Butylated hydroxyanisole inhibits tumor necrosis factor-induced cytotoxicity and arachidonic acid release

The mechanisms by which the antioxidant butylated hydroxyanisole (BHA) inhibits recombinant tumor necrosis factor alpha (rTNF-α)-induced cytotoxicity have been studied in WEHI 164 clone 13 (WEHI) and L929 fibrosarcoma cells. When BHA was added simultaneously with rTNF-α, it completely inhibited rTNF-α cytotoxicity in the WEHI and L929 cells. BHA also inhibited the toxicity when added 2 h after rTNF-α in WEHI cells, suggesting that BHA inhibits some late intracellular event(s) in rTNF-α cytotoxicity. Pretreating WEHI cells with BHA for 4 h did not decrease the binding of rTNF-α to its receptors as measured using flow cytometry. BHA inhibited rTNF-α toxicity in the presence of actinomycin D and cycloheximide, indicating that neither mRNA nor protein synthesis is necessary for the BHA effect. The antioxidant butylated hydroxytoluene (BHT) and indomethacin did not inhibit the rTNF-α-induced cytotoxicity nor the rTNF-α-induced release of [³H]arachidonic acid. By comparison, BHA completely inhibited the rTNF-α-induced release of arachidonic acid, suggesting that BHA somehow inhibits rTNF-α-induced activation of phospholipase(s). In WEHI cells, rTNF-α increased the level of protein-associated thiobarbituric acid reactive substances (TBARS) dose-dependently. BHA, but not BHT, blocked rTNF-α-induced cytotoxicity and rTNF-α-induced accumulation of protein-associated TBARS, suggesting that rTNF-α cytotoxicity is correlated with protein-associated TBARS. In conclusion, the results suggest that BHA blocks some post receptor event in rTNF-α-induced cytotoxicity, and that activation of phospholipase(s) coupled with the enzymatic formation of specific oxidized lipids could be a pivotal event in rTNF-α-induced cytotoxicity.     

Solar material protection factor (SMPF) and solar skin protection factor (SSPF) for window panes and other glass structures in buildings

The two quantities solar material protection factor (SMPF) and solar skin protection factor (SSPF) are introduced in order to measure and calculate the capability of glass to protect indoor materials and human skin from degradation caused by the solar radiation. Comparison of the SMPF and SSPF values for different glass fabrications enables one to select the most appropriate glass material for the specific buildings. Numerical examples are shown with measurements and calculations carried out on various glass materials, including two electrochromic window (ECW) devices, and several two- and three-layer window pane combinations. Visibility levels at various protection degrees are also given.     

Implementation of a GIS-based management tool for conservation of biodiversity within the municipality of Oslo, Norway

Tools to effectively apply biological information in daily physical planning cases are viewed as essential in order to preserve and manage natural habitats in highly pressured urban areas. This paper describes a GIS-based management tool for conservation and management of biodiversity and the process of implementation in the capital of Oslo, Norway. The main objective of this multi-agency effort is to ensure a sustainable and responsible management of the biodiversity within the municipality. A political decision on the state level encourages all municipalities to survey and classify their biological diversity according to a scale of importance within 2003. Furthermore the results from the survey were encouraged to be implemented in the daily physical planning at a local level. The assignment called for structured, classified and accessible information about the biological resources of the municipality. The electronic tool presented makes it possible to combine biological information with any other information that is relevant for a planning issue. We believe the GIS-based management tool has a strong potential to be transferred to other municipalities in Norway as well as to other countries with organised environmental management systems at both local, regional and national levels.     

Biometrical modelling in genetics: are complex traits too complex?

The field of traditional biometrical genetics uses mixed-effects models to quantify the influence of genetic and environmental factors on a biological trait, based essentially on estimating within-family trait correlations. Such analyses provide a useful preview of what may be discovered with the emerging full-scale genotyping strategies. However, biometrical analyses require unrealistically large sample sizes to obtain a reasonable precision, particularly for dichotomous traits. In addition, it may be very difficult to separate genetic and environmental effects because environmental correlations are poorly understood. We illustrate these and other difficulties using population-based cousins and nuclear family data for birth weight, collected from the Medical Birth Registry of Norway.     

The quantum confined Stark effect in silicon nanocrystals

The quantum confined Stark effect (QCSE) in Si nanocrystals embedded in a SiO(2) matrix is demonstrated by photoluminescence (PL) spectroscopy at room and cryogenic temperatures. It is shown that the PL peak position shifts to higher wavelengths with increasing applied electric field, which is expected from carrier polarization within the quantum dots. It is observed that the effect is more pronounced at lower temperatures due to the improved carrier localization at the lowest energy states of the quantum dots. Experimental results are shown to be in good agreement with phenomenological model developed for the QCSE model.     

Whose uncertainty assessments (probability distributions) does a risk assessment report: the analysts' or the experts'?

It is often said that the aim of risk assessment is to faithfully represent and report the knowledge of some defined experts in the field studied. The analysts' job is to elicit this knowledge, synthesise it and report the results as integrated uncertainty assessments, for example, expressed through a set of probability distributions. Analysts' judgements beyond these tasks should not be incorporated in the uncertainty assessments (distributions). The purpose of the present paper is to discuss the rationale of this perspective. To conduct a risk assessment in practice the analysts need to make a number of judgements related to, for example, the choice of methods and models that to a large extent influence the results. And often the analysts are the real experts on many of the issues addressed in the assessments, in particular, when it comes to understanding how various phenomena and processes interact. Would it then not be more appropriate to fully acknowledge the role of the analysts as uncertainty assessors and probability assigners, and see the results of the risk assessments as their judgements based on input from the experts? The discussion is illustrated by two examples.     

Probabilistic capacity models and seismic fragility estimates for RC columns subject to corrosion

In this paper, probabilistic drift and shear force capacity models are developed for corroding reinforced concrete (RC) columns. The developments represent a merger between a probabilistic model for chloride-induced corrosion, a time-dependent corrosion rate, and previously developed probabilistic models for drift and shear force capacity of pristine (undamaged) RC columns. Fragility estimates are obtained for an example corroding column by applying the developed models at given shear and drift demands. Model uncertainties in both the capacity and corrosion models are considered in the fragility estimation, in addition to uncertainties in environmental conditions, material properties, and structural geometry. Sensitivity analyses of the corroding RC column are carried out to identify the parameters to which the reliability of the example column is most sensitive. The developed models consider different combinations of chloride exposure condition, environmental oxygen availability, water-to-cement ratios, and curing conditions. They are applicable to both existing and new RC columns and may be employed for the prediction of service-life and life-cycle cost analysis of RC structures.     

On risk assessment in the petroleum activities on the Norwegian and UK continental shelves

This article discusses some key principles and tools of safety management, with focus on risk analyses, risk interpretation, risk acceptance criteria and risk communication, as well as emergency preparedness. The starting point for the discussion is the experience from the activity on the Norwegian and UK continental shelves, and the implementation of new safety regulations in particular.     

Propeller blade stresses,application of finite element methods

This paper presents results from application of shell elements for prediction of quasi static and dynamic stresses in marine propeller blades.Stresses and deformations calculated for ordinary geometry and highly scewed propellers are compared with experiments.Specially designed data generators are employed to facilitate the helicoidal geometry involved.