Increased expression of endothelin B receptor in static stretch exposed porcine mitral valve leaflets     

Pedersen LG  Zhao J  Yang J  Thomsen PD  Gregersen H  Hasenkam JM  Smerup M  Pedersen HD  Olsen LH 《Research in veterinary science》2007,82(2):232-238

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Long-Term Changes in Forest Growth: Potential Effects of Nitrogen Deposition and Acidification     

Nellemann  Christian  Thomsen  Mette Goul 《Water, air, and soil pollution》2001,128(3-4):197-205

In spite of numerous experimental studies, it has, sofar, not been possible to link historic changes inforest growth to acid deposition at regional scales,partly due to difficulties in modeling the ecologicalcomplexity of forests. We analyzed radial incrementdata from increment cores from >31 000 spruce forestplots in southern Norway from 1954–1996. Using acombination of a bio-stratification model to controlconfounding factors, and a catchment model foracidification, we demonstrate for the first time aspatial and temporal co-variation between forestgrowth and both nitrogen deposition and acidification,as indicated by acidity critical loads exceedances.Increases in growth during the 1960–1970s, followed bya subsequent decline in the 1980–1990s, were bestexplained by combined actions of acidification,nitrogen deposition and climatic stress on forestgrowth. While forest conditions varyprimarily with natural growing conditions, the resultssuggest that boreal forests are sensitive to moderatelevels of nitrogen and sulphur deposition whereacidity critical loads are low, and that effects maybe observed over relatively short time scales.  相似文献   

A study of the dynamics of digital dermatitis in 742 lactating dairy cows     

Nielsen BH  Thomsen PT  Green LE  Kaler J 《Preventive veterinary medicine》2012,104(1-2):44-52

Digital dermatitis (DD) is a contagious disease of cattle affecting the skin of the claw. The disease presents with a range of severities and can be associated with lameness. Information about the disease dynamics of DD is scarce. Parity and lactation stage have been identified as risk factors for DD and studies have also indicated that not all cows are equal regarding their risk of recurrent disease and prospects for cure from DD. The aim of this study was to investigate host heterogeneity to DD and to identify disease patterns of DD and factors associated with the development and resolution of lesions. In three commercial dairy herds, 742 lactating cows were observed for DD lesions weekly for 11 or 12 weeks. The effects of parity, lactation stage and duration of preceding episode on the hazard of transitions between healthy and lesion states were analysed using a multilevel multistate discrete-time model. One or more DD lesions were observed in 460 cows and lesions were observed in 2426 out of 10,585 observations. In total, 1755 uncensored episodes with DD lesions were observed. Early lactation was associated with a reduced risk of developing lesions compared with mid and late lactation. Lesions that developed in late lactation had a greater likelihood of resolution compared with lesions that developed during early lactation. There was a reduced risk of lesions developing in parity 3 compared with parity 1 cows, but an increased risk of lesions developing in parity 2 compared with parity 1 cows. In the present study, the mean duration of uncensored DD episodes was 1.7 weeks indicating that the duration of the majority of DD lesions might be shorter than the 42 days reported previously. The transitions between disease states suggest that DD is a dynamic disease, and that the early stage lesions are more transient than expected from previous studies. We conclude that studies with shorter observation intervals than one week are needed to fully understand and describe the individual and group dynamics of DD.  相似文献   

Pharmacokinetics of intra‐articular morphine in horses with lipopolysaccharide‐induced synovitis     

Casper Lindegaard  Anna B Frost  Maj H Thomsen  Claus Larsen  Steen Honoré Hansen  Pia Haubro Andersen 《Veterinary anaesthesia and analgesia》2010,37(2):186-195

ObjectiveTo describe the pharmacokinetics of intra-articularly (IA) administered morphine.Study designExperimental randomized, cross-over study.AnimalsEight adult healthy mixed breed horses aged 6.5 ± 2.3 (mean ± SD) years and weighing 535 ± 86 kg.MethodsUnilateral radiocarpal synovitis was induced by IA injection of 3 μg lipopolysaccharide (LPS) on two occasions (right and left radiocarpal joint, respectively) separated by a 3-week wash-out period. Treatments were administered 4 hours post-LPS-injection: Treatment IA; preservative free morphine IA (0.05 mg kg^?1) plus saline intravenous (IV) and treatment IV; saline IA plus preservative free morphine IV (0.05 mg kg^?1). Concentrations of morphine, morphine-3-glucuronide and morphine-6-glucuronide (M6G) were determined repeatedly in serum and synovial fluid (SF) by high-performance liquid chromatography mass spectrometry, at 2 and 4 hours and then at 4 hours intervals until 28 hours post-treatment.ResultsInjection of LPS elicited a marked and comparable synovitis in all LPS-injected radiocarpal joints. IA administered morphine was detectable in SF of all eight joints 24 hours post-treatment and in 6/8 joints 28 hours post-treatment. The terminal half-life of morphine in SF was estimated to be 2.6 hours. IA administration of morphine resulted in mean serum concentrations of morphine below 5 ng mL^?1 from 2 to 28 hours after treatment.Conclusions and clinical relevanceIntra-articularly administered morphine remained within the joint for at least 24 hours. At the same time only very low serum concentrations of morphine and M6G were detected. The present results suggest that IA morphine at 0.05 mg kg^?1 may be used for IA analgesia lasting at least 24 hours and give strong support to the theory that previously observed analgesic and anti-inflammatory effects of IA morphine in horses are most likely to be mediated peripherally.  相似文献   

Estimating soil C loss potentials from the C to N ratio     

Ingrid K. Thomsen  Bjørn M. Petersen  Sander Bruun  Lars S. Jensen  Bent T. Christensen 《Soil biology & biochemistry》2008,40(3):849-852

Thirty-seven arable soil samples (0–20 cm depth) ranging in clay content from 4 to 40% and in C to N ratio from 8 to 20 were incubated at ?100 hPa and 20 °C for 238 days. The CO₂-C evolved during days 105–147 and days 0–238 was related to the soil C to N ratio by a power function. We hypothesized the existence of a threshold value for the soil C to N ratio below which CO₂-C evolution remains constant. A soil C to N threshold value of 9.7 was estimated for both incubation periods and the function predicted that the CO₂-C evolution was halved when the soil C to N ratio approached 14. Data obtained by Springob and Kirchmann [Springob, G., Kirchmann, H., 2002. C-rich sandy Ap horizons of specific historical land-use contain large fractions of refractory organic matter. Soil Biology & Biochemistry 34, 1571–1581.] showed a similar relationship, but with a C to N threshold value of 10.8. We suggest that the relationship established between the C to N ratio of a soil and its CO₂-C loss during incubation represents a simple but useful measure for predicting soil C loss potentials on a more general level.  相似文献   

Nitrous oxide evolution from structurally intact soil as influenced by tillage and soil water content     

Søren O. Petersen  Per Schjønning  Ingrid K. Thomsen  Bent T. Christensen 《Soil biology & biochemistry》2008,40(4):967-977

Among farmers there is a growing interest for adoption of reduced tillage practices, which has accentuated the need to understand the consequences for soil nutrient dynamics and losses. A laboratory study was conducted with structurally intact soil cores collected from two depths, 0–4 and 14–18 cm, within tillage experiments on contrasting soil types, both experiments with soil under mouldboard ploughing (MP) or shallow tillage (ST). The soil cores were adjusted to one of seven matric potentials ranging from ?1500 to ?15 hPa. The extent and regulation of nitrous oxide (N₂O) evolution as a function of tillage, depth and soil characteristics was studied by measurement of N₂O and CO₂ evolution rates, as well as nitrifying and denitrifying potentials, and subsequent data analysis by multiple linear regression models. At both sites, compaction of ST soil below the depth of tillage was significant. The vertical distribution of N₂O evolution was different in MP and ST soil, but no main effect of tillage on N₂O evolution was observed. Effects of soil variables on N₂O evolution were analysed using volumetric water content, water-filled pore space, or relative gas diffusivity (RD) to represent the effect of soil water. Using RD weakened interactions with tillage and C availability and strengthened main effects, suggesting that RD may provide a more general representation of the water effect. At 0–4 cm depth, N₂O evolution was related to NO₃^? availability in the soil with 5.1% C, but to C availability in the soil with 1.5% C. The contrasting patterns of dependencies in the different environments support the interpretation of reduced tillage and soil water content as indirect controls, via diffusional constraints, of N₂O evolution.  相似文献   

Zur Biologie derHoplocampa testudinea Kl     

Mathias Thomsen 《Journal of pest science》1929,5(7):80-84

Ohne Zusammenfassung Mit 7 Abbildungen.  相似文献   

Effects of interleukin-1 alpha on migration of canine neutrophils in vitro and in vivo     

M K Thomsen  H K Thomsen 《Veterinary immunology and immunopathology》1990,26(4):385-393

Inflammatory cell activation by interleukin-1 (IL-1) has been the subject of studies in laboratory animals and man, and was the aim of the present study. At physiological concentrations of 0.01-100 units/ml, human recombinant IL-1 alpha was shown to be a chemokinetic and chemotactic agent for canine neutrophils in vitro and to cause dose-dependent and selective neutrophil infiltration following intradermal injection of 1 or 250 units. The findings support a putative role for IL-1, and IL-1-induced products such as IL-8, as mediator of immunoinflammatory reactions in which neutrophil infiltration is prominent.  相似文献   

A pulmonary adenoma in an Australian sheep     

PT HOOPER  KA ELLARD 《Australian veterinary journal》1995,72(12):477-477

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Sickness, mortality and the buller steer syndrome in a western Canadian feedlot     

LF TAYLOR  CW BOOKER  GK JIM  PT GUICHON 《Australian veterinary journal》1997,75(10):732-736

Objective To determine if an association existed between sickness, mortality and bullers in a western Canadian feedlot.
Design A retrospective epidemiological study.
Animals 78,445 male cattle that entered a 24,000-head feedlot in western Canada from 1991 to 1993.
Procedure Animal health records for bullers were collected and analysed to see if they were at greater risk of sickness and mortality than other steers, and to see if pens with a high prevalence of bullers also had a high prevalence of sickness and mortality.
Results The prevalence of bullers increased with increasing age of cattle on arrival at the feedlot (R = 0.36; P < 0.001). Sickness and mortality decreased with increasing age of cattle on arrival. However, sickness and mortality in bullers relative to other steers actually increased with increasing age on arrival suggesting an interaction existed between sickness and bullers. Bullers were significantly (P < 0.05) more likely to get sick and to die than other steers. In all cases, there was a strong temporal association between sickness and bullers, with sickness and bullers mostly occurring within the first 30 days of the feeding period. On average, pens of cattle with a high prevalence of bullers did not have a correspondingly high prevalence of sickness or mortality.
Conclusion This study suggests that sickness is an effect modifier of dominance behaviour and therefore bullers in feedlot steers. Bullers should always be checked for signs of sickness and treated accordingly. Further research is needed to investigate the effects of sickness on dominance behaviour in pens of feedlot cattle.  相似文献