532 research outputs found

    Methylation array data can simultaneously identify individuals and convey protected health information: an unrecognized ethical concern

    Get PDF
    BACKGROUND: Genome-wide methylation arrays are increasingly used tools in studies of complex medical disorders. Because of their expense and potential utility to the scientific community, current federal policy dictates that data from these arrays, like those from genome-wide genotyping arrays, be deposited in publicly available databases. Unlike the genotyping information, access to the expression data is not restricted. An underlying supposition in the current nonrestricted access to methylation data is the belief that protected health and personal identifying information cannot be simultaneously extracted from these arrays. RESULTS: In this communication, we analyze methylation data from the Illumina HumanMethylation450 array and show that genotype at 1,069 highly informative loci, and both alcohol and smoking consumption information, can be derived from the array data. CONCLUSIONS: We conclude that both potentially personally identifying information and substance-use histories can be simultaneously derived from methylation array data. Because access to genetic information about a database subject or one of their relatives is critical to the de-identification process, this risk of de-identification is limited at the current time. We propose that access to genome-wide methylation data be restricted to institutionally approved investigators who accede to data use agreements prohibiting re-identification

    Increasing biomass in Amazonian forest plots

    Get PDF
    A previous study by Phillips et al. of changes in the biomass of permanent sample plots in Amazonian forests was used to infer the presence of a regional carbon sink. However, these results generated a vigorous debate about sampling and methodological issues. Therefore we present a new analysis of biomass change in old-growth Amazonian forest plots using updated inventory data. We find that across 59 sites, the above-ground dry biomass in trees that are more than 10 cm in diameter (AGB) has increased since plot establishment by 1.22 ± 0.43 Mg per hectare per year (ha-1 yr-1), where 1 ha = 104 m2), or 0.98 ± 0.38 Mg ha-1 yr-1 if individual plot values are weighted by the number of hectare years of monitoring. This significant increase is neither confounded by spatial or temporal variation in wood specific gravity, nor dependent on the allometric equation used to estimate AGB. The conclusion is also robust to uncertainty about diameter measurements for problematic trees: for 34 plots in western Amazon forests a significant increase in AGB is found even with a conservative assumption of zero growth for all trees where diameter measurements were made using optical methods and/or growth rates needed to be estimated following fieldwork. Overall, our results suggest a slightly greater rate of net stand-level change than was reported by Phillips et al. Considering the spatial and temporal scale of sampling and associated studies showing increases in forest growth and stem turnover, the results presented here suggest that the total biomass of these plots has on average increased and that there has been a regional-scale carbon sink in old-growth Amazonian forests during the previous two decades

    Increasing dominance of large lianas in Amazonian forests

    Get PDF
    Ecological orthodoxy suggests that old-growth forests should be close to dynamic equilibrium, but this view has been challenged by recent findings that neotropical forests are accumulating carbon and biomass, possibly in response to the increasing atmospheric concentrations of carbon dioxide. However, it is unclear whether the recent increase in tree biomass has been accompanied by a shift in community composition. Such changes could reduce or enhance the carbon storage potential of old-growth forests in the long term. Here we show that non-fragmented Amazon forests are experiencing a concerted increase in the density, basal area and mean size of woody climbing plants (lianas). Over the last two decades of the twentieth century the dominance of large lianas relative to trees has increased by 1.7–4.6% a year. Lianas enhance tree mortality and suppress tree growth, so their rapid increase implies that the tropical terrestrial carbon sink may shut down sooner than current models suggest. Predictions of future tropical carbon fluxes will need to account for the changing composition and dynamics of supposedly undisturbed forests

    ZooKeys, unlocking Earth's incredible biodiversity and building a sustainable bridge into the public domain: From "print-based" to "web-based" taxonomy, systematics, and natural history.

    Get PDF
    Publishing taxonomic and systematics studies in the digital era faces major challenges and requires new approaches, many of which are currently stimulating spirited discussions amongst taxonomists and systematists. New amendments to the International Code of Zoological Nomenclature are expected to regulate electronic publishing of new taxa and create a standard form for their registration (ZooBank). Responding to a perceived need, this editorial announces establishment of ZooKeys – a new online and print journal in zoological taxonomy and systematics, which aims to quickly respond and adapt to the newest developments in taxonomic publishing. Open Access is accepted as mandatory for ZooKeys. The rationale for and concept of ZooKeys is discussed in detail

    Design for ground beetle abundance and diversity sampling within the National Ecological Observatory Network

    Get PDF
    The National Ecological Observatory Network (NEON) will monitor ground beetle populations across a network of broadly distributed sites because beetles are prevalent in food webs, are sensitive to abiotic factors, and have an established role as indicator species of habitat and climatic shifts. We describe the design of ground beetle population sampling in the context of NEON's long-term, continentalscale monitoring program, emphasizing the sampling design, priorities, and collection methods. Freely available NEON ground beetle data and associated field and laboratory samples will increase scientific understanding of how biological communities are responding to land-use and climate change.Peer reviewe

    The HST/ACS Coma Cluster Survey. II. Data Description and Source Catalogs

    Full text link
    The Coma cluster was the target of a HST-ACS Treasury program designed for deep imaging in the F475W and F814W passbands. Although our survey was interrupted by the ACS instrument failure in 2007, the partially completed survey still covers ~50% of the core high-density region in Coma. Observations were performed for 25 fields that extend over a wide range of cluster-centric radii (~1.75 Mpc) with a total coverage area of 274 arcmin^2. The majority of the fields are located near the core region of Coma (19/25 pointings) with six additional fields in the south-west region of the cluster. In this paper we present reprocessed images and SExtractor source catalogs for our survey fields, including a detailed description of the methodology used for object detection and photometry, the subtraction of bright galaxies to measure faint underlying objects, and the use of simulations to assess the photometric accuracy and completeness of our catalogs. We also use simulations to perform aperture corrections for the SExtractor Kron magnitudes based only on the measured source flux and half-light radius. We have performed photometry for ~73,000 unique objects; one-half of our detections are brighter than the 10-sigma point-source detection limit at F814W=25.8 mag (AB). The slight majority of objects (60%) are unresolved or only marginally resolved by ACS. We estimate that Coma members are 5-10% of all source detections, which consist of a large population of unresolved objects (primarily GCs but also UCDs) and a wide variety of extended galaxies from a cD galaxy to dwarf LSB galaxies. The red sequence of Coma member galaxies has a constant slope and dispersion across 9 magnitudes (-21<M_F814W<-13). The initial data release for the HST-ACS Coma Treasury program was made available to the public in 2008 August. The images and catalogs described in this study relate to our second data release.Comment: Accepted for publication in ApJS. A high-resolution version is available at http://archdev.stsci.edu/pub/hlsp/coma/release2/PaperII.pd

    Do Option Markets Substitute for Stock Markets?

    Get PDF
    Using a sample of cash tender offers occurring between 1993 and 2002, we find evidence that the options market has become the preferred venue for traders attempting to profit on anticipated announcements. Options offer advantages relative to stocks. Traders gain leverage by trading in options and multiple options contracts on an individual stock. The results of our study indicate that a substitution effect does exist. Abnormal volume in the option market replaces abnormal volume in the stock market prior to cash tender offer announcements, and this abnormal option volume precedes abnormal stock volume for targets with or without traded options
    corecore