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81.
Michio Yoneda Yutaka Kurita Daiji Kitagawa Masaki Ito Takeshi Tomiyama Tomoaki Goto Kiyotaka Takahashi 《Fisheries Science》2007,73(3):585-592
ABSTRACT: This study examined age and growth of Japanese flounder Paralichthys olivaceus off the Pacific coast of northern Japan, and determined whether the growth patterns of male and female fish in northern (40–41°N) and southern (37–38°15'N) waters differ. In total 8095 specimens were collected between January 1999 and December 2005. Zonation consisting of opaque and translucent bands on the otolith was evident. Within each opaque band a thin and clear check (ring mark) was observed in all specimens examined. Monthly change in the frequency of appearance of a ring mark on the outer margin of the otolith indicates that ring marks form between July and August. The von Bertalanffy growth model showed a sexual dimorphism in growth, as females grew faster and reached a larger size than males. The growth patterns obtained by tracking the observed total length for monthly collections showed a rapid increase in total length between August and October. Spatial variation in the growth pattern of male and female fish between northern and southern waters was evident, as southern fish were significantly larger than northern counterparts during 1.25–3.00 years post hatch. 相似文献
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83.
Hua Jiang Tomoaki Saiki Kenji Watanabe Hiromu Kawakita Mamoru Sato 《Journal of General Plant Pathology》2005,71(5):370-372
Mulberry dwarf (MD) phytoplasma was surveyed for its presence in presumably nonvector insects (two species of leafhoppers, thrips, and spider mites) collected from MD-diseased trees. MD phytoplasma was found in all species by nested polymerase chain reaction using specific primers for the 16Sr I-group phytoplasma. By electron microscopy, MD phytoplasma was observed in the salivary glands of the leafhopper Tautoneura mori Matsumura. In addition, the vector ability of T. mori was verified through bioassay; 25% of seedlings inoculated with infective leafhoppers had MD symptoms, suggesting that T. mori may act as a vector of MD phytoplasma in fields in some cases. 相似文献
84.
Koji KAGEYAMA Tomoaki AOYAGI Rumi SUNOUCHI Hirokazu FUKUI 《Journal of General Plant Pathology》2002,68(1):15-20
Miniature roses growing in an ebb-and-flow watering system developed dieback during the summer growing season of 1996 in Gifu
Prefecture. The main diagnostic symptoms were chlorosis of leaf followed by blight, and a brown, water-soaked root rot followed
by dieback. Pythium isolates were recovered from the rotted root. The isolates form proliferous ellipsoidal papillate sporangia, spherical smooth
oogonia, elongate antheridia, and aplerotic oospores. The optimum temperature for hyphal growth was 35°C with a growth rate
of 34 mm/24 hr. Optimum temperature of zoospore formation (25-30°C) was lower than that of mycelial growth, and zoospores
were produced even at 10°C. The isolates were identified as P. helicoides on the basis of these characteristics. In pathogenicity tests disease severity was highest at the highest tested temperature
(35°C) at which the disease naturally occurred in summer. Four days after inoculation, the leaves turned yellow and the roots
had a water-soaked rot, followed by leaf blight and root dieback after 7 days. The disease transmission test showed that diseased
plants were found throughout the bench after 10 days.
Received 4 July 2001/ Accepted in revised form 10 October 2001 相似文献
85.
Yoshihiro OHTSU Maitree PROMMINTARA Seiichi OKUDA Tomoaki GOTO Takeshi KANO Kazuo NAKASHIMA Meisaku KOIZUMI Jun IMADA Koji KAWASHIMA 《Journal of General Plant Pathology》2002,68(4):372-377
We aimed to improve the purification of citrus Huanglongbing (greening) bacterium (HB), Candidatus Liberobacter asiaticum and to produce an antiserum against HB. Periwinkle plants Catharantus roseum L. graft-inoculated with HB were used to produce an antiserum. All young leaves of new shoots incubated at 20–25°C and 25–30°C,
a few mature leaves incubated at 20–25°C, and all mature leaves incubated first at 25–30°C and later transferred to 20–25°C
developed yellowing symptoms and were then used to prepare immunogen. The HB was partially purified from these leaves by an
improved method that included a macerating enzyme treatment of the midribs of infected leaves and homogenization of infected
phloem sieve tissues. An antiserum raised against partially purified HB reacted clearly at a dilution of 1/16 with HB-infected
citrus extract prepared at a concentration of 40 times, but did not react with healthy or tristeza virus-infected citrus extract
in microprecipitin tests.
Received 23 August 2002/ Accepted in revised form 4 December 2002 相似文献
86.
Different prostaglandin F2α secretion in response to oxytocin injection between pregnant and non‐pregnant cows: effect of the day of oxytocin challenge test for determining the difference 
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下载免费PDF全文 Tomoaki Kubo Kosuke Iga Naoki Fukuju Keiichiro Kizaki Takeshi Osawa Yoshiaki Izaike Toru Takahashi 《Animal Science Journal》2018,89(2):332-339
The present study was conducted to determine the difference in plasma prostaglandin F2α metabolite concentrations following oxytocin (OT) challenge between pregnant and non‐pregnant cows. Experiment 1: cows were subjected to the OT challenge test on days 12, 14 or 16 (day of estrus = day 0) with or without prior insemination and plasma 13,14‐dihydro‐15‐keto prostaglandin F2α (PGFM) concentrations were measured from ?30 to 180 min after OT injection. On day 16, the increment of plasma PGFM concentrations in response to OT injection was significantly smaller in pregnant than that in cyclic cows. On days 12 and 14, there was little OT‐induced PGFM secretion and no difference in PGFM increase between the pregnant and cyclic cows. Experiment 2: cows were inseminated on day 0 and subjected to the OT challenge test on day 16. Cows were classified into non‐pregnant/early embryonic death (NP/EED), late embryonic death (LED) and pregnant (PREG) groups. The increment of PGFM concentrations in response to OT injection was less in both PREG and LED groups than that in the NP/EED group. In conclusion, plasma PGFM secretion induced by OT is suggested as the base of pregnancy diagnosis prior to returning estrus in cows. 相似文献
87.
Ohyama K Ohta M Sano T Sato K Nakagomi Y Shimura Y Yamano Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(6):619-625
We have analyzed the effects of low-dose transplacental and lactational exposure of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on gene expression relating to the dioxin and sexual hormone cascade, and demonstrated the effects on testicular growth and sexual maturation in male offspring rats. TCDD (10 ng/kg) was administered to dams on Days 7 and 14 of gestation, and on Days 0, 7 and 14 after delivery. Gene expression of cytochrome P450 family 1 subfamily A polypeptide 1 (CYP1A1) in the liver of 17-day-old rats was significantly increased compared with controls. Furthermore, expression of estrogen receptors (ER)alpha and ERbeta was significantly increased at 17 and 42 days old, respectively in the testis of TCDD-administered rats compared with controls. Although testicular weight and the seminiferous tubule diameter were increased in 17-day-old rats, there was no difference in the number of germ cells between TCDD-treated and control animals. The expressions of androgen receptor and inhibin subunit genes were not significantly changed. These findings suggest that low-dose exposure of TCDD leads to unusual development of the testis by perturbation of steroid hormone homeostasis. 相似文献
88.
Role of sulphide reduction by magnesium hydroxide on the sediment of the eutrophic closed bay 下载免费PDF全文
下载免费PDF全文 Dong Xia Katsumi Okada Kunio Watanabe Yukiko Miura Rameshprabu Ramaraj Niwooti Wangchai Kanda Wangchai Tomoaki Itayama 《Aquaculture Research》2018,49(1):462-470
This study was focused on the effect of magnesium hydroxide (Mg(OH)2) for improving the sediment of aquaculture field and eutrophic closed estuaries. Sediment samples were collected from Omura Bay, Nagasaki, Japan. The change in pH, acid volatile sulphides (AVS) and dissolved organic carbon (DOC) in interstitial water of the sediment samples were measured before and after 20‐day incubation under the condition of overlapping seawater at 25°C with 0.3–0.4 mg/L of dissolved oxygen (DO). Hydrogen sulphide (H2S) and the dsrA gene copy number of Grp3 sulphate‐reducing bacteria (SRB) in the sediment samples were also measured at 7‐day incubation under the same condition. The pH of Mg(OH)2 treatment group was significantly increased from 7.43 to 8.25; it was higher compared to the control group which pH was maintained around 7.6. Meanwhile, the AVS content of Mg(OH)2 treatment group was significantly reduced and the value was lower than the control group after the 20‐day incubation. Each concentration of interstitial water DOC in the treatment group and the control group increased after the incubation from initial value of 15.4–40.1 and 29.0 mg/L respectively. Furthermore, simultaneous decrease in H2S and the dsrA gene copy number of Grp3 SRB was observed at the end of the 7‐day incubation by adding Mg(OH)2. It is concluded that the loss of activity of SRB was strongly related to the decrease in sulphide (H2S and AVS) and the increase in DOC was due to the alkalization of the sediment by adding Mg(OH)2. 相似文献
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90.
Wataru Aoyama Shinya Sasaki Shigeki Matsumura Thoru Mitsunaga Hirofumi Hirai Yuji Tsutsumi Tomoaki Nishida 《Journal of Wood Science》2002,48(6):497-504
Two peroxidases, CWPO-A and CWPO-C, were isolated from the cell walls of poplar (Populus alba L.) callus culture. The cationic CWPO-C showed a strong preference for sinapyl alcohol over coniferyl alcohol as substrate. Thus, the monolignol utilization of CWPO-C is unique compared with other peroxidases, including anionic CWPO-A and horseradish peroxidase (HRP). CWPO-C polymerized oligomeric sinapyl alcohol (S-oligo) and sinapyl alcohol, producing a polymer of greater molecular weight. In contrast, HRP, which is specific to coniferyl alcohol, produced sinapyl alcohol dimers, rather than catalyzing polymerization. Adding coniferyl alcohol as a radical mediator in the HRP-mediated reaction did not result in S-oligo polymerization. This report shows that CWPO-C is an isoenzyme specific to sinapyl alcohol that polymerizes oligomeric lignols. Its catalytic activity toward oligomeric lignols may be related to the lignification of angiosperm woody plant cell walls.Part of this study was presented at the 45th Lignin Symposium, Matsuyama, October 2000 相似文献