The Fukushima Nuclear Power Plant accident and exposures in the environment

The Great East Japan Earthquake has occurred on March 11, 2011, in the Tohoku District of Japan. Due to the earthquake, big tsunamis were induced, and they rushed to the Fukushima Nuclear Power Stations, causing severe accidents. Radioactive materials including I-131, Cs-137 and so on were emitted from the plant to the environment. The Japanese government, Fukushima prefectural government and other local governments have struggled against the accidents. The restricted area and deliberate evacuation area are set by the government, and the residents are evacuated. The dose rates in and around Fukushima Prefecture have been monitored by the governments and other involved organizations. Fukushima government has started the health management survey for all residents in Fukushima Prefecture including the questions on their activities for the estimations of their external doses.     

Chemical sensitivity of the male daphnid, Daphnia magna, induced by exposure to juvenile hormone and its analogs

It was reported that males daphnid Daphnia magna that have been induced by methyl farnesoate exposure exhibit higher tolerance to chemical compounds such as potassium dichromate and pentachlorophenol than females. Male neonates are also known to be induced by exposure to juvenile hormone analogs, such as fenoxycarb and pyriproxyfen. If these analogs can be used to produce male progeny, the biological and physiological studies of daphnid male would be progressed since the effects of these analogs were several hundred times higher than that of methyl farnesoate. Therefore, in the present study, it was investigated that the chemical sensitivity of male neonates induced by exposure to juvenile hormone (methyl farnesoate) and its analogs. The minimum concentrations of methyl farnesoate, fenoxycarb and pyriproxyfen to induce 100% male-reproduction were 200nM (50microg/l), 0.23nM (70ng/l) and 0.31nM (100ng/l), respectively. In addition, no reduction of relative reproduction was observed at the juvenoid concentrations in 24h exposure producing 100% male progeny. The median effective concentrations (EC50) of potassium dichromate for immobility of male neonates, established by a standardized method for investigating sensitivity to chemicals, were significantly higher (12-29%) than that of females at least after 24h exposure in all the male neonates induced by juvenoids used in this study (P<0.05). This study demonstrated that the male daphnids induced by exposure to juvenile hormone and its analogs exhibit similar chemical tolerance.     

Isotope ratios of lead in Japanese women’s hair of the twentieth century

Introduction  

Isotope ratios of lead (²⁰⁷Pb/²⁰⁶Pb and ²⁰⁸Pb/²⁰⁶Pb) in Japanese women’s hair of the twentieth century were measured to evaluate lead contamination of human proximate environment of those days.     

Formation of Friedel’s salt in simulated municipal solid waste incineration bottom ash

Journal of Material Cycles and Waste Management - To recycle incineration bottom ash as a raw material in cement production, it is important to reduce the chlorides in the ash. Due to...     

Large- and small-size advantages in sneaking behaviour in the dusky frillgoby <Emphasis Type="Italic">Bathygobius fuscus</Emphasis>

Sneaking tactic, a male alternative reproductive tactic involving sperm competition, is generally adopted by small individuals because of its inconspicuousness. However, large size has an advantage when competition occurs between sneakers for fertilization of eggs. Here, we suggest that both large- and small-size advantages of sneaker males are present within the same species. Large sneaker males of the dusky frillgoby Bathygobius fuscus showed a high success rate in intruding into spawning nests because of their advantage in competition among sneaker males in keeping a suitable position to sneak, whereas small sneakers had few chances to sneak. However, small sneaker males were able to stay in the nests longer than large sneaker males when they succeeded in sneak intrusion. This suggests the possibility of an increase in their paternity. The findings of these size-specific behavioural advantages may be important in considering the evolution of size-related reproductive traits.     

Development of a simulation model for reuse businesses and case studies in Japan

To discuss measures to promote reuse in society, a holistic understanding of reuse businesses and markets is indispensable. This paper presents a simulation model for reuse businesses. To formulate the model, first, prerequisites for reuse businesses are outlined. The simulation model includes these prerequisites as its parameters, and its outcomes yield patterns of reuse markets. The paper presents the formulation of the model and simulation outcomes under four parameter settings. The correspondences between the simulation outcomes and case studies of reuse businesses in Japan are discussed to verify the propriety of the model.     

Mandibular morphogenesis during soldier differentiation in the damp-wood termite<Emphasis Type="Italic"> Hodotermopsis sjoestedti</Emphasis> (Isoptera: Termopsidae)

The conspicuous morphogenesis during termite soldier differentiation is one of the most remarkable examples of specialized caste development in social insects. To clarify the mechanism of morphological changes during soldier differentiation, mandibular morphogenesis prior to the presoldier moult was examined in the damp-wood termite Hodotermopsis sjoestedti. Using experimental induction of presoldier differentiation from pseudergates (7th or later instar larvae) by the application of juvenile hormone analogue (JHA), we compared mandibular morphogenesis in a presoldier moult (from pseudergate to presoldier) with that of a stationary moult (from pseudergate to pseudergate). Future presoldier mandibles were formed under the old mandibular cuticle of the pseudergates just prior to the presoldier moult. Multiple folds of both epidermis and new cuticle were observed in the developing mandible, and large concavities between teeth were formed on the mandibular surface. While in the stationary moult, the future mandibles were formed with a smooth surface. The process of the mandibular morphogenesis in soldier differentiation explains the allometry of soldier mandibles. The morphological differences in mouth parts between castes arise from a switching mechanism that triggers caste-specific mandibular epithelial growth during development.     

Measurement of fetal urine production in mild infantile polycystic kidney disease—A case report

It is generally recognized that the sonographic findings of infantile polycystic kidney disease (IPKD) are bilaterally enlarged kidneys, oligohydramnios, an absent fetal bladder, and the typical kidney texture. Since there is a broad spectrum of renal compromise with IPKD, in utero diagnosis is thought to be limited to the severe forms. This paper reports a mild case of IPKD, where the in utero diagnosis was established by measuring fetal urine production and amniotic fluid volume serially during pregnancy, and by ultrasonographic examination of fetal kidneys.