Azo dyes, extensively used for coloring a variety of consumer goods, such as leather, clothes, food, and toys, can under certain conditions be reduced to form confirmed or suspected carcinogenic aromatic amines. This article gives an overview of the state of development of analytical procedures for the determination of such azo dyes, which are banned by the European Commission. (C) 2004 Elsevier L

Heat shock proteins counteract heat and oxidative stress. In chloroplasts, a small heat shock protein (Hsp21) contains a set of conserved methionines, which date back to early in the emergence of terrestrial plants. Methionines M49, M52, M55, M59, M62, M67 are located on one side of an amphipathic helix, which may fold back over two other conserved methionines (M97 and M101), to form a binding gro

Do moor frog (Rana arvalis) and common frog (R. temporaria) tadpoles increase developmental rate if there is a risk of their pond drying up before metamorphosis? To study this, I performed an experiment designed to mimic natural conditions in many drying ponds. The number of tadpoles per tank was constant during the experiment but the water level was lowered in experimental tanks so that crowding

In this work the steady and unsteady flamelet models have been applied to soot formation in laminar and turbulent diffusion flames. The aim was to study how different model parameters affect soot formation in diffusion flames. It was shown that certain assumptions are more crucial in laminar diffusion flames than in turbulent ones. The soot formation in turbulent diffusion flames is more sensitive

From an inside point of view, the concept of a "unified science of materials" might appear to be quite natural in its own right, as it were. However, considering the fact that science in general is practiced by humans in a social environment, it should be warranted to examine materials science also from the humanistic and sociological perspectives, as well as against the background of current thin

Extended X-ray absorption fine structure has been utilised to determine the structural parameters of the amorphous III-V semiconductors GaP, GaAs, InP and InAs. The amorphous phase was formed by ion implantation to inhibit preparation-specific artefacts associated with the alternative fabrication techniques of sputtering and evaporation. Relative to crystalline standards, increases in bond length

Discussion of various appraoches to use films as historical source material.

The main purpose of this study is to develop a SPME calibration method suitable for use in evaluation of concentrations of hydrophobic substances in environmental samples. The analyte used in the experiments was alpha-pinene, a hydrophobic organic compound commonly found in wood, and therefore found in wood storage facilities, wood processing industries and wood based biofilters. The SPME fibres w

Consider a spatial multibody system with rigid and elastic bodies. The bodies are linked by rigid interconnections (e.g. revolute joints) causing constraints, as well as by flexible interconnections (e.g. springs) causing applied forces. Small motions of the system with respect to a given nominal configuration can be described by linearized dynamic equations and kinematic constraint equations. We

Plasmodium falciparum is the causative agent of the most severe type of malaria, a life-threatening disease affecting the lives of over three billion people. Factors like widespread resistance against available drugs and absence of an effective vaccine are seriously compounding control of the malaria parasite. Thus, there is an urgent need for the identification and validation of new drug targets.

Individual variation of the female sex pheromone signal in Agrotis segetum was determined by gas chromatographic analysis. The individuals varied extensively, both in absolute and relative amounts of the three major pheromone components; Z5-10:OAc, Z7-12:OAc and Z9-14:OAc. Within individuals there was a strong correspondence between the sex pheromone gland content and the signal actually emitted.

The metallation of tetrapyrroles is believed to proceed via a sitting-atop (SAT) complex, in which some of the pyrrole nitrogen atoms are protonated and the metal ion resides above the ring plane. No crystal structure of such a complex has been presented, but NMR and EXAFS (extended X-ray absorption fine structure) data has been reported for Cu2+ in acetonitrile, which have been interpreted as the