16 research outputs found

    Ethylene negatively regulates transcript abundance of ROP-GAP rheostat-encoding genes and affects apoplastic reactive oxygen species homeostasis in epicarps of cold stored apple fruits

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    Apple (Malus 7domestica Borkh) fruits are stored for long periods of time at low temperatures (1 \ub0C) leading to the occurrence of physiological disorders. 'Superficial scald' of Granny Smith apples, an economically important ethylene-dependent disorder, was used as a model to study relationships among ethylene action, the regulation of the ROP-GAP rheostat, and maintenance of H2O2 homeostasis in fruits during prolonged cold exposure. The ROP-GAP rheostat is a key module for adaptation to low oxygen in Arabidopsis through Respiratory Burst NADPH Oxidase Homologs (RBOH)-mediated and ROP GTPase-dependent regulation of reactive oxygen species (ROS) homeostasis. Here, it was shown that the transcriptional expression of several components of the apple ROP-GAP machinery, including genes encoding RBOHs, ROPs, and their ancillary proteins ROP-GEFs and ROP-GAPs, is coordinately and negatively regulated by ethylene in conjunction with the progressive impairment of apoplastic H2O2 homeostatic levels. RNA sequencing analyses showed that several components of the known ROP- and ROS-associated transcriptional networks are regulated along with the ROP-GAP rheostat in response to ethylene perception. These findings may extend the role of the ROP-GAP rheostat beyond hypoxic responses and suggest that it may be a functional regulatory node involved in the integration of ethylene and ROS signalling pathways in abiotic stress

    CCQM key comparison – organic solutions : CCQM-K47 volatile organic compounds in methanol. Final Report

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    At the October 2005 CCQM Organic Analysis Working Group Meeting (IRMM, Belgium), the decision was made to proceed with a Key Comparison study (CCQM-K47) addressing the calibration function for the determination of volatile organic compounds (VOCs) used for water quality monitoring. This was coordinated by CENAM and NIST. Benzene, o-xylene, m-xylene and p-xylene were chosen as representative VOCs. The solvent of choice was methanol. Key Comparison CCQM-K47 demonstrated the capabilities of participating NMIs to identify and measure the four target VOCs in a calibration solution using GC-based methods. The measurement challenges in CCQM-K47, such as avoiding volatility loss, achieving adequate chromatographic resolution and isolating potential interferences, are typical of those required for value-assigning volatile reference materials. Participants achieving comparable measurements for all four VOCs in this Key Comparison should be capable of providing reference materials and measurements for VOCs in solutions when present at concentration levels greater than 10 ”g/g.Fil: Pérez Urquiza, Melina. Centro Nacional de Metrología (CENAM); MéxicoFil: Maldonado Torres, Mauricio. Centro Nacional de Metrología (CENAM); MéxicoFil: Mitani, Yoshito. Centro Nacional de Metrología (CENAM); MéxicoFil: Schantz, Michele M. National Institute of Standards and Technology (NIST); ArgentinaFil: Duewer, David L. National Institute of Standards and Technology (NIST); ArgentinaFil: May, Wille E. National Institute of Standards and Technology (NIST); ArgentinaFil: Parris, Reenie M. National Institute of Standards and Technology (NIST); ArgentinaFil: Wise, Stephen A. National Institute of Standards and Technology (NIST); ArgentinaFil: Kaminski, Katja. Federal Institute for Materials Research and Testing (BAM); AlemaniaFil: Philipp, Rosemarie. Federal Institute for Materials Research and Testing (BAM); AlemaniaFil: Win, Tin. Federal Institute for Materials Research and Testing (BAM); AlemaniaFil: Rosso, Adriana. Instituto Nacional de Tecnología Industrial (INTI); ArgentinaFil: Kim, Dal Ho. Korea Research Institute of Standards and Science (KRISS); Corea del SurFil: Ishikawa, Keiichiro. National Metrology Institute of Japan (NMIJ); JapónFil: Krylov, A. I. D. I. Mendeleev Institute for Metrology (VNIIM); RusiaFil: Kustikov, Y. A. D. I. Mendeleev Institute for Metrology (VNIIM); RusiaFil: Baldan, Annarita. Van Swinden Laboratorium (VS); Países Bajo

    European project: Metrology for Chemical Pollutants in Air

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    The measurement of gaseous pollutants in air is a sensitive and priority issue that has a large impact on human health and environment. The European Directive on “Ambient air quality and cleaner air for Europe” (2008/50/EC) sets limit values and data quality objectives for the measurement in EU member states of air pollutants in ambient air. Although no harmonized legislation is currently present for the monitoring of indoor air, the concern on the exposure to indoor chemical pollutants is clearly increasing. The Joint Research Project MACPoll (Metrology for Chemical Pollutants in Air), running under the European Metrology Research Program, addresses the need to improve the metrological traceability and comparability of measurements using current air monitoring techniques and the need to set up a metrological bases for the new sensor technologies used in air quality applications

    A Technical Review of the Feasibility of Producing Certified Reference Materials for the Measurement of Gaseous Pollutants in Ambient Air

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    Within the frame of the EU sponsoredproject ‘Cermatair’ (CertifiedReference Materials for the Measurement of Gaseous Pollutants in Ambient Air, contract G6RD-CT-2001-00517) the feasibility of preparing andcertifying reference materials for the measurement of sulphur dioxide, nitrogen dioxide, carbon monoxide and benzene in ambient air was studied. The project focused on measurements at concentration levels corresponding to limit values given in EU Ambient Air Quality Directives andcovered reference materials for the reference methods specifiedin these Directives and for alternative methods based on diffusive sampling. State-of-the-art technologies for the production and certification of the reference materials were identified through literature surveys. Limited batches of reference materials were preparedand , wherever appropriate, testedfor homogeneity. The reference materials were subsequently tested in small-scale external verifications, performedby 2–4 laboratories other than the preparation laboratory, aimedat identifying possible discrepancies between concentration values from the preparation processes and experimental values. The results of these verifications revealedpossible mechanisms of certification (basedon preparation or measurements). The remaining materials were subjectedto a one-year stability study.JRC.H.4-Transport and air qualit

    Preparation and analysis of zero gases for the measurement of trace VOCs in air monitoring

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    Air quality observations are performed globally to monitor the status of the atmosphere and its level of pollution and to assess mitigation strategies. Regulations of air quality monitoring programmes in various countries demand high-precision measurements for harmful substances often at low trace concentrations. These requirements can only be achieved by using high-quality calibration gases including high-purity zero gas. For volatile organic compound (VOC) observations, zero gas is defined as being hydrocarbon-free and can be, for example, purified air, nitrogen or helium. It is essential for the characterisation of the measurement devices and procedures, for instrument operation as well as for calibrations. Two commercial and one self-built gas purifiers were tested for their VOC removal efficiency following a standardised procedure. The tested gas purifiers included one adsorption cartridge with an inorganic media and two types of metal catalysts. A large range of VOCs were investigated, including the most abundant species typically measured at air monitoring stations. Both catalysts were able to remove a large range of VOCs whilst the tested adsorption cartridge was not suitable to remove light compounds up to C4. Memory effects occurred for the adsorption cartridge when exposed to higher concentration. This study emphasises the importance of explicitly examining a gas purifier for its intended application before applying it in the field

    The BIOREMA project - Part 3: International interlaboratory comparison for bio-ethanol test methods

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    The main objective of the reference materials for biofuel specifications (BIOREMA) project is the development of two test materials (one bio-ethanol material and one biodiesel material) with well-established reference values. Of a series of three papers, this part describes the material preparation, homogeneity study, stability study, and characterisation of the bio-ethanol material. The test material thus obtained was used in an interlaboratory comparison (ILC) to assess current practices and comparability amongst laboratories providing bio-ethanol testing services. Only 13 participants provided data, resulting in a small dataset for evaluation. Further, it appeared that for a number of laboratories, there was not sufficient material for the determination of all requested parameters. In most cases, as far as the data permit, it can be concluded that the consensus values (based on participant’s results) are in good agreement with the reference or the BIOREMA values (obtained by NMIs participating in the project). For three parameters, namely ethanol content, water content, and density, there is good agreement between the reference and consensus values. For these parameters, the reproducibility standard deviation is close to, or even smaller than, the expanded uncertainty associated with the reference value. A number of parameters show very poor reproducibility, for example, pHe, electrolytic conductivity, and acidity. The same applies to sodium and copper content, which are very low and therefore challenging parameters to measure accurately. The results of the ILC underpin the need for certified reference materials and demonstrate the requirement for more robust quality control to improve the precision and trueness of the results from testing laboratories.JRC.D.2-Standards for Innovation and sustainable Developmen

    The BIOREMA project - Part 2: International interlaboratory comparison for biodiesel test methods

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    The results of an interlaboratory comparison, using various measurement methods to carry out biodiesel testing, are presented and the findings are discussed. The interlaboratory comparison was organised within the framework of an EU-funded project called BIOREMA. A general overview of the project and results of an interlaboratory comparison on bioethanol are published as Part 1 and 2 of this series of papers. In the study presented here, reference values, provided by national metrology institutes and expert laboratories, were used for evaluating the results. Consensus values, derived from the results of all participants, were used to assess any bias between the results from the national metrology institutes and testing laboratories. The emphasis in this interlaboratory comparison was not the performance rating of the individual laboratories, but recognising and interpreting differences caused by the measurement methods applied. For most biodiesel parameters, a good agreement of measurement results was found among different methods, and between the consensus and reference values. The study material was a rapeseed oil fatty acid methyl ester, for which it was demonstrated that it is feasible to prepare and characterise reference materials for biodiesel with well-established reference values for many parameters.JRC.D.2-Standards for Innovation and sustainable Developmen

    The BIOREMA project - Part 1: Towards international comparability for biofuel analysis

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    There is an increasing demand to accurately measure the quality of biofuel products (e.g. biodiesel and bio-ethanol). This demand is driven in Europe by directives promoting the use of renewable sources of energy and worldwide by national and international legislation setting out quality requirements for these fuels. Until now, there has been no international consensus on the minimum technical specifications to ensure biofuel quality. Furthermore, it is unclear which reference materials and measurement techniques are needed to provide the quality assurance and quality control framework to underpin these legislative requirements. As part of the European Commission’s 7th Framework Programme, the BIOREMA project (REference MAterials for BIOfuel specifications) demonstrated the feasibility of preparing biodiesel and bio-ethanol reference materials with reference values traceable to the international system of units for a range of parameters at levels relevant to technical specifications. However, the project concluded also that further research is needed to improve the current measurement capabilities for some parameters. Within the BIOREMA project, two global interlaboratory comparisons were carried out, using the biodiesel and bio-ethanol test materials prepared during the feasibility stage of the project, as well as two biodiesel standard reference materials from the National Institute of Standards and Technology (NIST, USA). The exercises showed that the measurement capabilities of the field laboratories were in many cases satisfactory, whereas for other laboratories the availability and regular use of certified reference materials would likely enhance the measurement capabilities for many of the parameters studied. A general overview of the BIOREMA project is presented in this paper. The details of the production of the two types of BIOREMA reference materials, and the results of the interlaboratory comparison for the bio-ethanol and biodiesel study materials, are discussed in parts 2 and 3 of this series of papers.JRC.D.2-Standards for Innovation and sustainable Developmen
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