The 2010 GRC on Mitochondria & Chloroplasts will assemble an international group of molecular, structural and cellular biologists, biochemists and geneticists investigating a broad spectrum of fundamental problems related to the biology of these organelles in animal, plant and fungal cells. This field has witnessed an extraordinary expansion in recent years, fueled by the discovery of the role of mitochondria in human disease and ageing, and of the synergy of chloroplasts and mitochondria in energetic output, the identification of novel factors involved in organelle division, movement, signaling and acclimation to changing environmental conditions, and by the powerful tools of organelle proteomics. The 2010 GRC will highlight advances in the elucidation of molecular mechanisms of organelle biogenesis including regulation of genome structure, evolution and expression, organellar protein import, assembly and turnover of respiratory and photosynthetic complexes, bidirectional signaling between organelles and nucleus, organelle morphology and dynamics, and the integration of cellular metabolism. We will also explore progress in mechanisms of disease and ageing/ senescence in animals and plants. The organellar field has forged new fronts toward a global and comprehensive understanding of mitochondrial and chloroplast biology at the molecular level. Many of the molecules under study in model organisms are responsible …

The Savannah River National Laboratory has developed a 'hybrid' approach to Performance Assessment modeling which has been used for a number of Performance Assessments. This hybrid approach uses a multi-dimensional modeling platform (PorFlow) to develop deterministic flow fields and perform contaminant transport. The GoldSim modeling platform is used to develop the Sensitivity and Uncertainty analyses. Because these codes are performing complementary tasks, it is incumbent upon them that for the deterministic cases they produce very similar results. This paper discusses two very different waste forms, one with no engineered barriers and one with engineered barriers, each of which present different challenges to the abstraction of data. The hybrid approach to Performance Assessment modeling used at the SRNL uses a 2-D unsaturated zone (UZ) and a 3-D saturated zone (SZ) model in the PorFlow modeling platform. The UZ model consists of the waste zone and the unsaturated zoned between the waste zone and the water table. The SZ model consists of source cells beneath the waste form to the points of interest. Both models contain 'buffer' cells so that modeling domain boundaries do not adversely affect the calculation. The information pipeline between the two models is the contaminant flux. The domain …

Article on the U.S. National Science Foundation's (NSF) Broader Impacts Merit Review Criterion in relation to the America COMPETES Reauthorization Act of 2010.

We report the design and current status of a monoenergetic laser-based Compton scattering 0.5-2.5 MeV {gamma}-ray source. Previous nuclear resonance fluorescence results and future linac and laser developments for the source are presented. At MeV photon energies relevant for nuclear processes, Compton scattering light sources are attractive because of their relative compactness and improved brightness above 100 keV, compared to typical 4th generation synchrotrons. Recent progress in accelerator physics and laser technology have enabled the development of a new class of tunable Mono-Energetic Gamma-Ray (MEGa-Ray) light sources based on Compton scattering between a high-brightness, relativistic electron beam and a high intensity laser pulse produced via chirped-pulse amplification (CPA). A new precision, tunable gamma-ray source driven by a compact, high-gradient X-band linac is currently under development and construction at LLNL. High-brightness, relativistic electron bunches produced by an X-band linac designed in collaboration with SLAC will interact with a Joule-class, 10 ps, diode-pumped CPA laser pulse to generate tunable {gamma}-rays in the 0.5-2.5 MeV photon energy range via Compton scattering. Based on the success of the previous Thomson-Radiated Extreme X-rays (T-REX) Compton scattering source at LLNL, the source will be used to excite nuclear resonance fluorescence lines in various isotopes; applications include …

In this present work, the affects of different transition metal halides (TiCl{sub 3}, VCl{sub 3}, ScCl{sub 3} and NiCl{sub 2}) on the sorption properties of the 1:1 molar ratio of LiNH{sub 2} to MgH{sub 2} are investigated. The modified mixtures were found to contain LiNH{sub 2}, MgH{sub 2} and LiCl. TGA results showed that the hydrogen desorption temperature was reduced with the modifier addition in this order: TiCl{sub 3}>ScCl{sub 3}>VCl{sub 3}>NiCl{sub 2}. Ammonia release was not significantly reduced resulting in a weight loss greater than the theoretical hydrogen storage capacity of the material. The isothermal sorption kinetics of the modified systems showed little improvement after the first dehydrogenation cycle over the unmodified system but showed drastic improvement in rehydrogenation cycles. XRD and Raman spectroscopy identified the cycled material to be composed of LiH, MgH{sub 2}, Mg(NH{sub 2}){sub 2} and Mg{sub 3}N{sub 2}.

Adoption of information and communication technologies and access to the Internet is expanding in Africa, but because of the rapid growth elsewhere, a Digital Divide between Africa and the rest of the world exists, and the gap is growing. In many sub-Saharan African countries, education and research sector suffers some of the worst deficiencies in access to the Internet, despite progress in development of NRENs - National Research and Education (cyber) Networks. By contrast, it is widely acknowledged in policy statements from the African Union, the UN, and others that strength in this very sector provides the key to meeting and sustaining Millennium Development Goals. Developed countries with effective cyber-capabilities proclaim the benefits to rich and poor alike arising from the Information Revolution. This is but a dream for many scientists in African institutions. As the world of science becomes increasingly Internet-dependent, so they become increasingly isolated. eGY-Africa is a bottom-up initiative by African scientists and their collaborators to try to reduce this Digital Divide by a campaign of advocacy for better institutional facilities. Four approaches are being taken. The present status of Internet services, problems, and plans are being mapped via a combination of direct measurement of Internet performance …

Studies of nuclear resonance fluorescence based applications are presented. Important for these applications are data for isotopes such as {sup 239}Pu. Nuclear resonance fluorescence measurements of {sup 239}Pu were performed at the free electron laser facility at UC Santa Barbara using photons from a bremsstrahlung beam with an endpoint energies between 4.0 MeV and 5.5 MeV. Though no discrete states with significant confidence level were measured, we have excluded the region above 27(3) eV-barns, or 4-sigma, where we would expect only a small chance of false positives. Details of the measurements and the results are presented here.

The recent Quantum Hall experiments in graphene have confirmed the theoretically well-understood picture of the quantum Hall (QH) conductance in fermion systems with continuum Dirac spectrum. In this paper we take into account the lattice, and perform an exact diagonalization of the Landau problem on the hexagonal lattice. At very large magnetic fields the Dirac argument fails completely and the Hall conductance, given by the number of edge states present in the gaps of the spectrum, is dominated by lattice effects. As the field is lowered, the experimentally observed situation is recovered through a phenomenon which we call band collapse. As a corollary, for low magnetic field, graphene will exhibit two qualitatively different QHE's: at low filling, the QHE will be dominated by the 'relativistic' Dirac spectrum and the Hall conductance will be odd-integer; above a certain filling, the QHE will be dominated by a non-relativistic spectrum, and the Hall conductance will span all integers, even and odd.

We present a study of the D{sup +}{pi}{sup -}, D{sup 0}{pi}{sup +}, and D*{sup +}{pi}{sup -} systems in inclusive e{sup +}e{sup -} {yields} c{bar c} interactions in a search for new excited D meson states. We use a dataset, consisting of {approx}454 fb{sup -1}, collected at center-of-mass energies near 10.58 GeV by the BABAR detector at the SLAC PEP-II asymmetric-energy collider. We observe, for the first time, candidates for the radial excitations of the D{sup 0}, D*{sup 0}, and D*{sup +}, as well as the L = 2 excited states of the D{sup 0} and D{sup +}, where L is the orbital angular momentum of the quarks.

The EXAFS spectra of Cu and Pd foil from many different beamlines and synchrotrons are compared to address the dependence of the amplitude reduction factor (S{sub 0}{sup 2}) on beamline specific parameters. Even though S{sub 0}{sup 2} is the same parameter as the EXAFS coordination number, the value for S{sub 0}{sup 2} is given little attention, and is often unreported. The S{sub 0}{sup 2} often differs for the same material due to beamline and sample attributes, such that no importance is given to S{sub 0}{sup 2}-values within a general range of 0.7 to 1.1. EXAFS beamlines have evolved such that it should now be feasible to use standard S{sub 0}{sup 2} values for all EXAFS measurements of a specific elemental environment. This would allow for the determination of the imaginary energy (Ei) to account for broadening of the EXAFS signal rather than folding these errors into an effective S{sub 0}{sup 2}-value. To test this concept, we model 11 Cu-foil and 6 Pd-foil EXAFS spectra from around the world to compare the difference in S{sub 0}{sup 2}- and Ei-values.

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The fragile structure of chondritic-porous interplanetary dust particles (CP-IDPs) and their minimal parent-body alteration have led researchers to believe these particles originate in comets rather than asteroids where aqueous and thermal alterations have occurred. The solar elemental abundances and atmospheric entry speed of CP-IDPs also suggest a cometary origin. With the return of the Stardust samples from Jupiter-family comet 81P/Wild 2, this hypothesis can be tested. We have measured the Fe oxidation state of 15 CP-IDPs and 194 Stardust fragments using a synchrotron-based x-ray microprobe. We analyzed {approx}300 ng of Wild 2 material - three orders of magnitude more material than other analyses comparing Wild 2 and CP-IDPs. The Fe oxidation state of these two samples of material are > 2{sigma} different: the CP-IDPs are more oxidized than the Wild 2 grains. We conclude that comet Wild 2 contains material that formed at a lower oxygen fugacity than the parent-body, or parent bodies, of CP-IDPs. If all Jupiter-family comets are similar, they do not appear to be consistent with the origin of CP-IDPs. However, comets that formed from a different mix of nebular material and are more oxidized than Wild 2 could be the source of CP-IDPs.

This paper presents the summary of design features and test results of two Type B Shipping Package prototype configurations comprising different insulating materials developed by the Savannah River National Laboratory (SRNL) for the Department of Energy. The materials evaluated, a closed-cell polyurethane foam and a vacuformed ceramic fiber material, were selected to provide adequate structural protection to the package containment vessel during Normal Conditions of Transport (NCT) and Hypothetical Accident Condition (HAC) events and to provide thermal protection during the HAC fire. Polyurethane foam has been used in shipping package designs for many years because of the stiffness it provides to the structure and because of the thermal protection it provides during fire scenarios. This comparison describes how ceramic fiber material offers an alternative to the polyurethane foam in a specific overpack design. Because of the high operating temperature ({approx}2,300 F) of the ceramic material, it allows for contents with higher heat loads to be shipped than is possible with polyurethane foam. Methods of manufacturing and design considerations using the two materials will be addressed.

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Environmental statistics provide a necessary means of comparing the properties of galaxies in different environments and a vital test of models of galaxy formation within the prevailing, hierarchical cosmological model. We explore counts-in-cylinders, a common statistic defined as the number of companions of a particular galaxy found within a given projected radius and redshift interval. Galaxy distributions with the same two-point correlation functions do not necessarily have the same companion count distributions. We use this statistic to examine the environments of galaxies in the Sloan Digital Sky Survey, Data Release 4. We also make preliminary comparisons to four models for the spatial distributions of galaxies, based on N-body simulations, and data from SDSS DR4 to study the utility of the counts-in-cylinders statistic. There is a very large scatter between the number of companions a galaxy has and the mass of its parent dark matter halo and the halo occupation, limiting the utility of this statistic for certain kinds of environmental studies. We also show that prevalent, empirical models of galaxy clustering that match observed two- and three-point clustering statistics well fail to reproduce some aspects of the observed distribution of counts-in-cylinders on 1, 3 and 6-h{sup -1}Mpc scales. All models …

Five parameters were evaluated with surrogates of Bacillus anthracis spores to determine effective decontamination options for use in a contaminated drinking water supply. The parameters were: (1) type of Bacillus spore surrogate (B. thuringiensis or B. atrophaeus); (2) spore concentration in suspension (10{sup 2} to 10{sup 6} spores/ml); (3) chemical characteristics of decontaminant [sodium dicholor-s-triazinetrione dihydrate (Dichlor), hydrogen peroxide, potassium peroxymonosulfate (Oxone), sodium hypochlorite, and VirkonS{reg_sign}]; (4) decontaminant concentration (0.01% to 5%); and (5) decontaminant exposure time (10 min to 24 hr). Results from 162 suspension tests with appropriate controls are reported. Hydrogen peroxide at a concentration of 5%, and Dichlor and sodium hypochlorite at a concentration of 2%, were effective at spore inactivation regardless of spore type tested, spore exposure time, or spore concentration evaluated. This is the first reported study of Dichlor as an effective decontaminant for B. anthracis spore surrogates. Dichlor's desirable characteristics of high oxidation potential, high level of free chlorine, and more neutral pH than that of other oxidizers evaluated appear to make it an excellent alternative. All three oxidizers were effective against B. atrophaeus spores in meeting EPA's biocide standard of greater than a 6 log kill after a 10-minute exposure time and at …

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A collaboration, including all DOE synchrotron labs, industrial vendors of x-ray optics, and with active participation of the HBZ-BESSY-II optics group has been established to work together on a new slope measuring profiler -- the optical slope measuring system (OSMS). The slope measurement accuracy of the instrument is expected to be<50 nrad for the current and future metrology of x-ray optics for the next generation of light sources. The goals were to solidify a design that meets the needs of mirror specifications and also be affordable; and to create a common specification for fabrication of a multi-functional translation/scanning (MFTS) system for the OSMS. This was accomplished by two collaborative meetings at the ALS (March 26, 2010) and at the APS (May 6, 2010).

An important diagnostic tool for inertial confinement fusion will be time-resolved radiographic imaging of the dense cold fuel surrounding the hot spot. The measurement technique is based on point-projection radiography at photon energies from 60-200 keV where the Compton effect is the dominant contributor to the opacity of the fuel or pusher. We have successfully applied this novel Compton Radiography technique to the study of the final compression of directly driven plastic capsules at the OMEGA facility. The radiographs have a spatial and temporal resolution of {approx}10 {micro}m and {approx}10ps, respectively. A statistical accuracy of {approx}0.5% in transmission per resolution element is achieved, allowing localized measurements of areal mass densities to 7% accuracy. The experimental results show 3D non-uniformities and lower than 1D expected areal densities attributed to drive asymmetries and hydroinstabilities.

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The reaction of the ground state methylidyne radical CH (X2Pi) with pyrrole (C4H5N) has been studied in a slow flow tube reactor using Multiplexed Photoionization Mass Spectrometry coupled to quasi-continuous tunable VUV synchrotron radiation at room temperature (295 K) and 90 oC (363 K), at 4 Torr (533 Pa). Laser photolysis of bromoform (CHBr3) at 248 nm (KrF excimer laser) is used to produce CH radicals that are free to react with pyrrole molecules in the gaseous mixture. A signal at m/z = 79 (C5H5N) is identified as the product of the reaction and resolved from 79Br atoms, and the result is consistent with CH addition to pyrrole followed by Helimination. The Photoionization Efficiency curve unambiguously identifies m/z = 79 as pyridine. With deuterated methylidyne radicals (CD), the product mass peak is shifted by +1 mass unit, consistent with the formation of C5H4DN and identified as deuterated pyridine (dpyridine). Within detection limits, there is no evidence that the addition intermediate complex undergoes hydrogen scrambling. The results are consistent with a reaction mechanism that proceeds via the direct CH (CD) cycloaddition or insertion into the five-member pyrrole ring, giving rise to ring expansion, followed by H atom elimination from the nitrogen …

This paper reviews the status of direct-drive inertial confinement fusion (ICF) research at the University of Rochester's Laboratory for Laser Energetics (LLE). LLE's goal is to demonstrate direct-drive ignition on the National Ignition Facility (NIF) by 2014. Baseline "all-DT" NIF direct-drive ignition target designs have been developed that have a predicted gain of 45 (1-D) at a NIF drive energy of ~1.6 MJ. Significantly higher gains are calculated for targets that include a DT-wicked foam ablator. This paper also reviews the results of both warm fuel and initial cryogenic-fuel spherical target implosion experiments carried out on the OMEGA UV laser. The results of these experiments and design calculations increase confidence that the NIF direct-drive ICF ignition goal will be achieved.

For a given symmetric positive definite matrix A {element_of} R{sup N x N}, we develop a fast and backward stable algorithm to approximate A by a symmetric positive-definite semi-separable matrix, accurate to a constant multiple of any prescribed tolerance. In addition, this algorithm preserves the product, AZ, for a given matrix Z {element_of} R{sup N x d}, where d << N. Our algorithm guarantees the positive-definiteness of the semi-separable matrix by embedding an approximation strategy inside a Cholesky factorization procedure to ensure that the Schur complements during the Cholesky factorization all remain positive definite after approximation. It uses a robust direction-preserving approximation scheme to ensure the preservation of AZ. We present numerical experiments and discuss potential implications of our work.