Exposure of the general public due to wireless LAN applications in public places.

The typical exposure caused by wireless LAN applications in public areas has been investigated in a variety of scenarios. Small-sized (internet café) and large-scale (airport) indoor scenarios as well as outdoor scenarios in the environment of access points (AP) supplying for residential areas and public places were considered. The exposure assessment was carried out by numerical GTD/UTD computations based on optical wave propagation, as well as by verifying frequency selective measurements in the considered scenarios under real life conditions.

Measurements and simulations of the radiation exposure to aircraft crew workplaces due to cosmic radiation in the atmosphere.

As required by the European Directive 96/29/Euratom, radiation exposure due to natural ionizing radiation has to be taken into account at workplaces if the effective dose could become more than 1 mSv per year. An example of workers concerned by this directive is aircraft crew due to cosmic radiation exposure in the atmosphere. Extensive measurement campaigns on board aircrafts have been carried out to assess ambient dose equivalent.

A comparative analysis of polyurethane hydrogel for immobilization of IgG on chips.

Hydrogels are considered an optimum material for protein chip surfaces, since they provide a quasi-liquid environment which allows protein activity to be maintained and shows good spot morphology as well as excellent immobilization capacity. In the following, we present a polyurethane (PU) chip that electrostatically binds IgG. The PU surface is optimized with regard to layer thickness (approximately 200 nm), hydrogel (2%) and immobilized antibody concentration (0.

Pharmacoresistance in epilepsy: a pilot PET study with the P-glycoprotein substrate R-[(11)C]verapamil.

Purpose And Methods: Regional overexpression of the multidrug transporter P-glycoprotein (P-gp) in epileptic brain tissue may lower target site concentrations of antiepileptic drugs and thus contribute to pharmacoresistance in epilepsy. We used the P-gp substrate R-[(11)C]verapamil and positron emission tomography (PET) to test for differences in P-gp activity between epileptogenic and nonepileptogenic brain regions of patients with drug-resistant unilateral temporal lobe epilepsy (n = 7). We compared R-[(11)C]verapamil kinetics in homologous brain volumes of interest (VOIs) located ipsilateral and contralateral to the seizure focus.

High-resolution numerical model of the middle and inner ear for a detailed analysis of radio frequency absorption.

In order to enable a detailed analysis of radio frequency (RF) absorption in the human middle and inner ear organs, a numerical model of these organs was developed at a spatial resolution of 0.1 mm, based on a real human tissue sample. The dielectric properties of the liquids (perilymph and endolymph) inside the bony labyrinth were measured on samples of ten freshly deceased humans.

Reliable allele detection using SNP-based PCR primers containing Locked Nucleic Acid: application in genetic mapping.

Background: The diploid, Solanum caripense, a wild relative of potato and tomato, possesses valuable resistance to potato late blight and we are interested in the genetic base of this resistance. Due to extremely low levels of genetic variation within the S. caripense genome it proved impossible to generate a dense genetic map and to assign individual Solanum chromosomes through the use of conventional chromosome-specific SSR, RFLP, AFLP, as well as gene- or locus-specific markers.

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.

Nuclear export of the transcription factor NirA is a regulatory checkpoint for nitrate induction in Aspergillus nidulans.

NirA, the specific transcription factor of the nitrate assimilation pathway of Aspergillus nidulans, accumulates in the nucleus upon induction by nitrate. NirA interacts with the nuclear export factor KapK, which bridges an interaction with a protein of the nucleoporin-like family (NplA). Nitrate induction disrupts the NirA-KapK interaction in vivo, whereas KapK associates with NirA when this protein is exported from the nucleus.

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.

Modelling critical levels of ozone for the forested area of Austria. Modifications of the AOT40 concept.

Goal, Scope And Background: Ozone is the most important air pollutant in Europe for forest ecosystems and the increase in the last decades is significant. The ozone impact on forests can be calculated and mapped based on the provisional European Critical Level (AOT40 = accumulated exposure over a threshold of 40 ppb, 10,000 ppb x h for 6 months of one growing season calculated for 24 h day(-1)). For Norway spruce, the Austrian main tree species, the ozone risk was assessed in a basis approach and because the calculations do not reflect the health status of forests in Austria, the AOT40 concept was developed.

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.

Nitrate dynamics in an Alpine forest site (Mühleggerköpfl). O and N stable isotope analysis in natural water samples.

Stable isotope analysis of 15N/14N and 18O/16O-nitrate was used to investigate the nitrate dynamics and potential groundwater pollution in an Alpine forest stand in Tyrol/Austria. The dynamics of delta15-N(nitrate) values were followed in a forest ecosystem. The stable isotopic values of the throughfall are comparable with other studies.

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.

Application of the popliteal lymph node assay in immunotoxicity testing: complementation of the direct popliteal lymph node assay with flow cytometric analyses.

The popliteal lymph node assay (PLNA) has been proposed to measure the immunosensitizing potential of chemicals. The direct PLNA detects an immunomodulating effect but does not give insight into the mode of action of the chemical under test. Modifications of this test have been proposed, but they are difficult to perform in routine toxicity testing and require many animals.

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.

Radiocaesium contamination of meadow vegetation--time-dependent variability and influence of soil characteristics at grassland sites in Austria.

Long-term trends of 137Cs and 40K concentrations in meadow grass and soil-plant transfer data at eight different sites in Upper Austria are presented. Geometric means of 137Cs TF-data and Tagg values vary between 0.03-1.

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.

Microbial population structures in soil particle size fractions of a long-term fertilizer field experiment.

Soil structure depends on the association between mineral soil particles (sand, silt, and clay) and organic matter, in which aggregates of different size and stability are formed. Although the chemistry of organic materials, total microbial biomass, and different enzyme activities in different soil particle size fractions have been well studied, little information is available on the structure of microbial populations in microhabitats. In this study, topsoil samples of different fertilizer treatments of a long-term field experiment were analyzed.

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.

Influence of molecular structure on sorption of phenoxyalkanoic herbicides on soil and its particle size fractions.

The sorption and desorption behaviors of four phenoxyalkanoic acid herbicides and their metabolites on four agricultural soils and soil particle size fractions were examined. Generally, there was a trend of increasing adsorption and decreasing desorption in the order mecoprop < MCPA < dichlorprop < 2,4-D. The significant increase in adsorption of the phenolic metabolites can be explained by their lower polarity and enhanced partition in the organic soil matrix.