Serodiagnosis and monitoring of contagious bovine pleuropneumonia (CBPP) with an indirect ELISA based on the specific lipoprotein LppQ of Mycoplasma mycoides subsp. mycoides SC.

An indirect ELISA, based on the specific and strongly antigenic recombinant peptide of the N'-terminal half of the lipoprotein LppQ from Mycoplasma mycoides subsp. mycoides small colony type (SC) was developed for the detection of antibodies to M. mycoides subsp. mycoides SC. It was evaluated for its suitability for serodiagnosis and monitoring of contagious bovine pleuropneumonia (CBPP). The recombinant peptide containing poly-histidine residue tails was expressed in Escherichia coli and subsequently purified by Ni(2+) chelate affinity chromatography to be used as antigen to coat microtiter ELISA plates. The specificity of the antigen was tested against rabbit hyperimmune sera directed against related Mycoplasmas of the M. mycoides cluster and with sera from cattle that were either free of CBPP, but suffered from other mycoplasmal infections such as M. bovis, or showed cross-reactions in the complement fixation test. The sensitivity of the ELISA was assessed with sera from artificially infected animals and with sera from cattle originating from areas where CBPP was endemic at the time of blood sampling. The study revealed that the ELISA was both specific and sensitive for CBPP positive bovine sera and was shown also to be robust to harsh climatic conditions.     

Stoffkonzentrationen in bodenlösungen bei verschiedenen fruchtfolgen auf einem sandigen standort 2. mitteilung: Nitratverlagerung

In einem komplexen Feldversuch auf einem sandigen Standort wurde über einen Zeitraum von 5 Jahren in verschiedenen Fruchtfolgen die Wirkung unterschiedlicher Bodenbearbeitung und Mineral‐N‐Düngung auf die Nitratkonzentration in Bodenlösungen mit Hilfe einer Saugkerzenanlage untersucht. Die Nitratkonzentrationen in Bodenlösungen (60 cm Tiefe) wurden untersucht und die potentielle N‐Fracht auf der Grundlage der Nitratkonzentration im Bodenwasser und der klimatischen Wasserbilanz kalkuliert.

Die Nitratkonzentrationen in Bodenlösungen folgten einer ausgeprägten jahreszeitlichen Dynamik, mit Maxima in der Hauptsickerperiode und Minima in der Vegetationszeit, wobei die Wirkung der Prüffaktoren in folgender Reihenfolge abnahm: Mineral‐N‐Düngung > Fruchtfolge > Bodenbearbeitung.

In der Hauptsickerperiode wurde > 50% der jährlichen Sickerwassermenge und 36 . . . 94% der N‐Fracht ermittelt. Auf dem Untersuchungsstandort betrugen die maximalen N‐Frachten ca. 100 kg ha^?1a^?1.

Die N‐Frachten wurden durch die N‐Entzüge der verschiedenen Fruchtarten beeinflusst. Durch mineralische N‐Düngung stiegen die N‐Entzüge von Wintergetreide um 42 . . . 85% und von Silomais um 32 . . . 53%.     

Environmental conditions,and phenolic compounds potential in the leaves of Vitis tiliifolia Humb. & Bonpl. ex Schult.

Genetic Resources and Crop Evolution - The wild vine Vitis tiliifolia (Humb & Bonpl. Ex Schult.). is found in Mexico, Central América, and the Caribbean region. In the Veracruz State,...     

Field and laboratory investigations of Lumbricus badensis ecology and behaviour

正Dear Editor,Deep burrowing and soil surface feeding earthworms,so-called strict-anecic and epi-anecic species (Hoeffner et al., 2019), are a highly influential soil faunal group in many natural and manmade environments. Typically, they are relatively large and contribute substantially to the formation and processes of mull-type soils through effective foraging and incorporation of plant litter (Edwards and Bohlen,     

Comparison of three different methods to prevent heat loss in healthy dogs undergoing 90 minutes of general anesthesia

ObjectiveTo compare a towel under, a warm water pad under or a forced warm air blanket over dogs as techniques to reduce heat loss during a standardized anesthetic.Study designProspective, randomized, crossover study.AnimalsEight, healthy, mixed breed dogs weighing 16.3–19.6 kg.MethodsDogs were anesthetized four times for 90 minutes. Dogs were placed on a steel table (treatment TA), with a cotton towel (treatment TO) or a circulating warm water pad (treatment WP) between the dog and the table, or with, a towel under the dog and covered with a forced warm air blanket (treatment WAB). Rectal temperature (RT) was recorded at 5 minute intervals. Changes in temperature (ΔRT) were calculated as the RT at a given point subtracted from the RT before anesthesia (baseline) and compared over time.ResultsAfter 90 minutes of anesthesia, the ΔRT was 3.42 °C ± 0.29 for TA, 2.78 °C ± 0.43 for TO, 1.98 °C ± 0.29 for WP, and 0.91 °C ± 0.27 for WAB. Significant differences in ΔRT occurred between TA and WAB at 20 minutes (0.94 °C ± 0.42, p = 0.0206), between TO and WAB at 30 minutes (1.16 °C ± 0.62, p = 0.0063), between WP and WAB at 50 minutes (0.96 °C ± 0.98, p = 0.0249), between TA and WP at 35 minutes (1.19 °C ± 0.54, p = 0.0091), between TO and WP at 70 minutes (1.12 °C ± 0.56, p = 0.0248), and between TA and TO at 75 minutes (0.96 °C ± 0.62, p = 0.0313). These differences in ΔRT between each treatment persisted from the times indicated until the end of the anesthesia.Conclusion and clinical relevanceDuring anesthesia, forced warm air blankets were superior to other methods tested for limiting heat loss. An efficient heat loss technique should be used for anesthesia longer than 20 minutes duration in medium sized dogs.     

The effect of fire severity on first-year seedling establishment in a <Emphasis Type="Italic">Pinus canariensis</Emphasis> forest on Tenerife,Canary Islands

The Canarian pine (Pinus canariensis) exhibits a striking combination of high adult resistance to fire and intermediate serotiny. Hence, the study of its post-fire regeneration can support valuable new insights about functional adaptations to fire. Here, we analyse the first-year seedling establishment after fire in a P. canariensis forest on the northern slope of Tenerife, Canary Islands. The effects of fire severity and other explanatory variables on the seedling density recorded 9 months after fire were examined. We detected a clear unimodal relationship between seedling density and fire severity, with maximum regeneration associated with intermediate fire severity and no regeneration associated with very high crown damage. The results suggested that high severity fires may have caused the partial destruction of the aerial seed bank and/or the creation of unfavourable seedbed conditions for germination and seedling emergence. The density of large pine trees, reflecting seed availability, was the second most important factor explaining the distribution of seedlings. Cover of scorched needle litter on the ground correlated strongly and positively with pine seedling density and negatively with fire severity. The complete lack of regeneration at sites most strongly affected by fire does not represent a major threat for the stand recovery of the Canarian pine, due to the very high tree resistance to fire and the tremendous capacity of the Canarian pine to resprout after fire. The observed very high seedling densities at sites with intermediate fire impacts can probably be related to both the complete liberation of the seed bank (including seeds stored in serotinous cones) and favourable micro-environmental conditions for seed germination and seedling establishment.     

Leaf area of beech (<Emphasis Type="Italic">Fagus sylvatica</Emphasis> L.) from different stands in eastern Austria studied by randomized branch sampling

Few tree size/leaf area correlations have been produced for hardwoods, where the extrapolation from individual branches to the whole tree is less straightforward than in conifers with more regular branching patterns. We used randomized branch sampling to estimate leaf area of European beech (Fagus sylvatica L.) trees of different stands, ages and areas in Austria. Cross-sectional areas (CSA) predicted 87–92% of leaf area variation, the best predictor being the sum of branch CSA. Leaf area was somewhat better correlated with CSA at breast height than at the base of the crown, and using sapwood instead of total CSA made little difference. While there was no effect of growth area, a stepwise regression model showed that dominant trees in pole-stage had, for unclear reasons, significantly higher leaf area/CSA relationships. A comparison with regressions produced from smaller beech trees in other parts of Europe suggests that the leaf area/basal area regression is generally valid for beech in central Europe.     

Leaching Methods Can Underestimate Mineralization Potential of Soils

Aerobic incubations to estimate net nitrogen (N) mineralization typically involve periodic leaching of soil with 0.01 M calcium chloride (CaCl₂), so as to remove mineral N that would otherwise be subject to immobilization. A study was conducted to evaluate the accuracy of leaching for analysis of exchangeable ammonium (NH₄⁺)-N and nitrate + nitrite (NO₃^?+ NO₂^–)-N, relative to conventional extractions using 2 M potassium chloride (KCl). Ten air-dried soils were used, five each from Illinois and Brazil, that had been amended with NH₄⁺-N (1 g kg^?1) and NO₃^–-N (0.6 g kg^?1). Both methods were in good agreement for inorganic N analysis of the Brazilian Oxisols, whereas leaching was significantly lower by 12–48% in recovering exchangeable NH₄⁺-N from Illinois Alfisols, Mollisols, and Histosols. The potential for underestimating net N mineralization was confirmed by a 12-wk incubation experiment showing 9–86% of mineral N recoveries from three temperate soils as exchangeable NH₄⁺.     

Nitrogen requirement of fodder and sugar beet (Beta vulgaris L.) cultivars under high-yielding conditions of northwestern Europe

This study provides current data on plant nitrogen (N) uptake required for maximum sugar yield (PNUp_max) and the corresponding fertilizer N dose (ND) (optimum N dose [ND_opt]) for high-yielding beet crops (sugar yield up to 20 Mg ha^?1). In 2010 and 2011, field experiments were conducted with four cultivars from Beta genus differing in dry matter composition, and six mineral NDs (0–200 kg N ha^?1) at three sites (The Netherlands, Germany, Denmark). Differences between cultivars in PNUp_max and ND_opt were small; however, environments (defined as combination of site and year) substantially differed from each other: highest PNUp_max and lowest ND_opt occurred at environments supplying high amounts of N from soil resources, and vice versa. The level of maximum sugar yield (SY_max) was related neither to PNUp_max (200–270 kg N ha^?1) nor to ND_opt. However, N dose and plant N uptake required for 95% of maximum sugar yield was 50–80 kg N ha^?1 lower than for maximum sugar yield. To conclude, accepting a slight reduction in sugar yield might allow for a substantial decrease in the ND. Cultivar choice and yield level need not to be taken into account at present.