Article on environmental and genetic preconditioning for long-term anoxia responses requires AMPK in Caenorhabditis elegans.

Hybrid magnet theory as applied to the error analyses usedin the design of Advanced Light Source (ALS) insertion devices isreviewed. Sources of field errors in hybrid insertion devices arediscussed.

Under the Nuclear/Radiological Incident Annex of the National Response Framework, the U.S. Department of Energy (DOE) has specific responsibilities as a coordinating agency and for leading interagency response elements in the Federal Radiological Monitoring and Assessment Center (FRMAC). Emergency response planning focuses on rapidly providing response elements in stages after being notified of a nuclear/radiological incident. The use of Home Teams during the field team deployment period and recent advances in collecting and transmitting data from the field directly to assessment assets has greatly improved incident assessment times for public protection decisions. The DOE’s Remote Sensing Laboratory (RSL) based in Las Vegas, Nevada, has successfully deployed technical and logistical support for this mission at national exercises such as Top Officials Exercise IV (TOPOFF IV). In a unique response situation, DOE will provide advance contingency support to NASA during the scheduled launch in the fall of 2009 of the Mars Science Laboratory (MSL). The MSL rover will carry a radioisotope power system that generates electricity from the heat of plutonium’s radioactive decay. DOE assets and contingency planning will provide a pre-incident response posture for rapid early plume phase assessment in the highly unlikely launch anomaly.

Plant mounds or blow-sand mounds are accumulations of soil particles and plant debris around the base of shrubs and are common features in deserts in the southwestern United States. An important factor in their formation is that shrubs create surface roughness that causes wind-suspended particles to be deposited and resist further suspension. Shrub mounds occur in some plant communities on the Nevada Test Site, the Nevada Test and Training Range (NTTR), and Tonopah Test Range (TTR), including areas of surface soil contamination from past nuclear testing. In the 1970s as part of early studies to understand properties of actinides in the environment, the Nevada Applied Ecology Group (NAEG) examined the accumulation of isotopes of Pu, 241Am, and U in plant mounds at safety experiment and storage-transportation test sites of nuclear devices. Although aerial concentrations of these contaminants were highest in the intershrub or desert pavement areas, the concentration in mounds were higher than in equal volumes of intershrub or desert pavement soil. The NAEG studies found the ratio of contaminant concentration of actinides in soil to be greater (1.6 to 2.0) in shrub mounds than in the surrounding areas of desert pavement. At Project 57 on the NTTR, 17 percent …

This document summarizes the findings of the Accelerator Working Group (AWG) of the International Scoping Study (ISS) of a Future Neutrino Factory and Superbeam Facility. The work of the group took place at three plenary meetings along with three workshops, and an oral summary report was presented at the NuFact06 workshop held at UC-Irvine in August, 2006. The goal was to reach consensus on a baseline design for a Neutrino Factory complex. One aspect of this endeavor was to examine critically the advantages and disadvantages of the various Neutrino Factory schemes that have been proposed in recent years.

Dramatic advances in data management have been made as a result of the Paperless FRMAC initiative, sponsored by the DOE’s Office of Emergency Response (NA-42). The FRMAC (Federal Radiological Monitoring and Assessment Center) is the hub for all radiological monitoring and the production of data products that interpret those measurements in terms of protective action guidelines. As such, very large amounts of data must be quickly assimilated from numerous sources and then widely distributed as graphical interpretations as fast as possible. Paperless FRMAC is a broad initiative to move that data faster, farther and better through telemetry, automation, and networking. This discussion reviews for the first time the status of the now two-year-old Paperless FRMAC initiative. Key features of Paperless FRMAC include multipath telemetry of measurements from DOE field teams, 24/7 Internet presence, early data entry by first responders, support for distance collaborations, and data exchange with the EPA’s SCRIBE database. The heart of the enterprise is the RAMS database, which provides seamless interfacing with GIS, LIMS, and TurboFRMAC for calculations. Paperless FRMAC is presented to users via two Internet websites. The first, FRMAC Portal website, is restricted to the emergency responders for data input, analysis, and product development. The …

Thermodynamic properties of strongly coupled (high density) plasmas of mixtures of light elements have been obtained by Monte Carlo simulations. For an assumed uniform charge background the equation of state of ionic mixtures is a simple extension of the one-component plasma EOS. More realistic electron screening effects are treated in linear response theory and with an appropriate electron dielectric function. Results have been obtained for the ionic pair distribution functions, and for the electric microfield distribution.

Hybrid codes in which part of the plasma is represented as particles and the rest as fluid are discussed. In the past few years such codes with particle ions and massless, fluid electrons have been applied to space plasmas, especially to collisionless shocks. All of these simulation codes are one-dimensional and similar in structure, except for how the field equation are solved. We describe in detail the various approaches that are used (resistive Ohm's law, predictor-corrector, Hamiltonian) and compare results from the various codes with examples taken from collisionless shocks and low frequency wave phenomena upstream of shocks.

The presence of high concentrations of uranium in the subsurface can be attributed either to contamination from uranium processing activities or to naturally occurring uranium. A mathematical method has been employed to evaluate the isotope ratios from subsurface soils at the Rocky Flats Nuclear Weapons Plant (RFP) and demonstrates conclusively that the soil contains uranium from a natural source and has not been contaminated with enriched uranium resulting from RFP releases. This paper describes the method used in this determination which has widespread application in site characterizations and can be adapted to other radioisotopes used in manufacturing industries. The determination of radioisotope source can lead to a reduction of the remediation effort.

Better to understand the status of fusion research in the year 2003 we will first put the research in its historical context. Fusion power research, now beginning its sixth decade of continuous effort, is unique in the field of scientific research. Unique in its mixture of pure and applied research, unique in its long-term goal and its promise for the future, and unique in the degree that it has been guided and constrained by national and international governmental policy. Though fusion research's goal has from the start been precisely defined, namely, to obtain a net release of energy from controlled nuclear fusion reactions between light isotopes (in particular those of hydrogen and helium) the difficulty of the problem has spawned in the past a very wide variety of approaches to the problem. Some of these approaches have had massive international support for decades, some have been pursued only at a ''shoestring'' level by dedicated groups in small research laboratories or universities. In discussing the historical and present status of fusion research the implications of there being two distinctly different approaches to achieving net fusion power should be pointed out. The first, and oldest, approach is the use of strong magnetic …

In this paper we propose a novel visibility-culling technique for optimizing the computation and rendering of opaque isosurfaces. Given a continuous scalar field f (x) over a domain D and an isovalue w, our technique exploits the continuity of f to determine conservative visibility bounds implicitly, i.e., without the need for actually computing the isosurface f{sup -1}(w). We generate Implicit Occluders based on the change in sign of f *(x) = f (x)-w, from positive to negative (or vice versa) in the neighborhood of the isosurface. Consider, for example, the sign of f * along a ray r cast from the current viewpoint. The first change in sign of f * within D must contain an intersection of r with the isosurface. Any additional intersection of the isosurface with r is not visible. Implicit Occluders constitute a general concept that can be exploited algorithmically in different ways depending on the framework adopted for visibility computations. In this paper, we propose a simple from-point approach that exploits well-known hardware occlusion queries.

The mobilization of arsenic was examined in a system where the deposition of iron and arsenic have been substantially modified by large-scale manipulations. This engineering practice was designed to decrease arsenic concentrations in water supplied to the City of Los Angeles. Accomplishing this objective, however, has resulted in significant accumulation of arsenic and iron in the sediments of a reservoir on the Los Angeles Aqueduct. Arsenic and iron are released into the porewater at depth in the sediment, consistent with reductive dissolution of iron(III) oxyhydroxides. Factors influencing the possible re-sorption of arsenic onto residual iron(III) oxyhydroxides solids have been examined. Reduction of As(V) to As(III) alone cannot account for arsenic mobilization since arsenic occurs in the solid phase as As(III) well above the depth at which it is released into the porewater. Competition from other porewater constituents could suppress re-sorption of arsenic released by reductive dissolution.

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The compressibility of fluid deuterium up to several Mbar has been probed using laser-driven shock waves reflected from a quartz anvil. Combining high-precision ({approx} 1 %) shock velocity measurements with the double-shock technique, where differences in equation of state (EOS) models are magnified, has allowed us to accurately discriminate between various theoretical predictions. Our data are consistent with EOS models that show approximately fourfold compression on the principal Hugoniot from 0.7 to 1 Mbar; however, our results indicate that deuterium has a higher compressibility than predicted by these models for single shock pressures between 1 and 2.5 Mbar.

We present a simple method for compressing very large and regularly sampled scalar fields. Our method is particularly attractive when the entire data set does not fit in memory and when the sampling rate is high relative to the feature size of the scalar field in all dimensions. Although we report results for R{sup 3} and R{sup 4} data sets, the proposed approach may be applied to higher dimensions. The method is based on the new Lorenzo predictor, introduced here, which estimates the value of the scalar field at each sample from the values at processed neighbors. The predicted values are exact when the n-dimensional scalar field is an implicit polynomial of degree n-1. Surprisingly, when the residuals (differences between the actual and predicted values) are encoded using arithmetic coding, the proposed method often outperforms wavelet compression in an L{infinity} sense. The proposed approach may be used both for lossy and lossless compression and is well suited for out-of-core compression and decompression, because a trivial implementation, which sweeps through the data set reading it once, requires maintaining only a small buffer in core memory, whose size barely exceeds a single n-1 dimensional slice of the data.

The Gordon Research Conference on 'Molecular and Ionic Clusters' focuses on clusters, which are the initial molecular species found in gases when condensation begins to occur. Condensation can take place solely from molecules interacting with each other, mostly at low temperatures, or when molecules condense around charged particles (electrons, protons, metal cations, molecular ions), producing ion molecule clusters. These clusters provide models for solvation, allow a pristine look at geometric as well as electronic structures of molecular complexes or matter in general, their interaction with radiation, their reactivity, their thermodynamic properties and, in particular, the related dynamics. This conference focuses on new ways to make clusters composed of different kinds of molecules, new experimental techniques to investigate the properties of the clusters and new theoretical methods with which to calculate the structures, dynamical motions and energetics of the clusters. Some of the main experimental methods employed include molecular beams, mass spectrometry, laser spectroscopy (from infrared to XUV; in the frequency as well as the time domain) and photoelectron spectroscopy. Techniques include laser absorption spectroscopy, laser induced fluorescence, resonance enhanced photoionization, mass-selected photodissociation, photofragment imaging, ZEKE photoelectron spectroscopy, etc. From the theoretical side, this conference highlights work on potential surfaces and …

We have discovered what appear to be micrometeorites imbedded in seven late Pleistocene Alaskan mammoth tusks and a Siberian bison skull. The micrometeorites apparently shattered on impact leaving 2 to 5 mm hemispherical debris patterns surrounded by carbonized rings. Multiple impacts are observed on only one side of the tusks and skull consistent with the micrometeorites having come from a single direction. The impact sites are strongly magnetic indicating significant iron content. We analyzed several imbedded micrometeorite fragments from both tusks and skull with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and X-ray fluorescence (XRF). These analyses confirm the high iron content and indicate compositions highly enriched in nickel and depleted in titanium, unlike any natural terrestrial sources. In addition, electron microprobe (EMP) analyses of a Fe-Ni sulfide grain (tusk 2) show it contains between 3 and 20 weight percent Ni. Prompt gamma-ray activation analysis (PGAA) of a particle extracted from the bison skull indicates ~;;0.4 mg of iron, in agreement with a micrometeorite ~;;1 mm in diameter. In addition, scanning electron microscope (SEM) images and XRF analyses of the skull show possible entry channels containing Fe-rich material. The majority of tusks (5/7) have a calibrated weighted mean 14C …

Lensless X-ray imaging techniques such as coherent diffraction imaging and ptychography, and Fourier transform holography can provide time-resolved, diffraction-limited images. Nearly all examples of these techniques have focused on transmission geometry, restricting the samples and reciprocal spaces that can be investigated. We report a lensless X-ray technique developed for imaging in Bragg and small-angle scattering geometries, which may also find application in transmission geometries. We demonstrate this by imaging a nanofabricated pseudorandom binary structure in small-angle reflection geometry. The technique can be used with extended objects, places no restriction on sample size, and requires no additional sample masking. The realization of X-ray lensless imaging in reflection geometry opens up the possibility of single-shot imaging of surfaces in thin films, buried interfaces in magnetic multilayers, organic photovoltaic and field-effect transistor devices, or Bragg planes in a single crystal.

In mechanical tests of tantalum-tungsten alloys with nominal tungsten contents between 0 and 10 wt % for strain rates between 0.000016 and 6800s{sup {minus}1} and temperatures between 77 and 400 K, the addition of tungsten noticeably reduces the strain-rate dependence of the flow stress of tantalum near yield. It also subtly alters the strain-rate behavior of the work hardening, making it more like that of copper, an fcc metal. These effects are reflected in the limiting strains for uniform plastic deformation calculated from our flow curves. For unalloyed tantalum, the instability strain appears to drop dramatically for strain rates in excess of approximately 0.005s{sup {minus}1}, whereas for tungsten bearing alloys, it remains unchanged or increases slightly. Tungsten alloys may therefore be preferable to unalloyed tantalum in applications that demand substantial ductility at high rates of strain. We briefly discuss possible mechanisms for plastic flow in tantalum and how they might be affected by tungsten additions to produce the effects we observe.

Differentiating erythroid cells execute a unique gene expression program that insures synthesis of the appropriate proteome at each stage of maturation. Standard expression microarrays provide important insight into erythroid gene expression but cannot detect qualitative changes in transcript structure, mediated by RNA processing, that alter structure and function of encoded proteins. We analyzed stage-specific changes in the late erythroid transcriptome via use of high-resolution microarrays that detect altered expression of individual exons. Ten differentiation-associated changes in erythroblast splicing patterns were identified, including the previously known activation of protein 4.1R exon 16 splicing. Six new alternative splicing switches involving enhanced inclusion of internal cassette exons were discovered, as well as 3 changes in use of alternative first exons. All of these erythroid stage-specific splicing events represent activated inclusion of authentic annotated exons, suggesting they represent an active regulatory process rather than a general loss of splicing fidelity. The observation that 3 of the regulated transcripts encode RNA binding proteins (SNRP70, HNRPLL, MBNL2) may indicate significant changes in the RNA processing machinery of late erythroblasts. Together, these results support the existence of a regulated alternative pre-mRNA splicing program that is critical for late erythroid differentiation.

A group of fusion safety professionals contribute to a Joint Working Group (JWG) that performs occupational safety walkthroughs of US and Japanese fusion experiments on a routine basis to enhance the safety of visiting researchers. The most recent walkthrough was completed in Japan in March 2008 by the US Safety Monitor team. This paper gives the general conclusions on fusion facility personnel safety that can be drawn from the series of walkthroughs.

It is anticipated that in the near future disk storage systems will surpass application servers and will become the primary consumer of power in the data centers. Shutting down of inactive disks is one of the more widespread solutions to save power consumption of disk systems. This solution involves spinning down or completely shutting off disks that exhibit long periods of inactivity and placing them in standby mode. A file request from a disk in standby mode will incur an I/O cost penalty as it takes time to spin up the disk before it can serve the file. In this paper, we address the problem of designing and implementing file allocation strategies on disk storage that save energy while meeting performance requirements of file retrievals. We present an algorithm for solving this problem with guaranteed bounds from the optimal solution. Our algorithm runs in O(nlogn) time where n is the number of files allocated. Detailed simulation results and experiments with real life workloads are also presented.

The Linac Coherent Light Source (LCLS) is an x-ray Free-Electron Laser (FEL) project presently in a commissioning phase at SLAC. We report here on very low emittance measurements made at low bunch charge, and a few femtosecond bunch length produced by the LCLS bunch compressors. Start-to-end simulations associated with these beam parameters show the possibilities of generating hundreds of GW at 1.5 {angstrom} x-ray wavelength and nearly a single longitudinally spike at 1.5 nm with 2-fs duration.

A new rapid method for the determination of actinides and strontium in air filter samples has been developed at the Savannah River Site Environmental Lab (Aiken, SC, USA) that can be used in emergency response situations. The actinides and strontium in air filter method utilizes a rapid acid digestion method and a streamlined column separation process with stacked TEVA, TRU and Sr Resin cartridges. Vacuum box technology and rapid flow rates are used to reduce analytical time. Alpha emitters are prepared using cerium fluoride microprecipitation for counting by alpha spectrometry. The purified {sup 90}Sr fractions are mounted directly on planchets and counted by gas flow proportional counting. The method showed high chemical recoveries and effective removal of interferences. This new procedure was applied to emergency air filter samples received in the NRIP Emergency Response exercise administered by the National Institute for Standards and Technology (NIST) in April, 2009. The actinide and {sup 90}Sr in air filter results were reported in {approx}4 hours with excellent quality.