2,035 research outputs found

    Evaluation of the Private Forestland Ownership Paracelization and its effects on the forest landscape in the southeastern Missouri Ozarks

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    The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file viewed on (November 8, 2006)Includes bibliographical references.Vita.Thesis (Ph. D.) University of Missouri-Columbia 2005.Dissertations, Academic -- University of Missouri--Columbia -- Forestry.This study investigates the impacts of the forestland ownership parcelization on species composition, age structure and spatial pattern of the forest landscape. First, a computer model was developed to create ownership patterns characterized by the actual shape and size. Model is validated and applied to simulate ownership patterns with various parcelization levels. Second, a transition matrix model is used to characterize the changes in forestland ownership parcelization. Results suggest a strong tendency towards further parcelization, characterized by parcel size classes smaller than 100 ha, and reveals the contributions from purchases by the Pioneer Forest. Third, the harvest regimes in a parcelized ownership landscape is spatially implemented for a forest landscape model --LANDIS -- to evaluate their effects on forest composition, age structure, and spatial pattern. Results suggest that changes will be dominated by the successional process, with significant but limited effects from parcelization levels and harvest intensities

    (S)-[5-Methyl-3-(3-methyl­thio­phen-2-yl)-4,5-dihydro­isoxazol-5-yl]methanol

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    In the title compound, C10H13NO2S, the thio­phene and isoxazoline rings are almost coplanar, the dihedral angle between their least-squares planes being 2.08 (1)°. The O—H atoms of the methyl hy­droxy group and the N atom of the isoxazole ring are orientated in the same direction to allow for the formation of inter­molecular O—H⋯N hydrogen bonds that lead to a supra­molecular chain along the a axis

    Internal evaluation of a physically-based distributed model using data from a Mediterranean mountain catchment

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    An evaluation of the performance of a physically-based distributed model of a small Mediterennean mountain catchment is presented. This was carried out using hydrological response data, including measurements of runoff, soil moisture, phreactic surface level and actual evapotranspiration. A-priori model parameterisation was based as far as possible on property data measured in the catchment. Limited model calibration was required to identify an appropriate value for terms controlling water loss to a deeper regional aquifer. The model provided good results for an initial calibration period, when judge in terms of catchment discharge. However, model performance for runoff declined substantially when evaluated againts a consecutive, rather drier, period of data. Evaluation against other catchment responses allowed identification of the problems responsible for the observed lack of model robustness in flow simulation. In particular, it was shown that an incorrect parameterisation of the soil water was preventing adequate representation of drainage from soils during hydrogeraph recessions. This excess moisture was then being removed via an overestimation of evapotranspiration. It also appeared that the model underestimated canopy interception. The results presented here suggest that model evaluation against catchment scale variables summarising its water balance can be of great use in identifying problems with model parameterisation, even for distributed models. Evaluation using spatially distributed data yielded less useful information on model performance, owing to the relative sparseness of data points, and problems of mismatch of scale between the measurement and the model grid.This work was carried out as part of project VAHMPIRE (Validating Hydrological Models using Process Studies and Internal Data from Research Basins: tools for assessing the hydrological impacts of environmental change), which was funded by the European Commission Framework IV Environment and Climate Program (Contract No. ENV4- CT95-0134). Simulations were carried out on a UNIX workstation funded jointly by UK Nirex Ltd. and NERC grant GR3/ E0009.Peer Reviewe

    High-Performance Screen-Printed Thermoelectric Films on Fabrics.

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    Printing techniques could offer a scalable approach to fabricate thermoelectric (TE) devices on flexible substrates for power generation used in wearable devices and personalized thermo-regulation. However, typical printing processes need a large concentration of binder additives, which often render a detrimental effect on electrical transport of the printed TE layers. Here, we report scalable screen-printing of TE layers on flexible fiber glass fabrics, by rationally optimizing the printing inks consisting of TE particles (p-type Bi0.5Sb1.5Te3 or n-type Bi2Te2.7Se0.3), binders, and organic solvents. We identified a suitable binder additive, methyl cellulose, which offers suitable viscosity for printability at a very small concentration (0.45-0.60 wt.%), thus minimizing its negative impact on electrical transport. Following printing, the binders were subsequently burnt off via sintering and hot pressing. We found that the nanoscale defects left behind after the binder burnt off became effective phonon scattering centers, leading to low lattice thermal conductivity in the printed n-type material. With the high electrical conductivity and low thermal conductivity, the screen-printed TE layers showed high room-temperature ZT values of 0.65 and 0.81 for p-type and n-type, respectively

    Two-Step Generation of Oligodendrocyte Progenitor Cells From Mouse Fibroblasts for Spinal Cord Injury

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    Oligodendrocyte progenitor cells (OPCs) are attracting attention as the ideal cell therapy for spinal cord injury (SCI). Recently, advanced reprogramming and differentiation techniques have made it possible to generate therapeutic cells for treating SCI. In the present study, we used directly-induced neural stem cells (DNSCs) from fibroblasts to establish OPCs (DN-OPCs) capable of proliferation and confirmed their OPC-specific characteristics. Also, we evaluated the effect of transplanted DN-OPCs on SCI in rats. The DN-OPCs exhibited an OPC-specific phenotype and electrophysiological function and could be differentiated into oligodendrocytes. In the SCI model, transplanted DN-OPCs improved behavior recovery, and showed engraftment into the host spinal cord with expression of myelin basic protein. These results suggest that DN-OPCs could be a new source of potentially useful cells for treating SCI

    Epiblast Stem Cell Subpopulations Represent Mouse Embryos of Distinct Pregastrulation Stages

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    SummaryEmbryonic stem cells (ESCs) comprise at least two populations of cells with divergent states of pluripotency. Here, we show that epiblast stem cells (EpiSCs) also comprise two distinct cell populations that can be distinguished by the expression of a specific Oct4-GFP marker. These two subpopulations, Oct4-GFP positive and negative EpiSCs, are capable of converting into each other in vitro. Oct4-GFP positive and negative EpiSCs are distinct from ESCs with respect to global gene expression pattern, epigenetic profile, and Oct4 enhancer utilization. Oct4-GFP negative cells share features with cells of the late mouse epiblast and cannot form chimeras. However, Oct4-GFP positive EpiSCs, which only represent a minor EpiSC fraction, resemble cells of the early epiblast and can readily contribute to chimeras. Our findings suggest that the rare ability of EpiSCs to contribute to chimeras is due to the presence of the minor EpiSC fraction representing the early epiblast
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