331 research outputs found

    Fourth Annual Report: 2007 Pre-Construction Eelgrass Monitoring and Propagation for King County Outfall Mitigation

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    King County proposes to build a new sewer outfall discharging to Puget Sound near Point Wells, Washington. Construction is scheduled for 2008. The Point Wells site was selected to minimize effects on the nearshore marine environment, but unavoidable impacts to eelgrass (Zostera marina) beds are anticipated during construction. To mitigate these impacts and prepare for post-construction restoration, King County began implementing a multiyear eelgrass monitoring and restoration program in 2004, with the primary goal of returning intertidal and shallow subtidal habitat and eelgrass to pre-construction conditions. Major program elements related to eelgrass are (a) pre-construction monitoring, i.e., documenting initial eelgrass conditions and degree of fluctuation over 5 years prior to construction, (b) eelgrass transplanting, including harvesting, offsite propagating, and stockpiling of local plants for post-construction planting, and (c) post-construction planting and subsequent monitoring. The program is detailed in the Eelgrass Restoration and Biological Resources Implementation Workplan (King County 2006). This report describes calendar year 2007 pre-construction activities conducted by Pacific Northwest National Laboratory (PNNL) for King County. Activities included continued propagation of eelgrass shoots at the PNNL Marine Sciences Laboratory (MSL) in Sequim, Washington, and monitoring of the experimental harvest plots in the marine outfall corridor area to evaluate recovery rates relative to harvest rates. In addition, 490 eelgrass shoots were also harvested from the Marine Outfall Corridor in July 2007 to supplement the plants in the propagation tank at the MSL, bringing the total number of shoots to 1464. Eelgrass densities were monitored in four of five experimental harvest plots established in the Marine Outfall Corridor. Changes in eelgrass density were evaluated in year-to-year comparisons with initial harvest rates. A net increase in eelgrass density from 2004 post-harvest to 2007 was observed in all plots, despite density decreases observed in 2006 in all plots and at most harvest rates. Eelgrass densities within individual subplots were highly variable from year to year, and the change in density in any interannual period was not related to initial 2004 harvest rate. Harvest rates of neighboring subplots did not appear to affect subplot eelgrass density (Woodruff et al. 2007). Three years post-harvest, eelgrass shoot densities were not significantly different from pre-harvest shoot densities at any harvest level. Additional plans are being discussed with King County to harvest all eelgrass from the construction corridor and hold in the propagation tanks at the MSL for post-construction planting. Under this plan, plants that would have been lost to construction will be held offsite until construction is completed. This strategy reduces and possibly eliminates the need to harvest eelgrass from donor beds located south of the construction area, allowing them to remain undisturbed. However, if eelgrass is harvested from donor beds, the monitoring of eelgrass growth at different harvest rates should help determine an optimum harvest rate that supports rapid recovery of donor eelgrass beds

    Topological organization of whole-brain white matter in HIV infection

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    Infection with human immunodeficiency virus (HIV) is associated with neuroimaging alterations. However, little is known about the topological organization of whole-brain networks and the corresponding association with cognition. As such, we examined structural whole-brain white matter connectivity patterns and cognitive performance in 29 HIV+ young adults (mean age = 25.9) with limited or no HIV treatment history. HIV+ participants and demographically similar HIV− controls (n = 16) residing in South Africa underwent magnetic resonance imaging (MRI) and neuropsychological testing. Structural network models were constructed using diffusion MRI-based multifiber tractography and T(1)-weighted MRI-based regional gray matter segmentation. Global network measures included whole-brain structural integration, connection strength, and structural segregation. Cognition was measured using a neuropsychological global deficit score (GDS) as well as individual cognitive domains. Results revealed that HIV+ participants exhibited significant disruptions to whole-brain networks, characterized by weaker structural integration (characteristic path length and efficiency), connection strength, and structural segregation (clustering coefficient) than HIV− controls (p < 0.05). GDSs and performance on learning/recall tasks were negatively correlated with the clustering coefficient (p < 0.05) in HIV+ participants. Results from this study indicate disruption to brain network integrity in treatment-limited HIV+ young adults with corresponding abnormalities in cognitive performance

    Efficient Transfer Doping of Carbon Nanotube Forests by MoO3.

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    We dope nanotube forests using evaporated MoO3 and observe the forest resistivity to decrease by 2 orders of magnitude, reaching values as low as ∼5 × 10(-5) Ωcm, thus approaching that of copper. Using in situ photoemission spectroscopy, we determine the minimum necessary MoO3 thickness to dope a forest and study the underlying doping mechanism. Homogenous coating and tube compaction emerge as key factors for decreasing the forest resistivity. When all nanotubes are fully coated with MoO3 and packed, conduction channels are created both inside the nanotubes and on the outside oxide layer. This is supported by density functional theory calculations, which show a shift of the Fermi energy of the nanotubes and the conversion of the oxide into a layer of metallic character. MoO3 doping removes the need for chirality control during nanotube growth and represents a step forward toward the use of forests in next-generation electronics and in power cables or conductive polymers.The authors acknowledge financial support from European project Grafol.This is the accepted manuscript. The final version is available at http://pubs.acs.org/doi/full/10.1021/acsnano.5b04644

    Botulism Type E Outbreak Associated with Eating a Beached Whale, Alaska

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    We report an outbreak of botulism that occurred in July 2002 in a group of 12 Alaskan Yu'pik Eskimos who ate blubber and skin from a beached beluga whale. Botulism death rates among Alaska Natives have declined in the last 20 years, yet incidence has increased

    The C5a anaphylatoxin receptor CD88 is expressed in presynaptic terminals of hippocampal mossy fibres

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    Background: In the periphery, C5a acts through the G-protein coupled receptor CD88 to enhance/maintain inflammatory responses. In the brain, CD88 can be expressed on astrocytes, microglia and neurons. Previous studies have shown that the hippocampal CA3 region displays CD88-immunolabelling, and CD88 mRNA is present within dentate gyrus granule cells. As granule cells send dense axonal projections (mossy fibres) to CA3 pyramidal neurons, CD88 expression could be expressed on mossy fibres. However, the cellular location of CD88 within the hippocampal CA3 region is unknown

    Simple Viscous Flows: from Boundary Layers to the Renormalization Group

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    The seemingly simple problem of determining the drag on a body moving through a very viscous fluid has, for over 150 years, been a source of theoretical confusion, mathematical paradoxes, and experimental artifacts, primarily arising from the complex boundary layer structure of the flow near the body and at infinity. We review the extensive experimental and theoretical literature on this problem, with special emphasis on the logical relationship between different approaches. The survey begins with the developments of matched asymptotic expansions, and concludes with a discussion of perturbative renormalization group techniques, adapted from quantum field theory to differential equations. The renormalization group calculations lead to a new prediction for the drag coefficient, one which can both reproduce and surpass the results of matched asymptotics

    SPIROMICS Protocol for Multicenter Quantitative Computed Tomography to Phenotype the Lungs

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    Multidetector row computed tomography (MDCT) is increasingly taking a central role in identifying subphenotypes within chronic obstructive pulmonary disease (COPD), asthma, and other lung-related disease populations, allowing for the quantification of the amount and distribution of altered parenchyma along with the characterization of airway and vascular anatomy. The embedding of quantitative CT (QCT) into a multicenter trial with a variety of scanner makes and models along with the variety of pressures within a clinical radiology setting has proven challenging, especially in the context of a longitudinal study. SPIROMICS (Subpopulations and Intermediate Outcome Measures in COPD Study), sponsored by the National Institutes of Health, has established a QCT lung assessment system (QCT-LAS), which includes scanner-specific imaging protocols for lung assessment at total lung capacity and residual volume. Also included are monthly scanning of a standardized test object and web-based tools for subject registration, protocol assignment, and data transmission coupled with automated image interrogation to assure protocol adherence. The SPIROMICS QCT-LAS has been adopted and contributed to by a growing number of other multicenter studies in which imaging is embedded. The key components of the SPIROMICS QCT-LAS along with evidence of implementation success are described herein. While imaging technologies continue to evolve, the required components of a QCT-LAS provide the framework for future studies, and the QCT results emanating from SPIROMICS and the growing number of other studies using the SPIROMICS QCT-LAS will provide a shared resource of image-derived pulmonary metrics
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