Risk Assessment of the Carbon Nanotube Group

This study assessed the health risks via inhalation and derived the occupational exposure limit (OEL) for the carbon nanotube (CNT) group rather than individual CNT material. We devised two methods: the integration of the intratracheal instillation (IT) data with the inhalation (IH) data, and the “biaxial approach.” A four‐week IH test and IT test were performed in rats exposed to representative materials to obtain the no observed adverse effect level, based on which the OEL was derived. We used the biaxial approach to conduct a relative toxicity assessment of six types of CNTs. An OEL of 0.03 mg/m³ was selected as the criterion for the CNT group. We proposed that the OEL be limited to 15 years. We adopted adaptive management, in which the values are reviewed whenever new data are obtained. The toxicity level was found to be correlated with the Brunauer‐Emmett‐Teller (BET)‐specific surface area (BET‐SSA) of CNT, suggesting the BET‐SSA to have potential for use in toxicity estimation. We used the published exposure data and measurement results of dustiness tests to compute the risk in relation to particle size at the workplace and showed that controlling micron‐sized respirable particles was of utmost importance. Our genotoxicity studies indicated that CNT did not directly interact with genetic materials. They supported the concept that, even if CNT is genotoxic, it is secondary genotoxicity mediated via a pathway of genotoxic damage resulting from oxidative DNA attack by free radicals generated during CNT‐elicited inflammation. Secondary genotoxicity appears to involve a threshold.     

Associating Gene Therapy with the Human Genome Project

As is often the case with cutting-edge biomedical technology, the introduction of gene therapy in Japan provoked discussions of ethics and safety while offering little hope for dramatic recovery. Nevertheless, only 5 years after the first authorized clinical trial in the USA, the first Japanese trial was conducted in 1995. This trial event garnered extensive media coverage but yielded little opposition. To understand the public reaction, a range of sources were examined, including news media and popular scientific magazines. In the case of Japan, public acceptance did not mean enlightened consent; rather, it meant that interactions among researchers, the media, and the populace brought about a new interpretation of the technology.     

Preoperative sexual status of Japanese localized prostate cancer patients: comparison of sexual activity and EPIC scores

Objective: This study aimed to evaluate the relationship between sexual activity and sexual function using questionnaires distributed to middle-aged Japanese patients with localized prostate cancer.

Methods: A total of 145 patients who underwent radical prostatectomy were enrolled in the survey reported on herein. Sexual activity and sexual function were investigated via the Expanded Prostate Cancer Index Composite (EPIC) and an original self-reported questionnaire.

Results: Of participants, 24.1% and 20.7% had sexual activity within a month period as investigated via the EPIC and original questionnaire, respectively. However, 29.7% of all those who reported sexual activity rate reported “about once every 2?months to a year,” as shown in the original questionnaire. Regarding sexual function as addressed through EPIC, no results within that questionnaire’s measure of sexual function showed significant differences among patients with a rate of actual sexual activity.

Conclusions: The present survey showed that more than quarter of preoperative middle-aged Japanese prostate cancer patients surveyed had actual sexual activity, though not within the preceding 4?weeks. To precisely evaluate sexual function of middle-aged Japanese patients, it is necessary to consider actual sexual activity.     

Ecological studies on a dragonfly,Nannophya pygmaea ramber (Odonata: Libellulidae) I. seasonal changes of adult population and its distribution in a habitat

Summary Adult population of a dragonflyNannophya pygmaea Ramber inhabited in a damp ground was investigated with mark-and-recapture method in 1975. The following results about the seasonal changes of the population size and distribution in the habitat were obtained. Adults emerged from late May to mid August. The number of the adults was most abundant in early June, but that of matured males in early July. From the recapture data, the estimate of daily survival rate was 0.82, and the length of immature stage in males was estimated as 5 days or so. Total number of post-teneral adults emerged in the habitat was estimated as about 9,000. The mean crowding-mean density regression method was applied for the analysis of the distribution pattern of the adults. Matured males showed a spaced-out distribution, while females and immatured males distributed themselves rather aggregatively. Such a distribution pattern of the matured male would be attributed to their territorial behaviour. The territorial behaviour was considered to force the matured males to extend the distribution area in July when they were most abundant. From the above-mentioned results and some observations, the meaning of the territoriality in this species was discussed.     

Nectar secretion pattern of the dish-shaped flower,Cayratia japonica (Vitaceae), and nectar utilization patterns by insect visitors

Summary We studied the relationship between the diurnal nectar secretion pattern of flowers ofCayratia japonica and insect visiting patterns to these flowers. Flower morphology ofC. japonica changed greatly for about 12 hours after flower-opening and the maximum duration of nectar secretion was 2 days. The nectar volume peaked at 11∶00 and 15∶00, and declined at night and at 13∶00 regardless of time elapsed after flower-opening. The nectar volume at the two peaks was, on average, 0.25 μl on bagged inflorescences and 0.1μl on unbagged inflorescences (both, sugar concentration=60%). The flower secreted nectar compensatory when the nectar was removed. This means that insects consume more nectar than the difference of nectar volume between bagged and unbagged flowers. Apis cerana is a primary visitor of this flower, and was the only species for which we confirmed pollen on the body, among many species of flower visiting insects to this flower.Apis cerana visited intensively at the two peaks of nectar secretion. Visits of the other insects were rather constant or intensive only when there was no nectar secretion. Thus flowers ofC. japonica with morphologically unprotected nectaries may increase likelihood that their nectar is used by certain pollinators, by controlling the nectar secretion time in day. In this study the pattern of nectar secretion allowedA. cerana maximum harvest of nectar. Contribution to the ecological and bioeconomoical studies of the pollinator community in Kyoto I.     

Accumulation of phyllodulcin in sweet-leaf plants ofHydrangea serrata and its neutrality in the defence against a specialist leafmining herbivore

Among wild plants ofHydrangea serrata (Hydrangeaceae) in Japan, there are sweet plants whose leave contain a kind of isocoumarin, phyllodulcin, which happens to be 350 times as sweet as sucrose to the human tongue. In a primary beech forest in Ashu, Kyoto, the spatial distribution of sweet plants and temporal and the spatial distribution of phyllodulcin within and among plants were investigated using a high performance liquid chromatograph. The distribution of sweet plants was confined within a valley and was parapatric with non-sweet plants. A plant's characteristic phyllodulcin accumulation did not change, even when transplanted into the different habitats. The phyllodulcin content of the sweet plants varied greatly among plants, and the population mean peaked in July when the plants flowered. Within a plant, phyllodulcin content was elevated by partial defoliation. We examined the possible effect of phyllodulcin on herbivory by a specialist leafmining herbivore,Antispila hydrangifoliella (Lepidoptera: Heliozelidae). We transplanted sweet and nonsweet plants reciprocally between their original habitats, excluded attacks by parasitoids, and compared performance of the leafminer. Leafminer colonization and larval survivorship on transplanted andin situ plants was not significantly different between sites. The fact that accumulation of phyllodulcin did not augment a defensive function, at least against herbivory by the leafminer, and the sporadic distribution of phyllodulcin-accumulating plants, suggest that the genotypes synthesizing phyllodulcin emerged independently at separate localities by mutation, and that the genotypes are almost adaptively neutral in defence against the specialist herbivore.     

A note on current research of immigrant groups in Japan

"This article seeks to present a statistical summary of Japan's immigrant groups and a review of current research on these groups, with the aim of discovering what crucial ethnic problems are faced both by the immigrant groups and the Japanese people themselves."     

A remark on self-similar processes with stationary increments

The upper bound of the parameter of self-similar processes with stationary increments is given in terms of the moment condition.     

Second-order properties of a two-stage fixed-size confidence region when the covariance matrix has a structure

We study second-order properties of a two-stage fixed -size confidence region for estimating the mean vector μ in the N_p(μ∑) population when some auxiliary information about the structure of ∑ is available. In the case when we do not have such nrior information regarding ∑. Mukhopauiiyay (199/ ) de rived second-order properties of the classical two stage fixed-size confidence region, when properly modified. It was assumed that the maximum latent root of ∑ was simple and bounded below by a known positive number. In this paper we allow the maximum latent root to have general multiplicity for the verification of the second order properties of the two-stage procedure incorpo rating ∑'s structural information. We also maintain the nominal confidence coefficient.