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11.
C. Van Nieuwenhove R. Merckx Lieven Van Holm Karel Vlassak 《Biology and Fertility of Soils》2001,33(1):25-32
Azorhizobium caulinodans was directly inoculated onto rice plants in three short-term pot trials. Addition of increasing amounts of sucrose (23, 46,
92 kg ha–1) did not influence the N economy of the A. caulinodans-rice association during the early vegetative growth stage. A. caulinodans inoculation alone and in combination with the highest amount of sucrose had a significantly positive effect on the N balance,
with small but significant N gains in the system. Application of 60 kg urea-N ha–1 had a negative impact on the N economy of the inoculated treatments. N losses increased and the amount of atmospheric N2 fixed and incorporated decreased significantly as compared to the amounts under the 20 kg urea-N ha–1 regime. However, N losses were low – a maximum of 8% – at the early vegetative growth stage under the conditions of the experiments.
C limitation does not seem to be a limiting factor for the incorporation of fixed N2 in this bacteria-plant association. Biological N2 fixation caused by A. caulinodans inoculation was responsible for 14% of the plant N at the vegetative growth stage and under low N conditions.
Received: 30 January 2000 相似文献
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This study investigated the relationship between the current size of endangered bullhead (Cottus gobio) populations and microsatellite genetic variability. Additionally, the microsatellite data were used to evaluate whether a genetic test for population bottlenecks was able to provide evidence of recent severe population declines. Finally, our results were used to develop conservation priorities and measures. Population size appears to be a crucial parameter in determining the amount of genetic diversity that can be preserved in bullheads, since a significant positive correlation was observed between both variables. Furthermore, in some populations we were able to detect genetic signatures of the documented decline in population size. We suggest that the most immediate goal for bullhead conservation should be to increase the size and the range of the populations, and in doing so minimise or even reverse further genetic erosion. Potential management actions like habitat quality improvement, reduction of river fragmentation and supplementation programmes (translocation, supportive breeding) are discussed. 相似文献
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Paul Vanhaecke Lieven De Vrieze Wim Tackaert Patrick Sorgeloos 《Journal of the World Aquaculture Society》1990,21(4):257-262
Decapsulated Arremia cysts have been evaluated as a direct food source for larvae of the carp Cyprinus carpio L. All decapsulated cyst diets gave excellent survival of carp larvae during the first two weeks of culturing. Unlike traditionally brine-stored decapsulated cysts, dried Artemia embryos provided growth results comparable to those obtained with freshly hatched Artemia nauplii. Furthermore, except for Artemia embryos that lost their hatchability after long-term storage in air, several other inactivation treatments, simulating improper harvesting and processing of cysts, did not produce a significant decrease in the nutritional quality of the decapsulated cysts.
Using decapsulated cysts 89 a direct food source for carp larvae, instead of nauplii, the quantity of cysts needed can be reduced by about 25% to 35% after one and two weeks of culturing, respectively. Moreover, the use of decapsulated cysts advances the possible commercialition of poor-hatching and less expensive cyst products for culture of carp larvae. 相似文献
Using decapsulated cysts 89 a direct food source for carp larvae, instead of nauplii, the quantity of cysts needed can be reduced by about 25% to 35% after one and two weeks of culturing, respectively. Moreover, the use of decapsulated cysts advances the possible commercialition of poor-hatching and less expensive cyst products for culture of carp larvae. 相似文献
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This study investigated the placement of an intra-alveolar prosthesis of bone substitute on gingival/periodontal health in 5 ponies following repulsion of cheek teeth 108 and 208. In each pony, one randomly chosen alveolus was allowed to heal by second intention while the other was filled with a non-resorbable, biocompatible bone substitute. At 6, 12 and 24-months after surgery, both maxillary arches were evaluated for wear abnormalities and for gingival health using a periodontal scoring system. Recorded changes included development of overgrowths on mandibular cheek teeth, widening of maxillary interproximal spaces due to tooth drift with subsequent food accumulation, gingivitis, and subgingival pocket formation. Diastema formation initially occurred between the maxillary 06 and 07s but resolved after 24-months, whereas the diastemata that developed between the maxillary 09 and 10s remained. It was concluded that maxillary cheek teeth extraction induced progressive changes in the position of adjacent teeth that caused periodontitis. The use of a bone substitute prosthesis in the alveolus did not prevent the development of periodontal disease. 相似文献
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Van Meulebroek L Vanhaecke L De Swaef T Steppe K De Brabander H 《Journal of agricultural and food chemistry》2012,60(2):566-573
The growing interest of consumers in healthy food challenges growers to continuously improve the nutritional quality of their crops. In this research, the potential of a more saline growth environment for improved antioxidant concentration in tomato fruit was studied, and an U-HPLC-MS/MS method for the determination of lycopene, β-carotene, and α-tocopherol was optimized. Analytes were thereby separated on a 1.9 μm Hypersil GOLD C(18) column and quantified on a TSQ Vantage triple-quadropole mass spectrometer. The method displayed a short analysis time (6 min), a high specificity, and an excellent repeatability (≤6.39%). Furthermore, it was demonstrated that the electrical conductivity level of the applied nutrient solution did not unambiguously influence antioxidant concentration in tomato fruits. Future research should focus on moderate salt stress only and should aim at reducing natural variation by more closely controlling the growth environment and a more objective determination of the ripening degree. 相似文献
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Sara Torfs DVM Tamara Levet DVM Catherine Delesalle DVM PhD Jeroen Dewulf DVM Diplomate ECVPH Lieven Vlaminck DVM PhD Diplomate ECVS Frederik Pille DVM PhD Diplomate ECVS Laurence Lefere DVM Ann Martens DVM PhD Diplomate ECVS 《Veterinary surgery : VS》2010,39(5):616-620
Objective: To assess risk factors for celiotomy incisional infection in horses, especially the use of staples for skin closure. Study Design: Case series. Animals: Horses (n=356) that had 1 exploratory celiotomy for colic and survived >2 weeks after surgery between March 1, 2004 and December 31, 2007. Methods: Incisions were classified as “normal” (no complication, only edema, serous drainage lasting <24 hours) or as “surgical site infection (SSI)” (persistent serosanguinous drainage or purulent drainage with or without positive bacterial culture). All possible risk factors, including method of skin closure (monofilament sutures or staples), were statistically analyzed using univariate and multivariate logistic regression. Results: Of 356 horses, 303 (85%) had normal wound healing and 53 (15%) developed a SSI (purulent: 48 [14%]; persistent serosanguinous: 5 [1%]). Bacterial cultures were positive in 33 of 40 cases. Factors significantly associated with SSI in the multivariate analysis were: use of staples for skin closure (odds ratio [OR] 3.85, P<.001) and surgical site closure by a 1st or 2nd year resident (OR 2.20, P=.016). Lavage of the linea alba with sterile saline solution after closure was a protective factor (OR 0.38, P=.004). Conclusion: Use of staples for skin closure and less experienced surgeons closing the abdomen are risk factors for incisional infection. Incisional lavage after linea alba closure was a protective factor. Clinical Relevance: Despite their ease and speed of application, skin staples can lead to an increase in celiotomy wound complications in horses. 相似文献
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Besides finishing pigs, sows are also believed to be important in the epidemiology of Salmonella. The study objective was to investigate the prevalence of Salmonella excretion in sows during an entire reproductive cycle. In 3 farrow-to-finish herds, groups of 34, 40 and 32 sows, respectively, were sampled serially. Faecal samples, environmental swabs and feed samples were taken and submitted to a qualitative Salmonella isolation. All isolates were characterised using RAPD and a representative number of isolates was serotyped. The prevalence of Salmonella excretion was < 10% during gestation, around farrowing and during lactation, but a significant increase in the number of Salmonella excreting sows was found in herds A (p < 0.01) and C (p = 0.02) after weaning. S. Infantis was the most prevalent serotype in herd A, S. Derby in herds B and C. Except for the S. Infantis group in herd A, all isolates within each group of the RAPD analysis belonged to the same serotype. Three sows in herd A and 1 sow in herd C shed different serotypes at different time points. The present results indicate that sows can maintain Salmonella infections in farrow-to-finish herds and that culled sows, leaving the herd after weaning, may constitute a substantial risk for contamination of their carcasses with Salmonella. 相似文献
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Vlaminck L Hoegaerts M Steenhaut M Maes D Saunders J Gasthuys F 《Veterinary journal (London, England : 1997)》2008,175(2):249-258
The aim of the study was to investigate post-extraction tooth drift in ponies and the influence of an intra-alveolar prosthesis. The maxillary 08 was bilaterally repulsed in five ponies under general anaesthesia. On one side the alveolus was left to granulate, and on the other a synthetic bone substitute prosthesis was fitted. Standard radiographic projections of the head were taken monthly during the first year and at 24 months post-operatively. Different cephalometric parameters were measured and statistically analyzed. Rostral and caudal drift were recognized in molar and premolar teeth, respectively. The prosthesis significantly slowed down tooth drift (P<0.001). Although differences in the degree of secondary mandibular overgrowths (on 06s, 11s and 08s) were found between treatments, this had no important clinical consequences. Premolars showed significantly more tooth wear in comparison with molars (P<0.001). Tooth attrition was higher in the prosthesis treated sides (P<0.001). 相似文献