Resolving the Ripples (and a Mine): High-Resolution Multibeam Survey of Martha\u27s Vineyard ONR Mine Burial Program Field Area

In an effort to better understand the coastal processes responsible for the burial and exposure of small objects on the seafloor, the Office of Naval Research is sponsoring the Mine Burial Program. Among the field areas chosen for this program is the site of the Martha\u27s Vineyard Coastal Observatory (MVCO), a permanent instrumented node in 12 m of water about 500 m off the southern shore of Martha?s Vineyard. In support of the ONR program, several site surveys of the MVCO area have been conducted (see Goff et al); here we report the result of the most recent of these surveys, a very high-resolution multibeam survey aimed at establishing a detailed base map for the region and providing a baseline from which subsequent surveys can measure seafloor change In late July we conducted a five day survey of an approximately 3 x 5 km area surrounding the MVCO node using a Reson 8125 focused multibeam sonar aboard the SAIC survey vessel Ocean Explorer. The 8125 is a newly developed multibeam sonar that operates at 455 kHz and uses dynamic focusing to compensate for the curvature of the wavefront in the near-field. By using a relatively long array, the system can achieve very high spatial resolution (0.5 degree beam width) and with the dynamic focusing, can operate in the near field. The real constraint on resolution using this system is the ability to position the soundings and thus three kinematic DGPS base stations were established on Martha?s Vineyard and three kinematic receivers were used on the survey vessel. The kinematic GPS positioning is also critical to the ability to do repeat surveys with an accuracy high enough to resolve small (less than 10 cm) seafloor changes. Also to aid in our ability to accurately position repeat surveys, divers jetted sonar reflectors into the seafloor to act as fiducials. A super high-resolution (4 m overlap) survey was conducted in a small area surrounding the MVCO node and mine burial sites, a slightly lower resolution survey (12 to 25 m overlap) in a box approximately 1 x 1 km surrounding the ?target box? and a lower resolution survey (25 to 40 m line overlap) in a 3 x 5 km region surrounding the 1 x 1 km box. The Reson 8125 produced approximately 1 gigabyte of data per hour. The bathymetric resolution we were able to achieve was beyond our expectations. The node site and all diver-emplaced reflectors were clearly identified Most amazingly, we are able to resolve fields of individual ripples that are less than 2 cm height. Of particular relevance to the mine burial program was our ability to resolve an instrumented mine that had been deployed earlier by NRL. This mine is buried in a scour depression and is only a few centimeters proud above the base of the depression

A Proposal for Adaptive Software Development Using Elastic Features

When software development projects fall behind schedule decisions must be made as to the tactics to bring the project back on schedule. This paper proposes a technique to categorize and group features for a project so that, rather than adjust resources or short cut phases of the development process, features are adjusted to keep the project on schedule. The project has flexibility based on the amount of work (the features) rather than the number of resources or the schedule. The feature categories are spread across iterations within the project, leading to a fine grained adjustment of the project’s progress in relation to schedul

An Instrument to Assess Client-Server Architecture in an Organizational Setting

This study reports the final results of a delphi panel procedure used to develop an instrument to assess the client-server system architecture in an organization. At present there is no formal instrument that allows an information systems manager to assess an existing CSS architecture. A delphi panel was used to develop a formal instrument for CSS assessment

Complex Network Analysis

The clustering coefficient has two definitions that dominate its use, one by Watts and Strogatz, and the second by Newman. It is critical to identify and report the analytic similarities and differences between the two methods in order to give future researchers guidance on the appropriate method to use in their research. This paper reports on an analytical comparison between the two clustering coefficient definitions. We performed the comparison using analytical derivations to show the mathematical relations between the two definitions, the limits on the analysis, and the impact clustering coefficient values derived from the two definitions

Role of Wilms\u27 Tumor 1 in Sex Development

https://openworks.mdanderson.org/sumexp22/1029/thumbnail.jp

Illinois Precipitation Enhancement Program, Phase 1: Interim Report for 1 September 1971 - 30 June 1972

published or submitted for publicationis peer reviewedOpe

Hydrometeorological analysis of severe rainstorms in Illinois, 1956-1957, with summary of previous storms

Bibliography: p. 79.Enumeration continues through succeeding title

Precision Projector Laboratory: detector characterization with an astronomical emulation testbed

As astronomical observations from space benefit from improved sensitivity, the effectiveness of scientific programs is becoming limited by systematics that often originate in poorly understood image sensor behavior. Traditional, bottom-up detector characterization methods provide one way to model underlying detector physics and generate ever more faithful numerical simulations, but this approach is vulnerable to preconceptions and over-simplification. The alternative top-down approach is laboratory emulation, which enables observation, calibration, and analysis scenarios to be tested without relying on a complete understanding of the underlying physics. This complements detector characterization and simulation efforts by testing their validity. We describe a laboratory facility and experimental testbed that supports the emulation of a wide range of mission concepts such as gravitational weak lensing measurements by the Wide Field Infrared Survey Telescope and high precision spectrophotometry of transiting exoplanets by James Webb Space Telescope. An Offner relay projects readily customizable “scenes” (e.g., stars, galaxies, and spectra) with very low optical aberration over the full area of a typical optical or near-infrared image sensor. f  /  8 and slower focal ratios may be selected, spanning those of most proposed space missions and approximating the point spread function (PSF) size of seeing limited ground-based surveys. Diffraction limited PSFs are projected over a wide field of view and wavelength range to deliver highly predictable image patterns down to subpixel scales with stable intensity and fine motion control. The testbed enables realistic validation of detector performance on science-like images, which aids mission design and survey strategy as well as targeted investigations of various detector effects

PEG Branched Polymer for Functionalization of Nanomaterials with Ultralong Blood Circulation

Nanomaterials have been actively pursued for biological and medical applications in recent years. Here, we report the synthesis of several new poly(ethylene glycol) grafted branched-polymers for functionalization of various nanomaterials including carbon nanotubes, gold nanoparticles (NP) and gold nanorods (NRs), affording high aqueous solubility and stability for these materials. We synthesize different surfactant polymers based upon poly-(g-glutamic acid) (gPGA) and poly(maleic anhydride-alt-1-octadecene) (PMHC18). We use the abundant free carboxylic acid groups of gPGA for attaching lipophilic species such as pyrene or phospholipid, which bind to nanomaterials via robust physisorption. Additionally, the remaining carboxylic acids on gPGA or the amine-reactive anhydrides of PMHC18 are then PEGylated, providing extended hydrophilic groups, affording polymeric amphiphiles. We show that single-walled carbon nanotubes (SWNTs), Au NPs and NRs functionalized by the polymers exhibit high stability in aqueous solutions at different pHs, at elevated temperatures and in serum. Morever, the polymer-coated SWNTs exhibit remarkably long blood circulation (t1/2 22.1 h) upon intravenous injection into mice, far exceeding the previous record of 5.4 h. The ultra-long blood circulation time suggests greatly delayed clearance of nanomaterials by the reticuloendothelial system (RES) of mice, a highly desired property for in vivo applications of nanomaterials, including imaging and drug delivery

A rapid and sensitive assay for quantification of siRNA efficiency and specificity

RNA Interference has rapidly emerged as an efficient procedure for knocking down gene expression in model systems. However, cross-reactivity, whereby multiple genes may be simultaneously targeted by a single short interfering RNA (siRNA), can potentially jeopardize correct interpretation of gene function. As such, it is essential to test the specificity of a siRNA prior to a full phenotypic analysis. To this end, we have adapted a reporter-based assay harnessing the sensitivity of luciferase activity to provide a quantitative readout of relative RNAi efficacy and specificity. We have tested different siRNAs directed against Thymosin β4 (Tβ4); determined their effectiveness at silencing Tβ4 and have both excluded off-target silencing of the Tβ4 homologue Thymosin β10 (Tβ10) and demonstrated partial knockdown of Tβ10 despite significant (12/23; 52%) sequence mismatch. This assay system is applicable to any RNAi study where there is a risk of targeting homologous genes and to the monitoring of off-target effects at the genome level following microarray expression profiling