WILLINGNESS TO PAY FOR FLOOD RISK REDUCTION AND ITS DETERMINANTS IN JAPAN1

ABSTRACT: This study aimed to clarify public preferences for flood control measures in Japan, willingness to pay (WTP), and the main factors involved in WTP by applying the contingent valuation method. Findings showed that most residents surveyed expected some flood control measures, and revealed a diversity of interest in river management. WTP levels for different measures ranged from a mean of ¥2,887 to ¥4,861 and from a median of ¥1,000 to ¥2,000. However, WTP for additional flood risk reduction beyond initial levels was found to be zero. This was considered to be because WTP for flood risk reduction must be determined within a multi‐risk context. WTP for flood control measures may increase with per capita income, individual preparedness, and/or experience with flooding, but may decrease with distance from a river, acceptability of flood risk, and provision of environmental information. Furthermore, perception of flood risk may increase WTP, while perception of other risks may decrease it. Methods of dealing with environmental risk that were proposed in the survey may have affected WTP levels.     

Relationship between the growth and survival of larval Pacific bluefin tuna, Thunnus orientalis

We tested the hypothesis that a large body size and rapid growth rate affect the survival of larval Pacific bluefin tuna, Thunnus orientalis (PBT), and analyzed larval growth in relation to environmental conditions. Seven high density larval patches of PBT were tracked with reference buoys in the northwestern Pacific Ocean for 28–171 h in May–June from 2004 to 2008. The otolith radii and daily growth rates of the survivor larvae (collected on later tracking days of each tracking session) tended to be larger and more rapid, respectively, than those of original larvae (collected on earlier tracking days). A large body size was found to positively affect the survival of larval PBT, as did a rapid growth rate, even at an early larval stage (7 days after hatching). Generalized linear modeling showed that the otolith radius was influenced positively by the sea temperature, stratification parameter and food density, while the growth rate was influenced positively by the sea temperature and food density.     

Individual differences in nest defense in the colonial breeding Black-tailed Gulls

Often in colonial seabirds, all colony members are believed to defend against nest predators and experience equal nest predation risk. However, the variation of defense behavior among members and its reproductive consequences are largely unknown. We investigated (1) individual variation in the nest defense of breeding Black-tailed Gulls Larus crassirostris against a natural egg predator, the Jungle Crow Corvus macrorhynchos and (2) how this behavioral variation affects an individual’s own nest predation risk and that of their neighbors. Results were compared between 2 years where crow attack levels were manipulated to average 5 and 22 times normal rates (“low” and “high” predation risk years, respectively) by the placement of varying numbers of artificial nests containing unguarded eggs at the perimeter of the gull colony. In both years, 23–38% of parents, mostly males, showed “aggressive” defense behavior (strikes or chases) against crows and decoys. Other “non-aggressive” gulls showed no defense. In the year of low predation risk, intrusion rates by crows (landing within 0.5 m of an individual gull’s nest) were similar for aggressive and non-aggressive gulls. In the year of high predation risk, however, the rates of intrusion for aggressive gulls (4%) and for non-aggressive gulls with an aggressive neighbor (37%) were significantly lower than for non-aggressive gulls without an aggressive neighbor (76%). These results indicate that aggressive individuals reduce nest predation risk for themselves and conspecific neighbors in a colonially breeding species.     

Three-dimensional diffusion of non-sorbing species in porous sandstone: computer simulation based on X-ray microtomography using synchrotron radiation

The diffusion pathways of porous sandstone were examined by a three-dimensional (3-D) imaging technique based on X-ray computed tomography (CT) using the SPring-8 (Super Photon ring-8 GeV, Hyogo, Japan) synchrotron radiation facility. The analysis was undertaken to develop better understanding of the diffusion pathways in natural rock as a key factor in clarifying the detailed mechanism of the diffusion of radionuclides and water molecules through the pore spaces of natural barriers in underground nuclear waste disposal facilities. A cylindrical sample (diameter 4 mm, length 6 mm) of sandstone (porosity 0.14) was imaged to obtain a 3-D image set of 450(3) voxels=2.62(3) mm(3). Through cluster-labeling analysis of the 3-D image set, it was revealed that 89% of the pore space forms a single large pore-cluster responsible for macroscopic diffusive transport, while only 11% of the pore space is made up of isolated pores that are not involved in long-range diffusive transport. Computer simulations of the 3-D diffusion of non-sorbing random walkers in the largest pore cluster were performed to calculate the surface-to-volume ratio of the pore, tortuosity (diffusion coefficient in free space divided by that in porous rock). The results showed that (i) the simulated surface-to-volume ratio is about 60% of the results obtained by conventional pulsed-field-gradient proton nuclear magnetic resonance (NMR) laboratory experiments and (ii) the simulated tortuosity is five to seven times larger than the results of laboratory diffusion experiments using non-sorbing I(-) and Br(-). These discrepancies are probably attributed to the intrinsic sample heterogeneity and limited spatial resolution of the CT system. The permeability was also estimated based on the NMR diffusometry theory using the results of the random walk simulations via the Kozeny-Carman equation. The estimated permeability involved an error of about 20% compared with the permeability measured by the conventional method, suggesting that the diffusometry-based NMR well logging with gradient coils is applicable to the in-situ permeability measurement of strata. The present study demonstrated that X-ray CT using synchrotron radiation is a powerful tool for obtaining 3-D pore structure images without the beam-hardening artifacts inevitable in conventional CT using X-ray tubes.     

Deposition velocity of PM2.5 sulfate in the summer above a deciduous forest in central Japan

In order to increase knowledge of aerosol dry deposition for the regional assessment of acid deposition and transboundary air pollution in East Asia, an experimental study on PM2.5 sulfate deposition was implemented in the early summer of 2009. The experimental field was located in a deciduous forest at the foot of Mt. Asama, central Japan. Aerosol fluxes were obtained using the aerodynamic gradient method. Three aerosol samplers were placed on an experimental tower at 21, 24 and 27 m above the ground surface, and collected PM2.5 on filters for chemical analysis. Vertical concentration differences between 21 m and 27 m of PM2.5 sulfate were detected significantly when the concentration exceeded 1 μg m^?3. Mean deposition velocity was estimated to be 0.9 ± 1.0 cm s^?1 in the daytime and 0.3 ± 0.3 cm s^?1 in the nighttime. In the case that a height-dependent correction in the roughness sub-layer was taken into account, the deposition velocities increased more, especially in daytime. Higher deposition velocities in the daytime were associated with larger friction velocities and unstable conditions. The deposition velocities observed in this study were in agreement with other experimental results found in the literature. On the other hand, they were higher than those calculated by theoretical models. Two empirical parameterizations (Wesely, M.L., Cook, D.R., Hart, R.L., 1985. Measurement and parameterization of particulate sulfur dry deposition over grass. Journal of Geophysical Research 90, 2131–2143; Ruijgrok, W., Tieben, H., Eisinga, P., 1997. The dry deposition of particles to a forest canopy: a comparison of model and experimental results. Atmospheric Environment 31, 399–415) were validated by the observations. The general trend of higher daytime and lower nighttime deposition velocities was similar among the observation and the two parameterizations. The large variability found in the measurement was not reproduced by the parameterizations, because it is attributable to random error from the differences between the samplers. The observations were in accordance with the parameterization of Ruijgrok et al. (1997) for a forest, although much larger than that of Wesely et al. (1985) for grasslands. This indicates the large difference in aerosol deposition velocities between forests and grasslands.     

Influence of transportation and pumping on the properties of concrete with large amount of copper slag fine aggregate in actual construction of port and harbor structures

Journal of Material Cycles and Waste Management - Copper slag fine aggregate (CUS) is 30% denser than normal aggregate is an effective material for port and harbor structures demanding high-density...     

Effects of parabens on apoptosis induced by serum-free medium

Alkyl esters of p-hydroxybenzoic acids (parabens), an endocrine disrupter, are used as preservatives in cosmetics and foods. In this study, to understand the relationship between parabens and differentiation in infants, the effects of parabens on apoptosis induced by serum deprivation in PC12 cells were investigated. In addition, apoptosis-related factors were assayed. As results, a tendency toward enhancement of apoptosis was observed in the cells cultured in the serum-free medium with methylparaben, and this tendency was suggested to be related to the contents of BAD, a pro-apoptotic protein. Butylparaben did not show any tendency to enhance apoptosis.     

New technique using galactose-specific lectin for isolation of fetal cells from maternal blood

To isolate fetal cells from maternal blood, we developed a new method based on galactose-bearing conjugation. Nucleated red blood cells (NRBCs), which highly express galactose on their surface, were selectively attached to a substrate coated with a galactose-containing polymer via soybean agglutinin (SBA), a galactose-specific lectin. Cord blood samples were used to evaluate enrichment efficacy of NRBCs by this method. Blood samples were obtained from 131 pregnant women between 6 and 27 gestational weeks. After preliminary condensation of fetal cells by Ficoll gradient centrifugation, NRBCs were enriched using galactose-positive selection by adjusting SBA concentration. We isolated one to severalhundred NRBCs (mean±SD, 7.8±8.5) in 2.3 ml of peripheral blood samples from 96% of pregnantwomen. The isolated NRBCs were analyzed by a Y-chromosome FISH probe in eight cases carrying male fetuses. Y-signals were detected in all eight cases and more than half of the NRBCs wereoffetal origin. The study demonstrates that our new method using galactose-specific lectin provides effective enrichment of fetal NRBCs allowing non-invasive prenatal diagnosis. Copyright © 2002 John Wiley & Sons, Ltd.