Low dose radiation hypersensitivity and clustered DNA damages in human fibroblasts exposed to low dose and dose rate protons or 137CS y-rays (open access)

Low dose radiation hypersensitivity and clustered DNA damages in human fibroblasts exposed to low dose and dose rate protons or 137CS y-rays

Effective radioprotection for human space travelers hinges upon understanding the individual properties of charged particles. A significant fraction of particle radiation astronauts will encounter in space exploratory missions will come from high energy protons in galactic cosmic radiation (GCR) and/or possible exposures to lower energy proton flux from solar particle events (SPEs). These potential exposures present major concerns for NASA and others, in planning and executing long term space exploratory missions. We recently reported cell survival and transformation (acquisition of anchorage-independent growth in soft agar) frequencies in apparently normal NFF-28 primary human fibroblasts exposed to 0-30 cGy of 50MeV, 100MeV (SPE-like), or 1000 MeV (GCR-like) monoenergetic protons. These were modeled after 1989 SPE energies at an SPE-like low dose-rate (LDR) of 1.65 cGy/min or high dose rate (HDR) of 33.3 cGy/min delivered at the NASA Space Radiation Laboratory (NSRL) at BNL.
Date: May 14, 2013
Creator: Bennett, P. V.; Keszenman, D. J.; Johnson, A. M.; Sutherland, B. M. & Wilson, P. F.
Object Type: Article
System: The UNT Digital Library
Lattice Quantum Chromodynamics (SPI, Mapping, Site Ordering, and QPX in Lattice QCD Code on Mira): ALCF-2 Early Science Program Technical Report (open access)

Lattice Quantum Chromodynamics (SPI, Mapping, Site Ordering, and QPX in Lattice QCD Code on Mira): ALCF-2 Early Science Program Technical Report

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Date: May 14, 2013
Creator: Na, H. & Osborn, J.
Object Type: Report
System: The UNT Digital Library
Direct Numerical Simulation of Autoignition in a Jet in a Cross-Flow Configuration: ALCF-2 Early Science Program Technical Report (open access)

Direct Numerical Simulation of Autoignition in a Jet in a Cross-Flow Configuration: ALCF-2 Early Science Program Technical Report

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Date: May 14, 2013
Creator: Abdilghanie, A.; Frouzakis, C.E. & Fischer, P. F.
Object Type: Report
System: The UNT Digital Library
Results For The First Quarter 2013 Tank 50 WAC Slurry Sample: Chemical And Radionuclide Contaminants (open access)

Results For The First Quarter 2013 Tank 50 WAC Slurry Sample: Chemical And Radionuclide Contaminants

This report details the chemical and radionuclide contaminant results for the characterization of the 2013 First Quarter sampling of Tank 50 for the Saltstone Waste Acceptance Criteria (WAC). Information from this characterization will be used by Waste Solidification Engineering (WSE) to support the transfer of low-level aqueous waste from Tank 50 to the Salt Feed Tank in the Saltstone Facility in Z-Area, where the waste will be immobilized. This information is also used to update the Tank 50 Waste Characterization System. The following conclusions are drawn from the analytical results provided in this report: SRR WAC targets or limits were met for all analyzed chemical and radioactive contaminates unless noted in this section; {sup 59}Ni, {sup 94}Nb, {sup 247}Cm, {sup 249}Cf, and {sup 251}Cf are above the requested SRR target concentrations. However, they are below the detection limits established by SRNL; Norpar 13 and Isopar L have higher detection limits compared with the Saltstone WAC. The data provided in this report is based upon the concentrations in the sub-sample, and due to the limited solubility in aqueous solution, may not represent the concentrations of the analytes in Tank 50; and, The low insoluble solids content increases the measurement uncertainty for …
Date: May 14, 2013
Creator: Bannochie, C. J.
Object Type: Report
System: The UNT Digital Library
Global Simulation of Plasma Microturbulence at the Petascale & Beyond (Optimizing the GTC Code for Blue Gene/Q): ALCF-2 Early Science Program Technical Report (open access)

Global Simulation of Plasma Microturbulence at the Petascale & Beyond (Optimizing the GTC Code for Blue Gene/Q): ALCF-2 Early Science Program Technical Report

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Date: May 14, 2013
Creator: Tang, William; Ethier, Stephane; Wang, Bei; Williams, Timothy; Ibrahim, Khaled; Madduri, Kamesh et al.
Object Type: Report
System: The UNT Digital Library
Materials Design and Discovery: Catalysis and Energy Storage (Mira Early Science Program Final Technical Report): ALCF-2 Early Science Program Technical Report (open access)

Materials Design and Discovery: Catalysis and Energy Storage (Mira Early Science Program Final Technical Report): ALCF-2 Early Science Program Technical Report

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Date: May 14, 2013
Creator: Benali, A. & Romero, N. A.
Object Type: Report
System: The UNT Digital Library
Feynman variance for neutrons emitted from photo-fission initiated fission chains - a systematic simulation for selected speacal nuclear materials (open access)

Feynman variance for neutrons emitted from photo-fission initiated fission chains - a systematic simulation for selected speacal nuclear materials

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Date: May 14, 2013
Creator: Soltz, R; Hartouni, E; Sheets, S & Glenn, A
Object Type: Report
System: The UNT Digital Library
Quantitative Analysis of Clustered DNA Damages Induced by Silicon Beams of Different Kinetic Energy (open access)

Quantitative Analysis of Clustered DNA Damages Induced by Silicon Beams of Different Kinetic Energy

Humans may b exposed to highly energetic charged particle radiation as a result of medical treatments, occupational activitie or accidental events. In recent years, our increasing presence and burgeoning interest in space exploration beyond low Earth orbit has led to a large increase in the research of the biological effects ofcharged particle radiation typical of that encountered in the space radiation environment. The study of the effects of these types of radiation qualities in terms ofDNA damage induction and repair is fundamental to understand mechanisms both underlying their greater biological effectiveness as we)) as the short and long term risks of health effects such as carcinogenesis, degen rative diseases and premature aging. Charged particle radiation induces a variety of DNA alterations, notably bistranded clustered damages, defined as two or more closely-opposed strand break , oxidized bases or abasic sites within a few helical turns. The induction of such highly complex DNA damage enhances the probability of incorrect or incomplete repair and thus constitutes greater potential for genomic instability, cell death and transformation.
Date: May 14, 2013
Creator: Keszenman, D. J.; Bennett, P. V.; Sutherland, B. M. & Wilson, P. F.
Object Type: Article
System: The UNT Digital Library