PBDEs, PBBs, and PCNs in three communities of free-ranging killer whales (Orcinus orca) from the northeastern Pacific Ocean

Polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), and polychlorinated naphthalenes (PCNs) were quantified in blubber biopsy samples collected from free-ranging male and female killer whales (Orcinus orca) belonging to three distinct communities (southern residents, northern residents, and transients) from the northeastern Pacific Ocean. High concentrations of sigmaPBDE were observed in male southern residents (942+/-582 ng/g Iw), male and female transients (1015+/-605 and 885+/-706 ng/g Iw, respectively), and male and female northern residents (203+/-116 and 415+/-676 ng/g Iw, respectively). Because of large variation within sample groups, sigmaPBDE levels generally did not differ statistically with the exception of male northern residents, which had lower sigmaPBDE concentrations than male southern residents, male transients, and female transients, perhaps reflecting the consumption of less contaminated prey items. Male transient killer whales, which consume high trophic level prey including other cetaceans and occasionally spend time near populated areas, had sigmaPBDE concentrations approximately equal to southern residents. No significant age-related relationships were observed for sigmaPBDE concentrations. sigmaPBDE concentrations were approximately 1-3 orders of magnitude greater than those of sigmaPBB (3.0-31 ng/g Iw) and sigmaPCN (20-167 ng/g Iw) measured in a subset of samples, suggesting that PBDEs may represent a contaminant class of concern in these marine mammals.     

Rapidly increasing polybrominated diphenyl ether concentrations in the Columbia River system from 1992 to 2000

Concentrations and congener patterns of 32 individual PBDE congeners from mono- through hexa-brominated were investigated in two fish species occupying similar habitats--but having different diets and trophic levels--and surficial sediments from several locations on the major river system of western North America, the Columbia River, in southeastern British Columbia, Canada. Total PBDE concentrations have increased by up to 12-fold over the period from 1992 to 2000 in mountain whitefish from the Columbia River, with a doubling period of 1.6 years. The rate at which PBDE concentrations are increasing in whitefish is greater than has been previously reported worldwide. At the current rate of increase, sigmaPBDE will surpass those of sigmaPCB by 2003 to become the most prevalent organo-halogen contaminant in this region. SigmaPBDE in whitefish from the mainstem of the Columbia River range up to 72 ng/g wet weight, concentrations that are 20-50-fold higher than in a nearby pristine watershed affected only by atmospheric contaminant transport. Conversely, sigmaPBDE in largescale suckers were approximately an order of magnitude lower than in whitefish, demonstrating the influence of biomagnification and feeding habits. Congener patterns in whitefish from the Columbia River directly correlated with the two major commercial penta-BDE mixtures in use and represent the first time free-swimming aquatic biota such as fish have been found to contain PBDE congener patterns so similar to commercial mixtures. PBDE concentrations in sediments were not linked to a variety of investigated point sources but were instead inversely correlated with the ratio of organic carbon:organic nitrogen in surficial sediments with a pattern suggesting the dominant influence of septic field inputs from the primarily rural population.     

Guidance on individual monitoring programmes for radioisotopic techniques in molecular and cellular biology

The radioisotope techniques used in molecular and cellular biology involve external and internal irradiation risk. The personal dosemeter may be a reasonable indicator for external irradiation. However, it is necessary to control the possible internal contamination associated with the development of these techniques. The aim of this project is to analyse the most usual techniques and to establish programmes of internal monitoring for specific radionuclides (32P, 35S, 14C, 3H, 125I and 131I). To elaborate these programmes it was necessary to analyse the radioisotope techniques. Two models have been applied (NRPB and IAEA) to the more significant techniques, according to the physical and chemical nature of the radionuclides, their potential importance in occupational exposure and the possible injury to the genetic material of the cell. The results allowed the identification of the techniques with possible risk of internal contamination. It was necessary to identify groups of workers that require individual monitoring. The risk groups have been established among the professionals exposed, according to different parameters: the general characteristics of receptor, the radionuclides used (the same user can work with one, two or three radionuclides at the same time) and the results of the models applied. Also a control group was established. The study of possible intakes in these groups has been made by urinalysis and whole-body counter. The theoretical results are coherent with the experimental results. They have allowed guidance to individual monitoring to be proposed. Basically, the document shows: (1) the analysis of the radiosotopic techniques, taking into account the special containment equipment; (2) the establishment of the need of individual monitoring; and (3) the required frequency of measurements in a routine programme.     

Search engines as a security threat

Because they implement vulnerable security policies, search engines are excellent tools for helping hackers to attack machines anonymously, search for easy targets or gather confidential data. Securing all channels against hackers trying to penetrate a vulnerable system isn't possible, but there is no reason for search engines to be wide-open channels that continue to help hackers find and penetrate weak systems. Because it is so easy to use a search engine to cloak an attack, search-engine-based hacker abuse has become a real threat that poses serious risks. However, not all blame should fall on those who operate the search engines. Search engines aren't responsible for the huge numbers of poorly configured and insecure machines all over the Internet even if the search engines do aid in identifying them, but the search engines must take some blame if they continue to provide easy ways to locate weak and penetrable machines     

From Documents to Applications Using Markup Languages

This document- oriented approach to developing content- intensive applications uses markup languages to involve domain experts in development and to simplify application production and maintenance.     

Characterisation and evolution of a soil affected by olive oil mill wastewater disposal.

A location used for 10 years as an uncontrolled olive oil mill wastewater disposal site is studied in this work. Once it was closed the sedimented solid waste on the soil surface was removed. In order to evaluate the influence upon soil characteristics, morphological aspects and analytical parameters of a soil profile from the affected zone are compared to those of a control soil located near the landfill. The residual contamination levels in the underlying soil are determined. The results show that the wastewater infiltration in the soil has caused carbonate dissolution and redistribution and modifications in pH values, electrical conductivity, nutrient contents, phenolic compounds and biological activity of the horizons. Removal of waste, natural leaching and biological activity, in time, led to an effective decrease in electrical conductivity and phenolic compounds, although residual levels can be important even 2 years later.     

Spectral analysis of electrograms during ventricular tachycardia in a canine model: relation with epicardial isochronal maps

The purpose of this study was to assess the capability of magnitude-squared coherence and bicoherence to differentiate monomorphic ventricular tachycardia (MVT) and polymorphic ventricular tachycardia (PVT) in a canine model and to relate these results to the epicardial isochronal maps on a beat-to-beat basis. Unipolar electrograms were simultaneously recorded from the surface of both ventricles with a 127-lead sock electrode array in 12 open-chest anesthetized dogs. The sampling frequency was 500 Hz. Atrioventricular block was induced by formaldehyde injection into the atrioventricular node. The left anterior descending coronary artery was occluded for 60 minutes under ventricular pacing (140 beats/min). During reperfusion, 12 MVT episodes lasting more than 42 seconds were recorded. Left stellate ganglion stimulation induced five PVT episodes lasting more than 42 seconds. Each of these recordings was divided into seven segments of 3,072 points (6.144 seconds). After visual selection, 104 segments were extracted and classified as 73 MVT and 31 PVT segments. Magnitude-squared coherence was estimated as the cross-spectrum from two epicardial signals (on the right and left ventricles, respectively), normalized with the respective autopower spectrum. Bicoherence was estimated as the bispectrum normalized with the autopower spectrum. Magnitude-squared coherence correctly identified 96% of MVT and 81% of PVT segments for a total accuracy of 91%. Bicoherence estimated with the left ventricular lead correctly identified 100% of MVT and 77% of PVT segments with an accuracy of 93%. Beat-to-beat epicardial maps of MVT displayed a cluster of sites of origin close to the reperfusion area, while the sites of origin from beats during PVT were much more dispersed over both ventricles. A strong and significant correlation was found between the number of electrodes with the earliest epicardial activation and coherence (r = .76, P < .0001) and bicoherence (r = .68, P < .0001), respectively. A high and significant correlation was also found between both spectral estimators (r = .74, P < .0001). Coherence and bicoherence discriminated accurately between MVT and PVT. Coherence achieved better results compared with bicoherence. Coherence and bicoherence measurements showed a quantitative relation with the spatial dispersion of the sites of origin. Both spectral techniques seemed powerful enough to be used in the development of implantable devices.     

MILORD: The architecture and the management of linguistically expressed uncertainty

The objective of this article is to describe the MILORD Shell and particularly its architecture and its management of uncertainty. MILORD is an expert systems building tool consisting of two inference engines and an explanation module. the system allows one to perform different calculi of uncertainty on an expert defined set of linguistic terms expressing uncertainty. Each calculus corresponds to specific conjunction, disjunction, and implication operators. the internal representation of each linguistic uncertainty value is a fuzzy subset of the interval [0,1]. the different calculi of uncertainty applied to the set of linguistic terms give, as a result, a fuzzy subset that is approximated, by means of a linguistic approximation process, to a linguistic certainty value belonging to the set of linguistic terms. This linguistic approximation keeps the calculus of uncertainty closed. This has the advantage that, once the linguistic certainty values have been defined, the system computes, off-line, the conjunction, disjunction, and implication operations for all the pairs of linguistic uncertainty values in the term set and stores the results in matrices. Therefore, when MILORD is run, the propagation and combination of uncertainty is performed by simply accessing these precomputed matrices. MILORD also deals with nonmonotonic reasoning in the same framework of uncertainty management. Finally, an application to the diagnosis and treatment of pneumoniae is presented.     

Fatty acid composition and sensory characteristics of lamb carcasses from Britain and Spain

Fatty acid composition of intramuscular fat in M. Longissimus was measured in four groups of lambs representing two Spanish breeds: Rasa Aragonesa (RA) and Merino (ME) and two British lamb types: the Welsh Mountain breed (WM), whose carcasses were purchased in Spain and typical early lambs (EL) purchased in Britain. The lambs grown in Spain were concentrate fed and slaughtered at a lighter weight and lower age than those grown in Britain. The British lamb carcasses purchased in Spain were of a similar weight to the Spanish lambs but were lighter than the lamb carcasses purchased in Britain. The British lambs were grass fed. Relationships between fatty acid (FA) composition and sensory attributes were examined following sensory testing of all lambs by both British and Spanish taste panels. The production system was shown to be more important than breed in determining FA composition. British lambs had higher percentages, within total fatty acids, of 18:0, 18:3 (n-3) and long chain polyunsaturated n-3 FA and lower percentages of 18:2 (n-6) and long chain polyunsaturated n-6 FA than Spanish lambs. These differences were due to the different feeding systems used. The amounts of these FA in muscle (mg/100 g) were also different between the British and Spanish groups, not only because the British lambs had more total fat. For both taste panels, odour and flavour intensity were positively correlated with the amounts and percentages of 18:0 and 18:3 and negatively correlated with those of 18:2. This was explained by the fact that both panels gave higher odour and flavour intensity scores to the grass-fed British lamb with high 18:3 levels and lower scores to the concentrate-fed Spanish lamb with high 18:2 levels. However, 18:0 and 18:3 were positively correlated with flavour quality and overall appraisal for the British panel and negatively for the Spanish panel. Conversely, 18:2 was a positive contributor to flavour and overall preference for the Spanish panel and was negative for the British panel. The results show that the production system affects muscle fatty acid composition and the flavour of lamb. However, people's preference is determined to a large extent by their past experience.