Several proteins involved in the response to DNA doublestrand breaks (DSB) f orm microscopically visible nuclear domains, orfoci, after exposure to ionizing radiation. Radiation-induced foci (RIF)are believed to be located where DNA damage occurs. To test thisassumption, we analyzed the spatial distribution of 53BP1, phosphorylatedATM, and gammaH2AX RIF in cells irradiated with high linear energytransfer (LET) radiation and low LET. Since energy is randomly depositedalong high-LET particle paths, RIF along these paths should also berandomly distributed. The probability to induce DSB can be derived fromDNA fragment data measured experimentally by pulsed-field gelelectrophoresis. We used this probability in Monte Carlo simulations topredict DSB locations in synthetic nuclei geometrically described by acomplete set of human chromosomes, taking into account microscope opticsfrom real experiments. As expected, simulations produced DNA-weightedrandom (Poisson) distributions. In contrast, the distributions of RIFobtained as early as 5 min after exposure to high LET (1 GeV/amu Fe) werenon-random. This deviation from the expected DNA-weighted random patterncan be further characterized by "relative DNA image measurements." Thisnovel imaging approach shows that RIF were located preferentially at theinterface between high and low DNA density regions, and were morefrequent than predicted in regions with lower DNA density. The samepreferential nuclear location was also measured …

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Groundwater is sampled from 39 monitoring wells on the Nevada Test Site (NTS) as part of the Routine Radiological Environmental Monitoring Program. Many of these wells were not designed or constructed for long-term groundwater monitoring. Some have extensive completion zones and others have obstructions such as pumps and tubing. The high-volume submersible pumps in some wells are unsuitable for long-term monitoring and result in large volumes of water that may have to be contained and characterized before subsequent disposition. The configuration of most wells requires sampling stagnant well water with a wireline bailer. Although bailer sampling allows for the collection of depth-discrete samples, the collected samples may not be representative of local groundwater because no well purging is done. Low-maintenance, solar-powered jack pumps will be deployed in nine of these onsite monitoring wells to improve sample quality. These pumps provide the lift capacity to produce groundwater from the deep aquifers encountered in the arid environment of the NTS. The water depths in these wells range from 700 to 2,340 ft below ground surface. The considerable labor and electrical power requirements of electric submersible pumps are eliminated once these pumps are installed. Access tubing will be installed concurrent with the installation …

Different methods for the calculation of cross sections with many QCD particles are compared. To this end, CSW vertex rules, Berends-Giele recursion and Feynman-diagram based techniques are implemented as well as various methods for the treatment of colours and phase space integration. We find that typically there is only a small window of jet multiplicities, where the CSW technique has efficiencies comparable or better than both of the other two methods.

X-ray photoelectron spectroscopy (XPS) is a quantitative, chemically specific technique with a probing depth of a few angstroms to a few nanometers. It is therefore ideally suited to investigate the chemical nature of the surfaces of catalysts. Because of the scattering of electrons by gas molecules, XPS is generally performed under vacuum conditions. However, for thermodynamic and/or kinetic reasons, the catalyst's chemical state observed under vacuum reaction conditions is not necessarily the same as that of a catalyst under realistic operating pressures. Therefore, investigations of catalysts should ideally be performed under reaction conditions, i.e., in the presence of a gas or gas mixtures. Using differentially pumped chambers separated by small apertures, XPS can operate at pressures of up to 1 Torr, and with a recently developed differentially pumped lens system, the pressure limit has been raised to about 10 Torr. Here, we describe the technical aspects of high-pressure XPS and discuss recent applications of this technique to oxidation and heterogeneous catalytic reactions on metal surfaces.

Control Banding (CB) strategies offer simplified solutions for controlling worker exposures to constituents that are found in the workplace in the absence of firm toxicological and exposure data. These strategies may be particularly useful in nanotechnology applications, considering the overwhelming level of uncertainty over what nanomaterials and nanotechnologies present as potential work-related health risks, what about these materials might lead to adverse toxicological activity, how risk related to these might be assessed, and how to manage these issues in the absence of this information. This study introduces a pilot CB tool or 'CB Nanotool' that was developed specifically for characterizing the health aspects of working with engineered nanoparticles and determining the level of risk and associated controls for five ongoing nanotechnology-related operations being conducted at two Department of Energy (DOE) research laboratories. Based on the application of the CB Nanotool, four of the five operations evaluated in this study were found to have implemented controls consistent with what was recommended by the CB Nanotool, with one operation even exceeding the required controls for that activity. The one remaining operation was determined to require an upgrade in controls. By developing this dynamic CB Nanotool within the realm of the scientific information …

Synchrotron radiation (SR) methods have been utilized with increasing frequency over the past several years to study topics in actinide science, ranging from those of a fundamental nature to those that address a specifically-targeted technical need. In particular, the emergence of microspectroscopic and fluorescence-based techniques have permitted investigations of actinide materials at sources of soft x-ray SR. Spectroscopic techniques with fluorescence-based detection are useful for actinide investigations since they are sensitive to small amounts of material and the information sampling depth may be varied. These characteristics also serve to simplify both sample preparation and safety considerations. Examples of investigations using these fluorescence techniques will be described along with their results, as well as the prospects for future investigations utilizing these methodologies.

Industrial processes use mechanical draft cooling towers (MDCT's) to dissipate waste heat by transferring heat from water to air via evaporative cooling, which causes air humidification. The Savannah River Site (SRS) has a MDCT consisting of four independent compartments called cells. Each cell has its own fan to help maximize heat transfer between ambient air and circulated water. The primary objective of the work is to conduct a parametric study for cooling tower performance under different fan speeds and ambient air conditions. The Savannah River National Laboratory (SRNL) developed a computational fluid dynamics (CFD) model to achieve the objective. The model uses three-dimensional steady-state momentum, continuity equations, air-vapor species balance equation, and two-equation turbulence as the basic governing equations. It was assumed that vapor phase is always transported by the continuous air phase with no slip velocity. In this case, water droplet component was considered as discrete phase for the interfacial heat and mass transfer via Lagrangian approach. Thus, the air-vapor mixture model with discrete water droplet phase is used for the analysis. A series of the modeling calculations was performed to investigate the impact of ambient and operating conditions on the thermal performance of the cooling tower when fans …

Two Si-based spintronic materials, a Mn-Si digital ferromagnetic heterostructure ({delta}-layer of Mn doped in Si) with defects and dilutely doped Mn{sub x}Si{sub 1-x} alloy are investigated using a density-functional based approach. We model the heterostructure and alloy with a supercell of 64 atoms and examine several configurations of the Mn atoms. We find that 25% substitutional defects without vacancies in the {delta} layer diminishes half metallicity of the DFH substantially. For the alloy, the magnetic moment M ranges from 1.0-9.0 {mu}{sub B}/unit-cell depending on impurity configuration and concentration. Mn impurities introduce a narrow band of localized states near E{sub F}. These alloys are not half metals though their moments are integer. We explain the substantially different magnetic moments.

Nucleic acid aptamers have found steadily increased utility and application steadily over the last decade. In particular, aptamers have been touted as a valuable complement to and in some cases replacement for antibodies due to their structural and functional robustness as well as their ease in generation and synthesis. They are thus attractive for biosecurity applications, e.g. pathogen detection, and are especially well suited since their in vitro generation process does not require infection of any host systems. Herein we provide a brief overview of the aptamers generated against biopathogens over the last few years. In addition, a few recently described detection platforms using aptamers (aptasensors) and potentially suitable for biosecurity applications will be discussed.

This manuscript discusses the multilayer coating results for the primary and secondary mirrors of the Micro Exposure Tool (MET): a 0.30-numerical aperture (NA) lithographic imaging system with 200 x 600 {micro}m{sup 2} field of view at the wafer plane, operating in the extreme ultraviolet (EUV) wavelength region. Mo/Si multilayers were deposited by DC-magnetron sputtering on large-area, curved MET camera substrates, and a velocity modulation technique was implemented to consistently achieve multilayer thickness profiles with added figure errors below 0.1 nm rms to achieve sub-diffraction-limited performance. This work represents the first experimental demonstration of sub-diffraction-limited multilayer coatings for high-NA EUV imaging systems.

An all-inorganic photocatalytic unit consisting of a binuclear TiOCr charge-transfer chromophore coupled to an Ir oxide nanocluster has been assembled on the pore surface of mesoporous silica AlMCM-41. In situ FT-Raman and EPR spectroscopy of an aqueous suspension of the resulting IrxOy-TiCr-AlMCM-41 powder reveal the formation of superoxide species when exciting the Ti(IV)OCr(III) --> Ti(III)OCr(IV) metal-to-metal charge-transfer chromophore with visible light. Use of H218O confirms that the superoxide species originates from oxidation of water. Photolysis in the absence of persulfate acceptor leads to accumulation of Ti(III) instead. The results are explained by photocatalytic oxidation of water at Ir oxide nanoclusters followed by trapping of the evolving O2 by transient Ti(III) centers to yield superoxide. Given the flexibility to select donor metals with appropriate redox potential, photocatalytic units consisting of a binuclear charge-transfer chromophore coupled to a water oxidation catalyst shown here constitute a step towards thermodynamically efficient visible light water oxidation units.

In areas composed of coastal plain sediments, soft zones subjected to partial overburden may be present in the subsurface. During or after a seismic event, these soft zones may be compressed. The resulting displacement due to the deformation of the soft zones will propagate to the ground surface and cause the surface to settle. This paper presents a method to predict the settlement at the surface due to the propagation of the displacement from the soft zones. This method is performed by discretizing the soft zones into multiple clusters of finite sub-areas or subspaces. Settlement profile at the ground surface due to the displacement of each sub-area or subspace is computed assuming the shape is a normal distribution function. Settlement due to the displacement of the soft zones can then be approximated by adding the settlements computed for all the sub-areas or subspaces. This method provides a simple and useful tool for the prediction of the settlement profile and the results are consistent with those obtained from the finite difference analysis.

The Translational Research Working Group (TRWG) was created as a national initiative to evaluate the current status of NCI's investment in translational research and envision its future. The TRWG conceptualized translational research as a set of six developmental processes or pathways focused on various clinical goals. One of those pathways describes the development of biospecimen-based assays that utilize biomarkers for the detection, diagnosis, prognosis, and assessment of response to cancer treatment. The biospecimen-based assessment modality (BM) pathway was conceived not as comprehensive description of the corresponding real-world processes, but rather as a tool designed to facilitate movement of a candidate assay through the translational process to the point where it can be handed off for definitive clinical testing. This paper introduces the pathway in the context of prior work and discusses key challenges associated with the biomarker development process in light of the pathway.

We have developed a new target platform to study Laser Plasma Interaction in ignition-relevant condition at the Omega laser facility (LLE/Rochester)[1]. By shooting an interaction beam along the axis of a gas-filled hohlraum heated by up to 17 kJ of heater beam energy, we were able to create a millimeter-scale underdense uniform plasma at electron temperatures above 3 keV. Extensive Thomson scattering measurements allowed us to benchmark our hydrodynamic simulations performed with HYDRA [1]. As a result of this effort, we can use with much confidence these simulations as input parameters for our LPI simulation code pF3d [2]. In this paper, we show that by using accurate hydrodynamic profiles and full three-dimensional simulations including a realistic modeling of the laser intensity pattern generated by various smoothing options, fluid LPI theory reproduces the SBS thresholds and absolute reflectivity values and the absence of measurable SRS. This good agreement was made possible by the recent increase in computing power routinely available for such simulations.

DOE-2 building energy simulations were conducted to determine if there were practical architectural and control strategy solutions that would enable electrochromic (EC) windows to significantly improve visual comfort without eroding energy-efficiency benefits. EC windows were combined with overhangs since opaque overhangs provide protection from direct sun which EC windows are unable to do alone. The window wall was divided into an upper and lower aperture so that various combinations of overhang position and control strategies could be considered. The overhang was positioned either at the top of the upper window aperture or between the upper and lower apertures. Overhang depth was varied. EC control strategies were fully bleached at all times, modulated based on incident vertical solar radiation limits, or modulated to meet the design work plane illuminance with daylight. The EC performance was compared to a state-of-the-art spectrally selective low-e window with the same divided window wall, window size, and overhang as the EC configuration. The reference window was also combined with an interior shade which was manually deployed to control glare and direct sun. Both systems had the same daylighting control system to dim the electric lighting. Results were given for south-facing private offices in a typical commercial …

Shadows cast by trees and buildings can limit the solar access of rooftop solar-energy systems, including photovoltaic panels and thermal collectors. This study characterizes rooftop shading in a residential neighborhood of San Jose, CA, one of four regions analyzed in a wider study of the solar access of California homes.High-resolution orthophotos and LiDAR (Light Detection And Ranging) measurements of surface height were used to create a digital elevation model of all trees and buildings in a 4 km2 residential neighborhood. Hourly shading of roofing planes (the flat elements of roofs) was computed geometrically from the digital elevation model. Parcel boundaries were used to determine the extent to which roofing planes were shaded by trees and buildings in neighboring parcels.In the year in which surface heights were measured (2005), shadows from all sources ("total shading") reduced the insolation received by S-, SW-, and W-facing residential roofing planes in the study area by 13 - 16percent. Shadows cast by trees and buildings in neighboring parcels reduced insolation by no more than 2percent. After 30 years of simulated maximal tree growth, annual total shading increased to 19 - 22percent, and annual extraparcel shading increased to 3 - 4percent.

Using the method of maximal cuts, we obtain a form of the three-loop four-point scattering amplitude of N = 8 supergravity in which all ultraviolet cancellations are made manifest. The Feynman loop integrals that appear have a graphical representation with only cubic vertices, and numerator factors that are quadratic in the loop momenta, rather than quartic as in the previous form. This quadratic behavior reflects cancellations beyond those required for finiteness, and matches the quadratic behavior of the three-loop four-point scattering amplitude in N = 4 super-Yang-Mills theory. By direct integration we confirm that no additional cancellations remain in the N = 8 supergravity amplitude, thus demonstrating that the critical dimension in which the first ultraviolet divergence occurs at three loops is D{sub c} = 6. We also give the values of the three-loop divergences in D = 7, 9, 11. In addition, we present the explicitly color-dressed three-loop four-point amplitude of N = 4 super-Yang-Mills theory.

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Clouds of electrons in the vacuum chambers of accelerators of positively charged particle beams present a serious limitation for operation of these machines at high currents. Because of the size of these accelerators, it is difficult to probe the low energy electron clouds over substantial lengths of the beam pipe. We applied a novel technique to directly measure the electron cloud density via the phase shift induced in a TE wave which is independently excited and transmitted over a straight section of the accelerator. The modulation in the wave transmission which appear to increase in depth when the clearing solenoids are switched off, seem to be directly correlated to the electron cloud density in the section. Furthermore, we expect a larger phase shift of a wave transmitted through magnetic dipole field regions if the transmitted wave couples with the gyration motion of the electrons. We have used this technique to measure the average electron cloud density (ECD) specifically for the first time in magnetic field regions of a new 4-dipole chicane in the positron ring of the PEP-II collider at SLAC. In this paper we present and discuss the measurements taken in the Low Energy Ring (LER) between 2006 and …

Cancer cells are endowed with diverse biological capabilities driven by myriad inherited and somatic genetic and epigenetic aberrations that commandeer key cancer-relevant pathways. Efforts to elucidate these aberrations began with Boveri's hypothesis of aberrant mitoses causing cancer and continue today with a suite of powerful high-resolution technologies that enable detailed catalogues of genomic aberrations and epigenomic modifications. Tomorrow will likely bring the complete atlas of reversible and irreversible alteration in individual cancers. The challenge now is to discern causal molecular abnormalities from genomic and epigenomic 'noise', to understand how the ensemble of these aberrations collaborate to drive cancer pathophysiology. Here, we highlight lessons learned from now classical examples of successful translation of genomic discoveries into clinical practice, lessons that may be used to guide and accelerate translation of emerging genomic insights into practical clinical endpoints that can impact on practice of cancer medicine.

The effect of surface structural damage on graphitic anodes, commonly observed in tested Li-ion cells, was investigated. Similar surface structural disorder was artificially induced in Mag-10 synthetic graphite anodes using argon-ion sputtering. Raman microscopy, scanning electron microscopy (SEM) and Brunauer Emmett Teller (BET) measurements confirmed that Ar-ion sputtered Mag-10 electrodes display similar degree of surface degradation as the anodes from tested Li-ion cells. Artificially modified Mag-10 anodes showed double the irreversible charge capacity during the first formation cycle, compared to fresh un-altered anodes. Impedance spectroscopy and Fourier transform infrared (FTIR) spectroscopy on surface modified graphite anodes indicated the formation of a thicker and slightly more resistive SEI layer. Gas chromatography/mass spectroscopy (GC/MS) analysis of solvent extracts from the electrodes detected the presence of new compounds with M{sub w} on the order of 1600 g mol{sup -1} for the surface modified electrode with no evidence of elevated M{sub w} species for the unmodified electrode. The structural disorder induced in the graphite during long-term cycling maybe responsible for the slow and continuous SEI layer reformation, and consequently, the loss of reversible capacity due to the shift of lithium inventory in cycled Li-ion cells.

The Large Synoptic Survey Telescope (LSST) is a three mirror modified Paul-Baker design with an 8.4m primary, a 3.4m secondary, and a 5.0m tertiary followed by a 3-element refractive corrector producing a 3.5 degree field of view. This design produces image diameters of <0.3 arcsecond 80% encircled energy over its full field of view. The image quality of this design is sufficient to ensure that the final images produced by the telescope will be limited by the atmospheric seeing at an excellent astronomical site. In order to maintain this image quality, the deformations and rigid body motions of the three large mirrors must be actively controlled to minimize optical aberrations. By measuring the optical wavefront produced by the telescope at multiple points in the field, mirror deformations and rigid body motions that produce a good optical wavefront across the entire field may be determined. We will describe the details of the techniques for obtaining these solutions. We will show that, for the expected mirror deformations and rigid body misalignments, the solutions that are found using these techniques produce an image quality over the field that is close to optimal. We will discuss how many wavefront sensors are needed and the …

We report on an analysis of {tau}{sup -} decaying into {omega}{pi}{sup -}{nu}{sub {tau}} with {omega} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup 0} using data containing nearly 320 million tau pairs collected with the BABAR detector at the PEP-II asymmetric energy B-Factory. We find no evidence for second-class currents and set an upper limit at 0.69% at a 90% confidence level for the ratio of second- to first-class currents.