The Tawawa Woods Natural Landmark: II. Plant Species Composition and Recovery from Disturbance

Author Institution: Department of Science and Mathematics, Cedarville University ; Department of Natural Sciences and Mathematics, Central State UniversityPortions of Tawawa Woods, an oak-maple-beech forest community adjacent to Wilberforce (Greene Co.), OH, was granted landmark status in 1990 on the basis of its biodiversity, historic and cultural significance, and its potential as a site for studies of forest recovery from disturbance. Earlier, in 1974, Tawawa Woods was partially destroyed by a tornado that swept through nearby Xenia and vicinity. In 1988 and in 1999, we conducted studies of the plant species composition of Tawawa Woods with emphasis on tree species abundance, age, spatial distribution, and relative dominance. We used both plot sampling and point-centered quarter sampling methods. Although a total of 27 tree species were included in the samples, in 1988, 80% of the relative density was contributed by only eight species; notably, Acer saccharum, Prunus serotina, Liriodendron tulipifera, Fagus grandifolia, Sassafras albidum, Fraxinus americana, Quercus rubra, and Quercus alba. Comparisons of tree species abundance, distribution, and dominance as a function of sampling date and tree age class are discussed with regard to forest recovery from disturbance during the past 11 years, with emphasis upon the increasing importance of Acer saccharum. A case is made for elevating the Tawawa Woods Natural Landmark to Natural Area status based upon its strategic location in the Massies Creek corridor, and its ecological and historical significance

Integrated Amplification Microarrays for Infectious Disease Diagnostics

This overview describes microarray-based tests that combine solution-phase amplification chemistry and microarray hybridization within a single microfluidic chamber. The integrated biochemical approach improves microarray workflow for diagnostic applications by reducing the number of steps and minimizing the potential for sample or amplicon cross-contamination. Examples described herein illustrate a basic, integrated approach for DNA and RNA genomes, and a simple consumable architecture for incorporating wash steps while retaining an entirely closed system. It is anticipated that integrated microarray biochemistry will provide an opportunity to significantly reduce the complexity and cost of microarray consumables, equipment, and workflow, which in turn will enable a broader spectrum of users to exploit the intrinsic multiplexing power of microarrays for infectious disease diagnostics

Genotyping Multidrug-Resistant Mycobacterium tuberculosis from Primary Sputum and Decontaminated Sediment with an Integrated Microfluidic Amplification Microarray Test

ABSTRACT There is a growing awareness that molecular diagnostics for detect-to-treat applications will soon need a highly multiplexed mutation detection and identification capability. In this study, we converted an open-amplicon microarray hybridization test for multidrug-resistant (MDR) Mycobacterium tuberculosis into an entirely closed-amplicon consumable (an amplification microarray) and evaluated its performance with matched sputum and sediment extracts. Reproducible genotyping (the limit of detection) was achieved with ∼25 M. tuberculosis genomes (100 fg of M. tuberculosis DNA) per reaction; the estimated shelf life of the test was at least 18 months when it was stored at 4°C. The test detected M. tuberculosis in 99.1% of sputum extracts and 100% of sediment extracts and showed 100% concordance with the results of real-time PCR. The levels of concordance between M. tuberculosis and resistance-associated gene detection were 99.1% and 98.4% for sputum and sediment extracts, respectively. Genotyping results were 100% concordant between sputum and sediment extracts. Relative to the results of culture-based drug susceptibility testing, the test was 97.1% specific and 75.0% sensitive for the detection of rifampin resistance in both sputum and sediment extracts. The specificity for the detection of isoniazid (INH) resistance was 98.4% and 96.8% for sputum and sediment extracts, respectively, and the sensitivity for the detection of INH resistance was 63.6%. The amplification microarray reported the correct genotype for all discordant phenotype/genotype results. On the basis of these data, primary sputum may be considered a preferred specimen for the test. The amplification microarray design, shelf life, and analytical performance metrics are well aligned with consensus product profiles for next-generation drug-resistant M. tuberculosis diagnostics and represent a significant ease-of-use advantage over other hybridization-based tests for diagnosing MDR tuberculosis