Immobilization of oligonucleotides on crosslinked poly(vinyl alcohol) for application in DNA chips.

In biotechnological applications there is an enormeous growth in the development of new miniaturized devices to reduce timescales, cost and amounts of reagents and starting materials. DNA chips represent miniaturized analytical tools that allow the simultaneous detection of different targets for high throughput screening. They consist of a small size support on which DNA probes are in-situ synthezised or immobilized.

Chilling and cultivar type affect the diversity of bacterial endophytes colonizing sweet pepper (Capsicum anuum L.).

A climate chamber experiment was conducted to assay the effect of low temperatures (chilling) on the diversity of bacteria colonizing the endospheres of two thermophilic sweet pepper (Capsicum anuum L.) cultivars, Milder Spiral and Ziegenhorn Bello. Structural diversity was analyzed by 16S rRNA-based terminal restriction fragment length polymorphism (T-RFLP) analysis and by the generation of 16S rRNA gene libraries to determine dominant community members in T-RFLP profiles.

Identification of adaptation-specific differences in mRNA expression of sessile and pedunculate oak based on osmotic-stress-induced genes.

Quercus petraea (Matt.) Liebl. and Q.

Investigation of food contamination since the Chernobyl fallout in Austria.

In a large-scale investigation the decrease of the activity concentration of 137Cs in foodstuffs after the widespread Chernobyl fallout was determined. At different times after the deposition in 1986 more than 1000 samples of various foodstuffs in Austria were taken and investigated with regard to their activity concentration. The investigation showed that in the first year after deposition, the activity concentration decreased to about 6-10% (milk, fruit), and 3-6%, respectively (grain, potatoes, vegetables) of the values in the fallout maximum.

Characterisation of selected cadmium--zinc--telluride detectors.

The performance of new detection technologies like the ambient temperature cadmium--zinc--telluride (CdZnTe) detectors is of interest for search and identification of radioactive material in a range of applications. Various types of CdZnTe detectors that are currently available on the market as well as some specially designed ones were tested and characterised. The examination included peak shape, energy-resolution, energy-range and also the usability in hand-held applications.

Sustainability of radiologically contaminated territories.

Decisions on appropriate countermeasures in the case of a contamination of large areas due to fallout from a weapon's detonations or a serious reactor or reprocessing plant accident depend on fallout level and the time period required for the exposure levels to fall below a given intervention limit. This is particularly relevant for countermeasures with high costs and substantial consequences to the population involved, such as relocation or soil perturbation. Natural processes which result in a decrease in activity concentrations in foodstuffs and external exposure with time, are least detrimental to the soil among all countermeasures proposed for rehabilitation of contaminated areas.

The use of the Monte Carlo simulation technique for the design of an H*(10) dosemeter based on TLD-100.

The thermoluminescence (TL) detector material LiF:Mg,Ti (TLD-100) and appropriate filter materials were combined in order to design a passive dosemeter measuring the operational quantity ambient dose equivalent, H*(10), for monitoring low-dose external photon radiation fields. Using the Monte Carlo simulation technique, optimisations of energy dependent conversion coefficients from air kerma free-in-air compared to ICRU and ISO proposed values. h*K(10), were performed by varying dosemeter detector positioning.

A ultra low level laboratory for nuclear test ban measurements.

The radionuclide laboratory at the Austrian Research Centers Seibersdorf (ATL03) was installed to support the international monitoring system for verification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT and Text of the establishment of a Preparatory Commission for the Comprehensive Test-Ban-Treaty Organization, 1996). Therefore, the background of a high-purity germanium detection system has been reduced by developing a high sophisticated active and passive detector shielding. The entire system is encapsulated in an iron-castle and placed into a fall-out shelter.

Langerhans cells and immature dendritic cells as model systems for screening of skin sensitizers.

Langerhans cells are the most potent antigen-presenting cells in the skin and play a critical role in the induction of contact allergy. Research on the phenotypical and functional changes of LCs occurring after application of skin sensitizers indicated their use as an in vitro model for the screening of chemicals. In the present investigations, LCs from human skin explants served as the test system.

Transfer of iodine from soil to cereal grains in agricultural areas of Austria.

The concentrations of iodine in cereal grains cultivated at 38 locations in Austria from cereal-producing sites in agricultural areas and soil-to-grain transfer factors (TF) were determined. The concentrations of iodine in cereal grains, which were analyzed by radiochemical neutron activation analysis ranged from 0.002 to 0.

The expression of surface markers on dendritic cells as indicators for the sensitizing potential of chemicals.

Novel approaches to testing of skin sensitizing chemicals have made use of immature dendritic cells (DCs) cultured from different hematopoietic progenitors. These cells resemble Langerhans cells (LCs), which are the most potent antigen presenting cells in the skin. Former research has focused on the phenotypic and functional changes of LCs after application of skin sensitizers.

Occupational exposure to static, ELF, VF and VLF magnetic fields and immune parameters.

Despite the important role of the immune system in defending the body against infections and cancer, very few investigations have been undertaken to study possible effects of electromagnetic fields on human immunity. The aim of the present study was to examine the effect of occupational exposure on hospital personnel operating magnetic resonance tomographs and on industrial workers at induction heaters. In both categories of workplaces, magnetic flux densities exceeding Austrian exposure standards have been registered.

Genetically modified organisms in food-screening and specific detection by polymerase chain reaction.

PCR methods for the detection of genetically modified organisms (GMOs) were developed that can be used for screening purposes and for specific detection of glyphosate-tolerant soybean and insect-resistant maize in food. Primers were designed to amplify parts of the 35S promoter derived from Cauliflower Mosaic Virus, the NOS terminator derived from Agrobacterium tumefaciens and the antibiotic marker gene NPTII (neomycin-phosphotransferase II), to allow for general screening of foods. PCR/hybridization protocols were established for the detection of glyphosate-tolerant RoundUp Ready soybean and insect-resistant Bt-maize.