Parallel computing in information retrieval - An updated review

The progress of parallel computing in Information Retrieval (IR) is reviewed. In particular we stress the importance of the motivation in using parallel computing for Text Retrieval. We analyse parallel IR systems using a classification due to Rasmussen [1] and describe some parallel IR systems. We give a description of the retrieval models used in parallel Information Processing.. We describe areas of research which we believe are needed

Rhizobia inoculants containing synthetic Lipo-chitin oligosaccharides, LCO (Rhizobia signal molecules) improves pea plant establishment, vigor, and yield

Non-Peer Reviewe

Developing an instrument to quantify aerosol toxicity

Large-scale epidemiological studies have consistently shown that exposure to ambient particulate matter (PM) is responsible for a variety of adverse health effects. However, the specific physical and chemical properties of particles that are responsible for observed health effects, as well as the underlying mechanisms of particle toxicity upon exposure, remain largely uncertain. Studies have widely suggested that the oxidative potential (OP) of aerosol particles is a key metric to quantify particle toxicity. OP is defined as the ability of aerosol particle components to produce reactive oxidative species (ROS) and deplete antioxidants in vivo. Traditional methods for measuring OP using acellular assays largely rely on analyzing PM collected in filters offline. This is labor intensive and involves a substantial time delay between particle collection and OP analysis. It therefore likely underestimates particle OP, because many reactive chemical components which are contributing to OP are short-lived and therefore degrade prior to offline analysis. We investigated these differences in online and offline measurements with different acellular assays and with cellular methods and could show that for biogenic secondary organic aerosol (SOA), a large fraction decays within minutes to hours. Thus, new techniques are required to provide a robust and rapid quantification of particle OP, capturing the chemistry of oxidizing and short-lived highly reactive aerosol components and their concentration dynamics in the atmosphere. To address these measurement shortcomings, we developed a portable online instrument that directly samples particles into an ascorbic acid-based assay under physiologically relevant conditions of pH 6.8 and 37 °C, providing continuous accurate OP measurements with a high time resolution (5 min). This online oxidative potential ascorbic acid instrument (OOPAAI) runs autonomously for up to three days and has a detection limit of about 5 μg/m3 in an urban environ- ment, which allows the characterization of particle OP, even in low-pollution areas. With this novel instrument, we not only measured ambient aerosol, but also conducted various laboratory campaigns where we investigated the toxicity of various aerosol systems. Primary and secondary emissions with different aging times from car exhaust were measured and compared to primary and secondary aerosols from residential wood combustion, showing a higher toxicity for residential wood combustion for primary and secondary aerosols. Furthermore, we investigated the influence of transition metals like copper and iron on the OP of secondary organic aerosol. We could show that there is a synergistic effect for biogenic SOA with copper and for anthropogenic SOA with copper and iron, but an antagonistic effect with iron and biogenic SOA measured with the OOPAAI