排序方式: 共有24条查询结果,搜索用时 31 毫秒
1.
SUMMARY: Behavioral experiments concerning a releaser pheromone in the urine of female rainbow trout were performed using immature fish administered orally with 17α-methyltestosterone (MT) during the non-spawning season. The urine was collected by catheter. The frequency of entries of test fish was recorded in each channel scented by test and control solutions in a Y-maze trough. The behavior of both MT-treated and control fish demonstrated that they could not discriminate the differences between distilled and environmental water as control solutions. There was also no difference between MT-treated and control fish when distilled and environmental water were introduced. The MT-treated immature fish were attracted to the channel scented by ovulated female urine. Neither coelomic fluid nor the immature female urine had any effect on the behavioral responses of MT-treated fish, while immature control fish had no preference for the urine of ovulated females. These results suggest in rainbow trout that ovulated female urine contains a releaser pheromone to attract mature males, and that androgens are involved in the sensory mechanisms detecting the releaser pheromone in fish. 相似文献
2.
为监测较大区域内甘蔗产量及含糖量的时间、空间变化情况,了解地区、环境及土壤成分与甘蔗含糖量的关系,为甘蔗栽培提供指导,以日本琉球群岛南大东岛甘蔗栽培区为对象,用NIR方法测定甘蔗含糖量及其他成分含量,采用GIS技术建立地块位置、甘蔗产量、含糖量及P、K含量和土壤K含量数据库。在此基础上,建立3个栽培年度甘蔗含糖量、单产与甘蔗汁P、K含量的空间分布图,发现甘蔗含糖量与降水量及种植区水环境密切相关。对甘蔗含糖量及P、K含量和土壤K含量的相关分析表明,甘蔗含糖量与甘蔗汁P含量呈正相关,而与甘蔗汁和土壤K含量均呈负相关。 相似文献
3.
4.
H. Yambe A. Munakata S. Kitamura K. Aida N. Fusetani 《Fish physiology and biochemistry》2003,28(1-4):279-280
We investigated the optimum term of 17α-methyltestosterone (MT) -treatment for behavioral test and changes of plasma sex steroids levels in MT-treated immature male masu salmon, Oncorhynchus masou parr. Behavioral responses of MT-treated fish to the urine of ovulated or immature females were observed in an experimental trough. After 5 min of behavioral tests, plasma sex steroids levels were measured by RIAs. MT-treated fish showed specific behavioral responses to the ovulated female urine. MT-treated fish without exposure to the urine showed no clear changes in plasma 17,20β-dihydroxy-4-pregnene-3-one (DHP). However, plasma DHP in MT-treated fish increased when they were exposed to the urine. 相似文献
5.
Sakagami N Umeki H Nishino O Uchiyama H Ichikawa K Takeshita K Kaneko E Akiyama K Kobayashi S Tamada H 《The Journal of reproduction and development》2012,58(1):140-146
The objective of this study was to examine whether high concentrations of epidermal growth factor (EGF) and/or insulin-like growth factor I (IGF-I) would have a beneficial effect on bovine embryo development in vitro and to obtain normal calves by using an ovum pick up method and embryo culture in a chemically defined medium. When compared with controls, EGF (100 or 200 ng/ml) or IGF-I (50 or 100 ng/ml) significantly increased the rate of embryos that developed into blastocysts during an 8-day culture after the in vitro fertilization of oocytes obtained from ovaries from a slaughterhouse. IGF-I induced a dose-dependent increase in cell number in both the inner cell mass and the trophectoderm, whereas EGF stimulated proliferation only in the inner cell mass. A combination of EGF (100 ng/ml) and IGF-I (50 ng/ml) produced an additive effect, and embryos developed into blastocysts at a comparatively high rate (27.9%) compared with controls (12.0%). A similar rate of development was achieved using a combination of EGF and IGF-I in the culture of embryos following ovum pick up by ultrasound-guided transvaginal follicular aspiration and in vitro fertilization, and 5 blastocysts that developed after the culture were transferred into uteri; two embryos implanted, and normal calves were born. These results suggest that the combined use of EGF and IGF-I makes bovine embryo culture in a chemically defined medium a practical and useful procedure for producing blastocysts, and its application to embryo culture following ovum pick up and in vitro fertilization could be useful for producing normal calves. 相似文献
6.
7.
Powdery Mildew of Prairie Gentian: Characteristics,Molecular Phylogeny and Pathogenicity 总被引:3,自引:0,他引:3
OKAMOTO Jun LIMKAISANG Saranya NOJIMA Hidenobu TAKAMATSU Susumu 《Journal of General Plant Pathology》2002,68(3):200-207
In March 1999, we found prairie gentian (Eustoma grandiflorum) infected with powdery mildew in a greenhouse in Oita Prefecture, Japan. Morphological observation revealed that the causal
fungus belongs to the mitosporic genus Oidium subgenus Pseudoidium [teleomorph: Erysiphe sensu Braun and Takamatsu (2000)]. Precise taxonomic position of the fungus, however, is uncertain due to lack of the perfect stage.
We determined the nucleotide sequence of the rDNA ITS region of the fungus. Comparison of the sequence with those obtained
from DNA databases of this fungal group revealed that the sequence is identical to those of powdery mildews from garden four-o'clock
(Mirabilis jalapa) and broad bean (Vicia faba). Inoculation of an isolate from garden four-o'clock caused mildew on prairie gentian and broad bean, suggesting that the
prairie gentian mildew originates from garden four-o'clock or broad bean. Molecular phylogenetic analysis indicated a close
relationship of this fungus to Erysiphe baeumleri on Vicia spp. and E. trifolii on Trifolium pratense. From these results, we propose that prairie gentian mildew diverged from a Fabaceae-parasitic ancestor.
Received 14 March 2002/ Accepted in revised form 28 May 2002 相似文献
8.
Katsuhiko Tsuruoka Takami Kurahara Hidenobu Kanamaru Hideyuki Takahashi Takafumi Gotoh 《Animal Science Journal》2019,90(5):637-648
This study evaluated the effects of condensed barley distillers soluble (CBDS) on growth rate, rumen fermentation, plasma metabolite, and myofiber properties, and gene expression related to metabolism in the skeletal muscles of Japanese Black calves, compared with soybean meal and corn. Twenty‐four calves were divided into four groups: fed 5% CBDS based on the hay dry matter weight (low CBDS) and fed soybean meal and corn at the same nutrition level (control); and fed 15% CBDS based on the hay dry matter weight (high CBDS) and fed soybean meal and corn at the same nutrition level (high soy). The daily gain was larger in the low (p = 0.08) and high (p < 0.05) CBDS groups compared with the control group. In the CBDS‐fed groups, plasma β‐hydroxybutyric acid concentrations were significantly higher at 6 months of age (p < 0.05), the percentage of type I myofibers was significantly lower and their diameters were significantly larger at 9 months of age (p < 0.05), and carnitine palmitoyltransferase 1b mRNA expression was significantly lower (p < 0.05) and citrate synthase mRNA expression tended to be lower (low; p = 0.06, high; p = 0.05) compared with control group. Thus, feeding CBDS promotes growth and leads to animals with more glycolytic and less oxidative muscle metabolism. 相似文献
9.
Toyozo Sato Taturo Muta Yukihisa Imamura Hidenobu Nojima Jouji Moriwaki Yukio Yaguchi 《Journal of General Plant Pathology》2005,71(5):380-383
Anthracnose of Japanese radish found in Kagoshima and Miyazaki prefectures was demonstrated to be caused by Colletotrichum dematium based on inoculation experiments and morphological and molecular identification of the pathogenic fungus. Although symptoms of Japanese radish anthracnose caused by Colletotrichum higginsianum were similar to those caused by C. dematium, damage by the latter pathogen was more severe than that by C. higginsianum. 相似文献
10.
Abstract The phosphate sorption (P sor) capacity of soils increased when the soils were reduced (Willet and Higgins, Aust. J. Soil Res., 16, 319–326, 1978). The present study aimed at the elucidation of this mechanism using Na2S2O4 and 5 different soils. The P sor of the 5 soils increased with the addition of a small amount of Na2S2O4. Fe(II) was released from the soils with the addition of the same small amount of Na2S2O4. Furthermore, when the amount of FeCl2 corresponding to the amount of Fe(II) released along with the small amount of Na2S2O4 was added, the P sor of the soil increased. However, the P sor of the lowland soils, of which the hydrous Fe oxide content was lower than the others, decreased when the amount of Na2S2O4 addition was increased up to 150–200 g kg?1. Based on these results, the following process is inferred for the increase in the P sor of the soils when they are reduced. Hydrous Fe oxide in soil takes the form of very fine, high-density particles and reacts with P mainly on their surface. When a small amount of Na2S2O4 is added, the hydrous Fe oxide is partially reduced, dissolved and finally re-precipitates with P by oxidation with O2 from the air during the experiment. 相似文献