Processing techniques development, volume 3

The author has identified the following significant results. Analysis of the geometric characteristics of the aircraft synthetic aperture radar (SAR) relative to LANDSAT indicated that relatively low order polynominals would model the distortions to subpixel accuracy to bring SAR into registration for good quality imagery. Also the area analyzed was small, about 10 miles square, so this is an additional constraint. For the Air Force/ERIM data, none of the tested methods could achieve subpixel accuracy. Reasons for this is unknown; however, the noisy (high scintillation) nature of the data and attendent unrecognizability of features contribute to this error. It is concluded that the quadratic model would adequately provide distortion modeling for small areas, i.e., 10 to 20 miles square

The ICT Health Checkup Tool: Assessing Connectivity of the National Agriculture Research System (NARS)

In the global knowledge economy, connectivity is the oxygen for any research and development institutions such as those within the National Agriculture Research System (NARS). The need to empower the NARS to assume research and development leadership requires superior information communication technology (ICT) infrastructure. Specifically, the manuscript addresses two new research questions: 1) what is the state, both quantitatively and qualitatively, of ICT at a NARS institution, and 2) what should a tool look like whereby NARS network managers can on their own benchmark and monitor the state of their ICT systems. The research team employs the case study method to measure the state of ICT connectivity for the Savanna Agricultural Research Institute (SARI), a leading station within the Council for Scientific and Industrial Research of Ghana. Additionally, the research team develops, describes, and applies a new assessment tool, the ICT Health Checkup, which NARS and higher education institutions can utilize. This research fills a void in the ICT for development literature, which to date provides no guidance for research institutions in the developing world as to how they are to access the connectivity they need to be able to provide scientific leadership at the national, regional, and international level. The  results quantify the gap between the needs of the researchers, support staff, and administration and the available service. Additionally, the ICT Health Checkup Tool not only shows NARS leadership their connectivity gaps, but also provides specific and measurable  benchmarks of the physical infrastructure, intranet services, and capacity of the ICT staff. Finally, the case study provides important insights as to the way forward. The case motivates the underlying economies of scale associated with ICT systems, and the need for NARS to leave the current model of individual contracts with telecom providers. Collaborating with like institutions aggregates demand, which in turn lowers the costs per unit of bandwidth. In this vein, the case study shows the value of the relatively new National Research and Education (NREN) model to bring much needed connectivity to the region’s agricultural researchers. Key words: Information and Communication Technology, connectivity, Ghana, National Research and Education Networ

Use and uncertainties of mutual information for computed tomography/magnetic resonance (CT/MR) registration post permanent implant of the prostate

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134844/1/mp1920.pd

High-pressure melt curve of shock-compressed tin measured using pyrometry and reflectance techniques

We have developed a new technique to measure the melt curve of a shocked metal sample and have used it to measure the high-pressure solid-liquid phase boundary of tin from 10 to 30 GPa and 1000 to 1800 K. Tin was shock compressed by plate impact using a single-stage powder gun, and we made accurate, time-resolved radiance, reflectance, and velocimetry measurements at the interface of the tin sample and a lithium fluoride window. From these measurements, we determined temperature and pressure at the interface vs time. We then converted these data to temperature vs pressure curves and plotted them on the tin phase diagram. The tin sample was initially shocked into the high-pressure solid γ phase, and a subsequent release wave originating from the back of the impactor lowered the pressure at the interface along a constant entropy path (release isentrope). When the release isentrope reaches the solid-liquid phase boundary, melt begins and the isentrope follows the phase boundary to low pressure. The onset of melt is identified by a significant change in the slope of the temperature-pressure release isentrope. Following the onset of melt, we obtain a continuous and highly accurate melt curve measurement. The technique allows a measurement along the melt curve with a single radiance and reflectance experiment. The measured temperature data are compared to the published equation of state calculations. Our data agree well with some but not all of the published melt curve calculations, demonstrating that this technique has sufficient accuracy to assess the validity of a given equation of state model

Suitability of Magnesium Oxide as a Visar Window

Impedance matching of a velocity interferometer for any reflector (VISAR) window to a material under study helps simplify a shock experiment by effectively allowing one to measure an in situ particle velocity. The shock impedance of magnesium oxide (MgO) falls roughly midway between those of sapphire and LiF, two of the most frequently used VISAR window materials. A series of symmetric impact experiments was performed to characterize the suitability of single crystal, (100) oriented magnesium oxide as a VISAR window material. These experiments yielded good results and show the viability of MgO as a VISAR window up to 23 GPa. Results were used to determine window correction factors and, subsequently, to estimate the pressure induced change in index of refraction. In many of the shots in this work we exceeded the Hugoniot elastic limit (HEL) of MgO, and both elastic and plastic waves are evident in the velocity profiles. The presence of both waves within the VISAR window complicates the typical VISAR window correction analysis. Preliminary analysis of the elastic and plastic contributions to the window correction is presented

An amphitropic cAMP-binding protein in yeast mitochondria

ABSTRACT: We describe the first example of a mitochondrial protein with a covalently attached phos-phatidylinositol moiety acting as a membrane anchor. The protein can be metabolically labeled with both stearic acid and inositol. The stearic acid label is removed by phospholipase D whereupon the protein with the retained inositol label is released from the membrane. This protein is a cAMP receptor of the yeast Saccharomyces cereuisiae and tightly associated with the inner mitochondrial membrane. However, it is converted into a soluble form during incubation of isolated mitochondria with Ca2+ and phospholipid (or lipid derivatives). This transition requires the action of a proteinaceous, N-ethylmaleimide-sensitive component of the intermembrane space and is accompanied by a decrease in the lipophilicity of the cAMP receptor. We propose that the component of the intermembrane space triggers the amphitropic behavior of the mitochondrial lipid-modified CAMP-binding protein through a phospholipase activity. Only in recent years specific fatty acids have been recog-nized to play important roles in the association of proteins with membranes. Both noncovalent and covalent interactions be-tween fatty acids and proteins have been reported. Among the latter are GTP-binding proteins (Molenaar et al., 1988)

Melting of tantalum at high pressure determined by angle dispersive x-ray diffraction in a double-sided laser-heated diamond-anvil cell

The high pressure and high temperature phase diagram of Ta has been studied in a laser-heated diamond-anvil cell (DAC) using x-ray diffraction measurements up to 52 GPa and 3800 K. The melting was observed at nine different pressures, being the melting temperature in good agreement with previous laser-heated DAC experiments, but in contradiction with several theoretical calculations and previous piston-cylinder apparatus experiments. A small slope for the melting curve of Ta is estimated (dTm/dP = 24 K/GPa at 1 bar) and a possible explanation for this behaviour is given. Finally, a P-V-T equation of states is obtained, being the temperature dependence of the thermal expansion coefficient and the bulk modulus estimated.Comment: 31 pages, 8 figures, to appear in J.Phys.:Cond.Matte

Genome-Wide Association Analysis of Incident Coronary Heart Disease (CHD) in African Americans: A Short Report

African Americans have the highest rate of mortality due to coronary heart disease (CHD). Although multiple loci have been identified influencing CHD risk in European-Americans using a genome-wide association (GWAS) approach, no GWAS of incident CHD has been reported for African Americans. We performed a GWAS for incident CHD events collected during 19 years of follow-up in 2,905 African Americans from the Atherosclerosis Risk in Communities (ARIC) study. We identified a genome-wide significant SNP (rs1859023, MAF = 31%) located at 7q21 near the PFTK1 gene (HR = 0.57, 95% CI 0.46 to 0.69, p = 1.86×10−08), which replicated in an independent sample of over 8,000 African American women from the Women's Health Initiative (WHI) (HR = 0.81, 95% CI 0.70 to 0.93, p = 0.005). PFTK1 encodes a serine/threonine-protein kinase, PFTAIRE-1, that acts as a cyclin-dependent kinase regulating cell cycle progression and cell proliferation. This is the first finding of incident CHD locus identified by GWAS in African Americans