The global distribution of PCBs and organochlorine pesticides in butter.

In this study we explored the use of butter as a sampling matrix to reflect the regional and global scale distribution of PCBs and selected organochlorine pesticides/metabolites in air. This was because persistent organic pollutants (POPs) concentrate in dairy fats, where concentrations are controlled by feed intake (primarily from pasture/silage), which is in turn primarily controlled by atmospheric deposition. Butter sigmaPCB concentrations varied by a factor of approximately 60 in 63 samples from 23 countries.

Human exposure to PCDD/Fs in the UK: the development of a modelling approach to give historical and future perspectives.

In order to assess the long-term impact of persistent organic contaminants such as polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) it is important to be able to quantify historical exposure. An understanding of past exposure is not only important to place our current body burdens in perspective, but is useful in assessing our potential future exposure. Unfortunately, very few direct measurements of our main source of exposure (i.

A congener-specific PCDD/F emissions inventory for the UK: do current estimates account for the measured atmospheric burden?

Considerable effort has been expended in the UK and elsewhere to quantify and rank PCDD/F primary sources and emissions to the environment, principally the atmosphere, so that cost-effective source reduction measures can be taken. Here, we predict a congener-specific emissions inventory for primary and secondary nondioxin-regulated sources to the UK atmosphere, estimated to have ranged from 3 to 22 kg in 1996. The inventory profile is dominated by OCDD (approximately 30-40%), 1,2,3,4,6,7,8-HpCDD (approximately 15-19%) and 1,2,3,4,6,7,8-HpCDF (approximately 14-19%).

Drought-induced guard cell signal transduction involves sphingosine-1-phosphate.

Stomata form pores on leaf surfaces that regulate the uptake of CO2 for photosynthesis and the loss of water vapour during transpiration. An increase in the cytosolic concentration of free calcium ions ([Ca2+]cyt) is a common intermediate in many of the pathways leading to either opening or closure of the stomatal pore. This observation has prompted investigations into how specificity is controlled in calcium-based signalling systems in plants.

A simple (14)C-respirometric method for assessing microbial catabolic potential and contaminant bioavailability.

This paper describes the validation and application of a simple flask-based (14)C-respirometer system designed to assess mineralisation of (14)C-labelled substrates under defined conditions. Validation of this respirometer system indicated stoichiometric CO(2) trapping up to a maximum of 400 micromol of CO(2) (in a single trap). Polycyclic aromatic hydrocarbon (PAH)-degrading bacteria were used to measure growth-linked biodegradation of [(14)C]naphthalene to (14)CO(2).

Impact of composting strategies on the treatment of soils contaminated with organic pollutants.

Chemical pollution of the environment has become a major source of concern. Studies on degradation of organic compounds have shown that some microorganisms are extremely versatile at catabolizing recalcitrant molecules. By harnessing this catabolic potential, it is possible to bioremediate some chemically contaminated environmental systems.

The use of DNA double-strand break quantification in radiotherapy.

DNA double-strand breaks (DSB) are an important direct consequence of treating cells with ionizingradiation. A variety of evidence points toward DSBs being the key damage type linked to radiation-induced lethality. In particular, the link between DSB and chromosome breakage, which in turn closely correlates with cell death in some cell types, is strongly supportive of this concept.

Impact of synthetic pyrethroid-sheep dip on the indigenous microflora of animal slurries.

The chemical constituents of sheep dip in the UK are currently changing from organophosphate-based to synthetic pyrethroid-based insecticides. As a result, changes are also being made to the methods of disposal of these chemicals in the environment, such that pyrethroid sheep dips must now be diluted in animal slurry or water. To date, there is a lack of quantitative information on the impact of the insecticide on the indigenous microflora of animal slurries.

Regulation of leaf and fruit growth in plants growing in drying soil: exploitation of the plants' chemical signalling system and hydraulic architecture to increase the efficiency of water use in agriculture.

In this paper the nature of root-to-shoot signals in plants growing in drying soil is considered in the context of their commercial exploitation in tomato (Lycopersicon esculentum L.) and other crops. Recent findings are presented on the effects of partial root drying (PRD) in the production of a glasshouse tomato crop.

Ca2+signalling in stomatal guard cells.

Ca(2+) is a ubiquitous second messenger in the signal transduction pathway(s) by which stomatal guard cells respond to external stimuli. Increases in guard-cell cytosolic free Ca(2+) concentration ([Ca(2+)](cyt)) have been observed in response to stimuli that cause both stomatal opening and closure. In addition, several important components of Ca(2+)-based signalling pathways have been identified in guard cells, including the cADP-ribose and phospholipase C/Ins(1, 4,5)P(3)-mediated Ca(2+)-mobilizing pathways.

Amino acids as a nitrogen source in temperate upland grasslands: the use of dual labelled ((13)C, (15)N) glycine to test for direct uptake by dominant grasses.

It is becoming increasingly apparent that soil amino acids are a principal source of nitrogen (N) for certain plants, and especially those of N-limited environments. This study of temperate upland grasslands used glycine-2-(13)C-(15)N and ((15)NH4)(2)SO(4) labelling techniques to test the hypothesis that plant species which dominate 'unimproved' semi-natural grasslands (Festuca-Agrostis-Galium) are able to utilise amino acid N for growth, whereas those plants which dominate 'improved' grasslands (Lolium-Cynosurus), that receive regular applications of inorganic fertiliser, use inorganic N forms as their main N source. Data from field experiments confirmed that 'free' amino acids were more abundant in 'unimproved' than 'improved' grassland and that glycine was the dominant amino acid type (up to 42% of total).

Improvements to the UK PCDD/F and PCB atmospheric emission inventory following an emissions measurement programme.

PCDD/F data are presented from 75 samples of primary emissions sampled between 1995-97 as part of the compliance monitoring survey undertaken by the UK Environment Agency. Municipal solid waste (MSW), chemical waste and clinical waste incinerators, cement kilns, sinter plants and sewage sludge incinerators were the source categories monitored and reported here. Based on this monitoring programme, the previous national UK emission estimates by Eduljee and Dyke (1) of 560-1100 g I-TEQ a(-1) for 1993 have been revised downwards to 220-660 g I-TEQ a(-1).

Stable isotope analysis of the origins of zooplankton carbon in lakes of differing trophic state.

Carbon stable isotope analysis was carried out on zooplankton from 24 United Kingdom lakes to examine the hypothesis that zooplankton dependence on allochthonous sources of organic carbon declines with increasing lake trophy. Stable isotope analysis was also carried out on particulate and dissolved organic matter (POM and DOM) and, in 11 of the lakes, of phytoplankton isolates. In 21 of the 24 lakes, the zooplankton were depleted in C relative to bulk POM, consistent with previous reports.

Coping with multiple enemies: an integration of molecular and ecological perspectives.

How plants respond to attack by the range of herbivores and pathogens that confront them in the field is the subject of considerable research by both molecular biologists and ecologists. However, in spite of the shared focus of these two bodies of research, there has been little integration between them. We consider the scope for such integration, and how greater dialogue between molecular biologists and ecologists could advance understanding of plant responses to multiple enemies.

A fingerprinting method for chondroitin/dermatan sulfate and hyaluronan oligosaccharides.

A previously published method for the analysis of glycosaminoglycan disaccharides by high pH anion exchange chromatography (Midura,R.J., Salustri,A.

Ultrastructural localization of sulfated and unsulfated keratan sulfate in normal and macular corneal dystrophy type I.

Keratan sulfate (KS) proteoglycans are of importance for the maintenance of corneal transparency as evidenced in the condition macular corneal dystrophy type I (MCD I), a disorder involving the absence of KS sulfation, in which the cornea becomes opaque. In this transmission electron microscope study quantitative immuno- and histochemical methods have been used to examine a normal and MCD I cornea. The monoclonal antibody, 5-D-4, has been used to localize sulfated KS and the lectin Erythrina cristagalli agglutinin (ECA) to localize poly N -acetyllactosamine (unsulfated KS).

Particles and vegetation: implications for the transfer of particle-bound organic contaminants to vegetation.

This paper presents a comprehensive review of the mechanisms responsible for the transfer of atmospheric particulate deposition and soil particulate re-suspension onto vegetation. The nature of atmospheric aerosols and dry/wet particulate deposition are reviewed, together with information from the literature on radionuclides as tracers of the air particle/soil particle to vegetation transfer processes. Information from these fields is used to make inferences about the potential significance of these pathways in supplying particle-bound semi-volatile organic chemicals (e.

Impact of electrical cable insulating oil on the mineralisation of [1-(14)C]glucose in soil.

Subsurface high voltage electric cables are commonly insulated using dodecylbenzene in combination with mineral oil. This work assessed the impact of increasing concentrations of cable insulating oil (0-10% dry weight) on soil microbial respiration as determined by mineralisation of [1-(14)C]glucose (11 microg C g(-1) soil). Acute impact was assessed from 0 days to 21 days, and chronic impact was assessed after 300 days.

Proteoglycans on normal and migrating human corneal endothelium.

Proteoglycans are of fundamental importance to the normal functioning of the cornea. They consist of a core protein to which one or more glycosaminoglycan chains are attached. Cell surface proteoglycans are known to mediate many aspects of cell behaviour including cell adhesion, control of extracellular matrix deposition, cell proliferation, cell migration, leukocyte adhesion and modulation of growth factor activity.

An improved method for the structural profiling of keratan sulfates: analysis of keratan sulfates from brain and ovarian tumors.

A previously developed method for the structural fingerprinting of keratan sulfates (Brown et al., Glycobiology, 5, 311-317, 1995) has been adapted for use with oligosaccharides fluorescently labeled with 2-aminobenzoic acid following keratanase II digestion. The oligosaccharides are separated by high-pH anion-exchange chromatography on a Dionex AS4A-SC column.

Abscisic acid induces oscillations in guard-cell cytosolic free calcium that involve phosphoinositide-specific phospholipase C.

Oscillations in cytosolic free Ca2+ concentration ([Ca2+]cyt) are an important component of Ca2+-based signal transduction pathways. This fact has led us to investigate whether oscillations in [Ca2+]cyt are involved in the response of stomatal guard cells to the plant hormone abscisic acid (ABA). We show that ABA induces oscillations in guard-cell [Ca2+]cyt.

Abscisic acid-induced stomatal closure mediated by cyclic ADP-ribose.

Abscisic acid (ABA) is a plant hormone involved in the response of plants to reduced water availability. Reduction of guard cell turgor by ABA diminishes the aperture of the stomatal pore and thereby contributes to the ability of the plant to conserve water during periods of drought. Previous work has demonstrated that cytosolic Ca2+ is involved in the signal transduction pathway that mediates the reduction in guard cell turgor elicited by ABA.

pH-regulated leaf cell expansion in droughted plants is abscisic acid dependent.

Elongation rates of barley (Hordeum vulgare L. cv Hanna) leaves decreased with decreasing soil water content, whereas the pH of xylem sap increased from 5.9 to 6.

Non-compliance of beaches with the EU directives of bathing water quality: evidence of non-point sources of pollution in Morecambe Bay.

Morecambe's three EU designated bathing beaches frequently fail the EU directives, even after a state of the art sewage treatment plant has become operational. We have been using conventional microbiology to look at the seasonality and distribution of indicator and pathogenic bacteria in Morcambe Bay and using molecular methods (polymerase chain reaction (PCR) and pulse field gel electrophoresis (PFGE)) to investigate the pathways by which pathogens reach the bathing waters. We will present data for Morecambe Bay which show that: 1.

Human aggrecan keratan sulfate undergoes structural changes during adolescent development.

Alkaline borohydride-reduced keratan sulfate chains were isolated from human articular cartilage aggrecan from individuals of various ages (0-85 years old). The chains were structurally characterized using 1H NMR spectroscopy, gel permeation chromatography, and oligosaccharide profiling (after digestion with the enzymes keratanase and keratanase II). The results show that from birth to early adolescence (0-9 years) the levels of alpha(1-3)-fucosylation, alpha(2-3)-sialylation, and galactose sulfation increase.