982 research outputs found

    Hunter Activities, Conflicts, and Opinions Following Implementation of a Controlled Waterfowl Hunting Program on the Rend Lake Public Hunting Area in 1995-96

    Get PDF
    Waterfowl Program Periodic Report no. 90Report issued on: 2 December 199

    Topographic Evolution in the Atomic Scale Growth and Erosion Continuum

    Get PDF
    This review gives a detailed survey of the range of fascinating surface features which develop under growth or erosion conditions under the combined influence of thermal and more energetic atomic particle fluxes. Collisionally induced atomic ejection and migration, and thermally and radiation induced atom and defect diffusion processes are outlined and their relevance to topographic initiation and evolution explored. A range of experimental observations of surface feature elaboration is discussed from net growth to net erosion conditions and models for their explanation are considered. It is concluded that while much data have been accumulated, much of these have been in so diverse experimental conditions that precise modelling in atomic terms is difficult and generalisations are treacherous. A clear need for structured, extensive studies exists with very precise parameter definition and control

    Seasonal phosphate activity in three characteristic soils of the English uplands polluted by long-term atmospheric nitrogen deposition

    Get PDF
    Phosphomonoesterase activities were determined monthly during a seasonal cycle in three characteristic soil types of the English uplands that have been subject to long-term atmospheric nitrogen deposition. Activities (moll para-nitrophenol ri soil dry wt. h-1) ranged between 83.9 and 307 in a blanket peat (total carbon 318 mg g-1, pH 3.9), 45.2-86.4 in an acid organic grassland soil (total carbon 354 mg g-1, pH 3.7) and 10.4-21.1 in a calcareous grassland soil (total carbon 140 mg g-1, pH 7.3). These are amongst the highest reported soil phosphomonoesterase activities and confirm the strong biological phosphorus limitation in this environmen

    Operon conservation and the evolution of trans-splicing in the phylum Nematoda

    Get PDF
    The nematode Caenorhabditis elegans is unique among model animals in that many of its genes are cotranscribed as polycistronic pre-mRNAs from operons. The mechanism by which these operonic transcripts are resolved into mature mRNAs includes trans-splicing to a family of SL2-like spliced leader exons. SL2-like spliced leaders are distinct from SL1, the major spliced leader in C. elegans and other nematode species. We surveyed five additional nematode species, representing three of the five major clades of the phylum Nematoda, for the presence of operons and the use of trans-spliced leaders in resolution of polycistronic pre-mRNAs. Conserved operons were found in Pristionchus pacificus, Nippostrongylus brasiliensis, Strongyloides ratti, Brugia malayi, and Ascaris suum. In nematodes closely related to the rhabditine C. elegans, a related family of SL2-like spliced leaders is used for operonic transcript resolution. However, in the tylenchine S. ratti operonic transcripts are resolved using a family of spliced leaders related to SL1. Non-operonic genes in S. ratti may also receive these SL1 variants. In the spirurine nematodes B. malayi and A. suum operonic transcripts are resolved using SL1. Mapping these phenotypes onto the robust molecular phylogeny for the Nematoda suggests that operons evolved before SL2-like spliced leaders, which are an evolutionary invention of the rhabditine lineage

    Serverā€side workflow execution using data grid technology for reproducible analyses of dataā€intensive hydrologic systems

    Get PDF
    Many geoscience disciplines utilize complex computational models for advancing understanding and sustainable management of Earth systems. Executing such models and their associated data preprocessing and postprocessing routines can be challenging for a number of reasons including (1) accessing and preprocessing the large volume and variety of data required by the model, (2) postprocessing large data collections generated by the model, and (3) orchestrating data processing tools, each with unique software dependencies, into workflows that can be easily reproduced and reused. To address these challenges, the work reported in this paper leverages the Workflow Structured Object functionality of the Integrated Ruleā€Oriented Data System and demonstrates how it can be used to access distributed data, encapsulate hydrologic data processing as workflows, and federate with other communityā€driven cyberinfrastructure systems. The approach is demonstrated for a study investigating the impact of drought on populations in the Carolinas region of the United States. The analysis leverages computational modeling along with data from the Terra Populus project and data management and publication services provided by the Sustainable Environmentā€Actionable Data project. The work is part of a larger effort under the DataNet Federation Consortium project that aims to demonstrate data and computational interoperability across cyberinfrastructure developed independently by scientific communities.Plain Language SummaryExecuting computational workflows in the geosciences can be challenging, especially when dealing with large, distributed, and heterogeneous data sets and computational tools. We present a methodology for addressing this challenge using the Integrated Ruleā€Oriented Data System (iRODS) Workflow Structured Object (WSO). We demonstrate the approach through an endā€toā€end application of data access, processing, and publication of digital assets for a scientific study analyzing drought in the Carolinas region of the United States.Key PointsReproducibility of dataā€intensive analyses remains a significant challengeData grids are useful for reproducibility of workflows requiring large, distributed data setsData and computations should be coā€located on servers to create executable Webā€resourcesPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137520/1/ess271_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137520/2/ess271.pd
    • ā€¦
    corecore