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11.
Canine distemper virus.   总被引:5,自引:0,他引:5  
Vaccine-based prophylaxis has greatly helped to keep distemper disease under control. Notwithstanding, the incidence of canine distemper virus (CDV)-related disease in canine populations throughout the world seems to have increased in the past decades, and several episodes of CDV disease in vaccinated animals have been reported, with nation-wide proportions in some cases. Increasing surveillance should be pivotal to identify new CDV variants and to understand the dynamics of CDV epidemiology. In addition, it is important to evaluate whether the efficacy of the vaccine against these new strains may somehow be affected.  相似文献   
12.
Contrast-enhanced ultrasound was used to study focal and multifocal lesions of the spleen in 26 dogs and two cats affected by 11 benign and 18 malignant splenic diseases. A second-generation microbubble contrast medium (Sonovue) was injected into the cephalic vein and enhancement patterns were subjectively described and time intensity curves calculated. Final diagnosis was obtained by histopathologic examination after splenectomy (n=19) or by needle aspiration and sonographic follow-up after 4 and 8 weeks (n=9). Contrast-enhanced ultrasound parameters, improving the characterization between benign and malignant lesions, were established. The most useful criterion was the hypoechogenicity of the lesion in the wash-out phase combined with the presence of tortuous feeding vessels, which was observed in association with malignancy. All malignant lesions were hypoechoic to the surrounding spleen 30s after starting the contrast medium injection. Lymphosarcoma and hemangiosarcoma had characteristic perfusion patterns. Lymphosarcoma had rapid time to peak and early wash-out phase with a honeycomb pattern during the wash-out. Hemangiosarcomas were large nonperfused masses in all phases surrounded by hypervascular splenic parenchyma. Benign lesions except one hematoma and a benign histiocytoma had the same perfusion pattern as the surrounding spleen. Ultrasonographic and contrast-enhanced ultrasound findings of an accessory spleen are reported. Contrast-enhanced ultrasound can improve the characterization of focal or multifocal lesions of the spleen.  相似文献   
13.
CDV is a highly contagious viral pathogen causing a lethal systemic disease in dogs and other carnivores. Several lineages or genotypes of CDV exist that are variously distributed throughout several continents. Legal or uncontrolled trading of animals may modify the epidemiology of CDV, introducing novel strains in CDV-na?ve areas or accounting for the resurgence of CDV in areas where vaccine prophylaxis was effective and successful to control the disease. A hemi-nested PCR system was developed to genotype strains of the major CDV lineages, America-1, Europe, Asia-1, Asia-2 and Arctic. The assay was tested using a collection of 27 laboratory and vaccine strains and of 36 field CDV strains. Distinct lineages could be differentiated by specific primers targeted to the H gene. The method could be useful for molecular epidemiological studies of CDV, providing a tool for large-scale studies, and for the diagnosis of vaccine-related disease.  相似文献   
14.
15.

Purpose

The USLE-MM estimates event normalized plot soil loss, Ae,N, by an erosivity term given by the runoff coefficient, QR, times the single-storm erosion index, EI30, raised to an exponent b1?>?1. This modeling scheme is based on an expected power relationship, with an exponent greater than one, between event sediment concentration, Ce, and the EI30/Pe (Pe = rainfall depth) term. In this investigation, carried out at the three experimental sites of Bagnara, Masse, and Sparacia, in Italy; the soundness of the USLE-MM scheme was tested.

Materials and methods

A total of 1192 (Ae,N, QREI30) data pairs were used to parameterize the model both locally and considering all sites simultaneously. The performances of the fitted models were established by considering all erosive events and also by distinguishing between events of different severity.

Results and discussion

The b1 exponent varied widely among the three sites (1.05–1.44) but using a common exponent (1.18) for these sites was possible. The Ae,N prediction accuracy increased in the passage from the smallest erosion events (Ae,N?≤?1 Mg ha?1, median error =?3.35) to the largest ones (Ae,N?>?10 Mg ha?1, median error =?1.72). The QREI30 term was found to be usable to predict both Ae,N and the expected maximum uncertainty of this prediction. Soil erodibility was found to be mainly controlled by the largest erosion events.

Conclusions

Development of a single USLE-MM model appears possible. Sampling other sites is advisable to develop a single USLE-MM model for a general use.
  相似文献   
16.
Marisma, one of the largest salt-marsh alluvial areas in SW Spain, has been reclaimed since 1970 by artificial drainage and amendment with phosphogypsum (PG) so as to reduce Na+ saturation. Within the reclaimed area, two 250- × 20-m plots were treated as follows: (1) amendment with 25 Mg/ha of PG every 2 to 3 years between 1979 and 2003 (plot PY); (2) like PY but PG treatment stopped after 1997 (plot DR). A contiguous virgin Marisma salt-marsh plot (MV), neither drained nor amended, was the control. In MV, soil microbial biomass C, most enzyme activities and total organic C content were much greater than in PY and DR soils, despite the salinity stress. The decrease in soil organic matter content in PY and DR soils was likely due to cotton-cropping practices, which favoured the organic C mineralisation and nutrients removal by crops. Microbial activity of MV soil, probably stimulated by the rhizodepositions of the natural vegetation, did not suffer from the osmotic effect due to the raising of soil solution ionic strength. Microbial quotient could be ranked as MV > PY > DR, whereas the metabolic quotient had an opposite trend. Thus, both quotients suggested that the interruption of PG amendment was not favouring microbial activity. Principal component analysis clearly identified the chemical and biochemical soil properties mostly affected by the reclamation and also indicated the longer PG amendment in PY plot. Stepwise discriminant analysis identified two physiologically different types of soil microflora, one less active present in the MV virgin soil and another more active present in the reclaimed PY and DR soils.  相似文献   
17.
Animal growth does not follow a linear pattern, being explained mathematically by functions that have parameters with biological meaning. These parameters are used to estimate the expected weight of animals at specific ages. Several nonlinear models have been used to describe growth. This study was carried out to estimate the parameters of logistic, Gompertz, Richards and von Bertalanffy growth curve models in a sample of Podolica young bulls to determine the goodness of fit. Animals were weighed every 3 months from birth to 810 days of age. The results indicate that all the growth models used were easily fitted to the observed data with Gompertz and logistic functions presenting less computational difficulty in terms of number of iterations to achieve convergence. Moreover, logistic and Richards equations provided the best overall fit being useful to describe the growth of Podolica bulls. Considering that the literature lacks information on growth curves in Podolica breed, the study of a mathematical model for growth describing the developmental pattern of a specific population within a peculiar environment is a useful tool to improve Podolica breed production.  相似文献   
18.
Enrofloxacin (E) is commonly used in veterinary medicine. It is necessary to perform pharmacokinetic/dynamic studies to minimize the selection of resistant mutants of bacteria and extend the efficacy of antimicrobial agents. Eight healthy adult Pogona vitticeps were assigned into two groups of equal size and treated with a single intramuscular injection of E at 10 mg/kg. Blood samples were withdrawn at different scheduled times for each group, and rectal swabs were collected. E and ciprofloxacin (active metabolite) blood concentrations were quantified by an HPLC validated method, while the in vitro antimicrobial susceptibility was evaluated by the Kirby–Bauer disc diffusion susceptibility test. The pharmacokinetic profiles of E gave similar pharmacokinetic parameters irrespective of the collection time schedule. Bacteria isolation showed the presence of both E. coli, Salmonella enterica subspecies enterica and subspecies 3a, Proteus spp., and Pseudomonas spp. The majority of isolated colonies were sensitive to E, but the treatment did not reduce the number of bacteria in faeces. Results suggest that E is able to reach blood concentrations high enough to kill susceptible bacteria (MIC < 0.9 μg/mL), but at the same time does not significantly affect intestinal bacteria.  相似文献   
19.
Environmental stress as salinity can negatively affect the physiology of tomato plants. Conditions leading to a reduction of transpiration can contribute to greater tolerance to salinity. Use of kaolin-based particle film technology (PFT) may be an effective tool to control stomatal conductance and transpiration rate, thus mitigating the detrimental effect of salinity. The present three-year study has investigated the effects of kaolin application on leaf gas exchange, leaf water potential, leaf and canopy temperature of field-grown tomato, irrigated with brackish water by drip method, in southern Italy. Treatments were: (1) three salinity levels of irrigation water (electrical conductivity of water = 0.5, 5 and 10 dS m?1); (2) tomato plants treated or not with kaolin; and (3) two cultivars in each year. The increase in salinity caused the reduction of leaf water potential, stomatal conductance, net photosynthesis and transpiration rate, and the increase of leaf and canopy temperature. Kaolin has resulted in an improvement of leaf water potential, and the reduction in gas exchange variables in low-salinity conditions. Under high salinity, kaolin was effective in limiting the reductions in net photosynthesis and reducing leaf and canopy temperature. These latter variables were slightly affected by kaolin, in different ways in respect to the saline treatments; while in non-saline conditions were 0.2–0.5°C higher in the kaolin-treated plants, the situation was reversed in more saline treatment. The variation of leaf and canopy temperature shows that kaolin influences the thermal balance mainly for the dual effect of reflection of the incident radiation and partial occlusion of the stomata. Kaolin mitigated detrimental effects of salinity also on yield, contributing to the improvement of income for the farmers. The use of kaolin-based PFT may be an effective tool to alleviate salinity stress in tomato production under arid and semi-arid conditions.  相似文献   
20.
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