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1.
Toxoplasma gondii is a zoonotic protozoan pathogen that infects many endothermic vertebrates, including humans; the domestic cat and other felids serve as the definitive host. Macropodids are considered highly susceptible to toxoplasmosis. Here, we describe the clinical, pathologic, and immunohistochemical findings of an outbreak of systemic toxoplasmosis in a mob of 11 red kangaroos (Macropus rufus), with high morbidity (73%) and mortality (100%) rates. Affected animals had either severe and rapidly deteriorating clinical conditions or sudden death, which was correlated with widespread necrotizing lesions in multiple organs and intralesional T. gondii organisms identified via MIC3-specific immunohistochemistry and confirmed by REP529-specific rtPCR. Quantification of parasites demonstrated the highest parasite density in pulmonary parenchyma compared with other tissues. Our study highlights the continued importance of this severe condition in Australian marsupials.  相似文献   
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The DNDC (DeNitrification-DeComposition)-Rice model, one of the most advanced process-based models for the estimation of greenhouse gas emissions from paddy fields, has been discussed mostly in terms of the reproducibility of observed methane (CH4) emissions from Japanese rice paddies, but the model has not yet been validated for tropical rice paddies under alternate wetting and drying (AWD) irrigation management, a water-saving technique. We validated the model by using CH4 and nitrous oxide (N2O) flux data from rice in pots cultivated under AWD irrigation management in a screen-house at the International Rice Research Institute (Los Baños, the Philippines). After minor modification and adjustment of the model to the experimental irrigation conditions, we calculated grain yield and straw production. The observed mean daily CH4 fluxes from the continuous flooding (CF) and AWD pots were 4.49 and 1.22?kg?C?ha?1?day?1, respectively, and the observed mean daily N2O fluxes from the pots were 0.105 and 34.1?g?N?ha?1?day?1, respectively. The root-mean-square errors, indicators of simulation error, of daily CH4 fluxes from CF and AWD pots were calculated as 1.76 and 1.86?kg?C?ha?1?day?1, respectively, and those of daily N2O fluxes were 2.23 and 124?g?N?ha?1?day?1, respectively. The simulated gross CH4 emissions for CF and AWD from the puddling stage (2 days before transplanting) to harvest (97 days after transplanting) were 417 and 126?kg?C?ha?1, respectively; these values were 9.8% lower and 0.76% higher, respectively, than the observed values. The simulated gross N2O emissions during the same period were 0.0279 and 1.45?kg?N?ha?1 for CF and AWD, respectively; these values were respectively 87% and 29% lower than the observed values. The observed total global warming potential (GWP) of AWD resulting from the CH4 and N2O emissions was approximately one-third of that in the CF treatment. The simulated GWPs of both CF and AWD were close to the observed values despite the discrepancy in N2O emissions, because N2O emissions contributed much less than CH4 emissions to the total GWP. These results suggest that the DNDC-Rice model can be used to estimate CH4 emission and total GWP from tropical paddy fields under both CF and AWD conditions.  相似文献   
3.
Three bovine amphistomes, Calicophoron calicophorum, Orthocoelium streptocoelium and Homalogaster paloniae, are common in Japan. This study was carried out to describe ITS2 sequences in the 3 species, and to evaluate a PCR-RFLP technique based on ITS2 sequence for the species identification in single eggs of the parasites. The ITS2 sequences of the three species contained 19 variable sites including one gap. The sequence difference between species was 4.2-5.3%. The three species of amphistomes were identified based on the difference in the restriction sites of Acc II on the ITS2 sequence.  相似文献   
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The duality of teleost gonadotropins   总被引:5,自引:0,他引:5  
The duality of salmon gonadotropins has been proved by biochemical, biological, and immunological characterization of two chemically distinc gonadotropins. GTH I and GTH II were equipotent in stimulating estradiol production, whereas GTH II appears to be more potent in stimulating maturational steroid synthesis. The ratio of plasma levels and pituitary contents of GTHs and the secretory control by a GnRH suggest that GTH I is the predominant GTH during vitellogenesis and early stages of spermatogenesis in salmonids, whereas GTH II is predominant at the time of spermiation and ovulation. GTH I and GTH II are found in distinctly separate cells. In trout, GTH I is expressed first in ontogeny, whereas GTH II cells appear coincident with the onset of spermatogenesis and vitellogenesis, and increase dramatically at the time of final reproductive maturation. Comparison of the amino acid sequences of polypeptides and the base sequences of cDNA revealed that salmon GTH I β is more similar to bovine FSHβ than bovine LHβ and salmon GTH II β shows higher homology to bovine LHβ than to bovine FSHβ. The existence of two pituitary gonadotropins in teleosts as well as tetrapods suggests that the divergence of the GTH gene took place earlier than the time of divergence of teleosts from the main line of evolution leading to tetrapods.  相似文献   
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Aerosol and precipitation samples were obtained at the summit of Mt. Fuji, the highest peak (3776m a.s.l.) in Japan, in the summers of 1997, 1998, and 1999. The mountaintop might be affected by valley wind during the afternoon, but is located in the free troposphere during the morning. The temporal variations of chemical species in the aerosol and precipitation samples correspond with meteorological conditions. The SO4 2? in the aerosol and precipitation exhibits high concentration with low temperature air mass, indicating the influence of long range transport from the Asian Continent. The contribution of the free troposphere to the chemical species obtained at the summit is estimated to be at least 30% during the summer season.  相似文献   
9.
Ciguatoxin: isolation and chemical nature   总被引:5,自引:0,他引:5  
Ciguatoxin, the agent responsible for ciguatera, a disease produced in humans from ingestion of certain fishes, has been isolated from specimens of the moray eel, Gymnothorax javanicus. The toxin is apparently a lipid containing quaternary nitrogen, hydroxyl, and carbonyl functions.  相似文献   
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