Gift-giving in romantic couples serves as a commitment signal: Relational mobility is associated with more frequent gift-giving

The present study explored why married couples periodically exchange gifts. Based on the commitment signal hypothesis, we tested whether relational mobility, which was operationalized as divorce rate in Study 1 and relational opportunities in Study 2, is positively correlated with the frequency of gift exchanges among married couples. In Study 1, we found that married couples in the U.S., which is associated with a relatively high divorce rate, were more likely to give and receive gifts to and from their partners than those in Japan, which is associated with a relatively low divorce rate. This societal difference, in contrast, was not observed among unmarried couples, who were still developing their relationship (and thus, partner changes could frequently happen regardless of the country-level divorce rate). Study 2, a secondary analysis of extant survey data, revealed that Japanese married couples who have more relational opportunities more frequently engage in gift exchanges than those who do not. Together, these results support our hypothesis that periodical gift exchanges work as commitment signals among married couples.     

Stimulation of DNA-mediated transformation by UV irradiation of recipient (mouse FM3A) cells

DNA-mediated transformation for thymidine autotrophs (Tk+) was stimulated severalfold when the recipient (mouse FM3A) (Tk-) cells were preirradiated by UV light. The effect was most prominently seen with the cells irradiated 12-16 hours prior to DNA addition. A similar stimulatory effect was observed when the cells were treated with novobiocin or mitomycin C. The effect, however, was blocked when cycloheximide was present during postirradiation period, suggesting that de novo protein synthesis is required for producing the effect. Most of the Tk+ transformants arised from the UV-irradiated cells carried the donor DNA sequences in their chromosomes.     

Timing of DNA replication during the meiotic process in monokaryotic basidiocarps of Coprinus macrorhizus

By applying the method of fluorescent microscopy to propidium iodide stained cells, change in the relative amount of DNA in a basidium was examined during the meiotic process in Coprinus macrorhizus. In the monokaryotic basidiocarp of the mutant strain Fis^c, mitotic DNA replication was first induced soon after a 3h-illumination period on the 10th day of culture, and subsequently meiotic DNA replication occurred after karyogamy.     

Immunogenetic studies on wild pigs in Japan

The variations of blood groups in the two subspecies of wild pigs in Japan ( Sus scrofa leucomystax and S.s. riukiuarus ) were investigated by serological techniques. S.s. leucomystax showed polymorphism in the A and F systems. S.s. riukiuanus showed a little polymorphism in the F system only. As a whole, there was a great similarity in erythrocyte antigen structures of both S.s. leucomystax and S.s. riukiuanus. In comparison with the erythrocyte antigen frequenties of wild pigs in the Eurasian Continent reported by other workers, East-West geographical clines in the frequencies of Ee, Fa, Ga, Ka, Kb and Lh antigens were clearly observed. From the results of investigation on genetic similarities among seven wild pig populations, it was made clear that the two Japanese strains were very close and were closer to Far Eastern (S.s. ussuricus) than Middle Asian (S.s. nigripes) , Transcausian (S.s. attila) and European pigs ( S.s. ferus ).     

Annual and daily activity rhythms of loathes in an irrigation creek and ditches around paddy fields

Synopsis This study deals with the daily activity rhythm and its change in a loath,Misgurnus anguillicaudatus, by season and age. We set traps in an irrigation creek and ditches around the paddy fields near Nara city every month for 2 years. The fish appeared in spring, declined in early summer, and increased in mid-summer again, and disappeared in late autumn. The number of fish captured at night was greater than that during the daytime in summer. There were some differences in the daily rhythms by sex and age. Nocturnal activities of males and immatures were more prominent than those of females. Younger generation were more nocturnally active than elders in summer. Changes in the daily activity rhythms of the loath are possibly adaptive to unstable environments around paddy fields.     

Effects of duration and intensity of illumination on several parameters of the chick eye

Effects of duration and intensity of illumination on eye weight, eye diameter, corneal diameter and anterior chamber depth were investigated in Warren chicks. Increase in eye weight was observed in continuous light, LD 22:2 and continuous darkness. Shallow anterior chamber and small corneal diameter were observed in continuous light and LD 22:2, but not in continuous darkness. Continuous bright light (5000 lux) did not induce an increase in the eye weight but instead induced severe lesions in the anterior segment of the eye. Injection of corticosterone (500 micrograms) induced a significant reduction in the eye weight.     

Pheochromocytoma associated with adrenocortical adenoma: case report and literature review

The case of a 60-year-old woman with pheochromocytoma and concomitant adrenocortical adenoma in the same gland is presented. She complained of episodic headache, palpitation, nausea, vomiting and sweating. Physical examination revealed that the patient has generalized obesity, wet skin and paroxysmal hypertension, but no signs of Cushing's syndrome. Elevated levels of urinary noradrenaline, adrenaline and total metanephrine were sequentially observed. In addition, urinary 17-OHCS was also slightly elevated, but plasma cortisol was normal and suppressed after oral administration of 0.5 mg of dexamethasone. Abdominal echography and CT scanning demonstrated a left adrenal tumor, which took up both 131I-meta-iodobenzylguanidine and 75Se-scintadoren in the same region. A left adrenalectomy was performed and the tumor was found to consist of two parts, pheochromocytoma (2.5 X 2.5 X 2.5 cm) and cortical adenoma (2.5 X 3 X 5 cm). A total of 23 reported cases showing evidence of hyperfunction of the adrenal cortex and the medulla were noted. So far as we know, this patient was the second case of pheochromocytoma with adrenocortical adenoma in Japan.     

An intracellular factor which affects erythroid differentiation in mouse Friend cells

When permeabilized Friend cells, which had been briefly treated by DMSO, were exposed to cell-free extracts from UV irradiated cells, a small but significant number of the cells became reactive to benzidine, a characteristic of erythroid differentiation. The activity in the extracts was apparently induced following UV irradiation, reaching a maximum 25 to 30 h after irradiation. Although a similar activity was detected in the extract from mitomycin C treated cells, little activity was detected in the extract from cells treated with DMSO, a potent erythroid inducing agent. The induction of the active factor by UV irradiation was not specific of Friend cells since similar inducing activities were detected in the extract from non-erythroid murine cells irradiated by UV. The active factor in the extract seems to be a protein, judged from its heat sensitivity and high molecular weight. Significance of this finding in relation to cellular differentiation and DNA damage is discussed.