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961.
962.
963.
Pyloric and oesophageal dysfunction in the cat   总被引:3,自引:0,他引:3  
The paper describes the symptoms, diagnosis and treatment of pyloric stenosis in thirteen cats, associated in some animals, with megalo-oesophagus.  相似文献   
964.
The objective of this research was to culture the calanoid copepod Pseudodiaptomus euryhalinus, Johnson 1939, and the harpacticoid Tisbe monozota, Bowman, 1962, in monospecific and combined cultures (P. euryhalinus : T. monozota at 1:1, 2:1, and 1:2 starting ratios), and to compare the nauplii, copepodite, and adult production. Mean total production ranged from 740.3 ± 137.5 organisms/L (P. euryhalinus) to 884.3 ± 489.7 organisms/L (T. monozota) for monospecific cultures. The 1:1 ratio mixed cultures gave 780.4 ± 155.8 organisms/L, those with the 2:1 and 1:2 P. euryhalinus and T. monozota starting ratios produced 710.1 ± 195.2 and 799.7 ± 232.5 organisms/L, respectively, and there were no significant difference among treatments. All mixed cultures gave significantly lower copepodite productions than the monocultures of each species. In addition, the tendency to a decreased progeny production of the initial females of T. monozota indicates that the outcome of long‐term mixed cultures would production either a high dominance of P. euryhalinus, or monocultures of this species .  相似文献   
965.
Correct knowledge of disturbance ecology is essential for understanding the characteristic behavior of forest ecosystems and for guiding appropriate management strategies. However, the role of natural disturbances in shaping European mountain forest ecosystems has not been adequately studied, possibly because of the perception that the development of most European forests is primarily shaped by human influences and/or fine-scale gap-phase dynamics.In the present study, we investigate the long-term disturbance history of old protected forest dominated by Norway spruce in the Parangalitsa Reserve, Bulgaria. We used aerial photo interpretation and dendroecological methods to reconstruct the history of wind, insect, and fire disturbances across a topographically complex landscape. Over the past 150 years wind has been the most important disturbance agent in this ecosystem and at least 18% of the forested area shows evidence of high-severity blowdowns. Windthrow patches ranged in size from <1 ha to >10 ha (minimum 0.11 ha, mean 0.16 ha, maximum 10 ha). Although small disturbances were much more frequent, few larger blowdowns accounted for most of the disturbed area. Pure coniferous and single-cohort coniferous forest patches were more affected by blowdowns than mixed coniferous-deciduous and multi-cohort coniferous forest patches. Although bark beetle (Ips typhographus) populations were large enough to cause mortality of some live trees, the populations did not grow to epidemic proportions during recent decades. Fire disturbance was of limited importance in the last 200 years and only two patches (4% of the study area) showed evidence of fire.The present research indicates that wind disturbances have been characteristic of these ecosystems at least over the past decades to centuries. Thus, blowdowns appear integral to the normal function and structure of the Picea-dominated mountain forests in the region and such events, in and of themselves, do not represent unhealthy forest conditions or environmental emergencies. Management strategies that aim to maintain these ecosystems within a natural range of variation should incorporate wind disturbances into the management strategy. The frequency and magnitude of future wind disturbances may be considered within the historical framework described in the current study to assess potential effects of climate change on altered disturbance regimes.  相似文献   
966.
REASONS FOR PERFORMING STUDY: Proton pump inhibitors (PPIs) are a mainstay of treatment for acid-related ulceration in man and horses. Currently, only an oral preparation of omeprazole is approved for use in horses in the USA. Intravenous administration of a PPI would provide a useful therapeutic alternative for those foals in which oral medication is not feasible. OBJECTIVE: To investigate the pharmacokinetics and pharmacodynamics of pantoprazole following i.v. or intragastric administration in healthy neonatal foals. METHODS: Seven healthy foals age 6-12 days at the start of the study were evaluated. Treatments included no drug administration, i.v. pantoprazole (1.5 mg/kg bwt) and intragastric pantoprazole (1.5 mg/kg bwt). Intragastric pH was recorded for 24 h after drug administration for pharmacodynamic evaluation. Plasma pantoprazole concentrations were measured using high-performance liquid chromatography. RESULTS: Plasma concentrations of pantoprazole were detectable at the 5 min sampling point following i.v. or intragastric administration. Bioavailability of intragastric-administered pantoprazole was 41%. Baseline mean hourly pH was 1.5-6.1. There was a statistically significant increase in mean hourly pH relative to untreated foals 2-24 h after i.v. or intragastric pantoprazole administration. CONCLUSIONS: Based on these data, i.v. or intragastric administration of pantoprazole results in a significant, prolonged increase in intragastric pH. POTENTIAL RELEVANCE: The i.v. formulation of pantoprazole may provide a clinically useful alternative means of acid suppression in foals unable to tolerate enteral administration of a PPI, such as those with pyloric outflow obstruction.  相似文献   
967.
An investigation of the carbon economy of single S184 white clover plants nodulated with an effective strain of Rhizobium trifolii growing on N-free nutrient solution and supplied with 150 parts/106 N as NH4NO3 has shown that 10% more of the C fixed per day is available for growth in the plants supplied with combined N. The difference between the two groups of plants is a result of higher respiratory activity in the roots of plants growing exclusively on N2. In terms of shoot growth, however, the difference in growth rate is likely to be less than 10%, because the rate of root growth is greater in the plants supplied with a moderate level of combined N. There is no evidence that NO-3 and CO2 compete for photosynthetically produced reductant in the leaves of plants grown on N2+NH4NO3, since no reduction in net photosynthesis was observed in plants assimilating combined N. An experiment carried out on detached leaflets of white clover grown on N2 and on N2+ NH4NO3 has shown that NO-3 -reducing activity is present in the leaflets of plants grown on N2+ NH4NO3 but not in plants grown on N2 and that the activity is light-dependent. Measurements of 14CO2 respired in the light and dark by leaflets previously allowed to photosynthesize 14CO2 showed that the ratio of 14CO2 output in the light to 14CO2 output in the dark was no higher in plants grown on N2+ NH4NO3 than in plants grown on N2. This observation is consistent with the finding that N source does not affect net photosynthesis in whole plants.  相似文献   
968.
969.
970.
The prevalence of chronic valvular disease was studied in 494 cavalier King Charles spaniels with a mean (+/- sd) age of 3.0 +/- 2.7 years. Cardiac murmurs were detected in 65 (13.2 per cent) of the dogs. Among 61 cavalier King Charles spaniels with a mean age of 6.4 +/- 2.8 years, cardiac murmurs were detected in 32 (52 per cent). In both groups of dogs the prevalence of cardiac murmurs was low among dogs younger than three years (1.9 per cent) but increased with age (P < 0.001). The estimated ages at which 50 per cent of the dogs had developed murmurs were 7.5 and 6.2 years, respectively. When 39 of the 61 dogs were re-examined three years later, cardiac murmurs were detected in 28 (72 per cent), and the intensities of the murmurs had generally increased (P < 0.05). Nine (28 per cent) of the dogs which had previously had murmurs had been euthanased for signs of congestive heart failure whereas none of the dogs which had been free of murmurs had died from congestive heart failure. Animal insurance statistics from 1982 to 1990 (1983 excluded) for dogs less than 10 years old showed that claims for veterinary care or death or euthanasia were five times more common in the cavalier King Charles spaniel than in dachshunds (P < 0.001) and eight times more common than the mean for all other insured breeds (P < 0.001).  相似文献   
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