Denitrification- and Nitrate Leaching-Losses in an Intensively Cropped Watershed

In continuation of former measurements about gaseous denitrification losses, these losses together with those by nitrate leaching were measured by different methods in a field cropped during two years by wheat. Furthermore, N-uptake by the plants of fertilizer- and soil-N as well as N-im-mobilization in soils during and after the cropping periods was determined by application of highly enriched¹⁵N-labeled fertilizer. Denitrification losses determined by the N₂O release from C₂H₂–treated undisturbed soil cores agreed reasonably well with losses obtained by ¹⁵N-balance measurements. They both amounted during the cropping periods 12–15 and 6–20 kg N ha^?1, respectively. Gaseous N-losses increased mainly during wet periods when the field was barren. Denitrifying enzyme activities and soil respiration (CO₂-release) was measured throughout one year. Leaching losses of NO₃ from soil-and fertilizer-N occurred only during fall until spring. Leached NO₃^? originated mostly from mineralized soil-N and very little from previously immobilized fertilizer-N.     

Red fluorescence in reef fish: A novel signalling mechanism?

Background  

At depths below 10 m, reefs are dominated by blue-green light because seawater selectively absorbs the longer, 'red' wavelengths beyond 600 nm from the downwelling sunlight. Consequently, the visual pigments of many reef fish are matched to shorter wavelengths, which are transmitted better by water. Combining the typically poor long-wavelength sensitivity of fish eyes with the presumed lack of ambient red light, red light is currently considered irrelevant for reef fish. However, previous studies ignore the fact that several marine organisms, including deep sea fish, produce their own red luminescence and are capable of seeing it.     

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

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.     

Stickstoffentzug durch Pflanzen als Bewertungskriterium für den Grad der Torfmineralisation

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.     

Protecting the Commons: the use of Subtidal Ecosystem Engineers in Marine Management

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Investigation of serological prevalence and risk factors of paratuberculosis in dairy farms in the state of Mecklenburg-Westpommerania, Germany

A total of 2,997 serum samples were randomly taken at 59 pre-selected dairy farms covering all districts with an average of 334 animals kept per farm. Samples were analysed for antibodies against Mycobacterium avium subspecies paratuberculosis (M.a.p.) using Svanovir-ELISA. Risk factors on farm characteristics and animal health were recorded at all participating farms by use of a questionnaire. Fifty out of 59 farms (84.7%) showed at least one reactor. The average within herd prevalence was 12.2%. In the univariate analysis of risk factors no significant differences towards farm prevalences were found. Results are discussed with special emphasis on the need for a common national strategy to control the disease in Germany.     

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

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.     

Cytotoxic ellagitannins from Reaumuria vermiculata

Three ellagitannins and one disulfated flavonol were isolated from the aerial parts of Reaumuria vermiculata L. Besides that, 16 known compounds were characterized as well. The structures of all compounds were elucidated on the basis of spectroscopic data including 1D and 2D NMR and ESI HR-FTMS. The in vivo antioxidant activity using the oxygen radical absorbance capacity (ORAC) method, of the extract, its column fractions and two of the isolated ellagitannins was accomplished. In addition, a possible cytotoxicity of the extract and two of the new ellagitannins on HaCaT human keratinocytes and the activity of both compounds against the prostate cancer cell line (PC-3) were also assessed, whereby a potent cytotoxicity with IC(50) less than 1μg/ml was determined for both compounds. Besides, the extract exhibited a potential cytotoxic effect against four different solid tumor cell lines, namely liver (Huh-7), colorectal (HCT-116), breast (MCF-7) and prostate (PC-3). The IC(50)s were found to be substantially low (ranged from 1.3±0.15 to 2.4±0.22μg/ml) with relatively low resistance possibility reaching to 0% in the case of Huh-7 cell.