Xenon isotopes in nanodiamonds and other presolar grains

pdf freely available cb 18/07/0

De l’idéologie de l’espace à l’idéologie dans l’espace

Plutôt que d'étudier les dimensions idéologiques du discours des géographes, cet article s'interroge sur la pertinence et les méthodes possibles d'une lecture de l'inscription de la dimension idéologique d'une société dans l'espace que celle-ci a produit. Rappelant l'importance d'une réflexion géographique sur les caractéristiques spatiales liées à l'idéologie d'une formation sociale, les auteurs s'appuient sur les études ayant pour but de mesurer la qualité de la vie, telle que perçue par les habitants, ainsi que sur celles portant sur la perception et l'économie politique du risque nucléaire pour reconnaître l'intérêt et la possibilité, sous certaines conditions, d'une étude scientifique des faits idéologiques, tels qu'en dernière analyse ils se lisent dans l'espace géographique lui-même.Rather than studying the ideological dimension of geographical discourse, this article addresses the question of the relevance and possible methodology for analyzing ideological dimensions, within the space created by a given society. Recalling the importance of a geographical approach to spatial characteristics linked to the ideologies of social formations, the authors base their work on studies whose aim is to measure the quality of life, as perceived by the population, as well as those dealing with the awareness and political economy of nuclear risks, to define the relevance and feasibility, under certain circumstances, of the scientific study of ideological phenomena, such as can be ascertained, in the final analysis, from a given geographical space

Search for Q: single grains Xe isotope analysis of carbonaceous residue from Yilmia

We analyse Xe in single grains in HF-HCl residue from Yilmia using RELAX mass spectrometer

A Comparison of Rainfall Estimation Techniques

This study compares two techniques that have been developed for rainfall and streamflow estimation with the aim of identifying strengths and weaknesses of each. The first technique utilises thin plate smoothing splines to develop rainfall surfaces for the catchment, which are then, in conjunction with daily point-wise rainfall data used to determine areal catchment estimates. The second technique develops a regression-based model relating elevation to total annual rainfall in order to scale rainfall for daily mean catchment rainfall estimates. Both approaches are compared in common catchments in the upper Murrumbidgee catchment. The comparison includes using the data from each of the approaches as input to a rainfall-runoff model and by comparison of the quality of modelled results to observed streamflow. The strengths, weaknesses and use for catchment managers in decision making are identified. The study results revealed that where rain station spatial density and data quality are high, both regression and the spline method perform equally as well in estimating long term rainfall trends. In conclusion, catchment managers could apply the simple regression technique over the sophisticated spline method to achieve the comparable results. This is particularly useful where an efficient yet simple method is required for assessing streamflow within similar catchments

Hydropyrolysis of high molecular weight organic matter in Murchison

Hydropyrolysis of the Murchison macromolecular material releases polyaromatic compounds including phenanthrene, carbazole, fluoranthene, pyrene, chrysene, perylene, benzoperylene and coronene units with varying degrees of alklyation

Exfiltration from sewers - is it a serious problem?

This paper contends that estimates of exfiltration leakage from sewers, and the problems arising from it may be too high due to an underestimation of the “self-repairing” action of sewage and sewage sediments in raw sewage. Two aspects of a continuing programme of research are reported;(i) the measurement of exfiltration rates from a range of defects in a sewer pipe with pipe bedding effects simulated by a dry gravel trench surround to the pipe, and (ii) an assessment of the persistence of pathogens in the gravel and soil beneath the test rig pipe, using coliforms as a biological indicator. The results show that the introduction of a gravel surround resulted in more rapid and effective sealing across the entire range of defects tested compared to previously performed experiments with the defects discharging to air. Complete sealing eventually occurred on every run for a 10 mm x 10 mm defect situated at the invert of the sewer and the lowest recorded levels in each experiment for a 10 mm wide radial defect were of the order 10-3 to 10-4 ls-1. These results have been scaled-up to estimate leakage rates in lengths of sewers and sub-catchments and levels significantly lower than previously estimated are indicated. Additionally, the pilot experiment to investigate the fate of biological contaminants in the exfiltrate suggests rapid reduction in microorganisms levels beneath the sewer pipe

Optimization and cost estimation of microalgal lipid extraction using ozone-rich microbubbles for biodiesel production

Harvesting and extracting lipids from the microalgal biomass are the most expensive processes in biodiesel production. This study focuses on reducing the lipid extraction cost using ozone-rich microbubbles technique. The lipid extraction of Dunaliella salina slurry with methanol (1:2 v/v) was performed in a 0.2 L bioreactor at room temperature with direct ozonation (8 mg L−1). When the temperature was increased (60 ̊C) and smaller bubbles were introduced during extraction, the concentration of products increased significantly to around 156%, 88.9% and 150% for 6,10,14-trimethylpentadecan-2-one, palmitic acid and stearic acid, respectively. The energy usage for extracting D. salina lipid with ozone has been estimated to be around 2.16 MJ kg−1 dry algae (36% energy) which is a small fraction of the energy that is used in the production of biodiesel, unlike centrifugation and solvent extraction methods, which consume more than 90% of the energy

The effects of ozone on immune function.

A review of the literature reveals that ozone (O3) exposure can either suppress or enhance immune responsiveness. These disparate effects elicited by O3 exposure depend, in large part, on the experimental design used, the immune parameters examined as well as the animal species studied. Despite the apparent contradictions, a general pattern of response to O3 exposure can be recognized. Most studies indicate that continuous O3 exposure leads to an early (days 0-3) impairment of immune responsiveness followed, with continued exposures, by a form of adaptation to O3 that results in a re-establishment of the immune response. The effects of O3 exposure on the response to antigenic stimulation also depend on the time at which O3 exposure occurred. Whereas O3 exposure prior to immunization is without effect on the response to antigen, O3 exposure subsequent to immunization suppresses the response to antigen. Although most studies have focused on immune responses in the lung, numerous investigators have provided functional and anatomical evidence to support the hypothesis that O3 exposure can have profound effects on systemic immunity

1-Methyl-tryptophan synergizes with methotrexate to alleviate arthritis in a mouse model of arthritis.

Rheumatoid arthritis (RA) is an inflammatory autoimmune disease with no known cure. Current strategies to treat RA, including methotrexate (MTX), target the later inflammatory stage of disease. Recently, we showed that inhibiting indoleamine-2,3-dioxygenase (IDO) with 1-methyl-tryptophan (1MT) targets autoantibodies and cytokines that drive the initiation of the autoimmune response. Therefore, we hypothesized that combining 1MT with MTX would target both the initiation and chronic inflammatory phases of the autoimmune response and be an effective co-therapeutic strategy for arthritis. To test this, we used K/BxN mice, a pre-clinical model of arthritis that develops joint-specific inflammation with many characteristics of human RA. Mice were treated with 1MT, MTX, alone or in combination, and followed for arthritis, autoantibodies, and inflammatory cytokines. Both 1MT and MTX were able to partially inhibit arthritis when used individually; however, combining MTX + 1MT was significantly more effective than either treatment alone at delaying the onset and alleviating the severity of joint inflammation. We went on to show that combination of MTX + 1MT did not lower inflammatory cytokine or autoantibody levels, nor could the synergistic co-therapeutic effect be reversed by the adenosine receptor antagonist theophylline or be mimicked by inhibition of polyamine synthesis. However, supplementation with folinic acid did reverse the synergistic co-therapeutic effect, demonstrating that, in the K/BxN model, MTX synergizes with 1MT by blocking folate metabolism. These data suggest that pharmacological inhibition of IDO with 1MT is a potential candidate for use in combination with MTX to increase its efficacy in the treatment of RA