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Sample records for radiation signatures progress

  1. Infrared Signature Masking by Air Plasma Radiation

    NASA Technical Reports Server (NTRS)

    Kruger, C. H.; Laux, C. O.

    1998-01-01

    This report describes progress during the second year of our research program on Infrared Signature Masking by Air Plasmas at Stanford University. This program is intended to investigate the masking of infrared signatures by the air plasma formed behind the bow shock of high velocity missiles. Our previous annual report described spectral measurements and modeling of the radiation emitted between 3.2 and 5.5 microns by an atmospheric pressure air plasma in chemical and thermal equilibrium at a temperature of approximately 3100 K. One of our goals was to examine the spectral emission of secondary species such as water vapor or carbon dioxide. The cold air stream injected in the plasma torch contained approximately 330 parts per million Of CO2, which is the natural CO2 concentration in atmospheric air at room temperature, and a small amount of water vapor with an estimated mole fraction of 3.8 x 10(exp -4). As can be seen from Figure 1, it was found that the measured spectrum exhibited intense spectral features due to the fundamental rovibrational bands of NO at 4.9 - 5.5 microns and the V(3) band of CO2 (antisymmetric stretch) at 4.2-4.8 microns. These observations confirmed the well-known fact that infrared signatures between 4.15 - 5.5 microns can be masked by radiative emission in the interceptor's bow-shock. Figure I also suggested that the range 3.2 - 4.15 microns did not contain any significant emission features (lines or continuum) that could mask IR signatures. However, the signal-to-noise level, close to one in that range, precluded definite conclusions. Thus, in an effort to further investigate the spectral emission in the range of interest to signature masking problem, new measurements were made with a higher signal-to-noise ratio and an extended wavelength range.

  2. A Methodology for Calculating Radiation Signatures

    SciTech Connect

    Klasky, Marc Louis; Wilcox, Trevor; Bathke, Charles G.; James, Michael R.

    2015-05-01

    A rigorous formalism is presented for calculating radiation signatures from both Special Nuclear Material (SNM) as well as radiological sources. The use of MCNP6 in conjunction with CINDER/ORIGEN is described to allow for the determination of both neutron and photon leakages from objects of interest. In addition, a description of the use of MCNP6 to properly model the background neutron and photon sources is also presented. Examinations of the physics issues encountered in the modeling are investigated so as to allow for guidance in the user discerning the relevant physics to incorporate into general radiation signature calculations. Furthermore, examples are provided to assist in delineating the pertinent physics that must be accounted for. Finally, examples of detector modeling utilizing MCNP are provided along with a discussion on the generation of Receiver Operating Curves, which are the suggested means by which to determine detectability radiation signatures emanating from objects.

  3. The radiative signature of upper tropospheric moistening.

    PubMed

    Soden, Brian J; Jackson, Darren L; Ramaswamy, V; Schwarzkopf, M D; Huang, Xianglei

    2005-11-01

    Climate models predict that the concentration of water vapor in the upper troposphere could double by the end of the century as a result of increases in greenhouse gases. Such moistening plays a key role in amplifying the rate at which the climate warms in response to anthropogenic activities, but has been difficult to detect because of deficiencies in conventional observing systems. We use satellite measurements to highlight a distinct radiative signature of upper tropospheric moistening over the period 1982 to 2004. The observed moistening is accurately captured by climate model simulations and lends further credence to model projections of future global warming. PMID:16210499

  4. Mutational signatures of ionizing radiation in second malignancies.

    PubMed

    Behjati, Sam; Gundem, Gunes; Wedge, David C; Roberts, Nicola D; Tarpey, Patrick S; Cooke, Susanna L; Van Loo, Peter; Alexandrov, Ludmil B; Ramakrishna, Manasa; Davies, Helen; Nik-Zainal, Serena; Hardy, Claire; Latimer, Calli; Raine, Keiran M; Stebbings, Lucy; Menzies, Andy; Jones, David; Shepherd, Rebecca; Butler, Adam P; Teague, Jon W; Jorgensen, Mette; Khatri, Bhavisha; Pillay, Nischalan; Shlien, Adam; Futreal, P Andrew; Badie, Christophe; McDermott, Ultan; Bova, G Steven; Richardson, Andrea L; Flanagan, Adrienne M; Stratton, Michael R; Campbell, Peter J

    2016-01-01

    Ionizing radiation is a potent carcinogen, inducing cancer through DNA damage. The signatures of mutations arising in human tissues following in vivo exposure to ionizing radiation have not been documented. Here, we searched for signatures of ionizing radiation in 12 radiation-associated second malignancies of different tumour types. Two signatures of somatic mutation characterize ionizing radiation exposure irrespective of tumour type. Compared with 319 radiation-naive tumours, radiation-associated tumours carry a median extra 201 deletions genome-wide, sized 1-100 base pairs often with microhomology at the junction. Unlike deletions of radiation-naive tumours, these show no variation in density across the genome or correlation with sequence context, replication timing or chromatin structure. Furthermore, we observe a significant increase in balanced inversions in radiation-associated tumours. Both small deletions and inversions generate driver mutations. Thus, ionizing radiation generates distinctive mutational signatures that explain its carcinogenic potential. PMID:27615322

  5. Integrative Metabolic Signatures for Hepatic Radiation Injury

    PubMed Central

    Su, Gang; Meng, Fan; Liu, Laibin; Mohney, Robert; Kulkarni, Shilpa; Guha, Chandan

    2015-01-01

    Background Radiation-induced liver disease (RILD) is a dose-limiting factor in curative radiation therapy (RT) for liver cancers, making early detection of radiation-associated liver injury absolutely essential for medical intervention. A metabolomic approach was used to determine metabolic signatures that could serve as biomarkers for early detection of RILD in mice. Methods Anesthetized C57BL/6 mice received 0, 10 or 50 Gy Whole Liver Irradiation (WLI) and were contrasted to mice, which received 10 Gy whole body irradiation (WBI). Liver and plasma samples were collected at 24 hours after irradiation. The samples were processed using Gas Chromatography/Mass Spectrometry and Liquid Chromatography/Mass Spectrometry. Results Twenty four hours after WLI, 407 metabolites were detected in liver samples while 347 metabolites were detected in plasma. Plasma metabolites associated with 50 Gy WLI included several amino acids, purine and pyrimidine metabolites, microbial metabolites, and most prominently bradykinin and 3-indoxyl-sulfate. Liver metabolites associated with 50 Gy WLI included pentose phosphate, purine, and pyrimidine metabolites in liver. Plasma biomarkers in common between WLI and WBI were enriched in microbial metabolites such as 3 indoxyl sulfate, indole-3-lactic acid, phenyllactic acid, pipecolic acid, hippuric acid, and markers of DNA damage such as 2-deoxyuridine. Metabolites associated with tryptophan and indoles may reflect radiation-induced gut microbiome effects. Predominant liver biomarkers in common between WBI and WLI were amino acids, sugars, TCA metabolites (fumarate), fatty acids (lineolate, n-hexadecanoic acid) and DNA damage markers (uridine). Conclusions We identified a set of metabolomic markers that may prove useful as plasma biomarkers of RILD and WBI. Pathway analysis also suggested that the unique metabolic changes observed after liver irradiation was an integrative response of the intestine, liver and kidney. PMID:26046990

  6. Infrared Signature Masking by Air Plasma Radiation

    NASA Technical Reports Server (NTRS)

    Kruger, Charles H.; Laux, C. O.

    2001-01-01

    This report summarizes the results obtained during a research program on the infrared radiation of air plasmas conducted in the High Temperature Gasdynamics Laboratory at Stanford University under the direction of Professor Charles H. Kruger, with Dr. Christophe O. Laux as Associate Investigator. The goal of this research was to investigate the masking of infrared signatures by the air plasma formed behind the bow shock of high velocity missiles. To this end, spectral measurements and modeling were made of the radiation emitted between 2.4 and 5.5 micrometers by an atmospheric pressure air plasma in chemical and thermal equilibrium at a temperature of approximately 3000 K. The objective was to examine the spectral emission of air species including nitric oxide, atomic oxygen and nitrogen lines, molecular and atomic continua, as well as secondary species such as water vapor or carbon dioxide. The cold air stream injected in the plasma torch contained approximately 330 parts per million of CO2, which is the natural CO2 concentration in atmospheric air at room temperatures, and a small amount of water vapor with an estimated mole fraction of 3.8x10(exp -4).

  7. Defining functional signatures of dysbiosis in periodontitis progression.

    PubMed

    Wang, Gary P

    2015-01-01

    Periodontitis is a common inflammatory disease that leads to tooth loss and has been linked to cardiovascular disease and diabetes mellitus. The periodontal microbiome is highly diverse, and metatranscriptomic studies have indicated that the genes that are expressed by the microbiota are more relevant than the microbial composition in the pathogenesis of periodontitis. A recent study of early metabolic activities in the dysbiotic microbiome reveals a functional signature that distinguishes periodontal sites that will become inflamed, supporting the idea that microbial communities as a whole drive disease progression. PMID:25926890

  8. Infrared Signature Masking by Air Plasma Radiation

    NASA Technical Reports Server (NTRS)

    Kruger, C. H.; Laux, C. O.

    1998-01-01

    Detailed measurements and modeling of the spectral emission of an atmospheric pressure air plasma at temperatures up to -3400 K have been made. The cold gas injected in the plasma torch contained an estimated mole fraction of water vapor of approximately 4.5 x 10(exp -3) and an estimated carbon dioxide mole fraction of approximately 3.3 x 10(exp -4). Under these conditions, the minimum level of air plasma emission is found to be between 3.9 and 4.15 microns. Outside this narrow region, significant spectral emission is detected that can be attributed to the fundamental and overtone bands of NO and OH, and to the v(sub 3) and the (v(sub 1)+v(sub 3)) bands Of CO2. Special attention was paid to the effects of ambient air absorption in the optical path between the plasma and the detector. Excellent quantitative agreement is obtained between the measured and simulated spectra, which are both on absolute intensity scales, thus lending confidence in the radiation models incorporated into NEQAIR2-IR over the course of this research program.

  9. The signature of auroral kilometric radiation on Isis 1 ionograms

    NASA Technical Reports Server (NTRS)

    Calvert, W.

    1981-01-01

    Auroral kilometric radiation (AKR) appears on the Isis 1 topside sounder ionograms as intense noise bands between the electron cyclotron frequency and 700 kHz. A variable gap occurs between the cyclotron frequency and the lowest AKR frequency. As Isis 1 traverses the source region, the gap narrows, and the AKR signals at higher frequencies weaken. This signature suggests that the AKR waves are generated directly in the extraordinary mode at frequencies just above the local cutoff frequency and that the radiation is initially perpendicular to the magnetic field.

  10. Quantum Signature of Analog Hawking Radiation in Momentum Space.

    PubMed

    Boiron, D; Fabbri, A; Larré, P-É; Pavloff, N; Westbrook, C I; Ziń, P

    2015-07-10

    We consider a sonic analog of a black hole realized in the one-dimensional flow of a Bose-Einstein condensate. Our theoretical analysis demonstrates that one- and two-body momentum distributions accessible by present-day experimental techniques provide clear direct evidence (i) of the occurrence of a sonic horizon, (ii) of the associated acoustic Hawking radiation, and (iii) of the quantum nature of the Hawking process. The signature of the quantum behavior persists even at temperatures larger than the chemical potential. PMID:26207475

  11. Radiation signatures in childhood thyroid cancers after the Chernobyl accident: possible roles of radiation in carcinogenesis.

    PubMed

    Suzuki, Keiji; Mitsutake, Norisato; Saenko, Vladimir; Yamashita, Shunichi

    2015-02-01

    After the Tokyo Electric Power Company Fukushima Daiichi nuclear power plant accident, cancer risk from low-dose radiation exposure has been deeply concerning. The linear no-threshold model is applied for the purpose of radiation protection, but it is a model based on the concept that ionizing radiation induces stochastic oncogenic alterations in the target cells. As the elucidation of the mechanism of radiation-induced carcinogenesis is indispensable to justify the concept, studies aimed at the determination of molecular changes associated with thyroid cancers among children who suffered effects from the Chernobyl nuclear accident will be overviewed. We intend to discuss whether any radiation signatures are associated with radiation-induced childhood thyroid cancers. PMID:25483826

  12. Radiation signatures in childhood thyroid cancers after the Chernobyl accident: Possible roles of radiation in carcinogenesis

    PubMed Central

    Suzuki, Keiji; Mitsutake, Norisato; Saenko, Vladimir; Yamashita, Shunichi

    2015-01-01

    After the Tokyo Electric Power Company Fukushima Daiichi nuclear power plant accident, cancer risk from low-dose radiation exposure has been deeply concerning. The linear no-threshold model is applied for the purpose of radiation protection, but it is a model based on the concept that ionizing radiation induces stochastic oncogenic alterations in the target cells. As the elucidation of the mechanism of radiation-induced carcinogenesis is indispensable to justify the concept, studies aimed at the determination of molecular changes associated with thyroid cancers among children who suffered effects from the Chernobyl nuclear accident will be overviewed. We intend to discuss whether any radiation signatures are associated with radiation-induced childhood thyroid cancers. PMID:25483826

  13. Radiative signature of magnetic fields in internal shocks

    NASA Astrophysics Data System (ADS)

    Mimica, P.; Aloy, M. A.

    2012-04-01

    Common models of blazars and gamma-ray bursts assume that the plasma underlying the observed phenomenology is magnetized to some extent. Within this context, radiative signatures of dissipation of kinetic and conversion of magnetic energy in internal shocks of relativistic magnetized outflows are studied. We model internal shocks as being caused by collisions of homogeneous plasma shells. We compute the flow state after the shell interaction by solving Riemann problems at the contact surface between the colliding shells, and then compute the emission from the resulting shocks. Under the assumption of a constant flow luminosity, we find that there is a clear difference between the models where both shells are weakly magnetized (σ≲ 10-2) and those where, at least, one shell has σ≳ 10-2. We obtain that the radiative efficiency is largest for models in which, regardless of the ordering, one shell is weakly and the other strongly magnetized. Substantial differences between weakly and strongly magnetized shell collisions are observed in the inverse-Compton part of the spectrum, as well as in the optical, X-ray and 1-GeV light curves. We propose a way to distinguish observationally between weakly magnetized and strongly magnetized internal shocks by comparing the maximum frequency of the inverse-Compton part and synchrotron part of the spectrum to the ratio of the inverse-Compton to synchrotron fluence. Finally, our results suggest that low-frequency peaked blazars (LBL) may correspond to barely magnetized flows, while high-frequency peaked blazars (HBL) could correspond to moderately magnetized ones. Indeed, by comparing with actual blazar observations, we conclude that the magnetization of typical blazars is σ≲ 0.01 for the internal shock model to be valid in these sources.

  14. Progress in interpreting CO2 lidar signatures to obtain cirrus microphysical and optical properties

    NASA Technical Reports Server (NTRS)

    Eberhard, Wynn L.

    1993-01-01

    One cloud/radiation issue at FIRE 2 that has been addressed by the CO2 lidar team is the zenith-enhanced backscatter (ZEB) signature from oriented crystals. A second topic is narrow-beam optical depth measurements using CO2 lidar. This paper describes the theoretical models we have developed for these phenomena and the data-processing algorithms derived from them.

  15. Subtype-specific micro-RNA expression signatures in breast cancer progression.

    PubMed

    Haakensen, Vilde D; Nygaard, Vegard; Greger, Liliana; Aure, Miriam R; Fromm, Bastian; Bukholm, Ida R K; Lüders, Torben; Chin, Suet-Feung; Git, Anna; Caldas, Carlos; Kristensen, Vessela N; Brazma, Alvis; Børresen-Dale, Anne-Lise; Hovig, Eivind; Helland, Åslaug

    2016-09-01

    Robust markers of invasiveness may help reduce the overtreatment of in situ carcinomas. Breast cancer is a heterogeneous disease and biological mechanisms for carcinogenesis vary between subtypes. Stratification by subtype is therefore necessary to identify relevant and robust signatures of invasive disease. We have identified microRNA (miRNA) alterations during breast cancer progression in two separate datasets and used stratification and external validation to strengthen the findings. We analyzed two separate datasets (METABRIC and AHUS) consisting of a total of 186 normal breast tissue samples, 18 ductal carcinoma in situ (DCIS) and 1,338 invasive breast carcinomas. Validation in a separate dataset and stratification by molecular subtypes based on immunohistochemistry, PAM50 and integrated cluster classifications were performed. We propose subtype-specific miRNA signatures of invasive carcinoma and a validated signature of DCIS. miRNAs included in the invasive signatures include downregulation of miR-139-5p in aggressive subtypes and upregulation of miR-29c-5p expression in the luminal subtypes. No miRNAs were differentially expressed in the transition from DCIS to invasive carcinomas on the whole, indicating the need for subtype stratification. A total of 27 miRNAs were included in our proposed DCIS signature. Significant alterations of expression included upregulation of miR-21-5p and the miR-200 family and downregulation of let-7 family members in DCIS samples. The signatures proposed here can form the basis for studies exploring DCIS samples with increased invasive potential and serum biomarkers for in situ and invasive breast cancer. PMID:27082076

  16. Commercial Sensory Survey Radiation Testing Progress Report

    NASA Technical Reports Server (NTRS)

    Becker, Heidi N.; Dolphic, Michael D.; Thorbourn, Dennis O.; Alexander, James W.; Salomon, Phil M.

    2008-01-01

    The NASA Electronic Parts and Packaging (NEPP) Program Sensor Technology Commercial Sensor Survey task is geared toward benefiting future NASA space missions with low-cost, short-duty-cycle, visible imaging needs. Such applications could include imaging for educational outreach purposes or short surveys of spacecraft, planetary, or lunar surfaces. Under the task, inexpensive commercial grade CMOS sensors were surveyed in fiscal year 2007 (FY07) and three sensors were selected for total ionizing dose (TID) and displacement damage dose (DDD) tolerance testing. The selected sensors had to meet selection criteria chosen to support small, low-mass cameras that produce good resolution color images. These criteria are discussed in detail in [1]. This document discusses the progress of radiation testing on the Micron and OmniVision sensors selected in FY07 for radiation tolerance testing.

  17. Signatures of quantum radiation reaction in laser-electron-beam collisions

    SciTech Connect

    Wang, H. Y.; Yan, X. Q.; Zepf, M.

    2015-09-15

    Electron dynamics in the collision of an electron beam with a high-intensity focused ultrashort laser pulse are investigated using three-dimensional QED particle-in-cell (PIC) simulations, and the results are compared with those calculated by classical Landau and Lifshitz PIC simulations. Significant differences are observed from the angular dependence of the electron energy distribution patterns for the two different approaches, because photon emission is no longer well approximated by a continuous process in the quantum radiation-dominated regime. The stochastic nature of photon emission results in strong signatures of quantum radiation-reaction effects under certain conditions. We show that the laser spot size and duration greatly influence these signatures due to the competition of QED effects and the ponderomotive force, which is well described in the classical approximation. The clearest signatures of quantum radiation reaction are found in the limit of large laser spots and few cycle pulse durations.

  18. Positron line radiation from halo WIMP annihilations as a dark matter signature

    NASA Technical Reports Server (NTRS)

    Turner, Michael S.; Wilczek, Frank

    1989-01-01

    We suggest a new signature for dark matter annihilation in the halo: high energy positron line radiation. Because the cosmic ray positron spectrum falls rapidly with energy, e+'s from halo WIMP annihilations can be a significant, clean signal for very massive WIMP's (approx. greater than 30 GeV). In the case that the e+e- annihilation channel has an appreciable branch, the e+ signal should be above background in a future detector, such as have been proposed for ASTROMAG, and of potential importance as a dark matter signature. A significant e+e- branching ratio can occur for neutralinos or Dirac neutrinos. High-energy, continuum positron radiation may also be an important signature for massive neutralino annihilations, especially near or above the threshold of the W+W- and ZoZo annihilation channels.

  19. Solving Inverse Detection Problems Using Passive Radiation Signatures

    SciTech Connect

    Favorite, Jeffrey A.; Armstrong, Jerawan C.; Vaquer, Pablo A.

    2012-08-15

    The ability to reconstruct an unknown radioactive object based on its passive gamma-ray and neutron signatures is very important in homeland security applications. Often in the analysis of unknown radioactive objects, for simplicity or speed or because there is no other information, they are modeled as spherically symmetric regardless of their actual geometry. In these presentation we discuss the accuracy and implications of this approximation for decay gamma rays and for neutron-induced gamma rays. We discuss an extension of spherical raytracing (for uncollided fluxes) that allows it to be used when the exterior shielding is flat or cylindrical. We revisit some early results in boundary perturbation theory, showing that the Roussopolos estimate is the correct one to use when the quantity of interest is the flux or leakage on the boundary. We apply boundary perturbation theory to problems in which spherically symmetric systems are perturbed in asymmetric nonspherical ways. We apply mesh adaptive direct search (MADS) algorithms to object reconstructions. We present a benchmark test set that may be used to quantitatively evaluate inverse detection methods.

  20. Radiation signature on exposed cells: Relevance in dose estimation.

    PubMed

    Perumal, Venkatachalam; Gnana Sekaran, Tamizh Selvan; Raavi, Venkateswarlu; Basheerudeen, Safa Abdul Syed; Kanagaraj, Karthik; Chowdhury, Amith Roy; Paul, Solomon Fd

    2015-09-28

    The radiation is considered as a double edged sword, as its beneficial and detrimental effects have been demonstrated. The potential benefits are being exploited to its maximum by adopting safe handling of radionuclide stipulated by the regulatory agencies. While the occupational workers are monitored by personnel monitoring devices, for general publics, it is not a regular practice. However, it can be achieved by using biomarkers with a potential for the radiation triage and medical management. An ideal biomarker to adopt in those situations should be rapid, specific, sensitive, reproducible, and able to categorize the nature of exposure and could provide a reliable dose estimation irrespective of the time of the exposures. Since cytogenetic markers shown to have many advantages relatively than other markers, the origins of various chromosomal abnormalities induced by ionizing radiations along with dose-response curves generated in the laboratory are presented. Current status of the gold standard dicentric chromosome assay, micronucleus assay, translocation measurement by fluorescence in-situ hybridization and an emerging protein marker the γ-H2AX assay are discussed with our laboratory data. With the wide choice of methods, an appropriate assay can be employed based on the net. PMID:26435777

  1. Radiation signature on exposed cells: Relevance in dose estimation

    PubMed Central

    Perumal, Venkatachalam; Gnana Sekaran, Tamizh Selvan; Raavi, Venkateswarlu; Basheerudeen, Safa Abdul Syed; Kanagaraj, Karthik; Chowdhury, Amith Roy; Paul, Solomon FD

    2015-01-01

    The radiation is considered as a double edged sword, as its beneficial and detrimental effects have been demonstrated. The potential benefits are being exploited to its maximum by adopting safe handling of radionuclide stipulated by the regulatory agencies. While the occupational workers are monitored by personnel monitoring devices, for general publics, it is not a regular practice. However, it can be achieved by using biomarkers with a potential for the radiation triage and medical management. An ideal biomarker to adopt in those situations should be rapid, specific, sensitive, reproducible, and able to categorize the nature of exposure and could provide a reliable dose estimation irrespective of the time of the exposures. Since cytogenetic markers shown to have many advantages relatively than other markers, the origins of various chromosomal abnormalities induced by ionizing radiations along with dose-response curves generated in the laboratory are presented. Current status of the gold standard dicentric chromosome assay, micronucleus assay, translocation measurement by fluorescence in-situ hybridization and an emerging protein marker the γ-H2AX assay are discussed with our laboratory data. With the wide choice of methods, an appropriate assay can be employed based on the net. PMID:26435777

  2. Age gene expression and coexpression progressive signatures in peripheral blood leukocytes.

    PubMed

    Irizar, Haritz; Goñi, Joaquín; Alzualde, Ainhoa; Castillo-Triviño, Tamara; Olascoaga, Javier; Lopez de Munain, Adolfo; Otaegui, David

    2015-12-01

    Both cellular senescence and organismic aging are known to be dynamic processes that start early in life and progress constantly during the whole life of the individual. In this work, with the objective of identifying signatures of age-related progressive change at the transcriptomic level, we have performed a whole-genome gene expression analysis of peripheral blood leukocytes in a group of healthy individuals with ages ranging from 14 to 93 years. A set of genes with progressively changing gene expression (either increase or decrease with age) has been identified and contextualized in a coexpression network. A modularity analysis has been performed on this network and biological-term and pathway enrichment analyses have been used for biological interpretation of each module. In summary, the results of the present work reveal the existence of a transcriptomic component that shows progressive expression changes associated to age in peripheral blood leukocytes, highlighting both the dynamic nature of the process and the need to complement young vs. elder studies with longitudinal studies that include middle aged individuals. From the transcriptional point of view, immunosenescence seems to be occurring from a relatively early age, at least from the late 20s/early 30s, and the 49-56 year old age-range appears to be critical. In general, the genes that, according to our results, show progressive expression changes with aging are involved in pathogenic/cellular processes that have classically been linked to aging in humans: cancer, immune processes and cellular growth vs. maintenance. PMID:26362218

  3. Meta-Analysis of Gene Expression Signatures Defining the Epithelial to Mesenchymal Transition during Cancer Progression

    PubMed Central

    Gröger, Christian J.; Grubinger, Markus; Waldhör, Thomas; Vierlinger, Klemens; Mikulits, Wolfgang

    2012-01-01

    The epithelial to mesenchymal transition (EMT) represents a crucial event during cancer progression and dissemination. EMT is the conversion of carcinoma cells from an epithelial to a mesenchymal phenotype that associates with a higher cell motility as well as enhanced chemoresistance and cancer stemness. Notably, EMT has been increasingly recognized as an early event of metastasis. Numerous gene expression studies (GES) have been conducted to obtain transcriptome signatures and marker genes to understand the regulatory mechanisms underlying EMT. Yet, no meta-analysis considering the multitude of GES of EMT has been performed to comprehensively elaborate the core genes in this process. Here we report the meta-analysis of 18 independent and published GES of EMT which focused on different cell types and treatment modalities. Computational analysis revealed clustering of GES according to the type of treatment rather than to cell type. GES of EMT induced via transforming growth factor-β and tumor necrosis factor-α treatment yielded uniformly defined clusters while GES of models with alternative EMT induction clustered in a more complex fashion. In addition, we identified those up- and downregulated genes which were shared between the multitude of GES. This core gene list includes well known EMT markers as well as novel genes so far not described in this process. Furthermore, several genes of the EMT-core gene list significantly correlated with impaired pathological complete response in breast cancer patients. In conclusion, this meta-analysis provides a comprehensive survey of available EMT expression signatures and shows fundamental insights into the mechanisms that are governing carcinoma progression. PMID:23251436

  4. Numerical study on the influence of aluminum on infrared radiation signature of exhaust plume

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Ye, Qing-qing; Li, Shi-peng; Wang, Ning-fei

    2013-09-01

    The infrared radiation signature of exhaust plume from solid propellant rockets has been widely mentioned for its important realistic meaning. The content of aluminum powder in the propellants is a key factor that affects the infrared radiation signature of the plume. The related studies are mostly on the conical nozzles. In this paper, the influence of aluminum on the flow field of plume, temperature distribution, and the infrared radiation characteristics were numerically studied with an object of 3D quadrate nozzle. Firstly, the gas phase flow field and gas-solid multi phase flow filed of the exhaust plume were calculated using CFD method. The result indicates that the Al203 particles have significant effect on the flow field of plume. Secondly, the radiation transfer equation was solved by using a discrete coordinate method. The spectral radiation intensity from 1000-2400 cm-1 was obtained. To study the infrared radiation characteristics of exhaust plume, an exceptional quadrate nozzle was employed and much attention was paid to the influences of Al203 particles in solid propellants. The results could dedicate the design of the divert control motor in such hypervelocity interceptors or missiles, or be of certain meaning to the improvement of ingredients of solid propellants.

  5. Polarimetric signatures of a coniferous forest canopy based on vector radiative transfer theory

    NASA Technical Reports Server (NTRS)

    Karam, M. A.; Fung, A. K.; Amar, F.; Mougin, E.; Lopes, A.; Beaudoin, A.

    1992-01-01

    Complete polarization signatures of a coniferous forest canopy are studied by the iterative solution of the vector radiative transfer equations up to the second order. The forest canopy constituents (leaves, branches, stems, and trunk) are embedded in a multi-layered medium over a rough interface. The branches, stems and trunk scatterers are modeled as finite randomly oriented cylinders. The leaves are modeled as randomly oriented needles. For a plane wave exciting the canopy, the average Mueller matrix is formulated in terms of the iterative solution of the radiative transfer solution and used to determine the linearly polarized backscattering coefficients, the co-polarized and cross-polarized power returns, and the phase difference statistics. Numerical results are presented to investigate the effect of transmitting and receiving antenna configurations on the polarimetric signature of a pine forest. Comparison is made with measurements.

  6. A Statistical Model for Generating a Population of Unclassified Objects and Radiation Signatures Spanning Nuclear Threats

    SciTech Connect

    Nelson, K; Sokkappa, P

    2008-10-29

    This report describes an approach for generating a simulated population of plausible nuclear threat radiation signatures spanning a range of variability that could be encountered by radiation detection systems. In this approach, we develop a statistical model for generating random instances of smuggled nuclear material. The model is based on physics principles and bounding cases rather than on intelligence information or actual threat device designs. For this initial stage of work, we focus on random models using fissile material and do not address scenarios using non-fissile materials. The model has several uses. It may be used as a component in a radiation detection system performance simulation to generate threat samples for injection studies. It may also be used to generate a threat population to be used for training classification algorithms. In addition, we intend to use this model to generate an unclassified 'benchmark' threat population that can be openly shared with other organizations, including vendors, for use in radiation detection systems performance studies and algorithm development and evaluation activities. We assume that a quantity of fissile material is being smuggled into the country for final assembly and that shielding may have been placed around the fissile material. In terms of radiation signature, a nuclear weapon is basically a quantity of fissile material surrounded by various layers of shielding. Thus, our model of smuggled material is expected to span the space of potential nuclear weapon signatures as well. For computational efficiency, we use a generic 1-dimensional spherical model consisting of a fissile material core surrounded by various layers of shielding. The shielding layers and their configuration are defined such that the model can represent the potential range of attenuation and scattering that might occur. The materials in each layer and the associated parameters are selected from probability distributions that span the

  7. Wave like signatures in aerosol optical depth and associated radiative impacts over the central Himalayan region

    NASA Astrophysics Data System (ADS)

    Shukla, K. K.; Phanikumar, D. V.; Kumar, K. Niranjan; Reddy, Kishore; Kotamarthi, V. R.; Newsom, Rob K.; Ouarda, Taha B. M. J.

    2015-10-01

    Doppler Lidar and Multi-Filter Rotating Shadowband Radiometer (MFRSR) observations are utilized to show wave like signatures in aerosol optical depth (AOD) during daytime boundary layer evolution over the Himalayan region. Fourier analysis depicted 60-80 min periods dominant during afternoon hours, implying that observed modulations could be plausible reason for the AOD forenoon-afternoon asymmetry which was previously reported. Inclusion of wave amplitude in diurnal variation of aerosol radiative forcing estimates showed ~40% additional warming in the atmosphere relative to mean AOD. The present observations emphasize the importance of wave induced variations in AOD and radiation budget over the site.

  8. Progress in radiation processing of polymers

    NASA Astrophysics Data System (ADS)

    Chmielewski, Andrzej G.; Haji-Saeid, Mohammad; Ahmed, Shamshad

    2005-07-01

    Modification in polymeric structure of plastic material can be brought either by conventional chemical means or by exposure to ionization radiation from ether radioactive sources or highly accelerated electrons. The prominent drawbacks of chemical cross-linking typically involve the generation of noxious fumes and by products of peroxide degradation. Both the irradiation sources have their merits and limitations. Increased utilization of electron beams for modification and enhancement of polymer materials has been in particular witnessed over the past 40 years. The paper highlights several recent cases of EB utilization to improve key properties of selected plastic products. In paper is provided a survey of radiation processing methods of industrial interest, encompassing technologies which are already commercially well established, through developments in the active R&D stage which show pronounced promise for future commercial use. Radiation cross-linking technologies discussed include: application in cable and wire, application in rubber tyres, radiation vulcanization of rubber latex, development of radiation crosslinked SiC fiber, polymer recycling, development of gamma compatible pp, hydrogels etc. Over the years, remarkable advancement has been achieved in radiation processing of natural polymers. Role of radiation in improving the processing of temperature of PCL for use as biodegradable polymer, in accelerated breakdown of cellulose into viscose and enhancement in yields of chitin/chitosan from sea-food waste, is described.

  9. Radiation transport. Progress report, October 1, 1982-March 31, 1983

    SciTech Connect

    O'Dell, R.D.

    1984-05-01

    Research and development progress in radiation transport by the Los Alamos National Laboratory's Group X-6 for the first half of FY 83 is reported. Included are tasks in the areas of Fission Reactor Neutronics, Deterministic Transport Methods, and Monte Carlo Radiation Transport.

  10. Radiation transport. Progress report, April 1-December 31, 1983

    SciTech Connect

    O'Dell, R.D.

    1984-10-01

    Research and development progress in radiation transport by the Los Alamos National Laboratory's Group X-6 for the last nine months of CY 83 is reported. Included are unclassified tasks in the areas of Fission Reactor Neutronics, Deterministic Transport Methods, Monte Carlo Radiation Transport, and Cross Sections and Physics.

  11. RADIATIVE DAMPING AND EMISSION SIGNATURES OF STRONG SUPERLUMINAL WAVES IN PULSAR WINDS

    SciTech Connect

    Mochol, Iwona; Kirk, John G. E-mail: john.kirk@mpi-hd.mpg.de

    2013-10-10

    We analyze the damping of strong, superluminal electromagnetic waves by radiation reaction and Compton drag in the context of pulsar winds. The associated radiation signature is found by estimating the efficiency and the characteristic radiation frequencies. Applying these estimates to the gamma-ray binary containing PSR B1259–63, we show that the GeV flare observed by the Fermi Large Area Telescope can be understood as inverse-Compton emission by particles scattering photons from the companion star, if the pulsar wind termination shock acquires a precursor of superluminal waves roughly 30 days after periastron. This requirement constrains the mass-loading factor of the wind μ=L/ N-dot mc{sup 2}, where L is the luminosity and N-dot is the rate of loss of electrons and positrons, to be roughly 6 × 10{sup 4}.

  12. Signatures of semi-direct radiative forcing by absorbing aerosols in satellite observations and models

    NASA Astrophysics Data System (ADS)

    Wilcox, E. M.; Hosseinpour, F.; Colarco, P. R.

    2014-12-01

    Semi-direct radiative forcing of climate occurs when interactions between aerosols and radiative fluxes in the atmosphere yield a dynamical response in clouds. Semi-direct forcing is typically thought to be a positive radiative forcing whereby soot and biomass burning aerosols absorb sunlight and burn-off clouds. However, a negative semi-direct forcing is suspected in at least two regimes, the summertime Southeast Atlantic Ocean and the wintertime North Indian Ocean, where the heating profile by aerosol absorption by solar radiation is elevated above the elevation of the low clouds. Here we use a combination of satellite data and a model simulation to further characterize the signature of semi-direct radiative forcing in these two locations and elsewhere on the globe. We apply CERES albedos, Calipso profiles of aerosol extinction and cloud-top altitude, and a simulation with the Goddard Earth Observing System Model version 5 (GEOS-5) Earth system model with meteorology constrained by MERRA and an assimilation of MODIS AOT (MERRAero). to quantify the vertical heating profile by aerosols under clear and cloudy skies. We seek to determine: (1) where aerosol heating by soot and biomass burning aerosol is occurring; (2) where vertically in the column the heating is occurring relative to the observed level of low cloud development; and (3) whether the variations of albedo with aerosol forcing suggest a positive, negative, or inconclusive semi-direct radiative forcing.

  13. Second dip as a signature of ultrahigh energy proton interactions with cosmic microwave background radiation.

    PubMed

    Berezinsky, V; Gazizov, A; Kachelrieb, M

    2006-12-01

    We discuss as a new signature for the interaction of extragalactic ultrahigh energy protons with cosmic microwave background radiation a spectral feature located at E= 6.3 x 10(19) eV in the form of a narrow and shallow dip. It is produced by the interference of e+e(-)-pair and pion production. We show that this dip and, in particular, its position are almost model-independent. Its observation by future ultrahigh energy cosmic ray detectors may give the conclusive confirmation that an observed steepening of the spectrum is caused by the Greisen-Zatsepin-Kuzmin effect. PMID:17280191

  14. Multielectron signatures in the polarization of high-order harmonic radiation

    SciTech Connect

    Zhao Zengxiu; Yuan Jianmin; Brabec, Thomas

    2007-09-15

    The polarization of high-order harmonic radiation emitted from N{sub 2} molecules interacting with a linearly polarized laser pulse is investigated theoretically. We find that the exchange effect between the recombining electron and the bound core electrons imprints a clear signature onto the high-order harmonic polarization and its dependence on the alignment angle between the molecular axis and driving laser electric field. Our analysis reveals an observable for the experimental investigation of many-electron dynamics in intense laser fields.

  15. Signature mutations from B. subtilis spores exposed to radiations and simulated space environments

    NASA Astrophysics Data System (ADS)

    Munakata, , Nobuo; Natsume, Toshiyuki; Konishi, Teruaki; Hieda, Kotaro; Panitz, Corinna; Horneck, Gerda

    Rifampicin-resistant mutants were collected from the spores of three B. subtilis strains, HA101 (HA, repair proficient), TKJ6312 (US, UV-repair defective) and TKJ6412 (RF, recombination deficient) grown after exposure to various radiations and simulated space environments. All of 563 mutations analyzed carried sequence changes in the N-terminal region of the rpoB gene cod-ing for the subunit β of RNA polymerase II and belonged to 56 alleles. (1) Most of spontaneous mutants from the three strains belonged to 13 single-base substitution (SBS) alleles, exceptions (<2%) being one 3 bp insertion and one tandem double substitution (TDS). (2) About 6 % and 16 % of the mutations from the HA and RF spores, respectively, exposed to ionizing radiations were complex mutations including multiple-base substitutions, insertions and deletions. Several TDS and non-tandem double substitutions (NTDS), and 3, 6, 9 and one 30 bp deletions seem to provide signatures of the exposure to ionizing radiations. (3) Except one TDS from US and one NTDS from HA spores, UV or solar exposure seemed not to leave unique footprints. (4) In space simulation experiments, the only conditions involving high vacuum consistently increased the mutation frequency, and exhibited high occurrences (>50%) of TDS. In HA spores, the al-lele r201 (CA to TT at 1460) was the most frequent, while in US spores, another allele r210 (TC to AA at 1404) was the most frequent. In conclusion, some of the conditions encountered in space environments, such as space vacuum and ionizing radiations, could produce unique mutational signatures in the rpoB gene of B. subtilis spores.

  16. Progress in radiation immune thermionic integrated circuits

    SciTech Connect

    Lynn, D.K.; McCormick, J.B.

    1985-08-01

    This report describes the results of a program directed at evaluating the thermionic integrated circuit (TIC) technology for applicability to military systems. Previous programs under the sponsorship of the Department of Energy, Office of Basic Energy Sciences, have developed an initial TIC technology base and demonstrated operation in high-temperature and high-radiation environments. The program described in this report has two parts: (1) a technical portion in which experiments and analyses were conducted to refine perceptions of near-term as well as ultimate performance levels of the TIC technology and (2) an applications portion in which the technical conclusions were to be evaluated against potential military applications. This report draws several conclusions that strongly suggest that (1) useful radiation-hard/high-temperature operable integrated circuits can be developed using the TIC technology; (2) because of their ability to survive and operate in hostile environments, a variety of potential military applications have been projected for this technology; and (3) based on the above two conclusions, an aggressive TIC development program should be initiated to provide the designers of future systems with integrated circuits and devices with the unique features of the TICs.

  17. Nucleoplasmic bridges and tailed nuclei are signatures of radiation exposure in Oreochromis mossambicus using erythrocyte micronucleus cytome assay (EMNCA).

    PubMed

    Anbumani, S; Mohankumar, Mary N

    2015-12-01

    Gamma radiation-induced genetic perturbations in aquatic vertebrates is largely unknown at low-dose rate, especially in the wake of a nuclear disaster and/or other environmental outbreaks. Freshwater fish, Oreochromis mossambicus subjected to low-dose rate (2 mGy/min) at 2.5-, 5-, and 10-Gy doses, were analyzed for "exposure signatures" in blood samples drawn on days 3, 6, 12, 18, and 30, respectively. Significant dose-dependent increments in micronuclei frequency and other anomalies such as nucleoplasmic bridges and tailed nuclei were observed and exhibit a strong positive correlation, suggesting that they could be used as prospective signatures of radiation exposure. Similarly increased incidence of apoptosis and DNA repair machinery circuits at high and low doses were noted. This work highlighted "cytogenetic signatures" in fish and the sensitivity of these endpoints toward low-dose rate of radiation exposure. PMID:26263884

  18. Microwave Polarized Signatures Generated within Cloud Systems: SSM/I Observations Interpreted with Radiative Transfer Simulations

    NASA Technical Reports Server (NTRS)

    Prigent, Catherine; Pardo, Juan R.; Mishchenko, Michael I.; Rossow, Willaim B.; Hansen, James E. (Technical Monitor)

    2001-01-01

    Special Sensor Microwave /Imager (SSM/I) observations in cloud systems are studied over the tropics. Over optically thick cloud systems, presence of polarized signatures at 37 and 85 GHz is evidenced and analyzed with the help of cloud top temperature and optical thickness extracted from visible and IR satellite observations. Scattering signatures at 85 GHz (TbV(85) less than or = 250 K) are associated with polarization differences greater than or = 6 K, approx. 50%, of the time over ocean and approx. 40% over land. In addition. over thick clouds the polarization difference at 37 GHz is rarely negligible. The polarization differences at 37 and 85 GHz do not stem from the surface but are generated in regions of relatively homogeneous clouds having high liquid water content. To interpret the observations, a radiative transfer model that includes the scattering by non-spherical particles is developed. based on the T-matrix approach and using the doubling and adding method. In addition to handling randomly and perfectly oriented particles, this model can also simulate the effect of partial orientation of the hydrometeors. Microwave brightness temperatures are simulated at SSM/I frequencies and are compared with the observations. Polarization differences of approx. 2 K can be simulated at 37 GHz over a rain layer, even using spherical drops. The polarization difference is larger for oriented non-spherical particles. The 85 GHz simulations are very sensitive to the ice phase of the cloud. Simulations with spherical particles or with randomly oriented non-spherical ice particles cannot replicate the observed polarization differences. However, with partially oriented non-spherical particles, the observed polarized signatures at 85 GHz are explained, and the sensitivity of the scattering characteristics to the particle size, asphericity, and orientation is analyzed. Implications on rain and ice retrievals are discussed.

  19. Radiative signatures of Z-pinch plasmas at UNR: from X-pinches to wire arrays

    NASA Astrophysics Data System (ADS)

    Safronova, A. S.; Kantsyrev, V. L.; Esaulov, A. A.; Safronova, U. I.; Shlyaptseva, V. V.; Shrestha, I.; Osborne, G. C.; Weller, M. E.; Stafford, A.; Lorance, M.; Chuvatin, A. S.

    2014-08-01

    University-scale Z-pinch generators are able to produce High Energy Density (HED) plasmas in a broad range of plasma parameters under well-controlled and monitored experimental conditions suitable for radiation studies. The implosion of X-pinch and wire array loads at a 1 MA generator yields short (1-20 nsec) x-ray bursts from one or several bright plasma spots near the wire cross point (for X-pinches) or along and near Z-pinch axis (for wire arrays). Such X- and Z-pinch HED plasma with scales from a few µm to several mm in size emits radiation in a broad range of energies from 10 eV to 0.5 MeV and is subject of our studies during the last ten years. In particular, the substantial number of experiments with very different wire loads was performed on the 1 MA Zebra generator and analyzed: X-pinch, cylindrical, nested, and various types of the novel load, Planar Wire Arrays (PWA). Also, the experiments at an enhanced current of 1.5-1.7 MA on Zebra using Load Current Multiplier (LCM) were performed. This paper highlights radiative signatures of X-pinches and Single and Double PWAs which are illustrated using the new results with combined wire loads from two different materials.

  20. Implications of genotypic differences in the generation of a urinary metabolomics radiation signature.

    PubMed

    Laiakis, Evagelia C; Pannkuk, Evan L; Diaz-Rubio, Maria Elena; Wang, Yi-Wen; Mak, Tytus D; Simbulan-Rosenthal, Cynthia M; Brenner, David J; Fornace, Albert J

    2016-06-01

    The increased threat of radiological terrorism and accidental nuclear exposures, together with increased usage of radiation-based medical procedures, has made necessary the development of minimally invasive methods for rapid identification of exposed individuals. Genetically predisposed radiosensitive individuals comprise a significant number of the population and require specialized attention and treatments after such events. Metabolomics, the assessment of the collective small molecule content in a given biofluid or tissue, has proven effective in the rapid identification of radiation biomarkers and metabolic perturbations. To investigate how the genotypic background may alter the ionizing radiation (IR) signature, we analyzed urine from Parp1(-/-) mice, as a model radiosensitive genotype, exposed to IR by utilizing the analytical power of liquid chromatography coupled with mass spectrometry (LC-MS), as urine has been thoroughly investigated in wild type (WT) mice in previous studies from our laboratory. Samples were collected at days one and three after irradiation, time points that are important for the early and efficient triage of exposed individuals. Time-dependent perturbations in metabolites were observed in the tricarboxylic acid pathway (TCA). Other differentially excreted metabolites included amino acids and metabolites associated with dysregulation of energy metabolism pathways. Time-dependent apoptotic pathway activation between WT and mutant mice following IR exposure may explain the altered excretion patterns, although the origin of the metabolites remains to be determined. This first metabolomics study in urine from radiation exposed genetic mutant animal models provides evidence that this technology can be used to dissect the effects of genotoxic agents on metabolism by assessing easily accessible biofluids and identify biomarkers of radiation exposure. Applications of metabolomics could be incorporated in the future to further elucidate the

  1. Development of a Metabolomic Radiation Signature in Urine from Patients Undergoing Total Body Irradiation

    PubMed Central

    Laiakis, Evagelia C.; Mak, Tytus D.; Anizan, Sebastien; Amundson, Sally A.; Barker, Christopher A.; Wolden, Suzanne L.; Brenner, David J.; Fornace, Albert J.

    2014-01-01

    The emergence of the threat of radiological terrorism and other radiological incidents has led to the need for development of fast, accurate and noninvasive methods for detection of radiation exposure. The purpose of this study was to extend radiation metabolomic biomarker discovery to humans, as previous studies have focused on mice. Urine was collected from patients undergoing total body irradiation at Memorial Sloan-Kettering Cancer Center prior to hematopoietic stem cell transplantation at 4–6 h postirradiation (a single dose of 1.25 Gy) and 24 h (three fractions of 1.25 Gy each). Global metabolomic profiling was obtained through analysis with ultra performance liquid chromatography coupled to time-of-flight mass spectrometry (TOFMS). Prior to further analyses, each sample was normalized to its respective creatinine level. Statistical analysis was conducted by the nonparametric Kolmogorov-Smirnov test and the Fisher’s exact test and markers were validated against pure standards. Seven markers showed distinct differences between pre- and post-exposure samples. Of those, trimethyl-l-lysine and the carnitine conjugates acetylcarnitine, decanoylcarnitine and octanoylcarnitine play an important role in the transportation of fatty acids across mitochondria for subsequent fatty acid β-oxidation. The remaining metabolites, hypoxanthine, xanthine and uric acid are the final products of the purine catabolism pathway, and high levels of excretion have been associated with increased oxidative stress and radiation induced DNA damage. Further analysis revealed sex differences in the patterns of excretion of the markers, demonstrating that generation of a sex-specific metabolomic signature will be informative and can provide a quick and reliable assessment of individuals in a radiological scenario. This is the first radiation metabolomics study in human urine laying the foundation for the use of metabolomics in biodosimetry and providing confidence in biomarker

  2. Past Exposure to Densely Ionizing Radiation Leaves a Unique Permanent Signature in the Genome

    PubMed Central

    Hande, M. Prakash; Azizova, Tamara V.; Geard, Charles R.; Burak, Ludmilla E.; Mitchell, Catherine R.; Khokhryakov, Valentin F.; Vasilenko, Evgeny K.; Brenner, David J.

    2003-01-01

    Speculation has long surrounded the question of whether past exposure to ionizing radiation leaves a unique permanent signature in the genome. Intrachromosomal rearrangements or deletions are produced much more efficiently by densely ionizing radiation than by chemical mutagens, x-rays, or endogenous aging processes. Until recently, such stable intrachromosomal aberrations have been very hard to detect, but a new chromosome band painting technique has made their detection practical. We report the detection and quantification of stable intrachromosomal aberrations in lymphocytes of healthy former nuclear-weapons workers who were exposed to plutonium many years ago. Even many years after occupational exposure, more than half the blood cells of the healthy plutonium workers contain large (>6 Mb) intrachromosomal rearrangements. The yield of these aberrations was highly correlated with plutonium dose to the bone marrow. The control groups contained very few such intrachromosomal aberrations. Quantification of this large-scale chromosomal damage in human populations exposed many years earlier will lead to new insights into the mechanisms and risks of cytogenetic damage. PMID:12679897

  3. Characterization of Ablation Product Radiation Signatures of PICA and FiberForm

    NASA Technical Reports Server (NTRS)

    Winter, Michael; Butler, Bradley D.; Diao, Zhaojin; Panerai, Francesco; Martin, Alexandre; Bailey, Sean C. C.; Danehy, Paul M.; Splinter, Scott

    2016-01-01

    Emission spectroscopy measurements in the post-shock layer in front of low density ablative material samples of different shapes were obtained in the NASA Langley HYMETS arcjet facility. A horizontal line of measurement positions was imaged on the entrance slit of the spectrometer allowing detection of the entire stagnation line in front of the samples. The stagnation line measurements were used to compare the post-shock layer emission signatures in front of PICA and FiberForm. The emission signatures of H, NH, and OH are characteristic for pyrolysis gases and consequently were only observed in front of the PICA samples. CN and C were found in front of both materials and are mainly due to interactions of the carbon fibers with the plasma. In all tests with instrumented samples, the emission of Mn, Cr, and Ni was observed when the thermocouple temperatures reached or exceeded 1,500 K, strongly indicating erosion of the molten thermocouple tips. Temperatures in the post-shock layer were estimated from comparing the CN band emission to spectral simulation. The resulting rotational and vibrational temperatures were on the order of 7,000 to 9,000 K and close to each other indicating a plasma condition close to equilibrium. In addition to the stagnation line configurations, off-axis lines of observation were investigated to gather information about spalled particles in the flow. From a comparison of measured continuum emission with simulated Planck radiation, average particle temperatures along the measured line of observation were determined for two cases. Particle temperatures between 3,500 and 2,000 K were found. A comprehensive investigation of the entire amount of data set is ongoing.

  4. Progress Toward an Updated National Solar Radiation Data Base

    SciTech Connect

    Wilcox, S.; Anderberg, M.; George, R.; Marion, W.; Myers, D.; Renne, D.; Beckman, W.; DeGaetano, A.; Gueymard, C.; Perez, R.; Plantico, M.; Stackhouse, P.; Vignola, F.

    2005-01-01

    Progress is reported on an updated National Solar Radiation Database (NSRDB). Focus on this year's work was on preparing a test-year database for evaluating several solar radiation models that could be used to replace the METSTAT model used in the original 1961-1990 NSRDB. That model is no longer compatible with cloud observations reported by the National Weather Service. We have also included a satellite-based model that will increase the spatial resolution of solar radiation for GIS or mapping applications. Work also included development of improved estimates for aerosols, water vapor, and ozone. High-quality solar measurements were obtained for 33 sites near National Weather Service stations, and model runs were completed for test years 1999 and 2000.

  5. MHD-based modeling of radiation and polarization signatures of blazar emission

    NASA Astrophysics Data System (ADS)

    Zhang, Haocheng; Li, Hui; Boettcher, Markus

    2016-04-01

    Observations have shown that sometimes strong multiwavelength flares are accompanied by drastic polarization variations, indicating active participation of magnetic fields during flares. We have developed a 3D numerical tool set of magnetohydrodynamics, Fokker-Planck particle evolution, and polarization-dependent radiation transfer codes. This allows us to study the snap-shot spectra, multiwavelength light curves, and time-dependent optical polarization signatures self-consistently. We have made a simultaneous fit of a multiwavelength flare with 180 degree polarization angle swing of the blazar 3C279 reported by Abdo et al. 2010. Our work has shown that this event requires an increase in the nonthermal particles, a decrease in the magnetic field strength, and a change in the magnetic field structure. We conclude that this event is likely due to a shock-initiated magnetic reconnection in an emission environment with relatively strong magnetic energy. We have performed magnetrohydrodynamic simulations to support this statement. Our simulations have found that the blazar emission region may be strongly magnetized. In this situation, polarization angle swings are likely to be correlated with strong gamma-ray flares.

  6. A Gene Expression and Pre-mRNA Splicing Signature That Marks the Adenoma-Adenocarcinoma Progression in Colorectal Cancer

    PubMed Central

    Pesson, Marine; Volant, Alain; Uguen, Arnaud; Trillet, Kilian; De La Grange, Pierre; Aubry, Marc; Daoulas, Mélanie; Robaszkiewicz, Michel; Le Gac, Gérald; Morel, Alain; Simon, Brigitte; Corcos, Laurent

    2014-01-01

    It is widely accepted that most colorectal cancers (CRCs) arise from colorectal adenomas (CRAs), but transcriptomic data characterizing the progression from colorectal normal mucosa to adenoma, and then to adenocarcinoma are scarce. These transition steps were investigated using microarrays, both at the level of gene expression and alternative pre-mRNA splicing. Many genes and exons were abnormally expressed in CRAs, even more than in CRCs, as compared to normal mucosae. Known biological pathways involved in CRC were altered in CRA, but several new enriched pathways were also recognized, such as the complement and coagulation cascades. We also identified four intersectional transcriptional signatures that could distinguish CRAs from normal mucosae or CRCs, including a signature of 40 genes differentially deregulated in both CRA and CRC samples. A majority of these genes had been described in different cancers, including FBLN1 or INHBA, but only a few in CRC. Several of these changes were also observed at the protein level. In addition, 20% of these genes (i.e. CFH, CRYAB, DPT, FBLN1, ITIH5, NR3C2, SLIT3 and TIMP1) showed altered pre-mRNA splicing in CRAs. As a global variation occurring since the CRA stage, and maintained in CRC, the expression and splicing changes of this 40-gene set may mark the risk of cancer occurrence from analysis of CRA biopsies. PMID:24516561

  7. Progress on an Updated National Solar Radiation Data Base: Preprint

    SciTech Connect

    Wilcox, S.; Anderberg, M.; George, R.; Marion, W.; Myers, D.; Renne, D.; Beckman, W.; DeGaetano, A.; Gueymard, C.; Perez, R.; Plantico, M.; Stackhouse, P.; Vignola, F.

    2004-03-01

    In 1992, The National Renewable Energy Laboratory (NREL) released the 1961-1990 National Solar Radiation Data Base (NSRDB), a 30-year set of hourly solar radiation data. In April 2003, NREL convened a meeting of experts to investigate issues concerning a proposed update of the NSRDB. The panel determined that an important difficulty posed by the update was the shift from manual to automated cloud observations at National Weather Service stations in the United States. The solar model used in the original NSRDB relied heavily on the methodology and resolution of the manual cloud observations. The meeting participants recommended that NREL produce a plan for creating an update using currently available meteorological observations and satellite imagery. This paper describes current progress toward a plan for an updated NSRDB.

  8. Radiation physics, biophysics, and radiation biology. Progress report, December 1, 1992--November 30, 1993

    SciTech Connect

    Hall, E.J.; Zaider, M.

    1993-05-01

    Research at the Center for Radiological Research is a multidisciplenary blend of physics, chemistry and biology aimed at understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. The focus is increased on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights of the program from the past year are described. A mathematical model describing the production of single-strand and double-strand breaks in DNA as a function radiation quality has been completed. For the first time Monte Carlo techniques have been used to obtain directly the spatial distribution of DNA moieties altered by radiation. This information was obtained by including the transport codes a realistic description of the electronic structure of DNA. We have investigated structure activity relationships for the potential oncogenicity of a new generation of bioreductive drugs that function as hypoxic cytotoxins. Experimental and theoretical investigation of the inverse dose rate effect, whereby medium LET radiations actually produce an c effect when the dose is protracted, is now at a point where the basic mechanisms are reasonably understood and the complex interplay between dose, dose rate and radiation quality which is necessary for the effect to be present can now be predicted at least in vitro. In terms of early radiobiological damage, a quantitative link has been established between basic energy deposition and locally multiply damaged sites, the radiochemical precursor of DNA double strand breaks; specifically, the spatial and energy deposition requirements necessary to form LMDs have been evaluated. For the first time, a mechanically understood ``biological fingerprint`` of high-LET radiation has been established. Specifically measurement of the ratio of inter-to intra-chromosomal aberrations produces a unique signature from alpha-particles or neutrons.

  9. Methods for optimization of the signature-based radiation scanning approach for detection of nitrogen-rich explosives

    NASA Astrophysics Data System (ADS)

    Callender, Kennard

    The signature-based radiation scanning (SBRS) technique can be used to rapidly detect nitrogen-rich explosives at standoff distances. This technique uses a template-matching procedure that produces a figure-of-merit (FOM) whose value is used to distinguish between inert and explosive materials. The present study develops a tiered-filter implementation of the signature-based radiation scanning technique, which reduces the number of templates needed. This approach starts by calculating a normalized FOM between signatures from an unknown target and an explosive template through stages or tiers (nitrogen first, then oxygen, then carbon, and finally hydrogen). If the normalized FOM is greater than a specified cut-off value for any of the tiers, the target signatures are considered not to match that specific template and the process is repeated for the next explosive template until all of the relevant templates have been considered. If a target's signatures match all the tiers of a single template, then the target is assumed to contain an explosive. The tiered filter approach uses eight elements to construct artificial explosive-templates that have the function of representing explosives cluttered with real materials. The feasibility of the artificial template approach to systematically build a library of templates that successfully differentiates explosive targets from inert ones in the presence of clutter and under different geometric configurations was explored. In total, 10 different geometric configurations were simulated and analyzed using the MCNP5 code. For each configuration, 51 different inert materials were used as inert samples and as clutter in front of the explosive cyclonite (RDX). The geometric configurations consisted of different explosive volumes, clutter thicknesses, and distances of the clutter from the neutron source. Additionally, an objective function was developed to optimize the parameters that maximize the sensitivity and specificity of the

  10. Microwave Signatures of Melting/Refreezing Snow: Observations and Modeling Using Dense Medium Radiative Transfer Theory

    NASA Technical Reports Server (NTRS)

    Tedesco, Marco; Kim, Edward J.; England, Anthony; deRoo, Roger; Hardy, Janet

    2005-01-01

    Microwave brightness temperatures of snow covered terrains can be modeled by means of the Dense Radiative Transfer Medium Theory (DMRT). In a dense medium, such as snow, the assumption of independent scattering is no longer valid and the scattering of correlated scatterers must be considered. In the DMRT, this is done considering a pair distribution function of the particles position. In the electromagnetic model, the snowpack is simulated as a homogeneous layer having effective permittivity and albedo calculated through the DMRT. In order to account for clustering of snow crystals, a model of cohesive particles can be applied, where the cohesion between the particles is described by means of a dimensionless parameters called stickiness (z), representing a measure of the inversion of the attraction of the particles. The lower the z the higher the stickiness. In this study, microwave signatures of melting and refreezing cycles of seasonal snowpacks at high altitudes are studied by means of both experimental and modeling tools. Radiometric data were collected 24 hours per day by the University of Michigan Tower Mounted Radiometer System (TMRS). The brightness temperatures collected by means of the TMRS are simulated by means of a multi-layer electromagnetic model based on the dense medium theory with the inputs to the model derived from the data collected at the snow pits and from the meteorological station. The paper is structured as follows: in the first Section the temperature profiles recorded by the meteorological station and the snow pit data are presented and analyzed; in the second Section, the characteristics of the radiometric system used to collect the brightness temperatures are reported together with the temporal behavior of the recorded brightness temperatures; in the successive Section the multi-layer DMRT-based electromagnetic model is described; in the fourth Section the comparison between modeled and measured brightness temperatures is discussed. We

  11. Effect of dihydroxyanthraquinone and radiation on G2 progression

    SciTech Connect

    Kimler, B.F.

    1980-01-01

    The effect of dihydroxyanthraquinone (DHAQ), a potential anticancer chemotherapeutic agent, on the progression of Chinese hamster ovary cells into mitosis and on the division delay induced by ionizing radiation was studied using the mitotic selection procedure for cell cycle analysis. Following the addition of DHAQ, the number of mitotic cells selected from an asynchronous population remained unaltered for a refractory period and then decreased. This effect was concentration dependent with transition points between the S/G2 boundary at 10(-4) micrograms/ml and the G2/M boundary at greater than or equal to 10(2) micrograms/ml. The duration of the transient division delay was dependent upon the concentration of drug used and the duration of pulse exposure. When cells were treated with pulses of DHAQ in addition to X-irradiation, there was no change in the location of the radiation transition point. There was an increase in the duration of division delay compared to that produced by X-ray alone that was dependent upon the concentration and duration of drug treatment. The effect of DHAW is similar to that of other cancer chemotherapeutic agents (Adriamycin, bleomycin, and lucanthone), and the same cautions should therefore be considered when combining DHAQ and radiation for clinical use.

  12. Progress in the Development of Volatile Exhaled Breath Signatures of Lung Cancer

    PubMed Central

    Wang, Xiao-Feng; Lim, Sung; Jett, James; Choi, Humberto; Zhang, Qi; Beukemann, Mary; Seeley, Meredith; Martino, Ray; Rhodes, Paul

    2015-01-01

    Rationale: Volatile organic compounds present in the exhaled breath have shown promise as biomarkers of lung cancer. Advances in colorimetric sensor array technology, breath collection methods, and clinical phenotyping may lead to the development of a more accurate breath biomarker. Objectives: Perform a discovery-level assessment of the accuracy of a colorimetric sensor array–based volatile breath biomarker. Methods: Subjects with biopsy-confirmed untreated lung cancer, and others at risk for developing lung cancer, performed tidal breathing into a breath collection instrument designed to expose a colorimetric sensor array to the alveolar portion of the breath. Random forest models were built from the sensor output of 70% of the study subjects and were tested against the remaining 30%. Models were developed to separate cancer and subgroups from control, and to characterize the cancer. Additional models were developed after matching the clinical phenotypes of cancer and control subjects. Measurements and Main Results: Ninety-seven subjects with lung cancer and 182 control subjects participated. The accuracies, reported as C-statistics, for models of cancer and subgroups versus control ranged from 0.794 to 0.861. The accuracy was improved by developing models for cancer and control groups selected through propensity matching for clinical variables. A model built using only subjects from the largest available clinical subgroup (49 subjects) had a C-statistic of 0.982. Models developed and tested to characterize cancer histology, and to compare early- with late-stage cancer, had C-statistics of 0.881–0.960. Conclusions: The colorimetric sensor array signature of exhaled breath volatile organic compounds was capable of distinguishing patients with lung cancer from clinically relevant control subjects in a discovery level trial. The incorporation of clinical phenotypes into the further development of this biomarker may optimize its accuracy. PMID:25965541

  13. Polarimetric signatures of a canopy of dielectric cylinders based on first and second order vector radiative transfer theory

    NASA Technical Reports Server (NTRS)

    Tsang, Leung; Chan, Chi Hou; Kong, Jin AU; Joseph, James

    1992-01-01

    Complete polarimetric signatures of a canopy of dielectric cylinders overlying a homogeneous half space are studied with the first and second order solutions of the vector radiative transfer theory. The vector radiative transfer equations contain a general nondiagonal extinction matrix and a phase matrix. The energy conservation issue is addressed by calculating the elements of the extinction matrix and the elements of the phase matrix in a manner that is consistent with energy conservation. Two methods are used. In the first method, the surface fields and the internal fields of the dielectric cylinder are calculated by using the fields of an infinite cylinder. The phase matrix is calculated and the extinction matrix is calculated by summing the absorption and scattering to ensure energy conservation. In the second method, the method of moments is used to calculate the elements of the extinction and phase matrices. The Mueller matrix based on the first order and second order multiple scattering solutions of the vector radiative transfer equation are calculated. Results from the two methods are compared. The vector radiative transfer equations, combined with the solution based on method of moments, obey both energy conservation and reciprocity. The polarimetric signatures, copolarized and depolarized return, degree of polarization, and phase differences are studied as a function of the orientation, sizes, and dielectric properties of the cylinders. It is shown that second order scattering is generally important for vegetation canopy at C band and can be important at L band for some cases.

  14. Gamma-Ray Signatures for State-Of-Health Analysis and Monitoring of Widely-Arrayed Radiation Portal Monitor Systems

    SciTech Connect

    Woodring, Mitchell L.; Ely, James H.; Angel, Linda K.; Wright, Ingrid H.; Eslinger, Melany A.; Pospical, A. Jill; Ellis, John E.

    2008-05-15

    Pacific Northwest National Laboratory (PNNL) has deployed a large array of radiation portal monitors for the Department of Homeland Security U.S. Customs and Border Protection. These portal monitors scan incoming vehicles crossing the U.S. border and shipping containers leaving international ports for radioactive material via gamma-ray and neutron detection. Data produced and captured by these systems are recorded for every vehicle related to radiation signature, sensor/system status, and local background, as well as a host of other variables. Within the Radiation Portal Monitor Project at PNNL, state-of-health observation and analysis for the whole RPM system using these data to determine functionality and performance is being developed. (PIET-43741-TM-492)

  15. Metabolomic signatures in lipid-loaded HepaRGs reveal pathways involved in steatotic progression

    PubMed Central

    Brown, MV; Compton, SA; Milburn, MV; Lawton, KA; Cheatham, B

    2013-01-01

    Objectives Non-alcoholic fatty liver disease (NAFLD) describes a spectrum of disorders including simple steatosis, non-alcoholic steatohepatitis, fibrosis, and cirrhosis. With the increased prevalence of obesity, and consequently NAFLD, there is a need for novel therapeutics in this area. To facilitate this effort, we developed a cellular model of hepatic steatosis using HepaRG cells and determined the resulting biochemical alterations. Design and methods Using global metabolomic profiling, by means of a novel metabolite extraction procedure, we examined the metabolic profiles in response to the saturated fatty acid palmitate, and a mixture of saturated and unsaturated fatty acids, palmitate and oleate (1:2). Results We observed elevated levels of the branched chain amino acids, TCA cycle intermediates, sphingosine and acylcarnitines, and reduced levels of carnitine in the steatotic HepaRG model with both palmitate and palmitate:oleate treatments. In addition, palmitate-induced steatotic cells selectively displayed elevated levels of diacylglycerols and monoacylglycerols, as well as altered bile acid metabolism. Conclusion This global metabolomics approach reveals biochemical changes in pathways important in the transition to hepatic steatosis including insulin resistance, altered mitochondrial metabolism, and oxidative stress. Moreover, our data demonstrate the utility of this in vitro model for investigating mechanisms of steatotic progression, insulin resistance and lipotoxicity in NAFLD. PMID:23512965

  16. Obesity dependent metabolic signatures associated with nonalcoholic fatty liver disease progression

    PubMed Central

    Barr, J.; Caballería, J.; Martínez-Arranz, I.; Domínguez-Díez, A.; Alonso, C.; Muntané, J.; Pérez-Cormenzana, M.; García-Monzón, C.; Mayo, R.; Martín-Duce, A.; Romero-Gómez, M.; Iacono, O. Lo; Tordjman, J.; Andrade, R.J.; Pérez-Carreras, M.; Le Marchand-Brustel, Y.; Tran, A.; Fernández-Escalante, C.; Arévalo, E.; García–Unzueta, M.; Clement, K.; Crespo, J.; Gual, P.; Gómez-Fleitas, M.; Martínez-Chantar, M.L.; Castro, A.; Lu, S.C.; Vázquez-Chantada, M.; Mato, J.M.

    2012-01-01

    Our understanding of the mechanisms by which nonalcoholic fatty liver disease (NAFLD) progresses from simple steatosis to steatohepatitis (NASH) is still very limited. Despite the growing number of studies linking the disease with altered serum metabolite levels, an obstacle to the development of metabolome-based NAFLD predictors has been the lack of large cohort data from biopsy-proven patients matched for key metabolic features such as obesity. We studied 467 biopsied individuals with normal liver histology (n=90) or diagnosed with NAFLD (steatosis, n=246; NASH, n=131), randomly divided into estimation (80% of all patients) and validation (20% of all patients) groups. Qualitative determinations of 540 serum metabolite variables were performed using ultra-performance liquid chromatography coupled to mass spectrometry (UPLC-MS). The metabolic profile was dependent on patient body-mass index (BMI), suggesting that the NAFLD pathogenesis mechanism may be quite different depending on an individual’s level of obesity. A BMI-stratified multivariate model based on the NAFLD serum metabolic profile was used to separate patients with and without NASH. The area under the receiver operating characteristic curve was 0.87 in the estimation and 0.85 in the validation group. The cutoff (0.54) corresponding to maximum average diagnostic accuracy (0.82) predicted NASH with a sensitivity of 0.71 and a specificity of 0.92 (negative/positive predictive values = 0.82/0.84). The present data, indicating that a BMI-dependent serum metabolic profile may be able to reliably distinguish NASH from steatosis patients, have significant implications for the development of NASH biomarkers and potential novel targets for therapeutic intervention. PMID:22364559

  17. Induction of the intestinal stem cell signature gene SMOC-2 is required for L1-mediated colon cancer progression.

    PubMed

    Shvab, A; Haase, G; Ben-Shmuel, A; Gavert, N; Brabletz, T; Dedhar, S; Ben-Ze'ev, A

    2016-02-01

    Overactivation of Wnt-β-catenin signaling, including β-catenin-TCF target gene expression, is a hallmark of colorectal cancer (CRC) development. We identified the immunoglobulin family of cell-adhesion receptors member L1 as a β-catenin-TCF target gene preferentially expressed at the invasive edge of human CRC tissue. L1 can confer enhanced motility and liver metastasis when expressed in CRC cells. This ability of L1-mediated metastasis is exerted by a mechanism involving ezrin and the activation of NF-κB target genes. In this study, we identified the secreted modular calcium-binding matricellular protein-2 (SMOC-2) as a gene activated by L1-ezrin-NF-κB signaling. SMOC-2 is also known as an intestinal stem cell signature gene in mice expressing Lgr5 in cells at the bottom of intestinal crypts. The induction of SMOC-2 expression in L1-expressing CRC cells was necessary for the increase in cell motility, proliferation under stress and liver metastasis conferred by L1. SMOC-2 expression induced a more mesenchymal like phenotype in CRC cells, a decrease in E-cadherin and an increase in Snail by signaling that involves integrin-linked kinase (ILK). SMOC-2 was localized at the bottom of normal human colonic crypts and at increased levels in CRC tissue with preferential expression in invasive areas of the tumor. We found an increase in Lgr5 levels in CRC cells overexpressing L1, p65 or SMOC-2, suggesting that L1-mediated CRC progression involves the acquisition of a stem cell-like phenotype, and that SMOC-2 elevation is necessary for L1-mediated induction of more aggressive/invasive CRC properties. PMID:25915847

  18. The potential influence of radiation-induced microenvironments in neoplastic progression

    NASA Technical Reports Server (NTRS)

    Barcellos-Hoff, M. H.; Chatterjee, A. (Principal Investigator)

    1998-01-01

    Ionizing radiation is a complete carcinogen, able both to initiate and promote neoplastic progression and is a known carcinogen of human and murine mammary gland. Tissue response to radiation is a composite of genetic damage, cell death and induction of new gene expression patterns. Although DNA damage is believed to initiate carcinogenesis, the contribution of these other aspects of radiation response are beginning to be explored. Our studies demonstrate that radiation elicits rapid and persistent global alterations in the mammary gland microenvironment. We postulate that radiation-induced microenvironments may affect epithelial cells neoplastic transformation by altering their number or susceptibility. Alternatively, radiation induced microenvironments may exert a selective force on initiated cells and/or be conducive to progression. A key impetus for these studies is the possibility that blocking these events could be a strategy to interrupt neoplastic progression.

  19. Radiative neutrino mass with ℤ 3 dark matter: from relic density to LHC signatures

    NASA Astrophysics Data System (ADS)

    Ding, Ran; Han, Zhi-Long; Liao, Yi; Xie, Wan-Peng

    2016-05-01

    In this work we give a comprehensive analysis on the phenomenology of a specific ℤ 3 dark matter (DM) model in which neutrino mass is induced at two loops by interactions with a DM particle that can be a complex scalar or a Dirac fermion. Both the DM properties in relic density and direct detection and the LHC signatures are examined in great detail, and indirect detection for gamma-ray excess from the Galactic Center is also discussed briefly. On the DM side, both semi-annihilation and co-annihilation processes play a crucial role in alleviating the tension of parameter space between relic density and direct detection. On the collider side, new decay channels resulting from ℤ 3 particles lead to distinct signals at LHC. Currently the trilepton signal is expected to give the most stringent bound for both scalar and fermion DM candidates, and the signatures of fermion DM are very similar to those of electroweakinos in simplified supersymmetric models.

  20. Expression signature distinguishing two tumour transcriptome classes associated with progression-free survival among rare histological types of epithelial ovarian cancer

    PubMed Central

    Wang, Chen; Winterhoff, Boris J; Kalli, Kimberly R; Block, Matthew S; Armasu, Sebastian M; Larson, Melissa C; Chen, Hsiao-Wang; Keeney, Gary L; Hartmann, Lynn C; Shridhar, Viji; Konecny, Gottfried E; Goode, Ellen L; Fridley, Brooke L

    2016-01-01

    Background: The mechanisms of recurrence have been under-studied in rare histologies of invasive epithelial ovarian cancer (EOC) (endometrioid, clear cell, mucinous, and low-grade serous). We hypothesised the existence of an expression signature predictive of outcome in the rarer histologies. Methods: In split discovery and validation analysis of 131 Mayo Clinic EOC cases, we used clustering to determine clinically relevant transcriptome classes using microarray gene expression measurements. The signature was validated in 967 EOC tumours (91 rare histological subtypes) with recurrence information. Results: We found two validated transcriptome classes associated with progression-free survival (PFS) in the Mayo Clinic EOC cases (P=8.24 × 10−3). This signature was further validated in the public expression data sets involving the rare EOC histologies, where these two classes were also predictive of PFS (P=1.43 × 10−3). In contrast, the signatures were not predictive of PFS in the high-grade serous EOC cases. Moreover, genes upregulated in Class-1 (with better outcome) were showed enrichment in steroid hormone biosynthesis (false discovery rate, FDR=0.005%) and WNT signalling pathway (FDR=1.46%); genes upregulated in Class-2 were enriched in cell cycle (FDR=0.86%) and toll-like receptor pathways (FDR=2.37%). Conclusions: These findings provide important biological insights into the rarer EOC histologies that may aid in the development of targeted treatment options for the rarer histologies. PMID:27253175

  1. Signatures support program

    NASA Astrophysics Data System (ADS)

    Hawley, Chadwick T.

    2009-05-01

    The Signatures Support Program (SSP) leverages the full spectrum of signature-related activities (collections, processing, development, storage, maintenance, and dissemination) within the Department of Defense (DOD), the intelligence community (IC), other Federal agencies, and civil institutions. The Enterprise encompasses acoustic, seismic, radio frequency, infrared, radar, nuclear radiation, and electro-optical signatures. The SSP serves the war fighter, the IC, and civil institutions by supporting military operations, intelligence operations, homeland defense, disaster relief, acquisitions, and research and development. Data centers host and maintain signature holdings, collectively forming the national signatures pool. The geographically distributed organizations are the authoritative sources and repositories for signature data; the centers are responsible for data content and quality. The SSP proactively engages DOD, IC, other Federal entities, academia, and industry to locate signatures for inclusion in the distributed national signatures pool and provides world-wide 24/7 access via the SSP application.

  2. A 7-gene signature of the recipient predicts the progression of fibrosis after liver transplantation for hepatitis C virus infection.

    PubMed

    do O, Nicole T; Eurich, Dennis; Schmitz, Petra; Schmeding, Maximilian; Heidenhain, Christoph; Bahra, Marcus; Trautwein, Christian; Neuhaus, Peter; Neumann, Ulf P; Wasmuth, Hermann E

    2012-03-01

    Fibrosis recurrence after liver transplantation (LT) for hepatitis C virus (HCV) is a universal event and strongly determines a patient's prognosis. The recipient risk factors for fibrosis recurrence are still poorly defined. Here we assess a genetic risk score as a predictor of fibrosis after LT. The cirrhosis risk score (CRS), which comprises allele variants in 7 genes (adaptor-related protein complex 3 S2, aquaporin 2, antizyme inhibitor 1, degenerative spermatocyte homolog 1 lipid desaturase, syntaxin binding protein 5-like, toll-like receptor 4, and transient receptor potential cation channel M5), was calculated for 137 patients who underwent LT for HCV infection and experienced HCV reinfection of the graft. The patients were stratified into 3 CRS categories: <0.5, 0.5 to 0.7, and >0.7. All patients underwent protocol biopsy after LT (median follow-up = 5 years), and liver fibrosis was assessed according to the Desmet and Scheuer score. The data were analyzed with univariate and multivariate analyses. The results showed that the highest CRS category was strongly associated with the presence of F2 or F3 fibrosis in protocol biopsy samples 1, 3, and 5 years after LT (P = 0.006, P = 0.001, and P = 0.02, respectively). Overall, 75.0% of the patients with a CRS > 0.7 developed at least F2 fibrosis, whereas 51.5% developed F3 fibrosis during follow-up. The predictive value of the CRS for fibrosis progression was independent of known clinical risk factors, including the age of the donor, the sex of the recipient, and the occurrence of acute rejection. A Kaplan-Meier analysis confirmed the prognostic value of the CRS with respect to the recurrence of severe liver fibrosis in HCV-infected patients after LT (log rank = 6.23, P = 0.03). In conclusion, the genetic signature of the recipient predicts the likelihood of severe liver fibrosis in the graft after HCV recurrence. The CRS might help with early clinical decision making (eg, the selection of patients for antiviral

  3. The optical and radiation field signatures produced by lightning return strokes

    NASA Technical Reports Server (NTRS)

    Guo, C.; Krider, E. P.

    1982-01-01

    Typical examples of the signals that are produced by first and subsequent return strokes in cloud-to-ground lightning on a microsecond time scale are presented. Statistics on the structure of the waveforms and the radiance of the channels are given. The relationship between the light signals and the associated electric field signatures is discussed. It is shown that the initial light signal from a return stroke tends to be linear for about 15 microsec and then rises more slowly to a peak that is delayed by approximately 60 microsec from the electric field peak. It is thought that the transition between the fast linear portion and the slower rise may be due to the return stroke entering the cloud base. A small percentage of the records suggest that two different branches of the same stepped leader can initiate separate return strokes. The light pulses from cloud discharges tend to be smaller and to vary more slowly than those from return strokes.

  4. PROGRESS REPORT. RADIATION EFFECTS IN NUCLEAR WASTE MATERIALS

    EPA Science Inventory

    The objective of this project is to develop a fundamental understanding of radiation effects in glasses and ceramics, as well as the influence of solid-state radiation effects on aqueous dissolution kinetics. This study will provide the underpinning science to develop improved gl...

  5. Spectral Signature of Column Solar Radiation Absorption During the Atmospheric Radiation Measurement Enhanced Shortwave Experiment (ARESE). Revision

    SciTech Connect

    O'Hirok, William; Gautier, Catherine; Ricchiazzi, Paul

    1999-11-01

    Spectral and broadband shortwave radiative flux data obtained from the Atmospheric Radiation Measurement Enhanced Shortwave Experiment (ARESE) are compared with 3-D radiative transfer computations for the cloud field of October 30, 1995. Because the absorption of broadband solar radiation in the cloudy atmosphere deduced from observations and modeled differ by 135 Wm{sup -2}, we performed a consistency analysis using spectral observations and the model to integrate for wavelengths between the spectral observations. To match spectral measurements, aerosols need a reduction in both single scattering albedo (from 0.938 to 0.82) and asymmetry factor (from 0.67 to 0.61), and cloud droplets require a three-fold increase in co-albedo. Even after modifying the model inputs and microphysics the difference in total broadband absorption is still of the order of 75Wm{sup -2}. Finally, an unexplained absorber centered around 1.06 {micro}m appears in the comparison that is much too large to be explained by dimers.

  6. Radiative Signatures of Reconnection in X-ray Binary Spectral States

    NASA Astrophysics Data System (ADS)

    Uzdensky, Dmitri

    Accreting black holes (BHs) in Galactic X-ray Binary (XRB) systems represent some of the main targets of space-based high-energy observatories such as NASA s RXTE, Chandra, and NuSTAR, as well as the international observatories XMM Newton, INTEGRAL, Suzaku (Astro-E), and Astro-H. The overall radiative energy output (mostly X-rays) is ultimately powered by the conversion of the gravitational potential energy of the matter falling onto a black hole and forming an accretion disk or a hot accretion flow around it. Observationally, these systems are found to cycle between a few discrete spectral states, characterized by different overall X-ray power and spectral hardness: (1) the bright thermal high-soft state, dominated by a soft (1 keV) thermal component attributed to a thin dense accretion disk with a relatively weak corona producing a power-law tail emission to at least 1 MeV; (2) the low-hard state, showing no signs of a thin accretion disk and dominated by a single hard (with index ~ -1.7) power law truncating at about 100 keV; and (3) the bright Steep Power Law state with both a standard thin disk and a powerful coronal power-law (with index about -2.5) emission extending to at least 1 MeV. Explaining the key features of these nonthermal spectra, i.e., their power law indices and high-energy cutoffs, is one of the outstanding problems in high-energy astrophysics. The hard (10keV 1MeV) X-ray emission in these states is believed to be produced by inverse-Compton scattering in relativistically-hot gas, presumably heated by magnetic reconnection processes, and forming either an accretion disk corona or the hot accretion flow itself. Since the radiative cooling time of the energetic electrons in the intense radiation fields found in these systems is very short, the observed non-thermal hard X-ray spectra should directly reflect the instantaneous energy spectra of the electrons accelerated in reconnection events. Recent advances in kinetic simulations of reconnection

  7. Biochemical signatures of in vitro radiation response in human lung, breast and prostate tumour cells observed with Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Matthews, Q.; Jirasek, A.; Lum, J. J.; Brolo, A. G.

    2011-11-01

    This work applies noninvasive single-cell Raman spectroscopy (RS) and principal component analysis (PCA) to analyze and correlate radiation-induced biochemical changes in a panel of human tumour cell lines that vary by tissue of origin, p53 status and intrinsic radiosensitivity. Six human tumour cell lines, derived from prostate (DU145, PC3 and LNCaP), breast (MDA-MB-231 and MCF7) and lung (H460), were irradiated in vitro with single fractions (15, 30 or 50 Gy) of 6 MV photons. Remaining live cells were harvested for RS analysis at 0, 24, 48 and 72 h post-irradiation, along with unirradiated controls. Single-cell Raman spectra were acquired from 20 cells per sample utilizing a 785 nm excitation laser. All spectra (200 per cell line) were individually post-processed using established methods and the total data set for each cell line was analyzed with PCA using standard algorithms. One radiation-induced PCA component was detected for each cell line by identification of statistically significant changes in the PCA score distributions for irradiated samples, as compared to unirradiated samples, in the first 24-72 h post-irradiation. These RS response signatures arise from radiation-induced changes in cellular concentrations of aromatic amino acids, conformational protein structures and certain nucleic acid and lipid functional groups. Correlation analysis between the radiation-induced PCA components separates the cell lines into three distinct RS response categories: R1 (H460 and MCF7), R2 (MDA-MB-231 and PC3) and R3 (DU145 and LNCaP). These RS categories partially segregate according to radiosensitivity, as the R1 and R2 cell lines are radioresistant (SF2 > 0.6) and the R3 cell lines are radiosensitive (SF2 < 0.5). The R1 and R2 cell lines further segregate according to p53 gene status, corroborated by cell cycle analysis post-irradiation. Potential radiation-induced biochemical response mechanisms underlying our RS observations are proposed, such as (1) the regulated

  8. Recent progress in the development of transition radiation detectors

    NASA Technical Reports Server (NTRS)

    Cherry, M. L.; Hartmann, G.; Prince, T.; Mueller, D.

    1978-01-01

    Transition-radiation detectors have been used in several recent cosmic-ray experiments for particle identification at energies E/mc-squared of at least about 1000. In order to optimize the design of such detectors and to use them for energy measurements over a broad energy range, it is necessary to study the details of the transition-radiation process. Experimental results are presented which test the theoretical predictions more precisely and at higher energies than in previous experiments. The dependence of the interference pattern in the frequency spectrum on the radiator dimensions is studied, and the total transition-radiation yield generated by electrons in various radiators is measured over a very wide energy range, from 5 to 300 GeV. The significance of the individual experimental parameters in the design of transition radiation detectors is reviewed, and the characteristics of transition-radiation detectors capable of measuring particle energies over the range E/mc-squared from about 300 to 100,000 are discussed.

  9. Wave like signatures in aerosol optical depth and associated radiative impacts over the central Himalayan region

    SciTech Connect

    Shukla, K. K.; Phanikumar, D. V.; Kumar, K.  Niranjan; Reddy, Kishore; Kotamarthi, V. R.; Newsom, Rob K.; Ouarda, Taha B. M. J.

    2015-10-01

    In this study, we present a case study on 16 October 2011 to show the first observational evidence of the influence of short period gravity waves in aerosol transport during daytime over the central Himalayan region. The Doppler lidar data has been utilized to address the daytime boundary layer evolution and related aerosol dynamics over the site. Mixing layer height is estimated by wavelet covariance transform method and found to be ~ 0.7 km, AGL. Aerosol optical depth observations during daytime revealed an asymmetry showing clear enhancement during afternoon hours as compared to forenoon. Interestingly, Fourier and wavelet analysis of vertical velocity and attenuated backscatter showed similar 50-90 min short period gravity wave signatures during afternoon hours. Moreover, our observations showed that gravity waves are dominant within the boundary layer implying that the daytime boundary layer dynamics is playing a vital role in transporting the aerosols from surface to the top of the boundary layer. Similar modulations are also evident in surface parameters like temperature, relative humidity and wind speed indicating these waves are associated with the dynamical aspects over Himalayan region. Finally, time evolution of range-23 height indicator snapshots during daytime showed strong upward velocities especially during afternoon hours implying that convective processes through short period gravity waves plays a significant role in transporting aerosols from the nearby valley region to boundary layer top over the site. These observations also establish the importance of wave induced daytime convective boundary layer dynamics in the lower Himalayan region.

  10. Symposium Papers-Progress in Radiation and Energy Balance Measurement Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    On November 2, 2004, an all-day symposium entitled “Progress in Radiation and Energy Balance Measurement Systems” was convened at the ASA-CSSA-SSSA annual meetings in Seattle, WA. Interest in the measurement of radiation and energy balance components at soil and plant canopy surfaces has seen a res...

  11. National Council on Radiation Protection and Measurements semiannual technical progress report, March 1989--August 1989

    SciTech Connect

    Ney, W.R.

    1991-01-01

    This semiannual technical progress report is for the period 1 March 1989 through 31 August 1989. This National Council on Radiation Protection and Measurements (NCRP) program is designed to provide recommendations for radiation protection based on scientific principles. During this period several reports were published covering the topics of occupational radiation exposure, medical exposure, radon control, dosimetry, and radiation protection standards. Accomplishments of various committees are also reported; including the committees on dental x-ray protection, radiation safety in uranium mining and milling, ALARA, instrumentation, records maintenance, occupational exposures of medical personnel, emergency planning, and others. (SM)

  12. Recent progress in the transition radiation detector techniques

    NASA Technical Reports Server (NTRS)

    Yuan, L. C. L.

    1973-01-01

    A list of some of the major experimental achievements involving charged particles in the relativistic region are presented. With the emphasis mainly directed to the X-ray region, certain modes of application of the transition radiation for the identification and separation of relativistic charged particles are discussed. Some recent developments in detection techniques and improvements in detector performances are presented. Experiments were also carried out to detect the dynamic radiation, but no evidence of such an effect was observed.

  13. Advanced multimodal nanoparticles delay tumor progression with clinical radiation therapy.

    PubMed

    Detappe, Alexandre; Kunjachan, Sijumon; Sancey, Lucie; Motto-Ros, Vincent; Biancur, Douglas; Drane, Pascal; Guieze, Romain; Makrigiorgos, G Mike; Tillement, Olivier; Langer, Robert; Berbeco, Ross

    2016-09-28

    Radiation therapy is a major treatment regimen for more than 50% of cancer patients. The collateral damage induced on healthy tissues during radiation and the minimal therapeutic effect on the organ-of-interest (target) is a major clinical concern. Ultra-small, renal clearable, silica based gadolinium chelated nanoparticles (SiGdNP) provide simultaneous MR contrast and radiation dose enhancement. The high atomic number of gadolinium provides a large photoelectric cross-section for increased photon interaction, even for high-energy clinical radiation beams. Imaging and therapy functionality of SiGdNP were tested in cynomolgus monkeys and pancreatic tumor-bearing mice models, respectively. A significant improvement in tumor cell damage (double strand DNA breaks), growth suppression, and overall survival under clinical radiation therapy conditions were observed in a human pancreatic xenograft model. For the first time, safe systemic administration and systematic renal clearance was demonstrated in both tested species. These findings strongly support the translational potential of SiGdNP for MR-guided radiation therapy in cancer treatment. PMID:27423325

  14. Magnetic flux emergence in granular convection: radiative MHD simulations and observational signatures

    NASA Astrophysics Data System (ADS)

    Cheung, M. C. M.; Schüssler, M.; Moreno-Insertis, F.

    2007-05-01

    Aims:We study the emergence of magnetic flux from the near-surface layers of the solar convection zone into the photosphere. Methods: To model magnetic flux emergence, we carried out a set of numerical radiative magnetohydrodynamics simulations. Our simulations take into account the effects of compressibility, energy exchange via radiative transfer, and partial ionization in the equation of state. All these physical ingredients are essential for a proper treatment of the problem. Furthermore, the inclusion of radiative transfer allows us to directly compare the simulation results with actual observations of emerging flux. Results: We find that the interaction between the magnetic flux tube and the external flow field has an important influence on the emergent morphology of the magnetic field. Depending on the initial properties of the flux tube (e.g. field strength, twist, entropy etc.), the emergence process can also modify the local granulation pattern. The emergence of magnetic flux tubes with a flux of 1019 Mx disturbs the granulation and leads to the transient appearance of a dark lane, which is coincident with upflowing material. These results are consistent with observed properties of emerging magnetic flux. Movies are only available in electronic form at http://www.aanda.org

  15. Progress and controversies: Radiation therapy for prostate cancer.

    PubMed

    Martin, Neil E; D'Amico, Anthony V

    2014-01-01

    Radiation therapy remains a standard treatment option for men with localized prostate cancer. Alone or in combination with androgen-deprivation therapy, it represents a curative treatment and has been shown to prolong survival in selected populations. In this article, the authors review recent advances in prostate radiation-treatment techniques, photon versus proton radiation, modification of treatment fractionation, and brachytherapy-all focusing on disease control and the impact on morbidity. Also discussed are refinements in the risk stratification of men with prostate cancer and how these are better for matching patients to appropriate treatment, particularly around combined androgen-deprivation therapy. Many of these advances have cost and treatment burden implications, which have significant repercussions given the prevalence of prostate cancer. The discussion includes approaches to improve value and future directions for research. PMID:25234700

  16. Axions and saxions from the primordial supersymmetric plasma and extra radiation signatures

    SciTech Connect

    Graf, Peter; Steffen, Frank Daniel E-mail: steffen@mpp.mpg.de

    2013-02-01

    We calculate the rate for thermal production of axions and saxions via scattering of quarks, gluons, squarks, and gluinos in the primordial supersymmetric plasma. Systematic field theoretical methods such as hard thermal loop resummation are applied to obtain a finite result in a gauge-invariant way that is consistent to leading order in the strong gauge coupling. We calculate the thermally produced yield and the decoupling temperature for both axions and saxions. For the generic case in which saxion decays into axions are possible, the emitted axions can constitute extra radiation already prior to big bang nucleosynthesis and well thereafter. We update associated limits imposed by recent studies of the primordial helium-4 abundance and by precision cosmology of the cosmic microwave background and large scale structure. We show that the trend towards extra radiation seen in those studies can be explained by late decays of thermal saxions into axions and that upcoming Planck results will probe supersymmetric axion models with unprecedented sensitivity.

  17. IMRT (intensity modulated radiation therapy): progress in technology and reimbursement.

    PubMed

    Young, R; Snyder, B

    2001-01-01

    For a new treatment technology to become widely accepted in today's healthcare environment, the technology must not only be effective but also financially viable. Intensity modulated radiation therapy (IMRT), a technology that enables radiation oncologists to precisely target and attack cancerous tumors with higher doses of radiation using strategically positioned beams while minimizing collateral damage to healthy cells, now meets both criteria. With IMRT, radiation oncologists for the first time have obtained the ability to divide the treatment field covered by each beam angle into hundreds of segments as small as 2.5 mm by 5 mm. Using the adjustable leaves of an MLC to shape the beam and by controlling exposure times, physicians can deliver a different dose to each segment and therefore modulate dose intensity across the entire treatment field. Development of optimal IMRT plans using conventional manual treatment planning methods would take days. To be clinically practical, IMRT required the development of "inverse treatment planning" software. With this software, a radiation oncologist can prescribe the ideal radiation dose for a specific tumor as well as maximum dose limits for surrounding healthy tissue. These numbers are entered into the treatment planning program which then calculates the optimal delivery approach that will best fit the oncologist's requirements. The radiation oncologist then reviews and approves the proposed treatment plan before it is initiated. The most recent advance in IMRT technology offers a "dynamic" mode or "sliding window" technique. In this more rapid delivery method, the beam remains on while the leaves of the collimator continually re-shape and move the beam aperture over the planned treatment area. This creates a moving beam that saturates the tumor volume with the desired radiation dose while leaving the surrounding healthy tissue in a protective shadow created by the leaves of the collimator. In the dynamic mode, an IMRT

  18. Observable signatures of a black hole ejected by gravitational-radiation recoil in a galaxy merger.

    PubMed

    Loeb, Abraham

    2007-07-27

    According to recent simulations, the coalescence of two spinning black holes (BHs) could lead to a BH remnant with recoil speeds of up to thousands of km s(-1). Here we examine the circumstances resulting from a gas-rich galaxy merger under which the ejected BH would carry an accretion disk and be observable. As the initial BH binary emits gravitational radiation and its orbit tightens, a hole is opened in the disk which delays the consumption of gas prior to the eventual BH ejection. The punctured disk remains bound to the ejected BH within the region where the gas orbital velocity is larger than the ejection speed. For a approximately 10(7) M[middle dot in circle] BH the ejected disk has a characteristic size of tens of thousands of Schwarzschild radii and an accretion lifetime of approximately 10(7) yr. During that time, the ejected BH could traverse a considerable distance and appear as an off-center quasar with a feedback trail along the path it left behind. PMID:17678347

  19. Genomic signatures of chromosomal instability and osteosarcoma progression detected by high resolution array CGH and interphase FISH.

    PubMed

    Selvarajah, S; Yoshimoto, M; Ludkovski, O; Park, P C; Bayani, J; Thorner, P; Maire, G; Squire, J A; Zielenska, M

    2008-01-01

    Osteosarcoma (OS) is characterized by an unstable karyotype which typically has a heterogeneous pattern of complex chromosomal abnormalities. High-resolution array comparative genomic hybridization (CGH) in combination with interphase fluorescence in situ hybridization (FISH) analyses provides a complete description of genomic imbalances together with an evaluation of the contribution of cell-to-cell variation to copy number changes. There have been no analyses to date documenting genomic signatures consistent with chromosomal instability mechanisms in OS tumors using array CGH. In this study, we utilized high-resolution array CGH to identify and characterize recurrent signatures of genomic imbalances using ten OS tumors. Comparison between the genomic profiles identified tumor groups with low, intermediate and high levels of genomic imbalance. Bands 6p22-->p21, 8q24 and 17p12--> p11.2 were consistently involved in high copy gain or amplification events. Since these three locations have been consistently associated with OS oncogenesis, FISH probes from each cytoband were used to derive an index of cellular heterogeneity for copy number within each region. OS with the highest degree of genomic imbalance also exhibited the most extreme cell-to-cell copy number variation. Significantly, the three OS with the most imbalance and genomic copy number heterogeneity also had the poorest response to preoperative chemotherapy. This genome wide analysis is the first utilizing oligonucleotide array CGH in combination with FISH analysis to derive genomic signatures of chromosomal instability in OS tumors by studying genomic imbalance and intercellular heterogeneity. This comprehensive genomic screening approach provides important insights concerning the mechanisms responsible for generating complex genomes. The resulting phenotypic diversity can generate tumors with a propensity for an aggressive disease course. A better understanding of the underlying mechanisms leading to OS

  20. Narrow Radiative Recombination Continua: A Signature of Ions Crossing the Contact Discontinuity of Astrophysical Shocks

    NASA Technical Reports Server (NTRS)

    Behar, Ehud; Nordon, Raanan; Soker, Noam; Kastner, Joel H.; Yu, Young Sam

    2009-01-01

    X-rays from planetary nebulae (PNs) are believed to originate from a shock driven into the fast stellar wind (v 1000 kilometers per second) as it collides with an earlier circumstellar slow wind (v 10 kilometers per second). In theory, the shocked fast wind (hot hubble) and the ambient cold nebula can remain separated by magnetic fields along a surface referred to as the contact discontinuity (CD) that inhibits diffusion and heat conduction. The CD region is extremely difficult to probe directly owing to its small size and faint emission. This has largely left the study of CDs, stellar-shocks, and the associated micro-physics in the realm of theory. This paper presents spectroscopic evidence for ions from the hot bubble (kT approximately equal to 100 eV) crossing the CD and penetrating the cold nebular gas (kT approximately equal to 1 eV). Specifically, a narrow radiative recombination continuum (RRC) emission feature is identified in the high resolution X-ray spectrum of the PN BD+30degree3639 indicating bare C VII ions are recombining with cool electrons at kT(sub e) = 1.7 plus or minus 1.3 eV. An upper limit to the flux of the narrow RRC of H-like C VI is obtained as well. The RRCs are interpreted as due to C ions from the hot bubble of BD+30degree3639 crossing the CD into the cold nebula, where they ultimately recombine with its cool electrons. The RRC flux ratio of C VII to C VI constrains the temperature jump across the CD to deltakT greater than 80 eV, providing for the first time direct evidence for the stark temperature disparity between the two sides of an astrophysical CD, and constraining the role of magnetic fields and heat conduction accordingly. Two colliding-wind binaries are noted to have similar RRCs suggesting a temperature jump and CD crossing by ions may be common feature of stellar wind shocks.

  1. Silicon space solar cells: progression and radiation-resistance analysis

    NASA Astrophysics Data System (ADS)

    Rehman, Atteq ur; Lee, Sang Hee; Lee, Soo Hong

    2016-02-01

    In this paper, an overview of the solar cell technology based on silicon for applications in space is presented. First, the space environment and its effects on the basis of satellite orbits, such as geostationary earth orbit (GEO) and low earth orbit (LEO), are described. The space solar cell technology based on silicon-based materials, including thin-film silicon solar cells, for use in space was appraised. The evolution of the design for silicon solar cell for use in space, such as a backsurface field (BSF), selective doping, and both-side passivation, etc., is illustrated. This paper also describes the nature of radiation-induced defects and the models proposed for understanding the output power degradation in silicon space solar cells. The phenomenon of an anomalous increase in the short-circuit current ( I sc) in the fluence irradiation range from 2 × 1016 cm-2 to 5 × 1016 cm-2 is also described explicitly from the view point of the various presented models.

  2. Further progress in the characterisation of complex radiation fields.

    PubMed

    Spurny, Frantisek; Silari, Marco

    2008-01-01

    One of the topics which forms part of CONRAD project addresses the problems related to the dosimetry of complex-mixed radiation fields at workplaces. This topic was included in work package (WP) 6. WP 6 was established to co-ordinate research activities in two areas:the development of new techniques and the improvement of current techniques for characterisation of complex workplace fields (including high-energy fields and pulsed fields): measurement and calculation of particle energy and direction distributions (Subgroup A); and model improvements for dose assessment of solar particle events (Subgroup B). In both cases in order to aid the research, WP 6 increases the efficiency of resource utilisation, and facilitates the technology transfer to practical application and for the development of standards. This contribution presents a general overview of activities of SG A; specific results related to the benchmark experiment at GSI Darmstadt are presented separately, and will be published in other way. As far as the results acquired in the frame of the SG B activities, these are presented in the meeting held as part of EURADOS AM 2008. PMID:18718960

  3. Fifty years of progress in radiation therapy for breast cancer.

    PubMed

    Harris, Jay R

    2014-01-01

    Fifty years ago, radiation therapy (RT) was only used after mastectomy in patients with high-risk disease. The equipment, treatment planning, and treatment delivery were rudimentary compared to what is available today. In retrospect, the deleterious effects of the RT back then negated its benefits. The strategy of combining lesser surgery with RT (and adjuvant systemic therapy) has been successfully employed in breast-conserving therapy (BCT) and in avoiding axillary lymph node dissection in patients with 1 or 2 involved sentinel nodes. Local recurrence rates at 10 years following BCT are now similar to those following mastectomy. RT after breast-conserving surgery and after mastectomy has been demonstrated to not only decrease local-regional recurrence but also decrease distant metastases and improve long-term survival. The development of effective adjuvant systemic therapy has made RT not only more effective but also arguably more important. If systemic therapy is effective at addressing micro-metastatic disease, then obtaining local tumor control becomes even more important. Moderately hypofractionated RT (2.66 Gy per day) is just as safe and effective as conventional fractionation shortening BCT from 6 weeks to 3-4 weeks. Treatment is now given with multiple-energy linear accelerators, CT-based simulation, 3-dimensional beam modulation for much greater dose homogeneity, on-board imaging for greater daily accuracy, and various techniques to reduce cardiac dose. PMID:24857056

  4. Use of gamma radiation as a form of preservation of sweet potatoes. Quarterly progress report

    SciTech Connect

    Not Available

    1985-01-01

    This progress report covers: harvest and conditioning following harvest; effects of ..gamma.. radiation on the sweet potato weevil, organoleptic properties of sweet potatoes, protein content of same, and sweet potato quality (vitamins, color, texture, and carbohydrates). Evaluation of preliminary results indicate that changes should be made in irradiation procedures/conditions and analyses. (DLC)

  5. Cavity optomechanics with micromirrors: Progress towards the measurement of quantum radiation pressure noise and ponderomotive squeezing

    NASA Astrophysics Data System (ADS)

    Cripe, Jonathan; Singh, Robinjeet; Corbitt, Thomas; LIGO Collaboration

    2016-03-01

    Advanced LIGO is predicted to be limited by quantum noise at intermediate and high frequencies when it reaches design sensitivity. The quantum noise, including radiation pressure noise at intermediate frequencies, will need to be reduced in order to increase the sensitivity of future gravitational wave interferometers. We report recent progress towards measuring quantum radiation pressure noise in a cryogenic optomechanical cavity. The low noise microfabricated mechanical oscillator and cryogenic apparatus allow direct broadband thermal noise measurements which test thermal noise models and damping mechanisms. We also progress toward the measurement of the ponderomotive squeezing produced by the optomechanical cavity and the reduction of radiation pressure noise using squeezed light. These techniques may be applicable to an upgrade of Advanced LIGO or the next generation of gravitational wave detectors.

  6. Radiation physics, biophysics, and radiation biology. Progress report, December 1, 1993--November 30, 1994

    SciTech Connect

    Hall, E.J.; Zaider, M.

    1994-05-01

    Research at the Center for Radiological Research is a blend of physics, chemistry and biology and epitomizes the multidisciplinary approach towards understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. To an increasing extent, the focus of attention is on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights from the past year are briefly described.

  7. Radiologic response to radiation therapy concurrent with temozolomide for progressive simple dysembryoplastic neuroepithelial tumor.

    PubMed

    Morr, Simon; Qiu, Jingxin; Prasad, Dheerendra; Mechtler, Laszlo L; Fenstermaker, Robert A

    2016-07-01

    Dysembryoplastic neuroepithelial tumors (DNETs) are low-grade neuroglial tumors that are traditionally considered to be benign hamartoma-like mass lesions. Malignant transformation and disease progression have been reported in complex DNETs. We report a case of a simple DNET with disease progression following subtotal resection. A 34-year-old woman underwent craniotomy with subtotal resection of a large nonenhancing right temporal lobe and insular mass. Histopathological analysis revealed a simple DNET. Magnetic resonance imaging obtained 6 months after surgery demonstrated disease progression with no enhancement or change in signal characteristics. Following concurrent therapy with temozolomide and external beam radiation therapy, a significant radiologic response was observed. Progressive DNET with malignant transformation exhibits predominantly glial transformation and occurs predominantly in complex DNETs. The histological classification of DNETs into simple, complex, and nonspecific are reviewed. Contrast-enhancing regions are more frequently seen in complex tumors, with nonenhancing regions having fewer complex histologic features. Close clinical and radiographic follow-up is important in all cases of DNET. Following tumor progression, radiation therapy with concurrent and adjuvant temozolomide chemotherapy may be an effective treatment. PMID:27181792

  8. Radiation physics, biophysics, and radiation biology. Progress report, December 1, 1991--November 30, 1992

    SciTech Connect

    Hall, E.J.

    1992-05-01

    The following research programs from the Center for Radiological Research of Columbia University are described: Design and development of a new wall-less ultra miniature proportional counter for nanodosimetry; some recent measurements of ionization distributions for heavy ions at nanometer site sizes with a wall-less proportional counter; a calculation of exciton energies in periodic systems with helical symmetry: application to a hydrogen fluoride chain; electron energy-loss function in polynucleotide and the question of plasmon excitation; a non-parametric, microdosimetric-based approach to the evaluation of the biological effects of low doses of ionizing radiation; high-LET radiation risk assessment at medium doses; high-LET radiobiological effects: increased lesion severity or increased lesion proximity; photoneutrons generated by high energy medical linacs; the biological effectiveness of neutrons; implications for radiation protection; molecular characterization of oncogenes induced by neutrons; and the inverse dose-rate effect for oncogenic transformation by charged particles is LET dependent.

  9. The Early Whole-Blood Transcriptional Signature of Dengue Virus and Features Associated with Progression to Dengue Shock Syndrome in Vietnamese Children and Young Adults▿ † ‡

    PubMed Central

    Hoang, Long Truong; Lynn, David J.; Henn, Matt; Birren, Bruce W.; Lennon, Niall J.; Le, Phuong Thi; Duong, Kien Thi Hue; Nguyen, Tham Thi Hong; Mai, Lanh Ngoc; Farrar, Jeremy J.; Hibberd, Martin L.; Simmons, Cameron P.

    2010-01-01

    Dengue is a pantropic public health problem. In children, dengue shock syndrome (DSS) is the most common life-threatening complication. The ability to predict which patients may develop DSS may improve triage and treatment. To this end, we conducted a nested case-control comparison of the early host transcriptional features in 24 DSS patients and 56 sex-, age-, and virus serotype-matched uncomplicated (UC) dengue patients. In the first instance, we defined the “early dengue” profile. The transcriptional signature in acute rather than convalescent samples (≤72 h post-illness onset) was defined by an overabundance of interferon-inducible transcripts (31% of the 551 overabundant transcripts) and canonical gene ontology terms that included the following: response to virus, immune response, innate immune response, and inflammatory response. Pathway and network analyses identified STAT1, STAT2, STAT3, IRF7, IRF9, IRF1, CEBPB, and SP1 as key transcriptional factors mediating the early response. Strikingly, the only difference in the transcriptional signatures of early DSS and UC dengue cases was the greater abundance of several neutrophil-associated transcripts in patients who progressed to DSS, a finding supported by higher plasma concentrations of several canonical proteins associated with neutrophil degranulation (bactericidal/permeability-increasing protein [BPI], elastase 2 [ELA2], and defensin 1 alpha [DEF1A]). Elevated levels of neutrophil-associated transcripts were independent of the neutrophil count and also of the genotype of the infecting virus, as genome-length sequences of dengue virus serotype 1 (DENV-1) (n = 15) and DENV-2 (n = 3) sampled from DSS patients were phylogenetically indistinguishable from those sampled from uncomplicated dengue patients (32 DENV-1 and 9 DENV-2 sequences). Collectively, these data suggest a hitherto unrecognized association between neutrophil activation, pathogenesis, and the development of DSS and point to future

  10. Research progress in radiation detectors, pattern recognition programs, and radiation damage determination in DNA

    NASA Technical Reports Server (NTRS)

    Baily, N. A.

    1973-01-01

    The radiological implications of statistical variations in energy deposition by ionizing radiation were investigated in the conduct of the following experiments: (1) study of the production of secondary particles generated by the passage of the primary radiation through bone and muscle; (2) the study of the ratio of nonreparable to reparable damage in DNA as a function of different energy deposition patterns generated by X rays versus heavy fast charged particles; (3) the use of electronic radiography systems for direct fluoroscopic tomography and for the synthesis of multiple planes and; (4) the determination of the characteristics of systems response to split fields having different contrast levels, and of minimum detectable contrast levels between the halves under realistic clinical situations.

  11. UHECR: Signatures and models

    NASA Astrophysics Data System (ADS)

    Berezinsky, V.

    2013-06-01

    The signatures of Ultra High Energy (E ≳ 1 EeV) proton propagation through CMB radiation are pair-production dip and GZK cutoff. The visible characteristics of these two spectral features are ankle, which is intrinsic part of the dip, beginning of GZK cutoff in the differential spectrum and E1/2 in integral spectrum. Measured by HiRes and Telescope Array (TA) these characteristics agree with theoretical predictions. However, directly measured mass composition remains a puzzle. While HiRes and TA detectors observe the proton-dominated mass composition, the data of Auger detector strongly evidence for nuclei mass composition becoming progressively heavier at energy higher than 4 EeV and reaching Iron at energy about 35 EeV. The models based on the Auger and HiRes/TA data are considered independently and classified using the transition from galactic to extragalactic cosmic rays. The ankle cannot provide this transition. since data of all three detector at energy (1-3) EeV agree with pure proton composition (or at least not heavier than Helium). If produced in Galaxy these particles result in too high anisotropy. This argument excludes or strongly disfavours all ankle models with ankle energy Ea > 3 EeV. The calculation of elongation curves, Xmax(E), for different ankle models strengthens further this conclusion. Status of other models, the dip, mixed composition and Auger based models are discussed.

  12. Prognostic Utility of Cell Cycle Progression Score in Men With Prostate Cancer After Primary External Beam Radiation Therapy

    SciTech Connect

    Freedland, Stephen J.; Gerber, Leah; Reid, Julia; Welbourn, William; Tikishvili, Eliso; Park, Jimmy; Younus, Adib; Gutin, Alexander; Sangale, Zaina; Lanchbury, Jerry S.; Salama, Joseph K.; Stone, Steven

    2013-08-01

    Purpose: To evaluate the prognostic utility of the cell cycle progression (CCP) score, a RNA signature based on the average expression level of 31 CCP genes, for predicting biochemical recurrence (BCR) in men with prostate cancer treated with external beam radiation therapy (EBRT) as their primary curative therapy. Methods and Materials: The CCP score was derived retrospectively from diagnostic biopsy specimens of men diagnosed with prostate cancer from 1991 to 2006 (n=141). All patients were treated with definitive EBRT; approximately half of the cohort was African American. Outcome was time from EBRT to BCR using the Phoenix definition. Median follow-up for patients without BCR was 4.8 years. Association with outcome was evaluated by Cox proportional hazards survival analysis and likelihood ratio tests. Results: Of 141 patients, 19 (13%) had BCR. The median CCP score for patient samples was 0.12. In univariable analysis, CCP score significantly predicted BCR (P=.0017). The hazard ratio for BCR was 2.55 for 1-unit increase in CCP score (equivalent to a doubling of gene expression). In a multivariable analysis that included Gleason score, prostate-specific antigen, percent positive cores, and androgen deprivation therapy, the hazard ratio for CCP changed only marginally and remained significant (P=.034), indicating that CCP provides prognostic information that is not provided by standard clinical parameters. With 10-year censoring, the CCP score was associated with prostate cancer-specific mortality (P=.013). There was no evidence for interaction between CCP and any clinical variable, including ethnicity. Conclusions: Among men treated with EBRT, the CCP score significantly predicted outcome and provided greater prognostic information than was available with clinical parameters. If validated in a larger cohort, CCP score could identify high-risk men undergoing EBRT who may need more aggressive therapy.

  13. Signature control

    NASA Astrophysics Data System (ADS)

    Pyati, Vittal P.

    The reduction of vehicle radar signature is accomplished by means of vehicle shaping, the use of microwave frequencies-absorbent materials, and either passive or active cancellation techniques; such techniques are also useful in the reduction of propulsion system-associated IR emissions. In some anticipated scenarios, the objective is not signature-reduction but signature control, for deception, via decoy vehicles that mimic the signature characteristics of actual weapons systems. As the stealthiness of airframes and missiles increases, their propulsion systems' exhaust plumes assume a more important role in detection by an adversary.

  14. Dark progression reveals slow timescales for radiation damage between T = 180 and 240 K

    PubMed Central

    Warkentin, Matthew; Badeau, Ryan; Hopkins, Jesse; Thorne, Robert E.

    2011-01-01

    Can radiation damage to protein crystals be ‘outrun’ by collecting a structural data set before damage is manifested? Recent experiments using ultra-intense pulses from a free-electron laser show that the answer is yes. Here, evidence is presented that significant reductions in global damage at temperatures above 200 K may be possible using conventional X-ray sources and current or soon-to-be available detectors. Specifically, ‘dark progression’ (an increase in damage with time after the X-rays have been turned off) was observed at temperatures between 180 and 240 K and on timescales from 200 to 1200 s. This allowed estimation of the temperature-dependent timescale for damage. The rate of dark progression is consistent with an Arrhenius law with an activation energy of 14 kJ mol−1. This is comparable to the activation energy for the solvent-coupled diffusive damage processes responsible for the rapid increase in radiation sensitivity as crystals are warmed above the glass transition near 200 K. Analysis suggests that at T = 300 K data-collection times of the order of 1 s (and longer at lower temperatures) may allow significant reductions in global radiation damage, facilitating structure solution on crystals with liquid solvent. No dark progression was observed below T = 180 K, indicating that no important damage process is slowed through this timescale window in this temperature range. PMID:21904032

  15. In vivo mutagenicity and clastogenicity of ionizing radiation in nuclear medicine. Annual technical progress report, [1991

    SciTech Connect

    Kelsey, K.T.

    1991-12-31

    The overall goal of our research remains to investigate the mutagenic and clastogenic effects of exposure to low levels of ionizing radiation to human lymphocytes. Principally, we are studying hospital patients referred to a nuclear medicine department for diagnostic cardiac imaging and nuclear medicine technologies who administer radionuclides. Emphasis in the first year, as described in the first progress report, was on optimization of the hprt mutation assay, measurement of mutant frequencies in patients imaged with thallium-201, and measurement of mutant frequencies in controls. Emphasis in the second year has been on measurements of (1) chromosome aberrations in patients imaged with thallium-201, (2) mutant frequencies in patients imaged with technetium-99, (3) mutant frequencies in nuclear medicine technicians and physical therapists, (4) mutant frequencies in patients treated for Hodgkins disease with radiotherapy. The progress in these areas is described.

  16. Novel trophic niches drive variable progress towards ecological speciation within an adaptive radiation of pupfishes.

    PubMed

    Martin, Christopher H; Feinstein, Laura C

    2014-04-01

    Adaptive radiation is recognized by a rapid burst of phenotypic, ecological and species diversification. However, it is unknown whether different species within an adaptive radiation evolve reproductive isolation at different rates. We compared patterns of genetic differentiation between nascent species within an adaptive radiation of Cyprinodon pupfishes using genotyping by sequencing. Similar to classic adaptive radiations, this clade exhibits rapid morphological diversification rates and two species are novel trophic specialists, a scale-eater and hard-shelled prey specialist (durophage), yet the radiation is <10 000 years old. Both specialists and an abundant generalist species all coexist in the benthic zone of lakes on San Salvador Island, Bahamas. Based on 13 912 single-nucleotide polymorphisms (SNPs), we found consistent differences in genetic differentiation between each specialist species and the generalist across seven lakes. The scale-eater showed the greatest genetic differentiation and clustered by species across lakes, whereas durophage populations often clustered with sympatric generalist populations, consistent with parallel speciation across lakes. However, we found strong evidence of admixture between durophage populations in different lakes, supporting a single origin of this species and genome-wide introgression with sympatric generalist populations. We conclude that the scale-eater is further along the speciation-with-gene-flow continuum than the durophage and suggest that different adaptive landscapes underlying these two niche environments drive variable progress towards speciation within the same habitat. Our previous measurements of fitness surfaces in these lakes support this conclusion: the scale-eating fitness peak may be more distant than the durophage peak on the complex adaptive landscape driving adaptive radiation. PMID:24393262

  17. Radiation promotes malignant progression of glioma cells through HIF-1alpha stabilization.

    PubMed

    Kim, Young-Heon; Yoo, Ki-Chun; Cui, Yan-Hong; Uddin, Nizam; Lim, Eun-Jung; Kim, Min-Jung; Nam, Seon-Young; Kim, In-Gyu; Suh, Yongjoon; Lee, Su-Jae

    2014-11-01

    Given its contribution to malignant phenotypes of cancer, tumor hypoxia has been considered as a potential therapeutic problem. In the stressful microenvironment condition, hypoxia inducible factor 1 (HIF1) is well known to mediate the transcriptional adaptation of cells to hypoxia and acts as a central player for the process of hypoxia-driven malignant cancer progression. Here, we found that irradiation causes the HIF1α protein to stabilize, even in normoxia condition through activation of p38 MAPK, thereby promoting angiogenesis in tumor microenvironment and infiltrative property of glioma cells. Notably, irradiation reduced hydroxylation of HIF1α through destabilization of prolyl hydroxylases (PHD)-2. Moreover, radiation also decreased the half-life of protein von Hippel-Lindau (pVHL), which is a specific E3 ligase for HIF1α. Of note, inhibition of p38 MAPK attenuated radiation-induced stabilization of HIF1α through destabilization of PHD-2 and pVHL. In agreement with these results, targeting of either p38 MAPK, HIF1α, pVHL or PHD-2 effectively mitigated the radiation-induced tube formation of human brain-derived micro-vessel endothelial cells (HB-MEC) and infiltration of glioma cells. Taken together, our findings suggest that targeting HIF1α in combination with ionizing radiation might increase the efficacy of radiotherapy for glioma treatment. PMID:25109450

  18. Acoustic backscattering and radiation force on a rigid elliptical cylinder in plane progressive waves.

    PubMed

    Mitri, F G

    2016-03-01

    This work proposes a formal analytical theory using the partial-wave series expansion (PWSE) method in cylindrical coordinates, to calculate the acoustic backscattering form function as well as the radiation force-per-length on an infinitely long elliptical (non-circular) cylinder in plane progressive waves. The major (or minor) semi-axis of the ellipse coincides with the direction of the incident waves. The scattering coefficients for the rigid elliptical cylinder are determined by imposing the Neumann boundary condition for an immovable surface and solving a resulting system of linear equations by matrix inversion. The present method, which utilizes standard cylindrical (Bessel and Hankel) wave functions, presents an advantage over the solution for the scattering that is ordinarily expressed in a basis of elliptical Mathieu functions (which are generally non-orthogonal). Furthermore, an integral equation showing the direct connection of the radiation force function with the square of the scattering form function in the far-field from the scatterer (applicable for plane waves only), is noted and discussed. An important application of this integral equation is the adequate evaluation of the radiation force function from a bistatic measurement (i.e., in the polar plane) of the far-field scattering from any 2D object of arbitrary shape. Numerical predictions are evaluated for the acoustic backscattering form function and the radiation force function, which is the radiation force per unit length, per characteristic energy density, and per unit cross-sectional surface of the ellipse, with particular emphasis on the aspect ratio a/b, where a and b are the semi-axes, as well as the dimensionless size parameter kb, without the restriction to a particular range of frequencies. The results are particularly relevant in acoustic levitation, acousto-fluidics and particle dynamics applications. PMID:26726146

  19. Human genetic marker for resistance to radiations and chemicals. 1998 annual progress report

    SciTech Connect

    Lieberman, H.B.

    1998-06-01

    'The broad objective of the project is to understand the molecular basis for the response of cells to radiations and chemicals, with the pragmatic goal of being able to identify human subpopulations that are exceptionally sensitive to DNA damaging agents. The project focuses on HRAD9, a human orthologue of the fission yeast Schizosaccharomyces pombe gene rad9. S. pombe rad9::ura4+ mutant cells are highly sensitive to ionizing radiation, UV and many chemicals, such as the DNA synthesis inhibitor hydroxyurea. They also lack the ability to delay cycling transiently in S phase or in G2 following a block in DNA replication or after incurring DNA damage, respectively -i.e., they lack checkpoint controls. The attempt by mutant cells to progress through mitosis in the absence of fully intact DNA accounts at least in part for their sensitivity to DNA damaging agents. Cells bearing rad9::ura4+ also aberrantly regulate UVDE, an enzyme that participates in a secondary DNA excision repair pathway. The key role played by S. pombe rad9 in promoting resistance to chemicals and radiations suggests that the evolutionarily conserved human cognate also has important functions in mammals. The first set of aims in this proposal centers on characterizing the structure and expression of HRAD9, to assess structure/function relationships and potentially link protein activity to a specific tissue. The next set of aims focuses on determining the role of HRAD9 in radio/chemoresponsiveness and cancer.'

  20. Progressive behavioral changes in rats after exposure to low levels of ionizing radiation in utero

    SciTech Connect

    Norton, S.; Kimler, B.F.; Mullenix, P.J. )

    1991-03-01

    The deleterious effects of ionizing radiation on the developing brain may be not only prolonged but progressive. Fetuses were exposed to 0.75 Gy of ionizing radiation on gestational day 15 through whole body exposure of the pregnant rat. Three behavioral tests (gait analysis, continuous corridor activity and photographic analysis of sequences of behavioral acts) were performed at 1 and 3 months, postnatally. Body weight and thickness of the cerebral cortex of irradiated rats were 10-15 percent below controls throughout the period of study. Behavior in all tests was more affected at 3 months than at 1 month of age. Gait of control rats, as measured by the angle of advanced of hind feet, widened about 20 percent for males and 40 percent for females from 1 to 3 months, as expected, while, in irradiated rats, the angle widened only about 10 percent. Continuous corridor activity increased less than 10 percent in controls and about 35 percent in irradiated rats over the same period. In photographic analysis of behavior, controls increased their time spent standing by about 50 percent in males and 20 percent in females from 1 to 3 months of age. Irradiated males increased time standing only about 10 percent and irradiated females decreased about 30 percent over the same period. The data obtained in these experiments support other evidence that some behavioral alterations from perinatal exposure to radiation become more marked with maturation.

  1. Third Radiation Transfer Model Intercomparison (RAMI) exercise: Documenting progress in canopy reflectance models

    NASA Astrophysics Data System (ADS)

    Widlowski, J.-L.; Taberner, M.; Pinty, B.; Bruniquel-Pinel, V.; Disney, M.; Fernandes, R.; Gastellu-Etchegorry, J.-P.; Gobron, N.; Kuusk, A.; Lavergne, T.; Leblanc, S.; Lewis, P. E.; Martin, E.; Mõttus, M.; North, P. R. J.; Qin, W.; Robustelli, M.; Rochdi, N.; Ruiloba, R.; Soler, C.; Thompson, R.; Verhoef, W.; Verstraete, M. M.; Xie, D.

    2007-05-01

    The Radiation Transfer Model Intercomparison (RAMI) initiative benchmarks canopy reflectance models under well-controlled experimental conditions. Launched for the first time in 1999, this triennial community exercise encourages the systematic evaluation of canopy reflectance models on a voluntary basis. The first phase of RAMI focused on documenting the spread among radiative transfer (RT) simulations over a small set of primarily 1-D canopies. The second phase expanded the scope to include structurally complex 3-D plant architectures with and without background topography. Here sometimes significant discrepancies were noted which effectively prevented the definition of a reliable "surrogate truth," over heterogeneous vegetation canopies, against which other RT models could then be compared. The present paper documents the outcome of the third phase of RAMI, highlighting both the significant progress that has been made in terms of model agreement since RAMI-2 and the capability of/need for RT models to accurately reproduce local estimates of radiative quantities under conditions that are reminiscent of in situ measurements. Our assessment of the self-consistency and the relative and absolute performance of 3-D Monte Carlo models in RAMI-3 supports their usage in the generation of a "surrogate truth" for all RAMI test cases. This development then leads (1) to the presentation of the "RAMI Online Model Checker" (ROMC), an open-access web-based interface to evaluate RT models automatically, and (2) to a reassessment of the role, scope, and opportunities of the RAMI project in the future.

  2. Signature of the Schwinger pair creation rate via radiation generated in graphene by a strong electric current

    SciTech Connect

    Lewkowicz, M.; Kao, H. C.; Rosenstein, B.

    2011-07-15

    Electron-hole pairs are copiously created by an applied electric field near the Dirac point in graphene or similar two-dimensional electronic systems. It was shown recently that for sufficiently large electric fields E and ballistic times the I-V characteristics become strongly nonlinear due to Schwinger's pair creation rate, proportional to E{sup 3/2}. Since there is no energy gap the radiation from the pairs' annihilation is enhanced. The spectrum of radiation is calculated and exhibits a maximum at {omega}={radical}(eEv{sub g}/({h_bar}/2{pi})). The angular and polarization dependence of the emitted photons with respect to the graphene sheet is quite distinctive. For very large currents the recombination rate becomes so large that it leads to the second Ohmic regime due to radiation friction.

  3. Directed evolution and in silico analysis of reaction centre proteins reveal molecular signatures of photosynthesis adaptation to radiation pressure.

    PubMed

    Rea, Giuseppina; Lambreva, Maya; Polticelli, Fabio; Bertalan, Ivo; Antonacci, Amina; Pastorelli, Sandro; Damasso, Mario; Johanningmeier, Udo; Giardi, Maria Teresa

    2011-01-01

    Evolutionary mechanisms adopted by the photosynthetic apparatus to modifications in the Earth's atmosphere on a geological time-scale remain a focus of intense research. The photosynthetic machinery has had to cope with continuously changing environmental conditions and particularly with the complex ionizing radiation emitted by solar flares. The photosynthetic D1 protein, being the site of electron tunneling-mediated charge separation and solar energy transduction, is a hot spot for the generation of radiation-induced radical injuries. We explored the possibility to produce D1 variants tolerant to ionizing radiation in Chlamydomonas reinhardtii and clarified the effect of radiation-induced oxidative damage on the photosynthetic proteins evolution. In vitro directed evolution strategies targeted at the D1 protein were adopted to create libraries of chlamydomonas random mutants, subsequently selected by exposures to radical-generating proton or neutron sources. The common trend observed in the D1 aminoacidic substitutions was the replacement of less polar by more polar amino acids. The applied selection pressure forced replacement of residues more sensitive to oxidative damage with less sensitive ones, suggesting that ionizing radiation may have been one of the driving forces in the evolution of the eukaryotic photosynthetic apparatus. A set of the identified aminoacidic substitutions, close to the secondary plastoquinone binding niche and oxygen evolving complex, were introduced by site-directed mutagenesis in un-transformed strains, and their sensitivity to free radicals attack analyzed. Mutants displayed reduced electron transport efficiency in physiological conditions, and increased photosynthetic performance stability and oxygen evolution capacity in stressful high-light conditions. Finally, comparative in silico analyses of D1 aminoacidic sequences of organisms differently located in the evolution chain, revealed a higher ratio of residues more sensitive to

  4. Directed Evolution and In Silico Analysis of Reaction Centre Proteins Reveal Molecular Signatures of Photosynthesis Adaptation to Radiation Pressure

    PubMed Central

    Rea, Giuseppina; Lambreva, Maya; Polticelli, Fabio; Bertalan, Ivo; Antonacci, Amina; Pastorelli, Sandro; Damasso, Mario; Johanningmeier, Udo; Giardi, Maria Teresa

    2011-01-01

    Evolutionary mechanisms adopted by the photosynthetic apparatus to modifications in the Earth's atmosphere on a geological time-scale remain a focus of intense research. The photosynthetic machinery has had to cope with continuously changing environmental conditions and particularly with the complex ionizing radiation emitted by solar flares. The photosynthetic D1 protein, being the site of electron tunneling-mediated charge separation and solar energy transduction, is a hot spot for the generation of radiation-induced radical injuries. We explored the possibility to produce D1 variants tolerant to ionizing radiation in Chlamydomonas reinhardtii and clarified the effect of radiation-induced oxidative damage on the photosynthetic proteins evolution. In vitro directed evolution strategies targeted at the D1 protein were adopted to create libraries of chlamydomonas random mutants, subsequently selected by exposures to radical-generating proton or neutron sources. The common trend observed in the D1 aminoacidic substitutions was the replacement of less polar by more polar amino acids. The applied selection pressure forced replacement of residues more sensitive to oxidative damage with less sensitive ones, suggesting that ionizing radiation may have been one of the driving forces in the evolution of the eukaryotic photosynthetic apparatus. A set of the identified aminoacidic substitutions, close to the secondary plastoquinone binding niche and oxygen evolving complex, were introduced by site-directed mutagenesis in un-transformed strains, and their sensitivity to free radicals attack analyzed. Mutants displayed reduced electron transport efficiency in physiological conditions, and increased photosynthetic performance stability and oxygen evolution capacity in stressful high-light conditions. Finally, comparative in silico analyses of D1 aminoacidic sequences of organisms differently located in the evolution chain, revealed a higher ratio of residues more sensitive to

  5. Serum Proteome Signature of Radiation Response: Upregulation of Inflammation-Related Factors and Downregulation of Apolipoproteins and Coagulation Factors in Cancer Patients Treated With Radiation Therapy—A Pilot Study

    SciTech Connect

    Widlak, Piotr; Jelonek, Karol; Wojakowska, Anna; Pietrowska, Monika; Polanska, Joanna; Marczak, Łukasz; Miszczyk, Leszek; Składowski, Krzysztof

    2015-08-01

    Purpose: Ionizing radiation affects the proteome of irradiated cells and tissue, yet data concerning changes induced during radiation therapy (RT) in human blood are fragmentary and inconclusive. We aimed to identify features of serum proteome and associated processes involved in response to partial body irradiation during cancer treatment. Methods and Materials: Twenty patients with head and neck squamous cell cancer (HNSCC) and 20 patients with prostate cancer received definitive intensity modulated RT. Blood samples were collected before RT, just after RT, and 1 month after the end of RT. Complete serum proteome was analyzed in individual samples, using a shotgun liquid chromatography-tandem mass spectrometry approach which allowed identification of approximately 450 proteins. Approximately 100 unique proteins were quantified in all samples after exclusion of immunoglobulins, and statistical significance of differences among consecutive samples was assessed. Processes associated with quantified proteins and their functional interactions were predicted using gene ontology tools. Results: RT-induced changes were marked in the HNSCC patient group: 22 upregulated and 33 downregulated proteins were detected in post-RT sera. Most of the changes reversed during follow-up, yet levels of some proteins remained affected 1 month after the end of RT. RT-upregulated proteins were associated with acute phase, inflammatory response, and complement activation. RT-downregulated proteins were associated with transport and metabolism of lipids (plasma apolipoproteins) and blood coagulation. RT-induced changes were much weaker in prostate cancer patients, which corresponded to differences in acute radiation toxicity observed in both groups. Nevertheless, general patterns of RT-induced sera proteome changes were similar in both of the groups of cancer patients. Conclusions: In this pilot study, we proposed to identify a molecular signature of radiation response, based on specific

  6. Solar radiation signature manifested on the spatial patterns of modeled soil moisture, vegetation, and topography using an ecohydro-geomorphic landscape evolution model

    NASA Astrophysics Data System (ADS)

    Yetemen, O.; Flores Cervantes, J. H.; Istanbulluoglu, E.; Vivoni, E. R.

    2013-12-01

    The role of solar radiation on ecohydrologic fluxes, vegetation dynamics, species composition, and landscape morphology have long been documented in field studies. However a numerical model framework to integrate a range of ecohydrologic and geomorphic processes to explore the integrated ecohydro-geomorphic landscape response have been missing. In this study, our aim is to realistically represent flood generation and solar-radiation-driven echydrologic dynamics in a landscape evolution model (LEM) to investigate how ecohydrologic differences caused by differential irradiance on opposing hillslopes manifest themselves on the organization of modeled topography, soil moisture and plant biomass. We use the CHILD LEM equipped with a spatially-distributed solar-radiation component, leading to spatial patterns of soil moisture; a vegetation dynamics component that explicitly tracks above- and below-ground biomass; and a runoff component that allows for runoff-runon processes along the landscape flow paths. Ecohydrological component has been verified using a detailed data gathered from Sevilleta National Wildlife Refuge in central New Mexico, and Walnut Gulch Experimental Watershed in southern Arizona. LEM scenarios were designed to compare the outcomes of spatially distributed versus spatially uniform solar radiation forced with a constant climate and variable uplift. Modeled spatial patterns of soil moisture confirm empirical observations at the landscape scale and other hydrologic modeling studies. The spatial variability in soil moisture is controlled by aspect prior to the wet season (North American Monsoon, NAM), and by the hydraulic connectivity of the flow network during NAM. Aspect and network connectivity signatures are also manifested on plant biomass with typically denser vegetation cover on north-facing slopes than south facing slopes. Over the long-term, CHILD gives slightly steeper and less dissected north-facing slopes more dissected south facing slopes and

  7. Recent progress and tests of radiation resistant impregnation materials for Nb{sub 3}Sn coils

    SciTech Connect

    Bossert, R.; Krave, S.; Ambrosio, G.; Andreev, N.; Chlachidze, G.; Nobrega, A.; Novitski, I.; Yu, M.; Zlobin, A. V.

    2014-01-27

    Fermilab is collaborating with Lawrence Berkeley National Laboratory (LBNL) and Brookhaven National Laboratory (BNL) (US-LARP collaboration) to develop a large-aperture Nb{sub 3}Sn superconducting quadrupole for the Large Hadron Collider (LHC) luminosity upgrade. An important component of this work is the development of materials that are sufficiently radiation resistant for use in critical areas of the upgrade. This paper describes recent progress in characterization of materials, including the baseline CTD101K epoxy, cyanate ester blends, and Matrimid 5292, a bismaleimide-based system. Structural properties of “ten stacks” of cable impregnated with these materials are tested at room and cryogenic temperatures and compared to the baseline CT-101K. Experience with potting 1 and 2 meter long coils with Matrimid 5292 are described. Test results of a single 1-m coil impregnated with Matrimid 5292 are reported and compared to similar coils impregnated with the traditional epoxy.

  8. Recent progress and tests of radiation resistant impregnation materials for Nb3Sn coils

    NASA Astrophysics Data System (ADS)

    Bossert, R.; Krave, S.; Ambrosio, G.; Andreev, N.; Chlachidze, G.; Nobrega, A.; Novitski, I.; Yu, M.; Zlobin, A. V.

    2014-01-01

    Fermilab is collaborating with Lawrence Berkeley National Laboratory (LBNL) and Brookhaven National Laboratory (BNL) (US-LARP collaboration) to develop a large-aperture Nb3Sn superconducting quadrupole for the Large Hadron Collider (LHC) luminosity upgrade. An important component of this work is the development of materials that are sufficiently radiation resistant for use in critical areas of the upgrade. This paper describes recent progress in characterization of materials, including the baseline CTD101K epoxy, cyanate ester blends, and Matrimid 5292, a bismaleimide-based system. Structural properties of "ten stacks" of cable impregnated with these materials are tested at room and cryogenic temperatures and compared to the baseline CT-101K. Experience with potting 1 and 2 meter long coils with Matrimid 5292 are described. Test results of a single 1-m coil impregnated with Matrimid 5292 are reported and compared to similar coils impregnated with the traditional epoxy.

  9. Progress in iron transmission measurements relevant to the solar convection/radiation boundary

    NASA Astrophysics Data System (ADS)

    Bailey, James; Rochau, G. A.; Hansen, S. B.; Lake, P. W.; Nash, T. J.; Nielsen, D. S.; Thomas, R. D.; Iglesias, C. A.; Abdallah, J.; Sherrill, M. E.; Macfarlane, J. J.; Golovkin, I.; Mancini, R. C.; Blancard, C.; Cosse, Ph.; Faussurier, G.; Gilleron, F.; Pain, J. C.; Pradhan, A. K.; Nahar, S. N.; Pinsonneault, M.

    2010-11-01

    Iron plasma opacity influences the internal structure of the sun. However, opacity models have never been experimentally tested at stellar interior conditions. Initial experiments at the Sandia Z facility reached temperatures high enough to investigate the iron charge states that exist near the convection/radiation zone (CZ) boundary. In these experiments the density was an order of magnitude lower than at the CZ boundary, preventing studies of important effects such as line broadening. New experiments have reached higher densities and temperatures. Progress to solidify these results and use them to examine opacity models will be described.++Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94AL85000.

  10. Progress In Iron Transmission Measurements Relevant to the Solar Convection/Radiation Boundary

    NASA Astrophysics Data System (ADS)

    Bailey, Jim; Nagayama, T.; Loisel, G.; Rochau, G. A; Blancard, C.; Colgan, J.; Cosse, Ph; Faussurier, G.; Fontes, Christopher J; Golovkin, I.; Hansen, S. B; Iglesias, C. A; Kilcrease, D. P; MacFarlane, Joseph J.; Mancini, Roberto; Nahar, S. N; Nash, T. J; Orban, Chris; Pinsonneault, Marc H.; Pradhan, Anil Kumar; Sherrill, M.; Wilson, B. G

    2014-06-01

    Iron plasma opacity influences the internal structure of the sun. However, opacity models have never been experimentally tested at stellar interior conditions. Recent iron opacity experiments at the Sandia Z facility reached 195 eV temperatures, nearly the same as the solar convection/radiation zone boundary (CZB), at electron densities that are roughly ½ the solar CZB value. Progress to solidify these results and use them to examine the physical underpinnings of opacity models will be described. We will also discuss impact of the results on the Rosseland mean opacities important for stellar physics.++Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94AL85000.

  11. Locoregional Tumor Progression After Radiation Therapy Influences Overall Survival in Pediatric Patients With Neuroblastoma

    SciTech Connect

    Pai Panandiker, Atmaram S.; McGregor, Lisa; Krasin, Matthew J.; Wu Shengjie; Xiong Xiaoping; Merchant, Thomas E.

    2010-03-15

    Purpose: There is renewed attention to primary site irradiation and local control for patients with high-risk neuroblastoma (NB). We conducted a retrospective review to identify factors that might predict for locoregional tumor control and its impact on overall survival. Methods and Materials: Between July 2000 through August 2006, a total of 44 pediatric patients with NB received radiation therapy (RT) with curative intent using computed tomography (CT)-based treatment planning. The median age was 3.4 years and the median cumulative dose was 23.4 Gy. Overall survival and locoregional tumor control were measured from the start of RT to the date of death or event as determined by CT/magnetic resonance imaging/meta-iodobenzylguanidine. The influence of age at irradiation, gender, race, cumulative radiation dose, International Neuroblastoma Staging System stage, treatment protocol and resection status was determined with respect to locoregional tumor control. Results: With a median follow-up of 34 months +- 21 months, locoregional tumor progression was observed in 11 (25%) and was evenly divided between primary site and adjacent nodal/visceral site failure. The influence of locoregional control reached borderline statistical significance (p = 0.06). Age (p = 0.5), dose (p = 0.6), resection status (p = 0.7), and International Neuroblastoma Staging System stage (p = 0.08) did not influence overall survival. Conclusions: Overall survival in high-risk neuroblastoma is influenced by locoregional tumor control. Despite CT-based planning, progression in adjacent nodal/visceral sites appears to be common; this requires further investigation regarding target volume definitions, dose, and the effects of systemic therapy.

  12. Progress in Z-Pinch driven dynamic-hohlraums for high-temperature radiation-flow and ICF experiments at Sandia National Laboratories.

    SciTech Connect

    Bailey, James E.; Haines, Malcolm G.; Chandler, Gordon Andrew; Bliss, David Emery; Olson, Richard Edward; Sanford, Thomas W. L.; Olson, Craig Lee; Nash, Thomas J.; Ruiz, Carlos L.; Matzen, Maurice Keith; Idzorek, George C.; Stygar, William A.; Apruzese, John P.; Cuneo, Michael Edward; Cooper, Gary Wayne; Chittenden, Jeremy Paul; Chrien, Robert E.; Slutz, Stephen A.; Mock, Raymond Cecil; Leeper, Ramon Joe; Sarkisov, Gennady Sergeevich; Peterson, Darrell L.; Lemke, Raymond William; Mehlhorn, Thomas Alan; Roderick, Norman Frederick; Watt, Robert G.

    2004-06-01

    Progress in understanding the physics of dynamic-hohlraums is reviewed for a system capable of generating 13 TW of axial radiation for high temperature (>200 eV) radiation-flow experiments and ICF capsule implosions.

  13. Mechanisms of interaction of radiation with matter. Progress report, July 1, 1991--August 31, 1992

    SciTech Connect

    Geacintov, N.E.; Pope, M.

    1992-08-31

    This project is concerned with studies of biological activity-structure relationships in which the mechanisms of interaction of ionizing radiation and benzopyrene (PB) compounds with DNA are being investigated and compared. Emphasis is focused on effects of DNA conformation on its mechanisms of interaction with ionizing radiation, on the influence of structure and stereochemistry of BP metabolites on mechanisms of DNA damage, and on influence of DNA conformation on interactions between BP metabolites and DNA molecules, and the structures of the complexes and adducts which are formed. One basic theme of this project is the use of photoexcited states of BP and nucleic acids as probes of these interactions. In part I of this report, recent progress on elucidating the structures of selected BP-oligonucleotide model adducts by high resolution NMR and gel electrophoresis techniques is summarized. It is shown that the stereochemical properties of benzo[a]pyrene diol epoxide-DNA adducts play a crucial role in determining their interactions with certain exonucleases. These results provide useful models for deriving a better understanding of differences biological activities of BP compounds and the relationships between mutagenicities and the structure properties of BP-DNA adducts. In Part II of this report, a new time-resolved method based on picosecond laser pulse techniques for elucidating the electronic levels involved in electron photoemission and electron transfer in BP and nucleic acid solids is described.

  14. A radiative analysis of angular signatures and oblique radiance retrievals over the polar regions from the multi-angle imaging spectroradiometer

    NASA Astrophysics Data System (ADS)

    Wilson, Michael Jason

    not be completely resolved for bright surfaces. The Mishchenko Radiative Transfer Solution for Flat Layers outperformed both the Lambertian and Hapke models, but overpredicted forward scattering and underpredicted backscatter. The use of a Koch Fractal model decreased forward scattering, but still failed to catch the increase in backscatter noted in MISR retrievals. (4) This dissertation develops the Angular Signature Cloud Mask (ASCM) into a standard MISR product and evaluates the performance through global and regional analyses. The Band-Differenced Angular Signature (BDAS) uses the oblique cameras from MISR in the direction of forward-scattered radiation, for which low clouds over ice are a strength. The Angular Signature Cloud Mask (ASCM) applies thresholds to the BDAS to determine whether clouds are present for any given pixel. The Support Vector Machine (SVM) is used as a truth dataset for comparison to the ASCM. Agreement rates between the SVM and ASCM were 80.2% over water, 76.0% over land, and 90.0% over ice-covered surfaces.

  15. Radiation-induced formation of 2',3'-dideoxyribonucleosides in DNA: a potential signature of low-energy electrons.

    PubMed

    Madugundu, Guru S; Park, Yeunsoo; Sanche, Léon; Wagner, J Richard

    2012-10-24

    We have identified a series of modifications of the 2'-deoxyribose moiety of DNA arising from the exposure of isolated and cellular DNA to ionizing radiation. The modifications consist of 2',3'-dideoxyribonucleoside derivatives of T, C, A, and G, as identified by enzymatic digestion and LC-MS/MS. Under dry conditions, the yield of these products was 6- to 44-fold lower than the yield of 8-oxo-7,8-dihydroguanine. We propose that 2',3'-dideoxyribonucleosides are generated from the reaction of low-energy electrons with DNA, leading to cleavage of the C3'-O bond and formation of the corresponding C3'-deoxyribose radical. PMID:23057636

  16. Searching the Inclusive Lepton + Photon + Missing E(T) + b-quark Signature for Radiative Top Quark Decay and Non-Standard-Model Processes

    SciTech Connect

    Aaltonen, T.; Adelman, Jahred A.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, Dante E.; Anastassov, A.; Annovi, Alberto; Antos, Jaroslav; Apollinari, G.; Apresyan, A.; /Purdue U. /Waseda U.

    2009-06-01

    In a search for new phenomena in a signature suppressed in the standard model of elementary particles (SM), we compare the inclusive production of events containing a lepton ({ell}), a photon ({gamma}), significant transverse momentum imbalance (E{sub T}), and a jet identified as containing a b-quark, to SM predictions. The search uses data produced in proton-antiproton collisions at {radical}s = 1.96 TeV corresponding to 1.9 fb{sup -1} of integrated luminosity taken with the CDF detector at the Fermilab Tevatron. We find 28 {ell}{gamma}bE{sub T} events versus an expectation of 31.0{sub -3.5}{sup +4.1} events. If we further require events to contain at least three jets and large total transverse energy, simulations predict that the largest SM source is top-quark pair production with an additional radiated photon, t{bar t} + {gamma}. In the data we observe 16 t{bar t}{gamma} candidate events versus an expectation from non-top-quark SM sources of 11.2{sub -2.1}{sup +2.3}. Assuming the difference between the observed number and the predicted non-top-quark total is due to SM top quark production, we estimate the t{bar t} cross section to be 0.15 {+-} 0.08 pb.

  17. Signatures of asymmetry in neutron spectra and images predicted by three-dimensional radiation hydrodynamics simulations of indirect drive implosions

    NASA Astrophysics Data System (ADS)

    Chittenden, J. P.; Appelbe, B. D.; Manke, F.; McGlinchey, K.; Niasse, N. P. L.

    2016-05-01

    We present the results of 3D simulations of indirect drive inertial confinement fusion capsules driven by the "high-foot" radiation pulse on the National Ignition Facility. The results are post-processed using a semi-deterministic ray tracing model to generate synthetic deuterium-tritium (DT) and deuterium-deuterium (DD) neutron spectra as well as primary and down scattered neutron images. Results with low-mode asymmetries are used to estimate the magnitude of anisotropy in the neutron spectra shift, width, and shape. Comparisons of primary and down scattered images highlight the lack of alignment between the neutron sources, scatter sites, and detector plane, which limits the ability to infer the ρr of the fuel from a down scattered ratio. Further calculations use high bandwidth multi-mode perturbations to induce multiple short scale length flows in the hotspot. The results indicate that the effect of fluid velocity is to produce a DT neutron spectrum with an apparently higher temperature than that inferred from the DD spectrum and which is also higher than the temperature implied by the DT to DD yield ratio.

  18. Assessment of WRF microphysics schemes to simulate extreme precipitation events from the perspective of GMI radiative signatures

    NASA Astrophysics Data System (ADS)

    Choi, Y.; Shin, D. B.; Joh, M.

    2015-12-01

    Numerical simulations of precipitation depend to a large degree on the assumed cloud microphysics schemes representing the formation, growth and fallout of cloud droplets and ice crystals. Recent studies show that assumed cloud microphysics play a major role not only in forecasting precipitation, especially in cases of extreme precipitation events, but also in the quality of the passive microwave rainfall estimation. Evaluations of the various Weather Research Forecasting (WRF) model microphysics schemes in this study are based on a method that was originally developed to construct the a-priori databases of precipitation profiles and associated brightness temperatures (TBs) for precipitation retrievals. This methodology generates three-dimensional (3D) precipitation fields by matching the GPM dual frequency radar (DPR) reflectivity profiles with those calculated from cloud resolving model (CRM)-derived hydrometeor profiles. The method eventually provides 3D simulated precipitation fields over the DPR scan swaths. That is, atmospheric and hydrometeor profiles can be generated at each DPR pixel based on CRM and DPR reflectivity profiles. The generated raining systems over DPR observation fields can be applied to any radiometers that are unaccompanied with a radar for microwave radiative calculation with consideration of each sensor's channel and field of view. Assessment of the WRF model microphysics schemes for several typhoon cases in terms of emission and scattering signals of GMI will be discussed.

  19. Outgoing Longwave Radiation (OLR) as signatures of pre-seismic activities before Nepal 2015 Earthquakes using onboard NOAA satellite data

    NASA Astrophysics Data System (ADS)

    Chakraborty, Suman; Chakrabarti, Sandip Kumar; Sasmal, Sudipta

    2016-07-01

    Earthquake preparation processes start almost a month before its actual occurrence. There are various tools in detecting such processes among which Outgoing Longwave Radiation (OLR) measurements is a significant one. We studied these signals before the devastating Nepal earthquake that occurred on 12 May, 2015 at 12:50 pm local time (07:05 UTC) with a Richter scale magnitude of M = 7.3 and depth 10 km (6.21 miles) at southeast of Kodari. To study the effects of seismic activities on OLR, we used the data archived by the National Environmental Satellite Data and Information Service (NESDIS) of National Oceanic and Atmospheric Administration (NOAA) onto two degree grids for a period of more than 27 years. For the period 2005 till date, data from NOAA18 satellite is used. The data has been chosen with a temporal coverage from 8th May to 17th May, 2015 and a spatial coverage from 20 ^{o}N to 36 ^{o}N latitudes, 78 ^{o}E to 94 ^{o}E longitudes. We followed the method of 'Eddy field calculation mean' to find anomalies in daily OLR curves. We found singularities in Eddy field around the earthquake epicentre three days prior to the earthquake day and its disappearance after the event. Such intensification of Eddy field and its fading away after the shock event can be due to the large amount of energy released before the earthquake.

  20. First Generation Gene Expression Signature for Early Prediction of Late Occurring Hematological Acute Radiation Syndrome in Baboons.

    PubMed

    Port, M; Herodin, F; Valente, M; Drouet, M; Lamkowski, A; Majewski, M; Abend, M

    2016-07-01

    We implemented a two-stage study to predict late occurring hematologic acute radiation syndrome (HARS) in a baboon model based on gene expression changes measured in peripheral blood within the first two days after irradiation. Eighteen baboons were irradiated to simulate different patterns of partial-body and total-body exposure, which corresponded to an equivalent dose of 2.5 or 5 Gy. According to changes in blood cell counts the surviving baboons (n = 17) exhibited mild (H1-2, n = 4) or more severe (H2-3, n = 13) HARS. Blood samples taken before irradiation served as unexposed control (H0, n = 17). For stage I of this study, a whole genome screen (mRNA microarrays) was performed using a portion of the samples (H0, n = 5; H1-2, n = 4; H2-3, n = 5). For stage II, using the remaining samples and the more sensitive methodology, qRT-PCR, validation was performed on candidate genes that were differentially up- or down-regulated during the first two days after irradiation. Differential gene expression was defined as significant (P < 0.05) and greater than or equal to a twofold difference above a H0 classification. From approximately 20,000 genes, on average 46% appeared to be expressed. On day 1 postirradiation for H2-3, approximately 2-3 times more genes appeared up-regulated (1,418 vs. 550) or down-regulated (1,603 vs. 735) compared to H1-2. This pattern became more pronounced at day 2 while the number of differentially expressed genes decreased. The specific genes showed an enrichment of biological processes coding for immune system processes, natural killer cell activation and immune response (P = 1 × E-06 up to 9 × E-14). Based on the P values, magnitude and sustained differential gene expression over time, we selected 89 candidate genes for validation using qRT-PCR. Ultimately, 22 genes were confirmed for identification of H1-3 classifications and seven genes for identification of H2-3 classifications using qRT-PCR. For H1-3 classifications, most genes were

  1. Radiation physics, biophysics and radiation biology. Progress report for October 1, 1979-September 30, 1980. [Lead abstract

    SciTech Connect

    Rossi, H.H.; Hall, E.J.

    1980-07-01

    Separate abstracts were prepared for 31 of the 32 papers presented in this progress report. The other paper is represented by an abstract only and deals with field shaping and recalibration of x-ray facilities.

  2. Spectral signature selection for mapping unvegetated soils

    NASA Technical Reports Server (NTRS)

    May, G. A.; Petersen, G. W.

    1975-01-01

    Airborne multispectral scanner data covering the wavelength interval from 0.40-2.60 microns were collected at an altitude of 1000 m above the terrain in southeastern Pennsylvania. Uniform training areas were selected within three sites from this flightline. Soil samples were collected from each site and a procedure developed to allow assignment of scan line and element number from the multispectral scanner data to each sampling location. These soil samples were analyzed on a spectrophotometer and laboratory spectral signatures were derived. After correcting for solar radiation and atmospheric attenuation, the laboratory signatures were compared to the spectral signatures derived from these same soils using multispectral scanner data. Both signatures were used in supervised and unsupervised classification routines. Computer-generated maps using the laboratory and multispectral scanner derived signatures resulted in maps that were similar to maps resulting from field surveys. Approximately 90% agreement was obtained between classification maps produced using multispectral scanner derived signatures and laboratory derived signatures.

  3. NRC TLD Direct Radiation Monitoring Network: Volume 15, No. 1. Progress report, January--March 1995

    SciTech Connect

    Struckmeyer, R.

    1995-05-01

    This report provides the status and results of the NRC Thermoluminescent Dosimeter (TLD) Direct Radiation Monitoring Network. It presents the radiation levels measured in the vicinity of NRC licensed facilities throughout the country for the first quarter of 1995.

  4. NRC TLD direct radiation monitoring network: Progress report, April--June 1997. Volume 17, Number 2

    SciTech Connect

    Struckmeyer, R.

    1997-09-01

    This report provides the status and results of the NRC Thermoluminescent Dosimeter (TLD) Direct Radiation Monitoring Network. It presents the radiation levels measured in the vicinity of NRC licensed facilities throughout the country for the second quarter of 1997.

  5. NRC TLD Direct Radiation Monitoring Network. Progress report, July--September 1993: Volume 13, No. 3

    SciTech Connect

    Struckmeyer, R.

    1993-11-01

    This report provides the status and results of the NRC Thermoluminescent Dosimeter (TLD) Direct Radiation Monitoring Network. It presents the radiation levels measured in the vicinity of NRC licensed facilities throughout the country for the third quarter of 1993.

  6. Progress and Status on the Development of NASA's Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) model

    NASA Astrophysics Data System (ADS)

    Mertens, C. J.; Tobiska, W. K.; Blattnig, S. R.; Kress, B. T.; Wiltberger, M. J.; Solomon, S. C.; Kunches, J.; Murray, J. J.

    2008-12-01

    The NASA Applied Sciences Program recently selected a project for funding through the Research Opportunities in Space and Earth Sciences (ROSES) solicitation. The project objective is to develop a nowcast prediction of air-crew radiation exposure from both background galactic cosmic rays (GCR) and solar energetic particle events (SEP) that may accompany solar storms. The new air-crew radiation exposure model is called the Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) model. NAIRAS will provide global, data-driven, real-time radiation dose predictions of biologically harmful radiation at commercial airline altitudes. Observations are utilized from the ground (neutron monitors), from the atmosphere (the NCEP reanalysis), and from space (NASA/ACE and NOAA/GOES). Atmospheric observations provide the overhead shielding information and the ground- and space-based observations provide boundary conditions on the incident GCR and SEP particle flux distributions for transport and dosimetry simulations. Dose rates are calculated using the parametric AIR (Atmospheric Ionizing Radiation) model and the physics-based HZETRN (High Charge and Energy Transport) code. In this paper we discuss the concept and design of the NAIRAS model, and present recent progress in the implementation and give examples of the model results. Specifically, we show predictions of representative annual background exposure levels and radiation exposure levels for selected SEP events during solar cycle 23, with emphasis on the high-latitude and polar region. We also characterize the suppression of the geomagnetic cutoff rigidity during these storm periods and their subsequent influence on atmospheric radiation exposure. We discuss the key uncertainties and areas that need improvement in both model and data, the timeline for project completion, and access to model results.

  7. Progress on an Updated National Solar Radiation Data Base for the United States: Preprint

    SciTech Connect

    Wilcox, S.; Anderberg, M.; George, R.; Marion, W.; Myers, D.; Renne, D.; Beckman, W.; DeGaetano, A.; Gueymard, C.; Perez, R.; Plantico, M.; Stackhouse, P.; Vignola, F.

    2005-09-01

    In 1992, The National Renewable Energy Laboratory (NREL) released the 1961-1990 National Solar Radiation Data Base (NSRDB), a 30-year set of hourly solar radiation data. In 2003, NREL undertook an NSRDB update project for the decade of 1991-2000.

  8. NRC TLD Direct Radiation Monitoring Network progress report, October--December 1994. Volume 14, No. 4

    SciTech Connect

    Struckmeyer, R.

    1995-03-01

    This report presents the results of the NRC Direct Radiation Monitoring Network for the fourth quarter of 1994. It provides the ambient radiation levels measured in the vicinity of 75 sites throughout the United States. In addition, it describes the equipment used, monitoring station selection criteria, characterization of the dosimeter response, calibration procedures, statistical methods, intercomparison, and quality assurance program.

  9. NRC TLD Direct Radiation Monitoring Network. Progress report, October--December 1996

    SciTech Connect

    Struckmeyer, R.

    1997-03-01

    This report presents the results of the NRC Direct Radiation Monitoring Network for the fourth quarter of 1996. It provides the ambient radiation levels measured in the vicinity of 74 sites throughout the United States. In addition, it describes the equipment used, monitoring station selection criteria, characterization of the dosimeter response, calibration procedures, statistical methods, intercomparison, and quality assurance program. 3 figs., 4 tabs.

  10. Recent Progress in Entry Radiation Measurements in the NASA Ames Electric ARC Shock Tube Facility

    NASA Technical Reports Server (NTRS)

    Cruden, Brett A.

    2012-01-01

    The Electric Arc Shock Tube (EAST) at NASA Ames Research Center is NASA's only working shock tube capable of obtaining conditions representative of entry in a multitude of planetary atmospheres. The facility is capable of mapping spectroscopic signatures of a wide range of planetary entries from the Vacuum Ultraviolet through Mid-Wave Infrared (120-5500 nm). This paper summarizes the tests performed in EAST for Earth, Mars and Venus entries since 2008, then focuses on a specific test case for CO2/N2 mixtures. In particular, the paper will focus on providing information for the proper interpretation of the EAST data.

  11. NREL Solar Radiation Resource Assessment Project: Status and outlook. FY 1991 annual progress report

    SciTech Connect

    Renne, D.; Riordan, C.; Maxwell, E.; Stoffel, T.; Marion, B.; Rymes, M.; Wilcox, S.; Myers, D.

    1992-05-01

    This report summarizes the activities and accomplishments of NREL`s Solar Radiation Resource Assessment Project during fiscal year 1991. Currently, the primary focus of the SRRAP is to produce a 1961--1990 National Solar Radiation Data Base, providing hourly values of global horizontal, diffuse, and direct normal solar radiation at approximately 250 sites around the United States. Because these solar radiation quantities have been measured intermittently at only about 50 of these sites, models were developed and applied to the majority of the stations to provide estimates of these parameters. Although approximately 93% of the data base consists of modeled data this represents a significant improvement over the SOLMET/ERSATZ 1952--1975 data base. The magnitude and importance of this activity are such that the majority of SRRAP human and financial in many other activities, which are reported here. These include the continued maintenance of a solar radiation monitoring network in the southeast United States at six Historically Black Colleges and Universities (HBCU`s), the transfer of solar radiation resource assessment technology through a variety of activities, participation in international programs, and the maintenance and operation of NREL`s Solar Radiation Research Laboratory. 17 refs.

  12. NRC TLD direct radiation monitoring network: Volume 15, No. 3. Progress report, July--September 1995

    SciTech Connect

    Struckmeyer, R.

    1995-12-01

    The US Nuclear Regulatory Commission (NRC) Direct Radiation Monitoring Network is operated by the NRC in cooperation with participating states to provide continuous measurement of the ambient radiation levels around licensed NRC facilities, primarily power reactors. Ambient radiation levels result from naturally occurring radionuclides present in the soil, cosmic radiation constantly bombarding the earth from outer space, and the contribution, if any, from the monitored facilities and other man-made sources. The Network is intended to measure radiation levels during routine facility operations and to establish background radiation levels used to assess the radiological impact of an unusual condition, such as an accident. This report presents the radiation levels measured around all facilities in the Network for the third quarter of 1995. A complete listing of the site facilities monitored is included. In some instances, two power reactor facilities are monitored by the same set of dosimeters (e.g., Kewaunee and Point Beach). All radiation measurements are made using small, passive detectors called therinoluminescent dosimeters (TLDs), which provide a quantitative measurement of the radiation levels in the area in which they are placed. Each site is monitored by arranging approximately 40 to 50 TLD stations in two concentric rings extending to about five miles from the facility. All TLD stations are outside the site boundary of the facility. A complete description of the program can be found in NUREG-0837, Volume 2, Number 4. A similar description can also be found in the fourth quarter report of each subsequent year. The National Institute of Standards and Technology (formerly the National Bureau of Standards) has performed an independent study of the following characteristics of the NRC dosimetry system; energy response, angular dependence, temperature and humidity sensitivity, fading, light dependence, self-irradiation, and reproducibility.

  13. SERI Solar Radiation Resource Assessment Project: Fiscal Year 1990 Annual Progress Report

    SciTech Connect

    Riordan, C; Maxwell, E; Stoffel, T; Rymes, M; Wilcox, S

    1991-07-01

    The purpose of the Solar Radiation Resource Project is to help meet the needs of the public, government, industry, and utilities for solar radiation data, models, and assessments as required to develop, design, deploy, and operate solar energy conversion systems. The project scientists produce information on the spatial (geographic), temporal (hourly, daily, and seasonal), and spectral (wavelength distribution) variability of solar radiation at different locations in the United States. Resources committed to the project in FY 1990 supported about four staff members, including part-time administrative support. With these resources, the staff must concentrate on solar radiation resource assessment in the United States; funds do not allow for significant efforts to respond to a common need for improved worldwide data. 34 refs., 21 figs., 6 tabs.

  14. Loratadine dysregulates cell cycle progression and enhances the effect of radiation in human tumor cell lines

    PubMed Central

    2010-01-01

    Background The histamine receptor-1 (H1)-antagonist, loratadine has been shown to inhibit growth of human colon cancer xenografts in part due to cell cycle arrest in G2/M. Since this is a radiation sensitive phase of the cell cycle, we sought to determine if loratadine modifies radiosensitivity in several human tumor cell lines with emphasis on human colon carcinoma (HT29). Methods Cells were treated with several doses of loratadine at several time points before and after exposure to radiation. Radiation dose modifying factors (DMF) were determined using full radiation dose response survival curves. Cell cycle phase was determined by flow cytometry and the expression of the cell cycle-associated proteins Chk1, pChk1ser345, and Cyclin B was analyzed by western blot. Results Loratadine pre-treatment of exponentially growing cells (75 μM, 24 hours) increased radiation-induced cytotoxicity yielding a radiation DMF of 1.95. However, treatment of plateau phase cells also yielded a DMF of 1.3 suggesting that mechanisms other than cell cycle arrest also contribute to loratadine-mediated radiation modification. Like irradiation, loratadine initially induced G2/M arrest and activation of the cell-cycle associated protein Chk1 to pChk1ser345, however a subsequent decrease in expression of total Chk1 and Cyclin B correlated with abrogation of the G2/M checkpoint. Analysis of DNA repair enzyme expression and DNA fragmentation revealed a distinct pattern of DNA damage in loratadine-treated cells in addition to enhanced radiation-induced damage. Taken together, these data suggest that the observed effects of loratadine are multifactorial in that loratadine 1) directly damages DNA, 2) activates Chk1 thereby promoting G2/M arrest making cells more susceptible to radiation-induced DNA damage and, 3) downregulates total Chk1 and Cyclin B abrogating the radiation-induced G2/M checkpoint and allowing cells to re-enter the cell cycle despite the persistence of damaged DNA. Conclusions

  15. Investigation of the coherent synchrotron radiation spectrum as a probe of charge dynamics. Progress report

    SciTech Connect

    Sievers, A.J.; Tigner, M.

    1993-02-01

    Coherent synchrotron, Cherenkov and transition radiation have generated and measured in the far infrared spectral region. This work represents the first identification and separation of the Cherenkov and transition radiation components with transition radiation producing the strongest signal. High-intensity picosecond pulses of radiation are observed for all three sources. The angular dependence in the mm wave region is not the same as that given by high-frequency radiation expressions since the wavelength and the beam radiator size are comparable; hence diffraction effects are important. A prototype polarizing Michelson interferometer has been designed, constructed and is now being tested. The diffraction-limited design meets the demands of the rigorous space and experimental conditions in the linac area. The instrument is of rugged constructed using retroreflectors and thus is optically stable for long periods of time. It contains both reference and interferogram detectors to minimize the influence of linac drifts on the data analysis. To eliminate the intensity loss at low frequencies due to diffraction and waveguide effects the next generation of interferometer and detector will have 2x larger apertures.

  16. Developing composite signatures

    NASA Astrophysics Data System (ADS)

    Hawley, Chadwick T.; Carpenter, Tom; Cappelaere, Patrice G.; Frye, Stu; Lemoigne-Stewart, Jacqueline J.; Mandle, Dan; Montgomery, Sarah; Williams-Bess, Autumn

    2011-06-01

    A composite signature is a group of signatures that are related in such a way to more completely or further define a target or operational endeavor at a higher fidelity. This paper explores the merits of using composite signatures, in lieu of waiting for opportunities for the more elusive diagnostic signatures, to satisfy key essential elements of information Keywords: signature, composite signature, civil disaster (EEI) associated with civil disaster-related problems. It discusses efforts to refine composite signature development methodology and quantify the relative value of composite vs. diagnostic signatures. The objectives are to: 1) investigate and develop innovative composite signatures associated with civil disasters, including physical, chemical and pattern/behavioral; 2) explore the feasibility of collecting representative composite signatures using current and emerging intelligence, surveillance, and reconnaissance (ISR) collection architectures leveraging civilian and commercial architectures; and 3) collaborate extensively with scientists and engineers from U.S. government organizations and laboratories, the defense industry, and academic institutions.

  17. Progress in Projecting Solar Radiation at the Earth's Surface in Climate Models

    NASA Astrophysics Data System (ADS)

    Collins, W.; Fildier, B.; Feldman, D.

    2015-12-01

    Projecting changes in solar radiation at the Earth's surface in futureclimates is a critical input to forecast surface irradiance for solarenergy. We demonstrate the current state of the art using theensemble of opportunity assembled for the Coupled ModelIntercomparison Project (CMIP5) and the Fifth Assessment Report (AR5)of the Intergovernmental Panel on Climate Change (IPCC). The reliability of these projections depends upon the accuracy of theunderlying radiation codes, the fidelity of these codes to themeasured optical properties of key radiatively active atmosphericconstituents, and the realism of future projections of theseatmospheric constituents. These constituents include aerosols,clouds, water vapor, greenhouse gases that absorb near-infraredsunlight. Since the realism of future projections of anthropogenicaerosol species is contingent on the underlying scenario, we focus onthe other challenges in forecasting surface irradiance. Regarding accuracy, we demonstrate that current GCM shortwaveparameterizations often exhibit quite small errors relative tobenchmark radiative transfer codes. In addition, recent work hasbracketed the uncertainties in solar irradiance associated withcomplex cloud geometries. There is also an emerging consensus howcloud radiative effects will evolve in a warmer climate. However,there is evidence that current GCM codes still exhibit systematicerrors in the near-infrared water vapor bands, particularly for moistsub-tropical atmospheres. These errors will become more acute aswater vapor feedbacks, combined with global warming, increase thetotal precipitable water in the Earth's atmosphere.

  18. Non-DBS DNA Repair Genes Regulate Radiation-induced Cytogenetic Damage Repair and Cell Cycle Progression

    NASA Technical Reports Server (NTRS)

    Zhang, Ye; Rohde, Larry H.; Emami, Kamal; Casey, Rachael; Wu, Honglu

    2008-01-01

    Changes of gene expression profile are one of the most important biological responses in living cells after ionizing radiation (IR) exposure. Although some studies have shown that genes up-regulated by IR may play important roles in DNA damage repair, the relationship between the regulation of gene expression by IR, particularly genes not known for their roles in DSB repair, and its impact on cytogenetic responses has not been systematically studied. In the present study, the expression of 25 genes selected on the basis of their transcriptional changes in response to IR was individually knocked down by transfection with small interfering RNA in human fibroblast cells. The purpose of this study is to identify new roles of these selected genes on regulating DSB repair and cell cycle progression , as measured in the micronuclei formation and chromosome aberration. In response to IR, the formation of MN was significantly increased by suppressed expression of 5 genes: Ku70 in the DSB repair pathway, XPA in the NER pathway, RPA1 in the MMR pathway, and RAD17 and RBBP8 in cell cycle control. Knocked-down expression of 4 genes (MRE11A, RAD51 in the DSB pathway, SESN1, and SUMO1) significantly inhibited cell cycle progression, possibly because of severe impairment of DNA damage repair. Furthermore, loss of XPA, P21, or MLH1 expression resulted in both significantly enhanced cell cycle progression and increased yields of chromosome aberrations, indicating that these gene products modulate both cell cycle control and DNA damage repair. Most of the 11 genes that affected cytogenetic responses are not known to have clear roles influencing DBS repair. Nine of these 11 genes were up-regulated in cells exposed to gamma radiation, suggesting that genes transcriptionally modulated by IR were critical to regulate the biological consequences after IR.

  19. ANNUAL PROGRESS REPORT. MARKERS OF THE LOW-DOSE RADIATION RESPONSE

    EPA Science Inventory

    One of the major challenges in the field of radiation biology is to correlate the results of biochemical studies with the process of DNA repair as it occurs in the living cell. The overall goal of this project is to develop better methods for visualizing DNA double-strand breaks ...

  20. ANNUAL PROGRESS REPORT. RADIATION EFFECTS ON SORPTION AND MOBILIZATION OF RADIONUCLIDES DURING TRANSPORT THROUGH THE GEOSPHERE

    EPA Science Inventory

    This research program has been aimed at the understanding of radiation effects on the sorption/desorption and ion exchange capacity of radionuclides in two major groups of geologic materials, clays and zeolites. The experiments are designed for investigating the effects of ionizi...

  1. NREL Solar Radiation Resource Assessment Project: Status and outlook. Annual progress report, FY 1992

    SciTech Connect

    Renne, D.; Maxwell, E.; Stoffel, T.; Marion, B.; Rymes, M.; Wilcox, S.; Myers, D.; Riordan, C.; Hammond, E.; Ismailidis, T.

    1993-06-01

    This annual report summaries the activities and accomplishments of the Solar Radiation Resource Assessment Project during fiscal year 1992 (1 October to 30 September 1992). Managed by the Analytic Studies Division of the National Renewable Energy Laboratory, this project is the major activity of the US Department of Energy`s Resource Assessment Program.

  2. Response of a forest ecotone to ionizing radiation. Progress report, October 15, 1980-October 14, 1981

    SciTech Connect

    Murphy, P.G.; Sharitz, R.R.

    1981-06-01

    The primary objectives of this study are to determine the effects of ionizing radiation on the tree species composition of the ecotone between two forest types in northern Wisconsin and to compare the postirradiation recovery of the tree flora in the ecotone with that in the bordering forest types. Relatively distinct ecotones constitute a spatially significant portion of many second-growth forest ecosystems. Belt transects concentric to the radiation source (/sup 137/Cs) are being used to measure compositional changes in the ecotone from aspen to maple-birch forest types. Information available includes population densities by size class, importance values, and diversity values. Estimates of leaf area index and leaf litter production, by species, have also been obtained. Succession in the radiation areas is presently under study. To date, redevelopment of forest vegetation at up to 20 m from the radiation source has been slowed significantly by the vigorous colonization of heliophytes. Sampling for 1980-81 is on schedule. In all three areas competition from successional ground vegetation has continued to delay re-establishment of tree seedlings under the opened canopy at 10 m. In this regard, only the aspen area has shown any signs of recovering, having experienced an influx of red maple seedlings in 1978. Even that area, however, is still less than half preirradiation levels with respect to seedling densities. As unusually high ratio of shrub leaf litter to tree leaf litter in the 10 to 20 m area reflects the displacement of canopy species by successional shrubs. As the overall impact of the radiation stress depends on the rate of forest re-establishment, observations will continue for several more years.

  3. The AE9/AP9/SPM Next Generation Radiation Specification Models - Progress Report

    NASA Astrophysics Data System (ADS)

    O'Brien, Paul; Johnston, William Robert; Huston, Stuart; Guild, Timothy

    2016-07-01

    The AE9/AP9/SPM model has now been released to the global satellite design community, with a recent update to version 1.2. We are working on incorporating new data sources, such as AZUR and NASA's Van Allen Probes, while also addressing critiques raised by the science and engineering communities. In particular, we are investigating discrepancies for protons at low altitude and electrons at geostationary altitudes. Finally, we are scoping out architectural improvements to enable features requested by industry: improved stitching between the plasma and radiation models, local time dependence in the plasma model, longitude dependence in the electron radiation model, and solar cycle variation in the low altitude protons. We provide a brief update on the status of the model, discrepancy investigations, and plans for the future.

  4. Genetic variation in resistance to ionizing radiation. Technical progress report, January--December 1991

    SciTech Connect

    Ayala, F.J.

    1991-06-24

    We proposed an investigation of genetically-determined individual differences in sensitivity to ionizing radiation. The model organism is Drosophila melanogaster. The gene coding for Cu,Zn superoxide dismutase (SOD) is the target locus, but the effects of variation in other components of the genome that modulate SOD levels are also taken into account. SOD scavenges oxygen radicals generated during exposure to ionizing radiation. It has been shown to protect against ionizing radiation damage to DNA, viruses, bacteria, mammalian cells, whole mice, and Drosophila. Two alleles, S and F, are commonly found in natural populations of D. melanogaster; in addition we have isolated from a natural population ``null`` (CA1) mutant that yields only 3.5% of normal SOD activity. The S, F, and CA1 alleles provide an ideal model system to investigate SOD-dependent radioresistance, because each allele yields different levels of SOD, so that S > F >> CA1. The roles of SOD level in radioresistance are being investigated in a series of experiments that measure the somatic and germ-line effects of increasing doses of ionizing radiation. In addition, we have pursued an unexpected genetic event-namely the nearly simultaneous transformation of several lines homozygous for the SOD ``null`` allele into predominately S lines. Using specifically designed probes and DNA amplification by means of the Tag polymerase chain reaction (PCR) we have shown that (1) the null allele was still present in the transformed lines, but was being gradually replaced by the S allele as a consequence of natural selection; and (2) that the transformation was due to the spontaneous deletion of a 0.68 Kb truncated P-element, the insertion of which is characteristic of the CA1 null allele.

  5. Serial Intravitreal Bevacizumab Injections Slow the Progression of Radiation Maculopathy Following Iodine-125 Plaque Radiotherapy

    PubMed Central

    Stacey, Andrew W.; Demirci, Hakan

    2016-01-01

    Background and Objective: To assess the outcomes of intravitreal bevacizumab injection in the management of radiation maculopathy secondary to plaque radiotherapy, and to identify optimal treatment strategies. Study Design: A retrospective review of all choroidal melanoma patients at one referral center who were treated with plaque radiotherapy, subsequently developed radiation maculopathy, and received intravitreal bevacizumab. Results: A total of 31 patients were identified. The mean visual acuity decreased three Snellen lines in the year leading up to the first bevacizumab injection. After initiating injection therapy, the mean visual acuity remained stable for 9 months. The change in visual acuity of patients who received injections within 90 days of previous injections was significantly better than the visual acuity of those who received injections more than 90 days apart (p=0.0003). Patients who demonstrated late-phase macular leakage on fluorescein angiography at the time of the first bevacizumab injection had better long-term visual acuity outcomes than patients who had no evidence of macular leakage (average of one line improvement of vision vs. ten line loss of vision, p=0.03). Conclusions: Intravitreal bevacizumab injection was effective in stabilizing visual acuity in patients with radiation maculopathy. Patients benefited most from injections administered every 90 days or sooner. Fluorescein angiography can help identify patients who will respond favorably to treatment. PMID:27053973

  6. The RAVAN CubeSat mission: Progress toward a new measurement of Earth outgoing radiation

    NASA Astrophysics Data System (ADS)

    Swartz, B. H.; Dyrud, L. P.; Lorentz, S. R.; Wu, D. L.; Wiscombe, W. J.; Papadakis, S.; Huang, P. M.; Smith, A.; Deglau, D.

    2014-12-01

    The Earth radiation imbalance (ERI) is the single most important quantity for predicting the course of climate change over the next century. The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat mission, funded by NASA's Earth Science Technology Office, will demonstrate an affordable, accurate radiometer that directly measures Earth-leaving fluxes of total and solar-reflected radiation. The objective of RAVAN is to demonstrate that a compact spaceborne radiometer that is absolutely accurate to NIST-traceable standards can be built for low cost. The key technologies that enable a radiometer with all these attributes are: a vertically aligned carbon nanotube (VACNT) absorber and a gallium fixed-point blackbody as a built-in calibration source. VACNTs are exceedingly black and spectrally flat, making them ideal radiometer absorbers. We present results from the fabrication and calibration of the RAVAN radiometer and plans for CubeSat hosting and launch. RAVAN will help enable the development of a constellation Earth radiation budget mission that can provide the measurements needed for superior predictions of future climate change.

  7. Stepwise Progress in Epidermal Growth Factor Receptor/Radiation Studies for Head and Neck Cancer

    SciTech Connect

    Harari, Paul M.

    2007-10-01

    The U.S. Food and Drug Administration approval of four new epidermal growth factor receptor (EGFR) inhibitors for cancer therapy (cetuximab, panitumumab, gefitinib, and erlotinib) over the last 3 years is a remarkable milestone in oncology. Indeed, molecular inhibition of EGFR signaling represents one of the most promising current arenas for the development of molecular-targeted cancer therapies. Epidermal growth factor receptor inhibitors from both the monoclonal antibody and tyrosine kinase inhibitor class have demonstrated clinical activity in the treatment of a broad spectrum of common human malignancies. For the discipline of radiation oncology, the 2006 report of a phase III trial demonstrating a survival advantage for advanced head and neck cancer patients with the addition of weekly cetuximab during a 7-week course of radiation is particularly gratifying. Indeed, this is the first phase III trial to confirm a survival advantage with the addition of a molecular-targeted agent to radiation. Furthermore, this result seems to have been achieved with only a modest increment in overall treatment toxicity and with very high compliance to the prescribed treatment regimen. Nevertheless, much remains to be learned regarding the rational integration of EGFR inhibitors into cancer treatment regimens, as well as methods to optimize the selection of patients most likely to benefit from EGFR inhibitor strategies.

  8. Anonymous Signatures Revisited

    NASA Astrophysics Data System (ADS)

    Saraswat, Vishal; Yun, Aaram

    We revisit the notion of the anonymous signature, first formalized by Yang, Wong, Deng and Wang [10], and then further developed by Fischlin [4] and Zhang and Imai [11]. We present a new formalism of anonymous signature, where instead of the message, a part of the signature is withheld to maintain anonymity. We introduce the notion unpretendability to guarantee infeasibility for someone other than the correct signer to pretend authorship of the message and signature. Our definition retains applicability for all previous applications of the anonymous signature, provides stronger security, and is conceptually simpler. We give a generic construction from any ordinary signature scheme, and also show that the short signature scheme by Boneh and Boyen [2] can be naturally regarded as such a secure anonymous signature scheme according to our formalism.

  9. Radiation promotes colorectal cancer initiation and progression by inducing senescence-associated inflammatory responses.

    PubMed

    Kim, S B; Bozeman, R G; Kaisani, A; Kim, W; Zhang, L; Richardson, J A; Wright, W E; Shay, J W

    2016-06-30

    Proton radiotherapy is becoming more common as protons induce more precise DNA damage at the tumor site with reduced side effects to adjacent normal tissues. However, the long-term biological effects of proton irradiation in cancer initiation compared with conventional photon irradiation are poorly characterized. In this study, using a human familial adenomatous polyposis syndrome susceptible mouse model, we show that whole-body irradiation with protons are more effective in inducing senescence-associated inflammatory responses (SIRs), which are involved in colon cancer initiation and progression. After proton irradiation, a subset of SIR genes (Troy, Sox17, Opg, Faim2, Lpo, Tlr2 and Ptges) and a gene known to be involved in invasiveness (Plat), along with the senescence-associated gene (P19Arf), are markedly increased. Following these changes, loss of Casein kinase Iα and induction of chronic DNA damage and TP53 mutations are increased compared with X-ray irradiation. Proton irradiation also increases the number of colonic polyps, carcinomas and invasive adenocarcinomas. Pretreatment with the non-steroidal anti-inflammatory drug, 2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oic acid-ethyl amide (CDDO-EA), reduces proton irradiation-associated SIR and tumorigenesis. Thus exposure to proton irradiation elicits significant changes in colorectal cancer initiation and progression that can be mitigated using CDDO-EA. PMID:26477319

  10. Radiation Promotes Colorectal Cancer Initiation and Progression by Inducing Senescence-Associated Inflammatory Responses

    PubMed Central

    Kim, Sang Bum; Bozeman, Ronald; Kaisani, Aadil; Kim, Wanil; Zhang, Lu; Richardson, James A.; Wright, Woodring E.; Shay, Jerry W.

    2015-01-01

    Proton radiotherapy is becoming more common since protons induce more precise DNA damage at the tumor site with reduced side effects to adjacent normal tissues. However, the long-term biological effects of proton irradiation in cancer initiation compared to conventional photon irradiation are poorly characterized. In this study, using a human familial adenomatous polyposis syndrome susceptible mouse model, we show that whole body irradiation with protons are more effective in inducing senescence-associated inflammatory responses (SIR) which are involved in colon cancer initiation and progression. After proton irradiation, a subset of SIR genes (Troy, Sox17, Opg, Faim2, Lpo, Tlr2 and Ptges) and a gene known to be involved in invasiveness (Plat), along with the senescence associated gene (P19Arf) are markedly increased. Following these changes loss of Casein kinase Iα (CKIα) and induction of chronic DNA damage and TP53 mutations are increased compared to x-ray irradiation. Proton irradiation also increases the number of colonic polyps, carcinomas and invasive adenocarcinomas. Pretreatment with the non-steroidal anti-inflammatory drug, CDDO-EA, reduces proton irradiation associated SIR and tumorigenesis. Thus, exposure to proton irradiation elicits significant changes in colorectal cancer initiation and progression that can be mitigated using CDDO-EA. PMID:26477319

  11. Progress on the Flash X-Ray Optical Transition Radiation Diagnostic

    SciTech Connect

    Tang, V; Houck, T; Brown, C

    2008-03-30

    This document summarizes the Flash X-Ray accelerator (FXR) optical transition radiation (OTR) spot-size diagnostics efforts in FY07. During this year, new analysis, simulation, and experimental approaches were utilized to interpret OTR spot data from both dielectric foils such as Kapton (VN type) and metal coated foils. Significant new findings of the intricacies involved in the diagnostic and of FXR operational issues were achieved. Geometry and temperature based effects were found to affect the beam image profiles from the OTR foils. These effects must be taken into account in order to deduce accurately the beam current density profile.

  12. Improved Cloud-Radiation Parameterization for GCMs through the ARM Program. Final Progress Report

    SciTech Connect

    Kiehl, J. T.

    2004-03-31

    Climate sensitivity is an important determinant of climate change. In terms of global climate response, climate sensitivity determines the magnitude of climate change due to radiative forcings by greenhouse gases. The IPCC reports have pointed out that much of the uncertainty in climate projections can be attributed to the disparity in modeled climate sensitivity. Thus, it is imperative to understand the magnitude of climate sensitivity for a given model, and an understanding of what role physical processes play in determining the models particular climate sensitivity.

  13. Ionizing radiation induced catalysis on metal oxide particles. 1998 annual progress report

    SciTech Connect

    Fryberger, T.; Chambers, S.A.; Daschbach, J.L.; Henderson, M.A.; Peden, C.H.F.; Su, Y.; Wang, Y.

    1998-06-01

    'High-level radioactive waste storage tanks within DOE sites contain significant amounts of organic components (solid and liquid phases) in the form of solvents, extractants, complexing agents, process chemicals, cleaning agents and a variety of miscellaneous compounds. These organics pose several safety and pretreatment concerns, particularly for the Hanford tank waste. Remediation technologies are needed that significantly reduce the amounts of problem organics without resulting in toxic or flammable gas emissions, and without requiring thermal treatments. These restrictions pose serious technological barriers for current organic destruction methods which utilize oxidation achieved by thermal or chemical activation. This project focuses on using ionizing radiation (a,b,g) to catalytically destroy organics over oxide materials through reduction/oxidation (redox) chemistry resulting from electron-hole (e{sup -}/h{sup +}) pair generation. Conceptually this process is an extension of visible and near-UV photocatalytic processes known to occur at the interfaces of narrow bandgap semiconductors in both solution and gas phases. In these processes, an electron is excited across the energy gap between the filled and empty states in the semiconductor. The excited electron does reductive chemistry and the hole (where the electron was excited from) does oxidative chemistry. The energy separation between the hole and the excited electron reflects the redox capability of the e{sup -}/h{sup +} pair, and is dictated by the energy of the absorbed photon and the bandgap of the material. The use of ionizing radiation overcomes optical transparency limitations associated with visible and near-UV illumination (g-rays penetrate much farther into a solution than UV/Vis light), and permits the use of wider bandgap materials (such as ZrO{sub 2}) which possess potentially greater redox capabilities than those with narrow bandgap materials. Experiments have been aimed at understanding the

  14. Inhibition of TGF-β with neutralizing antibodies prevents radiation-induced acceleration of metastatic cancer progression

    PubMed Central

    Biswas, Swati; Guix, Marta; Rinehart, Cammie; Dugger, Teresa C.; Chytil, Anna; Moses, Harold L.; Freeman, Michael L.; Arteaga, Carlos L.

    2007-01-01

    We investigated whether TGF-β induced by anticancer therapies accelerates tumor progression. Using the MMTV/PyVmT transgenic model of metastatic breast cancer, we show that administration of ionizing radiation or doxorubicin caused increased circulating levels of TGF-β1 as well as increased circulating tumor cells and lung metastases. These effects were abrogated by administration of a neutralizing pan–TGF-β antibody. Circulating polyomavirus middle T antigen–expressing tumor cells did not grow ex vivo in the presence of the TGF-β antibody, suggesting autocrine TGF-β is a survival signal in these cells. Radiation failed to enhance lung metastases in mice bearing tumors that lack the type II TGF-β receptor, suggesting that the increase in metastases was due, at least in part, to a direct effect of TGF-β on the cancer cells. These data implicate TGF-β induced by anticancer therapy as a prometastatic signal in tumor cells and provide a rationale for the simultaneous use of these therapies in combination with TGF-β inhibitors. PMID:17415413

  15. The oncogenic action of ionizing radiation on rat skin. Final progress report, May 1, 1990--April 30, 1992

    SciTech Connect

    Burns, F.J.; Garte, S.J.

    1992-12-31

    The multistage theory of carcinogenesis specifies that cells progress to cancer through a series of discrete, irreversible genetic alterations, but data on radiation-induced cancer incidence in rat skin suggests that an intermediate repairable alteration may occur. Data are presented on cancer induction in rat skin exposed to an electron beam (LET=0.34 keV/{mu}), a neon ion beam (LET=45) or an argon ion beam (LET=125). The rats were observed for tumors at least 78 weeks with squamous and basal cell carcinomas observed. The total cancer yield was fitted by the quadratic equation, and the equation parameters were estimated by linear regression for each type of radiation. Analysis of the DNA from the electron-induced carcinomas indicated that K-ras and/or c-myc oncogenes were activated. In situ hybridization indicated that the cancers contain subpopulations of cells with differing amounts of c-myc and H-ras amplification. The results are consistent with the idea that ionizing radiation produces stable, carcinogenically relevant lesions via 2 repairable events at low LET and via a non-repairable linked event pathway at high LET; either pathway may advance the cell by 1 stage. The proliferative response of rat epidermis following exposure to ionizing radiation was quantified by injection of {sup 14}C-thymidine. The return of these cells to S-phase a second time was detected by a second label ({sup 3}H). When the labeled cells were in G1-phase, the dorsal skin was irradiated with X-rays. All labeling indices were determined. The {sup 14}C labeling index was constant and unaffected by the radiation. The proportion of all cells entering S-phase averaged 3.5% at 18 hr and increased after 44, 52 and 75 hr to average levels of 11.8%, 5. 3%, and 6.6% at 0, 10 and 25 Gy respectively. The proportion of S-phase cells labeled with {sup 14}C increased after 42 hr and remained relatively constant thereafter.

  16. Progress on Updating the 1961-1990 National Solar Radiation Database

    NASA Technical Reports Server (NTRS)

    Renne, D.; Wilcox, S.; Marion, B.; George, R.; Myers, D.

    2003-01-01

    The 1961-1990 National Solar Radiation Data Base (NSRDB) provides a 30-year climate summary and solar characterization of 239 locations throughout the United States. Over the past several years, the National Renewable Energy Laboratory (NREL) has received numerous inquiries from a range of constituents as to whether an update of the database to include the 1990s will be developed. However, there are formidable challenges to creating an update of the serially complete station-specific database for the 1971-2000 period. During the 1990s, the National Weather Service changed its observational procedures from a human-based to an automated system, resulting in the loss of important input variables to the model used to complete the 1961-1990 NSRDB. As a result, alternative techniques are required for an update that covers the 1990s. This paper examines several alternative approaches for creating this update and describes preliminary NREL plans for implementing the update.

  17. A phase II trial of PTK787/ZK 222584 in recurrent or progressive radiation and surgery refractory meningiomas.

    PubMed

    Raizer, Jeffrey J; Grimm, Sean A; Rademaker, Alfred; Chandler, James P; Muro, Kenji; Helenowski, Irene; Rice, Laurie; McCarthy, Katie; Johnston, Sandra K; Mrugala, Maciej M; Chamberlain, Marc

    2014-03-01

    When surgery and radiation are no longer treatment options, salvage systemic therapy has been used for recurrent meningiomas with little compelling evidence to suggest effectiveness. Patients with surgery and radiation refractory recurrent meningiomas were treated with the oral multifunctional tyrosine kinase inhibitor PTK787/ZK 222584 (PTK787) at a dose of 500 mg twice a day. Each treatment cycle was 4 weeks with MRI done every 8 weeks. Twenty-five patients (14 men; 11 women) with a median age of 59 years and KPS of 80 were treated. Meningioma WHO Grade was I in 2 patients, II in 14 patients and III in 8 patients; 1 patient had a hemangiopericytoma. All patients had prior surgery, external beam radiation therapy or radiosurgery and 11 patients prior systemic chemotherapy. Median number of cycles of PTK 787 administered was 4 (range <1-22). Best response in the 22 evaluable patients was stable disease in 15 (68.2 %). Predominant PTK787 related toxicities included fatigue (60 %), hypertension (24 %) and elevated transaminases (24 %). Grade II patients had a progression free survival (PFS)-6 of 64.3 %, a median PFS of 6.5 months and an overall survival (OS) of 26.0 months; grade III patients had a PFS-6 of 37.5 %, median PFS of 3.6 months and OS 23 months. PTK787 was modestly toxic at the dose of 500 mg administered twice per day. Activity as determined by PFS-6 suggests that targeting PDGF/VEGF pathway warrants further investigation. PMID:24449400

  18. Progressive alterations of central nervous system structure and function are caused by charged particle radiation

    NASA Astrophysics Data System (ADS)

    Nelson, G. A.; Cns Nscor Team

    A new NASA-sponsored program project (NSCOR) has been organized to conduct the first comprehensive investigation of the response of a mammalian brain structure (mouse hippocampus) to charged-particle radiation. The NSCOR collaboration has three main goals. The first goal is to quantify the time- and dose-dependent changes in cellular composition and architecture. By using stereology on preserved brains, subsets of cells (neurons, glia, endothelia and stem cells) will be quantified out to 2 years after irradiation with accelerated protons and iron ions. To further characterize changes in vasculature architecture a polymer infusion technique will be used to produce a three-dimensional vasculature cast that then will be mapped by x-ray tomography to determine topological changes, and microscopic infarcts associated with amyloid protein deposits. The 2nd goal is to quantify hippocampal function(s). The primary measurement of function will be extracellular electrical recordings from hippocampal ``brain slices'' that reflect underlying functions such as connectivity, action potential generation & conduction, and neurotransmitter formation, secretion, and uptake. Individual nerve membrane properties will be assessed by ``patch clamp'' recordings. Two non-invasive methods will evaluate brain function and the evolution of changes with time. Electroencephalograms will map macroscopic spontaneous electrical activity while two state-of-the-art MRI magnetization sequences will visualize and quantify local oxygen utilization and white matter fiber tracts structural integrity. To quantify the brains' overall performance under stress, animals will receive a systemic shock mediated by the immune system in the form of a reaction to lipopolysaccharide. A second strategy will employ the APP23 transgenic mouse that develops the pathological changes associated with Alzheimer's disease. Measurements of irradiated mice will determine whether radiation exposure affects the latency and

  19. Cell cycle progression in denV-transfected murine fibroblasts exposed to ultraviolet radiation.

    PubMed

    Kusewitt, D F; Budge, C L; Nolla, H A; Edwards, B S; Ley, R D

    1992-09-01

    Repair-proficient murine fibroblasts transfected with the denV gene of bacteriophage T4 repaired 70-80% of pyrimidine dimers within 24 h after exposure to 150 J/m2 ultraviolet radiation (UVR) from an FS-40 sunlamp. Under the same conditions, control cells repaired only about 20% of UVR-induced pyrimidine dimers. After UVR exposure, both control and denV-transfected cells exhibited some degree of DNA-synthesis inhibition, as determined by flow cytometric analysis of cell-cycle kinetics in propidium iodide-stained cells. DenV-transfected cells had a longer and more profound S phase arrest than control cells, but both control and denV-transfected cells had largely recovered from UVR effects on cell-cycle kinetics by 48 h after UVR exposure. Inhibition of DNA synthesis by UVR was also measured by determining post-UVR incorporation of bromodeoxyuridine (BrdU). The amount of BrdU incorporated was quantitated by determining with flow cytometry the quenching of Hoechst dye 33342 by BrdU incorporated in cellular DNA. DenV-transfected cells showed more marked inhibition of BrdU incorporation after low fluences of UVR than control cells. Differences between denV-transfected and control cells in cell-cycle kinetics following UVR exposure may be related to differences in mechanisms of repair when excision repair of pyrimidine dimers is initiated by endonuclease V instead of cellular repair enzymes. PMID:1380650

  20. Response of a forest ecotone to ionizing radiation. Progress report, April 15, 1983-April 14, 1984

    SciTech Connect

    Murphy, P.G.; Sharitz, R.R.

    1983-11-01

    Compositional and structural characteristics of three forest types, including aspen dominated, maple-birch dominated, and an intervening ecotone (midecotone), were studied before and after irradiation in northern Wisconsin. In all three areas, the density of seedlings at 10 m was greatly reduced within a year following the 1972 radiation event. In the maple-birch area seedlings were virtually absent at 10 m until 1982 and 1983 when their numbers were comparable to preirradiation levels. In the aspen and midecotone areas 1983 seedling densities at 10 m were only 50 and 17%, respectively, of the preirradiation levels. Woody plants of tree stature were eliminated at 10 m in all three areas within two years of irradiation but by 1982 only the aspen area lacked plants in this size class. In 1982 total leaf litter production was 26 and 63% below 1971 preirradiation levels at 10 m in the aspen and maple-birch areas, respectively. But at 10 m in the midecotone, it had increased, relative to 1971, by 27%. The ratio of shrub to tree leaf litter continues to decline as the heavily irradiated zone of all three areas continues to be recolonized by tree species and the canopy at 20 m continues to fill out. Present studeis emphasize the rate at which the three areas continue to be recolonized, and the composition of the recolonizing flora, relative to the preirradiation forest.

  1. Human genetic marker for resistance to radiations and chemicals. 1997 annual progress report

    SciTech Connect

    Lieberman, H.B.

    1997-01-01

    'The specific aims listed in the original application will essentially be pursued as indicated. The major goal of the grant is to characterize a human homologue of the fission yeast Schizosaccharomyces pombe rad9 checkpoint control, radioresistance and chemoresistance gene, which is called HRAD9. The purpose is to gain information about the gene, including its structure and function, such that it can potentially be developed as a human genetic marker indicative of hypersensitivity to the deleterious effects associated with exposure to radiations or certain chemicals. The specific aims are divided into two major sections. The first section includes experiments designed to characterize the HRAD9 gene at the molecular level. Specifically, the genomic version of the gene will be isolated and its DNA sequence determined, in vitro mutagenesis will be used to assess structure/function relationships, and expression in cells and tissues will be examined. The second major set of aims focuses on determining the role of HRAD9 in radio/chemoresponsiveness and cancer. For this aim, human HRAD9 mutants will be constructed and characterized. In addition, the status of HRAD9 in cancer cells and tissues will be assessed.'

  2. Polarization signatures of airborne particulates

    NASA Astrophysics Data System (ADS)

    Raman, Prashant; Fuller, Kirk A.; Gregory, Don A.

    2013-07-01

    Exploratory research has been conducted with the aim of completely determining the polarization signatures of selected particulates as a function of wavelength. This may lead to a better understanding of the interaction between electromagnetic radiation and such materials, perhaps leading to the point detection of bio-aerosols present in the atmosphere. To this end, a polarimeter capable of measuring the complete Mueller matrix of highly scattering samples in transmission and reflection (with good spectral resolution from 300 to 1100 nm) has been developed. The polarization properties of Bacillus subtilis (surrogate for anthrax spore) are compared to ambient particulate matter species such as pollen, dust, and soot. Differentiating features in the polarization signatures of these samples have been identified, thus demonstrating the potential applicability of this technique for the detection of bio-aerosol in the ambient atmosphere.

  3. Progressive cone beam CT dose control in image-guided radiation therapy

    SciTech Connect

    Yan Hao; Cervino, Laura; Jiang, Steve B.; Jia Xun; Zhen Xin

    2013-06-15

    Purpose: Cone beam CT (CBCT) in image-guided radiotherapy (IGRT) offers a tremendous advantage for treatment guidance. The associated imaging dose is a clinical concern. One unique feature of CBCT-based IGRT is that the same patient is repeatedly scanned during a treatment course, and the contents of CBCT images at different fractions are similar. The authors propose a progressive dose control (PDC) scheme to utilize this temporal correlation for imaging dose reduction. Methods: A dynamic CBCT scan protocol, as opposed to the static one in the current clinical practice, is proposed to gradually reduce the imaging dose in each treatment fraction. The CBCT image from each fraction is processed by a prior-image based nonlocal means (PINLM) module to enhance its quality. The increasing amount of prior information from previous CBCT images prevents degradation of image quality due to the reduced imaging dose. Two proof-of-principle experiments have been conducted using measured phantom data and Monte Carlo simulated patient data with deformation. Results: In the measured phantom case, utilizing a prior image acquired at 0.4 mAs, PINLM is able to improve the image quality of a CBCT acquired at 0.2 mAs by reducing the noise level from 34.95 to 12.45 HU. In the synthetic patient case, acceptable image quality is maintained at four consecutive fractions with gradually decreasing exposure levels of 0.4, 0.1, 0.07, and 0.05 mAs. When compared with the standard low-dose protocol of 0.4 mAs for each fraction, an overall imaging dose reduction of more than 60% is achieved. Conclusions: PINLM-PDC is able to reduce CBCT imaging dose in IGRT utilizing the temporal correlations among the sequence of CBCT images while maintaining the quality.

  4. Nanometer scale exciton/photon dynamic spectrochemical imaging for DNA structure-activity relations and radiation signatures. Final progress report, December 24, 1993--December 23, 1996

    SciTech Connect

    Kopelman, R.

    1997-06-01

    This report is a summary of the work conducted during the period from December 24, 1993--December 23, 1996. Research is divided into five major areas: Near-field imaging of DNA clusters, chromosomes, etc.; Femtosecond near-field optical microscopy; Ultrafast and ultrasmall fluorescent chemical sensors; Feasibility study for nonlinear optics studies in the near-field; and Three-dimensional pH microprobing with a laser tweezer manipulated fluorescent particle. Brief summaries are given of each project and a series of photos are included.

  5. Uncertainty in hydrological signatures

    NASA Astrophysics Data System (ADS)

    Westerberg, I. K.; McMillan, H. K.

    2015-09-01

    Information about rainfall-runoff processes is essential for hydrological analyses, modelling and water-management applications. A hydrological, or diagnostic, signature quantifies such information from observed data as an index value. Signatures are widely used, e.g. for catchment classification, model calibration and change detection. Uncertainties in the observed data - including measurement inaccuracy and representativeness as well as errors relating to data management - propagate to the signature values and reduce their information content. Subjective choices in the calculation method are a further source of uncertainty. We review the uncertainties relevant to different signatures based on rainfall and flow data. We propose a generally applicable method to calculate these uncertainties based on Monte Carlo sampling and demonstrate it in two catchments for common signatures including rainfall-runoff thresholds, recession analysis and basic descriptive signatures of flow distribution and dynamics. Our intention is to contribute to awareness and knowledge of signature uncertainty, including typical sources, magnitude and methods for its assessment. We found that the uncertainties were often large (i.e. typical intervals of ±10-40 % relative uncertainty) and highly variable between signatures. There was greater uncertainty in signatures that use high-frequency responses, small data subsets, or subsets prone to measurement errors. There was lower uncertainty in signatures that use spatial or temporal averages. Some signatures were sensitive to particular uncertainty types such as rating-curve form. We found that signatures can be designed to be robust to some uncertainty sources. Signature uncertainties of the magnitudes we found have the potential to change the conclusions of hydrological and ecohydrological analyses, such as cross-catchment comparisons or inferences about dominant processes.

  6. Uncertainty in hydrological signatures

    NASA Astrophysics Data System (ADS)

    Westerberg, I. K.; McMillan, H. K.

    2015-04-01

    Information about rainfall-runoff processes is essential for hydrological analyses, modelling and water-management applications. A hydrological, or diagnostic, signature quantifies such information from observed data as an index value. Signatures are widely used, including for catchment classification, model calibration and change detection. Uncertainties in the observed data - including measurement inaccuracy and representativeness as well as errors relating to data management - propagate to the signature values and reduce their information content. Subjective choices in the calculation method are a further source of uncertainty. We review the uncertainties relevant to different signatures based on rainfall and flow data. We propose a generally applicable method to calculate these uncertainties based on Monte Carlo sampling and demonstrate it in two catchments for common signatures including rainfall-runoff thresholds, recession analysis and basic descriptive signatures of flow distribution and dynamics. Our intention is to contribute to awareness and knowledge of signature uncertainty, including typical sources, magnitude and methods for its assessment. We found that the uncertainties were often large (i.e. typical intervals of ±10-40% relative uncertainty) and highly variable between signatures. There was greater uncertainty in signatures that use high-frequency responses, small data subsets, or subsets prone to measurement errors. There was lower uncertainty in signatures that use spatial or temporal averages. Some signatures were sensitive to particular uncertainty types such as rating-curve form. We found that signatures can be designed to be robust to some uncertainty sources. Signature uncertainties of the magnitudes we found have the potential to change the conclusions of hydrological and ecohydrological analyses, such as cross-catchment comparisons or inferences about dominant processes.

  7. Modification of infrared signature of naval vessels

    NASA Astrophysics Data System (ADS)

    Milewski, S.; Dulski, R.; Kastek, M.; Trzaskawka, P.; Barela, J.; Firmanty, K.

    2012-06-01

    Every naval vessel can be detected and identified on the basis of its characteristics. The reduction of signature or matching it to the surrounding environment are one of the key tasks regarding survivability on a modern battlefield. The typical coatings applied on the outer surfaces of vessels are various kinds of paints. Their purpose is to protect the hull from aggressive sea environment and to provide camouflage in the visual spectrum as well as scatter and deflect microwave radiation. Apart from microwave and visual, infrared is most important spectral band used for detection purposes. In order to obtain effective protection in infrared the thermal signature of a vessel is required. It is determined on the basis of thermal contrast between a vessel itself and actual background and depends mostly on radiant properties of the hull. Such signature can be modified by altering apparent temperature values or the directions, in which the infrared radiation is emitted. The paper discusses selected methods of modification of vessel's infrared signature and effectiveness of infrared camouflage. Theoretical analyses were preceded by experimental measurements. The measurement-class infrared cameras and imaging spectroradiometers were used in order to determine the radiant exitance from different surface types. Experiments were conducted in selected conditions taking into account solar radiation and radiation reflected from elements of the surrounding scenery. Theoretical analysis took into account radiant angular properties of a vessel hull and attenuation of radiation after passing through the atmosphere. The study was performed in MWIR and LWIR ranges.

  8. Effects of Concurrent Topotecan and Radiation on 6-Month Progression-Free Survival in the Primary Treatment of Glioblastoma Multiforme

    SciTech Connect

    Grabenbauer, Gerhard G. Gerber, Klaus-Dieter; Ganslandt, Oliver; Richter, Andrea M.S.; Klautke, Gunther; Birkmann, Josef; Meyer, Martin

    2009-09-01

    Purpose: To report a prospective, randomized, Phase II trial of radiotherapy with and without topotecan for the treatment of glioblastoma. Patients and Methods: Inclusion criteria were histology of glioblastoma, age <60 years, and Eastern Cooperative Oncology Group status 0-2. Patients were stratified according to recursive partitioning analysis class, center, and enzyme-inducing antiepileptic medication. Magnetic resonance imaging scans, neurologic examinations, and quality of life assessments were done every 3 months. The primary endpoint was the progression-free survival rate at 6 months (6-m-PFS). This trial was designed as an exploratory, randomized, Phase II trial with an accrual of 140 patients to detect a difference of 15-20% in 6-m-PFS. An interim analysis was scheduled after 60 patients. Median follow-up was 14 months (range, 1-50 months). Results: The 6-m-PFS was 56% and 40% for patients with and without topotecan, respectively. This benefit disappeared within 2 months. Mean (range) progression-free survival time was 8 (5-10.9) months and 6.7 (4-9.5) months for patients with and without topotecan, respectively. The corresponding 2-year-overall survival rates were 28% vs. 22% (nonsignificant difference), and mean (range) survival time was 20.7 (13.9-27.5) months vs. 18.9 (13.5-24.4) months (nonsignificant difference). Conclusions: A slight but measurable increase of 16% was detected in 6-m-PFS for patients receiving topotecan with radiation as compared with patients having radiotherapy alone. These data might support further investigations into topotecan for the treatment of glioblastoma.

  9. A novel parameter, cell-cycle progression index, for radiation dose absorbed estimation in the premature chromosome condensation assay.

    PubMed

    Miura, Tomisato; Nakata, Akifumi; Kasai, Kosuke; Nakano, Manabu; Abe, Yu; Tsushima, Eiki; Ossetrova, Natalia I; Yoshida, Mitsuaki A; Blakely, William F

    2014-06-01

    The calyculin A-induced premature chromosome condensation (PCC) assay is a simple and useful method for assessing the cell-cycle distribution in cells, since calyculin A induces chromosome condensation in various phases of the cell cycle. In this study, a novel parameter, the cell-cycle progression index (CPI), in the PCC assay was validated as a novel biomarker for biodosimetry. Peripheral blood was drawn from healthy donors after informed consent was obtained. CPI was investigated using a human peripheral blood lymphocyte (PBL) ex vivo irradiation ((60)Co-gamma rays: ∼0.6 Gy min(-1), or X ray: 1.0 Gy min(-1); 0-10 Gy) model. The calyculin A-induced PCC assay was performed for chromosome preparation. PCC cells were divided into the following five categories according to cell-cycle stage: non-PCC, G1-PCC, S-PCC, G2/M-PCC and M/A-PCC cells. CPI was calculated as the ratio of G2/M-PCC cells to G1-PCC cells. The PCC-stage distribution varied markedly with irradiation doses. The G1-PCC cell fraction was significantly reduced, and the G2/M-PCC cell fraction increased, in 10-Gy-irradiated PBL after 48 h of culture. CPI levels were fitted to an exponential dose-response curve with gamma-ray irradiation [y = 0.6729 + 0.3934 exp(0.5685D), r = 1.0000, p < 0.0001] and X-ray irradiation [y = -0.3743 + 0.9744 exp(0.3321D), r = 0.9999, p < 0.0001]. There were no significant individual (p = 0.853) or gender effects (p = 0.951) on the CPI in the human peripheral blood ex vivo irradiation model. Furthermore, CPI measurements are rapid (< 15 min per case). These results suggest that the CPI is a useful screening tool for the assessment of radiation doses received ranging from 0 to 10 Gy in radiation exposure early after a radiation event, especially after a mass-casualty radiological incident. PMID:24743756

  10. Digital Signature Management.

    ERIC Educational Resources Information Center

    Hassler, Vesna; Biely, Helmut

    1999-01-01

    Describes the Digital Signature Project that was developed in Austria to establish an infrastructure for applying smart card-based digital signatures in banking and electronic-commerce applications. Discusses the need to conform to international standards, an international certification infrastructure, and security features for a public directory…

  11. Does MW Radiation Affect Gene Expression, Apoptotic Level, and Cell Cycle Progression of Human SH-SY5Y Neuroblastoma Cells?

    PubMed

    Kayhan, Handan; Esmekaya, Meric Arda; Saglam, Atiye Seda Yar; Tuysuz, Mehmed Zahid; Canseven, Ayşe Gulnihal; Yagci, Abdullah Munci; Seyhan, Nesrin

    2016-06-01

    Neuroblastoma (NB) is a cancer that occurs in sympathetic nervous system arising from neuroblasts and nerve tissue of the adrenal gland, neck, chest, or spinal cord. It is an embryonal malignancy and affects infants and children. In this study, we investigated the effects of microwave (MW) radiation on apoptotic activity, cell viability, and cell cycle progression in human SH-SY5Y NB cells which can give information about MW radiation effects on neural cells covering the period from the embryonic stages to infants. SH-SY5Y NB cells were exposed to 2.1 GHz W-CDMA modulated MW radiation for 24 h at a specific absorption rate of 0.491 W/kg. Control samples were in the same conditions with MW-exposed samples but they were not exposed to MW radiation. The apoptotic activity of cells was measured by Annexin-V-FITC and propidium iodide staining. Moreover, mRNA levels of proliferative and cell cycle proteins were determined by real-time RT-PCR. The change in cell cycle progression was observed by using CycleTest-Plus DNA reagent. No significant change was observed in apoptotic activity of MW-exposed cells compared to control cells. The mRNA levels of c-myc and cyclin D1 were significantly reduced in MW group (p < 0.05). The percentage of MW-exposed cells in G1 phase was significantly higher than the percentage of control cells in G1 phase. MW radiation caused cell cycle arrest in G1 phase. These results showed that 2.1 GHz W-CDMA modulated MW radiation did not cause apoptotic cell death but changed cell cycle progression. PMID:27260669

  12. A murine AP-endonuclease gene-targeted deficiency with post-implantation embryonic progression and ionizing radiation sensitivity.

    PubMed

    Ludwig, D L; MacInnes, M A; Takiguchi, Y; Purtymun, P E; Henrie, M; Flannery, M; Meneses, J; Pedersen, R A; Chen, D J

    1998-10-21

    Apurinic/apyrimidinic endonuclease (here designated APE/REF) carries out repair incision at abasic or single-strand break damages in mammals. This multifunctional protein also has putative role(s) as a cysteine 'reducing factor' (REF) in cell-stress transcriptional responses. To assess the significance of APE/REF for embryonic teratogenesis we constructed a more precisely targeted Ape/Ref-deficient genotype in mice. Ape/Ref gene replacement in ES cells eliminated the potential of APE/REF protein synthesis while retaining the Ape/Ref bi-directional promoter that avoided potential inactivation of an upstream gene. Chimeric animals crossed into Tac:N:NIHS-BC produced germline transmission. Homozygous null Ape/Ref-embryos exhibited successful implantation and nearly normal developmental progression until embryonic day 7.5 followed by morphogenetic failure and adsorption of embryos by day 9.5. We characterized the cellular events proceeding to embryonic lethality and examined ionizing radiation sensitivity of pre-implantation Ape/Ref-null embryos. After intermating of heterozygotes, Mendelian numbers of putative Ape/Ref-null progeny embryos at day 6.5 displayed a several-fold elevation of pycnotic, fragmenting cell nuclei within the embryo proper-the epiblast. Increased cell-nucleus degeneration occurred within epiblast cells while mitosis continued and before obvious morphogenetic disruption. Mitogenic response to epiblast cell death, if any, was ineffective for replacement of lost cells. Extra-embryonic yolk sac, a trophectoderm derived lineage retained normal appearance to day 9. Explanted homozygous Ape/Ref-null blastocysts displayed increased sensitivity to gamma-irradiation, most likely a manifestation of APE/REF incision defect. Our study establishes that this new Ape/Ref deficiency genotype is definitely capable of post-implantation developmental progression to the onset of gastrulation. Function(s) of APE/REF in base damage incision and also conceivably in

  13. Microvesicles as a Biomarker for Tumor Progression versus Treatment Effect in Radiation/Temozolomide-Treated Glioblastoma Patients

    PubMed Central

    Koch, Cameron J.; Lustig, Robert A.; Yang, Xiang-Yang; Jenkins, Walter T.; Wolf, Ronald L.; Martinez-Lage, Maria; Desai, Arati; Williams, Dewight; Evans, Sydney M.

    2014-01-01

    The standard of care for glioblastoma (GB) is surgery followed by concurrent radiation therapy (RT) and temozolomide (TMZ) and then adjuvant TMZ. This regime is associated with increased survival but also increased occurrence of equivocal imaging findings, e.g., tumor progression (TP) versus treatment effect (TE), which is also referred to as pseudoprogression (PsP). Equivocal findings make decisions regarding further treatment difficult and often delayed. Because none of the current imaging assays have proven sensitive and specific for differentiation of TP versus TE/PsP, we investigated whether blood-derived microvesicles (MVs) would be a relevant assay. METHODS: 2.8 ml of citrated blood was collected from patients with GB at the time of their RT simulation, at the end of chemoradiation therapy (CRT), and multiple times following treatment. MVs were collected following multiple centrifugations (300g, 2500g, and 15,000g). The pellet from the final spin was analyzed using flow cytometry. A diameter of approximately 300 nm or greater and Pacific Blue–labeled Annexin V positivity were used to identify the MVs reported herein. RESULTS: We analyzed 19 blood samples from 11 patients with GB. MV counts in the patients with stable disease or TE/PsP were significantly lower than patients who developed TP (P = .014). CONCLUSION: These preliminary data suggest that blood analysis for MVs from GB patients receiving CRT may be useful to distinguish TE/PsP from TP. MVs may add clarity to standard imaging for decision making in patients with equivocal imaging findings. PMID:25500085

  14. Traceable Ring Signature

    NASA Astrophysics Data System (ADS)

    Fujisaki, Eiichiro; Suzuki, Koutarou

    The ring signature allows a signer to leak secrets anonymously, without the risk of identity escrow. At the same time, the ring signature provides great flexibility: No group manager, no special setup, and the dynamics of group choice. The ring signature is, however, vulnerable to malicious or irresponsible signers in some applications, because of its anonymity. In this paper, we propose a traceable ring signature scheme. A traceable ring scheme is a ring signature except that it can restrict “excessive” anonymity. The traceable ring signature has a tag that consists of a list of ring members and an issue that refers to, for instance, a social affair or an election. A ring member can make any signed but anonymous opinion regarding the issue, but only once (per tag). If the member submits another signed opinion, possibly pretending to be another person who supports the first opinion, the identity of the member is immediately revealed. If the member submits the same opinion, for instance, voting “yes” regarding the same issue twice, everyone can see that these two are linked. The traceable ring signature can suit to many applications, such as an anonymous voting on a BBS. We formalize the security definitions for this primitive and show an efficient and simple construction in the random oracle model.

  15. UV Signature Mutations †

    PubMed Central

    2014-01-01

    Sequencing complete tumor genomes and exomes has sparked the cancer field's interest in mutation signatures for identifying the tumor's carcinogen. This review and meta-analysis discusses signatures and their proper use. We first distinguish between a mutagen's canonical mutations – deviations from a random distribution of base changes to create a pattern typical of that mutagen – and the subset of signature mutations, which are unique to that mutagen and permit inference backward from mutations to mutagen. To verify UV signature mutations, we assembled literature datasets on cells exposed to UVC, UVB, UVA, or solar simulator light (SSL) and tested canonical UV mutation features as criteria for clustering datasets. A confirmed UV signature was: ≥60% of mutations are C→T at a dipyrimidine site, with ≥5% CC→TT. Other canonical features such as a bias for mutations on the non-transcribed strand or at the 3' pyrimidine had limited application. The most robust classifier combined these features with criteria for the rarity of non-UV canonical mutations. In addition, several signatures proposed for specific UV wavelengths were limited to specific genes or species; non-signature mutations induced by UV may cause melanoma BRAF mutations; and the mutagen for sunlight-related skin neoplasms may vary between continents. PMID:25354245

  16. An archaeal genomic signature

    NASA Technical Reports Server (NTRS)

    Graham, D. E.; Overbeek, R.; Olsen, G. J.; Woese, C. R.

    2000-01-01

    Comparisons of complete genome sequences allow the most objective and comprehensive descriptions possible of a lineage's evolution. This communication uses the completed genomes from four major euryarchaeal taxa to define a genomic signature for the Euryarchaeota and, by extension, the Archaea as a whole. The signature is defined in terms of the set of protein-encoding genes found in at least two diverse members of the euryarchaeal taxa that function uniquely within the Archaea; most signature proteins have no recognizable bacterial or eukaryal homologs. By this definition, 351 clusters of signature proteins have been identified. Functions of most proteins in this signature set are currently unknown. At least 70% of the clusters that contain proteins from all the euryarchaeal genomes also have crenarchaeal homologs. This conservative set, which appears refractory to horizontal gene transfer to the Bacteria or the Eukarya, would seem to reflect the significant innovations that were unique and fundamental to the archaeal "design fabric." Genomic protein signature analysis methods may be extended to characterize the evolution of any phylogenetically defined lineage. The complete set of protein clusters for the archaeal genomic signature is presented as supplementary material (see the PNAS web site, www.pnas.org).

  17. Determination of local radiative properties in coal-fired flames. Technical progress report, September 15, 1987--September 15, 1988

    SciTech Connect

    Menguec, M.P.; Agarwal, B.; Bush, M.; Dsa, D.; Subramaniam, S.

    1988-12-31

    Recently, an extensive, in-depth review of the modeling of radiation heat transfer in combustion chambers has been prepared (Viskanta and Menguc, 1987); therefore, there is no need to repeat that material here. It is already known that the most important missing link in the prediction of radiation heat transfer in combustion systems is the lack of detailed information about the optical and physical properties of combustion products (Viskanta and Menguc, 1987). The purpose of this research is to determine the radiative properties of coal particles. Considering the uncertainty in the fundamental optical and physical properties of coal particles, such as complex index of refraction, size, size distribution, and shape, it is difficult to predict the radiative properties of particles using available analytical methods, such as Lorenz-Mie theory. For a better understanding of radiation and radiation/combustion or radiation/turbulence interactions, it is preferable to determine the radiative properties in situ.

  18. Signature extension studies

    NASA Technical Reports Server (NTRS)

    Vincent, R. K.; Thomas, G. S.; Nalepka, R. F.

    1974-01-01

    The importance of specific spectral regions to signature extension is explored. In the recent past, the signature extension task was focused on the development of new techniques. Tested techniques are now used to investigate this spectral aspect of the large area survey. Sets of channels were sought which, for a given technique, were the least affected by several sources of variation over four data sets and yet provided good object class separation on each individual data set. Using sets of channels determined as part of this study, signature extension was accomplished between data sets collected over a six-day period and over a range of about 400 kilometers.

  19. Are there molecular signatures?

    SciTech Connect

    Bennett, W.P.

    1995-10-01

    This report describes molecular signatures and mutational spectrum analysis. The mutation spectrum is defined as the type and location of DNA base change. There are currently about five well documented cases. Mutations and radon-associated tumors are discussed.

  20. Meteor signature interpretation

    SciTech Connect

    Canavan, G.H.

    1997-01-01

    Meteor signatures contain information about the constituents of space debris and present potential false alarms to early warnings systems. Better models could both extract the maximum scientific information possible and reduce their danger. Accurate predictions can be produced by models of modest complexity, which can be inverted to predict the sizes, compositions, and trajectories of object from their signatures for most objects of interest and concern.

  1. Radiative Magnetic Reconnection in Astrophysics

    NASA Astrophysics Data System (ADS)

    Uzdensky, D. A.

    In this chapter we review a new and rapidly growing area of research in high-energy plasma astrophysics—radiative magnetic reconnection, defined here as a regime of reconnection where radiation reaction has an important influence on the reconnection dynamics, energetics, and/or nonthermal particle acceleration. This influence be may be manifested via a variety of radiative effects that are critical in many high-energy astrophysical applications. The most notable radiative effects in astrophysical reconnection include radiation-reaction limits on particle acceleration, radiative cooling, radiative resistivity, braking of reconnection outflows by radiation drag, radiation pressure, viscosity, and even pair creation at highest energy densities. The self-consistent inclusion of these effects into magnetic reconnection theory and modeling sometimes calls for serious modifications to our overall theoretical approach to the problem. In addition, prompt reconnection-powered radiation often represents our only observational diagnostic tool available for studying remote astrophysical systems; this underscores the importance of developing predictive modeling capabilities to connect the underlying physical conditions in a reconnecting system to observable radiative signatures. This chapter presents an overview of our recent theoretical progress in developing basic physical understanding of radiative magnetic reconnection, with a special emphasis on astrophysically most important radiation mechanisms like synchrotron, curvature, and inverse-Compton. The chapter also offers a broad review of key high-energy astrophysical applications of radiative reconnection, illustrated by multiple examples such as: pulsar wind nebulae, pulsar magnetospheres, black-hole accretion-disk coronae and hot accretion flows in X-ray Binaries and Active Galactic Nuclei and their relativistic jets, magnetospheres of magnetars, and Gamma-Ray Bursts. Finally, this chapter discusses the most critical

  2. UV signature mutations.

    PubMed

    Brash, Douglas E

    2015-01-01

    Sequencing complete tumor genomes and exomes has sparked the cancer field's interest in mutation signatures for identifying the tumor's carcinogen. This review and meta-analysis discusses signatures and their proper use. We first distinguish between a mutagen's canonical mutations—deviations from a random distribution of base changes to create a pattern typical of that mutagen—and the subset of signature mutations, which are unique to that mutagen and permit inference backward from mutations to mutagen. To verify UV signature mutations, we assembled literature datasets on cells exposed to UVC, UVB, UVA, or solar simulator light (SSL) and tested canonical UV mutation features as criteria for clustering datasets. A confirmed UV signature was: ≥60% of mutations are C→T at a dipyrimidine site, with ≥5% CC→TT. Other canonical features such as a bias for mutations on the nontranscribed strand or at the 3' pyrimidine had limited application. The most robust classifier combined these features with criteria for the rarity of non-UV canonical mutations. In addition, several signatures proposed for specific UV wavelengths were limited to specific genes or species; UV's nonsignature mutations may cause melanoma BRAF mutations; and the mutagen for sunlight-related skin neoplasms may vary between continents. PMID:25354245

  3. Stability of a liquid-film space radiator with internal electrostatic fields. Progress report, October 1, 1991--September 30, 1992

    SciTech Connect

    Bankoff, S.G.; Miksis, M.J.

    1992-04-01

    A new concept in light-weight space radiators has been introduced by Kim, Miksis and Bankoff, consisting of a pumped-loop membrane radiator in which leakage of coolant from a puncture, due to micrometeorite or space debris impact, is prevented by the application of an internal electrostatic field. For nuclear space power, the coolant is generally a liquid metal, such as lithium, flowing as a thin film along the interior walls of the hollow radiator. A lightweight fully-modular radiator design is proposed, which is calculated to weight less than 1 kg/m{sup 2}. The feature which makes this thin-membrane radiator practical is the internal electrostatic field system, which can stop radiator leaks from punctures, sudden accelerations or accidental tears.

  4. Radiation

    NASA Video Gallery

    Outside the protective cocoon of Earth's atmosphere, the universe is full of harmful radiation. Astronauts who live and work in space are exposed not only to ultraviolet rays but also to space radi...

  5. Invisibly Sanitizable Signature without Pairings

    NASA Astrophysics Data System (ADS)

    Yum, Dae Hyun; Lee, Pil Joong

    Sanitizable signatures allow sanitizers to delete some pre-determined parts of a signed document without invalidating the signature. While ordinary sanitizable signatures allow verifiers to know how many subdocuments have been sanitized, invisibly sanitizable signatures do not leave any clue to the sanitized subdocuments; verifiers do not know whether or not sanitizing has been performed. Previous invisibly sanitizable signature scheme was constructed based on aggregate signature with pairings. In this article, we present the first invisibly sanitizable signature without using pairings. Our proposed scheme is secure under the RSA assumption.

  6. The Influence of Radiation in Altering the Incidence of Mutations in Drosophila. Progress Report on the Past Twelve Months and Renewal Proposal for the Period September 15, 1960 to September 14, 1961

    DOE R&D Accomplishments Database

    Muller, H. J.

    1960-05-31

    Progress is reported in studies on the effects of radiation on the incidence of mutations in Drosophila. Results are summarized and the findings are interpreted. A list is included of papers published during the period. (C.H.)

  7. Extragalactic cosmic rays and their signatures

    NASA Astrophysics Data System (ADS)

    Berezinsky, V.

    2014-01-01

    The signatures of UHE proton propagation through CMB radiation are pair-production dip and GZK cutoff. The visible manifestations of these two spectral features are ankle, which is intrinsic part of the dip, beginning of GZK cutoff in the differential spectrum and E in integral spectrum. Observed practically in all experiments since 1963, the ankle is usually interpreted as a feature caused by transition from galactic to extragalactic cosmic rays. Using the mass composition measured by HiRes, Telescope Array and Auger detectors at energy (1-3) EeV, calculated anisotropy of galactic cosmic rays at these energies, and the elongation curves we strongly argue against the interpretation of the ankle given above. The transition must occur at lower energy, most probably at the second knee as the dip model predicts. The other prediction of the dip model, the shape of the dip, is well confirmed by HiRes, Telescope Array (TA), AGASA and Yakutsk detectors, and, after recalibration of energies, by Auger detector. Predicted beginning of GZK cutoff and E agree well with HiRes and TA data. However, directly measured mass composition remains a puzzle. While HiRes and TA detectors observe the proton-dominated mass composition, as required by the dip model, the data of Auger detector strongly evidence for nuclei mass composition becoming progressively heavier at energy higher than 4 EeV and reaching Iron at energy about 35 EeV. The Auger-based scenario is consistent with another interpretation of the ankle at energy Ea≈4 EeV as transition from extragalactic protons to extragalactic nuclei. The heavy-nuclei dominance at higher energies may be provided by low-energy of acceleration for protons Epmax∼4 EeV and rigidity-dependent EAmax=ZEpmax for nuclei. The highest energy suppression may be explained as nuclei-photodisintegration cutoff.

  8. NRC TLD Direct Radiation Monitoring Network. Volume 15, No. 4: Quarterly progress report, October--December 1995

    SciTech Connect

    Struckmeyer, R.

    1996-03-01

    This report presents the results of the NRC Direct Radiation Monitoring Network for the fourth quarter of 1995. It provides the ambient radiation levels measured in the vicinity of 75 sites throughout the United States. In addition, it describes the equipment used, monitoring station selection criteria, characterization of the dosimeter response, calibration procedures, statistical methods, intercomparison, and quality assurance program.

  9. Progress Toward Electrostatic Radiation Shielding of Interplanetary Spacecraft: Strategies, Concepts and Technical Challenges of Human Exploration Beyond Low Earth Orbit

    NASA Technical Reports Server (NTRS)

    Metzger, Philip T.; Lane, John E.; Youngquist, Robert C.

    2004-01-01

    The radiation problem is a serious obstacle to solar system exploration. Electrostatic shielding was previously dismissed as unworkable. This was based on the false assumption that radial symmetry is needed to provide isotropic protection. KSC recently demonstrated the feasibility of asymmetric, multipole electrostatic shielding. Combined with passive shielding it might solve the radiation problem

  10. Studies of the repair of radiation-induced genetic damage in Drosophila. Annual progress report, February 1-July 1, 1983

    SciTech Connect

    Not Available

    1983-01-01

    Research progress is reported in the following areas: (1) characterization of a photo-repair deficient mutant in Drosophila; (2) the role of poly(ADPR)polymerase in Drosophila repair; and (3) service functions. (ACR)

  11. Practical quantum digital signature

    NASA Astrophysics Data System (ADS)

    Yin, Hua-Lei; Fu, Yao; Chen, Zeng-Bing

    2016-03-01

    Guaranteeing nonrepudiation, unforgeability as well as transferability of a signature is one of the most vital safeguards in today's e-commerce era. Based on fundamental laws of quantum physics, quantum digital signature (QDS) aims to provide information-theoretic security for this cryptographic task. However, up to date, the previously proposed QDS protocols are impractical due to various challenging problems and most importantly, the requirement of authenticated (secure) quantum channels between participants. Here, we present the first quantum digital signature protocol that removes the assumption of authenticated quantum channels while remaining secure against the collective attacks. Besides, our QDS protocol can be practically implemented over more than 100 km under current mature technology as used in quantum key distribution.

  12. Uncertainty in hydrological signatures

    NASA Astrophysics Data System (ADS)

    McMillan, Hilary; Westerberg, Ida

    2015-04-01

    Information that summarises the hydrological behaviour or flow regime of a catchment is essential for comparing responses of different catchments to understand catchment organisation and similarity, and for many other modelling and water-management applications. Such information types derived as an index value from observed data are known as hydrological signatures, and can include descriptors of high flows (e.g. mean annual flood), low flows (e.g. mean annual low flow, recession shape), the flow variability, flow duration curve, and runoff ratio. Because the hydrological signatures are calculated from observed data such as rainfall and flow records, they are affected by uncertainty in those data. Subjective choices in the method used to calculate the signatures create a further source of uncertainty. Uncertainties in the signatures may affect our ability to compare different locations, to detect changes, or to compare future water resource management scenarios. The aim of this study was to contribute to the hydrological community's awareness and knowledge of data uncertainty in hydrological signatures, including typical sources, magnitude and methods for its assessment. We proposed a generally applicable method to calculate these uncertainties based on Monte Carlo sampling and demonstrated it for a variety of commonly used signatures. The study was made for two data rich catchments, the 50 km2 Mahurangi catchment in New Zealand and the 135 km2 Brue catchment in the UK. For rainfall data the uncertainty sources included point measurement uncertainty, the number of gauges used in calculation of the catchment spatial average, and uncertainties relating to lack of quality control. For flow data the uncertainty sources included uncertainties in stage/discharge measurement and in the approximation of the true stage-discharge relation by a rating curve. The resulting uncertainties were compared across the different signatures and catchments, to quantify uncertainty

  13. Current signature sensor

    NASA Technical Reports Server (NTRS)

    Perotti, Jose M. (Inventor); Lucena, Angel (Inventor); Ihlefeld, Curtis (Inventor); Burns, Bradley (Inventor); Bassignani, Karin E. (Inventor)

    2005-01-01

    A solenoid health monitoring system uses a signal conditioner and controller assembly in one embodiment that includes analog circuitry and a DSP controller. The analog circuitry provides signal conditioning to the low-level raw signal coming from a signal acquisition assembly. Software running in a DSP analyzes the incoming data (recorded current signature) and determines the state of the solenoid whether it is energized, de-energized, or in a transitioning state. In one embodiment, the software identifies key features in the current signature during the transition phase and is able to determine the health of the solenoid.

  14. Current Signature Sensor

    NASA Technical Reports Server (NTRS)

    Perotti, Jose M. (Inventor); Lucena, Angel (Inventor); Ihlefeld, Curtis (Inventor); Burns, Bradley (Inventor); Bassignani, Mario (Inventor); Bassignani, Karin E. (Inventor)

    2005-01-01

    A solenoid health monitoring system uses a signal conditioner and controller assembly in one embodiment that includes analog circuitry and a DSP controller. The analog circuitry provides signal conditioning to the low-level raw signal coming from a signal acquisition assembly. Software running in a DSP analyzes the incoming data (recorded current signature) and determines the state of the solenoid whether it is energized, de-energized, or in a transitioning state. In one embodiment, the software identifies key features in the current signature during the transition phase and is able to determine the health of the solenoid.

  15. Progress Report for Annex II--Assessment of Solar Radiation Resources in Saudi Arabia 1993-1997

    SciTech Connect

    Al-Amoudi, Anmed; Alawaji, Saleh H.; Cornwall, Chris; Mahfoodh, Mohammed bin; Marion, Bill; Maxwell, Eugene L.; Wilcox, Stephen M.

    1999-08-20

    In 1987, the United States Department of Energy (DOE) and the King Abdulaziz City for Science and Technology (KACST) signed a five-year Agreement for Cooperation in the Field of Renewable Energy Research and Development (R and D), which has been extended to 2000. Tasks include: (1) upgrade solar radiation measurements in Saudi Arabia; (2) assemble a database of concurrent solar radiation, satellite (METEOSAT), and meteorological data; (3) adapt NREL models and other software for Saudi Arabia; (4) develop procedures, algorithms, and software to estimate solar irradiance; and (5) prepare a grid of solar radiation data for preparing maps and atlases and estimating solar radiation resources and solar energy system performances at locations in Saudi Arabia.

  16. [Development and recommendations in the area of ionizing and nonionizing radiations]. Progress report, 1 September 1991--30 April 1992

    SciTech Connect

    Not Available

    1992-09-01

    This report briefly describes seven publications produced in 1991--1992 under the auspices of the National Council on Radiation Protection and Measurements. In addition current status of additional publications in preparation are outlined.

  17. Development of rotating shadowband spectral radiometers and GCM radiation code test data sets in support of ARM. Technical progress report

    SciTech Connect

    Michalsky, J.; Harrison, L.

    1992-03-17

    Two tasks are included in the second year of this project. One task continues the collection of high quality data sets for the testing of radiation codes within climate models. The other task involves the development of accurate spectral instruments for the measurement of shortwave radiation. A third task was completed in the second half of the first year of the project and will be briefly summarized.

  18. Nanodosimetry and nanodosimetric-based models of radiation action for radon alpha particles. Progress report, July 1990--June 1992

    SciTech Connect

    Zaider, M.

    1992-12-31

    We report on a theory for describing the biological effects of ionizing radiation in particular radon {alpha} particles. Behind this approach is the recognition that biological effects such as chromosome aberrations, cellular transformation, cellular inactivation, etc, are the result of a hierarchic sequence of radiation effects. We indicate how to treat each of the individual processes in this sequence, and also how to relate one effect to the hierarchically superior one.

  19. Elucidation of changes in molecular signalling leading to increased cellular transformation in oncogenically progressed human bronchial epithelial cells exposed to radiations of increasing LET.

    PubMed

    Ding, Liang-Hao; Park, Seongmi; Xie, Yang; Girard, Luc; Minna, John D; Story, Michael D

    2015-09-01

    The early transcriptional response and subsequent induction of anchorage-independent growth after exposure to particles of high Z and energy (HZE) as well as γ-rays were examined in human bronchial epithelial cells (HBEC3KT) immortalised without viral oncogenes and an isogenic variant cell line whose p53 expression was suppressed but that expressed an active mutant K-RAS(V12) (HBEC3KT-P53KRAS). Cell survival following irradiation showed that HBEC3KT-P53KRAS cells were more radioresistant than HBEC3KT cells irrespective of the radiation species. In addition, radiation enhanced the ability of the surviving HBEC3KT-P53RAS cells but not the surviving HBEC3KT cells to grow in anchorage-independent fashion (soft agar colony formation). HZE particle irradiation was far more efficient than γ-rays at rendering HBEC3KT-P53RAS cells permissive for soft agar growth. Gene expression profiles after radiation showed that the molecular response to radiation for HBEC3KT-P53RAS, similar to that for HBEC3KT cells, varies with radiation quality. Several pathways associated with anchorage independent growth, including the HIF-1α, mTOR, IGF-1, RhoA and ERK/MAPK pathways, were over-represented in the irradiated HBEC3KT-P53RAS cells compared to parental HBEC3KT cells. These results suggest that oncogenically progressed human lung epithelial cells are at greater risk for cellular transformation and carcinogenic risk after ionising radiation, but particularly so after HZE radiations. These results have implication for: (i) terrestrial radiation and suggests the possibility of enhanced carcinogenic risk from diagnostic CT screens used for early lung cancer detection; (ii) enhanced carcinogenic risk from heavy particles used in radiotherapy; and (iii) for space radiation, raising the possibility that astronauts harbouring epithelial regions of dysplasia or hyperplasia within the lung that contain oncogenic changes, may have a greater risk for lung cancers based upon their exposure to heavy

  20. Elucidation of changes in molecular signalling leading to increased cellular transformation in oncogenically progressed human bronchial epithelial cells exposed to radiations of increasing LET

    PubMed Central

    Ding, Liang-Hao; Park, Seongmi; Xie, Yang; Girard, Luc; Minna, John D.; Story, Michael D.

    2015-01-01

    The early transcriptional response and subsequent induction of anchorage-independent growth after exposure to particles of high Z and energy (HZE) as well as γ-rays were examined in human bronchial epithelial cells (HBEC3KT) immortalised without viral oncogenes and an isogenic variant cell line whose p53 expression was suppressed but that expressed an active mutant K-RASV12 (HBEC3KT-P53KRAS). Cell survival following irradiation showed that HBEC3KT-P53KRAS cells were more radioresistant than HBEC3KT cells irrespective of the radiation species. In addition, radiation enhanced the ability of the surviving HBEC3KT-P53RAS cells but not the surviving HBEC3KT cells to grow in anchorage-independent fashion (soft agar colony formation). HZE particle irradiation was far more efficient than γ-rays at rendering HBEC3KT-P53RAS cells permissive for soft agar growth. Gene expression profiles after radiation showed that the molecular response to radiation for HBEC3KT-P53RAS, similar to that for HBEC3KT cells, varies with radiation quality. Several pathways associated with anchorage independent growth, including the HIF-1α, mTOR, IGF-1, RhoA and ERK/MAPK pathways, were over-represented in the irradiated HBEC3KT-P53RAS cells compared to parental HBEC3KT cells. These results suggest that oncogenically progressed human lung epithelial cells are at greater risk for cellular transformation and carcinogenic risk after ionising radiation, but particularly so after HZE radiations. These results have implication for: (i) terrestrial radiation and suggests the possibility of enhanced carcinogenic risk from diagnostic CT screens used for early lung cancer detection; (ii) enhanced carcinogenic risk from heavy particles used in radiotherapy; and (iii) for space radiation, raising the possibility that astronauts harbouring epithelial regions of dysplasia or hyperplasia within the lung that contain oncogenic changes, may have a greater risk for lung cancers based upon their exposure to heavy

  1. Time-Dependent Delayed Signatures from Energetic Photon Interrogations

    SciTech Connect

    Daren R. Norman; James L. Jones; Brandon W. Blackburn; Kevin J. Haskell; James T. Johnson; Scott M. Watson; Alan W. Hunt; Randy Spaulding; Frank Harmon

    2007-08-01

    Pulsed photonuclear interrogation environments generated by 8–24 MeV electron linac are rich with time-dependent, material-specific, radiation signatures. Nitrogen-based explosives and nuclear materials can be detected by exploiting these signatures in different delayed-time regions. Numerical and experimental results presented in this paper show the unique time and energy dependence of these signatures. It is shown that appropriate delayed-time windows are essential to acquire material-specific signatures in pulsed photonuclear assessment environments. These developments demonstrate that pulsed, high-energy, photon-inspection environments can be exploited for time-dependent, material-specific signatures through the proper operation of specialized detectors and detection methods.

  2. Time-Dependent Delayed Signatures from Energetic Photon Interrogations

    SciTech Connect

    Daren R. Norman; James L. Jones; Brandon W. Blackburn; Kevin J. Haskell; James T. Johnson; Scott M. Watson; Alan W. Hunt; Randy Spaulding; Frank Harmon

    2007-08-01

    Pulsed photonuclear interrogation environments generated by 8–24 MeV electron linac are rich with time-dependent, material-specific, radiation signatures. Nitrogen-based explosives and nuclear materials can be detected by exploiting these signatures in different delayed-time regions. Numerical and experimental results presented in this paper show the unique time and energy dependence of these signatures. It is shown that appropriate delayed-time windows are essential to acquire material-specific signatures in the pulsed photonuclear assessment (PPA) environments. These developments demonstrate that pulsed, high-energy, photon- inspection environments can be exploited for time-dependent, material-specific signatures through the proper operation of specialized detectors and detection methods.

  3. A Signature Style

    ERIC Educational Resources Information Center

    Smiles, Robin V.

    2005-01-01

    This article discusses Dr. Amalia Amaki and her approach to art as her signature style by turning everyday items into fine art. Amaki is an assistant professor of art, art history, and Black American studies at the University of Delaware. She loves taking unexpected an object and redefining it in the context of art--like a button, a fan, a faded…

  4. Radiation forces and torque on a rigid elliptical cylinder in acoustical plane progressive and (quasi)standing waves with arbitrary incidence

    NASA Astrophysics Data System (ADS)

    Mitri, F. G.

    2016-07-01

    This paper presents two key contributions; the first concerns the development of analytical expressions for the axial and transverse acoustic radiation forces exerted on a 2D rigid elliptical cylinder placed in the field of plane progressive, quasi-standing, or standing waves with arbitrary incidence. The second emphasis is on the acoustic radiation torque per length. The rigid elliptical cylinder case is important to be considered as a first-order approximation of the behavior of a cylindrical fluid column trapped in air because of the significant acoustic impedance mismatch at the particle boundary. Based on the rigorous partial-wave series expansion method in cylindrical coordinates, non-dimensional acoustic radiation force and torque functions are derived and defined in terms of the scattering coefficients of the elliptic cylinder. A coupled system of linear equations is obtained after applying the Neumann boundary condition for an immovable surface in a non-viscous fluid and solved numerically by matrix inversion after performing a single numerical integration procedure. Computational results for the non-dimensional force components and torque, showing the transition from the progressive to the (equi-amplitude) standing wave behavior, are performed with particular emphasis on the aspect ratio a/b, where a and b are the semi-axes of the ellipse, the dimensionless size parameter, as well as the angle of incidence ranging from end-on to broadside incidence. The results show that the elliptical geometry has a direct influence on the radiation force and torque, so that the standard theory for circular cylinders (at normal incidence) leads to significant miscalculations when the cylinder cross section becomes non-circular. Moreover, the elliptical cylinder experiences, in addition to the acoustic radiation force, a radiation torque that vanishes for the circular cylinder case. The application of the formalism presented here may be extended to other 2D surfaces of

  5. Radiation/turbulence interactions in pulverized-coal flames. Second year technical progress report, September 30, 1994--September 30, 1995

    SciTech Connect

    Menguec, M.P.; McDonough, J.M.; Manickavsagam, S.; Mukerji, S.; Wang, D.; Ghosal, S.; Swabb, S.

    1995-12-31

    Our goal in this project is to investigate the interaction of radiation and turbulence in coalfired laboratory scale flames and attempt to determine the boundaries of the ``uncertainty domain`` in Figure 3 more rigorously. We have three distinct objectives: (1) To determine from experiments the effect of turbulent fluctuations on the devolatilization/pyrolysis of coal particles and soot yield, and to measure the change in the ``effective`` radiative properties of particulates due to turbulence interactions; (2) To perform local small-scale simulations to investigate the radiation-turbulence interactions in coal-fired flames starting from first principles; and (3) To develop a thorough and rigorous, but computationally practical, turbulence model for coal flames, starting from the experimental observations and small scale simulations.

  6. Recent progress in defining mechanisms and potential targets for prevention of normal tissue injury after radiation therapy

    SciTech Connect

    Anscher, Mitchell S. . E-mail: anscher@radonc.duke.edu; Chen, Liguang; Rabbani, Zahid; Kang Song; Larrier, Nicole; Huang Hong; Samulski, Thaddeus V.; Dewhirst, Mark W.; Brizel, David M.; Folz, Rodney J.; Vujaskovic, Zeljko

    2005-05-01

    The ability to optimize treatments for cancer on the basis of relative risks for normal tissue injury has important implications in oncology, because higher doses of radiation might, in some diseases, improve both local control and survival. To achieve this goal, a thorough understanding of the molecular mechanisms responsible for radiation-induced toxicity will be essential. Recent research has demonstrated that ionizing radiation triggers a series of genetic and molecular events, which might lead to chronic persistent alterations in the microenvironment and an aberrant wound-healing response. Disrupted epithelial-stromal cell communication might also be important. With the application of a better understanding of fundamental biology to clinical practice, new approaches to treating and preventing normal tissue injury can focus on correcting these disturbed molecular processes.

  7. Terahertz spectral signatures of explosive materials and precursors

    NASA Astrophysics Data System (ADS)

    Ball, Christopher D.; Ronningen, T. J.; Oesterling, Lee C.

    2009-05-01

    Terahertz (THz) spectral signatures have been measured for a variety of explosive materials and precursors. These signatures were measured by THz Time Domain Spectroscopy, using ultrashort pulsed lasers coupled with electro-optic materials to generate and detect THz radiation. Transmission and reflection spectra were measured across a frequency range from 0.2 to 2.5 THz for solid and liquid materials. These spectra are reported in terms of index of refraction and absorption coefficient, both of which can be calculated from transmission or reflection data. The value of THz spectral signatures for the development of future explosives sensing systems is discussed.

  8. Ultrawideband SAR signature investigations based on electromagnetic models and measurements

    NASA Astrophysics Data System (ADS)

    Lee, Check F.; Binder, Bradley T.

    1995-06-01

    The performance of an electric field integral equation (EFIE) model is discussed in the context of target detection and classification. This EFIE model, which is a modified version of the Finite Element Radiation model developed at MIT Lincoln Laboratory, was used to simulate VHF SAR signatures of ground targets. These SAR signatures were studied and compared with signatures generated from data colelcted by the CARABAS sensor during a 1993 Foliage Penetration Radar experiment. It was found that the EFIE model can provide adequate RCS values and distributions for gound target detection studies. It was also found that the simulated images have reasonable spatial appearance and may be useful for ground target classification studies.

  9. Effect of radiation-sensitive mutations and mutagens/carcinogens on bacterial recombination and mutagenesis. Progress report

    SciTech Connect

    Not Available

    1982-01-01

    Progress is reported in the following research areas: (1) mutagen assay using Escherichia coli was investigated; (2) a recombination assay has been developed with use of an E. coli partial diploid; (3) the Ames test has been expanded to include Salmonella strains with excision repair capability; and (4) the expanded Ames test was used to test the mutagenicity of various antineoplastic drugs. (ACR)

  10. Progress in Space Weather Modeling and Observations Needed to Improve the Operational NAIRAS Model Aircraft Radiation Exposure Predictions

    NASA Astrophysics Data System (ADS)

    Mertens, C. J.; Kress, B. T.; Wiltberger, M. J.; Tobiska, W.; Xu, X.

    2011-12-01

    The Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) is a prototype operational model for predicting commercial aircraft radiation exposure from galactic and solar cosmic rays. NAIRAS predictions are currently streaming live from the project's public website, and the exposure rate nowcast is also available on the SpaceWx smartphone app for iPhone, IPad, and Android. Cosmic rays are the primary source of human exposure to high linear energy transfer radiation at aircraft altitudes, which increases the risk of cancer and other adverse health effects. Thus, the NAIRAS model addresses an important national need with broad societal, public health and economic benefits. The processes responsible for the variability in the solar wind, interplanetary magnetic field, solar energetic particle spectrum, and the dynamical response of the magnetosphere to these space environment inputs, strongly influence the composition and energy distribution of the atmospheric ionizing radiation field. During the development of the NAIRAS model, new science questions were identified that must be addressed in order to obtain a more reliable and robust operational model of atmospheric radiation exposure. Addressing these science questions require improvements in both space weather modeling and observations. The focus of this talk is to present these science questions, the proposed methodologies for addressing these science questions, and the anticipated improvements to the operational predictions of atmospheric radiation exposure. The overarching goal of this work is to provide a decision support tool for the aviation industry that will enable an optimal balance to be achieved between minimizing health risks to passengers and aircrew while simultaneously minimizing costs to the airline companies.

  11. Hyperspectral signature analysis of skin parameters

    NASA Astrophysics Data System (ADS)

    Vyas, Saurabh; Banerjee, Amit; Garza, Luis; Kang, Sewon; Burlina, Philippe

    2013-02-01

    The temporal analysis of changes in biological skin parameters, including melanosome concentration, collagen concentration and blood oxygenation, may serve as a valuable tool in diagnosing the progression of malignant skin cancers and in understanding the pathophysiology of cancerous tumors. Quantitative knowledge of these parameters can also be useful in applications such as wound assessment, and point-of-care diagnostics, amongst others. We propose an approach to estimate in vivo skin parameters using a forward computational model based on Kubelka-Munk theory and the Fresnel Equations. We use this model to map the skin parameters to their corresponding hyperspectral signature. We then use machine learning based regression to develop an inverse map from hyperspectral signatures to skin parameters. In particular, we employ support vector machine based regression to estimate the in vivo skin parameters given their corresponding hyperspectral signature. We build on our work from SPIE 2012, and validate our methodology on an in vivo dataset. This dataset consists of 241 signatures collected from in vivo hyperspectral imaging of patients of both genders and Caucasian, Asian and African American ethnicities. In addition, we also extend our methodology past the visible region and through the short-wave infrared region of the electromagnetic spectrum. We find promising results when comparing the estimated skin parameters to the ground truth, demonstrating good agreement with well-established physiological precepts. This methodology can have potential use in non-invasive skin anomaly detection and for developing minimally invasive pre-screening tools.

  12. Constraining blazar physics with polarization signatures

    NASA Astrophysics Data System (ADS)

    Zhang, Haocheng; Boettcher, Markus; Li, Hui

    2016-01-01

    Blazars are active galactic nuclei whose jets are directed very close to our line of sight. They emit nonthermal-dominated emission from radio to gamma-rays, with the radio to optical emissions known to be polarized. Both radiation and polarization signatures can be strongly variable. Observations have shown that sometimes strong multiwavelength flares are accompanied by drastic polarization variations, indicating active participation of the magnetic field during flares. We have developed a 3D multi-zone time-dependent polarization-dependent radiation transfer code, which enables us to study the spectral and polarization signatures of blazar flares simultaneously. By combining this code with a Fokker-Planck nonthermal particle evolution scheme, we are able to derive simultaneous fits to time-dependent spectra, multiwavelength light curves, and time-dependent optical polarization signatures of a well-known multiwavelength flare with 180 degree polarization angle swing of the blazar 3C279. Our work shows that with detailed consideration of light travel time effects, the apparently symmetric time-dependent radiation and polarization signatures can be naturally explained by a straight, helically symmetric jet pervaded by a helical magnetic field, without the need of any asymmetric structures. Also our model suggests that the excess in the nonthermal particles during flares can originate from magnetic reconnection events, initiated by a shock propagating through the emission region. Additionally, the magnetic field should generally revert to its initial topology after the flare. We conclude that such shock-initiated magnetic reconnection event in an emission environment with relatively strong magnetic energy can be the driver of multiwavelength flares with polarization angle swings. Future statistics on such observations will constrain general features of such events, while magneto-hydrodynamic simulations will provide physical scenarios for the magnetic field evolution

  13. Radiative neutron capture as a counting technique at pulsed spallation neutron sources: a review of current progress.

    PubMed

    Schooneveld, E M; Pietropaolo, A; Andreani, C; Perelli Cippo, E; Rhodes, N J; Senesi, R; Tardocchi, M; Gorini, G

    2016-09-01

    Neutron scattering techniques are attracting an increasing interest from scientists in various research fields, ranging from physics and chemistry to biology and archaeometry. The success of these neutron scattering applications is stimulated by the development of higher performance instrumentation. The development of new techniques and concepts, including radiative capture based neutron detection, is therefore a key issue to be addressed. Radiative capture based neutron detectors utilize the emission of prompt gamma rays after neutron absorption in a suitable isotope and the detection of those gammas by a photon counter. They can be used as simple counters in the thermal region and (simultaneously) as energy selector and counters for neutrons in the eV energy region. Several years of extensive development have made eV neutron spectrometers operating in the so-called resonance detector spectrometer (RDS) configuration outperform their conventional counterparts. In fact, the VESUVIO spectrometer, a flagship instrument at ISIS serving a continuous user programme for eV inelastic neutron spectroscopy measurements, is operating in the RDS configuration since 2007. In this review, we discuss the physical mechanism underlying the RDS configuration and the development of associated instrumentation. A few successful neutron scattering experiments that utilize the radiative capture counting techniques will be presented together with the potential of this technique for thermal neutron diffraction measurements. We also outline possible improvements and future perspectives for radiative capture based neutron detectors in neutron scattering application at pulsed neutron sources. PMID:27502571

  14. Radiative neutron capture as a counting technique at pulsed spallation neutron sources: a review of current progress

    NASA Astrophysics Data System (ADS)

    Schooneveld, E. M.; Pietropaolo, A.; Andreani, C.; Perelli Cippo, E.; Rhodes, N. J.; Senesi, R.; Tardocchi, M.; Gorini, G.

    2016-09-01

    Neutron scattering techniques are attracting an increasing interest from scientists in various research fields, ranging from physics and chemistry to biology and archaeometry. The success of these neutron scattering applications is stimulated by the development of higher performance instrumentation. The development of new techniques and concepts, including radiative capture based neutron detection, is therefore a key issue to be addressed. Radiative capture based neutron detectors utilize the emission of prompt gamma rays after neutron absorption in a suitable isotope and the detection of those gammas by a photon counter. They can be used as simple counters in the thermal region and (simultaneously) as energy selector and counters for neutrons in the eV energy region. Several years of extensive development have made eV neutron spectrometers operating in the so-called resonance detector spectrometer (RDS) configuration outperform their conventional counterparts. In fact, the VESUVIO spectrometer, a flagship instrument at ISIS serving a continuous user programme for eV inelastic neutron spectroscopy measurements, is operating in the RDS configuration since 2007. In this review, we discuss the physical mechanism underlying the RDS configuration and the development of associated instrumentation. A few successful neutron scattering experiments that utilize the radiative capture counting techniques will be presented together with the potential of this technique for thermal neutron diffraction measurements. We also outline possible improvements and future perspectives for radiative capture based neutron detectors in neutron scattering application at pulsed neutron sources.

  15. L-Boronophenylalanine-Mediated Boron Neutron Capture Therapy for Malignant Glioma Progressing After External Beam Radiation Therapy: A Phase I Study

    SciTech Connect

    Kankaanranta, Leena; Seppaelae, Tiina; Koivunoro, Hanna; Vaelimaeki, Petteri; Beule, Annette; Collan, Juhani; Kortesniemi, Mika; Uusi-Simola, Jouni; Kotiluoto, Petri; Auterinen, Iiro; Seren, Tom; Paetau, Anders; Saarilahti, Kauko; Savolainen, Sauli; Joensuu, Heikki

    2011-06-01

    Purpose: To investigate the safety of boronophenylalanine-mediated boron neutron capture therapy (BNCT) in the treatment of malignant gliomas that progress after surgery and conventional external beam radiation therapy. Methods and Materials: Adult patients who had histologically confirmed malignant glioma that had progressed after surgery and external beam radiotherapy were eligible for this Phase I study, provided that >6 months had elapsed from the last date of radiation therapy. The first 10 patients received a fixed dose, 290 mg/kg, of L-boronophenylalanine-fructose (L-BPA-F) as a 2-hour infusion before neutron irradiation, and the remaining patients were treated with escalating doses of L-BPA-F, either 350 mg/kg, 400 mg/kg, or 450 mg/kg, using 3 patients on each dose level. Adverse effects were assessed using National Cancer Institute Common Toxicity Criteria version 2.0. Results: Twenty-two patients entered the study. Twenty subjects had glioblastoma, and 2 patients had anaplastic astrocytoma, and the median cumulative dose of prior external beam radiotherapy was 59.4 Gy. The maximally tolerated L-BPA-F dose was reached at the 450 mg/kg level, where 4 of 6 patients treated had a grade 3 adverse event. Patients who were given >290 mg/kg of L-BPA-F received a higher estimated average planning target volume dose than those who received 290 mg/kg (median, 36 vs. 31 Gy [W, i.e., a weighted dose]; p = 0.018). The median survival time following BNCT was 7 months. Conclusions: BNCT administered with an L-BPA-F dose of up to 400 mg/kg as a 2-hour infusion is feasible in the treatment of malignant gliomas that recur after conventional radiation therapy.

  16. Wake Signature Detection

    NASA Astrophysics Data System (ADS)

    Spedding, Geoffrey R.

    2014-01-01

    An accumulated body of quantitative evidence shows that bluff-body wakes in stably stratified environments have an unusual degree of coherence and organization, so characteristic geometries such as arrays of alternating-signed vortices have very long lifetimes, as measured in units of buoyancy timescales, or in the downstream distance scaled by a body length. The combination of pattern geometry and persistence renders the detection of these wakes possible in principle. It now appears that identifiable signatures can be found from many disparate sources: Islands, fish, and plankton all have been noted to generate features that can be detected by climate modelers, hopeful navigators in open oceans, or hungry predators. The various types of wakes are reviewed with notes on why their signatures are important and to whom. A general theory of wake pattern formation is lacking and would have to span many orders of magnitude in Reynolds number.

  17. Recent Progress at LBNL on Characterization of Laser WakefieldAccelerated Electron Bunches using Coherent Transition Radiation

    SciTech Connect

    Plateau, Guillaume R.; Esarey, Eric H.; Geddes, Cameron G.R.; Leemans, Wim P.; Matlis, Nicholas H.; Schroeder, Carl B.; van Tilborg,Jeroen; Toth, Csaba

    2007-06-25

    At LBNL, laser wakefield accelerators (LWFA) can now produce ultra-short electron bunches with energies up to 1 GeV [1]. As femtosecond electron bunches exit the plasma they radiate an intense burst in the terahertz range [2,3] via coherent transition radiation (CTR). Measuring the CTR properties allows non-invasive bunchlength diagnostics [4], a key to continuing rapid advance in LWFA technology. Experimental bunch length characterization for two different energy regimes through bolometric analysis and electro-optic (EO) sampling are presented. Measurements demonstrate both shot-to-shot stability of bunch parameters, and femtosecond synchronization between the bunch, the THz pulse, and the laser beam. In addition, this method of CTR generation provides THz pulses of very high peak power suitable for applications. Recent results reveal LWFA to be a promising intense ultrafast THz source.

  18. Effect of LET and microdistribution of radiation on the transformation in vitro and in vivo. Comprehensive progress report

    SciTech Connect

    Little, J.B.

    1983-09-01

    Work has involved the following three areas: (1) an investigation of the mechanisms of radiation carcinogenesis by studying the events involved in the process of malignant transformation of mouse 10 T-1/2 cells; (2) an investigation of the effects of promoting agents on radiation-induced transformation in vitro; and (3) an investigation of the induction of transformation by internally emitting radionuclides incorporated into cellular DNA. The latter area has been extended to include studies of mutagenesis by these radionuclides in human lymphoblasts, and molecular measurements of DNA strand breaks. During the past year, research has focused on the first area, as well as on studies of the mutagenic effects of incorporated radionuclides.

  19. Investigation of microscopic radiation damage in waste forms using ODNMR and AEM techniques. 1997 annual progress report

    SciTech Connect

    Liu, G.

    1997-09-01

    'This project seeks to understand the microscopic effects of radiation damage in nuclear waste forms. The authors approach to this challenge encompasses studies in electron microscopy, laser spectroscopy, and computational modeling and simulation. During this first year of the project, efforts have focused on a-decay induced microscopic damage in crystalline orthophosphates (YPO{sub 4} and LuPO{sub 4}) that contain the short-lived a-emitting isotope {sup 244}Cm (t{sub 1/2} = 18.1 y). The samples that they studied were synthesized in 1980 and the initial {sup 244}Cm concentration was {approximately}1%. Studying these materials is of importance to nuclear waste management because of the opportunity to gain insight into accumulated radiation damage and the influence of aging on such damage. These factors are critical to the long-term performance of actual waste forms [1]. Lanthanide orthophosphates, including LuPO{sub 4} and YPO{sub 4}, have been suggested as waste forms for high level nuclear waste [2] and potential hosts for excess weapons plutonium [3,4]. The work is providing insight into the characteristics of these previously known radiation-resistant materials. They have observed loss of crystallinity (partial amorphization) as a direct consequence of prolonged exposure to intense alpha radiolysis in these materials. More importantly, the observation of microscopic cavities in these aged materials provides evidence of significant chemical decomposition that may be difficult to detect in the earlier stages of radiation damage. The preliminary results show that, in characterizing crystalline compounds as high level nuclear waste forms, chemical decomposition effects may be more important than lattice amorphization which has been the focus of many previous studies. More extensive studies, including in-situ analysis of the dynamics of thermal annealing of self-radiation induced amorphization and cavity formation, will be conducted on these aged {sup 244}Cm

  20. Regulation of nucleic acid and protein synthesis: a background study related to the biological effects of radiation. Progress report

    SciTech Connect

    Zamecnik, P.

    1984-01-01

    Progress is reported in the following areas in defining the varied roles of diadenosine 5', 5'''-P/sup 1/, P/sup 4/-tetraphosphate (Ap/sub 4/A) in metabolic events within the living cell: (1) Ap/sub 4/A association with a subunit of DNA polymerase ..cap alpha..; (2) studies on the unusual ordered structure of Ap/sub 4/A and of related bisnucleoside oligophosphates; (3) the utilization of technetium labeled Ap/sub 4/A as a radionuclide diagnostic reagent; and (4) the role of Ap/sub 4/A in the blood clotting mechanism. (ACR)

  1. Distinct microbiological signatures associated with triple negative breast cancer

    PubMed Central

    Banerjee, Sagarika; Wei, Zhi; Tan, Fei; Peck, Kristen N.; Shih, Natalie; Feldman, Michael; Rebbeck, Timothy R.; Alwine, James C.; Robertson, Erle S.

    2015-01-01

    Infectious agents are the third highest human cancer risk factor and may have a greater role in the origin and/or progression of cancers, and related pathogenesis. Thus, knowing the specific viruses and microbial agents associated with a cancer type may provide insights into cause, diagnosis and treatment. We utilized a pan-pathogen array technology to identify the microbial signatures associated with triple negative breast cancer (TNBC). This technology detects low copy number and fragmented genomes extracted from formalin-fixed paraffin embedded archival tissues. The results, validated by PCR and sequencing, define a microbial signature present in TNBC tissue which was underrepresented in normal tissue. Hierarchical clustering analysis displayed two broad microbial signatures, one prevalent in bacteria and parasites and one prevalent in viruses. These signatures demonstrate a new paradigm in our understanding of the link between microorganisms and cancer, as causative or commensal in the tumor microenvironment and provide new diagnostic potential. PMID:26469225

  2. Signatures of nonthermal melting.

    PubMed

    Zier, Tobias; Zijlstra, Eeuwe S; Kalitsov, Alan; Theodonis, Ioannis; Garcia, Martin E

    2015-09-01

    Intense ultrashort laser pulses can melt crystals in less than a picosecond but, in spite of over thirty years of active research, for many materials it is not known to what extent thermal and nonthermal microscopic processes cause this ultrafast phenomenon. Here, we perform ab-initio molecular-dynamics simulations of silicon on a laser-excited potential-energy surface, exclusively revealing nonthermal signatures of laser-induced melting. From our simulated atomic trajectories, we compute the decay of five structure factors and the time-dependent structure function. We demonstrate how these quantities provide criteria to distinguish predominantly nonthermal from thermal melting. PMID:26798822

  3. Signature CERN-URSS

    ScienceCinema

    None

    2011-04-25

    Le DG W.Jentschke souhaite la bienvenue à l'assemblée et aux invités pour la signature du protocole entre le Cern et l'URSS qui est un événement important. C'est en 1955 que 55 visiteurs soviétiques ont visité le Cern pour la première fois. Le premier DG au Cern, F.Bloch, et Mons.Amaldi sont aussi présents. Tandis que le discours anglais de W.Jentschke est traduit en russe, le discours russe de Mons.Morozov est traduit en anglais.

  4. Signatures of nonthermal melting

    PubMed Central

    Zier, Tobias; Zijlstra, Eeuwe S.; Kalitsov, Alan; Theodonis, Ioannis; Garcia, Martin E.

    2015-01-01

    Intense ultrashort laser pulses can melt crystals in less than a picosecond but, in spite of over thirty years of active research, for many materials it is not known to what extent thermal and nonthermal microscopic processes cause this ultrafast phenomenon. Here, we perform ab-initio molecular-dynamics simulations of silicon on a laser-excited potential-energy surface, exclusively revealing nonthermal signatures of laser-induced melting. From our simulated atomic trajectories, we compute the decay of five structure factors and the time-dependent structure function. We demonstrate how these quantities provide criteria to distinguish predominantly nonthermal from thermal melting. PMID:26798822

  5. Radiation-dose estimates and hazard evaluations for inhaled airborne radionuclides. Annual progress report, July 1981-June 1982

    SciTech Connect

    Mewhinney, J.A.

    1983-06-01

    The objective was to conduct confirmatory research on aerosol characteristics and the resulting radiation dose distribution in animals following inhalation and to provide prediction of health consequences in humans due to airborne radioactivity which might be released in normal operations or under accident conditions during production of nuclear fuel composed of mixed oxides of U and Pu. Four research reports summarize the results of specific areas of research. The first paper details development of a method for determination of specific surface area of small samples of mixed oxide or pure PuO/sub 2/ particles. The second paper details the extension of the biomathematical model previously used to describe retention, distribution and excretion of Pu from these mixed oxide aerosols to include a description of Am and U components of these aerosols. The third paper summarizes the biological responses observed in radiation dose pattern studies in which dogs, monkeys and rate received inhalation exposures to either 750/sup 0/C heat treated UO/sub 2/ + PuO/sub 2/, 1750/sup 0/C heat-treated (U,Pu)O/sub 2/ or 850/sup 0/C heat-treated pure PuO/sub 2/. The fourth paper described dose-response studies in which rats were exposed to (U,Pu)O/sub 2/ or pure PuO/sub 2/. This paper updates earlier reports and summarizes the status of animals through approximately 650 days after inhalation.

  6. Technical progress report: Completion of spectral rotating shadowband radiometers and analysis of atmospheric radiation measurement spectral shortwave data

    SciTech Connect

    Michalsky, J.; Harrison, L.

    1996-04-01

    Our goal in the Atmospheric Radiation Measurement (ARM) Program is the improvement of radiation models used in general circulation models (GCMs), especially in the shortwave, (1) by providing improved shortwave radiometric measurements for the testing of models and (2) by developing methods for retrieving climatologically sensitive parameters that serve as input to shortwave and longwave models. At the Atmospheric Sciences Research Center (ASRC) in Albany, New York, we are acquiring downwelling direct and diffuse spectral irradiance, at six wavelengths, plus downwelling broadband longwave, and upwelling and downwelling broadband shortwave irradiances that we combine with National Weather Service surface and upper air data from the Albany airport as a test data set for ARM modelers. We have also developed algorithms to improve shortwave measurements made at the Southern Great Plains (SGP) ARM site by standard thermopile instruments and by the multifilter rotating shadowband radiometer (MFRSR) based on these Albany data sets. Much time has been spent developing techniques to retrieve column aerosol, water vapor, and ozone from the direct beam spectral measurements of the MFRSR. Additionally, we have had success in calculating shortwave surface albedo and aerosol optical depth from the ratio of direct to diffuse spectral reflectance.

  7. Metastasis-inducing proteins are widely expressed in human brain metastases and associated with intracranial progression and radiation response

    PubMed Central

    Zakaria, Rasheed; Platt-Higgins, Angela; Rathi, Nitika; Crooks, Daniel; Brodbelt, Andrew; Chavredakis, Emmanuel; Lawson, David; Jenkinson, Michael D; Rudland, Philip S

    2016-01-01

    Background: Understanding the factors that drive recurrence and radiosensitivity in brain metastases would improve prediction of outcomes, treatment planning and development of therapeutics. We investigated the expression of known metastasis-inducing proteins in human brain metastases. Methods: Immunohistochemistry on metastases removed at neurosurgery from 138 patients to determine the degree and pattern of expression of the proteins S100A4, S100P, AGR2, osteopontin (OPN) and the DNA repair marker FANCD2. Validation of significant findings in a separate prospective series with the investigation of intra-tumoral heterogeneity using image-guided sampling. Assessment of S100A4 expression in brain metastatic and non-metastatic primary breast carcinomas. Results: There was widespread staining for OPN, S100A4, S100P and AGR2 in human brain metastases. Positive staining for S100A4 was independently associated with a shorter time to intracranial progression after resection in multivariate analysis (hazard ratio for negative over positive staining=0.17, 95% CI: 0.04–0.74, P=0.018). S100A4 was expressed at the leading edge of brain metastases in image guided sampling and overexpressed in brain metastatic vs non-brain metastatic primary breast carcinomas. Staining for OPN was associated with a significant increase in survival time after post-operative whole-brain radiotherapy in retrospective (OPN negative 3.43 months, 95% CI: 1.36–5.51 vs OPN positive, 11.20 months 95% CI: 7.68–14.72, Log rank test, P<0.001) and validation populations. Conclusions: Proteins known to be involved in cellular adhesion and migration in vitro, and metastasis in vivo are significantly expressed in human brain metastases and may be useful biomarkers of intracranial progression and radiosensitivity. PMID:27100728

  8. Cetuximab, bevacizumab, and irinotecan for patients with primary glioblastoma and progression after radiation therapy and temozolomide: a phase II trial

    PubMed Central

    Hasselbalch, Benedikte; Lassen, Ulrik; Hansen, Steinbjørn; Holmberg, Mats; Sørensen, Morten; Kosteljanetz, Michael; Broholm, Helle; Stockhausen, Marie-Thérése; Poulsen, Hans Skovgaard

    2010-01-01

    The aim of this clinical trial was to investigate safety and efficacy when combining cetuximab with bevacizumab and irinotecan in patients with recurrent primary glioblastoma multiforme (GBM). Patients were included with recurrent primary GBM and progression within 6 months of ending standard treatment (radiotherapy and temozolomide). Bevacizumab and irinotecan were administered IV every 2 weeks. The first 10 patients received bevacizumab 5 mg/kg, but this was increased to 10 mg/kg after interim safety analysis. Irinotecan dose was based on whether patients were taking enzyme-inducing antiepileptic drugs or not: 340 and 125 mg/m2, respectively. Cetuximab 400 mg/m2 as loading dose followed by 250 mg/m2 weekly was administered IV. Forty-three patients were enrolled in the trial, of which 32 were available for response. Radiographic responses were noted in 34%, of which 2 patients had complete responses and 9 patients had partial responses. The 6-month progression-free survival probability was 30% and median overall survival was 29 weeks (95% CI: 23–37 weeks). One patient had lacunar infarction, 1 patient had multiple pulmonary embolisms, and 3 patients had grade 3 skin toxicity, for which 1 patient needed plastic surgery. One patient was excluded due to suspicion of interstitial lung disease. Three patients had deep-vein thrombosis; all continued on study after adequate treatment. Cetuximab in combination with bevacizumab and irinotecan in recurrent GBM is well tolerated except for skin toxicity, with an encouraging response rate. However, the efficacy data do not seem to be superior compared with results with bevacizumab and irinotecan alone. PMID:20406901

  9. Positive immunohistochemical staining of gammaH2AX is associated with tumor progression in gastric cancers from radiation-exposed patients.

    PubMed

    Sentani, Kazuhiro; Oue, Naohide; Sakamoto, Naoya; Nishisaka, Takashi; Fukuhara, Toshiyuki; Matsuura, Hiroo; Yasui, Wataru

    2008-11-01

    To elucidate the mechanism of radiation-induced cancers, molecular analysis of cancers in atomic bomb (A-bomb) exposure is important. DNA double-strand breaks (DSBs) are thought to be caused by the deleterious effects of ionizing radiation, and gammaH2AX (serine 139 phosphorylated form of histone H2AX) is reported to be a significant marker for DSBs. In the present study, we performed immunohistochemical analysis of gammaH2AX in gastric cancers (GCs) from 66 exposed and 47 non-exposed patients who developed GC after the bombing. Of the 47 GCs from non-exposed patients, 6 (13%) cases showed nuclear positive staining for gammaH2AX, whereas of the 66 GCs from exposed patients, 20 (30%) cases were positive (P=0.0405). However, among stage I GC, there was no significant difference in gammaH2AX expression frequency between exposed patients and non-exposed patients. Among exposed patients, stage II-IV cases were more frequently positive for gammaH2AX than stage I cases (P=0.0197). Among GCs from non-exposed patients, gammaH2AX staining showed no significant association with Lauren's classification, depth of invasion, lymph node metastasis or TNM stage. These results suggest that the characteristics of tumor cells differ between GCs from exposed and non-exposed patients. DSBs may be involved in progression of GC in exposed patients. PMID:18949412

  10. Advanced spectral signature discrimination algorithm

    NASA Astrophysics Data System (ADS)

    Chakravarty, Sumit; Cao, Wenjie; Samat, Alim

    2013-05-01

    This paper presents a novel approach to the task of hyperspectral signature analysis. Hyperspectral signature analysis has been studied a lot in literature and there has been a lot of different algorithms developed which endeavors to discriminate between hyperspectral signatures. There are many approaches for performing the task of hyperspectral signature analysis. Binary coding approaches like SPAM and SFBC use basic statistical thresholding operations to binarize a signature which are then compared using Hamming distance. This framework has been extended to techniques like SDFC wherein a set of primate structures are used to characterize local variations in a signature together with the overall statistical measures like mean. As we see such structures harness only local variations and do not exploit any covariation of spectrally distinct parts of the signature. The approach of this research is to harvest such information by the use of a technique similar to circular convolution. In the approach we consider the signature as cyclic by appending the two ends of it. We then create two copies of the spectral signature. These three signatures can be placed next to each other like the rotating discs of a combination lock. We then find local structures at different circular shifts between the three cyclic spectral signatures. Texture features like in SDFC can be used to study the local structural variation for each circular shift. We can then create different measure by creating histogram from the shifts and thereafter using different techniques for information extraction from the histograms. Depending on the technique used different variant of the proposed algorithm are obtained. Experiments using the proposed technique show the viability of the proposed methods and their performances as compared to current binary signature coding techniques.

  11. Clustering signatures classify directed networks

    NASA Astrophysics Data System (ADS)

    Ahnert, S. E.; Fink, T. M. A.

    2008-09-01

    We use a clustering signature, based on a recently introduced generalization of the clustering coefficient to directed networks, to analyze 16 directed real-world networks of five different types: social networks, genetic transcription networks, word adjacency networks, food webs, and electric circuits. We show that these five classes of networks are cleanly separated in the space of clustering signatures due to the statistical properties of their local neighborhoods, demonstrating the usefulness of clustering signatures as a classifier of directed networks.

  12. Multimodal signature modeling of humans

    NASA Astrophysics Data System (ADS)

    Cathcart, J. Michael; Kocher, Brian; Prussing, Keith; Lane, Sarah; Thomas, Alan

    2010-04-01

    Georgia Tech been investigating method for the detection of covert personnel in traditionally difficult environments (e.g., urban, caves). This program focuses on a detailed phenomenological analysis of human physiology and signatures with the subsequent identification and characterization of potential observables. Both aspects are needed to support the development of personnel detection and tracking algorithms. The difficult nature of these personnel-related problems dictates a multimodal sensing approach. Human signature data of sufficient and accurate quality and quantity do not exist, thus the development of an accurate signature model for a human is needed. This model should also simulate various human activities to allow motion-based observables to be exploited. This paper will describe a multimodal signature modeling approach that incorporates human physiological aspects, thermoregulation, and dynamics into the signature calculation. This approach permits both passive and active signatures to be modeled. The focus of the current effort involved the computation of signatures in urban environments. This paper will discuss the development of a human motion model for use in simulating both electro-optical signatures and radar-based signatures. Video sequences of humans in a simulated urban environment will also be presented; results using these sequences for personnel tracking will be presented.

  13. Genetic engineering of a radiation-resistant bacterium for biodegradation of ixed wastes. 1998 annual progress report

    SciTech Connect

    Lidstrom, M.E.

    1998-06-01

    'Because of their tolerance to very high levels of ionizing radiation, members of the genus Deinococcus have received considerable attention over the past years. The type species of the genus, Deinococcus radiodurans, has been studied extensively in several labs. Although researchers are only beginning to understand the mechanisms by which this Gram-positive bacterium is able to repair massive DNA damage after radiation dosages as high as 5 Mrad, it has become evident that its recombination machinery has several unique characteristics (1--4). The aim of the present studies is to engineer D. radiodurans into a detoxifier for bioremediation of complex waste mixtures, containing heavy metals, halo-organics and radionuclides, making use of its ability to be biologically active in environments where they will be exposed to high levels of radiation. For that purpose, the authors aim to clone and express several broad spectrum oxygenases and heavy metal resistance determinants, and test survival and activities of these strains in artificial mixtures of contaminants, designed to simulate DOE mixed waste streams. This report summarizes work after 0.5 year of a 3-year project. The initial studies have focused on the development of an insertional expression system for D. radiodurans R1. This effort has involved two parts, namely: (1) promoter analysis, and (2) development of insertion systems. Several studies have shown that the expression signals used by D. radiodurans differ considerably from those found in other bacteria. Although D. radiodurans contains a typical eubacterial RNA polymerase core enzyme (based on TBLASTN searches on the genome sequence), Escherichia coli promoters are not recognized in D. radiodurans and vice versa (5). To expand the basic understanding of the requirements for transcription, and to optimize expression of (heterologous) genes, they will follow two strategies. First, a promoter-probe vector is being developed for the selection of promoter

  14. Nature of oxygen containing radicals in radiation chemistry and photochemistry of aqueous solutions. Annual progress report, September 1979-July 1980

    SciTech Connect

    Czapski, G.

    1980-01-01

    During this year, emphasis will be given on the properties of HO/sub 2/ and O/sub 2//sup -/ and OH, mainly in their role in biological systems. We will continue to study and elucidate how O/sub 2//sup -/ reacts in biological systems. The toxicity of O/sub 2//sup -/ is quite well established but the mechanism is still obscure. One way O/sub 2//sup -/ is toxic is that OH is formed from O/sub 2//sup -/ through reduction of Fe/sup 3 +/, and subsequently the reaction of Fe/sup 2 +/ with H/sub 2/O/sub 2/ (Fenton reaction). This mechanism is sometimes called the Haber Weiss Reaction. We will study if reduction of Fe/sup 3 +/ complexes by O/sub 2//sup -/ in biological systems does catalyze the Haber Weiss reaction and if OH is formed in this mechanism. The role of oxygen, radiosensitizers in radiation damage of bacteriophages and cells will be further studied, as well as on E. coli and enzymes. Use of different mutants, such as ones with repair deficiencies, or others which are deficient in glutathione will help to elucidate the role of O/sub 2//sup -/ and O/sub 2/ toxicity. We will try to elucidate the formation and role of OH, O/sub 2//sup -/ and O/sub 2/ in these systems as well as the relative contribution of endogenous and exogenous damage, and the role of direct and indirect radiation damage to cells. As there is some doubt how and if SOD protects cells from irradiation as literature results show lots of conflict, we will try to clear this point, in studies with E. coli mutants, and adding SOD endogenously and exogenously. We also intend to study if SOD (super oxide dismutase) does react only with O/sub 2//sup -/ or also with biological peroxides (RO/sub 2/) and hydroperoxides (RO/sub 2/H). Further studies of O/sub 2//sup -/ and O/sub 2/ with various cytochromes, and hemoglobins is planned.

  15. Radiation effects on materials in the near-field of a nuclear waste repository. 1997 annual progress report

    SciTech Connect

    Wang, L.M.; Ewing, R.C.

    1997-11-25

    'Sheet silicates (e.g. micas and clays) are important constituents of a wide variety of geological formations such as granite, basalt, and sandstone. Sheet silicates, particularly clays such as bentonite are common materials in near-field engineered barriers in high-level nuclear waste (HLW) repositories. This is because migration of radionuclides from an underground HLW repository to the geosphere may be significantly reduced by sorption of radionuclides (e.g., Pu, U and Np) onto sheet silicates (e.g., clays and micas) that line the fractures and pores of the rocks along groundwater flowpaths. In addition to surface sorption, it has been suggested that some sheet silicates may also be able to incorporate many radionuclides, such as Cs and Sr, in the inter-layer sites of the sheet structure. However, theability of the sheet silicates to incorporate radionuclides and retard release and migration of radionuclides may be significantly affected by the near-field radiation due to the decay of fission products and actinides. for example, the unique properties of the sheet structures will be lost completely if the structure becomes amorphous due to irradiation effects. Thus, the study of irradiation effects on sheet-structures, such as structural damage and modification of chemical properties, are critical to the performance assessment of long-term repository behavior.'

  16. Does oxygen enhance the radiation-induced inactivation of penicillinase. Progress report, December 1, 1979-November 30, 1980

    SciTech Connect

    Samuni, A.; Kalkstein, A.; Czapski, G.

    1980-01-01

    The radiation-induced inactivation of penicillinase in dilute aqueous solutions buffered with phosphate was studied, by examining enzyme radiosensitivity in the presence of various gases (He, O/sub 2/, H/sub 2/, N/sub 2/O, N/sub 2/O + O/sub 2/). The introduction of either N/sub 2/O or O/sub 2/ was found to reduce the radiodamage. On the other hand H/sub 2/ or N/sub 2/O + O/sub 2/ gas-mixture enhanced the radiosensitivity. In the presence of formate and oxygen, no enzyme inactivation was detected. The results indicated that the specific damaging efficiency of H atoms is almost four-fold higher than that of OH radical; therefore in phosphate buffer, where more than half of the free radicals are H atoms, it is the H radicals that are responsible for the majority of the damage. The superoxide radicals appeared to be completely inactive and did not contribute toward enzyme inactivation. Oxygen was shown to affect the radiosensitivity in two ways. On one side, it protected by converting e/sup -//sub aq/ and H radicals into harmless O/sub 2//sup -/ radicals. On the other side it increased the inactivation by enhancing the damage brought about by OH radicals (OER = 2.8). In the present case the oxygen effect of protection exceeded that of sensitization, thus giving rise to a moderate overall protection effect.

  17. Improved radiation dosimetry/risk estimates to facilitate environmental management of plutonium contaminated sites. 1998 annual progress report

    SciTech Connect

    Scott, B.R.

    1998-06-01

    'The objective of this research is to evaluate distributions of possible alpha radiation doses to the lung, bone, and liver and associated health-risk distributions for plutonium (Pu) inhalation-exposure scenarios relevant to environmental management of PuO{sub 2}-contaminated sites. Currently available dosimetry/risk models do not apply to exposure scenarios where, at most, a small number of highly radioactive PuO{sub 2} particles are inhaled (stochastic exposure [SE] paradigm). For the SE paradigm, risk distributions are more relevant than point estimates of risk. The focus of the research is on the SE paradigm and on high specific activity, alpha-emitting (HSA-aE) particles such as 238 PuO{sub 2} . The scientific goal is to develop a stochastic respiratory tract dosimetry/risk computer model for evaluating the desired absorbed dose distributions and associated health-risk distributions, for Department of Energy (DOE) workers and members of the public. This report summarizes results after 1 year of a 2-year project.'

  18. Scalable hardbody and plume optical signatures

    NASA Astrophysics Data System (ADS)

    Crow, Dennis R.; Hawes, Fred; Braunstein, Matthew; Coker, Charles F.; Smith, Thomas, Jr.

    2004-08-01

    The Fast Line-of-sight Imagery for Target and Exhaust Signatures (FLITES) is a High Performance Computing (HPC-CHSSI) and Missile Defense Agency (MDA) funded effort that provides a scalable program to compute highly resolved temporal, spatial, and spectral hardbody and plume optical signatures. Distributed processing capabilities are included to allow complex, high fidelity, solutions to be generated quickly generated. The distributed processing logic includes automated load balancing algorithms to facilitate scalability using large numbers of processors. To enhance exhaust plume optical signature capabilities, FLITES employs two different radiance transport algorithms. The first algorithm is the traditional Curtis-Godson bandmodel approach and is provided to support comparisons to historical results and high-frame rate production requirements. The second algorithm is the Quasi Bandmodel Line-by-line (QBL) approach, which uses randomly placed "cloned" spectral lines to yield highly resolved radiation spectra for increased accuracy while maintaining tractable runtimes. This capability will provide a significant advancement over the traditional SPURC/SIRRM radiance transport methodology.

  19. Signatures of Reputation

    NASA Astrophysics Data System (ADS)

    Bethencourt, John; Shi, Elaine; Song, Dawn

    Reputation systems have become an increasingly important tool for highlighting quality information and filtering spam within online forums. However, the dependence of a user's reputation on their history of activities seems to preclude any possibility of anonymity. We show that useful reputation information can, in fact, coexist with strong privacy guarantees. We introduce and formalize a novel cryptographic primitive we call signatures of reputation which supports monotonic measures of reputation in a completely anonymous setting. In our system, a user can express trust in others by voting for them, collect votes to build up her own reputation, and attach a proof of her reputation to any data she publishes, all while maintaining the unlinkability of her actions.

  20. Neural signatures of autism

    PubMed Central

    Kaiser, Martha D.; Hudac, Caitlin M.; Shultz, Sarah; Lee, Su Mei; Cheung, Celeste; Berken, Allison M.; Deen, Ben; Pitskel, Naomi B.; Sugrue, Daniel R.; Voos, Avery C.; Saulnier, Celine A.; Ventola, Pamela; Wolf, Julie M.; Klin, Ami; Vander Wyk, Brent C.; Pelphrey, Kevin A.

    2010-01-01

    Functional magnetic resonance imaging of brain responses to biological motion in children with autism spectrum disorder (ASD), unaffected siblings (US) of children with ASD, and typically developing (TD) children has revealed three types of neural signatures: (i) state activity, related to the state of having ASD that characterizes the nature of disruption in brain circuitry; (ii) trait activity, reflecting shared areas of dysfunction in US and children with ASD, thereby providing a promising neuroendophenotype to facilitate efforts to bridge genomic complexity and disorder heterogeneity; and (iii) compensatory activity, unique to US, suggesting a neural system–level mechanism by which US might compensate for an increased genetic risk for developing ASD. The distinct brain responses to biological motion exhibited by TD children and US are striking given the identical behavioral profile of these two groups. These findings offer far-reaching implications for our understanding of the neural systems underlying autism. PMID:21078973

  1. Signatures of aging revisited

    SciTech Connect

    Drell, S.; Jeanloz, R.; Cornwall, J.; Dyson, F.; Eardley, D.

    1998-03-18

    This study is a follow-on to the review made by JASON during its 1997 Summer Study of what is known about the aging of critical constituents, particularly the high explosives, metals (Pu, U), and polymers in the enduring stockpile. The JASON report (JSR-97-320) that summarized the findings was based on briefings by the three weapons labs (LANL, LLNL, SNL). They presented excellent technical analyses covering a broad range of scientific and engineering problems pertaining to determining signatures of aging. But the report also noted: `Missing, however, from the briefings and the written documents made available to us by the labs and DOE, was evidence of an adequately sharp focus and high priorities on a number of essential near-term needs of maintaining weapons in the stockpile.

  2. Multisensors signature prediction workbench

    NASA Astrophysics Data System (ADS)

    Latger, Jean; Cathala, Thierry

    2015-10-01

    Guidance of weapon systems relies on sensors to analyze targets signature. Defense weapon systems also need to detect then identify threats also using sensors. The sensors performance is very dependent on conditions e.g. time of day, atmospheric propagation, background ... Visible camera are very efficient for diurnal fine weather conditions, long wave infrared sensors for night vision, radar systems very efficient for seeing through atmosphere and/or foliage ... Besides, multi sensors systems, combining several collocated sensors with associated algorithms of fusion, provide better efficiency (typically for Enhanced Vision Systems). But these sophisticated systems are all the more difficult to conceive, assess and qualify. In that frame, multi sensors simulation is highly required. This paper focuses on multi sensors simulation tools. A first part makes a state of the Art of such simulation workbenches with a special focus on SE-Workbench. SEWorkbench is described with regards to infrared/EO sensors, millimeter waves sensors, active EO sensors and GNSS sensors. Then a general overview of simulation of targets and backgrounds signature objectives is presented, depending on the type of simulation required (parametric studies, open loop simulation, closed loop simulation, hybridization of SW simulation and HW ...). After the objective review, the paper presents some basic requirements for simulation implementation such as the deterministic behavior of simulation, mandatory to repeat it many times for parametric studies... Several technical topics are then discussed, such as the rendering technique (ray tracing vs. rasterization), the implementation (CPU vs. GP GPU) and the tradeoff between physical accuracy and performance of computation. Examples of results using SE-Workbench are showed and commented.

  3. Signatures of dark matter

    NASA Astrophysics Data System (ADS)

    Baltz, Edward Anthony

    It is well known that most of the mass in the universe remains unobserved save for its gravitational effect on luminous matter. The nature of this ``dark matter'' remains a mystery. From measurements of the primordial deuterium abundance, the theory of big bang nucleosynthesis predicts that there are not enough baryons to account for the amount of dark matter observed, thus the missing mass must take an exotic form. Several promising candidates have been proposed. In this work I will describe my research along two main lines of inquiry into the dark matter puzzle. The first possibility is that the dark matter is exotic massive particles, such as those predicted by supersymmetric extensions to the standard model of particle physics. Such particles are generically called WIMPs, for weakly interacting massive particles. Focusing on the so-called neutralino in supersymmetric models, I discuss the possible signatures of such particles, including their direct detection via nuclear recoil experiments and their indirect detection via annihilations in the halos of galaxies, producing high energy antiprotons, positrons and gamma rays. I also discuss signatures of the possible slow decays of such particles. The second possibility is that there is a population of black holes formed in the early universe. Any dark objects in galactic halos, black holes included, are called MACHOs, for massive compact halo objects. Such objects can be detected by their gravitational microlensing effects. Several possibilities for sources of baryonic dark matter are also interesting for gravitational microlensing. These include brown dwarf stars and old, cool white dwarf stars. I discuss the theory of gravitational microlensing, focusing on the technique of pixel microlensing. I make predictions for several planned microlensing experiments with ground based and space based telescopes. Furthermore, I discuss binary lenses in the context of pixel microlensing. Finally, I develop a new technique for

  4. Signatures of AGN feedback

    NASA Astrophysics Data System (ADS)

    Wylezalek, D.; Zakamska, N.

    2016-06-01

    Feedback from active galactic nuclei (AGN) is widely considered to be the main driver in regulating the growth of massive galaxies. It operates by either heating or driving the gas that would otherwise be available for star formation out of the galaxy, preventing further increase in stellar mass. Observational proof for this scenario has, however, been hard to come by. We have assembled a large sample of 133 radio-quiet type-2 and red AGN at 0.1signatures are hosted in galaxies that are more `quenched' considering their stellar mass than galaxies with weaker outflow signatures. This correlation is only seen in AGN host galaxies with SFR >100 M_{⊙} yr^{-1} where presumably the coupling of the AGN-driven wind to the gas is strongest. This observation is consistent with the AGN having a net suppression, or `negative' impact, through feedback on the galaxies' star formation history.

  5. Correlation of chromosome patterns in human leukemic cells with exposure to chemicals and/or radiation. Progress report, July 1992--August 1993

    SciTech Connect

    Rowley, J.D.

    1993-09-01

    Progress in identification of chromosomal transformations associated with leukemogenesis is described. In particular progress in DNA cloning of chromosomal break points in human cancer patients is described.

  6. New online signature acquisition system

    NASA Astrophysics Data System (ADS)

    Oulefki, Adel; Mostefai, Messaoud; Abbadi, Belkacem; Djebrani, Samira; Bouziane, Abderraouf; Chahir, Youssef

    2013-01-01

    We present a nonconstraining and low-cost online signature acquisition system that has been developed to enhance the performances of an existing multimodal biometric authentication system (based initially on both voice and image modalities). A laboratory prototype has been developed and validated for an online signature acquisition.

  7. BI-08MICROVESICLES CAN DISTINGUISH BETWEEN TUMOR PROGRESSION AND TREATMENT EFFECT/PSEUDOPROGRESSION IN GLIOBLASTOMA PATIENTS TREATED WITH RADIATION AND TEMOZOLOMIDE

    PubMed Central

    Evans, Sydney M.; Koch, Cameron J.; Lustig, Robert

    2014-01-01

    The standard of care for glioblastoma (GB) is radiation therapy (RT) and temozolomide (TMZ) following optimal surgery. This regimen has been accompanied by an increase in the occurrence of equivocal imaging findings, e.g. tumor progression vs. treatment effect (TE), which includes pseudoprogression (PsP). Thus decisions regarding further treatment are difficult and often delayed. None of the current imaging methods for identifying TE/PsP have proven sensitive and specific. Therefore, we developed a method to isolate microvesicles (MV) from blood sample in patients with GB. MV are defined herein as lipid membrane-bound sacs with a diameter >300 nm. METHODS: 3 ml citrated blood was collected from GB patients at their RT simulation and at multiple times during and following treatment. MV were isolated during multiple centrifugations (300g, 2500g, 15,000g). The pellet from the final spin was analyzed using flow cytometry. Antibodies to phosphotidylserine were used to identify the MV. RESULTS: We analyzed 16 blood samples from 10 GB patients that met analysis criteria: the MV sample was obtained at or following the completion of CRT and, a definitive diagnosis (TP, TE or PSP) was reached within 60 days of the date of the sample. MV counts in the patients with stable disease or TE/PsP were significantly lower than patients who developed recurrence or died of their disease (p = 0.0385). Based on MRI and/or pathological assessment, 2 patients have died of their disease, 1 patient is alive with recurrence, 3 patients have stable disease and 4 patients are being followed for PsP vs. tumor progression (TP). SUMMARY/CONCLUSION: These preliminary data suggest that the analysis of blood (liquid biopsy) for MV may be useful to distinguish TE/PsP from TP in GB patients. MVs may be valuable in addition to standard imaging for decision making in patients with equivocal imaging findings.

  8. Intake of high-fat diet stimulates the risk of ultraviolet radiation-induced skin tumors and malignant progression of papillomas to carcinoma in SKH-1 hairless mice

    SciTech Connect

    Vaid, Mudit; Singh, Tripti; Prasad, Ram; Katiyar, Santosh K.

    2014-01-01

    Previously, we showed that administration of a high-fat diet (HF-diet) to C57BL/6 mice exacerbates their response to short-term UVB radiation-induced inflammation in the skin. To explore the effects of an HF-diet on UVB-induced tumorigenesis, we have used the SKH-1 hairless mouse model in which the mice are exposed to UVB radiation (180 mJ/cm{sup 2}) three times a week for 24 weeks. The development of UVB-induced skin tumors was rapid and the tumor multiplicity and tumor size were significantly higher (P < 0.01–0.005) in the mice fed an HF-diet than the mice fed a control-diet (C-diet). Moreover, the malignant progression of UVB-induced papillomas to carcinomas was higher in HF-diet-fed mice. On analysis of tumors and tumor-uninvolved skin samples from the tumor-bearing mice, we found that administration of an HF-diet significantly enhanced the levels of UVB-induced expression of cyclooxygenase-2 (COX-2), prostaglandin E{sub 2} (P < 0.01), and PGE{sub 2} receptors, and activation of NF-κB in the UVB-exposed skin as well as in tumors. In addition the HF-diet enhanced the expression of proinflammatory cytokines, including tumor necrosis factor-α (P < 0.01), interleukin (IL)-1β (P < 0.01) and IL-6 (P < 0.05) in the UVB-exposed skin as well as in tumors. Western blot analysis revealed that HF-diet enhanced the levels of epidermal cell proliferation, phosphatidylinositol 3-kinase and phosphorylation of Akt at Ser{sup 473} in UVB-exposed skin and skin tumors. Collectively, these data demonstrate that the regular consumption of an HF-diet increases the risk of photocarcinogenesis in mice and that this is associated with enhanced expression of inflammatory mediators in the UVB-exposed skin and tumors. - Highlights: • Consumption of high-fat diet increases UVB-induced skin tumor development in mice. • Intake of high-fat diet stimulates progression of UV-induced papilloma to carcinoma. • Intake of high-fat diet enhances inflammation in UV-exposed skin • Regular

  9. ACCRETING CIRCUMPLANETARY DISKS: OBSERVATIONAL SIGNATURES

    SciTech Connect

    Zhu, Zhaohuan

    2015-01-20

    I calculate the spectral energy distributions of accreting circumplanetary disks using atmospheric radiative transfer models. Circumplanetary disks only accreting at 10{sup –10} M {sub ☉} yr{sup –1} around a 1 M{sub J} planet can be brighter than the planet itself. A moderately accreting circumplanetary disk ( M-dot ∼10{sup −8} M{sub ⊙} yr{sup −1}; enough to form a 10 M{sub J} planet within 1 Myr) around a 1 M{sub J} planet has a maximum temperature of ∼2000 K, and at near-infrared wavelengths (J, H, K bands), this disk is as bright as a late-M-type brown dwarf or a 10 M{sub J} planet with a ''hot start''. To use direct imaging to find the accretion disks around low-mass planets (e.g., 1 M{sub J} ) and distinguish them from brown dwarfs or hot high-mass planets, it is crucial to obtain photometry at mid-infrared bands (L', M, N bands) because the emission from circumplanetary disks falls off more slowly toward longer wavelengths than those of brown dwarfs or planets. If young planets have strong magnetic fields (≳100 G), fields may truncate slowly accreting circumplanetary disks ( M-dot ≲10{sup −9} M{sub ⊙} yr{sup −1}) and lead to magnetospheric accretion, which can provide additional accretion signatures, such as UV/optical excess from the accretion shock and line emission.

  10. On the signature of LINCOS

    NASA Astrophysics Data System (ADS)

    Ollongren, Alexander

    2010-12-01

    Suppose the international SETI effort yields the discovery of some signal of evidently non-natural origin. Could it contain linguistic information formulated in some kind of Lingua Cosmica? One way to get insight into this matter is to consider what specific (bio) linguistic signature( s) could be attached to a cosmic language for interstellar communication—designed by humans or an alien society having reached a level of intelligence (and technology) comparable to or surpassing ours. For this purpose, we consider in the present paper the logico-linguistic system LINCOS for ( A)CETI, developed during a number of years by the author in several papers and a monograph [1]. The system has a two-fold signature, which distinguishes it significantly from natural languages. In fact abstract and concrete signatures can be distinguished. That an abstract kind occurs is due to the manner in which abstractions of reality are represented in LINCOS-texts. They can take compound forms because the system is multi-expressive—partly due to the availability of inductive (recursive) entities. On the other hand, the concrete signature of LINCOS is related to the distribution of delimiters and predefined tokens in texts. Assigning measures to concrete signatures will be discussed elsewhere. The present contribution concentrates on the abstract signature of the language. At the same time, it is realized that an alien Lingua Cosmica might, but not necessarily needs to have this kind of signatures.