Quantification of Rare Earth Elements in the Parts Per Million Range: A Novel Approach in the Application of Laser-Induced Breakdown Spectroscopy.

This work extends a previous percentage level concentration study of the optical emission spectra for six rare earth elements, europium (Eu), gadolinium (Gd), lanthanum (La), praseodymium (Pr), neodymium (Nd), and samarium (Sm), along with the transition metal, yttrium (Y) using laser-induced breakdown spectroscopy (LIBS). The concentration of these six rare earth elements and yttrium has been attempted for the first time systematically down to parts per million (ppm) concentration levels ranging from 30 to 300 ppm. The authors have developed multivariate models for each element capable of predicting concentration with acceptable to excellent levels of accuracy.

Enrichment of Root Endophytic Bacteria from Populus deltoides and Single-Cell-Genomics Analysis.

Unlabelled: Bacterial endophytes that colonize Populus trees contribute to nutrient acquisition, prime immunity responses, and directly or indirectly increase both above- and below-ground biomasses. Endophytes are embedded within plant material, so physical separation and isolation are difficult tasks. Application of culture-independent methods, such as metagenome or bacterial transcriptome sequencing, has been limited due to the predominance of DNA from the plant biomass.

Multiple single-cell genomes provide insight into functions of uncultured Deltaproteobacteria in the human oral cavity.

Despite a long history of investigation, many bacteria associated with the human oral cavity have yet to be cultured. Studies that correlate the presence or abundance of uncultured species with oral health or disease highlight the importance of these community members. Thus, we sequenced several single-cell genomic amplicons from Desulfobulbus and Desulfovibrio (class Deltaproteobacteria) to better understand their function within the human oral community and their association with periodontitis, as well as other systemic diseases.

Anaerobic high-throughput cultivation method for isolation of thermophiles using biomass-derived substrates.

Flow cytometry (FCM) techniques have been developed for sorting mesophilic organisms, but the difficulty increases if the target microbes are thermophilic anaerobes. We demonstrate a reliable, high-throughput method of screening thermophilic anaerobic organisms using FCM and 96-well plates for growth on biomass-relevant substrates. The method was tested using the cellulolytic thermophiles Clostridium thermocellum (T(opt) = 55 °C), Caldicellulosiruptor obsidiansis (T(opt) = 78 °C) and the fermentative hyperthermophiles, Pyrococcus furiosus (T(opt) = 100 °C) and Thermotoga maritima (T(opt) = 80 °C).

Improved measurement for volatile particles: vapor-particle separator design and laboratory tests.

Sampling and measurement of volatile particles is a challenging task. It has been hampered by lack of a reliable technique capable of accurately capturing the phase-partition process of the pollutants without generating bias and artifacts in the data. The objective of this research is to design a new vapor-particle separation technique for performing the phase separation on-line (the sampling aspect), which, simultaneously, enables characterization of the vapors and particles.

Caldicellulosiruptor obsidiansis sp. nov., an anaerobic, extremely thermophilic, cellulolytic bacterium isolated from Obsidian Pool, Yellowstone National Park.

A novel, obligately anaerobic, extremely thermophilic, cellulolytic bacterium, designated OB47(T), was isolated from Obsidian Pool, Yellowstone National Park, WY. The isolate was a nonmotile, non-spore-forming, Gram-positive rod approximately 2 microm long by 0.2 microm wide and grew at temperatures between 55 and 85 degrees C, with the optimum at 78 degrees C.

Miniature sensor suitable for electronic nose applications.

A major research effort has been devoted over the years for the development of chemical sensors for the detection of chemical and explosive vapors. However, the deployment of such chemical sensors will require the use of multiple sensors (probably tens of sensors) in a sensor package to achieve selective detection. In order to keep the overall detector unit small, miniature sensors with sufficient sensitivity of detection will be needed.