太湖流域新石器时期的古稻作

对太湖流域６个新石器时期遗址的１２８份土壤样本进行植物蛋白的定量和形态分析,就太湖流域新石器时期的古稻作进行初步探讨。植物蛋白石定量分析结果表明,太湖流域早在８０００（Ｂ．Ｐ．）年前就开始稻作生产,至６０００（Ｂ．Ｐ．）年前这一地区的稻作生产已相当普遍,并得到了较快的发展,使太湖流域的稻作生产达到了一个较高的水平。根据水稻蛋白石形态分析结果,当时所栽培的稻种类型均属粳稻,但不同地区、不同时期的古稻种有一定差异。     

Malignant stromal cell tumor of the spleen in a WBN/Kob rat

Primary splenic stromal tumors have rarely been reported in rodents. We report the case of a 90-week-old male WBN/Kob rat with a nodular demarcated mass in the spleen, which was kept as a non-treated animal in a long-term animal study. Histopathology revealed round to short spindle-shaped tumor cells arranged in a solid growth pattern. Invasive growth, anisokaryosis, and high mitotic activity (46 per 10 high-power fields [2.37 mm²]) were observed to be multifocal, but most tumor cells showed mild nuclear pleomorphism. The pattern of silver impregnation corresponded to that of the marginal zone of the red pulp. Immunohistochemistry revealed that the tumor cells were double positive for fascin and desmin and focally positive for Iba-1 and OX-6 expression. These characteristics were similar to those observed in fibroblastic reticular cells and dendritic cells in the marginal zone of the red pulp. These findings suggest that the malignant stromal cell tumor of the spleen in this case had characteristics of both fibroblastic reticular cells and dendritic cells.     

Spawning frequency of the Tsushima Current subpopulation of chub mackerel <Emphasis Type="Italic">Scomber japonicus</Emphasis> off Kyushu,Japan

Female Japanese chub mackerel Scomber japonicus of the Tsushima Current subpopulation were collected during the spawning season from March to May 2001. A total of 137 adult females were caught between midnight and daybreak. A considerable number of fish displayed new postovulatory follicles (POF), whereas there was no evidence of germinal vesicle breakdown or hydrated oocytes in any of the fish collected. This suggests a daily spawning synchronicity toward midnight. To estimate the spawning frequency (S), the female reproductive state was classified into four criteria based on the degenerative stage of the POFs and the developmental stage of the oocytes. To stage the POFs according to age and determine the stage duration, ovaries from S. japonicus were induced to spawn in the laboratory and were sampled 0–72 h after ovulation at appropriate intervals. The average S, which is evaluated from four different indices, was 16.9%, corresponding to the average female chub mackerel spawned every 5.9 days (8.5 times) during the 50 days.     

Time course of final oocyte maturation and ovulation in chub mackerel <Emphasis Type="Italic">Scomber japonicus</Emphasis> induced by hCG and GnRHa

Abstract:   The question of whether the ovulation and spawning time in chub mackerel Scomber japonicus is entrained by a circadian rhythm was raised by our previous experiments. Further questions were also raised about whether the time course of human chorionic gonadotropin (hCG)-induced final oocyte maturation (FOM) and ovulation reflected the natural time course induced by endogeneous pituitary gonadotropin (GtH). To address these questions, hCG and gonadotropin-releasing hormone analog (GnRHa) were administered at two 'opposite' times, 14:00 and 02:00 hours, and the time courses of FOM and ovulation were compared. When hCG was injected, ovulation occurred 33 h post-injection in both groups, regardless of the timing of the hCG injection. The timing of ovulation in chub mackerel depends on the timing of hCG injection, but apparently not on circadian rhythms. When GnRHa was injected, ovulation began at 36 h post-injection of GnRHa, regardless of the timing of injection. These results indicate that the time course of FOM and ovulation in the chub mackerel followed a similar pattern whether stimulated by hCG injection or spontaneous luteinizing hormone (LH) surge because GnRHa induces the secretion of endogenous GtH (primarily LH) from the fish pituitary. Thus, it is concluded that the time course of hCG-induced FOM and ovulation in chub mackerel follows the natural time course induced by endogenous pituitary LH.     

Development and evaluation of a support system for forest education

Field education programs have been conducted throughout the world because learning through experience is an important process in environmental and forest education. We developed a support system for forest education that consists mainly of a Global Positioning System (GPS) and personal digital assistant (PDA). Moreover, field experiments were conducted to evaluate educational efficacy as well as usability of the developed system. Through a post-questionnaire the developed system was highly evaluated in terms of educational efficacy and enjoyment. On the other hand, the questionnaire revealed the need for technical improvements. For example, the drawing function, which involves the use of a stylus pen, was the most poorly evaluated because a drawing could not be partially erased as with an eraser and representation was not sufficiently accurate. In addition, positions where information on nature appeared were sometimes inaccurate due to positional errors caused by using the autonomous GPS. Some participants answered that walking with the developed system was also troublesome due to its shape and size. In fact, they did not feel comfortable about the cables connecting the GPS to the PDA and GPS to its antenna. Although there were some problems with the system, we believe that the field education program was successful because 95% of the participants answered that they would join a similar program again.     

Virtual forest: design and evaluation of a walk-through system for forest education

Forest education is generally conducted in a real forest to provide learners a direct experience with reality. However, often it is not easy to participate in forest education programs carried out in remote places due to distance, limited time, or economic or physical restrictions. Therefore, we developed a walk-through system for forest education in a virtual forest and evaluated its educational efficacy as well as usability through indoor experiments. The virtual forest was constructed with omnidirectional images taken in a forest using a digital camera with an omnidirectional vision sensor. The results of the postquestionnaire showed that the developed system was highly evaluated by the participants in the experiments in terms of educational efficacy and enjoyment. Also, comparison of results of prequestionnaire and postquestionnaire showed that it had educational value. On the other hand, some technical problems in the developed system were revealed. For example, 45.0% of the participants answered that the walk-through in the virtual forest did not proceed with sufficient smoothness, and encountered unexpected slowdowns and stops. In addition, image quality was not high enough to identify small objects in the virtual forest. Regardless of these problems, we believe that the computer-based forest education was successful because 88.3% of the participants answered that they would like to join a similar program again and 90.0% answered that they would like to visit the real forest that the virtual forest imitated.     

Evaluation of Salmonella enterica serovar Typhimurium and Choleraesuis slyA mutant strains for use in live attenuated oral vaccines

SlyA protein plays a key role in virulence in Salmonella enterica. In this study, we evaluated the ability of the slyA mutant strain of S. enterica serovar Choleraesuis (S. choleraesuis) to protect against swine salmonellosis. Using a murine model infected with S. enterica serovar Typhimurium (S. typhimurium), we showed that the Salmonella strain with a deletion of slyA could be used as a highly immunogenic, effective and safe vaccine in mice. Based on these data, a slyA mutant of S. enterica serovar Choleraesuis strain RF-1 was constructed, and the ability of this mutant to protect immunized pigs from S. choleraesuis infection was examined. As with the S. typhimurium slyA mutant, immunization of pigs with the S. choleraesuis slyA mutant strain provided significant protection against subsequent challenge by the wild-type RF-1. These results demonstrate that SlyA is a potential target in the development of a novel live attenuated vaccine against S. enterica.     

Screening for proteinuria in cats using a conventional dipstick test after removal of cauxin from urine with a Lens culinaris agglutinin lectin tip

Proteinuria is an important indicator of urinary tract disease and urine dipsticks are simple and sensitive tools to screen for this marker. However, the use of dipsticks to screen for proteinuria may not be appropriate in cats, since cauxin, a 70 kDa glycoprotein, is secreted by the kidneys in clinically normal animals of this species. To circumvent this problem, a Lens culinaris agglutinin (LCA) lectin tip was developed to remove cauxin from feline urine, followed by conventional urine dipstick testing for proteinuria. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS–PAGE) with Coomassie brilliant blue R-250 staining indicated that >90% cauxin in the urine of 13 clinically normal cats was trapped by the LCA lectin tip, so that the dipstick protein ‘score’ changed from ‘positive’ (?30 mg/dL) for untreated urine to ‘negative’ (?10 mg/dL) for lectin tip-treated urine. In contrast, SDS–PAGE indicated that lectin tip-treated samples from 20 animals with renal disease contained high concentrations of albumin and low-molecular weight proteins; dipstick testing of lectin tip-treated urine resulted in a consistently positive protein score. The accuracy of the dipstick method for detecting cats with abnormal proteinuria is enhanced if dipsticks are used with urine samples that have first been passed through the LCA lectin tip.