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A 3-year-old-female, spayed Golden Retriever was examined for a unilateral retinal detachment with exophthalmos. Ultrasonographically, a mass was detected with intra- and extraocular extension. The orbit was exenterated and the dog recovered uneventfully. Histopathologic diagnosis was a primary choroidal melanoma with orbital extension, however, the behavioral and cytologic features were benign. Routine examinations postsurgically were nonremarkable. Twenty-one months after surgery the dog was euthanized for respiratory collapse with radiographic signs of metastasis. Necropsy revealed black lesions in the lung and liver. Histopathologic diagnosis was metastatic melanoma with morphology and behavior identical to the primary choroidal melanoma. This is the first definitive case of a canine choroidal melanoma with metastasis.  相似文献   
43.
The use of sentinel chickens in establishing the negative status of commercial poultry flocks depopulated due to exotic Newcastle disease (END) is considered to be an economically beneficial process. However, the costs and benefits of using sentinel chickens in noncommercial operations are in question. The objective of this study was to use sentinel chickens to evaluate whether adequate cleaning and disinfection coupled with an appropriate time period without susceptible poultry species on the premises would eliminate END virus from a noncommercial poultry operation and preclude the need for placement of sentinels in previously infected operations before declaring them free of virus. Noncommercial poultry operations were selected from the 2002 to 2003 END outbreak database. Operations included in the study had one or more isolations of END virus (ENDV) from cloacal or oropharyngeal swabs of birds on the premises. A total of 546 birds were placed on 53 premises. All sentinel birds sampled after placements were negative by virus detection methods and serologic tests. Results of this study indicate that time and the application of appropriate cleaning and disinfection procedures will adequately mitigate the risk of viable virus persisting in noncommercial poultry operations. In the future, this information may eliminate the need for sentinel bird placement to ensure virus free status of premises before repopulation, thereby decreasing the costs of END eradication.  相似文献   
44.
Companion planting of Cleome gynandra, of Kenyan origin, in beds of cut-flower roses reduces significantly red spider mite (Tetranychus urticae Koch) infestation without any detrimental effect on productivity or flower quality. The level of reduction is dependent upon the density of the C. gynandra plants with 15 plants in a 1.8 m2 bed (8.3 plants m2) being the most effective, planted either around the bed perimeter or within the rows of roses. The relatively high density of C. gynandra plants required may limit the direct application of this technology in export-focused, greenhouse rose production yet may be of significant value as a supplement to other mite-control strategies. The potential benefits of such companion planting for growers of field roses and those involved in some domestic markets are also evident. Research into the nature and extraction of the active, volatile mite-repellant components of C. gynandra is indicated.  相似文献   
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The continuing drive by the semiconductor industry to fabricate smaller structures using photolithography will soon require dimensional control at length scales comparable to the size of the polymeric molecules in the materials used to pattern them. The current technology, chemically amplified photoresists, uses a complex reaction-diffusion process to delineate patterned areas with high spatial resolution. However, nanometer-level control of this critical process is limited by the lack of direct measurements of the reaction front. We demonstrate the use of x-ray and neutron reflectometry as a general method to measure the spatial evolution of the reaction-diffusion process with nanometer resolution. Measuring compositional profiles, provided by deuterium-labeled reactant groups for neutron scattering contrast, we show that the reaction front within the material is broad rather than sharply defined and the compositional profile is altered during development. Measuring the density profile, we directly correlate the developed film structure with that of the reaction front.  相似文献   
47.
CASE DESCRIPTION: 2 dogs were evaluated because of vomiting and lethargy (a Toy Poodle; dog 1) and acute respiratory distress, vomiting, and anorexia (a Chihuahua; dog 2). Dog 1 had been exposed to a commercial hydrocarbon waterproofing spray 24 hours before the development of clinical signs, and dog 2 was examined 18 hours after exposure to a waterproofing spray containing heptane, a highly flammable liquid hydrocarbon. CLINICAL FINDINGS: In both dogs, major gastrointestinal tract abnormalities were ruled out but respiratory status worsened. Thoracic radiography revealed a diffuse interstitial pulmonary pattern, and hypoxemia was detected. TREATMENT AND OUTCOME: Hospitalization for monitoring and care was required for both dogs. The dogs recovered with supportive care, which included administration of oxygen, fluids, and bronchodilators. Additionally, dog 1 received glucocorticoids via inhalation and supplemental enteral nutrition, whereas dog 2 was treated with an antimicrobial. CLINICAL RELEVANCE: The dogs of this report developed hydrocarbon pneumonitis following exposure to waterproofing sprays. Such sprays contain potentially toxic hydrocarbons. The severity of the adverse effects associated with exposure may have been amplified because the dogs were physically small and were exposed to a relatively large amount of aerosolized spray within small areas. Development of chemical pneumonitis in pet animals is best prevented by application of waterproofing sprays in well-ventilated or outdoor areas from which pets have been excluded. With prolonged hospitalization and considerable monitoring and care, affected dogs can recover from these exposures.  相似文献   
48.
The growth, survival and reproductive performance of domesticated Australian stocks of the giant tiger shrimp Penaeus monodon were evaluated in trials conducted in 1997 and 2003. The 1997 trials assessed the performance of first generation progeny of wild broodstock from the northeast coast of Australia and fourth generation progeny of pond‐reared broodstock, which also originated from northeast coast wild stocks. In these trials, growth and survival of the shrimp were assessed when reared for 17 mo in tanks. Reproductive performance of the shrimp was assessed at 14.5 mo and 17 mo. The 2003 trials assessed the performance of first generation progeny of wild broodstock from the Gulf of Carpentaria (north coast of Australia). In these trials, growth and survival of shrimp were assessed when reared for 14 mo in tanks and raceways. Reproductive performance of the shrimp was assessed at 11 mo, 12 mo, and 15 mo. Growth and reproductive performance of the stocks varied between trials, families, ages and rearing systems. The most pronounced differences in growth and reproductive performance were between the 1997 and 2003 trials. At 11 mo of age, the average wet weight of the shrimp in the 2003 trials (females 117.1 ± 5.8 g; males 87.9 ± 7.6 g) was 200% greater than the average wet weight of shrimp in the 1997 trials (females 55.2 ± 6.8 g; males 41.2 ± 3.4 g). The reproductive performance of the shrimp was also higher in the 2003 trials in terms of the percentage of spawnings hatching (52.0% in 1997; 77.1% in 2003) and mean hatch rate (21.5% in 1997; 31.6% in 2003). Differences in the growth and reproductive performance of the tank‐reared stocks between years were indicative of significant improvements in the rearing environment, diet and husbandry techniques. Variation in the reproductive performance between families was consistent across rearing environments and at different ages and suggests the potential to improve reproductive performance through genetic selection. Notably, this study identified hatch rates of nauplii from the spawned eggs as a key area for future improvement of domesticated stocks reared in tanks and raceways. Future efforts to improve the growth and reproductive performance of domesticated P. monodon could benefit from integrating incremental improvements to husbandry with genetic selection.  相似文献   
49.
We demonstrate a method to evaluate the degree to which a meta-model approximates spatial disturbance processes represented by a more detailed model across a range of landscape conditions, using neutral landscapes and equivalence testing. We illustrate this approach by comparing burn patterns produced by a relatively simple fire spread algorithm with those generated by a more detailed fire behavior model from which the simpler algorithm was derived. Equivalence testing allows objective comparisons of the output of simple and complex models, to determine if the results are significantly similar. Neutral landscape models represent a range of landscape conditions that the model may encounter, allowing evaluation of the sensitivity and behavior of the model to different landscape compositions and configurations. We first tested the model for universal applicability, then narrowed the testing to assess the practical domain of applicability. As a whole, the calibrated simple model passed the test for significant equivalence using the 25% threshold. When applied to a range of landscape conditions different from the calibration scenarios, the model failed the tests for equivalence. Although our particular model failed the tests, the neutral landscape models were helpful in determining an appropriate domain of applicability and in assessing the model sensitivity to landscape changes. Equivalence testing provides an effective method for model comparison, and coupled with neutral landscapes, our approach provides an objective way to assess the domain of applicability of a spatial model.  相似文献   
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