Adding dissolved organic carbon to simulate freeze‐thaw related N2O emissions from soil     

Ulrike Sehy  Jens Dyckmans  Reiner Ruser  Jean Charles Munch 《植物养料与土壤学杂志》2004,167(4):471-478

It has been assumed that high winter N₂O emissions from soils are the result of increased amounts of microbially available organic C liberated during freezing and metabolized during subsequent thawing. In a laboratory experiment, we attempted to simulate freeze‐thaw events by adding dissolved organic C (DOC) to sieved soil of high water content (95% water‐filled pore space). In a full factorial design, CO₂ and N₂O emissions of a) soil samples provided with DOC extracted from frozen soil and b) soil samples frozen for 46 days and thawed were compared. Additionally, NO , DOC and microbial ATP contents of all treatments were repeatedly analyzed during the experiment. The addition of DOC to unfrozen soil (–F+C) resulted in a substantial (22‐fold) increase in N₂O emissions as compared to the control (–F–C). However, following thawing, the increase in N₂O emissions was much larger (828‐fold in +F–C and 1243‐fold in +F+C). Freezing, but not the addition of DOC led to increased CO₂ emissions. Neither treatment affected microbial adenylate content. By adding ¹⁵N‐labeled nitrate to the soil samples, the main process leading to elevated N₂O flux rates after both DOC addition and freeze‐thaw treatment was identified as denitrification. We conclude that the availability of C substrate plays an important role for freeze‐thaw‐related N₂O emissions. However, the fact that the simulated treatment and the freeze‐thaw treatment yielded significantly different amounts of N₂O suggests that both quantity and quality of available C differed between the treatments. The localization of the liberated substrate, i.e., the availability in situ, seems to be of major importance for the amount of N₂O produced.  相似文献   

Safety of percutaneous ultrasound-guided fine-needle aspiration of adrenal lesions in dogs: Perception of the procedure by radiologists and presentation of 50 cases     

Pascaline Pey  Alessia Diana  Federica Rossi  Jeremy Mortier  Ulrike Kafka  Stefanie Veraa  Anna Groth  Megan MacLellan  Chiara Marin  Federico Fracassi 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2020,34(2):626-635

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Assisted reproduction for felid species conservation—Sperm competences at risk     

Karin Müller  Susanne Eder  Ulrike Jakop  Jürgen Schiller  Peter Müller  Mohammad Bashawat 《Reproduction in domestic animals》2020,55(Z2):55-60

Cryobanking of gametes in combination with artificial insemination is an essential option to support conservation programmes for endangered and threatened species. About two-thirds of the felid species are classified as ‘near threatened’, ‘vulnerable’ or ‘endangered’ ( www.cites.org ), and mostly, epididymal sperm are collected from euthanized or castrated male felids and cryopreserved. However, epididymal compared with ejaculated and cryopreserved compared with fresh sperm have a limited potential to fertilize if vaginal non-surgical insemination is applied in feline species. Missing or highly diluted seminal fluid in epididymal and cryopreserved sperm, as well as a potential interference of extender ingredients with the natural interactive properties of sperm in the female genital tract is discussed as potential drawback which hampers a proper sperm transit and fertilization besides the limited longevity of cryopreserved feline sperm. Individual components in seminal fluid as well as cryoextenders may adversely alter sperm properties and have a different impact on fertility and preservation success. The identification and investigation of beneficial as well as detrimental components is a precondition to deduce options for improving the process of cryopreservation in felids, particularly, if only epididymal sperm are available.  相似文献   

Zur systematischen Stellung und Bodenentwicklung des Tschernosems des Oberrheintales und der Smonica in Rheinhessen     

Ulrike Leßmann-Schoch  Thomas Schbel  Siegfried Stephan 《植物养料与土壤学杂志》1988,151(1):9-14

Systematical status and soil development of the Tschernosem des Oberrheintales and the Smonica of Rheinhessen (W-Germany) The Tschernosem des Oberrheintales and the Smonica of Rheinhessen are discussed respectively to their position in the soil system of the Federal Republik of Germany, as well as in the FAO/Unesco classification and USDA Soil Taxonomy. Both soils are subrelictic, and the recent behavior of the Smonica does not allow it to be placed among the Vertisols. The history of these soils is described as investigated by field work, palynology and micromorphology. Some connecting profiles between the exposed ones have been outlined.  相似文献   

Non-enhancing confirmed oligodendroglioma in three dogs     

Motta L  Altay UM  Kelly D  Skerritt GC 《The Journal of small animal practice》2011,52(4):227-227

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Quantitative resistance level (MIC) of Escherichia coli isolated from calves and pigs suffering from enteritis: national resistance monitoring by the BVL     

Schröer U  Kaspar H  Wallmann J 《Berliner und Münchener tier?rztliche Wochenschrift》2007,120(9-10):431-441

National Resistance Monitoring of the Federal Office of Consumer Protection and Food Safety (BVL), which was put into service in 2001, has made it possible to implement a valid and representative database on the basis of which the resistance situation, development and spread in animal pathogens can be evaluated. Escherichia coil (E. coli) strains originating from calves and pigs suffering from enteritis were first included in the investigations in the 2004/2005 study. A total of 258 bovine and 492 porcine E. coli strains were tested using the broth microdilution method to determine the in vitro susceptibility (minimum inhibitory concentration) to 23 (fattening pigs) and 28 (calves, piglets, weaners) different antimicrobial substances. Considerable prevalences of resistance were found for some antimicrobials. The strains originating from both animal species displayed high prevalences of resistance for tetracycline, trimethoprim, trimethoprim/sulfamethoxazole, doxycycline and ampicillin. Reduced susceptibility was detected particularly in the E. coli strains from calves. The data reveal that the resistance level of E. coli strains isolated from cases of enteric disease in calves and pigs is altogether higher than has so far been reported in pathogens causing different diseases and in other food-producing animal species. Based on the results presented, it is possible to assess the current resistance situation for E. coli strains in calves and pigs in Germany. This in turn helps to deduce the necessary management measures that can be taken in order to minimise resistance to antibiotics. Furthermore, the data help to decide on adequate therapy of E. coli infections of the intestinal tract in calves and pigs and encourage the responsible use of antibiotics in the interests of animal health and consumer protection.  相似文献   

Quantitative resistance level (MIC) of bacterial pathogens (Escherichia coli, Pasteurella multocida, Pseudomonas aeruginosa, Salmonella sp., Staphylococcus aureus) isolated from chickens and turkeys: national resistance monitoring by the BVL 2004/2005     

Wallmann J  Schröer U  Kaspar H 《Berliner und Münchener tier?rztliche Wochenschrift》2007,120(9-10):452-463

In the study 2004/2005, the current quantitative resistance level of Escherichia coli, Pasteurella multocida, Pseudomonas aeruginosa, Salmonella sp. and Staphylococcus aureus from chickens and turkeys was determined for the first time within the framework of the National Resistance Monitoring of the Federal Office of Consumer Protection and Food Safety (BVL).The objective was to implement a valid database on the basis of which the development and spread of resistance can be evaluated and monitored. During the investigation period from January 2004 to February 2005,927 strains were collected and 857 (92%) bacteria strains which corresponded to the specifications of the study protocol were tested with the broth microdilution method to determine the in vitro susceptibility (minimum inhibitory concentration) to 22 to 28 antimicrobial agents or antibiotic combinations. The results document a prevalence of resistance that exceeds that of bacterial pathogens of other animal species, especially in the case of tetracycline. Apart for S. aureus, clinical resistance to fluoroquinolones can still be considered low in poultry pathogens (E. coli approx. 2%). By applying the MICG of 4 mg/L for enrofloxacin, a susceptibility of approximately 78 % was calculated for S. aureus. A comparison of the prevalence of resistance between chickens and turkeys, showed that a slightly higher prevalence of resistance can be expected in turkeys. Differences between the susceptibility data of chicks and adult animals could only be found in turkeys. In the case of E. coli, the prevalence of resistance of strains isolated from adult turkeys was up to 10% higher than those isolated from chicks for the corresponding antimicrobial agents. It must be pointed out that the number of E. coli strains from adult turkeys was much higher (n = 194) than the number from turkey chicks (n = 21). The results indicate clearly that in a resistance monitoring system it is necessary to categorise poultry by animal species (chicken, turkey) as well as by production stage and type (broiler, laying hen), so that the epidemiology of resistance can be correctly represented and evaluated. This information is the basis for the development of long-term management options for minimizing antibiotic resistance. Furthermore, the knowledge of prevailing resistance levels in Germany is a valuable tool for veterinary practitioners when determining an empirical therapy.The data collected by the BVL make an important contribution to the optimisation of the safety of food from animals, and thus to improving consumer protection.  相似文献   

Sandwich immunoassays for the determination of peanut and hazelnut traces in foods     

Kiening M  Niessner R  Drs E  Baumgartner S  Krska R  Bremer M  Tomkies V  Reece P  Danks C  Immer U  Weller MG 《Journal of agricultural and food chemistry》2005,53(9):3321-3327

People suffering from food allergies are dependent on accurate food labeling, as an avoidance diet is the only effective countermeasure. Even a small amount of allergenic protein can trigger severe reactions in highly sensitized patients. Therefore, sensitive and reliable tests are needed to detect potential cross-contamination. In this paper two fast sandwich immunoassays are described for the determination of peanut (Arachis hypogaea) and hazelnut (Corylus avellana) traces in complex food matrices. Mouse monoclonal antibodies were used as capture antibodies, and labeled rabbit polyclonal antibodies were used as detection antibodies in both assays. The assay time was 30 min in total, and cross-reactivities against a variety of fruits and seeds were found to be in the low 10(-4)% (ppm) level or in some cases not detectable. The recoveries in all tested food matrices ranged from 86 to 127%, and the limits of detection were in the range of 0.2-1.2 mg/kg (ppm) in food for both peanut and hazelnut, respectively.  相似文献   

Stickstoffentzug durch Pflanzen als Bewertungskriterium für den Grad der Torfmineralisation     

Horst Käding  Jürgen Augustin  Ulrike Münchmeyer  Wolfgang Leipnitz 《Archives of Agronomy and Soil Science》2013,59(6):557-572

Aus vorliegenden Versuchsergebnissen werden Aussagen zum N‐Kreislauf auf Niedermoorgrünland bei gestaffelter Stickstoffdüngung gemacht. N‐Düngung und Torfmineralisation sind entscheidende Inputgrößen. Die Outputseite wird wesentlich durch Stickstoffentzüge der Pflanzen bestimmt. Die N‐Zufuhr durch Knöllchenbakterien, freilebende N‐bindende Bakterien und Niederschläge ist anteilmäßig gering. Auch sind die N‐Verluste auf Niedermoorstandorten durch Auswaschung und gasförmige Emissionen niedrig. Die Rohproteinerträge auf nicht mit Stickstoff gedüngtem, aber ausreichend mit Makronährstoffen versorgtem Niedermoor sind Anhaltsgrößen für die Mineralisationsrate des Standortes. Nach Stickstoffdüngung kann, bei einer Ausnutzungsrate von 48%, ebenfalls auf die Netto‐N‐Mineralisationsrate geschlossen werden.  相似文献   

Soil organic carbon in the rocky desert of northern Negev (Israel)     

Ulrike Hoffmann  Aaron Yair  Harald Hikel  Nikolaus J. Kuhn 《Journal of Soils and Sediments》2012,12(6):811-825

Purpose

So far, the soil organic carbon (SOC) literature is dominated by studies in the humid environments with huge stocks of vulnerable carbon. Limited attention has been given to dryland ecosystems despite being often considered to be highly sensitive to environmental change. Thus, there is insufficient research about the spatial patterns of SOC stocks and the interaction between soil depth, ecohydrology, geomorphic processes, and SOC stocks. This study aimed at identifying the relationship between surface characteristics, vegetation coverage, SOC, and SOC stocks in the arid northern Negev in Israel.

Materials and methods

The study site Sede Boker is ideally suited because of well-researched but variable ecohydrology. For this purpose, we sampled five slope sections with different ecohydrologic characteristics (e.g., soil and vegetation) and calculate SOC stocks. To identify controlling factors of SOC stocks on rocky desert slopes, we compared soil properties, vegetation coverage, SOC concentration, and stocks between the five ecohydrologic units.

Results and discussion

The results show that in Sede Boker, rocky desert slopes represent a significant SOC pool with a mean SOC stock of 0.58?kg?C?m^?2 averaged over the entire study area. The spatial variability of the soil coverage represents a strong control on SOC stocks, which varies between zero in uncovered areas and 1.54?kg?C?m^?2 on average in the soil-covered areas. Aspect-driven changes of solar radiation and thus of water availability are the dominant control of vegetation coverage and SOC stock in the study area.

Conclusions

The data indicate that dryland soils contain a significant amount of SOC. The SOC varies between the ecohydrologic units, which reflect (1) aspect-driven differences, (2) microscale topography, (3) soil formation, and (4) vegetation coverage, which are of greatest importance for estimating SOC stocks in drylands.  相似文献