Carbon‐mineralization kinetics in an organically managed Cambic Arenosol amended with organic fertilizers     

Henrique M. Ribeiro  David Fangueiro  Fátima Alves  Ernesto Vasconcelos  João Coutinho  Roland Bol  Fernanda Cabral 《植物养料与土壤学杂志》2010,173(1):39-45

The dynamics of C mineralization in an organically managed Cambic Arenosol amended with hen manure, a stabilized compost (compost), and three different combinations of both fertilizers (varying from a 1:100 to a 1:10 ratio) were studied during an incubation experiment to estimate the potential of such combinations to preserve/restore soil C content relative to single applications. A strong increase of the CO₂‐C emissions relative to the unamended soil (control) was observed after soil application of all five organic‐fertilizer treatments. A significantly higher amount of applied C was lost in hen‐manure treatment (648 mg CO₂‐C [g C applied]^–1) when compared to compost (159 mg CO₂‐C [g C applied]^–1) or to the three combined treatments (176–195 mg CO₂‐C [g C applied]^–1). The first‐order exponential model and the double exponential model were used to fit the C‐mineralization data in the treatments considered. Results showed that mixing “small” amounts of hen manure with compost did not affect the total amount of potentially mineralizable C, but significantly increased the mineralization rate constant. Clearly, combinations of both fertilizers promoted an initial faster mineralization of the organic matter, and consequently a faster release of nutrients, without affecting the total amount of C sequestered in soil.  相似文献   

Dual isotope and isotopomer measurements for the understanding of N2O production and consumption during denitrification in an arable soil     

A. Meijide  L. M. Cardenas  R. Bol  A. Bergstermann  K. Goulding  R. Well  A. Vallejo  D. Scholefield 《European Journal of Soil Science》2010,61(3):364-374

The aim of our research was to obtain information on the isotopic fingerprint of nitrous oxide (N₂O) associated with its production and consumption during denitrification. An arable soil was preincubated at high moisture content and subsequently amended with glucose (400 kg C ha^?1) and KNO₃ (80 kg N ha^?1) and kept at 85% water‐filled pore space. Twelve replicate samples of the soil were incubated for 13 days under a helium‐oxygen atmosphere, simultaneously measuring gas fluxes (N₂O, N₂ and CO₂) and isotope signatures (δ¹⁸O‐N₂O, δ¹⁵N^bulk‐N₂O, δ¹⁵N^α, δ¹⁵N^β and ¹⁵N site preference) of emitted N₂O. The maximum N₂O flux (6.9 ± 1.8 kg N ha^?1 day^?1) occurred 3 days after amendment application, followed by the maximum N₂ flux on day 4 (6.6 ± 3.0 kg N ha^?1 day^?1). The δ¹⁵N^bulk was initially ?34.4‰ and increased to +4.5‰ during the periods of maximum N₂ flux, demonstrating fractionation during N₂O reduction, and then decreased. The δ¹⁸O‐N₂O also increased, peaking with the maximum N₂ flux and remaining stable afterwards. The site preference (SP) decreased from the initial +7.5 to ?2.1‰ when the N₂O flux peaked, and then simultaneously increased with the appearance of the N₂ peak to +8.6‰ and remained stable thereafter, even when the O₂ supply was removed. We suggest that this results from a non‐homogenous distribution of NO in the soil, possibly linked to the KNO₃ amendments to the soil, causing the creation of several NO pools, which affected differently the isotopic signature of N₂O and the N₂O and N₂ fluxes during the various stages of the process. The N₂O isotopologue values reflected the temporal patterns observed in N₂O and N₂ fluxes. A concurrent increase in ¹⁵N site preference and δ¹⁸O of N₂O was found to be indicative of N₂O reduction to N₂.  相似文献   

Uptake Studies on a Fluorescein-Labelled Seed Oil Adjuvant in Abutilon theophrasti, Sinapis arvensis and Beta vulgaris     

Julia Heini  Victor Rueda Ayala  Frank Walker  Hans-Georg Mainx  Roland Gerhards 《Gesunde Pflanzen》2012,64(4):167-174

Though adjuvants are abundant in almost every pesticide solution, their mode of action is still not completely clear. Studies on their way through the cuticle are quite difficult due to a lack of radiolabelled surfactants. In this study we want to present the results of an experiment conducted to evaluate the mode of action of an ethoxylated soybean oil (ESBO) adjuvant. To evaluate the route of ESBO through the cuticle it was labelled with fluorescein and applied to one leaf of different test species (Abutilon theophrasti, Sinapis arvensis and Beta vulgaris). Treated leaves were harvested and rinsed with either deionised water, methanol/water or chloroform. The fluorescein content of washed leaves and the solution in which they were washed were analysed with High-Performance Liquid Chromatography (HPLC) coupled with an UV detector. Results lead to the assumption that ESBO passed through the cuticle. If this holds true, ESBO was able to reach the underlying cell tissue where it might have been metabolised or even translocated to other plant parts. Though a lot of research has to be conducted on the mechanism and mode of action of adjuvants, this study gives an approach to investigate the behavior of foliar applied adjuvants.  相似文献   

Methods for determining the vapour pressure of active ingredients used in crop protection. Part IV. An improved thermogravimetric determination based on evaporation rate     

Walter Gückel  Roland Kstel  Thomas Krhl  Adolf Parg 《Pest management science》1995,45(1):27-31

The vapour pressure of thermally stable substances can be determined easily at ambient pressure using the evaporation rate method. It is possible to measure the evaporation by thermogravimetry in the temperature range from 30°C to 800°C. Vapour pressures as low as 10^?10 Pa (10^?12 mbar) can be determined with excellent reproducibility.  相似文献   

Biochemical analysis, cpn60 and 16S rDNA sequence data indicate that Streptococcus suis serotypes 32 and 34, isolated from pigs, are Streptococcus orisratti     

Hill JE  Gottschalk M  Brousseau R  Harel J  Hemmingsen SM  Goh SH 《Veterinary microbiology》2005,107(1-2):63-69

Streptococcus suis serotypes have traditionally been identified by morphology, biochemical profiling and serotyping. Analysis of the sequences of 16S rRNA and cpn60 genes of the 35 characterized serotypes of S. suis led to the observation that two serotypes 32 and 34, are significantly distinct from other S. suis serotypes and may represent a distinct species. Here we present DNA sequence data and biochemical profiles which indicate that S. suis serotypes 32 and 34, isolated from pigs, are clustered with Streptococcus orisratti, a Voges-Proskauer negative, alpha-haemolytic, aesculin-hydrolytic, Lancefield group A streptococcus isolated from the teeth of rats.  相似文献   

Elimination of persistently BVDV infect animals: efficient herd screening using RT-PCR and antigen ELISA in milk and serum samples     

Gaede W  Gehrmann B  Körber R 《Berliner und Münchener tier?rztliche Wochenschrift》2003,116(5-6):234-239

With the long-term perspective of the eradication of BVD/MD in the German federal state Saxony-Anhalt a voluntary control program was initiated in 2002 by an administrative regulation based on federal German guidelines. The short-term aim of this program is the establishment of BVDV-unsuspected herds achieved by elimination of persistently infected cattle. The diagnostic program and particularly the choice of the diagnostic tools was based on the consideration of laboratory experiences as well as on economic and logistic aspects. A combination of RT-PCR and antigen-ELISA was found to be the suitable diagnostic methods. The screening started with examinations of sera pools using Real Time RT-PCR in the Light-Cylcer system. After positive pool results the individual persistently infected animals were detected using various commercial ERNS-antigen-ELISAs. The RT-PCR revealed a high degree of sensitivity and robustness. With respect to highly specific ELISAs the producers have to ensure the detection of all currently important virus strains. The prevalence of persistently infected animals in the cattle population of Saxony-Anhalt was about 0.2% during the last 3 years. This is probably due to nearly 10 years of broad vaccination and will prove advantageous for BVDV elimination.  相似文献   

Randomized controlled trial of the efficacy of cyclosporine in the treatment of atopic dermatitis in dogs     

Olivry T  Steffan J  Fisch RD  Prélaud P  Guaguère E  Fontaine J  Carlotti DN;European Veterinary Dermatology Cyclosporine Group 《Journal of the American Veterinary Medical Association》2002,221(3):370-377

OBJECTIVE: To evaluate efficacy of cyclosporine A, administered at either of 2 dosages, in dogs with atopic dermatitis (AD). DESIGN: Multicenter randomized controlled trial. ANIMALS: 91 dogs with AD. PROCEDURE: Dogs were assigned to receive placebo (30 dogs), cyclosporine at a low dosage (2.5 mg/kg [1.1 mg/lb], PO, q 24 h for 6 weeks; 30 dogs), or cyclosporine at a high dosage (5.0 mg/kg [2.3 mg/lb], PO, q 24 h for 6 weeks; 31 dogs). RESULTS: After 6 weeks, mean percentage reductions, compared with baseline scores, in scores of lesion severity were 34, 41, and 67% for dogs treated with the placebo, cyclosporine at the low dosage, and cyclosporine at the high dosage, respectively. Similarly, mean percentage reductions in pruritus scores were 15, 31, and 45%, respectively. Percentage reductions in skin lesion and pruritus scores were significantly higher for dogs given cyclosporine at the high dosage than for dogs given the placebo. Treatment efficacy was significantly associated with whether dogs had a history of seasonal AD. Percentage reductions in skin lesion and pruritus scores were high for dogs treated with cyclosporine at the highest dosage that had a history of nonseasonal AD. Dogs in all groups with seasonal AD improved during the study period. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that oral administration of cyclosporine at a dosage of 5.0 mg/kg once daily is effective in reducing severity of pruritus and skin lesions in dogs with AD, especially those with nonseasonal disease.  相似文献   

Classical swine fever virus induces activation of plasmacytoid and conventional dendritic cells in tonsil, blood, and spleen of infected pigs   总被引：1，自引：0，他引：1  

Jamin A  Gorin S  Cariolet R  Le Potier MF  Kuntz-Simon G 《Veterinary research》2008,39(1):7

Classical swine fever virus (CSFV) compromises the host immune system, causing indirect leucopoenia and disruption of in vitro T cell stimulation capacity. In order to explore the potential role of dendritic cells (DC) in such phenomena, the activation of conventional DC (cDC) and plasmacytoid DC (pDC) in blood and secondary lymphoid organs of infected pigs was investigated in the early time course post-inoculation (pi), together with viral components dissemination and cytokine production in serum. Whereas CD11R1+CD172a+ cDC frequencies were markedly reduced in blood and spleen, analysis of CD4+CD172a+ pDC numbers revealed a rapid turn-over of this DC subset in tissues pi. Both subsets matured and were activated after infection, as demonstrated by down-regulation of CD1a, up-regulation of the co-stimulation molecule CD80/86 and expression of cytokines. cDC essentially expressed tumor necrosis factor alpha (TNF-alpha) and interleukin (IL)-10, whereas pDC produced alpha interferon (IFN-alpha) and IL-12. IFN-alpha and TNF-alpha productions revealed an enhancement of innate anti-viral immune responses. Detection of antigen activated B lymphocytes in tonsil T-cell areas at 72 h pi, subsequently to the transient translocation of the viral E2 protein within germinal centres at 48 h pi, indicates the initiation of humoral response. This response was also evidenced by an important IL-10 production in serum one week pi. IL-12 expression in organs, as well as transient detection of IL-18 and IFN-gamma in serum, reflected the initiation of cellular immune responses. However, the uncommonly high levels of TNF-alpha and IFN-alpha produced by DC and measured in serum early post-infection, together with IL-10 expression in spleen, could play a role in the disruption of immune system cells, either inducing apoptosis or impairing DC functionalities themselves.  相似文献   

What the practicing veterinarian should know about rat bite fever     

Abma R  Boer H  Douma G  van Hoeck B  Lipman L  Gaastra W 《Tijdschrift voor diergeneeskunde》2008,133(16):668-670

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Dorsal 80° proximal 30° lateral-palmarodistal medial oblique view for screw fixation of the accessory carpal bone     

Thomas Launois DVM  Lieve Vandekeybus DVM  Francis Desbrosse DVM  ECVS  Roland Perrin DVM  ECVS 《Journal of Equine Veterinary Science》2002,22(6):265

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