Assessing sexual maturity of feminized Japanese eel Anguilla japonica by measuring eye size     

Akihiro Okamura  Hideo P. Oka  Noriyuki Horie  Tomoko Utoh  Yoshiaki Yamada  Naomi Mikawa  Satoru Tanaka  Katsumi Tsukamoto 《Aquaculture International》2009,17(1):91-99

For efficient production of Japanese eel Anguilla japonica eggs, knowledge of the status of the sexual maturity of potential broodstock females is important because this status directly influences the time required to produce mature eggs by successive hormone doses. Here we apply an eye index (relative eye size) to evaluate the gonadal status of feminized A. japonica, which were induced by administration of estradiol-17β. Examination of gonad somatic and eye indexes of 267 feminized eels, cultivated for 12–56 months, revealed a significant correlation between these two indexes. Artificial maturation of 35 feminized eels showed that the number of hormone injections administered before ovulation was significantly lower as the eye index score increased, indicating availability of this noninvasive method of predicting sexual maturity of feminized eel. There was no correlation between eye index and fertilization rate, hatching rate, or larval survival rate, suggesting that sexual maturity before hormonal treatment does not affect egg quality.  相似文献   

Monitoring cotton (<Emphasis Type="Italic">Gossypium hirsutum</Emphasis> L.) germination using ultrahigh-resolution UAS images     

Ruizhi?Chen  Tianxing?ChuEmail author  Juan?A.?Landivar  Chenghai?Yang  Murilo?M.?Maeda 《Precision Agriculture》2018,19(1):161-177

Examination of seed germination rate is of great importance for growers early in the season to determine the necessity for replanting their fields. The objective of this study was to explore the potential of using unmanned aircraft system (UAS)-based visible-band images to monitor and quantify the cotton germination process. A light-weight UAS platform was used, which carried a consumer-grade red, green, and blue camera stabilized by a built-in gimbal system. In order to obtain ultrahigh image resolution during the germination stage, the UAS platform was flown at an altitude of approximately 15–20 m above ground. By applying the structure-from-motion (SfM) algorithm, the images were rectified and orthographically mosaicked with a ground sampling distance of approximately 6–9 mm/pixel. A novel solution was then developed for calculating the average plant size and the number of germinated cotton plants according to the leaf polygons extracted from the orthomosaic images. By using the estimated number of germinated cotton plants, the plant density and the cumulative germination rate can also be estimated in a straightforward manner using field-specific parameters. An assessment of the proposed solution was conducted by comparing the estimated number of the germinated cotton plants against ground observation data collected from six cotton row segments. The results demonstrated that the average estimation accuracy achieved 88.6% in terms of identifying the number of the germinated cotton plants. The accuracy may be further improved if images with near infrared band are employed.  相似文献   

Ontogenetic changes of feeding habits of larval jack mackerel <Emphasis Type="Italic">Trachurus japonicus</Emphasis> in the Kuroshio frontal area of the southern East China Sea     

Yuuichi Hirota  Hitoshi Honda  Hideo Sakaji  Shinji Uehara  Tadafumi Ichikawa 《Fisheries Science》2016,82(4):573-583

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Biological control of potato scab and antibiosis by antagonistic Streptomyces sp. WoRs-501     

Yuki O. Kobayashi  Akira Kobayashi  Masayuki Maeda  Nobutaka Someya  Shigehito Takenaka 《Journal of General Plant Pathology》2015,81(6):439-448

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Molecular cloning of canine interleukin-31 and its expression in various tissues     

Takuya Mizuno  Satoshi Kanbayashi  Takumi Okawa  Sadatoshi Maeda  Masaru Okuda 《Veterinary immunology and immunopathology》2009,131(1-2):140-143

The newly discovered cytokine, interleukin-31 (IL-31), belongs to the short-chain cytokine group. It was reported that transgenic expression of IL-31-induced pruritus, similar to atopic dermatitis, in mice, further, excessive amounts of IL-31 was also expressed in the skin from human patients with atopic dermatitis as compared to that from normal people. In this study, canine IL-31 was molecularly cloned from concanavalin A-stimulated canine peripheral blood mononuclear cells (PBMCs), and its nucleotide sequence was determined. Canine IL-31 contains 4 alpha-helix structures characteristic of the IL-31 family, and the amino acid identity of canine IL-31 with those of human or mouse is 54% and 28%, respectively. Furthermore, we detected low levels of canine IL-31 in the thymus, testis, spleen, and kidneys, but not in the skin of atopic dogs.  相似文献   

Propagation of Asian isolates of canine distemper virus (CDV) in hamster cell lines     

Serageldeen Sultan  Nguyen Thi Lan  Toshiki Ueda  Ryoji Yamaguchi  Ken Maeda  Kazushige Kai 《Acta veterinaria Scandinavica》2009,51(1):38

Backgrounds

The aim of this study was to confirm the propagation of various canine distemper viruses (CDV) in hamster cell lines of HmLu and BHK, since only a little is known about the possibility of propagation of CDV in rodent cells irrespective of their epidemiological importance.

Methods

The growth of CDV in hamster cell lines was monitored by titration using Vero.dogSLAMtag (Vero-DST) cells that had been proven to be susceptible to almost all field isolates of CDV, with the preparations of cell-free and cell-associated virus from the cultures infected with recent Asian isolates of CDV (13 strains) and by observing the development of cytopathic effect (CPE) in infected cultures of hamster cell lines.

Results

Eleven of 13 strains grew in HmLu cells, and 12 of 13 strains grew in BHK cells with apparent CPE of cell fusion in the late stage of infection. Two strains and a strain of Asia 1 group could not grow in HmLu cells and BHK cells, respectively.

Conclusion

The present study demonstrates at the first time that hamster cell lines can propagate the majority of Asian field isolates of CDV. The usage of two hamster cell lines suggested to be useful to characterize the field isolates biologically.  相似文献   

Footpad reaction induced by Neospora caninum tachyzoite extract in infected BALB/c mice     

Omata Y  Kamiya H  Kano R  Kobayashi Y  Maeda R  Saito A 《Veterinary parasitology》2006,139(1-3):102-108

Little information is available regarding a delayed type hypersensitivity (DTH) reaction in neosporosis. In this study, we examined the elicitation of a DTH reaction in mice infected with Neospora caninum by inoculation of the footpad with tachyzoite antigens. The footpads of BALB/c mice infected with N. caninum and those of non-infected were injected with either the tachyzoite extract, or paraformaldehyde-fixed tachyzoites. In mice inoculated with N. caninum antigens on day 7 p.i. swelling peaked at 6h after injection of the tachyzoite extract. In mice inoculated on days 14, 28 and 56, swelling was observed between 6 and 72 h afterwards. Mice immunized with the tachyzoite extract plus adjuvant showed peak footpad swelling at 6h post injection, and the swelling had decreased at 24h or later. In contrast, mice injected before infection showed no specific swelling. In sections of footpads injected with the tachyzoite extract, exudate had accumulated at 6h post injection and clusters of infiltrated lymphocytes were observed at 48 h post injection. In mice administered anti-CD4+ cell monoclonal antibodies swelling had decreased at 24h post injection of the extract. These results indicate that mice infected with N. caninum produce a DTH reaction, which is a good indicator of the development of type 1 immune responses.  相似文献   

Relationships of culm surface area to other culm dimensions for bamboo, Phyllostachys pubescens     

Akio Inoue  Hideo Suga 《Journal of Forest Research》2009,14(4):236-239

We determine the relationships of culm surface area to other culm dimensions for one of the largest bamboo species, Phyllostachys pubescens Mazel ex Houzeau de Lehaie. A total number of 150 sample culms were collected from a stand of P. pubescens in Mt. Toshima, Kumamoto Prefecture, western Japan. The culm surface area for each sample was calculated, and then the relationships of the culm surface area to basal area and product of diameter at breast height (dbh) and culm height were analyzed. The relationship between culm surface area and basal area could be described successfully by the power equation, whereas there was a linear relationship of culm surface area to product of dbh and height. Although the regression equations determined here would be useful in estimating culm surface area of P. pubescens, it is necessary to select an appropriate equation depending on the purpose and available time and labor.  相似文献   

Antimicrobial activity against <Emphasis Type="Italic">Streptococcus sobrinus</Emphasis> and glucosyltransferase inhibitory activity of taxifolin and some flavanonol rhamnosides from kempas (<Emphasis Type="Italic">Koompassia malaccensis</Emphasis>) extracts     

Harlinda Kuspradini  Tohru Mitsunaga  Hideo Ohashi 《Journal of Wood Science》2009,55(4):308-313

Twenty plant materials collected from the islands of Java and Kalimantan in Indonesia were extracted with 50% aqueous ethanol (crude extract). The crude extracts were assayed for antimicrobial activities against Streptococcus sobrinus and for glucosyltransferase (GTase) inhibition. Fourteen extracts inhibited the growth of S. sobrinus by more than 50% and six extracts inhibited GTase activity by more than 50% at a concentration of 100 μg/ml. Koompassia malaccensis (kempas) extracts showed 90% depression of S. sobrinus growth and 80% inhibition of GTase activity at a concentration of 100 μg/ml. Kempas crude extracts were subjected to column chromatography using Sephadex LH-20 and then preparative high-performance liquid chromatography to isolate four compounds A, B, C, and D. These compounds were identified as taxifolin and the flavanonol rhamnoside isomers neoastilbin, astilbin, and isoastilbin, respectively, from ¹H and ¹³C nuclear magnetic resonance (NMR) spectra and other two-dimensional NMR techniques (COSY, HMBC, and HMQC). Each compound depressed the growth of S. sobrinus over a concentration range of 9.3242.7 μg/ml and showed GTase inhibitory activity with IC₅₀ values in the range 27.4–57.3 μg/ml. Taxifolin and flavanonol rhamnoside isomers isolated for the first time from kempas could be potent compounds for preventing dental caries. Part of this report was presented at the 57th Annual Meeting of the Japan Wood Research Society Conference, Hiroshima, 2007  相似文献   

First application of PCR-Luminex system for molecular diagnosis of fungicide resistance and species identification of fungal pathogens     

Hideo Ishii  Junko Tanoue  Michiyo Oshima  Wen-Hsin Chung  Kumiko Nishimura  Junichiro Yamaguchi  Fumihiro Nemoto  Kazuhiro So  Toshitaka Iwama  Hideaki Yoshimatsu  Motoshige Shimizu  Toru Kozawa 《Journal of General Plant Pathology》2008,74(6):409-416

Fungicide resistance in plant pathogens is often caused by a single point mutation in a gene encoding fungicide target proteins. Such is the case for resistance to MBI-D (inhibitors of scytalone dehydratase in melanin biosynthesis) fungicides in rice blast fungus (Magnaporthe oryzae), which is caused by a mutation in the scytalone dehydratase gene that results in a replacement of valine with methionine at codon 75 of the fungicide target protein. PCR-Luminex, a novel system developed for high-throughput analysis of single nucleotide polymorphisms (SNPs) was successfully introduced to diagnose MBI-D resistance using specific oligonucleotide probes coupled with fluorescent beads. The PCR-Luminex system was further tested for its potential in identifying species causing Fusarium head blight on wheat. Four major pathogens, Fusarium graminearum (=F. asiaticum), F. culmorum, F. avenaceum, and Microdochium nivale, known to cause the disease, were tested, and the species were identified using the PCR-Luminex method. So far, this report is the first on the application of the DNA-based PCR-Luminex system in the area of crop protection and/or agricultural sciences.  相似文献