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101.
The effects of different grazing pressures (GPs) on soil properties are not sufficiently understood. The objectives were to analyse the effects of three different extensive GPs on stocks of soil organic C and total N, soil microbial biomass C, basal respiration and mineral N in three different soil depths of a long-term pasture in Central Germany (FORBIOBEN field trial). No significant (p ≤ 0.05) effects of GP on weighted stocks of soil organic C, total N, soil microbial biomass C, mineral N and basal respiration rate were observed, suggesting that the C and N cycles are coupled in the three grazing treatments. Oxalate soluble Fe contents explained a marked part of the variation of soil organic C (multiple linear regression: R2 = 0.64) and total N contents (R2 = 0.64) in the soils, whereas almost all of the variability of soil microbial biomass C contents and basal respiration was explained by soil organic C contents. Overall, variabilities of soil organic C and N contents were largely explained by oxalate soluble Fe contents, whereas grazing intensity did not affect the C and N dynamics.  相似文献   
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ObjectiveTo investigate the pharmacokinetics and effects of methadone on behaviour and plasma concentrations of cortisol and vasopressin in healthy dogs.Study designRandomized, cross-over, experimental trial.AnimalsNine adult dogs (beagle and beagle cross breeds), four males and five females.MethodsMethadone hydrochloride, 0.4 mg kg?1, was administered intravenously (IV) and subcutaneously (SC) with a crossover design. Drug and hormone analyses in plasma were performed using Liquid Chromatography–Electrospray Ionization–Tandem Mass Spectrometry and radioimmunoassay respectively. Behavioural data were collected using a standardized protocol.ResultsAfter IV administration, the plasma concentration of methadone at 10 minutes was 82.1 ± 9.2 ng mL?1 (mean ± SD), the terminal half-life was 3.9 ± 1.0 hours, the volume of distribution 9.2 ± 3.3 L kg?1 and plasma clearance 27.9 ± 7.6 mL minute?1 kg?1. After SC administration, time to maximal plasma concentration was 1.26 ± 1.04 hours and maximal plasma concentration of methadone was 23.9 ± 14.4 ng mL?1, the terminal half-life was 10.7 ± 4.3 hours and bioavailability was 79 ± 22%. Concentrations of both cortisol and vasopressin were increased for an hour following IV methadone. The observed behavioural effects of methadone were decreased licking and swallowing and an increase in whining after SC administration. The latter finding is notable as it can be misinterpreted as pain when methadone is used as an analgesic.Conclusion and clinical relevanceWhen methadone was administered by the SC route, the half-life was longer, but the individual variation in plasma concentrations was greater compared with IV administration. Increased frequency of whining occurred after administration of methadone and may be a drug effect and not a sign of pain. Cortisol and vasopressin concentrations in plasma may not be suitable for evaluating analgesia after methadone treatment.  相似文献   
104.
The regional scale variability of the bacterial community inhabiting the rhizosphere was studied with soil collected from maize fields located in the Santo Domingo Valley (SDV; Baja California Sur, Mexico), a semi-arid agricultural ecosystem of approximately 200 km2. The bacterial community structure was visualized by single-strand conformation polymorphism (SSCP) profiles of PCR-amplified partial 16S rRNA genes of directly extracted rhizosphere soil DNA. SSCP profiles of different SDV sites and an external field site in Germany were evaluated for their similarities and the contributing bacteria were characterized by DNA sequence analyses. SSCP profiles from each site were significantly different from the others, as revealed by permutation of pairwise similarities (P < 0.05). In comparison to the German site, SSCP profiles from SDV were more similar to each other despite contrasting soil salinity levels. Correspondence analysis revealed that among SDV sites, salinity levels, soil organic carbon and calcium (Ca2+) were most influential on the bacterial community structure. Depending on the phylogenetic group analyzed (Bacteria, Alphaproteobacteria, Pseudomonas), the importance of these soil variables varied. Interestingly, the East–West direction also revealed an effect, suggesting that future explorations of bacterial diversity patterns should also consider landscape topography in search of explaining patterns of bacterial diversity in soils.  相似文献   
105.
Topsoil (0–25 cm) and subsoil (30–55 cm) samples were taken from clay soil which had been cropped with reed canarygrass (Phalaris arundinacea). After crumbling the soil into fragments <10 mm and removing visible organic debris, CO2 evolution was measured in the laboratory at four moisture contents (17, 26, 36 and 50% H2O for the topsoil and 16, 23, 31 and 41% for the subsoil) and at constant temperatures of −4, 0.3, 5, 15, 25, and temperatures fluctuating (weekly) between −4 and +5°C. Evolution of CO2 after the addition of roots or stubble of P. arundinacea to the topsoil (25°C, 36% H2O) was also studied. The CO2 evolution increased significantly with temperature and moisture. The CO2 evolution rate per unit of soil carbon was about two times higher for topsoil than for subsoil. Temperature fluctuation between −4 and +5°C did not enhance CO2 evolution significantly compared with incubation at a constant 5°C and was even lower than or not significantly different from samples at 0.3°C.  相似文献   
106.
A novel approach, at least for laboratory conditions, for analysis of the dependence of soil C evolution on temperature is presented. A two-component (labile and refractory organic C) parallel first-order model was fitted to CO2 evolution rates from top- and subsoil, incubated at different combinations of temperature (constant −4, 0.3, 5, 15, 25, weekly fluctuating between −4 and +5°C) and moisture (17, 26, 36 and 50% H2O for the topsoil and 16, 23, 31 and 41% for the subsoil) and to the evolution of CO2 after the addition of roots or stubble of Phalaris arundinacea in the topsoil, measured at 25°C and 36% H2O (Lomander et al., 1998). The size of the pools and their respective first-order rate constants were optimized simultaneously by a least-squares method. The optimization was carried out separately for top- and subsoil. Quadratic functions were fitted to the temperature and moisture responses. For topsoil samples in which roots or stubble were added, a three-component model (labile, refractory and stubble or roots) was used. The initial partitioning of the soil C, the decomposition rate constants for each partition and the temperature and moisture responses were all assumed to be identical to those of pure topsoil, while the initial pool sizes of added roots and straw were measured. The calculated temperature at which CO2 evolution ceased (Tmin) was −0.83°C, and a recalculation to Q10-values resulted in increasing temperature response with decreasing temperature (Q10=2.2 at 25°C and 12.7 at 0.3°C). Simulated CO2 evolution rates agreed well with the measurements (Radj2=0.96 and 0.81) for top- and subsoil, respectively. The multi-compartment approach was superior to the single-compartment approach, which gave Radj2=0.88 and 0.76 for top- and subsoil, respectively. In general, CO2 evolution rates obtained from the laboratory experiment were higher than those measured in the field, even after differences in temperature and moisture were taken into account. After 300 d in the laboratory at 25°C and 36% H2O, 99% and 86% of the added straw and roots, respectively, had disappeared according to the described model. The CO2-evolution rate per unit of soil carbon was about two times higher for topsoil than for subsoil.  相似文献   
107.
The European College of Veterinary Pathologists (ECVP) was established in 1995 with the aim of advancing veterinary pathology and promoting high standards within the specialty in Europe. The ECVP is one of 21 European colleges recognized by the European Board of Veterinary Specialisation (EBVS), which represents a quality-assurance system for European veterinary specialists. Until the ECVP was founded, there was no unified European system recognizing the specialty of pathology, and many European countries followed their own qualification systems, which varied in form and standard. The ECVP provides an annual certifying examination, the passing of which is required to gain membership (diplomate status) in the college. This qualification is now accepted on equal terms by the well-established American College of Veterinary Pathologists (ACVP). In line with EBVS requirements, the ECVP has also established a standard continuing professional development (CPD) and re-registration system for its membership. Furthermore, it has promoted and unified European post-graduate training in veterinary pathology by setting up requirements for residency training programs and making registration and monitoring of these programs by the ECVP a prerequisite for approval of an institution as a training facility. The concurrent establishment, together with the European Society of Veterinary Pathology, of an annual summer school that trains residents for the certifying examination has further fostered European post-graduate training. Within 10 years, the ECVP has succeeded in establishing common standards and a unified approach to veterinary pathology throughout Europe. This article describes the evolution and organization of the ECVP.  相似文献   
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A selection of 164 monoclonal antibodies for determinants on porcine cells were tested on canine leukocytes by flow cytometry. Eighteen mAbs proved to be crossreacting and 16 of these reacted uniformly with cells of three unrelated dogs while two displayed a polymorphic reaction pattern.  相似文献   
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