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A positive relationship exists between the number of times a subject responds with a psychogalvanic response to an orienting or alerting stimulus (tone) and the rate of learning in classical conditioning. This is seen by a correlation (p=.65 and .643 when corrected for ties) between the number of orienting responses and the resistance to extinction of the conditioned psychogalvanic response.  相似文献   
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Abstract. Microcystis aeruginosa is a common cyanobacterium of nutrient-rich fresh waters. It has been implicated in a large number of poisoning incidents involving wild and domesticated terrestrial animals. The study showed that a pure strain of M. aeruginosa toxic to mice was non-toxic to rainbow trout immersed in a culture for 10 days. In contrast, when presented by intraperitoneal injections Microcystis caused an acute toxic response with 100% mortality of fish within 36 h. The histopathology of the response is described and contrasted with that to another cyanobacterium, Anabaena cylindrica , which was shown to be non-toxic by immersion or injection.  相似文献   
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Magnetic resonance (MR) cholangiopancreatography is useful in humans to diagnose biliary and pancreatic diseases. Some of these protocols incorporate the use of secretin, which stimulates the exocrine pancreas to release bicarbonate with secondary dilation of the pancreatic duct. We compared the utility and quality of multiple hepatic‐pancreaticobiliary MR imaging sequences before and after secretin stimulation of the pancreatic duct in five healthy cats. Multiple MR sequences were evaluated, including fast Spoiled Gradient Recalled in‐ and out‐of‐phase, Single Shot Fast Spin Echo (SSFSE), T2 Fast Spin Echo, MR cholangiopancreatography (pre‐ and postsecretin administration), and Fast Acquisition with Multiphase Efgre (FAME) (postsecretin and before and after gadolinium administration). The MR cholangiopancreatography protocol with secretin stimulation was feasible and yielded high‐contrast maps of the biliary ductal anatomy but the pancreactic duct was seen inconsistently. The FAME series most consistently provided visualization of biliary and postsecretin pancreatic ductal anatomy, combined with very good depiction of the liver and pancreas. The remaining sequences each had satisfactory utility and diagnostic quality, with the exception of the SSFSE sequences. Secretin improved the conspicuity of the pancreatic duct.  相似文献   
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SUMMARY: Boophilus microplus ticks collected from calves with patent Anaplasma marginale infections were incubated at either 4 to 5°C, 14°C, 22°C, 27°C or 37°C for up to 14 days. Extracts prepared either from larvae, nymphs, immature females, adult males or mixtures of both sexes were infective for 14 of the 16 splenectomised calves inoculated. Extracts either from nymphs or from adult ticks deriving from nymphs moulted in vitro were infective for 11 of 12 nonsplenectomised calves. Possible application of the findings to producing a vaccine strain of A. marginale is discussed.  相似文献   
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Transarticular external skeletal (TES) fixators were applied unilaterally to the stifle joints of 10 young adult dogs. After 4 weeks, the fixators were removed from all dogs. Two dogs were not allowed a remobilization period, whereas 8 dogs were provided with 4 additional weeks of weight-bearing activity in a kennel run. Four dogs were given high-molecular weight hyaluronic acid by intra-articular injection weekly during the remobilization period. Clinical gait evaluations and range of motion were determined during the remobilization period. Articular cartilage samples from both stifle joints of all dogs were evaluated histologically and histochemically. No significant differences in gait scores or range of motion were noted between treated and untreated dogs. Articular cartilage proteoglycan content was reduced after 4 weeks of trans-stifle external skeletal fixation as determined by loss of alcian blue (AB) histochemical staining. Improved homogeneity of histochemical staining was observed after remobilization. However, remobilization was associated with histological damage to the surface and tangential layers of articular cartilage. Remobilization combined with hyaluronic acid (HA) therapy improved histochemical staining and reduced structural damage to articular cartilage when compared with remobilization alone.  相似文献   
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