Landwirtschaftliche Fachschule Tulln

Vital mitochondrial DNA (mtDNA) populations exist in cells and may consist of heteroplasmic mixtures of mtDNA types. The evolution of these heteroplasmic populations through development, ageing, and generations is central to genetic diseases, but is poorly understood in mammals. Here we dissect these population dynamics using a dataset of unprecedented size and temporal span, comprising 1947 single-cell oocyte and 899 somatic measurements of heteroplasmy change throughout lifetimes and generations in two genetically distinct mouse models. We provide a novel and detailed quantitative characterisation of the linear increase in heteroplasmy variance throughout mammalian life courses in oocytes and pups. We find that differences in mean heteroplasmy are induced between generations, and the heteroplasmy of germline and somatic precursors diverge early in development, with a haplotype-specific direction of segregation. We develop stochastic theory predicting the implications of these dynamics for ageing and disease manifestation and discuss its application to human mtDNA dynamics.

In this paper we investigate whether inflation causes the time-varying mean-reverting level in the Balduzzi et al. (Review of Economics and Statistics, Vol. 80, No. 1 (1998), pp. 62–72) short rate model. We find a time-varying mean-reverting level for the UK nominal short rate, but the real short rate mean reverts to a constant. This suggests a monetary source for the time-varying mean-reverting level in nominal short rate models. The time-varying mean factor is closely related to market expectations about future inflation. This suggests that expected future inflation determines the mean-reverting level of the nominal short rate.

Only little attention has been paid to hetero polycyclic aromatic hydrocarbons (N-, Sor O-substituted PAHs), a group of substances which is found together with PAHs. Hetero PAHs typically show a higher water solubility and a higher bioavailability than the structurally corresponding PAHs. The focus was to study the toxicity of fluorene and the similar hetero PAHs as carbazole, dibenzothiophene and dibenzofuran. Bioassays were carried out with Heterocypris incongruens (Ostracod Toxkit F) and Vibrio fischeri (Lumistox). H. incongruens show the highest sensitivity to carbazole, V. fischeri are most sensitive to dibenzofuran from the studied substances. In the presence of natural sediment toxicity was dramatically reduced. This effect can be deduced to the presence of organic matter (e.g. humic acids) in solid and dissolved form. A aqueous mix of all tested PAHs showed different toxicity results compared to the tested single substances. An explanation for this result is presented. No additive toxicity effects could be observed. from 13th Scientific Symposium of the Austrian Pharmacological Society (APHAR). Joint Meeting with the Austrian Society of Toxicology (ASTOX) and the Hungarian Society for Experimental and Clinical Pharmacology (MFT) Vienna, Austria. 22–24 November 2007

B-trichothecenes are one of the most common contaminants of cereals in Europe. Therefore, the use of fast and accurate methods is necessary to measure contamination levels and observe regulatory limits.At the moment, mostly gas chromatographic (GC) methods are used but HPLC-UV methods are also employed. Clean-up is commonly done either with immunoaffinity or Mycosep® columns.In the Christian Doppler Laboratory for Mycotoxin Research we have established an alternative HPLC method with post column derivatisation (PCD) as an alternative to existing chromatographic methods. This PCD-HPLC-FLD method uses a Mycosep® clean-up and allows the simultaneous detection and quantification of deoxynivalenol, nivalenol, fusarenon X, 3-acetyldeoxynivalenol and 15-acetyldeoxynivalenol. A validation with wheat gave for deoxynivalenol a limit of quantification ten times below the drafted European Union guideline level (500 µg.kg(-1)) and a limit of detection of 8 µg.kg(-1). The relative standard derivation for DON was 10% (n=30). The obtained mean recovery rate for DON was 90% in a range from 50 to 1000 µg.kg(-1).