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11.
Studies were carried out to determine the cause of death in a prematurely born Thoroughbred foal that died 24 hours after birth. Necropsy revealed gross lesions suggestive of septicemia. A commercial Leptospira polymerase chain reaction (PCR) assay designed to specifically amplify the hemolysis-associated protein 1 (hap1) gene present only in pathogenic Leptospira strains detected the presence of Leptospira DNA in various tissues of the foal. Histologic examination of lung, liver, kidney, and myocardium revealed numerous spirochetes in Warthin-Starry-stained tissue sections. Results of PCR analysis and histologic examination suggested a leptospiral infection in the newborn foal. At the moment of death, the infection coexisted with a streptococcal-associated aspiration bronchopneumonia and postpartum septicemia. These findings indicate that the PCR assay based on the amplification of the hap1 gene represents a useful tool for specific detection of pathogenic leptospira in field samples taken from horses.  相似文献   
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As clinical toxoplasmosis is not considered a problem in pigs, the main reason to implement a control strategy against Toxoplasma gondii (T. gondii) in this species is to reduce the establishment of T. gondii tissue cysts in pork, consequently reducing the risk of the parasite entering the human food chain. Consumption of T. gondii tissue cysts from raw or undercooked meat is one of the main sources of human infection, with infected pork being considered a high risk. This study incorporates a mouse bioassay with molecular detection of T. gondii DNA to study the effectiveness of vaccination (incomplete S48 strain) in its ability to reduce tissue cyst burden in pigs, following oocyst (M4 strain) challenge. Results from the mouse bioassay show that 100% of mice which had received porcine tissues from vaccinated and challenged pigs survived compared with 51.1% of mice which received tissues from non-vaccinated and challenged pigs. The presence (or absence) of T. gondii DNA from individual mouse brains also confirmed these results. This indicates a reduction in viable T. gondii tissue cysts within tissues from pigs which have been previously vaccinated with the S48 strain. In addition, the study demonstrated that the main predilection sites for the parasite were found to be brain and highly vascular muscles (such as tongue, diaphragm, heart and masseter) of pigs, while meat cuts used as human food such as chop, loin, left tricep and left semitendinosus, had a lower burden of T. gondii tissue cysts. These promising results highlight the potential of S48 strain tachyzoites for reducing the number of T. gondii tissues cysts in pork and thus improving food safety.  相似文献   
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Species of the family Clionaidae (Porifera: Demospongiae) that excavate shell of the silver‐lip pearl oyster, Pinctada maxima, in north Western and Northern Australia are described. Two species belong to the genus Cliona and one species to the closely related genus Pione. Cliona orientalis has only recently been reported from Australia in living and dead coral on the Great Barrier Reef, and this is the first report of this species from north Western and Northern Australia. Cliona dissimilis is reported from Australia for the first time. Pione velans was first described from Shark Bay, Western Australia and this study extends its distribution from Albany, south Western Australia to Port Bremer in the Northern Territory. The most common species found was C. dissimilis. Pione velans and C. orientalis were also present, although the latter species was rare. Cliona dissimilis and P. velans were found to be sexually reproductive in some shells with specimens of C. dissimilis with oocytes in May and P. velans in September 1999. Egg development was synchronous, indicating that the sponges were oviparous and would broadcast gametes in a spawning event.  相似文献   
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Abstract– Ageing and calculation of growth rate of eels has always been controversial, and remarkably little validation has been reported. This article describes the growth of yellow eels from three lakes in the Burrishoole system, Ireland, as determined by back-calculation from otoliths prepared by burning and cracking. Eels captured by fyke net ranged in length from 25.0 cm to 98.5 cm and the ages ranged from 6 to 49 years. Back-calculated growth was slow, with mean annual increments of 2.08 cm, 1.40 cm and 1.97 cm for the three lakes. Yellow eels captured in the Burrishoole system in 1987 and 1988 were marked by Pan Jet inoculated alcian blue dye and released back into the three lakes. Recaptures made over the following three years yielded considerable growth data. Mean annual growth rates recorded were 2.30 cm, 1.07 cm and 0.97 cm. These data compare favorably with the calculated growth rates, thereby validating the otolith analysis for the eels in the Burrishoole system.  相似文献   
16.
We describe a giant titanosaurid sauropod dinosaur discovered in coastal deposits in the Upper Cretaceous Bahariya Formation of Egypt, a unit that has produced three Tyrannosaurus-sized theropods and numerous other vertebrate taxa. Paralititan stromeri is the first tetrapod reported from Bahariya since 1935. Its 1.69-meter-long humerus is longer than that of any known Cretaceous sauropod. The autochthonous scavenged skeleton was preserved in mangrove deposits, raising the possibility that titanosaurids and their predators habitually entered such environments.  相似文献   
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