Hydrological and substrate requirements of the thick‐shelled river mussel Unio crassus (Philipsson 1788)          下载免费PDF全文

Katharina Stoeckl  Juergen Geist 《水产资源保护:海洋与淡水生态系统》2016,26(3):456-469

Synovial cyst of the fifth digit in a cat     

Katharina M. Hittmair  Irene Maedl  Martin Reifinger  Elisabeth Mayrhofer 《Journal of Feline Medicine and Surgery》2010,12(2):175-178

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Evaluating Emissions of Nitrous Oxide from Cropland Soils Under Different Rotations in Mato Grosso, Brazil: A Scenario Simulation Study     

Katharina H. E. MEURER  Eric BOENECKE  Uwe FRANKO 《土壤圈》2019,29(4):432-443

Expansion of cropland involves immense land use changes, and the resulting intensified management practices have a strong influence on the functioning of the underlying soil. For instance, increased application of nitrogen (N) fertilizer is known to enhance fluxes of nitrous oxide (N₂O) from the soil to the atmosphere. The emission factor (EF) proposed by the Intergovernmental Panel on Climate Change (IPCC) assumes a linear relationship between added N and N₂O-N fluxes, but it does not account for environmental factors, such as soil properties or climate. Due to the high spatial and temporal variability of N₂O-N fluxes, mechanistic models are preferable in terms of extrapolation to larger scales. In this study, we evaluated simulated N₂O-N fluxes from soils under agricultural use in the Brazilian state, Mato Grosso, using the CANDY (Carbon and Nitrogen Dynamics) model. A control tool was developed in order to enable the simulation of 1 650 scenarios covering different sites (soil + climate) and management regimes (crop rotation + amount of applied fertilizer + sowing and harvesting dates). Results suggested that the sites had a very strong influence on calculated emissions, which is not accounted for by static EF. Furthermore, most fertilizer-induced N₂O-N fluxes derived from the scenario simulations were best described by a non-linear function. For sounder budgeting on the federal and national scale, there is still a strong need for long-term observations of continuous crop rotations and spatial distribution of soil types and their specific characteristics. The presented results provide a valuable starting point for developing further scenario simulations and adapting experimental campaigns for N₂O emission study.  相似文献   

Biochar application to sandy soil: effects of different biochars and N fertilization on crop yields in a 3-year field experiment     

Anja Sänger  Katharina Reibe  Jan Mumme  Martin Kaupenjohann  Frank Ellmer  Christina-Luise Roß 《Archives of Agronomy and Soil Science》2017,63(2):213-229

During the past years, most biochar studies were carried out on tropical soils whereas perennial field experiments on temperate soils are rare. This study presents a 3-year field experiment regarding the effects of differently produced biochars (pyrolyzed wood, pyrolyzed maize silage, hydrothermal carbonized maize silage) in interaction with digestate incorporation and mineral N fertilizer application on soil C and N, crop yields of winter wheat, winter rye and maize and the quality of winter wheat. Soil C and plant available potassium were found to be significantly positive affected by pyrolyzed wood biochar whereas the latter only in combination with N fertilization. Crop yields of winter wheat, winter rye and maize were not affected by biochar and showed no interaction effects with N fertilizer supply. Wheat grain quality and nutrition contents were significantly affected by biochar application, for example, highest amounts of phosphorus, potassium and magnesium were determined in treatments amended with pyrolyzed maize silage biochar. Biochar induced an improved availability of plant nutrients, which apparently were not yield limiting in our case. These results limit the potentials of biochar for sustainable intensification in agriculture by increasing crop yields for the temperate zones. However, detection of other environmental benefits requires further investigations.  相似文献   

Carotenoids in diets for salmonids: I. Pigmentation of rainbow trout with the individual optical isomers of astaxanthin in comparison with canthaxanthin     

Per Foss  Trond Storebakken  Katharina Schiedt  Synnøve Liaaen-Jensen  Erland Austreng  Konrad Streiff 《Aquaculture (Amsterdam, Netherlands)》1984,41(3):213-226

Visual and chemical determinations revealed that the individual optical isomers of astaxanthin were more efficacious than canthaxanthin in pigmenting the flesh of rainbow trout (Salmo gairdneri, Richardson). The visual assessment of the astaxanthin pigmentation by means of a colour scale correlated well with the chemical determination. The same utilization was found for all three astaxanthin isomers, (3S, 3′S)-, (3R, 3′S)-, (3R, 3′R)-astaxanthin and a 1 : 2 : 1 mixture of the three isomers.No epimerization took place at the chiral centres of C-3 and C-3′ in astaxanthin. Astaxanthin and canthaxanthin were not interconverted. No metabolites were detected in the flesh.  相似文献   

Effect of Extending the Growing Period on Yield Formation of Sugar Beet          下载免费PDF全文

K. Schnepel  C. M. Hoffmann 《Journal of Agronomy and Crop Science》2016,202(6):530-541

Autumn sown sugar beets (winter beets) are expected to yield markedly higher than spring sown beets. This requires a continuous growth during an extended growing period. So far, bolting‐resistant sugar beet varieties are not available to test winter beets under field conditions in Central Europe. The objective of this study was therefore to analyse yield formation and sugar storage of sugar beet plants during an extended growing period to estimate whether sugar beet has the potential to generate the theoretically expected yield increase. From 2008 to 2012, pot experiments were carried out in the glasshouse with 11 sowing dates spread over the years with sequential harvests. The oldest plants were grown for 859 days (14 242 °Cd). Root fresh matter yield continuously increased till the latest harvest. In contrast, the sugar concentration reached an optimum value between 3400 and 5000 °Cd and then decreased with time. Despite longer growing periods, the number of cambium rings, which are regarded as essential for sugar storage, did not change. This points to an early and genetically fixed determination of the formation of cambium rings. Additionally, the rate of photosynthesis decreased concomitantly with the sugar concentration. In conclusion, there is some evidence that the sugar concentration of the storage root is limited by the sink capacity, which in turn controls the source activity by a feedback regulation of photosynthesis and leaf formation. The dry matter composition of the storage root changed towards lower sugar concentration and concurrent higher concentration of cell wall compounds (marc). The sugar yield still increased beyond a thermal time at which winter beets will probably be harvested in practice. Hence, the theoretical yield increase in autumn sown sugar beets can be realized, provided that the plants show sufficient winter hardiness and bolting resistance.  相似文献   

Assessing risks in relation to international trade with food and animals: a review of methods currently applied     

Stärk KD 《Berliner und Münchener tier?rztliche Wochenschrift》2004,117(5-6):182-187

Since approximately 10 years, risk assessments in the context of international trade with animals and food are being conducted. International standards provide guidelines for such assessments. However, the methods to be applied are only very broadly defined. A review of published or otherwise accessible examples demonstrated that most assessments in this field are qualitative in nature. When quantitative risk assessments are conducted, simulation modeling is often used. Further methodological development is required regarding the consideration of uncertainty, the use of expert knowledge and standardization of qualitative risk estimates. In order to maintain quality assurance in risk assessments, a wider use of peer-review is desirable, e.g. through publication of results in scientific journals.  相似文献   

Age-period-cohort analysis of the Bovine Spongiform Encephalopathy (BSE) epidemic in Switzerland     

Cohen-Sabas CH  Heim D  Zurbriggen A  Stärk KD 《Preventive veterinary medicine》2004,66(1-4):19-33

Cattle born after animal-feed control measures were implemented in 1990 have become BSE cases in Switzerland, indicating sub-optimal effectiveness of these measures. To evaluate these measures, the incidence of BSE cases in Switzerland recorded through clinical case reporting from January 1991 to June 2000 (categorized into age groups and birth cohorts of 6-month duration) was analyzed by Poisson log-linear regression using an age–period–cohort model. The incidence was maximum in the cattle cohort born from October 1989 to March 1990, and dropped to zero in the cohort born from April to September 1991. A second peak was observed in a cohort born from April to September 1994. The first drop of incidence is interpreted as a result of initial implementation of the feed ban in 1990. The second peak might be related to exposure of cattle to feed intended for pigs and poultry.  相似文献   

Development of a monitoring program for antibiotic resistance in bacteria from Swiss food-producing animals     

Ledergerber U  Regula G  Stephan R  Danuser J  Stärk KD 《Berliner und Münchener tier?rztliche Wochenschrift》2005,118(9-10):423-429

Resistant bacteria from food-producing animals may compromise the success of antibiotic treatment in animals and in humans. Therefore, the level of antibiotic resistance in bacteria from farm animals and its development over time needs to be monitored. In Switzerland, a monitoring program for antibiotic resistance is currently being developed. Pilot-monitoring programs were conducted in selected animal species in order to obtain current data on antibiotic resistance. The data on the prevalence of bacteria and antibiotic resistance in poultry were used to optimize the sampling plan. The influence of sampling more farms compared to sampling more animals per farm on the prevalence estimate for antibiotic resistance was analyzed by a Monte Carlo simulation model. Accounting for the costs for sample collection, transportation and laboratory analysis of the samples, the number of samples to be taken at the respective step in the production line was optimized. Optimization was defined as maximizing the precision of the prevalence estimate while minimizing the costs. The model will be expanded to other bacterial and animal species in the future.  相似文献   

Adverse effects of ketoconazole in dogs--a retrospective study     

Mayer UK  Glos K  Schmid M  Power HT  Bettenay SV  Mueller RS 《Veterinary dermatology》2008,19(4):199-208

Although ketoconazole has been used extensively in dogs for the treatment of various fungal infections, information about adverse effects is mainly anecdotal. Common adverse effects in humans include dose-dependant anorexia, nausea and vomiting, allergic rashes and pruritus. Drug-induced hepatitis is very rare, but potentially fatal. The aim of this study was to evaluate the type and frequency of adverse effects associated with ketoconazole therapy in dogs treated for skin diseases and any possible influence of dosage, duration of therapy, signalment or concurrent medication. The medical records of 632 dogs treated with ketoconazole (2.6–33.4 mg/kg) were reviewed. Adverse effects occurred in 14.6% (92 dogs) and included vomiting (7.1%), anorexia (4.9%), lethargy (1.9%), diarrhea (1.1%), pruritus (0.6%), erythema (0.3%) and other adverse effects (2.5%). Of the dogs with other adverse effects, four of 16 (25%) were ataxic and three of these received concurrent ivermectin. Adverse effects were significantly more often recorded in dogs concurrently treated with ciclosporin ( P =  0.034) or ivermectin ( P =  0.007). Increased liver enzyme levels were reported rarely, and icterus was not seen in any of the dogs. However, monitoring liver enzymes during therapy is recommended, although this might not necessarily prevent severe idiosyncratic hepatotoxicity.  相似文献