Article discussing the fluctuation-dissipation theorem for event-dominated processes.

Clostridium botulinum is a taxonomic designation for many diverse anaerobic spore forming rod-shaped bacteria which have the common property of producing botulinum neurotoxins (BoNTs). The BoNTs are exoneurotoxins that can cause severe paralysis and even death in humans and various other animal species. A collection of 174 C. botulinum strains were examined by amplified fragment length polymorphism (AFLP) analysis and by sequencing of the 16S rRNA gene and BoNT genes to examine genetic diversity within this species. This collection contained representatives of each of the seven different serotypes of botulinum neurotoxins (BoNT A-G). Analysis of the16S rRNA sequences confirmed earlier reports of at least four distinct genomic backgrounds (Groups I-IV) each of which has independently acquired one or more BoNT serotypes through horizontal gene transfer. AFLP analysis provided higher resolution, and can be used to further subdivide the four groups into sub-groups. Sequencing of the BoNT genes from serotypes A, B and E in multiple strains confirmed significant sequence variation within each serotype. Four distinct lineages within each of the BoNT A and B serotypes, and five distinct lineages of serotype E strains were identified. The nucleotide sequences of the seven serotypes of BoNT were compared and show varying degrees …

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The measurement of regional attenuation Q{sup -1} can produce method dependent results. The discrepancies among methods are due to differing parameterizations (e.g., geometrical spreading rates), employed datasets (e.g., choice of path lengths and sources), and methodologies themselves (e.g., measurement in the frequency or time domain). We apply the coda normalization (CN), two-station (TS), reverse two-station (RTS), source-pair/receiver-pair (SPRP), and the new coda-source normalization (CS) methods to measure Q of the regional phase, Lg (Q{sub Lg}), and its power-law dependence on frequency of the form Q{sub 0}f{sup {eta}} with controlled parameterization in the well-studied region of northern California using a high-quality dataset from the Berkeley Digital Seismic Network. We test the sensitivity of each method to changes in geometrical spreading, Lg frequency bandwidth, the distance range of data, and the Lg measurement window. For a given method, there are significant differences in the power-law parameters, Q{sub 0} and {eta}, due to perturbations in the parameterization when evaluated using a conservative pairwise comparison. The CN method is affected most by changes in the distance range, which is most probably due to its fixed coda measurement window. Since, the CS method is best used to calculate the total path attenuation, it is very …

Using a regional time-domain waveform inversion for the complete moment tensor we calculate the deviatoric and isotropic source components for several explosions at the Nevada Test Site as well as earthquakes, and collapses in the surrounding region of the western US. The events separate into specific populations according to their deviation from a pure double-couple and ratio of isotropic to deviatoric energy. The separation allows for anomalous event identification and discrimination between explosions, earthquakes, and collapses. Error in the moment tensor solutions and source parameters is also calculated. We investigate the sensitivity of the moment tensor solutions to Green's functions calculated with imperfect Earth models, inaccurate event locations, and data with a low signal-to-noise ratio. We also test the performance of the method under a range of recording conditions from excellent azimuthal coverage to cases of sparse station availability, as might be expected for smaller events. Finally, we assess the depth and frequency dependence upon event size. This analysis will be used to determine the range where well-constrained solutions can be obtained.

This report describes a cold mass support system based on the use of oriented fiberglassepoxy rods in bending.

A double-windowed vacuum-tight experimental chamber was developed, and calibrated on the spectroscopic ellipsometer over the energy range from .7 to 4.5 eV using a silicon wafer with approximately 25 nm oxide thickness to remove the multiple-window effects from measurements. The ellipsometric measurements were done such that incident and exit beam were at 65 degree from surface normal. The plutonium sample (3 mm diameter, .1 mm thick) was electro-polished and mounted into the sample chamber in a glove box having a nitrogen atmosphere with less than 100ppm moisture and oxygen content. The index of refraction n and the extinction coefficient k decrease from 3.7 to 1 and 5.5 to 1.1 respectively as the photon energy increases from .7 to 4.3 eV.

Genomic comparisons between human and distant, non-primatemammals are commonly used to identify cis-regulatory elements based onconstrained sequence evolution. However, these methods fail to detect"cryptic" functional elements, which are too weakly conserved amongmammals to distinguish from nonfunctional DNA. To address this problem,we explored the potential of deep intra-primate sequence comparisons. Wesequenced the orthologs of 558 kb of human genomic sequence, coveringmultiple loci involved in cholesterol homeostasis, in 6 nonhumanprimates. Our analysis identified 6 noncoding DNA elements displayingsignificant conservation among primates, but undetectable in more distantcomparisons. In vitro and in vivo tests revealed that at least three ofthese 6 elements have regulatory function. Notably, the mouse orthologsof these three functional human sequences had regulatory activity despitetheir lack of significant sequence conservation, indicating that they arecryptic ancestral cis-regulatory elements. These regulatory elementscould still be detected in a smaller set of three primate speciesincluding human, rhesus and marmoset. Since the human and rhesus genomesequences are already available, and the marmoset genome is activelybeing sequenced, the primate-specific conservation analysis describedhere can be applied in the near future on a whole-genome scale, tocomplement the annotation provided by more distant speciescomparisons.

Recent experiments on double photoionization of H$_2$ with photon energies between 160 and 240 eV have revealed body-frame angular distributions that suggest classical two-slit interference effects may be present when one electron carries most of the available energy and the second electron is not observed. We report precise quantum mechanical calculations that reproduce the experimental findings. They reveal that the interpretation in terms of classical diffraction is only appropriate atsubstantially higher photon energies. At the energies considered in the experiment we offer an alternative explanation based on the mixing of two non-diffractive contributions by circularly polarized light.

The National Nuclear Security Administration (NNSA) Ground-Based Nuclear Explosion Monitoring Research and Engineering (GNEM R&E) Program at LLNL has made significant progress enhancing the process of deriving seismic calibrations and performing scientific integration, analysis, and information management with software automation tools. Several achievements in schema design, data visualization, synthesis, and analysis were completed this year. Our tool efforts address the problematic issues of very large datasets and varied formats encountered during seismic calibration research. As data volumes have increased, scientific information management issues such as data quality assessment, ontology mapping, and metadata collection that are essential for production and validation of derived calibrations have negatively impacted researchers abilities to produce products. New information management and analysis tools have resulted in demonstrated gains in efficiency of producing scientific data products and improved accuracy of derived seismic calibrations. Significant software engineering and development efforts have produced an object-oriented framework that provides database centric coordination between scientific tools, users, and data. Nearly a half billion parameters, signals, measurements, and metadata entries are all stored in a relational database accessed by an extensive object-oriented multi-technology software framework that includes elements of stored procedures, real-time transactional database triggers and constraints, as well as coupled Java …

We measure the time to explosion of 12.7 mm diameter spheres of ultra fine TATB and PBX-9502 (95 wt% TATB, 5 wt% Kel-F 800) at 85.0, 92.5, and 98.0 percent of theoretical maximum density (TMD) in confined and unconfined configurations and at several elevated temperatures with the Lawrence Livermore National Laboratory (LLNL) One Dimensional Time to Explosion (ODTX) apparatus. Time to explosion data provide insight into the relative ease of thermal ignition and allow for the calibration of kinetic parameters. The measurements show that PBX-9502 is more thermally stable than ultra fine TATB, that unconfined samples are slightly more thermally stable than confined ones, and that lower density samples are more thermally stable than higher density ones. 'Go/no go' data at the lowest temperatures yield an experimental measurement of the critical temperature, which is the temperature at which an explosive can be heated indefinitely without undergoing self-heating and concomitant rapid and violent decomposition. Critical temperatures ranges for 12.7 mm diameter spheres of 98% TMD ultra fine TATB and PBX-9502 are 213-230 C and 234-239 C, respectively. Experimental data are modeled with ALE3D and kinetic parameters are determined. These kinetic parameters, when coupled with thermal property data, provide good prediction of …

This review article surveys recent work on computer representation of molecular surfaces. Several different algorithms are discussed for producing vector or raster drawings of space-filling models formed as the union of spheres. Other smoother surfaces are also considered.

Recent Supreme Court decisions, which interpret the 200-year-old Fourth Amendment of the US Constitution, are used to provide a brief overview of some search and seizure subjects important to management and officers responsible for physical protection of nuclear facilities. The overview is framed in practical terms in order to make the comments applicable to the everyday activity of nuclear-protective-force persons. The Supreme Court has described several exceptions where searches and seizures (arrests) are permitted without a warrant, despite the Fourth Amendment which states that warrants are always required. The seven exceptions briefly discussed are search incidents to a lawful arrest, the automobile-search exception, the suitcase or container exception, the hot-pursuit or emergency exception, the stop-and-frisk exception, the plain-view exception, and consent to be searched.

The steam-driven GKSS pressure suppression test facility, which contains 3 full scale vent pipes, has been used for 5 years to investigate the postulated loss-of-coolant accident in a Mark II and Type 69 boiling water reactor. Using the results from several of these tests, wetwell boundary load data (peak pressures and spectral power) during the chugging stage, have been evaluated for sparse pool response (one and two vents in the three vent pool) and for full pool response (one, two, or three vent operation in pools of constant wetwell pool area per vent). The sparse pool results indicate the pool-system, chug event boundary loads are strongly dependent on wetwell pool area per vent, with the load increasing with decreasing area. The full pool results show a substantial increase in the pool-system, chug event boundary loads upon a change from single cell to double cell operation; only minor change occurs in going from double to triple cell operation.

The 242-A Evaporator is the primary waste evaporator for the Hanford Site radioactive liquid waste stored in underground double-shell tanks. Low pressure evaporation is used to remove water from the waste, thus reducing the amount of tank space required for storage. The process produces a concentrated slurry, a process condensate, and an offgas. The offgas exhausts through two stages of high-efficiency particulate air (HEPA) filters before being discharged to the atmosphere 40 CFR 61 Subpart H requires assessment of the unfiltered exhaust to determine if continuous compliant sampling is required. Because potential (unfiltered) emissions are not measured, methods have been developed to estimate these emissions. One of the methods accepted by the Environmental Protection Agency is the measurement of the accumulation of radionuclides on the HEPA filters. Nondestructive assay (NDA) was selected for determining the accumulation on the HEPA filters. NDA was performed on the HEPA filters before and after a campaign in 1997. NDA results indicate that 2.1 E+4 becquerels of cesium-137 were accumulated on the primary HEPA 1700 filter during the campaign. The feed material processed in the campaign contained a total of 1.4 E+l6 Bq of cesium-137. The release factor for the evaporator process is 1.5 E-12. …

Subcooled flow of liquid nitrogen in microchannels is proposed as a means to enhance the stability of a superconducting magnet. Analysis shows high current density or a low stabilizer fraction is obtainable in a cryostable magnet. Increase in stability (using the Stekley criterion) is directly related to coolant velocity and coolant channel aspect ratio, however, there is a corresponding increase in pressure drop of the system. Another constraint is the coolant temperature rise, which is found to be a function of coolant residence time and the coolant to conductor ratio.

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We propose a novel triple modulator-chicane (TMC) scheme to convert external input seed to shorter wavelengths. In the scheme high power seed lasers are used in the first and third modulator while only very low power seed is used in the second modulator. By properly choosing the parameters of the lasers and chicanes, we show that ultrahigh harmonics can be generated in the TMC scheme while simultaneously keeping the energy spread growth much smaller than beam's initial slice energy spread. As an example we show the feasibility of generating significant bunching at 1 nm and below from a low power ({approx} 100 kW) high harmonic generation seed at 20 nm assisted by two high power ({approx} 100 MW) UV lasers at 200 nm while keeping the energy spread growth within 40%. The supreme up-frequency conversion efficiency of the proposed TMC scheme together with its unique advantage in maintaining beam energy spread opens new opportunities for generating fully coherent x-rays at sub-nanometer wavelength from external seeds.

The Large Synoptic Survey Telescope (LSST) will continuously image the entire sky visible from Cerro Pachon in northern Chile every 3-4 nights throughout the year. The LSST will provide data for a broad range of science investigations that require better than 1% photometric precision across the sky (repeatability and uniformity) and a similar accuracy of measured broadband color. The fast and persistent cadence of the LSST survey will significantly improve the temporal sampling rate with which celestial events and motions are tracked. To achieve these goals, and to optimally utilize the observing calendar, it will be necessary to obtain excellent photometric calibration of data taken over a wide range of observing conditions - even those not normally considered 'photometric'. To achieve this it will be necessary to routinely and accurately measure the full optical passband that includes the atmosphere as well as the instrumental telescope and camera system. The LSST mountain facility will include a new monochromatic dome illumination projector system to measure the detailed wavelength dependence of the instrumental passband for each channel in the system. The facility will also include an auxiliary spectroscopic telescope dedicated to measurement of atmospheric transparency at all locations in the sky during LSST …

Short single-stranded nucleic acids are ubiquitous in biological processes and understanding their physical properties provides insights to nucleic acid folding and dynamics. We used small angle x-ray scattering to study 8-100 residue homopolymeric single-stranded DNAs in solution, without external forces or labeling probes. Poly-T's structural ensemble changes with increasing ionic strength in a manner consistent with a polyelectrolyte persistence length theory that accounts for molecular flexibility. For any number of residues, poly-A is consistently more elongated than poly-T, likely due to the tendency of A residues to form stronger base-stacking interactions than T residues.

Attribute Measurement Systems have been developed and demonstrated several times in the United States over the last decade or so; under the Trilateral Initiative (1996-2002), FMTTD (Fissile Material Transparency Technology Demonstration, 2000), and NG-AMS (Next Generation Attribute Measurement System, 2005-2008). Each Attribute Measurement System has contributed to the growing body of knowledge regarding the use of such systems in warhead dismantlement and other Arms Control scenarios. The Trilateral Initiative, besides developing prototype hardware/software, introduced the topic to the international community. The 'trilateral' parties included the United States, the Russian Federation, and the International Atomic Energy Agency (IAEA). With the participation of a Russian delegation, the FMTTD demonstrated that measurements behind an information barrier are feasible while meeting host party security requirements. The NG-AMS system explored the consequences of maximizing the use of Commercial off the Shelf (COTS) equipment, which made construction easier, but authentication harder. The 3rd Generation Attribute Measurement System (3G-AMS) will further the scope of previous systems by including additional attributes and more rigor in authentication.

Recent progress at the SPEAR3 includes the increase in stored current from 100 mA to 200 mA and top-off injection to allow beamlines to stay open during injection. Presently the booster injects 3.0 GeV beam to SPEAR3 three times a day. The stored beam decays to about 150 mA between the injections. The growing user demands are to increase the stored current to the design value of 500 mA, and to maintain it at a constant value within a percent or so. To achieve this goal the booster must inject once every few minutes. For improved injection efficiency, all RF systems at the linac, booster and SPEAR3 need to be phase-locked. The present booster RF system is basically a copy of the SPEAR2 RF system with 358.5 MHz and 40 kW peak RF power driving a 5-cell RF cavity for 1.0 MV gap voltage. These requirements entail a booster RF system upgrade to a scaled down version of the SPEAR3 RF system of 476.3 MHz with 1.2 MW cw klystron output power capabilities. We will analyze each subsystem option for their merits within budgetary and geometric space constraints. A substantial portion of the system will come from the decommissioned PEP-II …

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The capture of solar energy by photosynthesis has had a most profound influence on the development and sustenance of life on earth. It is the engine that has driven the proliferation of life and, as the source of both energy and oxygen, has had a major hand in shaping the forms that life has taken. Both ancient and present day photosynthetic carbon fixation is intimately tied to issues of immediate human concern, global energy and global warming. Decreasing our reliance on fossil fuels by tapping photosynthesis in a more direct way is an attractive goal for sustainable energy. Meeting this challenge means understanding photosynthetic energy conversion at a molecular level, a task requiring perspectives ranging through all disciplines of science. Researchers in photosynthesis have a strong history of working across conventional boundaries and engaging in multidisciplinary collaborations. The Gordon conference in photosynthesis has been a key focal point for the dissemination of new results and the establishment of powerful research collaborations. In this spirit the 2009 Gordon conference on biophysical aspects of photosynthesis will bring together top international researchers from diverse and complementary disciplines, all working towards understanding how photosynthesis converts light into the stable chemical energy that powers so …