Effects of Fish Size and Water Temperature on the Acute Toxicity of Copper for Japanese Flounder,Paralichthys olivaceus,and Red Sea Bream,Pagrus major     

Takeshi Furuta  Nakahiro Iwata  Kotaro Kikuchi 《Journal of the World Aquaculture Society》2008,39(6):766-773

The acute toxicities of copper were examined for Japanese flounder, Paralichthys olivaceus, and red sea bream, Pagrus major, in terms of fish size and water temperature. Artificial seawater of low pH of 5.4–6.7 was used as testing water to keep dissolved copper concentration at 0.04–41 mg Cu/L. Japanese flounder of 0.3–17 g and red sea bream of 0.5–13 g were exposed to different concentrations of copper for 96 h at 20 C under semistatic condition. Median‐lethal concentration for 96 h of Japanese flounder and red sea bream were 8.7–12.2 and 2.0–5.2 mg Cu/L, respectively. No significant relationships were observed between median‐lethal concentrations for 96 h and fish size for Japanese flounder, while the value decreased significantly with increasing fish size for red sea bream. Effect of water temperature on the acute toxicity was examined for Japanese flounder of 0.3 and 0.4 g at 10, 15, 20, and 25 C and red sea bream of 0.5 and 1.0 g at 12, 15, 20, and 25 C. Ninety‐six‐hour median‐lethal concentrations for Japanese flounder and red sea bream were 5.1–11.2 and 1.0–5.3 mg Cu/L, respectively. No significant relationships were observed between median‐lethal concentrations for 96 h and water temperature for both fish species.  相似文献   

The first survey of Theileria orientalis infection in Mongolian cattle     

Altangerel K  Battsetseg B  Battur B  Sivakumar T  Batmagnai E  Javkhlan G  Tuvshintulga B  Igarashi I  Matsumoto K  Inokuma H  Yokoyama N 《Veterinary parasitology》2011,182(2-4):343-348

In the present study, we have surveyed the presence of a bovine Theileria protozoan, Theileria orientalis, in Mongolian cattle and engorging tick populations from selected provinces and districts in Mongolia. The percentages of infection in the cattle and ticks ranged from 8.8 to 66.6 and from 3.7 to 73.3, respectively, on a per district basis. The genetic diversity of T. orientalis isolates was also studied, based on the protozoan gene encoding a major piroplasm surface protein (MPSP). At least five genotypes (types 1, 3, 5, 7, and N-3) of T. orientalis were found to be circulating among the Mongolian cattle and tick populations. In particular, types 3 and N-3 were common in most of the districts examined, while a strong geographical relationship among the genotypes was not detected in the present study. This is the first epidemiological report describing the presence of T. orientalis infection in Mongolian cattle.  相似文献   

Genotypic diversity of Theileria orientalis detected from cattle grazing in Kumamoto and Okinawa prefectures of Japan     

Yokoyama N  Ueno A  Mizuno D  Kuboki N  Khukhuu A  Igarashi I  Miyahara T  Shiraishi T  Kudo R  Oshiro M  Zakimi S  Sugimoto C  Matsumoto K  Inokuma H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(3):305-312

Theileria orientalis is a benign protozoan species that is widely distributed in Japan, yet sometimes causes serious economic losses in the livestock industry. In this study, we conducted a molecular survey based on genes encoding the major piroplasm surface protein (MPSP) and p23 for T. orientalis detected in cattle grazing in southern areas of Japan, consisting of 2 farms in Kumamoto prefecture (Aso and Kuma districts) and 3 farms in Okinawa prefecture (Ishigaki, Iriomote, and Yonaguni Islands). High prevalence rates of T. orientalis infection were shown in all the cattle populations using the diagnostic MPSP- and p23-PCR assays. Phylogenetic analyses revealed 4 MPSP genotypes and 3 p23 genotypes. Furthermore, MPSP genotype-specific PCR methods were developed in this study and wide distributions of 5-district genotypes of T. orientalis were observed for the examined farms. Our results indicate that at least 5 types of T. orientalis exist in Kumamoto and Okinawa prefectures of Japan and that genotype-specific PCR assays are highly applicable for the quarantine of transported cattle and for epidemiological surveys of bovine theileriosis in Japan.  相似文献   

Detection of the new Ehrlichia species closely related to Ehrlichia ewingii from Haemaphysalis longicornis in Yonaguni Island, Okinawa, Japan     

Matsumoto K  Takeuchi T  Yokoyama N  Katagiri Y  Ooshiro M  Zakimi S  Gaowa  Kawamori F  Ohashi N  Inokuma H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(11):1485-1488

We collected a total of 206 Haemaphysalis longicornis ticks by flagging in pastures in Yonaguni Island, Okinawa, Japan, in April 2008. Four of the 206 tick DNA samples tested were positive in a polymerase chain reaction (PCR) screening for the 16SrRNA gene of Anaplasmataceae. Partial sequences of 4 PCR products were identical to each other. Longer sequences of the 16SrRNA gene were successfully determined in 2 of the 4 tick samples, and the obtained 1,392 bp and 1,300 bp sequences revealed high similarity to the 16SrRNA gene sequences of the validated Ehrlichia species, including Ehrlichia ewingii, E. chaffeensis, and E. canis (98.3-98.6%). We also sequenced 1,304 bp of the groEL gene from the 2 tick samples, and found that these had the highest similarity to sequences of E. ewingii (94.0-94.4%) in the validated ehrlichial species. Based on the 16SrRNA and groEL gene sequences, the ehrlichial agents detected in this study were similar to the Ehrlichia species detected in Asia and may compose a new Ehrlichia species with other Ehrlichia species detected in Asia.  相似文献   

Estimation of genetic parameters of defective appearances in Japanese Black heifer calves in Kagoshima     

Hidemi Oyama  Kiyoto Imamura  Shinichi Sakamoto  Kazutaka Nishi  Kotaro Kawabe  Shin Okamoto  Takeshi Honda  Kenji Oyama  Takeshi Shimogiri 《Animal Science Journal》2020,91(1)

Defective appearances, including white spotting (WS), tongue defect (TD), and nipple defect (ND), in Japanese Black cattle potentially lead to economic losses to farmers in Japan. We estimated genetic parameters of defective appearances using 553,433 records of Japanese Black heifer calves housed in the Kagoshima Prefecture. Variance and covariance were estimated using the Gibbs sampling algorithm. The estimated heritability ranged from 0.29 for TD to 0.76 for WS. Percent breeding value (%BV) estimates indicated high variation in WS and ND among sires, reflecting higher heritability. Furthermore, there was a positive linear relationship between the %BV estimate of a sire and the mean incidence rate of each defect in his female offsprings. TD was positively associated with other defects. Therefore, genetic factors strongly affect the incidence of defective appearances in Japanese Black cattle.  相似文献   

Investigation of OECD 301F ready biodegradability test to evaluate chemical fate in a realistic environment     

Saki Takekoshi  Kotaro Takano  Yoshihide Matoba  Masayuki Sato  Akira Tachibana 《Journal of Pesticide Science》2021,46(2):143

The OECD 301F ready biodegradability test has been approved for use under the Japanese Chemical Substances Control Law since 2018. This test uses activated sludge obtained from a sewage treatment plant instead of the standard activated sludge used for the 301C test. In addition, the test is allowed to add an inert support or emulsifying agent, and/or to change the volume of the test medium. In this study, we first confirmed that the standard sludge had lower biodegradation activities than the sludge taken from a sewage treatment plant. Second, we showed that biodegradation percentages were increased by adding suitable amounts of silica gel or Tween 80. Third, we found that the biodegradations were accelerated by only increasing the medium volume under the conditions that concentrations of chemical, silica gel, and sludge were held constant. These findings are expected to contribute to the appropriate evaluation of chemical fate in a realistic environment.  相似文献   

Emission index for evaluation of volatile organic compounds emitted from tomato plants in greenhouses     

Kotaro Takayama  Roel M.C. Jansen  Eldert J. van Henten  Francel W.A. Verstappen  Harro J. Bouwmeester  Hiroshige Nishina 《Biosystems Engineering》2012,113(2):220-228

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Prevalence and mechanism of antimicrobial resistance in Staphylococcus aureus isolates from diseased cattle, swine and chickens in Japan     

Baba K  Ishihara K  Ozawa M  Usui M  Hiki M  Tamura Y  Asai T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(5):561-565

Antimicrobial administration is essential for the control and treatment of diseases in animals, but the emergence and prevalence of antimicrobial-resistant Staphylococcus aureus is a significant concern during animal production. Here we investigated the antimicrobial susceptibility of S. aureus from diseased food-producing animals and molecularly characterized the methicillin-resistant and fluoroquinolone-resistant isolates. A total of 290 S. aureus isolates obtained from cattle (n=246), swine (n=16), and chickens (n=28) between 2003 and 2009 were examined for antimicrobial susceptibility against 9 antimicrobials using an agar dilution method. Resistance to penicillin (PC) was most frequently found (24.8%), followed by oxytetracycline (OTC, 10.0%), dihydrostreptomycin (4.1%), erythromycin (EM, 3.1%), enrofloxacin (ERFX, 2.1%), and kanamycin (1.7%). The PC resistance rate was significantly higher in swine than in cattle (P<0.01) and chickens (P<0.01). The resistance rates to OTC, EM and ERFX were significantly higher in swine and chickens than in cattle (P<0.05). Methicillin-resistant S. aureus (MRSA) was recovered from milk derived from a cow with mastitis in 2003; sequence type 8, SCCmec type IV and spa type t024. In the six ERFX-resistant strains isolated after 2003, amino acid substitutions in ParC with/without GyrA were detected. As the prevalence of MRSA and FQ-resistant S. aureus in the animals should be noticed, continuous monitoring is necessary to control resistance to clinically important antimicrobials in S. aureus from food-producing animals.  相似文献   

Effect of seasonal changes on the carbohydrate levels of eelgrass Zostera marina at Odawa Bay     

Kotaro Kikuchi  Yasuo Kawasaki  Shusei Sato 《Fisheries Science》2001,67(4):755-757

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Prevalence and Molecular Analyses of Hemotrophic Mycoplasma spp. (Hemoplasmas) Detected in Sika Deer (Cervus nippon yesoensis) in Japan     

Michihito TAGAWA  Kotaro MATSUMOTO  Naoaki YOKOYAMA  Hisashi INOKUMA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(3):401-407

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