable limits of magnetism exposure. Therefore, we have assessed the influence of an uniform static magnetic field (8 T in maximum) on normal erythrocytes. The erythrocytes were oriented with their disk plane parallel to the magnetic field direction. These erythrocytes were influenced even by 1 T and almost 100% of them were oriented when exposed to 4 T. Furthermore, the degree of orientation was not influenced by the state of hemoglobin (oxy: diamagnetic, deoxy and met: paramagnetic). The dependence of the measured degree of orientation on the intensity of the magnetic field was in good agreement with the theoretical equation for the magnetic orientation of diamagnetic substances. As a result of a numerical analysis based on the equation, the anisotropic diamagnetic susceptibility of erythrocytes was found to be delta chi = 8 x 10(-22) electromagnetic units/erythrocyte. It was almost in agreement with the calculated value delta chi = 6 x 10(-22) emu/erythrocyte estimated from the diamagnetism of the membrane constituents of erythrocyte.

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Summary 1. Understanding mechanisms behind the distribution of organisms along a gradient of hydrological connectivity is crucial for sustainable management of river–floodplain systems. We tested the hypothesis that frequency of flood pulses exerts a direct influence on the distribution of freshwater mussels (Unionoida) by creating a local environment that limits their fitness. 2. Multiscale habitat analyses combined with transplant‐rearing experiments were carried out with a focus on abundance, presence/absence, survival rates and growth rates of mussels. Sixty‐nine floodplain waterbodies (FWBs) were surveyed within a 15‐km lowland segment of the Kiso River in Japan. 3. The abundance of mussels significantly increased with increased frequency of inundation associated with flood pulses at the among‐FWB scale, while the probability of occurrence of mussels was negatively predicted by the amount of benthic organic matter at the within‐FWB scale. 4. Field‐rearing experiments showed that survival rates were low and growth rates nearly zero in infrequently inundated FWBs (these FWBs had no naturally occurring resident mussels). In such FWBs, hypoxia (DO < 2 mg L−1) was frequently observed near the bottom when temperature was optimal for mussel growth (>15 °C). 5. These findings demonstrated that flood pulse frequency was the most important factor in determining mussel distribution in FWBs because it directly limits mussels’ fitness by mediating local environmental factors, possibly dissolved oxygen (DO) levels. Successful restoration efforts for mussel habitat conservation should focus on processes that lead to improved local conditions.

The frequency of exposure to strong magnetic fields has increased as the magnetic-resonance image-diagnostic technique (MRI) and passenger transport systems based on the principle of magnetic levitation have come into wider use. Accordingly, it has become necessary to more systematically assess their influence on the body and set strict guidelines on acceptable limits of magnetism exposure. Therefore, we have assessed the influence of an uniform static magnetic field (8 T in maximum) on normal erythrocytes. The erythrocytes were oriented with their disk plane parallel to the magnetic field direction. These erythrocytes were influenced even by 1 T and almost 100% of them were oriented when exposed to 4 T. Furthermore, the degree of orientation was not influenced by the state of hemoglobin (oxy: diamagnetic, deoxy and met: paramagnetic). The dependence of the measured degree of orientation on the intensity of the magnetic field was in good agreement with the theoretical equation for the magnetic orientation of diamagnetic substances. As a result of a numerical analysis based on the equation, the anisotropic diamagnetic susceptibility of erythrocytes was found to be delta chi = 8 x 10(-22) electromagnetic units/erythrocyte. It was almost in agreement with the calculated value delta chi = 6 x 10(-22) emu/erythrocyte estimated from the diamagnetism of the membrane constituents of erythrocyte.

This study tested the applicability of airborne scanning laser altimetry (LiDAR) for characterizing surface connectivity of floodplain water bodies by comparing it with in situ measurements of water levels, and examined whether LiDAR derived data accurately predicted the occurrence of globally imperilled unionid mussels. We intensively examined 10 isolated and 3 connected floodplain water bodies (IWBs and CWBs, respectively) located within a 15‐km lowland segment of the Kiso River in Japan. Using a digital elevation model (DEM) of floodplain ground surface, which is derived from LiDAR, and water surface DEM, which is obtained from records of water level fluctuations, the frequency of surface connectivity between IWBs and the main channel (inundation frequency) was calculated. Inundation frequency of IWBs was also measured in situ using water level and temperature probes. Also, the occurrence of mussels in CWBs and IWBs were examined. LiDAR derived data well predicted in situ derived one with a high level of accuracy (r2 > 0.77), validating the LiDAR‐based approach. Some errors existed in the predictive model, indicating that the applicability of LiDAR data is limited by its spatial resolution and snapshot nature. The occurrence of mussels was positively explained by an increasing level of inundation frequency, and the high accuracies of empirical models were validated using data for other 67 water bodies within the study segment. This study overall demonstrated a high potential of LiDAR data for efficiently monitoring hydrological and biological conditions of floodplain water bodies in the Kiso River and beyond. Copyright © 2010 John Wiley & Sons, Ltd.