Geostatistical approach for assessing soil volumes requiring remediation: validation using lead-polluted soils underlying a former smelting works

Assessing the volume of soil requiring remediation and the accuracy of this assessment constitutes an essential step in polluted site management. If this remediation volume is not properly assessed, misclassification may lead both to environmental risks (polluted soils may not be remediated) and financial risks (unexpected discovery of polluted soils may generate additional remediation costs). To minimize such risks, this paper proposes a geostatistical methodology based on stochastic simulations that allows the remediation volume and the uncertainty to be assessed using investigation data. The methodology thoroughly reproduces the conditions in which the soils are classified and extracted at the remediation stage. The validity of the approach is tested by applying it on the data collected during the investigation phase of a former lead smelting works and by comparing the results with the volume that has actually been remediated. This real remediated volume was composed of all the remediation units that were classified as polluted after systematic sampling and analysis during clean-up stage. The volume estimated from the 75 samples collected during site investigation slightly overestimates (5.3% relative error) the remediated volume deduced from 212 remediation units. Furthermore, the real volume falls within the range of uncertainty predicted using the proposed methodology.     

Glutamatergic innervation in bone

Bone is highly innervated, and evidence for a regulation of bone metabolism by nerve fibers has been suggested by many clinical and experimental studies. However, the nature of the neuromediators involved in these processes has not been well documented. Glutamate (Glu), a major neuromediator of the central nervous system (CNS), was recently identified in nerve fibers running in bone marrow in close contact with bone cells, suggesting that Glu may also act as a neuromediator in this tissue. During the last few years, all the machinery required for glutamate signalling in the CNS was demonstrated in bone. Osteoblasts and osteoclasts express ionotropic Glu receptors (iGluR) (NMDA, AMPA, and Kainate) and metabotropic Glu receptors (mGluR) as well as Glu transporters. Electrophysiological studies have demonstrated that NMDA receptors (NMDAR) and mGluR are functional on bone cells. NMDAR are involved in osteoclast formation and bone resorption and preliminary studies suggest that they may also participate in mechanisms underlying osteoblast proliferation or differentiation, providing evidence for a direct action of Glu on bone cells. The bone loss induced in a model of sciatic neurectomy in growing rats is associated with a decrease of glutamatergic innervation, suggesting that Glu released by nerve fibers may contribute to the regulation of bone remodeling. The manipulation of Glu action in bone may, therefore, represent a new therapeutic target for pathologies associated with modifications of bone remodeling.     

Single hair cocaine consumption monitoring by mass spectrometric imaging

Matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI) was used to image the distribution of cocaine and its metabolites in intact single hair samples from chronic users down to a concentration of 5 ng/mg. Acquisitions were performed in rastering mode, at a speed of 1 mm/s and in the selected reaction monitoring (SRM) mode on a MALDI triple quadrupole linear ion trap fitted with a high repetition rate laser (1 kHz). Compared to traditional methods based on LC-MS/MS or GC-MS(/MS) which require to segment the hair to obtain spatial resolution, MALDI-MSI, with a straightforward sample preparation beforehand, allowed obtaining a spatial resolution of 1 mm and thus the chronological information about cocaine consumption contained in a single intact hair over several months could be monitored. The analysis time of an intact single hair sample of 6 cm is approximately of 6 min. Cocaine and its metabolites benzoylecgonine, ethylcocaine, and norcocaine were investigated in nine sets of hair samples for forensic purposes. The analyses were accomplished by spraying α-cyano-4-hydroxycinnamic acid (CHCA), 4-chloro-α-cyano-cinnamic acid (Cl-CCA), or (E)-2-cyano-3-(naphthalen-2-yl)acrylic acid (NpCCA) as MALDI matrices. We also propose a rapid strategy for sensitive confirmatory analyses with both MS/MS and MS(3) experiments performed directly on intact hair samples. Since only part of the hair strand is analyzed, additional analyses are possible at any time on the remaining hair from the strand.     

Modulation of the activity of the NADPH oxidase system by reactive oxygen species: influence of catalase

The nicotinamide adenine dinucleotide phosphate oxidase complex (Nox) is a major source of non-mitochondrial reactive oxygen species in cells. Nox contains both membrane (Cytb(558)) and cytosolic (p40(phox), p47(phox), p67(phox) and Rac) components. Nox has been submitted to a combination of oxygen free radicals produced by irradiation and to hydrogen peroxide. Irradiation of a single component with high doses led to partial inactivation; however, the irradiation of the whole system during its assembly phase with lower doses (2-10 Gy) led either to activation (2.7 Gy) or to strong inactivation if irradiation took place during the first minute of the assembly. Incubation of the membrane fractions or of p67(phox) with H(2)O(2) led to fast inactivation. Catalase protected weakly p67(phox) from H(2)O(2). Conversely, incubation of the membrane fractions with catalase led to over-activation of the system.     

Radio frequency heating of foods: principles, applications and related properties--a review

Radio frequency (RF) heating is a promising technology for food applications because of the associated rapid and uniform heat distribution, large penetration depth and lower energy consumption. Radio frequency heating has been successfully applied for drying, baking and thawing of frozen meat and in meat processing. However, its use in continuous pasteurization and sterilization of foods is rather limited. During RF heating, heat is generated within the product due to molecular friction resulting from oscillating molecules and ions caused by the applied alternating electric field. RF heating is influenced principally by the dielectric properties of the product when other conditions are kept constant. This review deals with the current status of RF heating applications in food processing, as well as product and system specific factors that influence the RF heating. It is evident that frequency level, temperature and properties of food, such as viscosity, water content and chemical composition affect the dielectric properties and thus the RF heating of foods. Therefore, these parameters should be taken into account when designing a radio frequency heating system for foods.     

Autonomy and Competence in German and American University Students: A Comparative Study Based on Self-Determination Theory.

According to self-determination theory (R. M. Ryan & E. L. Deci, 2000), supports for autonomy and competence are essential for growth and well-being in any learning environment. Educational contexts differ in their relative support for these 2 needs. The authors examined the role of autonomy and competence in 2 German and 2 American university settings, as they were predicted to differ in terms of their relative emphasis on competence versus autonomy. Invariance analyses supported the construct comparability of the measures and demonstrated that German students felt significantly more autonomous and less competent than American students. Perceived pressures and positive informational feedback were modeled as antecedents of autonomy and competence, and well-being was examined as a consequence. The hypothesized model was generally supported across the 4 samples. (PsycINFO Database Record (c) 2010 APA, all rights reserved)