Bioavailability of N released from N-rich pyrogenic organic matter: An incubation study

In Mediterranean ecosystems, natural wildfires and prescribed burning play an important role. In order to obtain a better understanding of the impact of charcoal on the nitrogen (N) cycling in soil, ¹⁵N-enriched pyrogenic organic material (PyOM) obtained from “Lolium perenne” charred for 4 min at 350 °C was mixed with a typical Mediterranean agricultural soil and incubated for 72 days under controlled conditions. The main objectives were to analyze the availability of N from this material and to obtain more insight into the recalcitrance of PyOM in soils. Addition of artificially produced ¹⁵N-PyOM increased the biomass production and N retention. After 72 days of incubation time, 10% of the ¹⁵N added to the soil (¹⁵N_add) was incorporated into new grass biomass. Solid-state ¹⁵N NMR spectroscopy revealed that at least some of this N derived from the degradation of pyrrole-type structures. Increase of the amide-N intensity in the solid-state ¹⁵N NMR spectrum of the incubated soils indicated further that some ¹⁵N from the PyOM was also incorporated into new microbial biomass. Our results confirmed a relatively low recalcitrance of N-rich PyOM. Since during its degradation, N is only slowly transferred into a plant-available form, it may contribute to the observed improvement of soil fertility by avoiding fast N losses due to leaching and volatilization as a slow N-release fertilizer.     

Carbon flow into microbial and fungal biomass as a basis for the belowground food web of agroecosystems

The origin and quantity of plant inputs to soil are primary factors controlling the size and structure of the soil microbial community. The present study aimed to elucidate and quantify the carbon (C) flow from both root and shoot litter residues into soil organic, extractable, microbial and fungal C pools. Using the shift in C stable isotope values associated with replacing C3 by C4 plants we followed root- vs. shoot litter-derived C resources into different soil C pools. We established the following treatments: Corn Maize (CM), Fodder Maize (FM), Wheat + maize Litter (WL) and Wheat (W) as reference. The Corn Maize treatment provided root- as well as shoot litter-derived C (without corn cobs) whereas Fodder Maize (FM) provided only root-derived C (aboveground shoot material was removed). Maize shoot litter was applied on the Wheat + maize Litter (WL) plots to trace the incorporation of C4 litter C into soil microorganisms. Soil samples were taken three times per year (summer, autumn, winter) over two growing seasons. Maize-derived C signal was detectable after three to six months in the following pools: soil organic C (C_org), extractable organic C (EOC), microbial biomass (C_mic) and fungal biomass (ergosterol). In spite of the lower amounts of root- than of shoot litter-derived C inputs, similar amounts were incorporated into each of the C pools in the FM and WL treatments, indicating greater importance of the root- than shoot litter-derived resources for the soil microorganisms as a basis for the belowground food web. In the CM plots twice as much maize-derived C was incorporated into the pools. After two years, maize-derived C in the CM treatment contributed 14.1, 24.7, 46.6 and 76.2% to C_org, EOC, C_mic and ergosterol pools, respectively. Fungi incorporated maize-derived C to a greater extent than did total soil microbial biomass.     

ECHOLARYNGOGRAPHY IN CATS

Twenty-five cats with clinical signs of upper respiratory tract disease and five cats without upper respiratory signs underwent echolaryngography. Direct inspection of the larynx under general anesthesia was undertaken in all cats and used as the 'gold standard' for the diagnosis of laryngeal diseases. The aims were to: (a) establish which anatomic structures of the larynx are visible ultrasonographically in cats without upper respiratory tract disease, (b) establish which laryngeal abnormalities can be detected and accurately localised using ultrasonography and (c) evaluate in which conditions the technique may provide complementary information or an alternative method of investigation. The ultrasound investigation accurately indicated the presence and location of cysts and masses. Abnormal laryngeal movements were also detected, although it was difficult to confirm whether these were unilateral or bilateral. Vocal cord thickening was seen but the underlying cause could not be established with this technique.     

The suitability of ELISA for the detection of antibodies against Mycobacterium avium ssp. paratuberculosis in bulk milk samples from Rhineland-Palatinate

Paratuberculosis or Johne's Disease, caused by Mycobacterium avium subspecies paratuberculosis (MAP), is a notifiable disease in Germany which produces enormous economical losses in dairy farms. At present,there is no confirmed data about the actual number of infected livestock herds in Germany. A countrywide monitoring program to evaluate the prevalence in dairy herds would only be economically feasible on the basis of bulk milk testing. In this study, we evaluated two ELISA test kits (SVANOVIR Ptb-ELISA, IDEXX-M.pt. Milk test kit) for the detection of antibodies against MAP in bulk milk. First, the Paratuberculosis-status of the herd derived from the history of the farm was used as a gold standard. Paratuberculosis-negative farms were tested negative with each test, but paratuberculosis-positive or Paratuberculosis-serologically-positive farms were detected only in one case (Svanovir) or three cases (IDEXX), respectively. Even if inconclusive results are counted as positive, 82.9 % (Svanovir) or 80 % (IDEXX) of the paratuberculosis-positive or serologically paratuberculosis positive farms were not detected. Nevertheless, a re-validation of both ELISAs by means of ROC and TG-ROC analyses was attempted by searching for ideal cut-offs, optimised for bulk milk. If a high specificity was selected, no acceptable sensitivity could be reached.The best results were obtained using a sensitivity of 32.3 % at a specificity of 100 % (Svanovir). With a small change of the cut-off value, the sensitivity increased to still 57 %, but this reduced the specificity to 67 %. Similar results were obtained with the IDEXX-ELISA. We then evaluated the Svanovir-ELISA for the detection of bulk milk samples on the basis of the current paratuberculosis prevalence within 69 dairy herds from Rhineland-Palatinate using individual milk samples.When the bulk milk samples were tested in two different laboratories using the same ELISA, considerable differences in the results became evident. Nearly all samples were tested with a higher relative test result in one laboratory, which often led to differences in the classification of the prevalence levels.The estimated within-herd seroprevalences ranged between 0 % and 37 %.There was little agreement between the historical paratuberculosis herd status and the within-herd prevalence in milk serum, as reflected in a kappa-index of 0.146.To determine the sensitivity and specificity of the bulk milk ELISA by ROC and TG-ROC analysis, 116 bulk milk samples were used that had been obtained from the 69 dairy herds participating in the study. The optimal ratio of sensitivity (81 %) and specificity (77 %) relative to a "gold standard" was obtained when the cut-off was set at the 10 % level. These values for sensitivity and specificity were better than those obtained in an evaluation of the same ELISA in which the historical Paratuberculosis herd-status was used as a "gold standard." The results of this study question the suitability of the available ELISAs for bulk milk testing.Taking into account that the Svanovir-ELISA for individual milk samples has a sensitivity of 60 96% relative to the blood serum variant of the test, and that the latter has also a limited sensitivity due to the pathogenesis of paratuberculosis, the available test systems examined in this Study do not seem to be suitable for herd diagnosis by using bulk milk samples.     

Osmotic stress and silicon act additively in enhancing pathogen resistance in barley against barley powdery mildew

Osmotic stress as well as silicon (Si) improve the resistance of barley (Hordeum vulgare cv. Ingrid) against barley powdery mildew (Blumeria graminis f. sp. hordei Speer). Nothing is known about interactions, particularly whether Si is necessary for pathogen resistance induced by osmotic stress. In this paper, we show that Si nutrition was not necessary for osmotic‐stress‐induced pathogen resistance. Si‐mediated resistance could, however, be enhanced by osmotic stress and vice versa. Even at maximum Si‐mediated resistance, further enhancement of pathogen resistance by osmotic stress was possible. The fungus was controlled by the formation of effective papillae in both treatments. The combined effect of Si and osmotic stress was as strong as the calculated addition of the Si and the osmotic‐stress effect. Our data clearly show that the effect of osmotic stress and Si is not competitive but additive. A synergistic action of both treatments cannot be supported by our data. It is assumed that the basal pathogen resistance of barley is enhanced by Si due to strengthening of papillae in addition to the increased formation of effective papillae induced by osmotic stress. Therefore, the addition of Si increases pathogen resistance equally at all investigated NaCl concentrations. A function of Si in pathogen defense exceeding the strengthening of papillae is not supported by our data.     

Morphological, immunohistochemical, and ultrastructural findings in an embryonal rhabdomyosarcoma of a newborn thoroughbred foal

This study reports the rare case of a rhabdomyosarcoma in the shoulder of a newborn Thoroughbred foal. Histomorphologic, immunohistochemical, and ultrastructural investigations revealed an embryonal rhabdomyosarcoma with various differences: small round undifferentiated cells, rhabdomyoblast-like neoplastic cells, and spindle-shaped cells. Desmin expression appears in 30% of small round cells and in as many as 90% of spindle-shaped cells. Vimentin co-expression occurs in 90% of small round and spindle-shaped neoplastic cells but only in few (30%) rhabdomyoblast-like cells. Myoglobin was detected in 50% of the rhabdomyoblast-like cells and in 30% of spindle-shaped cells but not in small round neoplastic cells. This is the first time that rhabdomyosarcoma markers Myf-4 and Myo D1 were found in horses. Myf-4 and Myo D1 were expressed in about half of the neoplastic cells in immediately fixated specimens. Ultrastructural sarcoma-like packets and formations of primitive Z-bands, as well as a discontinuous basal lamina, were found and served to confirm our diagnosis.

Introduction

Malignant neoplasia of striated muscles in domestic animals represents uncommon findings.[1] Only single cases of rhabdomyosarcoma in horses of varying ages (2-19 years) and races (Quarter horses, Appaloosas, Thoroughbreds, ponies) were described. [2, 3, 4, 5, 6 and 7]In human medicine, histopathologically different partly overlapping types of rhabdomyosarcoma are distinguished, reflecting stages of differentiation and the morphology of the neoplastic cells[8 and 9]: (1) embryonal rhabdomyosarcoma (subtypes: spindle cell, small cell) and its botryoid variant; (2) alveolar (synonymous with juvenile) rhabdomyosarcoma; and (3) pleomorphic (synonymous with adult) rhabdomyosarcoma.In veterinary pathology, rhabdomyoma, rhabdomyosarcoma, and “embryonal rhabdomyosarcoma of the urinary bladder in dogs” are actually distinguished histopathologically.[10] But in older references the nomenclature of human medicine is used.In horses, alveolar rhabdomyosarcoma occur in the extremities.[2 and 5] Botryoid rhabdomyosarcomas were described in the equine uterus [4] and the urinary bladder. [7] Pleomorphic rhabdomyosarcomas are found in the tongue [6] and inside the thorax. [3]Differential diagnoses include fibrosarcoma, melanoma, anaplastic lymphosarcoma, and anaplastic carcinoma. Immunohistochemical[10, 11 and 12] and ultrastructural [13 and 14] investigations are helpful in confirming a diagnosis of rhabdomyosarcoma.Myo D1, Myf-3, and Myf-4 belong to a group of myogenic regulatory proteins whose expression determines commitment and differentiation of primitive mesenchymal cells into skeletal muscle.[15] Myf-3 protein, the human homologue of the murine Myo D1 gene product, is a factor capable of myogenic determination, whereas Myf-4, the human homologue of myogenin, is required downstream as a differentiating factor. [15]This paper reports morphologic, immunohistochemical, and ultrastructural findings of an unusual case of embryonal rhabdomyosarcoma in the right shoulder of a newborn foal.

Case history

A newborn Thoroughbred foal showed a swelling in the right shoulder. This thickening was growing fast and at the age of 3 months a carneous mass of 5 kg was removed surgically by the local veterinarian. A distal dehiscence of the suture appeared and the swelling recurred within the following 3 months.

Clinical findings

When the foal was presented to the veterinary clinic at the age of 6 months, it showed a good general condition and no evidence of lameness. The right shoulder laterally showed a thick firm swelling of 20 cm. (Fig 1). At the caudodistal edge, a 10 cm deep fistula was found and sonographic examination showed multiple cysts within the tissue. Cytologic examination of the cyst fluid revealed numerous neutrophils and some adipocytes. Additional clinical findings revealed mild blood leukocytosis.     

Soil indicator systems ‐ the basis for soil conservation decisions to control soil erosion and soil compaction

The efficiency and acceptance for erosion and compaction control management is not high and therefore not a guarantee for sustainable land use and soil functionality. The best method for increasing acceptance is a regional soil indicator system combined with an environmental indicator system (McRae et al. 2000). Like the concept of “critical load inputs”; for chemical pollutants, this system would make it possible to quantify the soil state and soil condition for decisions concerning the soil carrying or load capacity. The next step is the assessment of the land use pressure on soil in terms of the soil load capacity and the driving forces for land use. These results may determine the response level required: In a balanced situation, Best Management Practices may help ensure sustainability is maintained, slightly disproportional results suggest additional special agricultural management techniques may be needed, while significant differences may indicate the need for additional land use adjustments or changes in technical management. The indicator system is ideal for application in north‐eastern Germany for all moraine areas and the areas at risk to water and wind erosion and soil compaction.     

Efficient application of in vitro anther culture for different European winter wheat (Triticum aestivum L.) breeding programmes

The efficiency of our anther culture protocol was tested with high‐ and low‐responding genotypes, ‘Svilena’ and ‘Berengar’, and 93 F₁ winter wheat crosses in 2010 and 2011. Based on data for these genotypes, the effect of genotype influenced the number of embryo‐like structures, regenerated plantlets and green plantlets, while the number of albino plantlets was affected by genotype, year and environmental factors. Although genotype also influenced the production of green plantlets from breeding crosses, with green plantlets per 100 anthers ranging from 0.04 to 28.67, the average regeneration rate over all crosses was 5.3 green plantlets/100 anthers, which resulted in a total of 11 416 well‐rooted green plantlets. The survival rate of green plantlets following acclimatization was 97.21% in 2010 and 96.34% in 2011. In this study, the phenomenon of albinism and genotype dependency did not hinder the production of more than five thousand green plantlets each year. In our experiments, anther culture proved to be an efficient method in winter wheat breeding programmes with lower costs than alternative technologies.     

华北平原不同种植模式的水氮利用

2007～2009年在河北省中国农业大学吴桥实验站进行两年的田间定位试验,试验设3个种植模式,分别为冬小麦-夏玉米一年两熟常规模式、春玉米一熟优化管理模式和冬小麦-夏玉米-春玉米两年三熟优化管理模式,探讨在华北地区通过调整种植模式的途径实现农业节水减氮的潜力。结果表明,冬小麦-夏玉米一年两熟常规模式（对照）具有显著产量优势,但水分利用率和氮肥利用率均较低,水氮浪费较为严重,不利于华北平原地区农业的可持续发展;与对照相比,春玉米一熟模式水氮消耗量最小,水氮利用率均显著提高,具有良好的环境效应,但其产量降低较多,不适宜在生产中单独推广;两年三熟模式两年总灌溉用水量降低了63%,氮肥用量降低了75%,产量降低了21%,节水减氮效果明显,水氮利用效率显著提高,该模式进一步完善后可适当推广。