156 research outputs found

    Landsat analysis of the dynamics of the Chesapeake Bay plume on the continental shelf

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    The dynamics of the Chesapeake Bay plume have been studied by examination of 81 dates of Landsat images with color additive enhancement and single-band density slicing. The plume was interpreted from surface turbidity discontinuties as revealed in images from multispectral scanner (MSS) bands 4-7. Results show that the Chesapeake Bay plume usually frequents the Virginia coast south of the Bay mouth. Wind and tide vectors are the principal variables affecting the plume dynamics. Southwestern (compared to northern) winds spread and disperse the plume easterly over a large area. Ebb tide images (compared to flood tide images) show a more dispersed plume. Flooding waters produce high turbidity levels over the shallow northern portion of the Bay mouth

    Applications of remote sensing to estuarine management : Final report and annual report number 7

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    Remote sensing techniques have been applied to problems in estuarine management in the seventh and final year of a NASA grant. A chromaticity technique for multi-date Landsat measurement of suspended sediment has been verified and made operational, and applied to sedimentation analysis of the ·Bay of Fundy Tidal Power Project. Dye-buoy photogrannnetry has been used to measure currents at depth and analyze suspended sediment plumes from hydraulic · dredging. Wetland permit sites and beach erosion site\u27s have been evaluated with aerial photography. Submerged aquatic vegetation has been mapped with tide- and wind-synchronized color photography. Virginia state resource monitoring needs have led to implementation of Landsat data p.rocessing capability for joint work with NASA Goddard on demonstration projects. This final report contains summaries and tables of the projects and activities of the Remote Sensing Center over the past seven years

    Chesapeake Bay Plume Dynamics from LANDSAT

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    Examination of 81 dates of Landsat images with enhancement and density slicing has shown that the Chesapeake Bay plume usually frequents the Virginia coast south of the Bay mouth. Southwestern (compared to northern) winds spread the plume easterly over a large area. Ebb tide images (compared to flood tide images) show a more dispersed plume. Flooding waters produce high turbidity levels over the shallow northern portion of the Bay mouth.https://scholarworks.wm.edu/vimsbooks/1129/thumbnail.jp

    Seasat SAR test of the Virginian Sea Wave Climate Model

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    Coastal wave refraction imaged by the Seasat Synthetic Aperture Radar is compared to simulations produced by the Virginian Sea Wave Climate Model. Seasat SAR passes 974 at Cape Hatteras, and 974 and 1404 at Long Island, were examined using OFT and ZTS methods. Results generally confirm the validity of linear wave theory in modeling of shallow-water wave refraction --roughly half the deviations between VSWCM and SAR data for direction and wavelength are within 2 degrees and 10 meters. Convergence of wave orthogonals is found in predicted caustic regions. Available bathymetric data were adequate for the analysis. Some details in the pattern of deviations near Cape Hatteras suggested current shear and tidal effects associated with the Gulf Stream

    Elizabeth River Surface Circulation Atlas

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    The Elizabeth River Surface Circulation Atlas is a compendium of maps which detail the surface circulation throughout the main branch of the Elizabeth River, in the port of Hampton Roads, Virginia. Data for the Atlas maps were obtained directly from field experiments using Remote Sensing and dye-emitting low-windage surface drogues. The maps show surface Lagrangian trajectories under various combinations of wind and tide. The Atlas is not intended to duplicate NOAA tidal current tables, but rather to supplement the tables with empirical trajectory data at increased spatial resolution. Knowledge of surface currents under different tide and wind conditions enables a user to predict the movement of floating debris, such as oil spills, within the Elizabeth River Basin

    Prioriy Problems and Data Needs in Coastal Zone Oceanography Earth Observation Satellite Planning

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    Coastal zone oceanographic problems and data needs have been defined for an oceanographic satellite. Problems are based on national and coastal zone priorities. Descriptions of the problems discuss the data needs and the expected utility of remote measurement. Data needs and resolution requirements are specified for surface and satellite measurement. Remote measurables are numerically ranked and evaluated. Coordination of the ERTS program with DOE is discussed

    Plant geography and water quality data for Chesapeake Bay waters of Virginia\u27s Eastern Shore

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    Plant geography and water quality data were collected in shallow water near Cape Charles and Occohannock Creek, Virginia on two occasions. Data from April, 1978 included hydrography, distribution and abundance of -submerged aquatic vegetation, phytoplankton census, and water clarity data. Data from May, 1978 included hydrography, phytoplankton census, water clarity, and primary productivity data. The May data collection was coincident with an overflight of the NASA JSC C-130 aircraft (6600 m) acquiring color infrared photography and multispectral scanner data; cell concentrations reached 105/ml, chlorophyll~ 72 pg/1, and suspended sediment 94 mg/1.

    Interactome Analysis Of The Human Respiratory Syncytial Virus Rna Polymerase Complex Identifies Protein Chaperones As Important Cofactors That Promote L-protein Stability And Rna Synthesis

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    The human respiratory syncytial virus (HRSV) core viral RNA polymerase comprises the large polymerase protein (L) and its cofactor, the phosphoprotein (P), which associate with the viral ribonucleoprotein complex to replicate the genome and, together with the M2-1 protein, transcribe viral mRNAs. While cellular proteins have long been proposed to be involved in the synthesis of HRSV RNA by associating with the polymerase complex, their characterization has been hindered by the difficulty of purifying the viral polymerase from mammalian cell culture. In this study, enhanced green fluorescent protein (EGFP)-tagged L-and P-protein expression was coupled with high-affinity anti-GFP antibody-based immunoprecipitation and quantitative proteomics to identify cellular proteins that interacted with either the L-or the P-proteins when expressed as part of a biologically active viral RNP. Several core groups of cellular proteins were identified that interacted with each viral protein including, in both cases, protein chaperones. Ablation of chaperone activity by using small-molecule inhibitors confirmed previously reported studies which suggested that this class of proteins acted as positive viral factors. Inhibition of HSP90 chaperone function in the current study showed that HSP90 is critical for L-protein function and stability, whether in the presence or absence of the P-protein. Inhibition studies suggested that HSP70 also disrupts virus biology and might help the polymerase remodel the nucleocapsid to allow RNA synthesis to occur efficiently. This indicated a proviral role for protein chaperones in HRSV replication and demonstrates that the function of cellular proteins can be targeted as potential therapeutics to disrupt virus replication. IMPORTANCE Human respiratory syncytial virus (HRSV) represents a major health care and economic burden, being the main cause of severe respiratory infections in infants worldwide. No vaccine or effective therapy is available. This study focused on identifying those cellular proteins that potentially interact specifically with the viral proteins that are central to virus replication and transcription, with a view to providing potential targets for the development of a specific, transient therapeutic which disrupts virus biology but prevents the emergence of resistance, while maintaining cell viability. In particular, protein chaperones (heat shock proteins 70 and 90), which aid protein folding and function, were identified. The mechanism by which these chaperones contribute to virus biology was tested, and this study demonstrates to the field that cellular protein chaperones may be required for maintaining the correct folding and therefore functionality of specific proteins within the virus replication complex.892917930Medical Research Council (MRC) [MR/K000276/1]MRC studentshipNIHRNIH [R01AI074903

    Investigating the Influence of Ribavirin on Human Respiratory Syncytial Virus RNA Synthesis by Using a High-Resolution Transcriptome Sequencing Approach

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    Human respiratory syncytial virus (HRSV) is a major cause of serious respiratory tract infection. Treatment options include administration of ribavirin, a purine analog, although the mechanism of its anti-HRSV activity is unknown. We used transcriptome sequencing (RNA-seq) to investigate the genome mutation frequency and viral mRNA accumulation in HRSV-infected cells that were left untreated or treated with ribavirin. In the absence of ribavirin, HRSV-specific transcripts accounted for up to one-third of total RNA reads from the infected-cell RNA population. Ribavirin treatment resulted in a>90% reduction in abundance of viral mRNA reads, while at the same time no such reduction was detected for the abundance of cellular transcripts. The presented data reveal that ribavirin significantly increases the frequency of HRSV-specific RNA mutations, suggesting a direct influence on the fidelity of the HRSV polymerase. The presented data show that transitions and transversions occur during HRSV replication and that these changes occur in hot spots along the HRSV genome. Examination of nucleotide substitution rates in the viral genome indicated an increase in the frequency of transition but not transversion mutations in the presence of ribavirin. In addition, our data indicate that in the continuous cell types used and at the time points analyzed, the abundances of some HRSV mRNAs do not reflect the order in which the mRNAs are transcribed
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