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Sample records for 0-50 rad range

  1. 28 CFR 0.50 - General functions.

    2010-07-01

    ..., enforcement, and investigatory activities under section 102 of the Immigration Reform and Control Act of 1986, as amended. Editorial Note: For Federal Register citations affecting § 0.50, see the List of CFR..., abortion, sterilization, credit, and constitutional and civil rights of Indians arising under 25...

  2. ERRATA SHEET for Post-Closure Inspection Report for Corrective Action Unit 407: Roller Coaster RadSafe Area Tonopah Test Range, Nevada, Calendar year 2001; TOPICAL

    The fifth sentence of the first paragraph on Page 1 of the Post Closure Inspection Report for Corrective Action Unit 407: Roller Coaster RadSafe Area, Tonopah Test Range, Nevada erroneously states that Revision 1 of the CR was issued in December of 2001 and was approved by NDEP on January 7, 2002. The sentence should state that Revision 1 of the CR was issued in December of 2001 and was approved by NDEP on February 22, 2002

  3. Unusual isotope effects for diffusion in VH 0.50 and VT 0.50

    Nonclassical diffusion processes for hydrogen isotopes in metals and other solids remain interesting and unresolved challenges. Although numerous diffusion measurements have been performed on dilute solutions of hydrogen, deuterium, and tritium in metals, relatively few results are available for diffusion of hydrogen isotopes in the hydride phases formed at higher concentrations. Since diffusion coefficients are generally dependent upon concentration, this disparity is partially due to the difficulty in preparing samples with identical contents. The vanadium hydride phases are promising candidates to study isotopic diffusion. Recent nuclear magnetic resonance (NMR) studies of proton spin-lattice relaxation times T1 for b.c.t. βphase VH /SUB x/ (0.4< x<0.9) have shown anomalous hydrogen diffusion behavior. Furthermore, the remark ably large differences between the VH /SUB x/ and VD /SUB x/ phase diagrams suggest that significant isotope effects may also occur in the diffusion processes. In fact, several unusual isotope effects in diffusion behavior for VH 0.50 and VT 0.50 are indicated from the present NMR relaxation times. Tritium atoms in β-VT 0.5 diffuse more rapidly and with a smaller activation energy than hydrogen atoms in β-VH 0.5. These inverse isotope effects are related to an enhanced T-atom mobility i β-VT 0.50 that arises from atomic exchange processes between T-atoms on inequivalent interstitial sites

  4. Directional frustration of magnetic moments in (U0.50Dy0.50)Ni2B2C

    Polycrystalline (U0.50Dy0.50)Ni2B2C solid solution was prepared and found by X-ray diffraction to crystallize in BCT LuNi2B2C-type structure (space group I4/mmm) of the end compounds UNi2B2C and DyNi2B2C. AC susceptibility and magnetization show paramagnetic behavior down to 6.5 K, with the values θ=-5(5) K and μeff=7.7(1) μB, compatible with those of the end compounds, and indicate possible cooperative phenomena at lower temperatures. The observed paramagnetism, at variance with antiferromagnetic ordering in (Pr0.50Dy0.50)Ni2B2C, is attributed to a directional frustration of the magnetic moments on the (U,Dy) site

  5. RadLex

    U.S. Department of Health & Human Services — RadLex is a controlled terminology for radiology and serves as a single unified source of radiology terms for radiology practice, education, and research. RadLex is...

  6. Thickness dependent structural, magnetic and magneto-transport properties of epitaxial Nd0.50Sr0.50MnO3 thin films

    Kumar, Pawan; Singh, Hari Krishna

    2016-05-01

    We report the thickness-dependent structural, magnetic and magneto-transport properties in epitaxial Nd0.50Sr0.50MnO3 thin films (10 to 300nm) prepared by DC magnetron sputtering technique on single crystalline (001) oriented substrate LaAlO3. X-ray diffraction pattern reveals the epitaxial growth of all the films and the out-of-plane lattice parameter of films were found to increase with thickness. As thickness of the film increases the paramagnetic insulator (PMI) to ferromagnetic metal (FMM) transition temperature (TC), charge ordered transition temperature (TCO) and magnetic moment were found to increase with a strong bifurcation in ZFC-FC magnetization. The asymmetry in the coercivity seen in field dependent magnetization loops (M-H loops) suggests the presence of exchange bias (EB) effect. While temperature dependent resistivity of films show the semiconducting nature for thickness 10-200nm in temperature range from 5-300K, the film of thickness 300nm shows the insulator to metal transition with transition temperature (TIM) at 175K. Temperature dependent low field magnetoresistance (LFMR) measured at 4kOe found to decrease with thickness and for high field magnetoresistance (HFMR) at 40kOe and 60kOe also show similar dependence and a crossover at intermediate temperature range in the magnitude of MR between 10nm and 200nm films at constant field. Colossal increase in magnetoresistance observed for 10nm film at low temperature.

  7. Reach Address Database (RAD)

    U.S. Environmental Protection Agency — The Reach Address Database (RAD) stores the reach address of each Water Program feature that has been linked to the underlying surface water features (streams,...

  8. RadWorks Project

    National Aeronautics and Space Administration — For the first two years of the project (FY12-13), the RadWorks project has consisted of two top-level elements. The first element involved the prototype and...

  9. Interactions of checkpoint-genes RAD9, RAD17, RAD24 and RAD53 determining radioresistance of Yeast Saccharomyces Cerevisiae

    The mechanisms of genetic control of progress through the division cell cycle (checkpoint-control) in yeast Saccharomyces cerevisiae have been studied intensively. To investigate the role of checkpoint-genes RAD9, RAD17, RAD24, RAD53 in cell radioresistance we have investigated cell sensitivity of double mutants to γ-ray. Double mutants involving various combinations with rad9Δ show epistatic interactions, i.e. the sensitivity of the double mutants to γ-ray was no greater than that of more sensitive of the two single mutants. This suggests that all these genes govern the same pathway. This group of genes was named RAD9-epistasis group. It is interesting to note that the genes RAD9 and RAD53 have positive effect but RAD17 and RAD24 have negative effect on radiosensitivity of yeast cells. Interactions between mutations may differ depending on the agent γ-ray or UV-light, for example mutations rad9Δ and rad24Δ show additive effect for γ-ray and epistatic effect for UV-light

  10. RadGenomics project

    Human health is determined by a complex interplay of factors, predominantly between genetic susceptibility, environmental conditions and aging. The ultimate aim of the RadGenomics (Radiation Genomics) project is to understand the implications of heterogeneity in responses to ionizing radiation arising from genetic variation between individuals in the human population. The rapid progression of the human genome sequencing and the recent development of new technologies in molecular genetics are providing us with new opportunities to understand the genetic basis of individual differences in susceptibility to natural and/or artificial environmental factors, including radiation exposure. The RadGenomics project will inevitably lead to improved protocols for personalized radiotherapy and reductions in the potential side effects of such treatment. The project will contribute to future research into the molecular mechanisms of radiation sensitivity in humans and will stimulate the development of new high-throughput technologies for a broader application of biological and medical sciences. The staff members are specialists in a variety of fields, including genome science, radiation biology, medical science, molecular biology, and informatics, and have joined the RadGenomics project from various universities, companies, and research institutes. The project started in April 2001. (author)

  11. Role of Pr cations and the low temperature transition in Pr{sub 0.50}Sr{sub 0.50}CoO{sub 3}: A comparison to Pr{sub 0.50}Ca{sub 0.50}CoO{sub 3}

    Padilla-Pantoja, J., E-mail: jpadilla@icmab.es [Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus univ. de Bellaterra, E-08193 Bellaterra (Spain); Barón-González, A.J. [Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus univ. de Bellaterra, E-08193 Bellaterra (Spain); Grupo Física de Materiales, Universidad Pedagógica y Tecnológica de Colombia, Tunja (Colombia); Bozzo, B. [Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus univ. de Bellaterra, E-08193 Bellaterra (Spain); Blasco, J. [Instituto de Ciencia de Materiales de Aragón, CSIC-Univ. de Zaragoza, 50009 Zaragoza (Spain); Ritter, C. [Institute Laue Langevin, BP 156, 38042 Grenoble Cedex 9 (France); Herrero-Martín, J. [ALBA Synchrotron Light Source, 08290 Cerdanyola del Vallès, Barcelona (Spain); García-Muñoz, J.L. [Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus univ. de Bellaterra, E-08193 Bellaterra (Spain)

    2014-12-15

    The low temperature properties of Pr{sub 0.50}Sr{sub 0.50}CoO{sub 3} are studied in comparison to Pr{sub 0.50}Ca{sub 0.50}CoO{sub 3}, which is known to exhibit a Pr{sup 3+}/Pr{sup 4+} valence shift below T{sub MI}∼80 K. The evolution of the Pr–O network strongly differs in the Sr and Ca compounds, but both have in common a prominent and sudden contraction of some Pr–O bonds. The structural phase transition that accompanies the so-called magnetocrystalline anisotropy transition at T{sub S}∼120 K in Pr{sub 0.50}Sr{sub 0.50}CoO{sub 3} brings about a notable contraction of some Pr–O{sub 2} bonds. The observations give support to the active participation of Pr-4f electrons at the intriguing magnetostructural transition (T{sub S}) in Pr{sub 0.50}Sr{sub 0.50}CoO{sub 3}. In addition, we have confirmed that (in absence of praseodymium) the magnetostructural transition is suppressed in (Nd{sub 2/3}La{sub 1/3}){sub 0.50}Sr{sub 0.50}CoO{sub 3}, a perovskite with the same average cationic size at the A-site than Pr{sub 0.50}Sr{sub 0.50}CoO{sub 3}.

  12. From first-order magneto-elastic to magneto-structural transition in (Mn,Fe)1.95P0.50Si0.50 compounds

    Dung, N.H.; Zhang, L; Ou, Z.Q.; Brück, E

    2012-01-01

    We report on structural, magnetic, and magnetocaloric properties of MnxFe1.95−xP0.50Si0.50 (x ≥ 1.10) compounds. With increasing the Mn:Fe ratio, a first-order magneto-elastic transition gradually changes into a first-order magneto-structural transition via a second-order magnetic transition. The study also shows that thermal hysteresis can be tuned by varying the Mn:Fe ratio. Small thermal hysteresis (less than 1 K) can be obtained while maintaining a giant magnetocaloric effect. This achiev...

  13. Complex formation in yeast double-strand break repair: participation of Rad51, Rad52, Rad55, and Rad57 proteins.

    Hays, S L; Firmenich, A A; Berg, P

    1995-01-01

    The repair of DNA double-strand breaks in Saccharomyces cerevisiae requires genes of the RAD52 epistasis group, of which RAD55 and RAD57 are members. Here, we show that the x-ray sensitivity of rad55 and rad57 mutant strains is suppressible by overexpression of RAD51 or RAD52. Virtually complete suppression is provided by the simultaneous overexpression of RAD51 and RAD52. This suppression occurs at 23 degrees C, where these mutants are more sensitive to x-rays, as well as at 30 degrees C and...

  14. Electrical conduction mechanism and improved multiferroic properties of NFO/ (Pb0.50Sr0.50) TiO3 bilayer nanostructure composite thin film

    Bala, Kanchan; Ram, Mast; Sharma, Hakikat; Negi, N. S.

    2016-05-01

    Multiferroic 2-2 type layered NFO/ (Pb0.50Sr0.50) TiO3 composite thin film on Pt/TiO2/Si substrate was prepared by novel metallo-Organic process using spin coating technique. The structural and surface morphology were confirmed by X-Ray diffraction (XRD) atomic force microscope (AFM). Significantly improved ferroelectric properties (Ps ˜ 8.69, Pr ˜ 3.19 µC/cm2 and Ec ˜ 419kV/cm) and magnetic properties (Ms), (Mr) and (Hc) is (104emu/cc, 0.8emu/cc and 25Oe.) were observed at room temperature. Our observation provides an effective way to manipulate the conduction behavior to understand the leakage current density of multiferroic composites film at the interface. Poole-Frankel tunneling conduction mechanism dominates the leakage current of films in the relatively high electric filed.

  15. Synthesis, structure, and physicochemical investigations of the new α Cu0.50TiO(PO4) oxyphosphate

    The room-temperature crystal structure of a new Cu(II) oxyphosphate-α Cu0.50IITiO(PO4)-was determined from X-ray single crystals diffraction data, in the monoclinic system, space group P21/c. The refinement from 5561 independent reflections lead to the following parameters: a=7.5612(4)A, b=7.0919(4)A, c=7.4874(4)A, β=122.25(1)o, Z=4, with the final R=0.0198, wR=0.0510. The structure of α Cu0.50IITiO(PO4) can be described as a TiOPO4 framework constituted by chains of tilted corner-sharing [TiO6] octahedra running parallel to the c-axis and cross linked by phosphate [PO4] tetrahedra, where one-half of octahedral cavities created are occupied by Cu atoms. Ti atoms are displaced from the center of octahedra units in alternating long (2.308 A) and short (1.722 A) Ti-O(1) bonds along chains. Such O(1) atoms not linked to P atoms justify the oxyphosphate formulation α Cu0.50TiO(PO4). The divalent cations Cu2+ occupy a Jahn-Teller distorted octahedron sharing two faces with two [TiO6] octahedra. EPR and optical measurements are in good agreement with structural data. The X-ray diffraction results are supported by Raman and infrared spectroscopy studies that confirmed the existence of the infinite chains -Ti-O-Ti-O-Ti-. α Cu0.50TiO(PO4) shows a Curie-Weiss paramagnetic behavior in the temperature range 4-80 K. - Graphical abstract: Projection of the structure of α Cu0.50TiO(PO4) along the a-axis

  16. Identification of cloned genes that complement the rad50-1, rad51-1, rad54-3 and rad55-3 mutations in yeast

    Plasmids that complement the rad50-1, rad51-1, rad54-3 and rad55-3 mutations in yeast, have been isolated. They were obtained by transforming strains, carrying the leu2-112 leu2-3 alleles and the particular rad mutation, with YEp13 plasmids containing near random yeast DNA inserts. Rad+ clones were identified among the Leu+ transformants. Integration by targeting into the RAD55 locus showed that the rad55-3 complementing plasmid contained the actual RAD55 gene. BamHI fragments from each of the plasmids that complement rad50-1, rad51-1 and rad54-3, all of which lacked Rad+ activity, were subcloned into the integrating plasmid YIp5 and the hybrid plasmids were used to transform a Rad+ Ura- strain to Ura+. By genetic mapping, the rad51 and rad54 subclones were shown to integrate at their respective loci. However, the rad50 subclones integrated at a site unlinked to the RAD50 locus. This suggests that no homology exists between this BamHI fragment and the RAD50 gene. Integration at the RAD54 locus of the rad54 subclone made the host cell Ura+ but Rad-; excision of the plasmid was shown to be x-ray inducible and to restore the Ura- Rad+ phenotype. These results indicate that the BamHI fragment of the RAD54 plasmid is internal to the RAD54 gene. We can conclude also that the RAD54 gene is not essential as cells bearing a disrupted copy of this gene are able to survive. Additionally, a plasmid carrying an amber suppressor has been isolated and characterized

  17. Extreme Temperature, Rad-Hard Power Management ASIC Project

    National Aeronautics and Space Administration — Ridgetop Group will design a rad-hard Application Specific Integrated Circuit (ASIC) for spacecraft power management that is functional over a temperature range of...

  18. Rad Pole Cam Development

    The RadPoleCam was developed to provide Department Of Energy (DOE) first responders the capability to assess the radiological and visual condition of remote or inaccessible locations. Real time gamma isotopic identification is provided to the first responder in the form of audio feedback (i.e. spoken through head phones) from a gamma detector mounted on a collapsible pole that can extend from 1 to 9 meters (6 to 29 feet). Simultaneously, selectable direct and side looking visual images are provided from the 5cm (2in) diameter, waterproof probe tip. The lightweight, self contained, ruggedized, system will provide a rapidly deployable field system for visual and radiological search and assessment of confined spaces and extended reach locations

  19. Rad52 and Rad59 exhibit both overlapping and distinct functions

    Feng, Qi; Düring, Louis; Antúnez de Mayolo, Adriana;

    2007-01-01

    annealing of complementary single-stranded DNA in vitro, but only Rad52 interacts with replication protein A and the Rad51 recombinase. We have studied the functional overlap between Rad52 and Rad59 in living cells using chimeras of the two proteins and site-directed mutagenesis. We find that Rad52 and Rad...

  20. Ionizing radiation-induced foci formation of mammalian Rad51 and Rad54 depends on the Rad51 paralogs, but not on Rad52

    Homologous recombination is of major importance for the prevention of genomic instability during chromosome duplication and repair of DNA damage, especially double-strand breaks. Biochemical experiments have revealed that during the process of homologous recombination the RAD52 group proteins, including Rad51, Rad52 and Rad54, are involved in an essential step: formation of a joint molecule between the broken DNA and the intact repair template. Accessory proteins for this reaction include the Rad51 paralogs and BRCA2. The significance of homologous recombination for the cell is underscored by the evolutionary conservation of the Rad51, Rad52 and Rad54 proteins from yeast to humans. Upon treatment of cells with ionizing radiation, the RAD52 group proteins accumulate at the sites of DNA damage into so-called foci. For the yeast Saccharomyces cerevisiae, foci formation of Rad51 and Rad54 is abrogated in the absence of Rad52, while Rad51 foci formation does occur in the absence of the Rad51 paralog Rad55. By contrast, we show here that in mammalian cells, Rad52 is not required for foci formation of Rad51 and Rad54. Furthermore, radiation-induced foci formation of Rad51 and Rad54 is impaired in all Rad51 paralog and BRCA2 mutant cell lines tested, while Rad52 foci formation is not influenced by a mutation in any of these recombination proteins. Despite their evolutionary conservation and biochemical similarities, S. cerevisiae and mammalian Rad52 appear to differentially contribute to the DNA-damage response

  1. Laser-Assisted Synthesis of Mn0.50Zn0.50Fe2O4 Nanomaterial: Characterization and In Vitro Inhibition Activity towards Bacillus subtilis Biofilm

    Shaukat Ali Shahid

    2015-01-01

    Full Text Available There is growing interest in the development of novel nanomaterials with potential antimicrobial activity and lesser toxicity. In the current research work, Mn0.5Zn0.5Fe2O4 nanoparticles were synthesized via a novel coprecipitation cum laser ablation technique yielding fine spinal structured material. The synthesized nanomaterial was structurally characterized by X-ray diffraction technique which confirmed the formation and the crystalline nature of Mn0.50Zn0.50Fe2O4 nanomaterial. The crystallite size determined by Debye-Scherrer’s formula was found to be ~12 nm. The formation of nanoparticles was evidenced by scanning electron microscopy. Energy dispersive X-ray analysis (EDXA was performed for elemental analysis. The synthesized nanomaterial was interestingly found to be an effective antimicrobial agent and inhibited the growth of Bacillus subtilis biofilm formation. The 5 µg of Mn0.5Zn0.5Fe2O4 nanomaterial dissolved in 1 mL of DMSO showed excellent biofilm inhibitory activity 91.23% ± 1.87 against Bacillus subtilis.

  2. Investigations of the regulation of cerebral circulation by means of functional changes observed on unanaesthetized rabbits during hypoxia, paradoxical sleep and after whole-body γ-exposure (850-150 rad dose range)

    Both the general effects and the effects on cerebral circulation of whole-body exposure were studied at doses of 850, 650, 450, 250 and 150 rads. Early functional changes following exposure demonstrated two juxtaposed mechanisms, a central one and a peripheral one. The central process, slightly sensitive to the dose-effect, occurred earlier and should be at the origin of hyperthermia, hyperventilation, tachycardia, skin vasoconstruction and a slight increase of arterial pressure. The peripheral mechanisms, occurring slightly later should be more sensitive to the dose-effect and might be at the origin of hypothermic effects and cardiovascular depression. The increase of cerebral blood flow occurring at the 450 rad dose should be best explained by the presence of vasotropic substances. A twofold component of cerebral vasotonicity should be assumed that would depend on the autonomous nervous system and myogenous autoregulation

  3. RadFlexPro Project

    National Aeronautics and Space Administration — Our proposed multilayered, flexible, graded Z radiation shielding, RadFlexPro, provides radiation protection for astronauts in EVA for NASA's future space missions....

  4. Wallac automatic alarm dosimeter type RAD21

    The Automatic Alarm Dosimeter type RAD 21 is a batterypowered personal dosemeter and exposure rate alarm monitor, designed to be worn on the body, covering an exposure range from 0.1 to 999.9 mR and has an audible alarm which can be pre-set over the range 1 mR h-1 to 250 mR h-1. The instrument is designed to measure x- and γ radiation over the energy range 50 keV to 3 MeV. The facilities and controls, the radiation, electrical, environmental and mechanical characteristics, and the manual, have been evaluated. (U.K.)

  5. Long Term RadNet Quality Data

    U.S. Environmental Protection Agency — This RadNet Quality Data Asset includes all data since initiation and when ERAMS was expanded to become RadNet, name changed to reflect new mission. This includes...

  6. Preferential binding of yeast Rad4-Rad23 complex to damaged DNA

    The yeast Rad4 and Rad23 proteins form a complex that is involved in nucleotide excision repair (NER). Their function in this process is not known yet, but genetic data suggest that they act in an early step in NER. We have purified an epitope-tagged Rad4.Rad23 (tRad4. Rad23) complex from yeast cells, using a clone overproducing Rad4 with a hemagglutinin-tag at its C terminus. tRad4.Rad23 complex purified by both conventional and immuno-affinity chromatography complements the in vitro repair defect of rad4 and rad23 mutant extracts, demonstrating that these proteins are functional in NER. Using electrophoretic mobility shift assays, we show preferential binding of the tRad4.Rad23 complex to damaged DNA in vitro. UV-irradiated, as well as N-acetoxy-2-(acetylamino)fluorene-treated DNA, is efficiently bound by the protein complex. These data suggest that Rad4.Rad23 interacts with DNA damage during NER and may play a role in recognition of the damage

  7. Rare adipose disorders (RADs) masquerading as obesity

    Karen L HERBST

    2012-01-01

    Rare adipose disorders (RADs) including multiple symmetric lipomatosis (MSL),lipedema and Dercum's disease (DD) may be misdiagnosed as obesity.Lifestyle changes,such as reduced caloric intake and increased physical activity are standard care for obesity.Although lifestyle changes and bariatric surgery work effectively for the obesity component of RADs,these treatments do not routinely reduce the abnormal subcutaneous adipose tissue (SAT) of RADs.RAD SAT likely results from the growth of a brown stem cell population with secondary lymphatic dysfunction in MSL,or by primary vascular and lymphatic dysfunction in lipedema and DD.People with RADs do not lose SAT from caloric limitation and increased energy expenditure alone.In order to improve recognition of RADs apart from obesity,the diagnostic criteria,histology and pathophysiology of RADs are presented and contrasted to familial partial lipodystrophies,acquired partial lipodystrophies and obesity with which they may be confused.Treatment recommendations focus on evidencebased data and include lymphatic decongestive therapy,medications and supplements that support loss of RAD SAT.Associated RAD conditions including depression,anxiety and pain will improve as healthcare providers learn to identify and adopt alternative treatment regimens for the abnormal SAT component of RADs.Effective dietary and exercise regimens are needed in RAD populations to improve quality of life and construct advanced treatment regimens for future generations.

  8. Mapping the interaction domains between Rad51B and Rad51C; predictions and experiment

    Rad51B and Rad51C are proteins important in the repair of DNA double strand breaks through homologous recombination. These proteins have been confirmed to form a complex both in vitro and in yeast cells. Homology modeling was used to predict the 3D structures of Rad51B and Rad51C. Similar to Rad51, these proteins appear to have two distinct domains-an N-terminal putative DNA binding domain and a C-terminal domain that contains the Walker A and Walker B motifs that are important for the ATPase activity of these proteins. Deletion mutants were created, based on our models, to determine how the Rad51B/C complex is formed. We have shown that preserving the integrity of an internal beta sheet, predicted in both proteins, is vital to observing complex formation between Rad51B and Rad51C. Our predictions, that the N terminus of Rad51B binds the C terminus of Rad51C, have been verified by yeast two hybrid analysis and co-immunoprecipitation of these protein fragments from baculoviral infected insect cells. By iterative modeling and experiment, we have determined that a 15 amino acid length fragment on Rad51B is critical for binding Rad51C. Point mutations in this fragment are being used to determine the points of contact between Rad51B and Rad51C

  9. Rad51 Paralogs Remodel Pre-synaptic Rad51 Filaments to Stimulate Homologous Recombination

    Taylor, Martin R.G.; Špírek, Mário; Chaurasiya, Kathy R.; Ward, Jordan D.; Carzaniga, Raffaella; Yu, Xiong; Egelman, Edward H.; Collinson, Lucy M.; Rueda, David; Krejci, Lumir; Boulton, Simon J.

    2015-01-01

    Summary Repair of DNA double strand breaks by homologous recombination (HR) is initiated by Rad51 filament nucleation on single-stranded DNA (ssDNA), which catalyzes strand exchange with homologous duplex DNA. BRCA2 and the Rad51 paralogs are tumor suppressors and critical mediators of Rad51. To gain insight into Rad51 paralog function, we investigated a heterodimeric Rad51 paralog complex, RFS-1/RIP-1, and uncovered the molecular basis by which Rad51 paralogs promote HR. Unlike BRCA2, which ...

  10. Complex formation by the human Rad51B and Rad51C DNA repair proteins and their activities in vitro

    Lio, Yi-Ching; Mazin, Alexander V.; Kowalczykowski, Stephen C.; Chen, David J.

    2003-01-01

    The human Rad51 protein is essential for DNA repair by homologous recombination. In addition to Rad51 protein, five paralogs have been identified: Rad51B/Rad51L1, Rad51C/Rad51L2, Rad51D/Rad51L3, XRCC2, and XRCC3. To further characterize a subset of these proteins, recombinant Rad51, Rad51B-(His)(6), and Rad51C proteins were individually expressed employing the baculovirus system, and each was purified from Sf9 insect cells. Evidence from nickel-nitrilotriacetic acid pull-down experiments demonstrates a highly stable Rad51B.Rad51C heterodimer, which interacts weakly with Rad51. Rad51B and Rad51C proteins were found to bind single- and double-stranded DNA and to preferentially bind 3'-end-tailed double-stranded DNA. The ability to bind DNA was elevated with mixed Rad51 and Rad51C, as well as with mixed Rad51B and Rad51C, compared with that of the individual protein. In addition, both Rad51B and Rad51C exhibit DNA-stimulated ATPase activity. Rad51C displays an ATP-independent apparent DNA strand exchange activity, whereas Rad51B shows no such activity; this apparent strand exchange ability results actually from a duplex DNA destabilization capability of Rad51C. By analogy to the yeast Rad55 and Rad57, our results suggest that Rad51B and Rad51C function through interactions with the human Rad51 recombinase and play a crucial role in the homologous recombinational repair pathway.

  11. Contributions of the RAD51 N-terminal domain to BRCA2-RAD51 interaction.

    Subramanyam, Shyamal; Jones, William T; Spies, Maria; Spies, M Ashley

    2013-10-01

    RAD51 DNA strand exchange protein catalyzes the central step in homologous recombination, a cellular process fundamentally important for accurate repair of damaged chromosomes, preservation of the genetic integrity, restart of collapsed replication forks and telomere maintenance. BRCA2 protein, a product of the breast cancer susceptibility gene, is a key recombination mediator that interacts with RAD51 and facilitates RAD51 nucleoprotein filament formation on single-stranded DNA generated at the sites of DNA damage. An accurate atomistic level description of this interaction, however, is limited to a partial crystal structure of the RAD51 core fused to BRC4 peptide. Here, by integrating homology modeling and molecular dynamics, we generated a structure of the full-length RAD51 in complex with BRC4 peptide. Our model predicted previously unknown hydrogen bonding patterns involving the N-terminal domain (NTD) of RAD51. These interactions guide positioning of the BRC4 peptide within a cavity between the core and the NTDs; the peptide binding separates the two domains and restricts internal dynamics of RAD51 protomers. The model's depiction of the RAD51-BRC4 complex was validated by free energy calculations and in vitro functional analysis of rationally designed mutants. All generated mutants, RAD51(E42A), RAD51(E59A), RAD51(E237A), RAD51(E59A/E237A) and RAD51(E42A/E59A/E237A) maintained basic biochemical activities of the wild-type RAD51, but displayed reduced affinities for the BRC4 peptide. Strong correlation between the calculated and experimental binding energies confirmed the predicted structure of the RAD51-BRC4 complex and highlighted the importance of RAD51 NTD in RAD51-BRCA2 interaction. PMID:23935068

  12. Preparation structure and dielectric behaviour of the system Sr1-LaTi1-FeO3( ≤ 0.50)

    Om Parkash; Devendra Kumar; C C Christopher

    2003-10-01

    Formation of solid solution has been explored in the valence compensated perovskite oxide system Sr1-LaTi1-FeO3 ( ≤ 0.50). XRD studies indicate the formation of solid solution for the whole range investigated. All the compositions synthesised have cubic structure similar to undoped SrTiO3. Study of dielectric behaviour of these materials show that orientational polarisation and space charge polarisation contribute significantly to it.

  13. Regulation of Rad51-Mediated Homologous Recombination by BRCA2, DSS1 and RAD52

    Rants, Louise Olthaver Juhl

    involved with the proteasome. In U. maydis, the Rad52 orthologue seems relegated to a less prominent role than in Saccharomyces cerevisiae, similar to what is found in human cells. We find that Rad52 functionally overlaps with Brh2-ΔNBD, and Rad52 colocalizes with both Brh2 and Rfa1 (subunit of RPA) in...

  14. Mutations in yeast Rad51 that partially bypass the requirement for Rad55 and Rad57 in DNA repair by increasing the stability of Rad51–DNA complexes

    Fortin, Gary S.; Symington, Lorraine S.

    2004-01-01

    Yeast Rad51 promotes homologous pairing and strand exchange in vitro, but this activity is inefficient in the absence of the accessory proteins, RPA, Rad52, Rad54 and the Rad55–Rad57 heterodimer. A class of rad51 alleles was isolated that suppresses the requirement for RAD55 and RAD57 in DNA repair, but not the other accessory factors. Five of the six mutations isolated map to the region of Rad51 that by modeling with RecA corresponds to one of the DNA-binding sites. The other mutation is in ...

  15. Physical mapping and cloning of RAD56

    Mathiasen, David P; Gallina, Irene; Germann, Susanne Manuela;

    2013-01-01

    Here we report the physical mapping of the rad56-1 mutation to the NAT3 gene, which encodes the catalytic subunit of the NatB N-terminal acetyltransferase in Saccharomyces cerevisiae. Mutation of RAD56 causes sensitivity to X-rays, methyl methanesulfonate, zeocin, camptothecin and hydroxyurea, bu...

  16. RAD51AP2, a novel vertebrate- and meiotic-specific protein, sharesa conserved RAD51-interacting C-terminal domain with RAD51AP1/PIR51

    Kovalenko, Oleg V.; Wiese, Claudia; Schild, David

    2006-07-25

    Many interacting proteins regulate and/or assist the activities of RAD51, a recombinase which plays a critical role in both DNA repair and meiotic recombination. Yeast two-hybrid screening of a human testis cDNA library revealed a new protein, RAD51AP2 (RAD51 Associated Protein 2), that interacts strongly with RAD51. A full-length cDNA clone predicts a novel vertebrate specific protein of 1159 residues, and the RAD51AP2 transcript was observed only in meiotic tissue (i.e. adult testis and fetal ovary), suggesting a meiotic-specific function for RAD51AP2. In HEK293 cells the interaction of RAD51 with an ectopically-expressed recombinant large fragment of RAD51AP2 requires the C-terminal 57 residues of RAD51AP2. This RAD51-binding region shows 81% homology to the C-terminus of RAD51AP1/PIR51, an otherwise totally unrelated RAD51-binding partner that is ubiquitously expressed. Analyses using truncations and point mutations in both RAD51AP1 and RAD51AP2 demonstrate that these proteins use the same structural motif for RAD51 binding. RAD54 shares some homology with this RAD51-binding motif, but this homologous region plays only an accessory role to the adjacent main RAD51-interacting region, which has been narrowed here to 40 amino acids. A novel protein, RAD51AP2, has been discovered that interacts with RAD51 through a C-terminal motif also present in RAD51AP1.

  17. Synergistic interactions between RAD5, RAD16, and RAD54, three partially homologous yeast DNA repair genes each in a different repair pathway

    Considerable homology has recently been noted between the proteins encoded by the RAD5, RAD16 and RAD54 genes of Saccharomyces cerevisiae. These genes are members of the RAD6, RAD3 and RAD50 epistasis groups, respectively, which correspond to the three major DNA repair pathways in yeast. These proteins also share homology with other eucaryotic proteins, including those encoded by SNF2 and MO1 of yeast, brahma and lodestar of Drosophila and the human ERCC6 gene. The homology shares features with known helicases, suggesting a newly identified helicase subfamily. We have constructed a series of congenic single-, double- and triple-deletion mutants involving RAD5, RAD16 and RAD54 to examine the interactions between these genes. Each deletion mutation alone has only a moderate effect on survival after exposure to UV radiation. Each pairwise-double mutant exhibits marked synergism. The triple-deletion mutant displays further synergism. These results confirm the assignment of the RAD54 gene to the RAD50 epistasis group and suggest that the RAD16 gene plays a larger role in DNA repair after exposure to UV radiation than has been suggested previously. Additionally, the proteins encoded by RAD5, RAD16, and RAD54 may compete for the same substrate after damage induced by UV radiation, possibly at an early step in their respective pathways. 49 refs., 6 figs., 2 tabs

  18. RAD51B in Familial Breast Cancer

    Pelttari, Liisa M.

    2016-01-01

    Common variation on 14q24.1, close to RAD51B, has been associated with breast cancer: rs999737 and rs2588809 with the risk of female breast cancer and rs1314913 with the risk of male breast cancer. The aim of this study was to investigate the role of RAD51B variants in breast cancer predisposition, particularly in the context of familial breast cancer in Finland. We sequenced the coding region of RAD51B in 168 Finnish breast cancer patients from the Helsinki region for identification of possi...

  19. RadNet Air Quality (Deployable) Data

    U.S. Environmental Protection Agency — RadNet Deployable Monitoring is designed to collect radiological and meteorological information and data asset needed to establish the impact of radiation levels on...

  20. Evidence of phase separation in Nd1-xSrxMnO3 (x=0.50,0.51,0.52,0.53,0.54,0.55)

    鲁毅; 李庆安; 邸乃力; 李润伟; 马骁; 寇志起; 成昭华

    2003-01-01

    The temperature dependence of Mn ion magnetization and the conductivity difference versus temperature provide phase separation evidence in Nd1-xSrxMnOs (x=0.50, 0.51, 0.52, 0.53, 0.54, 0.55). This is different from other reports and may suggest that a fully charge-ordered state exists in quite a narrow range; the sample preparation procedure affects the charge ordering. The polaron effect also plays an important role in explaining the conductivity.

  1. Pediatric meuroblastoma: postoperative radiation therapy using less than 2000 rad

    There is considerable controversy regarding the role of radiaiton therapy in the treatment of neuroblastoma. Postoperative irradiation in the range of 2500-4000 rad is commonly used in the treatment of Evans Stage II or III disease, but there are no data in the literature to suggest the optimum dose of radiation that is necessary. Because much lower doses have been used at the University of Florida, a retrospective study was undertaken in an attempt to determine the optimum dose necessary in conjunction with surgery. From March 1964 through July 1979, 21 children with Stage II or III neuroblastoma were seen at the University of Florida. One patient died postoperatively. The remainder received postoperative irradiation with doses ranging from 900 to 4500 rad. The lower dose of radiation used did not adversely influence survival, particularly for patients less than two years of age diagnosis. In this group, no patient had a local recurrence or died of disease, even though nine of 15 available patients received doses of 900-1500 rad

  2. Pediatric meuroblastoma: postoperative radiation therapy using less than 2000 rad

    Jacobson, H.M.; Marcus, R.B. Jr; Thar, T.L.; Million, R.R.; Graham-Pole, J.R.; Talbert, J.L.

    1983-04-01

    There is considerable controversy regarding the role of radiaiton therapy in the treatment of neuroblastoma. Postoperative irradiation in the range of 2500-4000 rad is commonly used in the treatment of Evans Stage II or III disease, but there are no data in the literature to suggest the optimum dose of radiation that is necessary. Because much lower doses have been used at the University of Florida, a retrospective study was undertaken in an attempt to determine the optimum dose necessary in conjunction with surgery. From March 1964 through July 1979, 21 children with Stage II or III neuroblastoma were seen at the University of Florida. One patient died postoperatively. The remainder received postoperative irradiation with doses ranging from 900 to 4500 rad. The lower dose of radiation used did not adversely influence survival, particularly for patients less than two years of age diagnosis. In this group, no patient had a local recurrence or died of disease, even though nine of 15 available patients received doses of 900-1500 rad.

  3. RadConEd: A Graphical Data Editor for the Radiological Consequences Model, RadCon

    This document describes the application, RadConEd, which has been designed and implemented to enable users of the RadCon system to update these parameter files. The RadCon system is written in the Java programming language, and as such provides portability across computer platforms. The software described in this report was developed in line with the portability requirements of RadCon, thus providing a uniform user interface across computer platforms and bypassing the need of using system editors. In addition a number of data integrity measures were implemented

  4. RadCon: A Radiological Consequences Model

    RadCon estimates the dose received by user selected groups in the population from an accidental release of radionuclides to the environment. The exposure pathways considered are external exposure from the cloud and ground and internal exposure from inhalation and ingestion of contaminated food. Atmospheric dispersion modelling is carried out externally to RadCon.Given a two dimensional time varying air and ground concentration of radioactive elements, RadCon allows the user to: view the air and ground concentration over the affected area, select optional parameters and calculate the dose to people,display the results to the user, and change the parameter values. RadCon offers two user interfaces: 1) the standard graphical user interface which is started using Java DoseApp at the command line, or by setting up a shortcut to this command (particularly when RadCon is installed on a PC) and 2) the text based interface used to generate information for the model inter-comparison exercise . This is initiated using Java BIOMASS at the command line, or an equivalent shortcut. The text based interface was developed for research purposes and is not generally available. Appendices A, B and C provide a summary of instructions on setting up RadCon. This will generally be carried out by the computer support personnel

  5. Analysis list: Rad23b [Chip-atlas[Archive

    Full Text Available Rad23b Pluripotent stem cell + mm9 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Rad2...3b.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Rad23b.5.tsv http://dbarchive.biosc...iencedbc.jp/kyushu-u/mm9/target/Rad23b.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Rad23b.Plu

  6. ezRAD: a simplified method for genomic genotyping in non-model organisms

    Robert J. Toonen

    2013-11-01

    Full Text Available Here, we introduce ezRAD, a novel strategy for restriction site–associated DNA (RAD that requires little technical expertise or investment in laboratory equipment, and demonstrate its utility for ten non-model organisms across a wide taxonomic range. ezRAD differs from other RAD methods primarily through its use of standard Illumina TruSeq library preparation kits, which makes it possible for any laboratory to send out to a commercial genomic core facility for library preparation and next-generation sequencing with virtually no additional investment beyond the cost of the service itself. This simplification opens RADseq to any lab with the ability to extract DNA and perform a restriction digest. ezRAD also differs from others in its flexibility to use any restriction enzyme (or combination of enzymes that cuts frequently enough to generate fragments of the desired size range, without requiring the purchase of separate adapters for each enzyme or a sonication step, which can further decrease the cost involved in choosing optimal enzymes for particular species and research questions. We apply this method across a wide taxonomic diversity of non-model organisms to demonstrate the utility and flexibility of our approach. The simplicity of ezRAD makes it particularly useful for the discovery of single nucleotide polymorphisms and targeted amplicon sequencing in natural populations of non-model organisms that have been historically understudied because of lack of genomic information.

  7. Determination of radon concentration in water using RAD7 with RAD H2O accessories

    In the last decade, the radon issue has become one of the major problems of radiation protection. Radon exposure occurs when using water for showering, washing dishes, cooking and drinking water. RAD7 and Rad H20 accessories were used in order to measure radon concentration in water sample. In this study, four types of water were concerns which are reverse osmosis (drinking water), mineral water, tap water and well water. Reverse osmosis (drinking water) and mineral water were bought from the nearest supermarket while tap water and well water were taken from selected areas of Pulau Pinang and Kedah. Total 20 samples were taken with 5 samples for each type of water. The measured radon concentration ranged from 2.9±2.9 to 79.5±17 pCi/L, 2.9±2.9 to 67.8±16 pCi/L, 15.97±7 to 144.25±24 pCi/L and 374.89±37 to 6409.03±130 pCi/L in reverse osmosis (drinking water), mineral water, tap water and well water. Well water has the highest radon compared to others. It was due to their geological element such as granite. Results for all types of water are presented and compared with maximum contamination limit (MCL) recommended by United State Environmental Protection Agency (USEPA) which is 300pCi/L. Reverse osmosis water, mineral water and tap water were fall below MCL. However, well water was exceeded maximum level that was recommended. Thus, these findings were suggested that an action should be taken to reduce radon concentration level in well water as well as reduce a health risk towards the public

  8. MSL-RAD radiation environment measurements.

    Guo, Jingnan; Zeitlin, Cary; Wimmer-Schweingruber, Robert F; Hassler, Donald M; Ehresmann, Bent; Köhler, Jan; Böhm, Eckart; Böttcher, Stephan; Brinza, David; Burmeister, Sönke; Cucinotta, Francis; Martin, Cesar; Posner, Arik; Rafkin, Scot; Reitz, Guenther

    2015-09-01

    In this study, results are presented from the on-board radiation assessment detector (RAD) of Mars Science Laboratory (MSL). RAD is designed to measure the energetic particle radiation environment, which consists of galactic cosmic rays (GCRs) and solar energetic particles (SEPs) as well as secondary particles created by nuclear interactions of primary particles in the shielding (during cruise) or Martian soil and atmosphere (surface measurements). During the cruise, RAD collected data on space radiation from inside the craft, thus allowing for a reasonable estimation of what a human crew travelling to/from Mars might be exposed to. On the surface of Mars, RAD is shielded by the atmosphere (from above) and the planet itself (from below). RAD measures the first detailed radiation data from the surface of another planet, and they are highly relevant for planning future crewed missions. The results for radiation dose and dose equivalent (a quantity most directly related to human health risk) are presented during the cruise phase, as well as on the Martian surface. Dose and dose equivalent are dominated by the continuous GCR radiation, but several SEP events were also detected and are discussed here. PMID:25969529

  9. Radiological information management system (RadIMS)

    Westinghouse Idaho Nuclear Company, Inc. (WINCO) is developing and implementing an information management system, known as RadIMS, to track and record personnel exposure to ionizing radiation. RadIMS has been designed to fulfill all the requirements of US Department of Energy (USDOE) Order 5480.11, ''Radiation Protection for Occupational Workers.'' This Order requires the contractor to maintain detailed radiation exposure records on all individuals who work at the facility. These records must be retrievable for the entire working life of the individual and be available to other USDOE contractors on request. To meet these general needs, RadIMS provides for retrieval of detailed, comprehensive individual exposure histories as well as the usual online interactions to accomplish day-today radiation protection operations. These two extremes of functionality require different approaches in the WINCO computing environment. The exposure histories include database text, paper, microfilm, and electronic bitmaps

  10. Rietveld refinements of the solid solution Li(1-2x)Ni xTiO(PO4) (0 ≤ x ≤ 0.50)

    Li(1-2x)Ni xTiO(PO4) oxyphosphates with 0 ≤ x ≤ 0.10 crystallize in the orthorhombic system with the space group Pnma, those with 0.10 1/c and compositions with 0.25 0.50Ni0.25TiO(PO4) and Ni0.50TiO(PO4). The structure of the compositions 0 ≤ x ≤ 0.25 is based on a three-dimensional anionic framework constructed of chains of alternating TiO6 octahedra and PO4 tetrahedra, with the lithium and nickel atoms in the cavities in the framework. The dominant structural units in the compositions are chains of tilted corner-sharing TiO6 octahedra running parallel to one of the axis. The oxygen atoms of the shared corners, not implied in (PO4) tetrahedra, justify the oxyphosphate designation. Titanium atoms are displaced from the geometrical center of the octahedra resulting in alternating long (∼2.25 A) and short (∼1.71 A) Ti-O(1) bonds. The four remaining Ti-O bond distances have intermediate values ranging from 1.91 to 2.06 A

  11. Evaluation of COTS Rad Detection Apps

    Wagner, Eric [National Security Technologies, LLC. (NSTec), Mercury, NV (United States)

    2014-02-01

    Mobile applications are currently under distribution to smart phones utilizing the built-in charge coupled-device (CCD) camera as a radiation detector. The CCD detector has a very low but measurable gamma interaction cross section so the mechanism is feasible, especially for higher dose rate environments. Given that in a large release of radioactive material these ‘crowd sourced’ measurements will be put forth for consideration, a testing and evaluation of the accuracy and uncertainty of the Apps is a critical endeavor. Not only is the accuracy of the reported measurement of concern to the immediate user’s safety, a quantitative uncertainty is required for a government response such as the Federal Radiological Monitoring and Assessment Center (FRMAC) to accept the values for consideration in the determination of regions exceeding protective action guidelines. Already, prompted by the Fukushima nuclear material releases, several repositories of this crowd-sourced data have been created (http://japan.failedrobot.com, http://www.stubbytour.com/nuc/index_en.asp, and http://www.rdtn.org) although the question remains as to the reliability of measurements incorporated into these repositories. In cases of conflict between the real-time published crowd-sourced data and governmental protective actions prepared literature should be on-hand documenting why the difference, if any, exists. Four applications for iOS devices were obtained along with hardware to benchmark their performance. Gamma/X-Ray Detector by Stephan Hotto, Geiger Camera by Senscare, and RadioactivityCounter App by Hotray LTD are all the applications available for distribution within the US that utilize the CCD camera sensor for detection of radiation levels. The CellRad app under development by Idaho National Laboratory for the Android platform was evaluated. In addition, iRad Geiger with the associated hardware accessory was also benchmarked. Radiation fields were generated in a Cs-137 JL Shepherd

  12. Evaluation of COTS Rad Detection Apps

    Mobile applications are currently under distribution to smart phones utilizing the built-in charge coupled-device (CCD) camera as a radiation detector. The CCD detector has a very low but measurable gamma interaction cross section so the mechanism is feasible, especially for higher dose rate environments. Given that in a large release of radioactive material these 'crowd sourced' measurements will be put forth for consideration, a testing and evaluation of the accuracy and uncertainty of the Apps is a critical endeavor. Not only is the accuracy of the reported measurement of concern to the immediate user's safety, a quantitative uncertainty is required for a government response such as the Federal Radiological Monitoring and Assessment Center (FRMAC) to accept the values for consideration in the determination of regions exceeding protective action guidelines. Already, prompted by the Fukushima nuclear material releases, several repositories of this crowd-sourced data have been created (http://japan.failedrobot.com, http://www.stubbytour.com/nuc/index_en.asp, and http://www.rdtn.org) although the question remains as to the reliability of measurements incorporated into these repositories. In cases of conflict between the real-time published crowd-sourced data and governmental protective actions prepared literature should be on-hand documenting why the difference, if any, exists. Four applications for iOS devices were obtained along with hardware to benchmark their performance. Gamma/X-Ray Detector by Stephan Hotto, Geiger Camera by Senscare, and RadioactivityCounter App by Hotray LTD are all the applications available for distribution within the US that utilize the CCD camera sensor for detection of radiation levels. The CellRad app under development by Idaho National Laboratory for the Android platform was evaluated. In addition, iRad Geiger with the associated hardware accessory was also benchmarked. Radiation fields were generated in a Cs-137 JL

  13. Fission yeast Rad52 phosphorylation restrains error prone recombination pathways.

    Bellini, Angela; Girard, Pierre-Marie; Tessier, Ludovic; Sage, Evelyne; Francesconi, Stefania

    2014-01-01

    Rad52 is a key protein in homologous recombination (HR), a DNA repair pathway dedicated to double strand breaks and recovery of blocked or collapsed replication forks. Rad52 allows Rad51 loading on single strand DNA, an event required for strand invasion and D-loop formation. In addition, Rad52 functions also in Rad51 independent pathways because of its ability to promote single strand annealing (SSA) that leads to loss of genetic material and to promote D-loops formation that are cleaved by Mus81 endonuclease. We have previously reported that fission yeast Rad52 is phosphorylated in a Sty1 dependent manner upon oxidative stress and in cells where the early step of HR is impaired because of lack of Rad51. Here we show that Rad52 is also constitutively phosphorylated in mus81 null cells and that Sty1 partially impinges on such phosphorylation. As upon oxidative stress, the Rad52 phosphorylation in rad51 and mus81 null cells appears to be independent of Tel1, Rad3 and Cdc2. Most importantly, we show that mutating serine 365 to glycine (S365G) in Rad52 leads to loss of the constitutive Rad52 phosphorylation observed in cells lacking Rad51 and to partial loss of Rad52 phosphorylation in cells lacking Mus81. Contrariwise, phosphorylation of Rad52-S365G protein is not affected upon oxidative stress. These results indicate that different Rad52 residues are phosphorylated in a Sty1 dependent manner in response to these distinct situations. Analysis of spontaneous HR at direct repeats shows that mutating serine 365 leads to an increase in spontaneous deletion-type recombinants issued from mitotic recombination that are Mus81 dependent. In addition, the recombination rate in the rad52-S365G mutant is further increased by hydroxyurea, a drug to which mutant cells are sensitive. PMID:24748152

  14. Environmental Radiation Studies Utilizing RadNet

    Jackson, Steven

    2010-03-01

    RadNet is an Environmental Protection Agency (EPA) managed environmental radiation and air quality monitoring station that has been recently installed on the Angelo State University campus. RadNet cycles air through a filter which collects particulate matter for an examination of alpha and beta activities of contained material. This project includes defining dominant alpha and beta emitters in the local environment, conducting a correlation study involving the effect of weather and wind direction on filter activity, physical interpretation of air quality index (AQI), and the use of X-ray fluorescence to verify radon decay progeny in the local environment.

  15. μSR studies on the response of spin dynamics to applying or removing magnetic field—Typical Ising spin glass Fe0.50Mn0.50TiO3

    Torikai, Eiko; Ito, Atsuko; Watanabe, Isao; Nagamine, Kanetada

    2006-03-01

    One of the distinguishing properties of spin glass (SG) systems is a long-time relaxation of magnetization below the SG transition temperature. Motivated by the interests on how the microscopic spin dynamics is related to the macroscopic behavior of spin system in the SG state, we have performed the μSR measurement for a typical Ising SG system Fe 0.50Mn 0.50TiO 3 under various experimental conditions. We also pay attention to how the spin dynamics responds to a sudden change of magnetic fields. Thus, we have discussed the spin dynamics of SG system which had not been detected before our μSR measurement. For example, we have shown that the switching-off of a magnetic field at the field-cooled state makes the spin fluctuations faster. Moreover, such spin fluctuations have shown to remain faster at least up to the order of 2 h, although the thermoremanent magnetization decays dramatically within 2 h.

  16. Nanoscale Ferroelectric Switchable Polarization and Leakage Current Behavior in (Ba0.50Sr0.50(Ti0.80Sn0.20O3 Thin Films Prepared Using Chemical Solution Deposition

    Venkata Sreenivas Puli

    2015-01-01

    Full Text Available Nanoscale switchable ferroelectric (Ba0.50Sr0.50(Ti0.80Sn0.20O3-BSTS polycrystalline thin films with a perovskite structure were prepared on Pt/TiOx/SiO2/Si substrate by chemical solution deposition. X-ray diffraction (XRD spectra indicate that a cubic perovskite crystalline structure and Raman spectra revealed that a tetragonal perovskite crystalline structure is present in the thin films. Sr2+ and Sn4+ cosubstituted film exhibited the lowest leakage current density. Piezoresponse Force Microscopy (PFM technique has been employed to acquire out-of-plane (OPP piezoresponse images and local piezoelectric hysteresis loop in polycrystalline BSTS films. PFM phase and amplitude images reveal nanoscale ferroelectric switching behavior at room temperature. Square patterns with dark and bright contrasts were written by local poling and reversible nature of the piezoresponse behavior was established. Local piezoelectric butterfly amplitude and phase hysteresis loops display ferroelectric nature at nanoscale level. The significance of this paper is to present ferroelectric/piezoelectric nature in present BSTS films at nanoscale level and corroborating ferroelectric behavior by utilizing Raman spectroscopy. Thus, further optimizing physical and electrical properties, BSTS films might be useful for practical applications which include nonvolatile ferroelectric memories, data-storage media, piezoelectric actuators, and electric energy storage capacitors.

  17. Synthesis, structure refinement and characterisation of a new oxyphosphate Mg0.50TiO(PO4)

    A new titanium oxyphosphate Mg0.50TiO(PO4) has been synthesized and characterized by several physical techniques: X-ray diffraction, 31P MAS-NMR, Raman diffusion, infrared absorption and diffuse reflectance spectroscopy. It crystallizes in the monoclinic system with unit cell parameters: a = 7.367(9), b = 7.385(8), c = 7.373(9) A, β = 120.23(1), with the space group P21/c (no. 14), Z = 4. The crystal structure has been refined by the Rietveld method using X-ray powder diffraction. The conventional R indices obtained are R wp = 0.138, R p = 0.096 and R B = 0.0459. The structure of Mg0.50TiO(PO4) consists of infinite chains of corner-shared [TiO6] octahedra parallel to the c-axis, crosslinked by corner-shared [PO4] tetrahedra. These infinite chains have alternating short (1.74 A) and long (2.26 A) Ti-O bonds and are similar to those found in titanium oxyphosphate MII0.50TiO(PO4) (M2+ = Fe2+, Co2+, Ni2+, Cu2+, Zn2+). The magnesium atom is located in an antiprism between two [TiO6] octahedra. 31P MAS NMR showed only a single 31P resonance line, in a good agreement with the crystal structure. Raman and IR spectra show strong bands respectively at 765 and 815 cm-1, attributed to the vibration of -Ti-O-Ti-O- bonds in the infinite chains. The gap due to the Oxygen-Titanium(IV) charge transfer is 3.37 eV

  18. NMR study of phase transitions in VT/sub 0.50/ and VT/sub 0.75/

    The work describes the preparation of polycrystalline VT/sub 0.50/ and VT/sub 0.75/ and observations of phase transitions using pulse nuclear magnetic resonance measurements of triton relaxation times. The critical temperatures (T/sub c/) for the phase transitions in the VT/sub x/ samples follow the mass-dependent trends found for VH/sub x/ and VD/sub x/ and qualitatively obey the isotopic dependence predicted by the theoretical models of Entin et al. 23 refs

  19. Xe-bearing hydrocarbon ions: Observation of Xe.acetylene+rad and Xe.benzene+rad radical cations and calculations of their ground state structures

    Cui, Zhong-hua; Attah, Isaac K.; Platt, Sean P.; Aziz, Saadullah G.; Kertesz, Miklos; El-Shall, M. S.

    2016-04-01

    This work reports evidence for novel types of Xe-bearing hydrocarbon radical cations. The Xe.acetylene+rad radical cation adduct is observed at nearly room temperature using the mass-selected drift cell technique. The irreversible addition of the Xe atom and the lack of back dissociation to HCCH+rad + Xe is consistent with the calculated binding energy of 0.85 eV to be contrasted with the metastable nature of the neutral Xe.acetylene adduct. The observed Xe.benzene+rad radical cation appears to be a weakly bound complex stabilized mainly by ion-induced dipole interaction consistent with a calculated binding energy in the range of 0.14-0.17 eV.

  20. HiRadMat: materials under scrutiny

    Anaïs Schaeffer

    2011-01-01

    CERN's new facility, HiRadMat (High Radiation to Materials), which is designed to test materials for the world's future particle accelerators, should be operational and welcoming its first experiments by the end of the year.   The HiRadMat facility, located in the TNC tunnel. The materials used in the LHC and its experiments are exposed to very high-energy particles. The LHC machine experts obviously didn't wait for the first collisions in the world's most powerful accelerator to put the materials through their paces - the equipment was validated following a series of stringent tests. And these tests will get even tougher now, with the arrival of HiRadMat. The tunnel that formerly housed the West Area Neutrino Facility (WANF) has been completely revamped to make way for CERN's latest facility, HiRadMat. Supported by the Radioprotection service, a team from the Engineering (EN) Department handled the dismantling operations from October 2009 to December 2010. "We could only work on disman...

  1. RadNet Air Quality (Fixed Station) Data

    U.S. Environmental Protection Agency — RadNet is a national network of monitoring stations that regularly collect air for analysis of radioactivity. The RadNet network, which has stations in each State,...

  2. Promotion of Homologous Recombination and Genomic Stability byRAD51AP1 via RAD51 Recombinase Enhancement

    Wiese, Claudia; Dray, Eloise; Groesser, Torsten; San Filippo,Joseph; Shi, Idina; Collins, David W.; Tsai, Miaw-Sheue; Williams,Gareth; Rydberg, Bjorn; Sung, Patrick; Schild, David

    2007-04-11

    Homologous recombination (HR) repairs chromosome damage and is indispensable for tumor suppression in humans. RAD51 mediates the DNA strand pairing step in HR. RAD51AP1 (RAD51 Associated Protein 1) is a RAD51-interacting protein whose function has remained elusive. Knockdown of RAD51AP1 in human cells by RNA interference engenders sensitivity to different types of genotoxic stress. Moreover, RAD51AP1-depleted cells are impaired for the recombinational repair of a DNA double-strand break and exhibit chromatid breaks both spontaneously and upon DNA damaging treatment. Purified RAD51AP1 binds dsDNA and RAD51, and it greatly stimulates the RAD51-mediated D-loop reaction. Biochemical and cytological results show that RAD51AP1 functions at a step subsequent to the assembly of the RAD51-ssDNA nucleoprotein filament. Our findings provide the first evidence that RAD51AP1 helps maintain genomic integrity via RAD51 recombinase enhancement.

  3. Karyotype rearrangements in a wine yeast strain by rad52-dependent and rad52-independent mechanisms

    Carro, David; Bartra, Enric; Piña, Benjamín

    2003-01-01

    Yeast strains isolated from the wild may undergo karyotype changes during vegetative growth, a characteristic that compromises their utility in genetic improvement projects for industrial purposes. Karyotype instability is a dominant trait, segregating among meiotic derivatives as if it depended upon only a few genetic elements. We show that disrupting the RAD52 gene in a hypervariable strain partially stabilizes its karyotype. Specifically, RAD52 disruption eliminated recombination at telome...

  4. Co-expression with RadA and the characterization of stRad55B, a RadA paralog from the hyperthermophilic crenarchaea Sulfolobus tokodaii

    2008-01-01

    ST0838 (designed stRad55B) is one of the four RadA paralogs (or Rad55 homologues) in the genome of the hyperthermophilic crenarchaeon Sulfolobus tokodaii. The gene is induced by UV irradiation, suggesting that it is involved in DNA recombinational repair in this organism. However, this protein could not be expressed normally in vitro. In this study, thermostable and soluble stRad55B was obtained by co-expression with S. tokodaii RadA (stRadA) in E. coli, and the enzymatic properties were examined. It was found that stRad55B bound ssDNA preferentially and had a very weak ATPase activity that was not stimulated by DNA. The recombinant protein inhibited the strand exchange activity promoted by stRadA, indicating that stRad55B might be an inhibitor to the homologous recombination in this archaeon. The results will be helpful for further functional and interaction analysis of RadA paralogs and for the understanding of the mechanism of recombinational repair in archaea.

  5. Contribution of Germline Mutations in the RAD51B, RAD51C, and RAD51D Genes to Ovarian Cancer in the Population

    Song, Honglin; Dicks, Ed; Ramus, Susan J; Tyrer, Jonathan P; Intermaggio, Maria P; Hayward, Jane; Edlund, Christopher K; Conti, David; Harrington, Patricia; Fraser, Lindsay; Philpott, Susan; Anderson, Christopher; Rosenthal, Adam; Gentry-Maharaj, Aleksandra; Bowtell, David D; Alsop, Kathryn; Cicek, Mine S; Cunningham, Julie M; Fridley, Brooke L; Alsop, Jennifer; Jimenez-Linan, Mercedes; Høgdall, Estrid; Høgdall, Claus K; Jensen, Allan; Kjaer, Susanne Krüger; Lubiński, Jan; Huzarski, Tomasz; Jakubowska, Anna; Gronwald, Jacek; Poblete, Samantha; Lele, Shashi; Sucheston-Campbell, Lara; Moysich, Kirsten B; Odunsi, Kunle; Goode, Ellen L; Menon, Usha; Jacobs, Ian J; Gayther, Simon A; Pharoah, Paul D P

    2015-01-01

    PURPOSE: The aim of this study was to estimate the contribution of deleterious mutations in the RAD51B, RAD51C, and RAD51D genes to invasive epithelial ovarian cancer (EOC) in the population and in a screening trial of individuals at high risk of ovarian cancer. PATIENTS AND METHODS: The coding...... sequence and splice site boundaries of the three RAD51 genes were sequenced and analyzed in germline DNA from a case-control study of 3,429 patients with invasive EOC and 2,772 controls as well as in 2,000 unaffected women who were BRCA1/BRCA2 negative from the United Kingdom Familial Ovarian Cancer...... (RAD51C, n = 7; RAD51D, n = 5; and RAD51B, n = 1), which was a significantly greater rate than in controls (P < .001); furthermore, RAD51 mutation carriers were more likely than noncarriers to have a family history of ovarian cancer (P < .001). CONCLUSION: These results confirm that RAD51C and RAD51D...

  6. Co-expression with RadA and the characterization of stRad55B, a RadA paralog from the hyperthermophilic crenarchaea Sulfolobus tokodaii

    2008-01-01

    ST0838 (designed stRad55B) is one of the four RadA paralogs (or Rad55 homologues) in the genome of the hyperthermophilic crenarchaeon Sulfolobus tokodaii. The gene is induced by UV irradiation, sug-gesting that it is involved in DNA recombinational repair in this organism. However, this protein could not be expressed normally in vitro. In this study, thermostable and soluble stRad55B was obtained by co-expression with S. tokodaii RadA (stRadA) in E. coli, and the enzymatic properties were examined. It was found that stRad55B bound ssDNA preferentially and had a very weak ATPase activity that was not stimulated by DNA. The recombinant protein inhibited the strand exchange activity promoted by stRadA, indicating that stRad55B might be an inhibitor to the homologous recombination in this ar-chaeon. The results will be helpful for further functional and interaction analysis of RadA paralogs and for the understanding of the mechanism of recombinational repair in archaea.

  7. Inter-subunit interactions that coordinate Rad51's activities

    A.A. Grigorescu (Arabela); J.H.A. Vissers (Joseph); D. Ristic (Dejan); Y.Z. Pigli (Ying); T.W. Lynch (Thomas); C. Wyman (Claire); P.A. Rice (Phoebe)

    2009-01-01

    textabstractRad51 is the central catalyst of homologous recombination in eukaryotes and is thus critical for maintaining genomic integrity. Recent crystal structures of filaments formed by Rad51 and the closely related archeal RadA and eubacterial RecA proteins place the ATPase site at the protomeri

  8. RAD51B in Familial Breast Cancer

    Pelttari, Liisa M.; Khan, Sofia; Vuorela, Mikko; Kiiski, Johanna I.; Vilske, Sara; Nevanlinna, Viivi; Ranta, Salla; Schleutker, Johanna; Winqvist, Robert; Kallioniemi, Anne; Dörk, Thilo; Bogdanova, Natalia V.; Figueroa, Jonine; Pharoah, Paul D. P.; Schmidt, Marjanka K.; Dunning, Alison M.; García-Closas, Montserrat; Bolla, Manjeet K.; Dennis, Joe; Michailidou, Kyriaki; Wang, Qin; Hopper, John L.; Southey, Melissa C.; Rosenberg, Efraim H.; Fasching, Peter A.; Beckmann, Matthias W.; Peto, Julian; dos-Santos-Silva, Isabel; Sawyer, Elinor J.; Tomlinson, Ian; Burwinkel, Barbara; Surowy, Harald; Guénel, Pascal; Truong, Thérèse; Bojesen, Stig E.; Nordestgaard, Børge G.; Benitez, Javier; González-Neira, Anna; Neuhausen, Susan L.; Anton-Culver, Hoda; Brenner, Hermann; Arndt, Volker; Meindl, Alfons; Schmutzler, Rita K.; Brauch, Hiltrud; Brüning, Thomas; Lindblom, Annika; Margolin, Sara; Mannermaa, Arto; Hartikainen, Jaana M.; Chenevix-Trench, Georgia; Van Dyck, Laurien; Janssen, Hilde; Chang-Claude, Jenny; Rudolph, Anja; Radice, Paolo; Peterlongo, Paolo; Hallberg, Emily; Olson, Janet E.; Giles, Graham G.; Milne, Roger L.; Haiman, Christopher A.; Schumacher, Fredrick; Simard, Jacques; Dumont, Martine; Kristensen, Vessela; Borresen-Dale, Anne-Lise; Zheng, Wei; Beeghly-Fadiel, Alicia; Grip, Mervi; Andrulis, Irene L.; Glendon, Gord; Devilee, Peter; Seynaeve, Caroline; Hooning, Maartje J.; Collée, Margriet; Cox, Angela; Cross, Simon S.; Shah, Mitul; Luben, Robert N.; Hamann, Ute; Torres, Diana; Jakubowska, Anna; Lubinski, Jan; Couch, Fergus J.; Yannoukakos, Drakoulis; Orr, Nick; Swerdlow, Anthony; Darabi, Hatef; Li, Jingmei; Czene, Kamila; Hall, Per; Easton, Douglas F.; Mattson, Johanna; Blomqvist, Carl; Aittomäki, Kristiina; Nevanlinna, Heli

    2016-01-01

    Common variation on 14q24.1, close to RAD51B, has been associated with breast cancer: rs999737 and rs2588809 with the risk of female breast cancer and rs1314913 with the risk of male breast cancer. The aim of this study was to investigate the role of RAD51B variants in breast cancer predisposition, particularly in the context of familial breast cancer in Finland. We sequenced the coding region of RAD51B in 168 Finnish breast cancer patients from the Helsinki region for identification of possible recurrent founder mutations. In addition, we studied the known rs999737, rs2588809, and rs1314913 SNPs and RAD51B haplotypes in 44,791 breast cancer cases and 43,583 controls from 40 studies participating in the Breast Cancer Association Consortium (BCAC) that were genotyped on a custom chip (iCOGS). We identified one putatively pathogenic missense mutation c.541C>T among the Finnish cancer patients and subsequently genotyped the mutation in additional breast cancer cases (n = 5259) and population controls (n = 3586) from Finland and Belarus. No significant association with breast cancer risk was seen in the meta-analysis of the Finnish datasets or in the large BCAC dataset. The association with previously identified risk variants rs999737, rs2588809, and rs1314913 was replicated among all breast cancer cases and also among familial cases in the BCAC dataset. The most significant association was observed for the haplotype carrying the risk-alleles of all the three SNPs both among all cases (odds ratio (OR): 1.15, 95% confidence interval (CI): 1.11–1.19, P = 8.88 x 10−16) and among familial cases (OR: 1.24, 95% CI: 1.16–1.32, P = 6.19 x 10−11), compared to the haplotype with the respective protective alleles. Our results suggest that loss-of-function mutations in RAD51B are rare, but common variation at the RAD51B region is significantly associated with familial breast cancer risk. PMID:27149063

  9. RAD51B in Familial Breast Cancer.

    Liisa M Pelttari

    Full Text Available Common variation on 14q24.1, close to RAD51B, has been associated with breast cancer: rs999737 and rs2588809 with the risk of female breast cancer and rs1314913 with the risk of male breast cancer. The aim of this study was to investigate the role of RAD51B variants in breast cancer predisposition, particularly in the context of familial breast cancer in Finland. We sequenced the coding region of RAD51B in 168 Finnish breast cancer patients from the Helsinki region for identification of possible recurrent founder mutations. In addition, we studied the known rs999737, rs2588809, and rs1314913 SNPs and RAD51B haplotypes in 44,791 breast cancer cases and 43,583 controls from 40 studies participating in the Breast Cancer Association Consortium (BCAC that were genotyped on a custom chip (iCOGS. We identified one putatively pathogenic missense mutation c.541C>T among the Finnish cancer patients and subsequently genotyped the mutation in additional breast cancer cases (n = 5259 and population controls (n = 3586 from Finland and Belarus. No significant association with breast cancer risk was seen in the meta-analysis of the Finnish datasets or in the large BCAC dataset. The association with previously identified risk variants rs999737, rs2588809, and rs1314913 was replicated among all breast cancer cases and also among familial cases in the BCAC dataset. The most significant association was observed for the haplotype carrying the risk-alleles of all the three SNPs both among all cases (odds ratio (OR: 1.15, 95% confidence interval (CI: 1.11-1.19, P = 8.88 x 10-16 and among familial cases (OR: 1.24, 95% CI: 1.16-1.32, P = 6.19 x 10-11, compared to the haplotype with the respective protective alleles. Our results suggest that loss-of-function mutations in RAD51B are rare, but common variation at the RAD51B region is significantly associated with familial breast cancer risk.

  10. A Statistical Analysis of Laser Ablated Ba(Sub 0.50)Sr(Sub 0.50)TiO(Sub 3)/LaAlO(Sub 3) Films for Microwave Applications

    Romanofsky, R. R.; Varaljay, N. C.; Alterovitz, S. A.; Miranda, F. A.; Mueller, C. M.; VanKeuls, F. W.; Kim, J.; Harshavardhan, K. S.

    2002-01-01

    The NASA Glenn Research Center is constructing a 616 element scanning phased array antenna using thin film Ba(sub x)Sr(sub 1-x)TiO(sub 3) based phase shifters. A critical milestone is the production of 616 identical phase shifters at 19 GHz with [asymptotically equal to]4 dB insertion loss and at least 337.5 deg phase shift with 3 percent bandwidth. It is well known that there is a direct relationship between dielectric tuning and loss due to the Kramers-Kronig relationship and that film crystallinity and strain, affected by the substrate template, play an important role. Ba(sub 0.50)Sr(sub 0.50)TiO (sub 3) films, nominally 400 nm thick, were deposited on 48 0.25 mm thick, 5 cm diameter LaAlO(sub 3) wafers. Although previous results suggested that Mn-doped films on MgO were intrinsically superior in terms of phase shift per unit loss, for this application phase shift per unit length was more important. The composition was selected as a compromise between tuning and loss for room temperature operation (e.g. crystallinity progressively degrades for Ba concentrations in excess of 30 percent). As a prelude to fabricating the array, it was necessary to process, screen, and inventory a large number of samples. Variable angle ellipsometry was used to characterize refractive index and film thickness across each wafer. Microstructural properties of the thin films were characterized using high resolution X-ray diffractometry. Finally, prototype phase shifters and resonators were patterned on each wafer and RE probed to measure tuning as a function of dc bias voltage as well as peak (0 field) permittivity and unloaded Q. The relationship among film quality and uniformity and performance is analyzed. This work presents the first statistically relevant study of film quality and microwave performance and represents a milestone towards commercialization of thin ferroelectric films for microwave applications.

  11. Dose Calibration of the ISS-RAD Fast Neutron Detector

    Zeitlin, C.

    2015-01-01

    The ISS-RAD instrument has been fabricated by Southwest Research Institute and delivered to NASA for flight to the ISS in late 2015 or early 2016. ISS-RAD is essentially two instruments that share a common interface to ISS. The two instruments are the Charged Particle Detector (CPD), which is very similar to the MSL-RAD detector on Mars, and the Fast Neutron Detector (FND), which is a boron-loaded plastic scintillator with readout optimized for the 0.5 to 10 MeV energy range. As the FND is completely new, it has been necessary to develop methodology to allow it to be used to measure the neutron dose and dose equivalent. This talk will focus on the methods developed and their implementation using calibration data obtained in quasi-monoenergetic (QMN) neutron fields at the PTB facility in Braunschweig, Germany. The QMN data allow us to determine an approximate response function, from which we estimate dose and dose equivalent contributions per detected neutron as a function of the pulse height. We refer to these as the "pSv per count" curves for dose equivalent and the "pGy per count" curves for dose. The FND is required to provide a dose equivalent measurement with an accuracy of ?10% of the known value in a calibrated AmBe field. Four variants of the analysis method were developed, corresponding to two different approximations of the pSv per count curve, and two different implementations, one for real-time analysis onboard ISS and one for ground analysis. We will show that the preferred method, when applied in either real-time or ground analysis, yields good accuracy for the AmBe field. We find that the real-time algorithm is more susceptible to chance-coincidence background than is the algorithm used in ground analysis, so that the best estimates will come from the latter.

  12. CRED Subsurface Temperature Recorder (STR); NWHI, MID; Long: -177.32334, Lat: 28.24437 (WGS84); Sensor Depth: 0.50m; Data Range: 20030729-20041001.

    National Oceanic and Atmospheric Administration, Department of Commerce — Data from Coral Reef Ecosystem Division (CRED), NOAA Pacific Islands Fisheries Science Center (PIFSC) Subsurface Temperature Recorders (STR) provide a time series...

  13. Analysis list: RAD21 [Chip-atlas[Archive

    Full Text Available ncedbc.jp/kyushu-u/hg19/target/RAD21.1.tsv http://dbarchive.biosciencedbc.jp/kyushu...-u/hg19/target/RAD21.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/RAD21.10.tsv http://dbarchive.bioscience...dbc.jp/kyushu-u/hg19/colo/RAD21.Blood.tsv,http://dbarchive.bioscience...dbc.jp/kyushu-u/hg19/colo/RAD21.Breast.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/RAD21.Dige...stive_tract.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/RAD21.Liver.tsv,http://dbarchive.bioscience

  14. Monte Carlo calculation of the energy response characteristics of a RadFET radiation detector

    The Metal -Oxide Semiconductor Field-Effect-Transistor (MOSFET, RadFET) is frequently used as a sensor of ionizing radiation in nuclear-medicine, diagnostic-radiology, radiotherapy quality-assurance and in the nuclear and space industries. We focused our investigations on calculating the energy response of a p-type RadFET to low-energy photons in range from 12 keV to 2 MeV and on understanding the influence of uncertainties in the composition and geometry of the device in calculating the energy response function. All results were normalized to unit air kerma incident on the RadFET for incident photon energy of 1.1 MeV. The calculations of the energy response characteristics of a RadFET radiation detector were performed via Monte Carlo simulations using the MCNPX code and for a limited number of incident photon energies the FOTELP code was also used for the sake of comparison. The geometry of the RadFET was modeled as a simple stack of appropriate materials. Our goal was to obtain results with statistical uncertainties better than 1% (fulfilled in MCNPX calculations for all incident energies which resulted in simulations with 1 - 2x109 histories.

  15. Sturgeon conservation genomics: SNP discovery and validation using RAD sequencing.

    Ogden, R; Gharbi, K; Mugue, N; Martinsohn, J; Senn, H; Davey, J W; Pourkazemi, M; McEwing, R; Eland, C; Vidotto, M; Sergeev, A; Congiu, L

    2013-06-01

    Caviar-producing sturgeons belonging to the genus Acipenser are considered to be one of the most endangered species groups in the world. Continued overfishing in spite of increasing legislation, zero catch quotas and extensive aquaculture production have led to the collapse of wild stocks across Europe and Asia. The evolutionary relationships among Adriatic, Russian, Persian and Siberian sturgeons are complex because of past introgression events and remain poorly understood. Conservation management, traceability and enforcement suffer a lack of appropriate DNA markers for the genetic identification of sturgeon at the species, population and individual level. This study employed RAD sequencing to discover and characterize single nucleotide polymorphism (SNP) DNA markers for use in sturgeon conservation in these four tetraploid species over three biological levels, using a single sequencing lane. Four population meta-samples and eight individual samples from one family were barcoded separately before sequencing. Analysis of 14.4 Gb of paired-end RAD data focused on the identification of SNPs in the paired-end contig, with subsequent in silico and empirical validation of candidate markers. Thousands of putatively informative markers were identified including, for the first time, SNPs that show population-wide differentiation between Russian and Persian sturgeons, representing an important advance in our ability to manage these cryptic species. The results highlight the challenges of genotyping-by-sequencing in polyploid taxa, while establishing the potential genetic resources for developing a new range of caviar traceability and enforcement tools. PMID:23473098

  16. Two isoforms of plant RAD23 complement a UV-sensitive rad23 mutant in yeast

    DNA repair by nucleotide excision (NER) has been demonstrated in plant cells at the biochemical level but until now none of the molecular components of the plant NER complex has been identified. In this paper, the cloning and characterization of two isoforms of RAD23 from carrot (Daucus carota L.) are reported. It has been suggested that RAD23 in yeast is an assembly factor of the NER complex required for transcription-coupled repair as well as efficient overall genome repair. A functional assay demonstrated that both plant homologues complement the UV-sensitive phenotype of a rad23 deletion mutant of yeast. This result suggests that homologous polypeptides may catalyse NER in plants and yeast and, possibly, by a similar mechanism

  17. Inter-observer variability within BI-RADS and RANZCR mammographic density assessment schemes

    Damases, Christine N.; Mello-Thoms, Claudia; McEntee, Mark F.

    2016-03-01

    This study compares variability associated with two visual mammographic density (MD) assessment methods using two separate samples of radiologists. The image test-set comprised of images obtained from 20 women (age 42-89 years). The images were assessed for their MD by twenty American Board of Radiology (ABR) examiners and twenty-six radiologists registered with the Royal Australian and New Zealand College of Radiologists (RANZCR). Images were assessed using the same technology and conditions, however the ABR radiologists used the BI-RADS and the RANZCR radiologists used the RANZCR breast density synoptic. Both scales use a 4-point assessment. The images were then grouped as low- and high-density; low including BIRADS 1 and 2 or RANZCR 1 and 2 and high including BI-RADS 3 and 4 or RANZCR 3 and 4. Four-point BI-RADS and RANZCR showed no or negligible correlation (ρ=-0.029 p<0.859). The average inter-observer agreement on the BI-RADS scale had a Kappa of 0.565; [95% CI = 0.519 - 0.610], and ranged between 0.328-0.669 while the inter-observer agreement using the RANZCR scale had a Kappa of 0.360; [95% CI = 0.308 - 0.412] and a range of 0.078-0.499. Our findings show a wider range of inter-observer variability among RANZCR registered radiologists than the ABR examiners.

  18. Nuclear localization of Rad51B is independent of BRCA2

    Miller, K A; Hinz, J M; Yamada, A; Thompson, L H; Albala, J S

    2005-06-28

    Human Rad51 is critical for the maintenance of genome stability through its role in the repair of DNA double-strand breaks. Rad51B (Rad51L1/hRec2) is one of the five known paralogs of human Rad51 found in a multi-protein complex with three other Rad51 paralogs, Rad51C, Rad51D and Xrcc2. Examination of EGFP-Rad51B fusion protein in HeLa S3 cells and immunofluorescence in several human cell lines confirms the nuclear localization of Rad51B. This is the first report to detail putative interactions of a Rad51 paralog protein with BRCA2. Utilization of a BRCA2 mutant cell line, CAPAN-1 suggests that Rad51B localizes to the nucleus independent of BRCA2. Although both Rad51B and BRCA2 are clearly involved in the homologous recombinational repair pathway, Rad51B and BRCA2 do not appear to associate directly. Furthermore, mutations in the KKLK motif of Rad51B, amino acid residues 4-7, mislocalizes Rad51B to the cytoplasm suggesting that this is the nuclear localization signal for the Rad51B protein. Examination of wild-type EGFP-Rad51B fusion protein in mammalian cells deficient in Rad51C showed that Rad51B localizes to the nucleus independent of Rad51C; further suggesting that Rad51B, like Rad51C, contains its own nuclear localization signal.

  19. Type I interferon-dependent activation of NK cells by rAd28 or rAd35, but not rAd5, leads to loss of vector-insert expression.

    Johnson, Matthew J; Björkström, Niklas K; Petrovas, Constantinos; Liang, Frank; Gall, Jason G D; Loré, Karin; Koup, Richard A

    2014-02-01

    Vaccines constructed from rare-serotype recombinant adenovirus vectors (rAd) such as rAd serotype 28 (rAd28) and rAd35 are currently being explored as alternatives to rAd5-based vaccines because they circumvent the problems with pre-existing immunity that complicate the effectiveness of rAd5 vaccines. However, previous work has demonstrated that the immunogenicity of rAd28 and rAd35 is substantially lower than rAd5. Here we show that rAd28 and rAd35 increase apoptosis of antigen presenting cells (APCs), such as monocytes, relative to rAd5 and mock infected controls. APCs undergoing apoptosis showed an increased loss of vector-insert expression. Loss of vector-insert expression correlated with activation of NK cells, which resulted in apoptosis of co-cultured monocytes. Finally, we show that activation of NK cells is dependent on IFNα which is produced by exposure to rAd28 or rAd35, but not to rAd5. Taken together, these data demonstrate that IFNα-induced activation of NK cells leads to increased monocyte apoptosis and subsequent vector-insert loss. This may be a possible mechanism that results in reduced immunogenicity of rAd28 and rAd35-based vectors. PMID:24325826

  20. Correlation of RAD51 and radiosensitization of methotrexate

    Objective: To evaluate the correlation between homologous recombination repair protein RAD51 and methotrexate-enhanced radiosensitivity. Methods: Western blot and RT-PCR assays were used to detect RAD51 expression in HOS osteosarcoma cells exposed to γ-ray irradiation alone and in combination with methotrexate. Colony formation assay was used to test the survival fraction of HOS cells exposed to γ-rays and methotrexate. Results: Methotrexate inhibited both protein and RNA expressions of RAD51, and the combination of radiation and methotrexate enhanced the inhibition of RAD51 expression. Moreover, transfection of cells with RAD51 gene decreased cellular sensitivity to methotrexate and γ-rays. The sensitizer enhancement ratios after irradiation in combination with methotrexate were 1.51 and 0.99, respectively. Methotrexate was a preferred radiosensitizer to HOS cell. Conclusions: RAD51 might be involved in the methotrexate-enhanced radiosensitivity. (authors)

  1. Analysis list: Rad51 [Chip-atlas[Archive

    Full Text Available Rad51 Blood,Gonad + mm9 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Rad51.1.tsv http://dba...rchive.biosciencedbc.jp/kyushu-u/mm9/target/Rad51.5.tsv http://dbarchive.biosciencedbc.jp/k...yushu-u/mm9/target/Rad51.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Rad51.Blood.tsv,http://dba...rchive.biosciencedbc.jp/kyushu-u/mm9/colo/Rad51.Gonad.tsv http://dbarchive.bios...ciencedbc.jp/kyushu-u/mm9/colo/Blood.gml,http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Gonad.gml ...

  2. RadCat 2.0 User Guide.

    Osborn, Douglas.; Weiner, Ruth F.; Mills, George Scott; Hamp, Steve C.; O' Donnell, Brandon, M.; Orcutt, David J.; Heames, Terence J.; Hinojosa, Daniel

    2005-01-01

    This document provides a detailed discussion and a guide for the use of the RadCat 2.0 Graphical User Interface input file generator for the RADTRAN 5.5 code. The differences between RadCat 2.0 and RadCat 1.0 can be attributed to the differences between RADTRAN 5 and RADTRAN 5.5 as well as clarification for some of the input parameters. 3

  3. Sample preparation for 2b-RAD genotyping

    sprotocols

    2015-01-01

    Authors: Shi Wang, Eli Meyer, John McKay & Mikhail Matz ### Abstract High-throughput sequencing of restriction site-associated genomic DNA (RAD) is now a widely used approach for simultaneously discovering and profiling genetic polymorphisms. We describe an alternative approach for RAD genotyping with several useful features, called 2b-RAD for the use of type IIB restriction endonucleases (AlfI, BsaXI). The fragments excised by type IIB enzymes are uniform in length, streamlining ...

  4. Effects of phosphorylation on function of the Rad GTPase.

    Moyers, J S; Zhu, J; Kahn, C R

    1998-08-01

    Rad, Gem and Kir possess unique structural features in comparison with other Ras-like GTPases, including a C-terminal 31-residue extension that lacks typical prenylation motifs. We have recently shown that Rad and Gem bind calmodulin in a Ca2+-dependent manner via this C-terminal extension, involving residues 278-297 in human Rad. This domain also contains several consensus sites for serine phosphorylation, and Rad is complexed with calmodulin-dependent protein kinase II (CaMKII) in C2C12 cells. Here we show that Rad serves as a substrate for phosphorylation by CaMKII, cAMP-dependent protein kinase (PKA), protein kinase C (PKC) and casein kinase II (CKII) with stoichiometries in vitro of 0.2-1.3 mol of phosphate/mol of Rad. By deletion and point mutation analysis we show that phosphorylation by CaMKII and PKA occurs on a single serine residue at position 273, whereas PKC and CKII phosphorylate multiple C-terminal serine residues, including Ser214, Ser257, Ser273, Ser290 and Ser299. Incubation of Rad with PKA decreases GTP binding by 60-70%, but this effect seems to be independent of phosphorylation, as it is observed with the Ser273-->Ala mutant of Rad containing a mutation at the site of PKA phosphorylation. The remainder of the serine kinases have no effect on Rad GTP binding, intrinsic GTP hydrolysis or GTP hydrolysis stimulated by the putative tumour metastasis suppressor nm23. However, phosphorylation of Rad by PKC and CKII abolishes the interaction of Rad with calmodulin. These findings suggest that the binding of Rad to calmodulin, as well as its ability to bind GTP, might be regulated by the activation of several serine kinases. PMID:9677319

  5. Rad52 SUMOylation affects the efficiency of the DNA repair

    Altmannova, Veronika; Eckert-Boulet, Nadine; Arneric, Milica;

    2010-01-01

    Homologous recombination (HR) plays a vital role in DNA metabolic processes including meiosis, DNA repair, DNA replication and rDNA homeostasis. HR defects can lead to pathological outcomes, including genetic diseases and cancer. Recent studies suggest that the post-translational modification by...... recombination and DNA repair....... recombination mediator protein Rad52. Interestingly, Rad52 SUMOylation is enhanced by single-stranded DNA, and we show that SUMOylation of Rad52 also inhibits its DNA binding and annealing activities. The biochemical effects of SUMO modification in vitro are accompanied by a shorter duration of spontaneous Rad...

  6. Effects of Sr2+ doping on the electrical properties of (Bi0.5Na0.50.94Ba0.06TiO3 ceramics

    Amrita Singh

    2015-03-01

    Full Text Available The influence of SrTiO3 addition on the microstructure and various electrical properties of (Bi0.5Na0.50.94Ba0.06TiO3 (BNTBT6 ceramics, fabricated by a conventional high temperature solid state reaction, was investigated. Analysis of X-ray diffraction patterns revealed the formation of phase pure materials with tetragonal unit cell structure, tetragonality parameter c/a in the interval from 0.9940 to 1.0063 and crystallite sizes ranging from 33–76 nm for addition of 0.2 to 1 wt.% of SrTiO3. SEM studies indicated that Sr2+ doping led to decrease in grain size and non-homogeneity of grain distribution for higher SrTiO3 amount (>0.6 wt.%. Complex impedance, modulus, and conductivity studies indicated the presence of grains and grain boundary contribution, non-Debye type of relaxation and NTCR behaviour of the test ceramic samples. Temperature dependent real part of complex permittivity showed peaks at 475 °C and the dielectric loss tangent showed peaks corresponding to 125 °C and 475 °C for almost all compositions. AC activation energies, computed using Arrhenius relation in the temperature range of 325–500 °C for the BNTBT6 ceramic compositions having SrTiO3 concentration from 0.2 to 1.0 wt.%, were seen to have maximal values at the lowest measurement frequency. Amongst the different chosen doped BNTBT6 ceramic compositions, the composition having 0.6 wt.% of SrTiO3 showed the best ferroelectric and piezoelectric response with maximum value of Pr (8.24 µC/cm2, minimum value of Ec (5.73 kV/mm and maximum d33 value (∼46 pC/N.

  7. Piezoelectric, impedance, electric modulus and AC conductivity studies on (Bi0.5Na0.50.95Ba0.05TiO3 ceramic

    Ansu K. Roy

    2013-06-01

    Full Text Available Lead-free piezoelectric perovskite ceramic (Bi0.5Na0.50.95Ba0.05TiO3 (BNT-BT0.05, prepared by conventional high temperature solid state reaction technique at 1160 °C/3h in air atmosphere, is investigated by impedance and modulus spectroscopy in a temperature range 35–400 °C, over a frequency range 100 Hz–1 MHz. The crystal structure, microstructure, and piezoelectric properties as well as the AC conductivity of the sample were studied. Powder X-ray diffraction pattern derived from the resulting data at the room temperature subjected to Rietveld refinements and Williamson-Hall plot analysis confirmed the formation of phase pure compound with monoclinic unit cells having a crystallite-size ~33.8 nm. Observed SEM micrograph showed a uniform distribution of grains inside the sample having an average grain size ~3 mm. Longitudinal piezoelectric charge coefficient of the sample poled under a DC electric field of ~ 2.5 kV/mm at 80 °C in a silicone oil bath was found to be equal to 95 pC/N. The frequency and temperature dependent electrical data analysed in the framework of AC conductivity, complex impedance as well as electric modulus formalisms showed negative temperature coefficient of resistance (NTCR character of the material and the dielectric relaxation in the material to be of non-Debye type. Double power law for the frequency-dependence of AC conductivity and Jump Relaxation Model (JRM were found to explain successfully the mechanism of charge transport in BNT-BT0.05.

  8. Easy Mode Course for Personal Radiation Detectors Thermo Rad Eye

    The presentation describes the use of the Rad Eye Personal Radiation Detector for monitoring and searching.The search alarm of the Rad Eye is based on 6 sigma and its safety alarm is set at 10000 counts per second and 100 micro Sv/h, which is the IAEA default setting

  9. Study on Performance of Empore~(TM) Technetium Rad Disks

    2011-01-01

    EmporeTM Technetium Rad disks produced by 3M Company contain GD-1 sorbent loaded on particles that are embedded in an inert PTFE matrix. In this study, several experiments have been accomplished to evaluate the performance of EmporeTM Technetium Rad disks.

  10. Reactive airways dysfunction syndrome (RADS): fact or fantasy?

    Bardana, E J

    1999-01-01

    Most evidence suggests that RADS is a distinct syndrome and not simply an exacerbation of pre-existing hyperresponsiveness. There is no doubt that much remains to be explained regarding pathogenesis. On the other hand, I urge caution about the claims of "low-level RADS". Here the data are much more anecdotal and leave much to be desired. PMID:10735647

  11. Anomalous weak ferromagnetism in electron-doped Nd{sub 1-x}Sr{sub x}MnO{sub 3} (0.50 {<=} x {<=} 0.62) thin films

    Kumar, Pawan; Dwivedi, Rakesh Kumar [Jaypee Institute of Information Technology, Uttar Pradesh (India); Prasad, Ravikant; Srivastava, Avanish Kumar; Singh, Hari Krishna [National Physical Laboratory, New Delhi (India); Singh, Mangala Prasad [Brock University, St. Catharines (Canada)

    2011-10-15

    In the present work, we demonstrate that an anomalous weak ferromagnetism occurs in the composition range 0.50 {<=} x {<=} 0.62 in nanostructured thin films of Nd{sub 1-x}Sr{sub x}MnO{sub 3} (NSMO). Nanocrystalline thin films of overdoped manganite Nd{sub 1-x}Sr{sub x}MnO{sub 3} (x {approx} 0.50, 0.55, 0.60, and 0.62) are grown on single-crystal LaAlO{sub 3} (001) substrates by using a nebulized chemical spray pyrolysis technique. These single phase films possess an average crystallite size {approx}15 nm, and the width of the grain boundaries is {approx}1 - 2 nm. In the composition range 0.50 {<=} x {<=} 0.62, the ground state of NSMO is an A-type antiferromagnetic (AFM) metallic state. However, in the present films, a broad paramagnetic (PM)-to-ferromagnetic (FM) transition is observed in all the compositions, at T{sub C} {approx} 226 K for x = 0.50 and at 235 K for rest of the samples. All the films show a well-defined M-H hysteresis loop at 5 K. The coercivity (H{sub C}) of these films is much larger than those having compositions in the range 0.35 < x < 0.45. For x = 0.50 (0.62), the films H{sub C} = -1210 (-1484) Oe and +1162 (+1476) Oe. The asymmetry in the coercivity suggests the presence of a weak exchange bias effect in these films. The FM ground state in these films is observed to have a smaller magnetic moment per Mn atom than the expected full moment from the rigid model; we term this as a weak ferromagnetic (WFM) state arising due to the destabilization of the AFM ordering. We propose a possible scenario based on the combined effect of spin reorganization and enhanced orbital disordering in nanosized manganites to explain the observed anomalous weak ferromagnetism in the A-type AFM spin ordered region.

  12. The Saccharomyces cerevisiae RAD9, RAD17, RAD24 and MEC3 genes are required for tolerating irreparable, ultraviolet-induced DNA damage

    In wild-type Saccharomyces cerevisiae, a checkpoint slows the rate of progression of an ongoing S phase in response to exposure to a DNA-alkylating agent. Mutations that eliminate S phase regulation also confer sensitivity to alkylating agents, leading us to suggest that, by regulating the S phase rate, cells are either better able to repair or better able to replicate damaged DNA. In this study, we determine the effects of mutations that impair S phase regulation on the ability of excision repair-defective cells to replicate irreparably UV-damaged DNA. We assay survival after UV irradiation, as well as the genetic consequences of replicating a damaged template, namely mutation and sister chromatid exchange induction. We find that RAD9, RAD17, RAD24, and MEC3 are required for UV-induced (although not spontaneous) mutagenesis, and that RAD9 and RAD17 (but not REV3, RAD24, and MEC3) are required for maximal induction of replication-dependent sister chromatid exchange. Therefore, checkpoint genes not only control cell cycle progression in response to damage, but also play a role in accommodating DNA damage during replication. (author)

  13. Synthesis and characterization particles of Ba0,50Sr0,50Co0,80Fe0,20O3 obtained by the citrate-EDTA technique

    The Ba(1-x)Sr(x)Co(1-y)Fe(y)O(3) (BSCF) has been studied as a cathode material for Intermediate Temperature Solid Oxide Fuel Cell, due to its better ion and electron conduction. This work aims to study the synthesis of the compound obtained from the citrate-EDTA technique. Thermogravimetric analysis indicated the formation of the compound above 800 deg C. The materials calcined at temperatures of 700, 800 and 900 deg C for 5 h showed cubic pseudo-perovskite structure, according to the literature. By analysis of X-ray fluorescence were obtained powders with nominal chemical composition in the temperature range studied. The micrographs obtained by SEM and particle size distribution analysis showed the formation of particle with diameters below 1 micron. (author)

  14. Determination of radon concentration in water using RAD7 with RAD H{sub 2}O accessories

    Malik, M. F. I. [Science and Engineering Research Centre (SERC), Universiti Sains Malaysia, Seri Ampangan Nibong Tebal 14300 Penang (Malaysia); Rabaiee, N. A.; Jaafar, M. S. [School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia)

    2015-04-24

    In the last decade, the radon issue has become one of the major problems of radiation protection. Radon exposure occurs when using water for showering, washing dishes, cooking and drinking water. RAD7 and Rad H20 accessories were used in order to measure radon concentration in water sample. In this study, four types of water were concerns which are reverse osmosis (drinking water), mineral water, tap water and well water. Reverse osmosis (drinking water) and mineral water were bought from the nearest supermarket while tap water and well water were taken from selected areas of Pulau Pinang and Kedah. Total 20 samples were taken with 5 samples for each type of water. The measured radon concentration ranged from 2.9±2.9 to 79.5±17 pCi/L, 2.9±2.9 to 67.8±16 pCi/L, 15.97±7 to 144.25±24 pCi/L and 374.89±37 to 6409.03±130 pCi/L in reverse osmosis (drinking water), mineral water, tap water and well water. Well water has the highest radon compared to others. It was due to their geological element such as granite. Results for all types of water are presented and compared with maximum contamination limit (MCL) recommended by United State Environmental Protection Agency (USEPA) which is 300pCi/L. Reverse osmosis water, mineral water and tap water were fall below MCL. However, well water was exceeded maximum level that was recommended. Thus, these findings were suggested that an action should be taken to reduce radon concentration level in well water as well as reduce a health risk towards the public.

  15. Interrogation of the protein-protein interactions between human BRCA2 BRC repeats and RAD51 reveals atomistic determinants of affinity.

    Cole, Daniel J; Rajendra, Eeson; Roberts-Thomson, Meredith; Hardwick, Bryn; McKenzie, Grahame J; Payne, Mike C; Venkitaraman, Ashok R; Skylaris, Chris-Kriton

    2011-07-01

    The breast cancer suppressor BRCA2 controls the recombinase RAD51 in the reactions that mediate homologous DNA recombination, an essential cellular process required for the error-free repair of DNA double-stranded breaks. The primary mode of interaction between BRCA2 and RAD51 is through the BRC repeats, which are ∼35 residue peptide motifs that interact directly with RAD51 in vitro. Human BRCA2, like its mammalian orthologues, contains 8 BRC repeats whose sequence and spacing are evolutionarily conserved. Despite their sequence conservation, there is evidence that the different human BRC repeats have distinct capacities to bind RAD51. A previously published crystal structure reports the structural basis of the interaction between human BRC4 and the catalytic core domain of RAD51. However, no structural information is available regarding the binding of the remaining seven BRC repeats to RAD51, nor is it known why the BRC repeats show marked variation in binding affinity to RAD51 despite only subtle sequence variation. To address these issues, we have performed fluorescence polarisation assays to indirectly measure relative binding affinity, and applied computational simulations to interrogate the behaviour of the eight human BRC-RAD51 complexes, as well as a suite of BRC cancer-associated mutations. Our computational approaches encompass a range of techniques designed to link sequence variation with binding free energy. They include MM-PBSA and thermodynamic integration, which are based on classical force fields, and a recently developed approach to computing binding free energies from large-scale quantum mechanical first principles calculations with the linear-scaling density functional code onetep. Our findings not only reveal how sequence variation in the BRC repeats directly affects affinity with RAD51 and provide significant new insights into the control of RAD51 by human BRCA2, but also exemplify a palette of computational and experimental tools for the

  16. Interrogation of the protein-protein interactions between human BRCA2 BRC repeats and RAD51 reveals atomistic determinants of affinity.

    Daniel J Cole

    2011-07-01

    Full Text Available The breast cancer suppressor BRCA2 controls the recombinase RAD51 in the reactions that mediate homologous DNA recombination, an essential cellular process required for the error-free repair of DNA double-stranded breaks. The primary mode of interaction between BRCA2 and RAD51 is through the BRC repeats, which are ∼35 residue peptide motifs that interact directly with RAD51 in vitro. Human BRCA2, like its mammalian orthologues, contains 8 BRC repeats whose sequence and spacing are evolutionarily conserved. Despite their sequence conservation, there is evidence that the different human BRC repeats have distinct capacities to bind RAD51. A previously published crystal structure reports the structural basis of the interaction between human BRC4 and the catalytic core domain of RAD51. However, no structural information is available regarding the binding of the remaining seven BRC repeats to RAD51, nor is it known why the BRC repeats show marked variation in binding affinity to RAD51 despite only subtle sequence variation. To address these issues, we have performed fluorescence polarisation assays to indirectly measure relative binding affinity, and applied computational simulations to interrogate the behaviour of the eight human BRC-RAD51 complexes, as well as a suite of BRC cancer-associated mutations. Our computational approaches encompass a range of techniques designed to link sequence variation with binding free energy. They include MM-PBSA and thermodynamic integration, which are based on classical force fields, and a recently developed approach to computing binding free energies from large-scale quantum mechanical first principles calculations with the linear-scaling density functional code onetep. Our findings not only reveal how sequence variation in the BRC repeats directly affects affinity with RAD51 and provide significant new insights into the control of RAD51 by human BRCA2, but also exemplify a palette of computational and

  17. Astaxanthin down-regulates Rad51 expression via inactivation of AKT kinase to enhance mitomycin C-induced cytotoxicity in human non-small cell lung cancer cells.

    Ko, Jen-Chung; Chen, Jyh-Cheng; Wang, Tai-Jing; Zheng, Hao-Yu; Chen, Wen-Ching; Chang, Po-Yuan; Lin, Yun-Wei

    2016-04-01

    Astaxanthin has been demonstrated to exhibit a wide range of beneficial effects, including anti-inflammatory and anti-cancer properties. However, the molecular mechanism of astaxanthin-induced cytotoxicity in non-small cell lung cancer (NSCLC) cells has not been identified. Rad51 plays a central role in homologous recombination, and studies show that chemo-resistant carcinomas exhibit high levels of Rad51 expression. In this study, astaxanthin treatment inhibited cell viability and proliferation of two NSCLC cells, A549 and H1703. Astaxanthin treatment (2.5-20μM) decreased Rad51 expression and phospho-AKT(Ser473) protein level in a time and dose-dependent manner. Furthermore, expression of constitutively active AKT (AKT-CA) vector rescued the decreased Rad51 mRNA and protein levels in astaxanthin-treated NSCLC cells. Combined treatment with phosphatidylinositol 3-kinase (PI3K) inhibitors (LY294002 or wortmannin) further decreased the Rad51 expression in astaxanthin-exposed A549 and H1703 cells. Knockdown of Rad51 expression by transfection with si-Rad51 RNA or cotreatment with LY294002 further enhanced the cytotoxicity and cell growth inhibition of astaxanthin. Additionally, mitomycin C (MMC) as an anti-tumor antibiotic is widely used in clinical NSCLC chemotherapy. Combination of MMC and astaxanthin synergistically resulted in cytotoxicity and cell growth inhibition in NSCLC cells, accompanied with reduced phospho-AKT(Ser473) level and Rad51 expression. Overexpression of AKT-CA or Flag-tagged Rad51 reversed the astaxanthin and MMC-induced synergistic cytotoxicity. In contrast, pretreatment with LY294002 further decreased the cell viability in astaxanthin and MMC co-treated cells. In conclusion, astaxanthin enhances MMC-induced cytotoxicity by decreasing Rad51 expression and AKT activation. These findings may provide rationale to combine astaxanthin with MMC for the treatment of NSCLC. PMID:26921637

  18. The SRS2 suppressor of rad6 mutations of Saccharomyces cerevisiae acts by channeling DNA lesions into the RAD52 DNA repair pathway

    rad6 mutants of Saccharomyces cerevisiae are defective in the repair of damaged DNA, DNA damage induced mutagenesis, and sporulation. In order to identify genes that can substitute for RAD6 function, the authors have isolated genomic suppressors of the UV sensitivity of rad6 deletion (rad6Δ) mutations and show that they also suppress the γ-ray sensitivity but not the UV mutagenesis or sporulation defects of rad6. The suppressors show semidominance for suppression of UV sensitivity and dominance for suppression of γ-ray sensitivity. The six suppressor mutations they isolated are all alleles of the same locus and are also allelic to a previously described suppressor of the rad6-1 nonsense mutation, SRS2. They show that suppression of rad6Δ is dependent on the RAD52 recombinational repair pathway since suppression is not observed in the rad6Δ SRS2 strain containing an additional mutation in either the RAD51, RAD52, RAD54, RAD55 or RAD57 genes. Possible mechanisms by which SRS2 may channel unrepaired DNA lesions into the RAD52 DNA repair pathway are discussed

  19. Aktsiisiseaduse muudatused 2006. aastal : aktsiisimäärad / Urmas Koidu

    Koidu, Urmas

    2006-01-01

    2006. aastal jõustunud alkoholi-, tubaka- ja kütuseaktsiisi seaduse muudatustest. Lisatud tabelid: alkoholi aktsiisimäärad Eestis 2006-2008 ja ELi aktsiisi alammäärad (krooni); tubakatoodete aktsiisimäärad Eestis 2006-2008 ja ELi aktsiisi alammäärad; mootorikütuse aktsiisimäärad Eestis ja ELi alammäärad; kütteainete ja elektrienergia aktsiisimäärad Eestis ja ELi alammäärad

  20. Synthesis and characterization particles of Ba{sub 0,50}Sr{sub 0,50}Co{sub 0,80}Fe{sub 0,20}O{sub 3} obtained by the citrate-EDTA technique; Sintese e caracterizacao de particulados de Ba{sub 0,50}Sr{sub 0,50}Co{sub 0,80}Fe{sub 0,20}O{sub 3} obtidos pela tecnica dos citratos-EDTA

    Bonturim, E.; Vargas, R.A.; Andreoli, M.; Seo, E.S.M., E-mail: ebonturim@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (CCTM/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencia e Tecnologia de Materiais

    2010-07-01

    The Ba{sub (1-x)}Sr{sub (x)}Co{sub (1-y)}Fe{sub (y)}O{sub (3)} (BSCF) has been studied as a cathode material for Intermediate Temperature Solid Oxide Fuel Cell, due to its better ion and electron conduction. This work aims to study the synthesis of the compound obtained from the citrate-EDTA technique. Thermogravimetric analysis indicated the formation of the compound above 800 deg C. The materials calcined at temperatures of 700, 800 and 900 deg C for 5 h showed cubic pseudo-perovskite structure, according to the literature. By analysis of X-ray fluorescence were obtained powders with nominal chemical composition in the temperature range studied. The micrographs obtained by SEM and particle size distribution analysis showed the formation of particle with diameters below 1 micron. (author)

  1. Molecular characterization of RadLV (radiation leukemia virus)

    Following a course of a fractionated whole-body x-irradiation, a high percentage of C57BL/Ka mice develop thymic lymphomas. Radiation leukemia virus (RadLV) can be consistently isolated from these tumors. RadLV can induce identical lymphomas in unirradiated C57BL/Ka mice, and its role as the etiologic agent of these malignancies has been clearly documented. In order to characterize the viral genome at the molecular level, the unintegrated DNA intermediates of several RadLV isolates were prepared. Several different protocols were developed to optimize the yield and quality of restriction endonucleases, and cloned into a bacteriophage vector using recombinant DNA technology. RadLV is a general term used to describe a number of lymphomagenic viruses isolated from (1) primary radiation-induced lymphomas, (2) virus-induced lymphomas, and (3) established cell lines. The RadLV viruses replicate preferentially in the thymus and cause thymic lymphomas. Non-thymotropic, non-oncogenic, fibrotropic viruses can also be isolated from C57BL/Ka mice. Thus, a spectrum of biological activities can be seen among the C57BL/Ka mouse retroviruses. This dissertation reports the molecular cloning of three of the RadLV viruses. They are: (1) RadLV/VL3 and (2) RadLV/RL10, both lymphomagenic viruses, and (3) RadLV/RL15, a non-oncogenic isolate. The generation of restriction maps from both the cloned DNAs and the unintegrated viral DNA intermediates is described. These maps are compared with those of other C57BL/Ka murine retroviruses, and with published maps of other murine leukemia viruses

  2. RAD/COMM ''Cricket'' Test Report

    Chiaro, P J

    2002-01-01

    A series of tests were performed at Oak Ridge National Laboratory (ORNL) to evaluate and characterize the radiological response of a ''Cricket'' radiation detection system. The ''Cricket'' is manufactured by RAD/COMM Systems Corp., which is located in Ontario, Canada. The system is designed to detect radioactive material that may be contained in scrap metal. The Cricket's detection unit is mounted to the base of a grappler and monitors material, while the grappler's tines hold the material. It can also be used to scan material in an attempt to isolate radioactive material if an alarm occurs. Testing was performed at the Environmental Effects Laboratory located at ORNL and operated by the Engineering Science and Technology Division. Tests performed included the following: (1) Background stability, (2) Energy response using sup 2 sup 4 sup 1 Am, sup 1 sup 3 sup 7 Cs, and sup 6 sup 0 Co, (3) Surface uniformity, (4) Angular dependence, (5) Alarm actuation, (6) Alarm threshold vs. background, (7) Shielding, (8) Re...

  3. The Martian surface radiation environment – a comparison of models and MSL/RAD measurements

    Matthiä Daniel

    2016-01-01

    Full Text Available Context: The Radiation Assessment Detector (RAD on the Mars Science Laboratory (MSL has been measuring the radiation environment on the surface of Mars since August 6th 2012. MSL-RAD is the first instrument to provide detailed information about charged and neutral particle spectra and dose rates on the Martian surface, and one of the primary objectives of the RAD investigation is to help improve and validate current radiation transport models. Aims: Applying different numerical transport models with boundary conditions derived from the MSL-RAD environment the goal of this work was to both provide predictions for the particle spectra and the radiation exposure on the Martian surface complementing the RAD sensitive range and, at the same time, validate the results with the experimental data, where applicable. Such validated models can be used to predict dose rates for future manned missions as well as for performing shield optimization studies. Methods: Several particle transport models (GEANT4, PHITS, HZETRN/OLTARIS were used to predict the particle flux and the corresponding radiation environment caused by galactic cosmic radiation on Mars. From the calculated particle spectra the dose rates on the surface are estimated. Results: Calculations of particle spectra and dose rates induced by galactic cosmic radiation on the Martian surface are presented. Although good agreement is found in many cases for the different transport codes, GEANT4, PHITS, and HZETRN/OLTARIS, some models still show large, sometimes order of magnitude discrepancies in certain particle spectra. We have found that RAD data is helping to make better choices of input parameters and physical models. Elements of these validated models can be applied to more detailed studies on how the radiation environment is influenced by solar modulation, Martian atmosphere and soil, and changes due to the Martian seasonal pressure cycle. By extending the range of the calculated particle

  4. The Martian surface radiation environment - a comparison of models and MSL/RAD measurements

    Matthiä, Daniel; Ehresmann, Bent; Lohf, Henning; Köhler, Jan; Zeitlin, Cary; Appel, Jan; Sato, Tatsuhiko; Slaba, Tony; Martin, Cesar; Berger, Thomas; Boehm, Eckart; Boettcher, Stephan; Brinza, David E.; Burmeister, Soenke; Guo, Jingnan; Hassler, Donald M.; Posner, Arik; Rafkin, Scot C. R.; Reitz, Günther; Wilson, John W.; Wimmer-Schweingruber, Robert F.

    2016-03-01

    Context: The Radiation Assessment Detector (RAD) on the Mars Science Laboratory (MSL) has been measuring the radiation environment on the surface of Mars since August 6th 2012. MSL-RAD is the first instrument to provide detailed information about charged and neutral particle spectra and dose rates on the Martian surface, and one of the primary objectives of the RAD investigation is to help improve and validate current radiation transport models. Aims: Applying different numerical transport models with boundary conditions derived from the MSL-RAD environment the goal of this work was to both provide predictions for the particle spectra and the radiation exposure on the Martian surface complementing the RAD sensitive range and, at the same time, validate the results with the experimental data, where applicable. Such validated models can be used to predict dose rates for future manned missions as well as for performing shield optimization studies. Methods: Several particle transport models (GEANT4, PHITS, HZETRN/OLTARIS) were used to predict the particle flux and the corresponding radiation environment caused by galactic cosmic radiation on Mars. From the calculated particle spectra the dose rates on the surface are estimated. Results: Calculations of particle spectra and dose rates induced by galactic cosmic radiation on the Martian surface are presented. Although good agreement is found in many cases for the different transport codes, GEANT4, PHITS, and HZETRN/OLTARIS, some models still show large, sometimes order of magnitude discrepancies in certain particle spectra. We have found that RAD data is helping to make better choices of input parameters and physical models. Elements of these validated models can be applied to more detailed studies on how the radiation environment is influenced by solar modulation, Martian atmosphere and soil, and changes due to the Martian seasonal pressure cycle. By extending the range of the calculated particle spectra with respect to

  5. RadNet Real-Time Monitoring Spectrometry Data Inventory

    U.S. Environmental Protection Agency — The RadNet Real-Time Monitoring Spectrometry Data Inventory contains measured data used to identify and measure specific radioactive materials in the atmosphere at...

  6. RadNet (Environmental Radiation Ambient Monitoring System)

    U.S. Environmental Protection Agency — RadNet, formerly Environmental Radiation Ambient Monitoring System (ERAMS), is a national network of monitoring stations that regularly collect air, precipitation,...

  7. RadNet-Air Near Real Time Data

    U.S. Environmental Protection Agency — RadNet-Air is a national network of air monitoring stations that regularly collect air samples for near real time analysis of radioactivity. The data is transmitted...

  8. Rad-hard embedded computers for nuclear robotics

    For requirements of nuclear industries, it is necessary to use robots with embedded rad hard electronics and high level safety. The computer developed for french research program SYROCO is presented in this paper. (authors). 8 refs., 5 figs

  9. RADTRAN 6/RadCat 6 user guide.

    Weiner, Ruth F.; Hinojosa, Daniel; Heames, Terence John; Farnum, Cathy Ottinger; Kalinina, Elena Arkadievna

    2013-09-01

    This document provides a detailed discussion and a guide for the use of the RadCat 6.0 Graphical User Interface input file generator for the RADTRAN code, Version 6. RadCat 6.0 integrates the newest analysis capabilities of RADTRAN 6.0, including an economic model, updated loss-of-lead shielding model, a new ingestion dose model, and unit conversion. As of this writing, the RADTRAN version in use is RADTRAN 6.02.

  10. Methods for measuring sub-pm rad vertical emittance at the Swiss Light Source

    Breunlin, J.; Andersson, Å.; Milas, N.; Saá Hernández, Á.; Schlott, V.

    2015-12-01

    We report on methods capable of measuring a rms vertical electron beam size of 3 μm with a rms error of less than 10% at a diagnostic beamline at the Swiss Light Source (SLS). This corresponds to a vertical emittance of 0.6 pm rad with a 20% rms error. We showed this capability by presenting the theoretical basis for, and the data from, a series of measurements on a stable beam at 1.6 pm rad vertical emittance at the SLS. The methods presented utilized either π- or σ-polarized synchrotron radiation (SR) in the visible to ultra violet (vis-UV) spectral range. In addition to the established π-polarization method, we introduced a diffraction method with a potentially high resolution capability. Also an intensity imbalanced diffraction scheme was introduced, but was found to be prone to SR induced carbon contamination on optical elements.

  11. Protein-DNA interactions in high speed AFM: single molecule diffusion analysis of human RAD54.

    Sanchez, Humberto; Suzuki, Yuki; Yokokawa, Masatoshi; Takeyasu, Kunio; Wyman, Claire

    2011-11-01

    High-speed AFM (atomic force microscopy also called scanning force microscopy) provides nanometre spatial resolution and sub-second temporal resolution images of individual molecules. We exploit these features to study diffusion and motor activity of the RAD54 DNA repair factor. Human RAD54 functions at critical steps in recombinational-DNA repair. It is a member of the Swi2/Snf2 family of chromatin remodelers that translocate on DNA using ATP hydrolysis. A detailed single molecular description of DNA-protein interactions shows intermediate states and distribution of variable states, usually hidden by ensemble averaging. We measured the motion of individual proteins using single-particle tracking and observed that random walks were affected by imaging-buffer composition. Non-Brownian diffusion events were characterized in the presence and in the absence of nucleotide cofactors. Double-stranded DNA immobilized on the surface functioned as a trap reducing Brownian motion. Distinct short range slides and hops on DNA were visualized by high-speed AFM. These short-range interactions were usually inaccessible by other methods based on optical resolution. RAD54 monomers displayed a diffusive behavior unrelated to the motor activity. PMID:21986699

  12. Compensatory role for Rad52 during recombinational repair in Ustilago maydis

    Kojic, Milorad; Mao, Ninghui; Zhou, Qingwen;

    2008-01-01

    spontaneous mutator activity, allelic recombination or meiosis. GFP-Rad51 foci were formed in rad52 cells following DNA damage, but were initially less intense than normal suggesting a possible role for Rad52 in formation of the Rad51 nucleoprotein filament. A search for interacting genes that confer a...

  13. Avaliação das propriedades do Ba0,50Sr0,50Co0,80Fe0,20O3-d para células a combustível de óxido sólido de temperatura intermediária obtido pelo método citratos-EDTA Evaluation of the properties of Ba0,50Sr0.50Co0.80Fe0.20O3-d obtained by the citrate-EDTA method for intermediate temperature solid oxide fuel cell

    E. Bonturim

    2013-03-01

    Full Text Available Ba0,50Sr0,50Co0,80Fe0,20O3-d (BSCF apresenta propriedades físicas, químicas e microestruturais adequadas para compor o cátodo de uma célula a combustível de óxido sólido de temperatura intermediária (ITSOFC. Este trabalho tem por objetivo a síntese e a caracterização do BSCF obtido pelo método dos citrados-EDTA. Os resultados obtidos por difração de raios X (DRX indicaram fases secundárias para o material calcinado a 700 e 800 ºC e fase única com estrutura cristalina do tipo perovskita para 900 ºC. As micrografias obtidas por microscopia eletrônica de varredura dos particulados evidenciou a formação de aglomerados de tamanho Ba0.50Sr0.50Co0.80Fe0.20O3-d (BSCF presents physical, chemical and microstructural properties suitable to form the cathode of Intermediate Temperature Solid Oxide Fuel Cell (ITSOFC. This work aims the synthesis and characterization of BSCF, obtained by the citrate-EDTA method. The X-ray diffraction results indicate secondary phases for the material calcined at 700 and 800 °C and single phase with perovskite crystalline structure at 900 °C. The SEM-FEG particles micrographs show the formation of < 20 µm clusters. The dilatometric analysis of pellets indicates the sintering temperature at ~ 1050 °C. XRD results of the sintered samples show perovskite single phase. The SEM micrographs confirmed the formation of higher porosity in the samples sintered at 1000 °C/1 h using powders calcined at 900 °C.

  14. Reactivities of radicals of adenine and guanine towards reactive oxygen species and reactive nitrogen oxide species: OH rad and NO 2rad

    Agnihotri, Neha; Mishra, P. C.

    2011-02-01

    Reactions of radicals of the DNA bases with reactive oxygen species and reactive nitrogen oxide species produce mutagenic products. We have studied reactivities of all the carbon sites of radicals of adenine A(-H) rad and guanine G(-H) rad obtained by removal of H-atoms from their nitrogen sites towards OH rad and NO 2rad . We studied stabilities of A(-H) rad and G(-H) rad and binding energies of their adducts with each of OH rad and NO 2rad using density functional theoretic and MP2 calculations employing the AUG-cc-pVDZ basis set. Solvation in aqueous media was treated using the polarization continuum model. The results obtained explain experimental observations.

  15. Intraobserver interpretation of breast ultrasonography following the BI-RADS classification

    Purpose: To use the BI-RADS ultrasound classification in an intraobserver retrospective study of the interpretation of breast images. Materials and Methods: The study used 40 breast ultrasound images recorded in orthogonal planes, obtained from patients with an indication for surgery. Eight professionals experienced in breast imaging analysis retrospectively reviewed these lesions, in three rounds of image interpretation (with a 3-6 months interval between rounds). Observers had no access to information from medical records or histopathological results, and, without their knowledge, in each new round were assigned the same images previously interpreted by them. Fleiss-modified Kappa measures were the study main concordance index. Besides the BI-RADS, a scale grouping its categories 2-3 and 4-5 was also used. The statistical analysis concerned the intraobserver agreement. Results: Kappa values ranged from 0.37 to 0.75 (original categories) and from 0.73 to 0.87 (grouped categories). Overall, out of the 8 observers, 7 presented moderate to substantial concordance (Kappa values 0.51 to 0.74). Conclusion: The BI-RADS is a reporting tool that provides a standardized terminology for US exams. In this study, moderate to substantial concordance in Kappa values was found, in agreement with other studies of the literature.

  16. Yeast rad7-rad16 complex, specific for the nucleotide excision repair of the nontranscribed DNA strand, is an ATP-dependent DNA damage sensor

    In eukaryotes, nucleotide excision repair of ultraviolet light-damaged DNA is a highly intricate process that requires a large number of evolutionary conserved protein factors. Genetic studies in the yeast Saccharomyces cerevisiae have indicated a specific role of the RAD7 and RAD16 genes in the repair of transcriptionally inactive DNA. Here we show that the RAD7- and RAD16-encoded products exist as a complex of 1:1 stoichiometry, exhibiting an apparent dissociation constant (Kd) of <4 x 10(-10) M. The Rad7-Rad16 complex has been purified to near homogeneity in this study and is shown to bind, in an ATP-dependent manner and with high specificity, to DNA damaged by ultraviolet light. Importantly, inclusion of the Rad7-Rad16 complex in the in vitro nucleotide excision repair system that consists entirely of purified components results in a marked stimulation of damage specific incision. Thus, Rad7-Rad16 complex is the ATP-dependent DNA damage sensor that specifically functions with the ensemble of nucleotide excision repair factor (NEF) 1, NEF2, NEF3, and replication protein A in the repair of transcriptionally inactive DNA. We name this novel complex of Rad7 and Rad16 proteins NEF4. (author)

  17. Magnetic properties of U(Ni1-xCux)2Si2 solid solutions in the vicinity of x = 0.50 studied by neutron diffraction and AC-susceptibility

    The magnetic properties of two U(Ni1-xCux)2Si2 solid in the vicinity of x = 0.50 (denoted I and II) have been studied by neutron diffraction and ac-susceptibility. Both materials have ThCr2Si2-type crystallographic structure. AC-susceptibility shows antiferromagnetic transitions at TN150±5 K in UNiCuSi2(I) and 155±5 K in UNiCuSi2(II), followed by several transitions with ferrimagnetic (F) character at lower temperatures. Apart from the transitions to AF-I structure at TN=150K and 152K none of the F transitions is observed by neutron diffraction. Short-range magnetic order, involving several consecutive ferromagnetic planes or ferrimagnetic groups of planes in the AF-I phase, detected by ac-susceptibility and not by neutron diffraction in both materials and therefore significant to x ∼ 0.50, is proposed to explain the unusual susceptibility. (Author)

  18. The C-terminal region of Rad52 is essential for Rad52 nuclear and nucleolar localization, and accumulation at DNA damage sites immediately after irradiation

    Highlights: •Rad52 might play a key role in the repair of DSB immediately after irradiation. •EYFP-Rad52 accumulates rapidly at DSB sites and colocalizes with Ku80. •Accumulation of Rad52 at DSB sites is independent of the core NHEJ factors. •Localization and recruitment of Rad52 to DSB sites are dependent on the Rad52 CTR. •Basic amino acids in Rad52 CTR are highly conserved among vertebrate species. -- Abstract: Rad52 plays essential roles in homologous recombination (HR) and repair of DNA double-strand breaks (DSBs) in Saccharomyces cerevisiae. However, in vertebrates, knockouts of the Rad52 gene show no hypersensitivity to agents that induce DSBs. Rad52 localizes in the nucleus and forms foci at a late stage following irradiation. Ku70 and Ku80, which play an essential role in nonhomologous DNA-end-joining (NHEJ), are essential for the accumulation of other core NHEJ factors, e.g., XRCC4, and a HR-related factor, e.g., BRCA1. Here, we show that the subcellular localization of EYFP-Rad52(1–418) changes dynamically during the cell cycle. In addition, EYFP-Rad52(1–418) accumulates rapidly at microirradiated sites and colocalizes with the DSB sensor protein Ku80. Moreover, the accumulation of EYFP-Rad52(1–418) at DSB sites is independent of the core NHEJ factors, i.e., Ku80 and XRCC4. Furthermore, we observed that EYFP-Rad52(1–418) localizes in nucleoli in CHO-K1 cells and XRCC4-deficient cells, but not in Ku80-deficient cells. We also found that Rad52 nuclear localization, nucleolar localization, and accumulation at DSB sites are dependent on eight amino acids (411–418) at the end of the C-terminal region of Rad52 (Rad52 CTR). Furthermore, basic amino acids on Rad52 CTR are highly conserved among mammalian, avian, and fish homologues, suggesting that Rad52 CTR is important for the regulation and function of Rad52 in vertebrates. These findings also suggest that the mechanism underlying the regulation of subcellular localization of Rad52 is

  19. The C-terminal region of Rad52 is essential for Rad52 nuclear and nucleolar localization, and accumulation at DNA damage sites immediately after irradiation

    Koike, Manabu, E-mail: m_koike@nirs.go.jp [DNA Repair Gene Res., National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Yutoku, Yasutomo [DNA Repair Gene Res., National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Graduate School of Science, Chiba University, Yayoicho, Inage-ku, Chiba 263-8522 (Japan); Koike, Aki [DNA Repair Gene Res., National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan)

    2013-05-31

    Highlights: •Rad52 might play a key role in the repair of DSB immediately after irradiation. •EYFP-Rad52 accumulates rapidly at DSB sites and colocalizes with Ku80. •Accumulation of Rad52 at DSB sites is independent of the core NHEJ factors. •Localization and recruitment of Rad52 to DSB sites are dependent on the Rad52 CTR. •Basic amino acids in Rad52 CTR are highly conserved among vertebrate species. -- Abstract: Rad52 plays essential roles in homologous recombination (HR) and repair of DNA double-strand breaks (DSBs) in Saccharomyces cerevisiae. However, in vertebrates, knockouts of the Rad52 gene show no hypersensitivity to agents that induce DSBs. Rad52 localizes in the nucleus and forms foci at a late stage following irradiation. Ku70 and Ku80, which play an essential role in nonhomologous DNA-end-joining (NHEJ), are essential for the accumulation of other core NHEJ factors, e.g., XRCC4, and a HR-related factor, e.g., BRCA1. Here, we show that the subcellular localization of EYFP-Rad52(1–418) changes dynamically during the cell cycle. In addition, EYFP-Rad52(1–418) accumulates rapidly at microirradiated sites and colocalizes with the DSB sensor protein Ku80. Moreover, the accumulation of EYFP-Rad52(1–418) at DSB sites is independent of the core NHEJ factors, i.e., Ku80 and XRCC4. Furthermore, we observed that EYFP-Rad52(1–418) localizes in nucleoli in CHO-K1 cells and XRCC4-deficient cells, but not in Ku80-deficient cells. We also found that Rad52 nuclear localization, nucleolar localization, and accumulation at DSB sites are dependent on eight amino acids (411–418) at the end of the C-terminal region of Rad52 (Rad52 CTR). Furthermore, basic amino acids on Rad52 CTR are highly conserved among mammalian, avian, and fish homologues, suggesting that Rad52 CTR is important for the regulation and function of Rad52 in vertebrates. These findings also suggest that the mechanism underlying the regulation of subcellular localization of Rad52 is

  20. A novel interation of nucleolin with Rad51

    Nucleolin associates with various DNA repair, recombination, and replication proteins, and possesses DNA helicase, strand annealing, and strand pairing activities. Examination of nuclear protein extracts from human somatic cells revealed that nucleolin and Rad51 co-immunoprecipitate. Furthermore, purified recombinant Rad51 associates with in vitro transcribed and translated nucleolin. Electroporation-mediated introduction of anti-nucleolin antibody resulted in a 10- to 20-fold reduction in intra-plasmid homologous recombination activity in human fibrosarcoma cells. Additionally, introduction of anti-nucleolin antibody sensitized cells to death induced by the topoisomerase II inhibitor, amsacrine. Introduction of anti-Rad51 antibody also reduced intra-plasmid homologous recombination activity and induced hypersensitivity to amsacrine-induced cell death. Co-introduction of anti-nucleolin and anti-Rad51 antibodies did not produce additive effects on homologous recombination or on cellular sensitivity to amsacrine. The association of the two proteins raises the intriguing possibility that nucleolin binding to Rad51 may function to regulate homologous recombinational repair of chromosomal DNA

  1. RAD18 mediates resistance to ionizing radiation in human glioma cells

    Xie, Chen; Wang, Hongwei; Cheng, Hongbin; Li, Jianhua; Wang, Zhi, E-mail: drzwang@gmail.com; Yue, Wu, E-mail: drwuyue@gmail.com

    2014-02-28

    Highlights: • RAD18 is an important mediator of the IR-induced resistance in glioma cell lines. • RAD18 overexpression confers resistance to IR-mediated apoptosis. • The elevated expression of RAD18 is associated with recurrent GBM who underwent IR therapy. - Abstract: Radioresistance remains a major challenge in the treatment of glioblastoma multiforme (GBM). RAD18 a central regulator of translesion DNA synthesis (TLS), has been shown to play an important role in regulating genomic stability and DNA damage response. In the present study, we investigate the relationship between RAD18 and resistance to ionizing radiation (IR) and examined the expression levels of RAD18 in primary and recurrent GBM specimens. Our results showed that RAD18 is an important mediator of the IR-induced resistance in GBM. The expression level of RAD18 in glioma cells correlates with their resistance to IR. Ectopic expression of RAD18 in RAD18-low A172 glioma cells confers significant resistance to IR treatment. Conversely, depletion of endogenous RAD18 in RAD18-high glioma cells sensitized these cells to IR treatment. Moreover, RAD18 overexpression confers resistance to IR-mediated apoptosis in RAD18-low A172 glioma cells, whereas cells deficient in RAD18 exhibit increased apoptosis induced by IR. Furthermore, knockdown of RAD18 in RAD18-high glioma cells disrupts HR-mediated repair, resulting in increased accumulation of DSB. In addition, clinical data indicated that RAD18 was significantly higher in recurrent GBM samples that were exposed to IR compared with the corresponding primary GBM samples. Collectively, our findings reveal that RAD18 may serve as a key mediator of the IR response and may function as a potential target for circumventing IR resistance in human GBM.

  2. Role of dissolved oxygen reduction in improvement inhibition performance of ascorbic acid during copper corrosion in 0.50 mol/L sulphuric acid

    Mohammed; A.Amin

    2010-01-01

    The kinetics of dissolved O_2 reduction and hydrogen evolution reactions on copper surface was studied in naturally aerated and air and O_2-saturated 0.50 mol/L H_2SO_4 solutions using polarization measurements combined with the rotating disc electrode (RDE).The Koutecky-Levich plot indicated that the dissolved O_2 reduction at the copper electrode was an apparent four-electron process.A correlation between the presence of dissolved O_2 and the formation of Cu_2O,confirmed from XRD,was discussed. Ascorbi...

  3. HiRadMat High Intensity Beam Commissioning

    Blanco Sancho, J; Cornelis, K; Goddard, B; Hessler, C; Jensen, L; Kain, V; Meddahi, M; Theis, C; Vincke, H; Vojtyla, P; Wenninger, J

    2011-01-01

    On Wednesday 14 September and Monday 19 September 2011, high intensity proton beam was sent for the first time down the HiRadMat primary beam line (thereafter TT66), onto the beam dump located in the HiRadMat experimental cavern. This high intensity beam commissioning followed a first period of low intensity beam commissioning which took place in June 2011. During the low intensity beam commissioning, it was checked that all beam line equipment operated as specified. Energy matching and beam steering were performed; optics checks did not reveal any optical errors. Aperture measurements confirmed that there were no bottlenecks. Radiation protection monitoring worked as expected and the measurements were within expectation [1]. With the completion of the HiRadMat ventilation system, the high intensity beam commissioning could successfully continue in September 2011. The main outcome is reported in this note.

  4. RadCat 3.0 user guide.

    Hinojosa, Daniel; Penisten, Janelle J.; Dennis, Matthew L.; Osborn, Douglas M.; Weiner, Ruth F.; Heames, Terence John; Marincel, Michelle K.

    2009-05-01

    RADTRAN is an internationally accepted program and code for calculating the risks of transporting radioactive materials. The first versions of the program, RADTRAN I and II, were developed for NUREG-0170 (USNRC, 1977), the first environmental statement on transportation of radioactive materials. RADTRAN and its associated software have undergone a number of improvements and advances consistent with improvements in both available data and computer technology. The version of RADTRAN currently bundled with RadCat is RADTRAN 6.0. This document provides a detailed discussion and a guide for the use of the RadCat 3.0 Graphical User Interface input file generator for the RADTRAN code. RadCat 3.0 integrates the newest analysis capabilities of RADTRAN 6.0 which includes an economic model, updated loss-of-lead shielding model, and unit conversion. As of this writing, the RADTRAN version in use is RADTRAN 6.0.

  5. Performance of the Harshaw DXT-RAD (TLD-100) dosemeter

    Moor, D.M. [Defence Science and Technology Laboratory, Environmental Sciences Department, Alverstoke, Gosport, Hants PO12 2DL (United Kingdom)], E-mail: dmoor@dstl.gov.uk; Horspool, B.; Stokes, R.P. [Defence Science and Technology Laboratory, Environmental Sciences Department, Alverstoke, Gosport, Hants PO12 2DL (United Kingdom)

    2008-02-15

    The Defence Science and Technology Laboratory (Dstl) has type-tested the Harshaw DXT-RAD dosemeter against the International Standard ISO 12794:2000(E) 'Individual thermoluminescence dosemeters for extremities and eyes' [International Organization for Standardization, 2000. International Standard ISO 12794:2000(E). Nuclear energy-radiation protection-individual thermoluminescence dosemeters for extremities and eyes]. The tests carried out included batch homogeneity, reproducibility, linearity, detection threshold, environmental stability (temperature, humidity and light), self irradiation, isotropy, energy response, dose-rate response and neutron response. The DXT-RAD dosemeter satisfied all the requirements of ISO 12794:2000(E), with the exception of its response at low photon energies and intermediate beta energies. However, it should be noted that other forms of the DXT-RAD dosemeter with a thinner entrance window are available to give an improved response to low-energy radiations.

  6. Molecular Basis for Enhancement of the Meiotic DMCI Recombinase by RAD51AP1

    Dray, Eloise; Dunlop, Myun Hwa; Kauppi, Liisa; San Filippo, Joseph San; Wiese, Claudia; Tsai, Miaw-Sheue; Begovic, Sead; Schild, David; Jasin, Maria; Keeney, Scott; Sung, Patrick

    2010-11-05

    Homologous recombination is needed for meiotic chromosome segregation, genome maintenance, and tumor suppression. RAD51AP1 (RAD51 Associated Protein 1) has been shown to interact with and enhance the recombinase activity of RAD51. Accordingly, genetic ablation of RAD51AP1 leads to enhanced sensitivity to and also chromosome aberrations upon DNA damage, demonstrating a role for RAD51AP1 in mitotic homologous recombination. Here we show physical association of RAD51AP1 with the meiosis-specific recombinase DMC1 and a stimulatory effect of RAD51AP1 on the DMC1-mediated D-loop reaction. Mechanistic studies have revealed that RAD51AP1 enhances the ability of the DMC1 presynaptic filament to capture the duplex DNA partner and to assemble the synaptic complex, in which the recombining DNA strands are homologously aligned. We also provide evidence that functional co-operation is dependent on complex formation between DMC1 and RAD51AP1, and that distinct epitopes in RAD51AP1 mediate interactions with RAD51 and DMC1. Finally, we show that RAD51AP1 is expressed in mouse testes, and that RAD51AP1 foci co-localize with a subset of DMC1 foci in spermatocytes. These results suggest that RAD51AP1 also serves an important role in meiotic homologous recombination.

  7. Rad54 functions as a Heteroduplex DNA Pump Modulated by Its DNA Substrates and Rad51 during D-loop Formation in Homologous Recombination

    Wright, William Douglass; Heyer, Wolf-Dietrich

    2014-01-01

    The displacement loop (D-loop) is the product of homology search and DNA strand invasion, constituting a central intermediate in homologous recombination (HR). In eukaryotes, Rad51 recombinase is assisted in D-loop formation by the Rad54 motor protein. Curiously, Rad54 also disrupts D-loops. How these opposing activities are coordinated toward productive recombination is unknown. Moreover, a seemingly disparate function Rad54 is removal of Rad51 from heteroduplex DNA (hDNA) to allow HR-associ...

  8. Structural and functional evidence that Rad4 competes with Rad2 for binding to the Tfb1 subunit of TFIIH in NER

    Lafrance-Vanasse, Julien; Arseneault, Geneviève; Cappadocia, Laurent; Legault, Pascale; Omichinski, James G.

    2013-01-01

    XPC/Rad4 (human/yeast) recruits transcription faction IIH (TFIIH) to the nucleotide excision repair (NER) complex through interactions with its p62/Tfb1 and XPB/Ssl2 subunits. TFIIH then recruits XPG/Rad2 through interactions with similar subunits and the two repair factors appear to be mutually exclusive within the NER complex. Here, we show that Rad4 binds the PH domain of the Tfb1 (Tfb1PH) with high affinity. Structural characterization of a Rad4–Tfb1PH complex demonstrates that the Rad4-b...

  9. HiRadMat Low Intensity Beam Commissioning

    Blanco Sancho, J; Cornelis, K; Goddard, B; Hessler, C; Jensen, L; Kain, V; Meddahi, M; Theis, C; Vojtyla, P; Wenninger, J

    2011-01-01

    On Wednesday 22 June 2011, proton beam was sent for the first time through the HiRadMat primary beam line, onto the beam dump located in the HiRadMat experimental cavern. The aims of the beam commissioning were to check the beam line geometry and design validity, the correct functioning of all beam line equipment and to verify the beam parameters. At the first trial, the proton beam reached the end of the primary beam line and the preliminary checks allowed confirming that all beam equipment and parameters are within the specification.

  10. Misregulation of Rad50 expression in melanoma cells

    Avaritt, Nathan L.; Owens, Richard; Larson, Signe K.; Reynolds, Matthew; Byrum, Stephanie; Kim M Hiatt; Smoller, Bruce R; Tackett, Alan J.; Cheung, Wang L.

    2012-01-01

    DNA double-strand breaks are increased in human melanoma tissue as detected by histone H2AX phosphorylation1,2,3. We investigated two of the downstream effectors of DNA double-strand breaks, Rad50 and 53BP1 (tumor suppressor p53 binding protein 1), to determine if they are altered in human primary melanoma cells. Melanoma cases demonstrated high Rad50 staining (81.8%; 9/11) significantly more frequently than conventional or atypical melanocytic nevi (0%; 0/18). In contrast, the staining patte...

  11. Effect of bacterial RecA expression on DNA repair in the rad51 and rad52 on DNA mutants of Saccharomyces cerevisiae

    Molecular and functional homology between yeast proteins pRad51 and pRad52 and Escherichia coli p RecA involved in re combinational DNA repair led us to investigate possible effects of reA gene expression on DNA repair in rad51 and rad52 mutants of Saccharomyces cerevisiae. The mutant cells were subjected to one of the following treatments: preincubation with 8-methoxypsoralen and subsequent irradiation with 360-nm ultraviolet (UVA) (8-MOP + UVA), irradiation with 254-nm UV light or treatment with methyl methane sulfonate (MMS). While RecA expression did not repair lethal DNA lesions in mutant rad51, it was able to partially restore resistance to 8-MOP + UVA and MMS in rad52. Expression of recA could not complement the sensitivity of rad51rad52 double mutants, indicating that pRad51 may be essential for the repair-stimulating activity of pRecA in the rad52 mutant. Spontaneous mutagenesis was increased, and 8-MOP-photoinduced mutagenesis in rad51. Thus, pRecA may function in yeast DNA repair either as a member of a protein complex or as an individual protein that binds to mutagen-damaged DNA. (author)

  12. Synthesis, structure and characterisation of Fe0.50Ti2(PO4)3: A new material with Nasicon-like structure

    A new iron titanyl phosphate Fe0.50Ti2(PO4)3 was synthesized by both solid-state reaction and Cu2+-Fe2+ ion exchange method. The material was then characterized by X-ray diffraction, Mossbauer, magnetic susceptibility measurements and optical absorption. The crystal structure of the compound was refined, using X-ray powder diffraction data, by the Rietveld profile method; it crystallizes in the rhombohedral system, space group R3-bar, with a=8.511(1)A and c=20.985(3)A, V=1316.45(3)A3 and Z=6. The structure, which is compared to that of Mn0.50Ti2(PO4)3 is built up from [TiO6] octahedra and [PO4] tetrahedra which are linked by corner sharing along the c-axis. Fe2+ cations are located in half of the antiprism MI sites and are orderly distributed with vacancies within the two possible positions of the MI sites of R3-bar. These results were supported by the Mossbauer studies that showed the presence of one Fe2+ site in the high spin state (t2g4eg2). The Curie-Weiss-type behavior is observed in the magnetic susceptibility. Diffuse reflectance spectrum indicates the presence of octahedrally coordinated Fe2+ ions

  13. Magnetic properties of the alloys system CuAl1-xCrxS2 (x = 0.50, 0.75)

    The synthesis, structural characterization and magnetic properties of alloy system CuAl1-xCrxS2 (x = 0.50, 075) are reported. The samples were synthesized by using the direct fusion technique. The chemical analysis (EDX) confirmed the stoichiometric ratio for the concentrations. The powder diffraction patterns were indexed and the principal phases crystallizes with tetragonal symmetry with unit cell parameters a = 5.312(1) A, c = 10.389(2) A for x = 0.50 and a = 5.314(2) A, c = 10.393(2) A for x = 0.75. These alloys behave as antiferromagnetic, with Neel temperature of 37 K and 39 K, respectively. The EPR linewidth for these alloys shows a paramagnetic behavior between 100 and 610 K. The resonance field and the g factor show a slight variation with temperature. These results are discussed in terms of nearest-neighbor Cr+3 (S=3/2) spin-coupled pairs. (Author)

  14. Hybridization Capture Using RAD Probes (hyRAD, a New Tool for Performing Genomic Analyses on Collection Specimens.

    Tomasz Suchan

    Full Text Available In the recent years, many protocols aimed at reproducibly sequencing reduced-genome subsets in non-model organisms have been published. Among them, RAD-sequencing is one of the most widely used. It relies on digesting DNA with specific restriction enzymes and performing size selection on the resulting fragments. Despite its acknowledged utility, this method is of limited use with degraded DNA samples, such as those isolated from museum specimens, as these samples are less likely to harbor fragments long enough to comprise two restriction sites making possible ligation of the adapter sequences (in the case of double-digest RAD or performing size selection of the resulting fragments (in the case of single-digest RAD. Here, we address these limitations by presenting a novel method called hybridization RAD (hyRAD. In this approach, biotinylated RAD fragments, covering a random fraction of the genome, are used as baits for capturing homologous fragments from genomic shotgun sequencing libraries. This simple and cost-effective approach allows sequencing of orthologous loci even from highly degraded DNA samples, opening new avenues of research in the field of museum genomics. Not relying on the restriction site presence, it improves among-sample loci coverage. In a trial study, hyRAD allowed us to obtain a large set of orthologous loci from fresh and museum samples from a non-model butterfly species, with a high proportion of single nucleotide polymorphisms present in all eight analyzed specimens, including 58-year-old museum samples. The utility of the method was further validated using 49 museum and fresh samples of a Palearctic grasshopper species for which the spatial genetic structure was previously assessed using mtDNA amplicons. The application of the method is eventually discussed in a wider context. As it does not rely on the restriction site presence, it is therefore not sensitive to among-sample loci polymorphisms in the restriction sites

  15. Predicting error in detecting mammographic masses among radiology trainees using statistical models based on BI-RADS features

    Grimm, Lars J., E-mail: Lars.grimm@duke.edu; Ghate, Sujata V.; Yoon, Sora C.; Kim, Connie [Department of Radiology, Duke University Medical Center, Box 3808, Durham, North Carolina 27710 (United States); Kuzmiak, Cherie M. [Department of Radiology, University of North Carolina School of Medicine, 2006 Old Clinic, CB No. 7510, Chapel Hill, North Carolina 27599 (United States); Mazurowski, Maciej A. [Duke University Medical Center, Box 2731 Medical Center, Durham, North Carolina 27710 (United States)

    2014-03-15

    Purpose: The purpose of this study is to explore Breast Imaging-Reporting and Data System (BI-RADS) features as predictors of individual errors made by trainees when detecting masses in mammograms. Methods: Ten radiology trainees and three expert breast imagers reviewed 100 mammograms comprised of bilateral medial lateral oblique and craniocaudal views on a research workstation. The cases consisted of normal and biopsy proven benign and malignant masses. For cases with actionable abnormalities, the experts recorded breast (density and axillary lymph nodes) and mass (shape, margin, and density) features according to the BI-RADS lexicon, as well as the abnormality location (depth and clock face). For each trainee, a user-specific multivariate model was constructed to predict the trainee's likelihood of error based on BI-RADS features. The performance of the models was assessed using area under the receive operating characteristic curves (AUC). Results: Despite the variability in errors between different trainees, the individual models were able to predict the likelihood of error for the trainees with a mean AUC of 0.611 (range: 0.502–0.739, 95% Confidence Interval: 0.543–0.680,p < 0.002). Conclusions: Patterns in detection errors for mammographic masses made by radiology trainees can be modeled using BI-RADS features. These findings may have potential implications for the development of future educational materials that are personalized to individual trainees.

  16. Predicting error in detecting mammographic masses among radiology trainees using statistical models based on BI-RADS features

    Purpose: The purpose of this study is to explore Breast Imaging-Reporting and Data System (BI-RADS) features as predictors of individual errors made by trainees when detecting masses in mammograms. Methods: Ten radiology trainees and three expert breast imagers reviewed 100 mammograms comprised of bilateral medial lateral oblique and craniocaudal views on a research workstation. The cases consisted of normal and biopsy proven benign and malignant masses. For cases with actionable abnormalities, the experts recorded breast (density and axillary lymph nodes) and mass (shape, margin, and density) features according to the BI-RADS lexicon, as well as the abnormality location (depth and clock face). For each trainee, a user-specific multivariate model was constructed to predict the trainee's likelihood of error based on BI-RADS features. The performance of the models was assessed using area under the receive operating characteristic curves (AUC). Results: Despite the variability in errors between different trainees, the individual models were able to predict the likelihood of error for the trainees with a mean AUC of 0.611 (range: 0.502–0.739, 95% Confidence Interval: 0.543–0.680,p < 0.002). Conclusions: Patterns in detection errors for mammographic masses made by radiology trainees can be modeled using BI-RADS features. These findings may have potential implications for the development of future educational materials that are personalized to individual trainees

  17. The tumor suppressor homolog in fission yeast, myh1+, displays a strong interaction with the checkpoint gene rad1+

    The DNA glycosylase MutY is strongly conserved in evolution, and homologs are found in most eukaryotes and prokaryotes examined. This protein is implicated in repair of oxidative DNA damage, in particular adenine mispaired opposite 7,8-dihydro-8-oxoguanine. Previous investigations in Escherichia coli, fission yeast, and mammalian cells show an association of mutations in MutY homologs with a mutator phenotype and carcinogenesis. Eukaryotic MutY homologs physically associate with several proteins with a role in replication, DNA repair, and checkpoint signaling, specifically the trimeric 9-1-1 complex. In a genetic investigation of the fission yeast MutY homolog, myh1+, we show that the myh1 mutation confers a moderately increased UV sensitivity alone and in combination with mutations in several DNA repair genes. The myh1 rad1, and to a lesser degree myh1 rad9, double mutants display a synthetic interaction resulting in enhanced sensitivity to DNA damaging agents and hydroxyurea. UV irradiation of myh1 rad1 double mutants results in severe chromosome segregation defects and visible DNA fragmentation, and a failure to activate the checkpoint. Additionally, myh1 rad1 double mutants exhibit morphological defects in the absence of DNA damaging agents. We also found a moderate suppression of the slow growth and UV sensitivity of rhp51 mutants by the myh1 mutation. Our results implicate fission yeast Myh1 in repair of a wider range of DNA damage than previously thought, and functionally link it to the checkpoint pathway

  18. Rad-hard embedded computers for nuclear robotics

    Nuclear industries require robots with embedded rad hard electronics and high reliability. The SYROCO research program allowed to perform efficient industrial prototypes, build according to MICADO architecture, and to design CADMOS architecture. MICADO architecture uses the auto healing property that have CMOS circuits when being switched off during irradiation. (D.L.). 8 refs., 5 figs

  19. Photoemission studies of As{sub x}Se{sub 100-x} (x: 0, 50, 100) films prepared by pulsed-laser deposition-the effect of annealing

    Siokou, A [Foundation of Research and Technology Hellas-Institute of Chemical Engineering and High Temperature Chemical Processes (FORTH/ICE-HT), PO Box 1414, GR-26504, Rio, Patras (Greece); Kalyva, M [Foundation of Research and Technology Hellas-Institute of Chemical Engineering and High Temperature Chemical Processes (FORTH/ICE-HT), PO Box 1414, GR-26504, Rio, Patras (Greece); Yannopoulos, S N [Foundation of Research and Technology Hellas-Institute of Chemical Engineering and High Temperature Chemical Processes (FORTH/ICE-HT), PO Box 1414, GR-26504, Rio, Patras (Greece); Frumar, M [Department of General and Inorganic Chemistry and Research Center, University of Pardubice, Legions Square 565, Pardubice 53210 (Czech Republic); Nemec, P [Department of General and Inorganic Chemistry and Research Center, University of Pardubice, Legions Square 565, Pardubice 53210 (Czech Republic)

    2006-06-14

    Annealing-induced structural changes in amorphous films As{sub x}Se{sub 100-x} (x: 0, 50, 100) prepared by pulsed laser deposition (PLD) on Si substrates were studied by x-ray and ultraviolet photoelectron spectroscopies (XPS, UPS). For x = 50, the analysis of the XPS As 3d peak revealed three distinct local environments in which the As atoms participate in the as-prepared films. The combination of photoemission and work function measurements showed that annealing close to the glass transition temperature induces atomic rearrangements towards the formation of a more homogenous surface composition as well as to a more energetically favoured film structure, by cleavage of the weaker As-As and Se-Se bonds towards the formation of As-Se ones analogously to As-S system films.

  20. Synthesis, structure, magnetic susceptibility and Mossbauer and Raman spectroscopies of the new oxyphosphate Fe0.50TiO(PO4)

    A new iron titanyl oxyphosphate Fe0.50TiO(PO4) was synthesized by both solid-state reaction and Cu2+-Fe2+ ion exchange method. The material was then characterized by X-ray diffraction, Mossbauer spectroscopy, magnetic susceptibility measurements and Raman spectroscopy. The crystal structure of the compound was refined, using X-ray powder diffraction data, by Rietveld profile method; it crytallizes in the monoclinic system, space group P21/c (No.14), with a=7.4039(3)A, b=7.3838(3)A, c=7.4083(3)A, β=120.36o(1), V=349.44(2)A3 and Z=4. The volume of the title compound is comparable to those of the M0.50IITiO(PO4) series, where MII=Mg, Co, Ni and Zn. The framework is built up from [TiO6] octahedra and [PO4] tetrahedra. [TiO6] octahedra are linked together by corners and form infinite chains along the c-axis. Ti atoms are displaced from the center of octahedral units showing an alternating short distance (1.73A) and a long one (2.22A). These chains are linked together by [PO4] tetrahedra. Fe2+ cations occupy a triangle-based antiprism sharing two faces with two [TiO6] octahedra. Mossbauer and magnetic measurements show the existence of iron only in divalent state, located exclusively in octahedral sites with high spin configuration (t2g4eg2). Raman study confirms the existence of Ti-O-Ti chains

  1. Effects of the rad52 gene on recombination in Saccharomyces cerevisiae

    Effects of the rad52 mutation in Saccharomyces cerevisiae on meiotic, γ-ray-induced, uv-induced, and spontaneous mitotic recombination were studied. The rad52/rad52 diploids undergo premeiotic DNA synthesis; sporulation occurs but inviable spores are produced. Intra- and intergenic recombination during meiosis were examined in cells transferred from sporulation medium to vegetative medium at different time intervals. No intragenic recombination was observed at the hisl-1/hisl-315 and trp5-2/trp5-48 heteroalleles. Gene-centromere recombination was also not observed in rad52/rad52 diploids. No γ-ray-induced intragenic mitotic recombination is seen in rad52/rad52 diploids and uv-induced intragenic recombination is greatly reduced. However, spontaneous mitotic recombination is not similarly affected. The RAD52 gene thus functions in recombination in meiosis and in γ-ray and uv-induced mitotic recombination but not in spontaneous mitotic recombination

  2. Interactions between mutations for sensitivity to psoralen photoaddition (pso) and to radiation (rad) in Saccharomyces cerevisiae.

    Henriques, J A; Moustacchi, E

    1981-01-01

    The mode of interaction in haploid Saccharomyces cerevisiae of two pso mutations with each other and with rad mutations affected in their excision-resynthesis (rad3), error-prone (rad6), and deoxyribonucleic acid double-strand break (rad52) repair pathways was determined for various double mutant combinations. Survival data for 8-methoxypsoralen photoaddition, 254-nm ultraviolet light and gamma rays are presented. For 8-methoxypsoralen photoaddition, which induces both deoxyribonucleic acid i...

  3. Enhanced electric property and magneto-capacitance co-efficient co-related with modulated Raman spectroscopy of GaFeO3 in (GaFeO3)0.50(Ni0.40Zn0.40Cu0.20Fe2O4)0.50

    Highlights: • Dielectric property of (GaFeO3)0.50(Ni0.40Zn0.40Cu0.20Fe2O4)0.50 (GFO-NZCF). • Enhanced magneto-electric property of GFO-NZCF. • Raman effect in GFO-NZCF. • Magneto-capacitance co-efficient has been enhanced in GFO-NZCF. • Ferroelectric to paraelectric transition at ∼680 K of GFO-NZCF. - Abstract: Multiferroic (MF) nanoparticles of GaFeO3 (GFO) were prepared by sol–gel method. To modulate the magneto-dielectric property, nanoparticles of GFO are incorporated in Ni0.40Zn0.40Cu0.20Fe2O4 (NZCF). Crystallographic phases of all the samples are confirmed by analyzing the X-ray diffractograms using FULLPROF program. The hysteretic behavior observed in the polarization vs. electric field loops recorded at room temperature (RT) confirmed the ferroelectric ordering of GFO and (GaFeO3)0.50(Ni0.40Zn0.40Cu0.20Fe2O4)0.50 (GFO-NZCF). Temperature dependent dielectric constant of GFO and GFO-NZCF shows the ferroelectric to paraelectric transition at 625 and 680 K, respectively. The dielectric constant measured in presence and absence of magnetic field confirmed that the samples are MFs with positive magneto-capacitance (MC) co-efficient. Interestingly, electric polarization and MC co-efficient of GFO are increased in GFO-NZCF. Room temperature Raman spectra of GFO and NZCF have been compared with that of GFO-NZCF and the observed changes have been co-related with the enhanced polarization of GFO-NZCF

  4. Rad Hard Active Media For Calorimeters

    Norbeck, E; Möller, A; Onel, Y

    2006-01-01

    Zero-degree calorimeters have limited space and extreme levels of radiation. A simple, low cost, radiation hard design uses tungstenmetal as the absorber and a suitable liquid as the ˇCerenkov radiator. In other applications a PPAC (Parallel Plate Avalanche Counter) operatingwith a suitable atmosphericpressure gas is an attractive active material for a calorimeter. It can be made radiation hard and has sufficient gain in the gas that no electronic components are needed near the detector. It works well even with the highest concentration of shower particles. For this pressure range, R134A (used in auto air conditioners) has many desirable features.

  5. ATP-dependent and independent functions of Rad54 in genome maintenance

    S. Agarwal (Sheba); W.A. van Cappellen (Gert); A. Guénolé (Aude); B. Eppink (Berina); S.E.V. Linsen (Sam); E. Meijering (Erik); A.B. Houtsmuller (Adriaan); R. Kanaar (Roland); J. Essers (Jeroen)

    2011-01-01

    textabstractRad54, a member of the SWI/SNF protein family of DNA-dependent ATPases, repairs DNA double-strand breaks (DSBs) through homologous recombination. Here we demonstrate that Rad54 is required for the timely accumulation of the homologous recombination proteins Rad51 and Brca2 at DSBs. Becau

  6. Effect of bacterial recA expression on DNA repair in the rad51 and rad52 mutants of Saccharomyces cerevisiae

    M.A. Morais Jr.

    1998-03-01

    Full Text Available Molecular and functional homology between yeast proteins pRad51 and pRad52 and Escherichia coli pRecA involved in recombinational DNA repair led us to investigate possible effects of recA gene expression on DNA repair in rad51 and rad52 mutants of Saccharomyces cerevisiae. The mutant cells were subjected to one of the following treatments: preincubation with 8-methoxypsoralen and subsequent irradiation with 360-nm ultraviolet (UVA (8-MOP + UVA, irradiation with 254-nm UV light or treatment with methyl methane sulfonate (MMS. While recA expression did not repair lethal DNA lesions in mutant rad51, it was able to partially restore resistance to 8-MOP + UVA and MMS in rad52. Expression of recA could not complement the sensitivity of rad51rad52 double mutants, indicating that pRad51 may be essential for the repair-stimulating activity of pRecA in the rad52 mutant. Spontaneous mutagenesis was increased, and 8-MOP-photoinduced mutagenesis was decreased by the presence of pRecA in rad52, whereas pRecA decreased UV-induced mutagenesis in rad51. Thus, pRecA may function in yeast DNA repair either as a member of a protein complex or as an individual protein that binds to mutagen-damaged DNA.A homologia tanto a nível molecular como funcional entre as proteínas de leveduras pRad51 e pRad52 envolvidas na reparação de DNA tipo recombinacional e pRecA de E. coli nos levou a analisar os possíveis efeitos da expressão do gene recA sobre a reparação de DNA nos mutantes rad51 e rad52 de S. cerevisiae após tratamento com 8-MOP + UVA, com UV e com MMS. A expressão de recA não foi capaz de restaurar a reparação das lesões induzidas no DNA do mutante rad51 após tratamento com esses agentes, entretanto ela restaurou parcialmente a resistência ao 8-MOP + UVA e ao MMS no mutante rad52. A expressão de recA não complementou a sensibilidade do duplo mutante rad51rad52, indicando que pRad51 pode ser essencial para estimular a atividade de reparação da p

  7. Lymphoid irradiation in intractable rheumatoid arthritis. A double-blind, randomized study comparing 750-rad treatment with 2,000-rad treatment

    Twenty patients with intractable rheumatoid arthritis were treated with 750-rad or 2,000-rad lymphoid irradiation in a randomized double-blind comparative study. Over a 12-month followup period, there was a significant improvement in 4 of 7 and 6 of 7 standard parameters of disease activity following treatment with 750 rads and 2,000 rads, respectively. Transient, short-term toxicity was less frequent with the lower dose. In both groups, there was a sustained peripheral blood lymphopenia, a selective depletion of T helper (Leu-3a+) lymphocytes, and reduced in vitro mitogen responses. These changes did not occur, however, in synovial fluid. These results suggest that 750-rad lymphoid irradiation is as effective as, but less toxic than, that with 2,000 rads in the management of patients with intractable rheumatoid arthritis

  8. Non-mass-like breast lesions at ultrasonography: Feature analysis and BI-RADS assessment

    Ko, Kai-Hsiung [Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC (China); Hsu, Hsian-He, E-mail: hsianhe@yahoo.com.tw [Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC (China); Yu, Jyh-Cherng [Department of Surgery, Division of General Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC (China); Peng, Yi-Jen [Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC (China); Tung, Ho-Jui [Department of Healthcare Administration, Asia University, Taichung, Taiwan, ROC (China); Chu, Chi-Ming [Section of Health Informatics, Institute of Public Health, National Defense Medical Center and University, Taipei, Taiwan, ROC (China); Chang, Tsun-Hou; Chang, Wei-Chou; Wu, Yu-Cheng; Lin, Yu-Pang; Hsu, Giu-Cheng [Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC (China)

    2015-01-15

    Highlights: • The positive predictive value of an NML lesion on ultrasound ranges from 10 to 79%. • A sizable number of NML malignant lesions are pure DCIS or ILC. • Biopsy is indicated for histopathological diagnosis when an ultrasound NML lesion is recognized. - Abstract: Objective: To analyze the features of non-mass-like (NML) breast lesions on ultrasound (US) and determine their corresponding malignancy rate and to stratify these lesion patterns according to US BI-RADS categories. Materials and methods: One hundred sixty-four consecutive lesions were retrospectively classified into four types according to the US features, the corresponding positive predictive values (PPVs) were obtained. Clinical, imaging, and histopathological findings were reviewed. Results: Among the 164 lesions, 39 (24%) were classified as type Ia, 14 (8%) as type Ib, 39 (24%) as type IIa, 19 (12%) as type IIb, 19 (12%) as type III, and 34 (21%) as type IV. The PPVs for malignancy were 21% for type Ia, 79% for type Ib, 10% for type IIa, 58% for type IIb, 16% for type III, and 21% for type IV. All NML lesions were classified as BI-RADS category 4a (type IIa), 4b (type Ia, III and IV) and 4c (type Ib and IIb) according to their PPVs. There was a significantly higher frequency of malignancy among lesions of type Ib and type IIb compared with the other types (P < 0.01 for each). Lesions with associated calcifications, presence of abnormal axillary nodes, or a mammographic finding of suspected malignancy had a higher probability of malignancy (P < 0.05 for each). Conclusion: US is useful in clarifying the indication for biopsy of NML lesions. The types of US classifications used in our study establish reliable references for the NML patterns when stratified according to the BI-RADS categories.

  9. Non-mass-like breast lesions at ultrasonography: Feature analysis and BI-RADS assessment

    Highlights: • The positive predictive value of an NML lesion on ultrasound ranges from 10 to 79%. • A sizable number of NML malignant lesions are pure DCIS or ILC. • Biopsy is indicated for histopathological diagnosis when an ultrasound NML lesion is recognized. - Abstract: Objective: To analyze the features of non-mass-like (NML) breast lesions on ultrasound (US) and determine their corresponding malignancy rate and to stratify these lesion patterns according to US BI-RADS categories. Materials and methods: One hundred sixty-four consecutive lesions were retrospectively classified into four types according to the US features, the corresponding positive predictive values (PPVs) were obtained. Clinical, imaging, and histopathological findings were reviewed. Results: Among the 164 lesions, 39 (24%) were classified as type Ia, 14 (8%) as type Ib, 39 (24%) as type IIa, 19 (12%) as type IIb, 19 (12%) as type III, and 34 (21%) as type IV. The PPVs for malignancy were 21% for type Ia, 79% for type Ib, 10% for type IIa, 58% for type IIb, 16% for type III, and 21% for type IV. All NML lesions were classified as BI-RADS category 4a (type IIa), 4b (type Ia, III and IV) and 4c (type Ib and IIb) according to their PPVs. There was a significantly higher frequency of malignancy among lesions of type Ib and type IIb compared with the other types (P < 0.01 for each). Lesions with associated calcifications, presence of abnormal axillary nodes, or a mammographic finding of suspected malignancy had a higher probability of malignancy (P < 0.05 for each). Conclusion: US is useful in clarifying the indication for biopsy of NML lesions. The types of US classifications used in our study establish reliable references for the NML patterns when stratified according to the BI-RADS categories

  10. Identification of a chicken RAD52 homologue suggests conservation of the RAD52 recombination pathway throughout the evolution of higher eukaryotes.

    Bezzubova, O Y; Schmidt, H.; Ostermann, K.; Heyer, W D; Buerstedde, J M

    1993-01-01

    Degenerate oligonucleotides encoding conserved regions of the Rad52 protein of S. cerevisiae and its homologue, the Rad22 protein of S. pombe, were used to clone a chicken RAD52 counterpart by the polymerase chain reaction. Sequence comparison of the chicken and yeast proteins reveals a strongly conserved region between positions 40 and 178 of the chicken Rad52 sequence indicating that this part of the protein is under strong evolutionary pressure. The first 39 amino acids and the 3' end of t...

  11. Ejecta model development at pRad (u)

    Buttler, William T [Los Alamos National Laboratory; Oro, David M [Los Alamos National Laboratory; Dimonte, Guy [Los Alamos National Laboratory; Terrones, Guillermo [Los Alamos National Laboratory; Morris, Christopher [Los Alamos National Laboratory; Bainbridge, J R [Los Alamos National Laboratory; Hogan, Gary E. [Los Alamos National Laboratory; Hollander, Brian J. [Los Alamos National Laboratory; Holtkamp, David B. [Los Alamos National Laboratory; Kwiathowski, Kris [Los Alamos National Laboratory; Marr-Lyon, Mark [Los Alamos National Laboratory; Mariam, Fesseha G. [Los Alamos National Laboratory; Merrill, Frank E [Los Alamos National Laboratory; Nedrow, Paul [Los Alamos National Laboratory; Saunders, Alexander [Los Alamos National Laboratory; Schwartz, C L [Los Alamos National Laboratory; Stone, B [Los Alamos National Laboratory; Tupa, Dale [Los Alamos National Laboratory; Vogan-McNeil, Wendy S [Los Alamos National Laboratory

    2010-02-09

    In July 2009 we fielded three explosively (HE) driven Richtmyer-Meshkov instability experiments at the LANSCE Proton Radiography Facility (pRad), and in August of 2009 we fielded one flyer plate experiment on the pRad 40 mm powder gun. One HE experiment was done in vacuum, and the other two within four atmospheres of noble gasses: Xe and Ne. These two gases were chosen to study the viscous effects on ejecta formation. It is unexpected, but the viscosity {eta} of Ne is twice that of Xe, and, due to the atomic mass difference between the two, the kinematic viscosity ({eta}/{rho}) of Ne is about ten times that of Xe. The results showed that ejecta formation is sensitively linked to the gas density, which implies that the Weber number is more important in ejecta formation than the Reynolds number.

  12. Low anterior anastomotic dehiscence following preoperative irradiation with 6000 rads

    Blake, D.P.; Bubrick, M.P.; Kochsiek, G.G.; Feeney, D.A.; Johnston, G.R.; Strom, R.L.; Hitchcock, C.R.

    1984-03-01

    Twenty mongrel dogs received 6000 rads of irradiation to the rectum and colon using the Nominal Standard Dosage Equation. Three weeks after irradiation each dog underwent anterior resection of the rectosigmoid with reconstruction randomized to either an EEA stapled or a two layer handsewn anastomosis. Each dog was studied digitally and by barium enema at the time of surgery, on the seventh postoperative day, and at autopsy. Five clinically significant leaks and three radiographic leaks occurred in the EEA stapled anastomoses. The handsewn anastomoses had five clinically significant leaks and two radiographic leaks. The data indicate that low anterior resection with either an EEA stapled or handsewn anastomosis cannot be done safely after 6000 rad preoperative irradiation.

  13. Low anterior anastomotic dehiscence following preoperative irradiation with 6000 rads

    Twenty mongrel dogs received 6000 rads of irradiation to the rectum and colon using the Nominal Standard Dosage Equation. Three weeks after irradiation each dog underwent anterior resection of the rectosigmoid with reconstruction randomized to either an EEA stapled or a two layer handsewn anastomosis. Each dog was studied digitally and by barium enema at the time of surgery, on the seventh postoperative day, and at autopsy. Five clinically significant leaks and three radiographic leaks occurred in the EEA stapled anastomoses. The handsewn anastomoses had five clinically significant leaks and two radiographic leaks. The data indicate that low anterior resection with either an EEA stapled or handsewn anastomosis cannot be done safely after 6000 rad preoperative irradiation

  14. Accurate Crystal Structure Refinement of La3Ta0.25Zr0.50Ga5.25O14

    An accurate X-ray diffraction study of a La3Ta0.25Zr0.50Ga5.25O14 single crystal (a = 8.2574(4) A, c = 5.1465(4) A, sp. gr. P321, Z = 1, R/Rw = 0.62/0.57% for 4144 unique reflections and 91 parameters) has been performed with a simultaneous neutron diffraction analysis. Tantalum, zirconium, and gallium atoms are found to occupy the mixed octahedral position (symmetry 32). Gallium atoms and a few zirconium atoms are in the position on axis 2 in the tetrahedron. The tetrahedral position on axis 3 is completely occupied by gallium atoms, while the large polyhedron on axis 2 is occupied by lanthanum atoms. The high resolution and averaging of the results obtained in two independent X-ray experiments with the same sample provided accu- rate structural data, in particular, on the anharmonicity of thermal atomic vibrations (atomic displacements). The X-ray and neutron diffraction data on the atomic displacements are compared.

  15. Rad51 Protein Expression and Survival in Patients with Glioblastoma Multiforme

    Purpose: Treatment of glioblastoma multiforme (GBM) continues to pose a significant therapeutic challenge, with most tumors recurring within the previously irradiated tumor bed. To improve outcomes, we must be able to identify and treat resistant cell populations. Rad51, an enzyme involved in homologous recombinational repair, leads to increased resistance of tumor cells to cytotoxic treatments such as radiotherapy. We hypothesized that Rad51 might contribute to GBM's apparent radioresistance and consequently influence survival. Methods and Materials: A total of 68 patients with an initial diagnosis of GBM were retrospectively evaluated; for 10 of these patients, recurrent tumor specimens were used to construct a tissue microarray. Rad51 protein expression was then correlated with the actual and predicted survival using recursive partitioning analysis. Results: Rad51 protein was elevated in 53% of the GBM specimens at surgery. The Rad51 levels correlated directly with survival, with a median survival of 15 months for patients with elevated Rad51 compared with 9 months for patients with low or absent levels of Rad51 (p = .05). At disease recurrence, 70% of patients had additional increases in Rad51 protein. Increased Rad51 levels at disease recurrence similarly predicted for improved overall survival, with a mean survival of 16 months from the second craniotomy compared with only 4 months for patients with low Rad51 levels (p = .13). Conclusion: Elevated levels of the double-stranded DNA repair protein Rad51 predicted for an increase survival duration in patients with GBM, at both initial tumor presentation and disease recurrence.

  16. RadNet: Open network protocol for radiation data

    Safeguards instrumentation is increasingly being incorporated into remote monitoring applications. In the past, vendors of radiation monitoring instruments typically provided the tools for uploading the monitoring data to a host. However, the proprietary nature of communication protocols lends itself to increased computer support needs and increased installation expenses. As a result, a working group of suppliers and customers of radiation monitoring instruments defined an open network protocol for transferring packets on a local area network from radiation monitoring equipment to network hosts. The protocol was termed RadNet. While it is now primarily used for health physics instruments, RadNet's flexibility and strength make it ideal for remote monitoring of nuclear materials. The incorporation of standard, open protocols ensures that future work will not render present work obsolete; because RadNet utilizes standard Internet protocols, and is itself a non-proprietary standard. The use of industry standards also simplifies the development and implementation of ancillary services, e.g. E-main generation or even pager systems

  17. RadNet: Open network protocol for radiation data

    Rees, B.; Olson, K. [Los Alamos National Lab., NM (United States); Beckes-Talcott, J.; Kadner, S.; Wenderlich, T.; Hoy, M.; Doyle, W. [Aquila Technologies Group, Inc., Albuquerque, NM (United States); Koskelo, M. [Canberra Industries, Meriden, CT (United States)

    1998-12-31

    Safeguards instrumentation is increasingly being incorporated into remote monitoring applications. In the past, vendors of radiation monitoring instruments typically provided the tools for uploading the monitoring data to a host. However, the proprietary nature of communication protocols lends itself to increased computer support needs and increased installation expenses. As a result, a working group of suppliers and customers of radiation monitoring instruments defined an open network protocol for transferring packets on a local area network from radiation monitoring equipment to network hosts. The protocol was termed RadNet. While it is now primarily used for health physics instruments, RadNet`s flexibility and strength make it ideal for remote monitoring of nuclear materials. The incorporation of standard, open protocols ensures that future work will not render present work obsolete; because RadNet utilizes standard Internet protocols, and is itself a non-proprietary standard. The use of industry standards also simplifies the development and implementation of ancillary services, e.g. E-main generation or even pager systems.

  18. Rapid SNP discovery and genetic mapping using sequenced RAD markers.

    Nathan A Baird

    Full Text Available Single nucleotide polymorphism (SNP discovery and genotyping are essential to genetic mapping. There remains a need for a simple, inexpensive platform that allows high-density SNP discovery and genotyping in large populations. Here we describe the sequencing of restriction-site associated DNA (RAD tags, which identified more than 13,000 SNPs, and mapped three traits in two model organisms, using less than half the capacity of one Illumina sequencing run. We demonstrated that different marker densities can be attained by choice of restriction enzyme. Furthermore, we developed a barcoding system for sample multiplexing and fine mapped the genetic basis of lateral plate armor loss in threespine stickleback by identifying recombinant breakpoints in F(2 individuals. Barcoding also facilitated mapping of a second trait, a reduction of pelvic structure, by in silico re-sorting of individuals. To further demonstrate the ease of the RAD sequencing approach we identified polymorphic markers and mapped an induced mutation in Neurospora crassa. Sequencing of RAD markers is an integrated platform for SNP discovery and genotyping. This approach should be widely applicable to genetic mapping in a variety of organisms.

  19. NARAC Dispersion Model Product Integration With RadResponder

    Aluzzi, Fernando [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-09-30

    Work on enhanced cooperation and interoperability of Nuclear Incident Response Teams (NIRT) is a joint effort between DHS/FEMA, DOE/NNSA and EPA. One such effort was the integration between the RadResponder Network, a resource sponsored by FEMA for the management of radiological data during an emergency, and the National Atmospheric Advisory Center (NARAC), a DOE/NNSA modeling resource whose predictions are used to aid radiological emergency preparedness and response. Working together under a FEMA-sponsored project these two radiological response assets developed a capability to read and display plume model prediction results from the NARAC computer system in the RadResponder software tool. As a result of this effort, RadResponder users have been provided with NARAC modeling predictions of contamination areas, radiological dose levels, and protective action areas (e.g., areas warranting worker protection or sheltering/evacuation) to help guide protective action decisions and field monitoring surveys, and gain key situation awareness following a radiological/nuclear accident or incident (e.g., nuclear power plant accident, radiological dispersal device incident, or improvised nuclear detonation incident). This document describes the details of this integration effort.

  20. Radon and Thoron Concentration measurement of Ground water in Kufa City by using RAD7 detector

    Radon (222Rn) and Thoron (220Rn) concentration in the groundwater samples and their annual effective dose exposure were measured in the Kufa city - Iraq.It is measured by Durridge RAD-7 radon-in-air monitor, RAD-H2O new technique with closed loop aeration concept.Study was identified on the map at the city of Kufa, by GIS.It is found that Radon and Thoron concentration in 20 groundwater samples of studied area.The range is between (0.267- 5.662), (0-0.7486)Bq L-1 respectively, the EPA's maximum contaminant level (MCL) of 11.1 Bq L-1.Also, obtain this study independent of groundwater physical and chemical properties such as (PH and EC) on the radon concentration.The total annual effective dose resulting from radon in groundwater of studied samples were significantly lower than the UNSCEAR and WHO recommended limit for members of the public of 1 mSv.y-1

  1. The AtRAD21.1 and AtRAD21.3 Arabidopsis cohesins play a synergistic role in somatic DNA double strand break damage repair

    da Costa-Nunes, J.A.; Capitao, C.; Kozák, Jaroslav; Costa-Nunes, P.; Ducasa, G.M.; Pontes, O.; Angelis, Karel

    2014-01-01

    Roč. 14, DEC 16 2014 (2014). ISSN 1471-2229 R&D Projects: GA MŠk(CZ) LD13006; GA ČR GA13-06595S Institutional support: RVO:61389030 Keywords : Arabidopsis * AtRAD21.1 * AtRAD21.3 Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.813, year: 2014

  2. Disparate requirements for the Walker A and B ATPase motifs ofhuman RAD51D in homologous recombination

    Wiese, Claudia; Hinz, John M.; Tebbs, Robert S.; Nham, Peter B.; Urbin, Salustra S.; Collins, David W.; Thompson, Larry H.; Schild, David

    2006-04-21

    In vertebrates, homologous recombinational repair (HRR) requires RAD51 and five RAD51 paralogs (XRCC2, XRCC3, RAD51B, RAD51C, and RAD51D) that all contain conserved Walker A and B ATPase motifs. In human RAD51D we examined the requirement for these motifs in interactions with XRCC2 and RAD51C, and for survival of cells in response to DNA interstrand crosslinks. Ectopic expression of wild type human RAD51D or mutants having a non-functional A or B motif was used to test for complementation of a rad51d knockout hamster CHO cell line. Although A-motif mutants complement very efficiently, B-motif mutants do not. Consistent with these results, experiments using the yeast two- and three-hybrid systems show that the interactions between RAD51D and its XRCC2 and RAD51C partners also require a functional RAD51D B motif, but not motif A. Similarly, hamster Xrcc2 is unable to bind to the non-complementing human RAD51D B-motif mutants in co-immunoprecipitation assays. We conclude that a functional Walker B motif, but not A motif, is necessary for RAD51D's interactions with other paralogs and for efficient HRR. We present a model in which ATPase sites are formed in a bipartite manner between RAD51D and other RAD51 paralogs.

  3. Physical and microstructural characterization of La0,60Sr0,40Co0,20Fe0,80O3-δ and Ba0,50Sr0,50Co0,80Fe0,20O3-δ ceramics

    The La0,60Sr0,40Co0,20Fe0,80O3-δ (LSCF) and Ba0,50Sr0,50Co0,80Fe0,20O3-δ (BSCF) oxides are studied as cathodes in Solid Oxide Fuel Cell. The objective of this study is to characterize physically and microstructural these materials. The LSCF was synthesized by citrate technique and BSCF for citrates-EDTA, processed under the same conditions. The characterizations of ceramics were performed by X-ray diffraction, dilatometry, scanning electron microscopy and apparent density for Archimedes principle. According to the diffraction technique, confirmed the presence of single phases for LSCF to 800 deg C and BSCF to 900 deg C, with orthorhombic and cubic structures, respectively. For dilatometry were determined the sintering temperatures, near of 1050 deg C to BSCF and 1100 deg C to LSCF. The sintered micrographs at 1000, 1050 and 1100 deg C for 2 hours showed homogeneity microstructure, containing porosity and, attacked thermally, a homogeneous distribution of grains. Finally by bulk density, was estimated porosity between 20 and 30%. (author)

  4. Modulated magneto-dielectric property and exchange bias effect of BiFeO3 incorporated in (BiFeO3)0.50 (Li0.30Zn0.35 Fe2.35O4)0.50 nanocomposite

    Nanoparticles of BiFeO3 (BFO) are prepared by the sol–gel method. These prepared nanoparticles are incorporated in the nanocomposite of (BiFeO3)0.50 (Li0.30Zn0.35 Fe2.35O4)0.50 (BFO-LZFO). The formation of pure crystallographic phase of each component (BFO and LZFO) in the nanocomposite of BFO-LZFO has been confirmed by Rietveld analysis of the X-ray diffractograms using FULLPROF program. Morphology, average particle size and its distribution, crystallographic phase etc. are determined from the high-resolution transmission electron microscopy of BFO-LZFO. Magnetic property of BFO is drastically enhanced in the nanocomposite. An exchange bias effect is also observed in the field cooled and zero field cooled hysteresis loops, which suggest that antiferromagnetic nanoparticles of BFO are encapsulated by ferrimagnetic nanoparticles of LZFO in BFO-LZFO. Magneto-capacitance (MC) co-efficient has been estimated from the values of dielectric constants, measured in presence and absence of magnetic field. Results of magnetic, dielectric and MC co-efficient indicate a strong modulation of magneto-dielectric property of BFO in BFO-LZFO and this would be quite interesting for applications of BFO, a lead free multiferroic

  5. Alterações clínicolaboratoriais em pacientes com malária por Plasmodium vivax e deficiência de glicose-6-fosfato desidrogenase tratados com 0,50mg/kg/dia de primaquina Clinical and laboratorial alterations in Plasmodium vivax malaria patients and glucose-6-phosphate dehydrogenase deficiency treated with primaquine at 0.50mg/kg/day

    Mônica C.M. Silva

    2004-06-01

    Full Text Available O efeito adverso da primaquina na dose de 0,50mg/kg/dia foi investigado em onze pacientes com malária vivax (três com deficiência de glicose-6-fosfato desidrogenase. Alterações clínicas e laboratoriais indicaram hemólise aguda apenas nos enzimopênicos, o que fez com que o tratamento fosse interrompido. Nossos resultados sugerem a necessidade do emprego de um teste de triagem para a deficiência de G6PD em áreas endêmicas de malária vivax a fim de se evitar complicações causadas pelo uso da primaquina.The adverse effects of primaquine (0.50mg/kg/day were investigated in eleven patients with vivax malaria (three patients with glucose-6-phosphate dehydrogenase deficiency. Clinical and laboratorial alterations indicated acute hemolysis in only the enzymopenic patients and treatment was interrupted. Our results suggest that screening for G6PD deficiency should be carried out in patients with vivax malaria infection in order to avoid complications due to primaquine.

  6. Magnetic properties of the alloys system CuAl{sub 1-x}Cr{sub x}S{sub 2} (x = 0.50, 0.75); Propiedades magneticas del sistema de aleaciones CuAl{sub 1-x}Cr{sub x}S{sub 2} (x = 0.50, 0.75)

    Villarreal, M. A.; Grima, P.; Quintero, M.; Moreno, E.; Fernandez, J. [Universidad de los Andes, Facultad de Ciencias, Centro de Estudios en Semiconductores, Departamento de Fisica, Apdo. de Correos No. 1, La Hechicera, 5251 Merida, (Venezuela, Bolivarian Republic of); Silva, P.; Villegas, J., E-mail: mavu@ula.ve [Instituto Venezolano de Investigaciones Cientificas, Laboratorio de Fisica de la Materia Condensada, Centro de Fisica, Carretera Panamericana Km. 11, Apdo. 21827, 1020-A Caracas (Venezuela, Bolivarian Republic of)

    2013-10-01

    The synthesis, structural characterization and magnetic properties of alloy system CuAl{sub 1-x}Cr{sub x}S{sub 2} (x = 0.50, 075) are reported. The samples were synthesized by using the direct fusion technique. The chemical analysis (EDX) confirmed the stoichiometric ratio for the concentrations. The powder diffraction patterns were indexed and the principal phases crystallizes with tetragonal symmetry with unit cell parameters a = 5.312(1) A, c = 10.389(2) A for x = 0.50 and a = 5.314(2) A, c = 10.393(2) A for x = 0.75. These alloys behave as antiferromagnetic, with Neel temperature of 37 K and 39 K, respectively. The EPR linewidth for these alloys shows a paramagnetic behavior between 100 and 610 K. The resonance field and the g factor show a slight variation with temperature. These results are discussed in terms of nearest-neighbor Cr{sup +3} (S=3/2) spin-coupled pairs. (Author)

  7. Interobserver Reproducibility of the PI-RADS Version 2 Lexicon: A Multicenter Study of Six Experienced Prostate Radiologists.

    Rosenkrantz, Andrew B; Ginocchio, Luke A; Cornfeld, Daniel; Froemming, Adam T; Gupta, Rajan T; Turkbey, Baris; Westphalen, Antonio C; Babb, James S; Margolis, Daniel J

    2016-09-01

    Purpose To determine the interobserver reproducibility of the Prostate Imaging Reporting and Data System (PI-RADS) version 2 lexicon. Materials and Methods This retrospective HIPAA-compliant study was institutional review board-approved. Six radiologists from six separate institutions, all experienced in prostate magnetic resonance (MR) imaging, assessed prostate MR imaging examinations performed at a single center by using the PI-RADS lexicon. Readers were provided screen captures that denoted the location of one specific lesion per case. Analysis entailed two sessions (40 and 80 examinations per session) and an intersession training period for individualized feedback and group discussion. Percent agreement (fraction of pairwise reader combinations with concordant readings) was compared between sessions. κ coefficients were computed. Results No substantial difference in interobserver agreement was observed between sessions, and the sessions were subsequently pooled. Agreement for PI-RADS score of 4 or greater was 0.593 in peripheral zone (PZ) and 0.509 in transition zone (TZ). In PZ, reproducibility was moderate to substantial for features related to diffusion-weighted imaging (κ = 0.535-0.619); fair to moderate for features related to dynamic contrast material-enhanced (DCE) imaging (κ = 0.266-0.439); and fair for definite extraprostatic extension on T2-weighted images (κ = 0.289). In TZ, reproducibility for features related to lesion texture and margins on T2-weighted images ranged from 0.136 (moderately hypointense) to 0.529 (encapsulation). Among 63 lesions that underwent targeted biopsy, classification as PI-RADS score of 4 or greater by a majority of readers yielded tumor with a Gleason score of 3+4 or greater in 45.9% (17 of 37), without missing any tumor with a Gleason score of 3+4 or greater. Conclusion Experienced radiologists achieved moderate reproducibility for PI-RADS version 2, and neither required nor benefitted from a training session

  8. Effects of the rad52 gene on recombination in Saccharomyces cerevisiae

    Effects of the rad 52 mutation in Saccharomyces cerevisiae on meiotic, γ-ray-induced, uv-induced and spontaneous mitotic recombination were studied. The rad52/rad52 diploids undergo premeiotic DNA synthesis; sporulation occurs but inviable spores are produced. Both intra and intergenic recombination during meiosis were examined in cells transferred from sporulation medium to vegetative medium at different time intervals. No intragenic recombination was observed at the his1-1/his1-315 and trp-5-2/trp5-48 heteroalleles. Gene-centromere recombination also was not observed in rad/52/rad52 diploids. No γ-ray- or uv-induced intragenic mitotic recombination is seen in rad52/rad52 diploids. The rate of spontaneous mitotic recombination is lowered five-fold at the his1-1/his1-315 and leu1-c/leu1-12 heteroalleles. Spontaneous reversion rates of both his1-1 and his1-315 were elevated 10 to 20 fold in rad52/rad52 diploids. The RAD52 gene function is required for spontaneous mitotic recombination, uv- and γ-ray-induced mitotic recombination and mitotic recombination

  9. RAD6/sup +/ gene of Saccharomyces cerevisiae codes for two mutationally separable deoxyribonucleic acid repair functions

    The response of two mutant alleles of the RAD6/sup +/ gene of Saccharomyces cerevisiae to the ochre translational suppressor SUQ5 was determined. Both the ultraviolet sensitivity phenotype and the deficiency in ultraviolet-induced mutagenesis phenotype of the rad6-1 allelle were suppressed in a [psi/sup +/] background. For the rad6-3 allelle, only the ultraviolet-sensitivity phenotype was suppressible in a [psi/sup +/] background. An SUQ5 rad6-3 [psi/sup +/] strain that was examined showed the normal rad6-3 deficiency in ultraviolet-induced mutagenesis. The authors propose that the RAD6/sup +/ gene is divided into two cistrons, RAD6A and RAD6B. RAD6A codes for an activity responsible for the error-prone repair of ultraviolet-induced lesions in deoxyribonucleic acid but is not involved in a cell's resistance to the lethal effects of ultraviolet light. RAD6B codes for an activity essential for error-free repair of potentially lethal mutagenic damage

  10. RAD24 (=R1/sup S/) gene product of Saccharomyces cerevisiae participates in two different pathways of DNA repair

    The moderately UV- and X-ray-sensitive mutant of Saccharomyces cerevisiae originally designated r1/sup s/ complements all rad and mms mutants available. Therefore, the new nomination rad24-1 according to the RAD nomenclature is suggested. RAD24 maps on chromosome V, close to RAD3 (1.3 cM). In order to associate the RAD24 gene with one of the three repair pathways, double mutants of rad24 and various representative genes of each pathway were constructed. The UV and X-ray sensitivities of the double mutants compared to the single mutants indicate that RAD24 is involved in excision repair of UV damage (RAD3 epistasis group), as well as in recombination repair of UV and X-ray damage (RAD52 epistasis group). Properties of the mutant are discussed which hint at the control of late steps in the pathways

  11. Comparison of Martian Surface Radiation Predictions to the Measurements of Mars Science Laboratory Radiation Assessment Detector (MSL/RAD)

    Kim, Myung-Hee Y.; Cucinotta, Francis A.; Zeitlin, Cary; Hassler, Donald M.; Ehresmann, Bent; Rafkin, Scot C. R.; Wimmer-Schweingruber, Robert F; Boettcher, Stephan; Boehm, Eckart; Guo, Jingnan; Koehler, Jan; Martin, Cesar; Reitz, Guenther; Posner, Erik

    2014-01-01

    For the analysis of radiation risks to astronauts and planning exploratory space missions, detailed knowledge of particle spectra is an important factor. Detailed measurements of the energetic particle radiation environment on the surface of Mars have been made by the Mars Science Laboratory Radiation Assessment Detector (MSL-RAD) on the Curiosity rover since August 2012, and particle fluxes for a wide range of ion species (up to several hundred MeV/u) and high energy neutrons (8 - 1000 MeV) have been available for the first 200 sols. Although the data obtained on the surface of Mars for 200 sols are limited in the narrow energy spectra, the simulation results using the Badhwar-O'Neill galactic cosmic ray (GCR) environment model and the high-charge and energy transport (HZETRN) code are compared to the data. For the nuclear interactions of primary GCR through Mars atmosphere and Curiosity rover, the quantum multiple scattering theory of nuclear fragmentation (QMSFRG) is used, which includes direct knockout, evaporation and nuclear coalescence. Daily atmospheric pressure measurements at Gale Crater by the MSL Rover Environmental Monitoring Station are implemented into transport calculations for describing the daily column depth of atmosphere. Particles impinging on top of the Martian atmosphere reach the RAD after traversing varying depths of atmosphere that depend on the slant angles, and the model accounts for shielding of the RAD by the rest of the instrument. Calculations of stopping particle spectra are in good agreement with the RAD measurements for the first 200 sols by accounting changing heliospheric conditions and atmospheric pressure. Detailed comparisons between model predictions and spectral data of various particle types provide the validation of radiation transport models, and thus increase the accuracy of the predictions of future radiation environments on Mars. These contributions lend support to the understanding of radiation health risks to

  12. Alterações clínicolaboratoriais em pacientes com malária por Plasmodium vivax e deficiência de glicose-6-fosfato desidrogenase tratados com 0,50mg/kg/dia de primaquina Clinical and laboratorial alterations in Plasmodium vivax malaria patients and glucose-6-phosphate dehydrogenase deficiency treated with primaquine at 0.50mg/kg/day

    Mônica C.M. Silva; Eliane B. Santos; Elenild G. Costa; Manoel G. S. Filho; Guerreiro, João F.; Póvoa, Marinete M.

    2004-01-01

    O efeito adverso da primaquina na dose de 0,50mg/kg/dia foi investigado em onze pacientes com malária vivax (três com deficiência de glicose-6-fosfato desidrogenase). Alterações clínicas e laboratoriais indicaram hemólise aguda apenas nos enzimopênicos, o que fez com que o tratamento fosse interrompido. Nossos resultados sugerem a necessidade do emprego de um teste de triagem para a deficiência de G6PD em áreas endêmicas de malária vivax a fim de se evitar complicações causadas pelo uso da pr...

  13. Real-time assembly and disassembly of human RAD51 filaments on individual DNA molecules

    van der Heijden, Thijn; Seidel, Ralf; Modesti, Mauro; Kanaar, Roland; Wyman, Claire; Dekker, Cees

    2007-01-01

    textabstractThe human DNA repair protein RAD51 is the crucial component of helical nucleoprotein filaments that drive homologous recombination. The molecular mechanistic details of how this structure facilitates the requisite DNA strand rearrangements are not known but must involve dynamic interactions between RAD51 and DNA. Here, we report the real-time kinetics of human RAD51 filament assembly and disassembly on individual molecules of both single- and double-stranded DNA, as measured using...

  14. Real-time assembly and disassembly of human RAD51 filaments on individual DNA molecules

    Van der Heijden, T.; Seidel, R.; Modesti, M.; Kanaar, R.; Wyman, C; Dekker, C.

    2007-01-01

    The human DNA repair protein RAD51 is the crucial component of helical nucleoprotein filaments that drive homologous recombination. The molecular mechanistic details of how this structure facilitates the requisite DNA strand rearrangements are not known but must involve dynamic interactions between RAD51 and DNA. Here, we report the real-time kinetics of human RAD51 filament assembly and disassembly on individual molecules of both single- and double-stranded DNA, as measured using magnetic tw...

  15. Mek1 Down Regulates Rad51 Activity during Yeast Meiosis by Phosphorylation of Hed1.

    Callender, Tracy L; Laureau, Raphaelle; Wan, Lihong; Chen, Xiangyu; Sandhu, Rima; Laljee, Saif; Zhou, Sai; Suhandynata, Ray T; Prugar, Evelyn; Gaines, William A; Kwon, YoungHo; Börner, G Valentin; Nicolas, Alain; Neiman, Aaron M; Hollingsworth, Nancy M

    2016-08-01

    During meiosis, programmed double strand breaks (DSBs) are repaired preferentially between homologs to generate crossovers that promote proper chromosome segregation at Meiosis I. In many organisms, there are two strand exchange proteins, Rad51 and the meiosis-specific Dmc1, required for interhomolog (IH) bias. This bias requires the presence, but not the strand exchange activity of Rad51, while Dmc1 is responsible for the bulk of meiotic recombination. How these activities are regulated is less well established. In dmc1Δ mutants, Rad51 is actively inhibited, thereby resulting in prophase arrest due to unrepaired DSBs triggering the meiotic recombination checkpoint. This inhibition is dependent upon the meiosis-specific kinase Mek1 and occurs through two different mechanisms that prevent complex formation with the Rad51 accessory factor Rad54: (i) phosphorylation of Rad54 by Mek1 and (ii) binding of Rad51 by the meiosis-specific protein Hed1. An open question has been why inhibition of Mek1 affects Hed1 repression of Rad51. This work shows that Hed1 is a direct substrate of Mek1. Phosphorylation of Hed1 at threonine 40 helps suppress Rad51 activity in dmc1Δ mutants by promoting Hed1 protein stability. Rad51-mediated recombination occurring in the absence of Hed1 phosphorylation results in a significant increase in non-exchange chromosomes despite wild-type levels of crossovers, confirming previous results indicating a defect in crossover assurance. We propose that Rad51 function in meiosis is regulated in part by the coordinated phosphorylation of Rad54 and Hed1 by Mek1. PMID:27483004

  16. Evaluation of BICRON NE MCP DXT-RAD passive extremity dosemeter

    Yuen, P S; Frketich, G; Rotunda, J

    1999-01-01

    Passive extremity dosemeters currently used in dosimetry communities worldwide have shortcomings. In general, an extremity dosemeter has too thick a detector element, and the dosemeter response is highly energy dependent for beta rays with energies ranging from 200 keV to 2 MeV. It often does not have dosemeter identification, causing problems in the chain of custody. It is often read manually, rendering reading/packing operations very labour intensive. As a result of collaboration between AECL and BICRON NE, a new extremity dosemeter, incorporating a highly sensitive LiF:Mg,Cu,P TLD and tentatively code named MCP DXT-RAD, was developed. It has been evaluated for radiological performance against an ISO draft standard for extremity dosemeters in twelve categories: homogeneity, detection threshold, beta ray energy response, beta angular response, photon energy response, photon angular response, reproducibility, stability under various climatic conditions, linearity, residue, self irradiation, and effect of ligh...

  17. Upward- directed charged particle flux detection in the MSL/RAD instrument

    Appel, Jan Kristoffer; Zeitlin, Cary; Koehler, Jan; Hassler, Donald M.; Rafkin, Scot; Guo, Jingnan; Ehresmann, Bent; Wimmer-Schweingruber, Robert; Matthiä, Daniel; Lohf, Henning

    2016-07-01

    The Mars Science Laboratory rover Curiosity, operating on the surface of Mars, is exposed to radiation fluxes from above and below. Galactic Cosmic Rays travel through the Martian atmosphere, producing a modified spectrum consisting of both primary and secondary particles at ground level. These particles produce an upward- directed secondary particle spectrum as they interact with the Martian soil.These upward- directed particles then pass through the rover and enter the Radiation Assessment Detector onboard the rover from below. Here, we characterize the upward- and downward- directed spectra measured by the detector through a combination of GEANT4 and Planetocosmics simulations. We develop and demonstrate a method to discriminate between upward- and downward- directed particle fluxes during the MSL cruise phase to Mars and the surface science phase. This method enables us to extend the energy range and directionality of RAD beyond its design limits.

  18. Rad9 plays an important role in DNA mismatch repair through physical interaction with MLH1

    He, Wei; Zhao, Yun; Zhang, Chunbo; An, Lili; Hu, Zhishang; Liu, Yuheng; Han, Lu; Bi, Lijun; Xie, Zhensheng; Xue, Peng; Yang, Fuquan; Hang, Haiying

    2008-01-01

    Rad9 is conserved from yeast to humans and plays roles in DNA repair (homologous recombination repair, and base-pair excision repair) and cell cycle checkpoint controls. It has not previously been reported whether Rad9 is involved in DNA mismatch repair (MMR). In this study, we have demonstrated that both human and mouse Rad9 interacts physically with the MMR protein MLH1. Disruption of the interaction by a single-point mutation in Rad9 leads to significantly reduced MMR activity. This disrup...

  19. Germline mutation in the RAD51B gene confers predisposition to breast cancer

    Most currently known breast cancer predisposition genes play a role in DNA repair by homologous recombination. Recent studies conducted on RAD51 paralogs, involved in the same DNA repair pathway, have identified rare germline mutations conferring breast and/or ovarian cancer predisposition in the RAD51C, RAD51D and XRCC2 genes. The present study analysed the five RAD51 paralogs (RAD51B, RAD51C, RAD51D, XRCC2, XRCC3) to estimate their contribution to breast and ovarian cancer predisposition. The study was conducted on 142 unrelated patients with breast and/or ovarian cancer either with early onset or with a breast/ovarian cancer family history. Patients were referred to a French family cancer clinic and had been previously tested negative for a BRCA1/2 mutation. Coding sequences of the five genes were analysed by EMMA (Enhanced Mismatch Mutation Analysis). Detected variants were characterized by Sanger sequencing analysis. Three splicing mutations and two likely deleterious missense variants were identified: RAD51B c.452 + 3A > G, RAD51C c.706-2A > G, RAD51C c.1026 + 5-1026 + 7del, RAD51B c.475C > T/p.Arg159Cys and XRCC3 c.448C > T/p.Arg150Cys. No RAD51D and XRCC2 gene mutations were detected. These mutations and variants were detected in families with both breast and ovarian cancers, except for the RAD51B c.475C > T/p.Arg159Cys variant that occurred in a family with 3 breast cancer cases. This study identified the first RAD51B mutation in a breast and ovarian cancer family and is the first report of XRCC3 mutation analysis in breast and ovarian cancer. It confirms that RAD51 paralog mutations confer breast and ovarian cancer predisposition and are rare events. In view of the low frequency of RAD51 paralog mutations, international collaboration of family cancer clinics will be required to more accurately estimate their penetrance and establish clinical guidelines in carrier individuals

  20. Multiple start codons and phosphorylation result in discrete Rad52 protein species

    de Mayolo, A.A.; Lisby, M.; Erdeniz, N.;

    2006-01-01

    protein species are due to promiscuous choice of start codons as well as post-translational modification. Specifically, Rad52 is phosphorylated both in a cell cycle-independent and in a cell cycle-dependent manner. Furthermore, phosphorylation is dependent on the presence of the Rad52 C terminus, but not...... dependent on its interaction with Rad51. We also show that the Rad52 protein can be translated from the last three start sites and expression from any one of them is sufficient for spontaneous recombination and the repair of gamma-ray-induced double-strand breaks....

  1. The epistatic relationship between BRCA2 and the other RAD51 mediators in homologous recombination.

    Yong Qing

    2011-07-01

    Full Text Available RAD51 recombinase polymerizes at the site of double-strand breaks (DSBs where it performs DSB repair. The loss of RAD51 causes extensive chromosomal breaks, leading to apoptosis. The polymerization of RAD51 is regulated by a number of RAD51 mediators, such as BRCA1, BRCA2, RAD52, SFR1, SWS1, and the five RAD51 paralogs, including XRCC3. We here show that brca2-null mutant cells were able to proliferate, indicating that RAD51 can perform DSB repair in the absence of BRCA2. We disrupted the BRCA1, RAD52, SFR1, SWS1, and XRCC3 genes in the brca2-null cells. All the resulting double-mutant cells displayed a phenotype that was very similar to that of the brca2-null cells. We suggest that BRCA2 might thus serve as a platform to recruit various RAD51 mediators at the appropriate position at the DNA-damage site.

  2. RadCon: A radiological consequences model. Technical guide - Version 2.0

    A Radiological Consequence model (RadCon) is being developed at ANSTO to assess the radiological consequences, after an incident, in any climate, using appropriate meteorological and radiological transfer parameters. The major areas of interest to the developers are tropical and subtropical climates. This is particularly so given that it is anticipated that nuclear energy will become a mainstay for economies in these regions within the foreseeable future. Therefore, data acquisition and use of parameter values have been concentrated primarily on these climate types. Atmospheric dispersion and deposition for Australia can be modelled and supplied by the Regional Specialised Meteorological Centre (RSMC, one of five in the world) which is part of the Bureau of Meteorology Research Centre (BMRC), Puri et al. (1992). RadCon combines these data (i.e. the time dependent air and ground concentration generated by the dispersion model or measured quantities in the case of an actual incident) with specific regional parameter values to determine the dose to people via the major pathways of external and internal irradiation. For the external irradiation calculations, data are needed on lifestyle information such as the time spent indoors/outdoors, the high/low physical activity rates for different groups of people (especially critical groups) and shielding factors for housing types. For the internal irradiation calculations, data are needed on food consumption, effect of food processing, transfer parameters (soil to plant, plant to animal) and interception values appropriate for the region under study. Where the relevant data are not available default temperate data are currently used. The results of a wide ranging literature search has highlighted where specific research will be initiated to determine the information required for tropical and sub-tropical regions. The user is able to initiate sensitivity analyses within RadCon. This allows the parameters to be ranked in

  3. Characterization of the interaction between the cohesin subunits Rad21 and SA1/2.

    Nenggang Zhang

    Full Text Available The cohesin complex is responsible for the fidelity of chromosomal segregation during mitosis. It consists of four core subunits, namely Rad21/Mcd1/Scc1, Smc1, Smc3, and one of the yeast Scc3 orthologs SA1 or SA2. Sister chromatid cohesion is generated during DNA replication and maintained until the onset of anaphase. Among the many proposed models of the cohesin complex, the 'core' cohesin subunits Smc1, Smc3, and Rad21 are almost universally displayed as tripartite ring. However, other than its supportive role in the cohesin ring, little is known about the fourth core subunit SA1/SA2. To gain deeper insight into the function of SA1/SA2 in the cohesin complex, we have mapped the interactive regions of SA2 and Rad21 in vitro and ex vivo. Whereas SA2 interacts with Rad21 through a broad region (301-750 aa, Rad21 binds to SA proteins through two SA-binding motifs on Rad21, namely N-terminal (NT and middle part (MP SA-binding motif, located at 60-81 aa of the N-terminus and 383-392 aa of the MP of Rad21, respectively. The MP SA-binding motif is a 10 amino acid, α-helical motif. Deletion of these 10 amino acids or mutation of three conserved amino acids (L(385, F(389, and T(390 in this α-helical motif significantly hinders Rad21 from physically interacting with SA1/2. Besides the MP SA-binding motif, the NT SA-binding motif is also important for SA1/2 interaction. Although mutations on both SA-binding motifs disrupt Rad21-SA1/2 interaction, they had no apparent effect on the Smc1-Smc3-Rad21 interaction. However, the Rad21-Rad21 dimerization was reduced by the mutations, indicating potential involvement of the two SA-binding motifs in the formation of the two-ring handcuff for chromosomal cohesion. Furthermore, mutant Rad21 proteins failed to significantly rescue precocious chromosome separation caused by depletion of endogenous Rad21 in mitotic cells, further indicating the physiological significance of the two SA-binding motifs of Rad21.

  4. Biochemical characterization of plant Rad52 protein from rice (Oryza sativa).

    Nair, Anuradha; Agarwal, Rachna; Chittela, Rajani Kant

    2016-09-01

    DNA damage in living cells is repaired by two main pathways, homologous recombination (HR) and non-homologous end joining (NHEJ). Of all the genes promoting HR, Rad52 (Radiation sensitive 52) is an important gene which is found to be highly conserved across different species. It was believed that RAD52 is absent in plant systems until lately. However, recent genetic studies have shown the presence of RAD52 homologues in plants. Rad52 homologues in plant systems have not yet been characterized biochemically. In the current study, we bring out the biochemical properties of rice Rad52-2a protein. OsRad52-2a was over-expressed in Escherichia coli BL21 (DE3) cells and the protein was purified. The identity of purified OsRad52-2a protein was confirmed via peptide mass fingerprinting. Gel filtration and native PAGE analysis indicated that the OsRad52-2a protein in its native state probably formed an undecameric structure. Purified OsRad52-2a protein showed binding to single stranded DNA, double stranded DNA. Protein also mediated the renaturation of complementary single strands into duplex DNA in both agarose gel and FRET based assays. Put together, OsRad52-2a forms oligomeric structures and binds to ssDNA/dsDNA for mediating an important function like renaturation during homologous recombination. This study represents the first report on biochemical properties of OsRad52-2a protein from important crop like rice. This information will help in dissecting the recombination and repair machinery in plant systems. PMID:27156135

  5. A Rad53 Independent Function of Rad9 Becomes Crucial for Genome Maintenance in the Absence of the RecQ Helicase Sgs1

    Nielsen, Ida; Bentsen, Iben Bach; Andersen, Anni Hangaard;

    2013-01-01

    The conserved family of RecQ DNA helicases consists of caretaker tumour suppressors, that defend genome integrity by acting on several pathways of DNA repair that maintain genome stability. In budding yeast, Sgs1 is the sole RecQ helicase and it has been implicated in checkpoint responses......, replisome stability and dissolution of double Holliday junctions during homologous recombination. In this study we investigate a possible genetic interaction between SGS1 and RAD9 in the cellular response to methyl methane sulphonate (MMS) induced damage and compare this with the genetic interaction between...... SGS1 and RAD24. The Rad9 protein, an adaptor for effector kinase activation, plays well-characterized roles in the DNA damage checkpoint response, whereas Rad24 is characterized as a sensor protein also in the DNA damage checkpoint response. Here we unveil novel insights into the cellular response to...

  6. A RAD approach to client/server system development

    The capability, richness, and leverage of inexpensive commercial operating systems, off-the-shelf applications, and powerful developing tools have made building feature-rich client/server systems possible in rapid time and at low cost--ushering in a new level of systems integration not before possible. The authors achieve rapid application development (RAD) by using a flexible and extendible client/service integration framework. The framework provides the means to integrate in-house and third-party software applications with databases and expert-system knowledge bases and, where appropriate, provides communication links among the applications. The authors discuss the integration framework's capabilities, explain its underlying system architecture, and outline the methods and tools used to customize and integrate many diverse applications

  7. Temperature calibration of PICO-RAD detectors for radon measurement

    A simple mathematical equation linking the activity of adsorbed radon in the vials to the time of its exposure has been discussed. The calibration coefficient Ks, defined as a measured activity in cpm after a saturation time, corresponding to a radon air concentration of 1 Bq m-3 has been determined for four temperatures: 284, 291, 294 and 298 K. A linear relationship of ln Ks values versus T-1 has been found. The relatively high difference in Ks values: 2.12 and 1.24 cpm/Bq m3 for the temperatures of 284 and 298 K, respectively, was observed. It indicates that temperature fluctuations during Pico-Rad vial exposure may lead to erroneous results if the constant average temperature of exposure is introduced into a commonly used computer program for calculating Rn concentration. (author). 6 refs, 4 figs

  8. Temperature calibration of Pico-Rad detectors for radon measurement

    A simple mathematical equation linking the activity of adsorbed radon in the vials to the time and temperature of its exposure is discussed. The calibration coefficient - Ks, defined as activity measured in cpm after saturation time, corresponding to radon air concentration of 1 Bq m-3, was determined for four temperatures: 284, 291, 294 and 298 K. A linear relationship of ln Ks values versus T-1 was found. The relatively high difference in Ks values: 2.12 and 1.24 cpm/Bq m-3 for the temperatures of 284 and 298 K, respectively, was observed. It indicates that temperature fluctuations during Pico-Rad vial exposure may lead to erroneous results if the constant average temperature of exposure is introduced into a commonly used computer programme for calculating Rn concentration. (author)

  9. FBH1 helicase disrupts RAD51 filaments in vitro and modulates homologous recombination in mammalian cells

    Simandlova, Jitka; Zagelbaum, Jennifer; Payne, Miranda J;

    2013-01-01

    filaments on DNA through its ssDNA translocase function. Consistent with this, a mutant mouse embryonic stem cell line with a deletion in the FBH1 helicase domain fails to limit RAD51 chromatin association and shows hyper-recombination. Our data are consistent with FBH1 restraining RAD51 DNA binding under...

  10. Rad52 forms DMA repair and recombination centers during S phase

    Lisby, M.; Rothstein, R.; Mortensen, Uffe Hasbro

    2001-01-01

    cerevisiae, homologous recombination is the major pathway for repairing DNA double-strand breaks. The key role played by Rad52 in this pathway has been attributed to its ability to seek out and mediate annealing of homologous DNA strands. In this study, we find that S. cerevisiae Rad52 fused to green...

  11. Enhancement of the RAD51 Recombinase Activity by the Tumor Suppressor PALB2

    Dray, Eloise; Etchin, Julia; Wiese, Claudia; Saro, Dorina; Williams, Gareth J.; Hammel, Michal; Yu, Xiong; Galkin, Vitold E.; Liu, Dongqing; Tsai, Miaw-Sheue; Sy, Shirley M-H.; Egelman, Edward; Chen, Junjie; Sung, Patrick; Schild, D.

    2010-08-24

    Homologous recombination mediated by the RAD51 recombinase helps eliminate chromosomal lesions, such as DNA double-stranded breaks induced by radiation or arising from injured DNA replication forks. The tumor suppressors BRCA2 and PALB2 act together to deliver RAD51 to chromosomal lesions to initiate repair. Here we document a new function of PALB2 in the enhancement of RAD51's ability to form the D-loop. We show that PALB2 binds DNA and physically interacts with RAD51. Importantly, while PALB2 alone stimulates D-loop formation, a cooperative effect is seen with RAD51AP1, an enhancer of RAD51. This stimulation stems from PALB2's ability to function with RAD51 and RAD51AP1 to assemble the synaptic complex. Our results help unveil a multi-faceted role of PALB2 in chromosome damage repair. Since PALB2 mutations can cause breast and other tumors or lead to Fanconi anemia, our findings are important for understanding the mechanism of tumor suppression in humans.

  12. Identification of novel functional domains of Rad52 in Saccharomyces cerevisiae

    Plate, Iben

    2006-01-01

    . cerevisiae er desuden nem at manipulere genetisk og der eksisterer sofistikerede in vivo assays som muliggør visualisering af reparationsprocessen ved hjælp af fluorescensmikroskopi. Rad52 er et vigtigt protein til reparation af DNA DSB i S. cerevisiae og rad52Δ celler har en alvorlig fænotype med langsom...

  13. A novel Rad gene polymorphism combined with obesity increases risk for type 2 diabetes mellitus

    王国英; 牛天华; 陈常忠; 李琼芳; 徐希平

    2004-01-01

    @@ The ras-associated diabetes (Rad) was initially identified by subtraction cloning from the skeletal muscle of humans with non-insulin dependent diabetes mellitus (type 2 DM).1 Rad mRNA expression is markedly increased in the skeletal muscle of type 2 DM patients compared with normal controls.

  14. RAD6 gene of Saccharomyces cerevisiae encodes a protein containing a tract of 13 consecutive aspartates

    The RAD6 gene of Saccharomyces cerevisiae is required for postreplication repair of UV-damaged DNA, for induced mutagenesis, and for sporulation. The authors have mapped the transcripts and determined the nucleotide sequence of the cloned RAD6 gene. The RAD6 gene encodes two transcripts of 0.98 and 0.86 kilobases which differ only in their 3' termini. The transcribed region contains an open reading frame of 516 nucleotides. The rad6-1 and rad6-3 mutant alleles, which the authors have cloned and sequenced, introduce amber and ochre nonsense mutations, respectively into the open reading frame, proving that it encodes the RAD6 protein. The RAD6 protein predicted by the nucleotide sequence is 172 amino acids long, has a molecular weight of 19,704, and contains 23.3% acidic and 11.6% basic residues. Its most striking feature is the highly acidic carboxyl terminus: 20 of the 23 terminal amino acids are acidic, including 13 consecutive aspartates. RAD6 protein thus resembles high mobility group proteins HMG-1 and HMG-2, which each contain a carboxyl-proximal tract of acidic amino acids. 48 references, 6 figures

  15. RadSTAR L-Band Imaging Scatterometer: Performance Assessment

    Rincon, Rafael; Hildebrand, Peter; Hilliard, Larry

    2007-01-01

    RadSTAR is an instrument development program aimed at combining a radiometer and a scatterometer system into a highly compact configuration that uses a single, electronically scanned antenna to provide co-located and simultaneous measurements of emission and backscatter for airborne and spaceborne applications [I]. The program was designed to map soil moisture and ocean salinity, both important components of the water cycle, and to map sea ice density and thickness, an important factor in ocean-atmosphere heat exchange in Polar Regions. The accuracy in estimation of these and a number of other Earth science parameters can be greatly enhanced by providing the co-aligned radar/radiometer microwave measurements. For instance, radiometer estimates of soil moisture from soil emission are affected by emission from vegetation, and from the roughness of the surface. Complementary measurements using the scatterometer can be used to evaluate the vegetation and surface roughness effects. Hence, the combined observations can provide an improved estimate. As with soil moisture, the ocean salinity is a function of the microwave emission from the sea surface temperature (SST) and sea roughness. There, the addition of radar backscatter measurements of sea roughness enables the correction of the emissivity and provide more accurate estimates of ocean salinity. Similar arguments can be made for other important Earth science parameters. This paper discusses the RadSTAR program, the radar system design, calibration, and digital beamforming techniques, and presents preliminary analysis of the data collected during the test flights. The data sets obtained during the flights and during the radar calibration in the anechoic chamber are also employed to asses the performance of the radar. The paper also discusses the Digital Beamforming Synthetic Aperture Radar (DBSAR) processor, a real-time processor recently developed for the LIS instrument which enables beam synthesis, fine resolutions

  16. Aflatoxin B1-Associated DNA Adducts Stall S Phase and Stimulate Rad51 foci in Saccharomyces cerevisiae

    Michael Fasullo

    2010-01-01

    Full Text Available AFB1 is a potent recombinagen in budding yeast. AFB1 exposure induces RAD51 expression and triggers Rad53 activation in yeast cells that express human CYP1A2. It was unknown, however, when and if Rad51 foci appear. Herein, we show that Rad53 activation correlates with cell-cycle delay in yeast and the subsequent formation of Rad51 foci. In contrast to cells exposed to X-rays, in which Rad51 foci appear exclusively in G2 cells, Rad51 foci in AFB1-exposed cells can appear as soon as cells enter S phase. Although rad51 and rad4 mutants are mildly sensitive to AFB1, chronic exposure of the NER deficient rad4 cells to AFB1 leads to increased lag times, while rad4 rad51 double mutants exhibit synergistic sensitivity and do not grow when exposed to 50 μM AFB1. We suggest RAD51 functions to facilitate DNA replication after replication fork stalling or collapse in AFB1-exposed cells.

  17. Rad52 multimerization is important for its nuclear localization in Saccharomyces cerevisiae

    Plate, Iben; Albertsen, Line; Lisby, Michael;

    2008-01-01

    Rad52 is essential for all homologous recombination and DNA double strand break repair events in Saccharomyces cerevisiae. This protein is multifunctional and contains several domains that allow it to interact with DNA as well as with different repair proteins. However, it has been unclear how Ra...... on the results we propose a model where the additive effect of multiple NLS(Rad52) sequences in a Rad52 ring-structure ensures efficient nuclear localization of Rad52.......52 enters the nucleus. In the present study, we have used a combination of mutagenesis and sequence analysis to show that Rad52 from S. cerevisiae contains a single functional pat7 type NLS essential for its nuclear localization. The region containing the NLS seems only to be involved in nuclear...

  18. Comparison of Danish dichotomous and BI-RADS classifications of mammographic density

    Hodge, Rebecca; Hellmann, Sophie Sell; von Euler-Chelpin, My; Vejborg, Ilse; Andersen, Zorana Jovanovic

    2014-01-01

    : Of the 120 women, 32 (26.7%) were classified as having fatty and 88 (73.3%) as mixed/dense mammographic density, according to Danish dichotomous classification. According to BI-RADS density classification, 12 (10.0%) women were classified as having predominantly fatty (BI-RADS code 1), 46 (38.3%) as...... having scattered fibroglandular (BI-RADS code 2), 57 (47.5%) as having heterogeneously dense (BI-RADS 3), and five (4.2%) as having extremely dense (BI-RADS code 4) mammographic density. The inter-rater variability assessed by weighted kappa statistic showed a substantial agreement (0.75). CONCLUSION......BACKGROUND: In the Copenhagen mammography screening program from 1991 to 2001, mammographic density was classified either as fatty or mixed/dense. This dichotomous mammographic density classification system is unique internationally, and has not been validated before. PURPOSE: To compare the Danish...

  19. Breast Imaging Reporting and Data System (BI-RADS) breast composition descriptors: Automated measurement development for full field digital mammography

    Fowler, E. E.; Sellers, T. A.; Lu, B. [Department of Cancer Epidemiology, Division of Population Sciences, H. Lee Moffitt Cancer Center, Tampa, Florida 33612 (United States); Heine, J. J. [Department of Cancer Imaging and Metabolism, H. Lee Moffitt Cancer Center, Tampa, Florida 33612 (United States)

    2013-11-15

    measures were significantly associated with breast cancer status in the adjusted models: (a) OR = 1.95 (1.24, 3.09) for BR{sub pg}; (b) OR = 1.42 (0.87, 2.32) for BR{sub vc}; and (c) OR = 2.13 (1.22, 3.72) for BR{sub vr}. The radiologist-reported measures from the patient records showed a similar association, OR = 1.49 (0.99, 2.24), although only borderline statistically significant.Conclusions: A general framework was developed and validated for converting calibrated mammograms and continuous measures of breast density to fully automated approximations for the BI-RADS breast composition descriptors. The techniques are general and suitable for a broad range of clinical and research applications.

  20. Real-time measurements of the nucleation, growth and dissociation of single Rad51–DNA nucleoprotein filaments

    Miné, Judith; Disseau, Ludovic; Takahashi, Masayuki; Cappello, Giovanni; Dutreix, Marie; Viovy, Jean-Louis

    2007-01-01

    Human Rad51 (hRad51), the protein central to DNA pairing and strand exchange during homologous recombination, polymerizes on DNA to form nucleoprotein filaments. By making use of magnetic tweezers to manipulate individual DNA molecules, we measured the nucleation and growth of hRad51 nucleoprotein filaments, and their subsequent disassembly in real time. The dependence of the initial polymerization rate upon the concentration of hRad51 suggests that the rate-limiting step is the formation of ...

  1. The response of mammalian cells to UV-light reveals Rad54-dependent and independent pathways of homologous recombination

    Eppink, Berina; Tafel, Agnieszka A; Hanada, Katsuhiro;

    2011-01-01

    lesions in replicating DNA. The core HR protein in mammalian cells is the strand exchange protein RAD51, which is aided by numerous proteins, including RAD54. We used RAD54 as a cellular marker for HR to study the response of mammalian embryonic stem (ES) cells to UV irradiation. In contrast to yeast, ES...

  2. Lysine residue 185 of Rad1 is a topological but not a functional counterpart of lysine residue 164 of PCNA.

    Niek Wit

    Full Text Available Monoubiquitylation of the homotrimeric DNA sliding clamp PCNA at lysine residue 164 (PCNA(K164 is a highly conserved, DNA damage-inducible process that is mediated by the E2/E3 complex Rad6/Rad18. This ubiquitylation event recruits translesion synthesis (TLS polymerases capable of replicating across damaged DNA templates. Besides PCNA, the Rad6/Rad18 complex was recently shown in yeast to ubiquitylate also 9-1-1, a heterotrimeric DNA sliding clamp composed of Rad9, Rad1, and Hus1 in a DNA damage-inducible manner. Based on the highly similar crystal structures of PCNA and 9-1-1, K185 of Rad1 (Rad1(K185 was identified as the only topological equivalent of PCNA(K164. To investigate a potential role of posttranslational modifications of Rad1(K185 in DNA damage management, we here generated a mouse model with a conditional deletable Rad1(K185R allele. The Rad1(K185 residue was found to be dispensable for Chk1 activation, DNA damage survival, and class switch recombination of immunoglobulin genes as well as recruitment of TLS polymerases during somatic hypermutation of immunoglobulin genes. Our data indicate that Rad1(K185 is not a functional counterpart of PCNA(K164.

  3. Erythropoietic defect associated with reduced cell proliferation in mice lacking the 26S proteasome shuttling factor Rad23b

    S. Bergink (Steven); A.F. Theil (Arjan); W. Toussaint (Wendy); I.M. de Cuyper (Iris); D.I. Kulu (Divine); T. Clapes (Thomas); R. van der Linden (Reinier); J.A.A. Demmers (Jeroen); E.P. Mul (Eric); F.P. van Alphen (Floris); J.A. Marteijn (Jurgen); T. van Gent (Teus); A. Maas (Alex); C. Robin (Catherine); J.N.J. Philipsen (Sjaak); W. Vermeulen (Wim); J.R. Mitchell (James); L. Gutiérrez (Laura)

    2013-01-01

    textabstractRad23a and Rad23b proteins are linked to nucleotide excision DNA repair (NER) via association with the DNA damage recognition protein xeroderma pigmentosum group C (XPC) are and known to be implicated in protein turnover by the 26S proteasome. Rad23b-null mice are NER proficient, likely

  4. Erythropoietic Defect Associated with Reduced Cell Proliferation in Mice Lacking the 26S Proteasome Shuttling Factor Rad23b

    Bergink, Steven; Theil, Arjan F.; Toussaint, Wendy; De Cuyper, Iris M.; Kulu, Divine I.; Clapes, Thomas; van der Linden, Reinier; Demmers, Jeroen A.; Mul, Eric P.; van Alphen, Floris P.; Marteijn, Jurgen A.; van Gent, Teus; Maas, Alex; Robin, Catherine; Philipsen, Sjaak; Vermeulen, Wim; Mitchell, James R.; Gutierrez, Laura

    2013-01-01

    Rad23a and Rad23b proteins are linked to nucleotide excision DNA repair (NER) via association with the DNA damage recognition protein xeroderma pigmentosum group C (XPC) are and known to be implicated in protein turnover by the 26S proteasome. Rad23b-null mice are NER proficient, likely due to the r

  5. Rad51C deficiency destabilizes XRCC3, impairs recombination and radiosensitizes S/G2-phase cells

    Lio, Yi-Ching; Schild, David; Brenneman, Mark A.; Redpath, J. Leslie; Chen, David J.

    2004-05-01

    The highly conserved Rad51 protein plays an essential role in repairing DNA damage through homologous recombination. In vertebrates, five Rad51 paralogs (Rad51B, Rad51C, Rad51D, XRCC2, XRCC3) are expressed in mitotically growing cells, and are thought to play mediating roles in homologous recombination, though their precise functions remain unclear. Here we report the use of RNA interference to deplete expression of Rad51C protein in human HT1080 and HeLa cells. In HT1080 cells, depletion of Rad51C by small interfering RNA caused a significant reduction of frequency in homologous recombination. The level of XRCC3 protein was also sharply reduced in Rad51C-depleted HeLa cells, suggesting that XRCC3 is dependent for its stability upon heterodimerization with Rad51C. In addition, Rad51C-depleted HeLa cells showed hypersensitivity to the DNA cross-linking agent mitomycin C, and moderately increased sensitivity to ionizing radiation. Importantly, the radiosensitivity of Rad51C-deficient HeLa cells was evident in S and G{sub 2}/M phases of the cell cycle but not in G{sub 1} phase. Together, these results provide direct cellular evidence for the importance of human Rad51C in homologous recombinational repair.

  6. Structure of a hexameric form of RadA recombinase from Methanococcus voltae

    Hexameric rings of RadA recombinase from M. voltae have been crystallized. Structural comparisons suggest that homologues of RadA tend to form double-ringed assemblies. Archaeal RadA proteins are close homologues of eukaryal Rad51 and DMC1 proteins and are remote homologues of bacterial RecA proteins. For the repair of double-stranded breaks in DNA, these recombinases promote a pivotal strand-exchange reaction between homologous single-stranded and double-stranded DNA substrates. This DNA-repair function also plays a key role in the resistance of cancer cells to chemotherapy and radiotherapy and in the resistance of bacterial cells to antibiotics. A hexameric form of a truncated Methanococcus voltae RadA protein devoid of its small N-terminal domain has been crystallized. The RadA hexamers further assemble into two-ringed assemblies. Similar assemblies can be observed in the crystals of Pyrococcus furiosus RadA and Homo sapiens DMC1. In all of these two-ringed assemblies the DNA-interacting L1 region of each protomer points inward towards the centre, creating a highly positively charged locus. The electrostatic characteristics of the central channels can be utilized in the design of novel recombinase inhibitors

  7. Genetic analysis of Escherichia coli RadA: functional motifs and genetic interactions.

    Cooper, Deani L; Boyle, Daniel C; Lovett, Susan T

    2015-03-01

    The RadA/Sms protein is a RecA-related protein found universally in eubacteria and plants, implicated in processing of recombination intermediates. Here we show that the putative Zn finger, Walker A motif, KNRXG motif and Lon protease homology domain of the Escherichia coli RadA protein are required for DNA damage survival. RadA is unlikely to possess protease activity as the putative active site serine is not required. Mutants in RadA have strong synergistic phenotypes with those in the branch migration protein RecG. Sensitivity of radA recG mutants to azidothymidine (AZT) can be rescued by blocking recombination with recA or recF mutations or by overexpression of RuvAB, suggesting that lethal recombination intermediates accumulate in the absence of RadA and RecG. Synthetic genetic interactions for survival to AZT or ciprofloxacin exposure were observed between RadA and known or putative helicases including DinG, Lhr, PriA, Rep, RuvAB, UvrD, YejH and YoaA. These represent the first affected phenotypes reported for Lhr, YejH and YoaA. The specificity of these effects sheds new light on the role of these proteins in DNA damage avoidance and repair and implicates a role in replication gap processing for DinG and YoaA and a role in double-strand break repair for YejH. PMID:25484163

  8. Multiple regulation of Rad51-mediated homologous recombination by fission yeast Fbh1.

    Tsutsui, Yasuhiro; Kurokawa, Yumiko; Ito, Kentaro; Siddique, Md Shahjahan P; Kawano, Yumiko; Yamao, Fumiaki; Iwasaki, Hiroshi

    2014-08-01

    Fbh1, an F-box helicase related to bacterial UvrD, has been proposed to modulate homologous recombination in fission yeast. We provide several lines of evidence for such modulation. Fbh1, but not the related helicases Srs2 and Rqh1, suppressed the formation of crossover recombinants from single HO-induced DNA double-strand breaks. Purified Fbh1 in complex with Skp1 (Fbh1-Skp1 complex) inhibited Rad51-driven DNA strand exchange by disrupting Rad51 nucleoprotein filaments in an ATP-dependent manner; this disruption was alleviated by the Swi5-Sfr1 complex, an auxiliary activator of Rad51. In addition, the reconstituted SCFFbh1 complex, composed of purified Fbh1-Skp1 and Pcu1-Rbx1, displayed ubiquitin-ligase E3 activity toward Rad51. Furthermore, Fbh1 reduced the protein level of Rad51 in stationary phase in an F-box-dependent, but not in a helicase domain-independent manner. These results suggest that Fbh1 negatively regulates Rad51-mediated homologous recombination via its two putative, unrelated activities, namely DNA unwinding/translocation and ubiquitin ligation. In addition to its anti-recombinase activity, we tentatively suggest that Fbh1 might also have a pro-recombination role in vivo, because the Fbh1-Skp1 complex stimulated Rad51-mediated strand exchange in vitro after strand exchange had been initiated. PMID:25165823

  9. Multiple regulation of Rad51-mediated homologous recombination by fission yeast Fbh1.

    Yasuhiro Tsutsui

    2014-08-01

    Full Text Available Fbh1, an F-box helicase related to bacterial UvrD, has been proposed to modulate homologous recombination in fission yeast. We provide several lines of evidence for such modulation. Fbh1, but not the related helicases Srs2 and Rqh1, suppressed the formation of crossover recombinants from single HO-induced DNA double-strand breaks. Purified Fbh1 in complex with Skp1 (Fbh1-Skp1 complex inhibited Rad51-driven DNA strand exchange by disrupting Rad51 nucleoprotein filaments in an ATP-dependent manner; this disruption was alleviated by the Swi5-Sfr1 complex, an auxiliary activator of Rad51. In addition, the reconstituted SCFFbh1 complex, composed of purified Fbh1-Skp1 and Pcu1-Rbx1, displayed ubiquitin-ligase E3 activity toward Rad51. Furthermore, Fbh1 reduced the protein level of Rad51 in stationary phase in an F-box-dependent, but not in a helicase domain-independent manner. These results suggest that Fbh1 negatively regulates Rad51-mediated homologous recombination via its two putative, unrelated activities, namely DNA unwinding/translocation and ubiquitin ligation. In addition to its anti-recombinase activity, we tentatively suggest that Fbh1 might also have a pro-recombination role in vivo, because the Fbh1-Skp1 complex stimulated Rad51-mediated strand exchange in vitro after strand exchange had been initiated.

  10. Breast cancer CADx based on BI-RADS trade mark sign descriptors from two mammographic views

    In this study we compared the performance of computer aided diagnosis (CADx) algorithms based on Breast Imaging Reporting And Data System (BI-RADS trade mark sign ) descriptors from one or two views. To select cases for the study with different mediolateral (MLO) and craniocaudal (CC) view descriptors, we assessed the agreement in BI-RADS trade mark sign lesion descriptors, BI-RADS trade mark sign assessment, and subtlety ratings for 1626 cases from the Digital Database for Screening Mammogrpahy (DDSM) using kappa statistics. We used 115 mass cases with different descriptors for the two views to design linear discriminant analysis (LDA) based CADx algorithms. The CADx algorithms used BI-RADS trade mark sign descriptors and patient age as features. The algorithms based on BI-RADS trade mark sign descriptors from both the views performed marginally better than algorithms based on BI-RADS trade mark sign descriptors from a single view. A system that averaged the results of two classifiers trained separately on the MLO and CC views displayed the best performance (Az=0.920±0.027). Thus, some improvement in performance of BI-RADS trade mark sign based CADx algorithms may be achieved by combining information from two mammographic views

  11. Protective effect of the LevRad on treat of paracoccidioidomycosis

    Paracoccidioides brasiliensis is the agent of Paracoccidioidomycosis (PCM), the most prevalent deep mycosis of Latin America. The period of treat depend on the chemotherapeutic and the severity of disease and its administration not ensure the complete destruction of the fungus. The search for new alternatives is necessary. The aim of this study was to evaluate the protective effect of yeast cells of P. brasiliensis attenuated by gamma irradiation (LevRad) on therapeutic vaccination of BALB/c. The therapeutic potential of LevRad with or without fluconazole was assessed for the first time, intraperitoneally, in BALB/c, 60 days after intratracheal infection with a highly virulent non-irradiated P.brasiliensis isolate. The animals were divided in five experimental groups: uninfected (C-), infected (C+), infected treated with fluconazole (Inmed), infected treated with LevRad (InRad) and infected treated with fluconazole + LevRad (InRadMed). The organs (lungs, spleen and liver) were collected to analyze CFU (colony forming units) and histology. The sera were used to evaluate the immunization efficacy, and to assess IgG subtypes (IgG1, IgG2a, IgG2b, IgG3) and total IgG levels. There was significant decrease in the CFU counts of the lungs of InMed, InRadMed and InRad. No were visualized histopathological alterations in the organs of these groups, except in InRad there was granulomatous lesions unifocal, little and discrete. The levels of IgG and its subtypes IgG2a, IgG2b increased, probably due to the increase of cytokines that promote switching to these isotypes. These preliminary results can provide new prospect for immunotherapy of PCM, but it will be necessary new studies to evaluate administration dose and period treatment. (author)

  12. Rad21-cohesin haploinsufficiency impedes DNA repair and enhances gastrointestinal radiosensitivity in mice.

    Huiling Xu

    Full Text Available Approximately half of cancer-affected patients receive radiotherapy (RT. The doses delivered have been determined upon empirical experience based upon average radiation responses. Ideally higher curative radiation doses might be employed in patients with genuinely normal radiation responses and importantly radiation hypersensitive patients would be spared the consequences of excessive tissue damage if they were identified before treatment. Rad21 is an integral subunit of the cohesin complex, which regulates chromosome segregation and DNA damage responses in eukaryotes. We show here, by targeted inactivation of this key cohesin component in mice, that Rad21 is a DNA-damage response gene that markedly affects animal and cell survival. Biallelic deletion of Rad21 results in early embryonic death. Rad21 heterozygous mutant cells are defective in homologous recombination (HR-mediated gene targeting and sister chromatid exchanges. Rad21+/- animals exhibited sensitivity considerably greater than control littermates when challenged with whole body irradiation (WBI. Importantly, Rad21+/- animals are significantly more sensitive to WBI than Atm heterozygous mutant mice. Since supralethal WBI of mammals most typically leads to death via damage to the gastrointestinal tract (GIT or the haematopoietic system, we determined the functional status of these organs in the irradiated animals. We found evidence for GIT hypersensitivity of the Rad21 mutants and impaired bone marrow stem cell clonogenic regeneration. These data indicate that Rad21 gene dosage is critical for the ionising radiation (IR response. Rad21 mutant mice thus represent a new mammalian model for understanding the molecular basis of irradiation effects on normal tissues and have important implications in the understanding of acute radiation toxicity in normal tissues.

  13. Investigation of the influence of high humidity and exposure duration on the measurement results of radon concentration by means of PicoRad system in the CLOR calibration chamber

    PicoRad system based on activated charcoal collectors and liquid scintillation counter is one of the most popular passive methods of radon measurements which may be used both indoors and in other environments such as caves, tunnels, mines etc. It is well known that charcoal is also a very good adsorber of water vapor and it can reduce adsorption efficiency for radon. In PicoRad collectors, the charcoal is mixed with a dessicant to lower this effect. A series of expositions of PicoRad detectors was performed in a Central Laboratory for Radiological Protection (CLOR) radon calibration/climatic chamber to study the effect of high relative humidity on the airborne radon concentration measurements and the dependence of the results on the duration of exposure. The results obtained from the PicoRad system were referred to the mean concentrations delivered by an AlphaGUARD monitor, Genitron (GmbH), Germany. The main conclusions are the following: 1) the PicoRad system results are not affected by high relative humidity, including extreme values of 90-96%, for the duration of exposure up to ca. 24 h; 2) in the relative humidity range of 75-96% the correction coefficient linearly depends on the duration of exposure reaching a value of ca. 16 for 96 h exposure; 3) the PicoRad system delivers results corresponding better to the mean value of radon concentration in the last 6 h interval of exposure than that in the whole exposure duration. This finding is particularly important for the calibration of PicoRad collectors in the conditions of decreasing radon concentration due to radon decay. (author)

  14. Conduction electron spin resonance in the α-Yb1−xFexAlB4 (0 ⩽ x ⩽ 0.50) and α-LuAlB4 compounds

    β-YbAlB4 has become one of the most studied heavy fermion systems since its discovery due to its remarkable physical properties. This system is the first reported Yb-based heavy-fermion superconductor (HFS) for which the low-T superconducting state emerges from a non-fermi-liquid (NFL) normal state associated with quantum criticality Nakatsuji et al 2008 Nature 4 603. Additionally, it presents a striking and unprecedented electron spin resonance (ESR) signal which behaves as a conduction electron spin resonance (CESR) at high temperatures and acquires features of the Yb3+ local moment ESR at low temperatures. The latter, also named Kondo quasiparticles spin resonance (KQSR), has been defined as a 4f-ce strongly coupled ESR mode that behaves as a local probe of the Kondo quasiparticles in a quantum critical regime, Holanda et al 2011 Phys. Rev. Lett. 107 026402. Interestingly, β-YbAlB4 possesses a previously known structural variant, namely the α-YbAlB4, phase which is a paramagnetic Fermi liquid (FL) at low temperatures Macaluso et al 2007 Chem. Mater. 19 1918. However, it has been recently suggested that the α-YbAlB4 phase may be tuned to NFL behavior and/or magnetic ordering as the compound is doped with Fe. Here we report ESR studies on the α-Yb1−xFexAlB4 (0 ⩽ x ⩽ 0.50) series as well as on the reference compound α-LuAlB4. For all measured samples, the observed ESR signal behaves as a CESR in the entire temperature range (10 K ≲ T ≲ 300 K) in clear contrast with what has been observed for β-YbAlB4. This striking result indicates that the proximity to a quantum critical point is crucial to the occurrence of a KQSR signal. (paper)

  15. The role of RAD51 in etoposide (VP16) resistance in small cell lung cancer

    Hansen, Lasse Tengbjerg; Lundin, Cecilia; Spang-Thomsen, Mogens;

    2003-01-01

    investigated DSB repair and cellular VP16 sensitivity of SCLC cells. VP16 sensitivity and RAD51, DNA-PK(cs), topoisomerase IIalpha and P-glycoprotein protein levels were determined in 17 SCLC cell lines. In order to unravel the role of RAD51 in VP16 resistance, we cloned the human RAD51 gene, transfected SCLC......Etoposide (VP16) is a potent inducer of DNA double-strand breaks (DSBs) and is efficiently used in small cell lung cancer (SCLC) therapy. However, acquired VP16 resistance remains an important barrier to effective treatment. To understand the underlying mechanisms for VP16 resistance in SCLC, we...

  16. Evidence for linear response for the induction of mutations in human cells by x-ray exposures below 10 rads.

    Grosovsky, A J; Little, J B

    1985-01-01

    The induction of 6-thioguanine resistance (6TGR) was studied in continuous human lymphoblast cultures exposed to daily x-ray doses of 1, 2.5, 5, or 10 rads (1 rad = 0.01 gray) for periods up to 1 month. Samples were taken every 5 days for determinations of induced mutation frequency. Cells receiving daily doses of 1-10 rads showed a mutation frequency of 0.069 X 10(-6) 6TGR cell per rad, virtually identical to the value of 0.062 X 10(-6) 6TGR cell per rad determined for lymphoblasts receiving...

  17. Breast imaging reporting and data system (BI-RADS) lexicon for breast MRI: Interobserver variability in the description and assignment of BI-RADS category

    El Khoury, Mona, E-mail: monelkhoury@gmail.com [Centre Hospitalier Universitaire de Montréal, Breast Centre, Radiology Department, 3840 Rue Saint Urbain, Montréal, QC H2W1T8 (Canada); Lalonde, Lucie; David, Julie; Labelle, Maude [Centre Hospitalier Universitaire de Montréal, Breast Centre, Radiology Department, 3840 Rue Saint Urbain, Montréal, QC H2W1T8 (Canada); Mesurolle, Benoit [Centre Hospitalier Universitaire de McGill, Cedar Breast Centre, Radiology Department, 687 Pine Avenue West, Montreal, QC H3A1A1 (Canada); Trop, Isabelle [Centre Hospitalier Universitaire de Montréal, Breast Centre, Radiology Department, 3840 Rue Saint Urbain, Montréal, QC H2W1T8 (Canada)

    2015-01-15

    Highlights: • The use of BI-RADS lexicon in interpreting breast MRI examinations is beneficial. • Our study shows: (a) moderate to substantial agreement between observers and (b) better agreement in interpreting mass than non-mass enhancement (NME). • Careful analysis of the NME should be done to help detect cancer as early as possible. - Abstract: Purpose: To retrospectively evaluate interobserver variability between breast radiologists when describing abnormal enhancement on breast MR examinations and assigning a BI-RADS category using the Breast Imaging Reporting and Data System (BI-RADS) terminology. Materials and methods: Five breast radiologists blinded to patients’ medical history and pathologic results retrospectively and independently reviewed 257 abnormal areas of enhancement on breast MRI performed in 173 women. Each radiologist described the focal enhancement using BI-RADS terminology and assigned a final BI-RADS category. Krippendorff's α coefficient of agreement was used to asses interobserver variability. Results: All radiologists agreed on the morphology of enhancement in 183/257 (71%) lesions, yielding a substantial agreement (Krippendorff's α = 0.71). Moderate agreement was obtained for mass descriptors – shape, margins and internal enhancement – (α = 0.55, 0.51 and 0.45 respectively) and NME (non-mass enhancement) descriptors – distribution and internal enhancement – (α = 0.54 and 0.43). Overall substantial agreement was obtained for BI-RADS category assignment (α = 0.71). It was however only moderate (α = 0.38) for NME compared to mass (α = 0.80). Conclusion: Our study shows good agreement in describing mass and NME on a breast MR examination but a better agreement in predicting malignancy for mass than NME.

  18. Complementary Roles of Yeast Rad4p and Rad34p in Nucleotide Excision Repair of Active and Inactive rRNA Gene Chromatin▿

    Tremblay, Maxime; Teng, Yumin; Paquette, Michel; Waters, Raymond; Conconi, Antonio

    2008-01-01

    Nucleotide excision repair (NER) removes a plethora of DNA lesions. It is performed by a large multisubunit protein complex that finds and repairs damaged DNA in different chromatin contexts and nuclear domains. The nucleolus is the most transcriptionally active domain, and in yeast, transcription-coupled NER occurs in RNA polymerase I-transcribed genes (rDNA). Here we have analyzed the roles of two members of the xeroderma pigmentosum group C family of proteins, Rad4p and Rad34p, during NER ...

  19. Rad-hard Location and Attitude Module (R-LAM) Project

    National Aeronautics and Space Administration — R-LAM (Rad-hard Location and Attitude Module), promises a new generation of both integrated navigation modules and stand-alone navigation subsystems including...

  20. Wide Temperature Rad-Hard ASIC for Process Control of a Fuel Cell System Project

    National Aeronautics and Space Administration — Ridgetop Group developed a top-level design of a rad-hard application-specific integrated circuit (ASIC) for spacecraft power management that is functional over a...

  1. Sol-Rad Net Flux (L 1.0, 1.5, 2.0)

    National Aeronautics and Space Administration — SolRad-Net (Solar Radiation Network) is an established network of ground-based sensors providing high-frequency solar flux measurements in quasi-realtime to the...

  2. RadNet Map Interface for Near-Real-Time Radiation Monitoring Data

    U.S. Environmental Protection Agency — RadNet is a national network of monitoring stations that regularly collect air, precipitation, drinking water, and milk samples for analysis of radioactivity. The...

  3. Mammography, pathology and BI-RADS categorization in breast ductal carcinoma in situ

    Objective: To explore the mammographic features and value of breast imaging reporting and data system (BI-RADS) in ductal carcinoma-in-situ (DCIS). Methods: The mammography, positive predictive value of BI-RADS categorization, and pathology of DCIS in 30 patients were retrospectively analyzed. Results: Microcalcification was the dominant feature in DCIS and was sand-like, branching or pleomorphic (14 cases). Other features included mass (3) and architectural distortion (2). Mammography was normal in 11 patients. BI-RADS categories were 0 (8 cases), 2 (2 cases), 3 (2 cases), 4 (9 cases) and 5 (9 cases) with positive predictive value of 60.0%. Conclusion: The dominant mammogram feature of DCIS is microcalcification. The positive predictive value of BI-RADS categorization is low and should be complemented by other investigations. (authors)

  4. Variations of dose rate observed by MSL/RAD in transit to Mars

    Guo, Jingnan; Wimmer-Schweingruber, Robert F; Hassler, Donald M; Posner, Arik; Heber, Bernd; Köhler, Jan; Rafkin, Scot; Ehresmann, Bent; Appel, Jan K; Böhm, Eckart; Böttcher, Stephan; Burmeister, Sönke; Brinza, David E; Lohf, Henning; Martin, Cesar; Reitz, Günther

    2015-01-01

    Aims: To predict the cruise radiation environment related to future human missions to Mars, the correlation between solar modulation potential and the dose rate measured by the Radiation Assessment Detector (RAD) has been analyzed and empirical models have been employed to quantify this correlation. Methods: The instrument RAD, onboard Mars Science Laboratory's (MSL) rover Curiosity, measures a broad spectrum of energetic particles along with the radiation dose rate during the 253-day cruise phase as well as on the surface of Mars. With these first ever measurements inside a spacecraft from Earth to Mars, RAD observed the impulsive enhancement of dose rate during solar particle events as well as a gradual evolution of the galactic cosmic ray (GCR) induced radiation dose rate due to the modulation of the primary GCR flux by the solar magnetic field, which correlates with long-term solar activities and heliospheric rotation. Results: We analyzed the dependence of the dose rate measured by RAD on solar modulatio...

  5. Contribution à l'étude structurale par PY/CG-SM de la matière organique liée aux particules fines (0-50 µm dans quelques sols sous formations naturelles de longue durée au Burkina Faso

    Pallo, FJP.

    2011-01-01

    Full Text Available Contribution to the study by PY/GC-MS of organic matter linked to fine particles (0-50 µm in some soils under long-term natural formations in Burkina Faso. The study aims to enhance the knowledge on organic matter of Arenosols, Ferralsols, and Cambisols in Burkina Faso. It deals with the distribution of C and N in three particles size fractions and is focused on the structures of organic matter linked to the (0-50 µm fraction. The results showed that total organic matter was lower than 2% in all soil units. More than 70% of total carbon were held by the finest fraction. The main products released by PY/GC-MS technique of the (0-50 µm fraction were lignin derived compounds, non lignin derived aromatic compounds, carbohydrates derived compounds, fatty acids methyl esters and nitrogen derived compounds. The aliphatic compounds ranged from C12 to C18, C16 being the dominant one. The aliphatic compounds were negatively correlated with the aromatic compounds. A positive correlation was observed between the nitrogen derived compounds and the amounts of clay. On the other hand, the carbohydrates derived compounds were negatively correlated with clay particles. Furthermore, the study pointed out some different structures of lignin such as syringyl, guaiacyl, and p.hydrophenyl. Depending on the nature of wood (hard wood, soft wood and grasses, they reflected the composition of vegetation on the studied sites. Therefore, PY/GC-MS technique was efficient for structural characterization of low amounts of soil organic matter.

  6. RadOnc: An Integrated Clinical Database and Information Retrieval System Implemented by HyperCard

    Michael, Patricia A.; Foxlee, R. Heath

    1989-01-01

    RadOnc is a prototype hypermedia program designed for the resident physician which integrates a radiation oncology clinical database with reference information. Basic and clinical science information relevant to radiation oncology with pertinent literature reviews are linked to patient records which contain a clinical summary of the presentation, treatment and results. RadOnc's features include a dictionary, search capability, navigational aids, information printing and archiving, and graphic...

  7. Sudden Telomere Lengthening Triggers a Rad53-dependent Checkpoint in Saccharomyces cerevisiae

    Viscardi, Valeria; Baroni, Enrico; Romano, Michele; Lucchini, Giovanna; Longhese, Maria Pia

    2003-01-01

    Telomeres are specialized functional complexes that ensure chromosome stability by protecting chromosome ends from fusions and degradation and avoiding chromosomal termini from being sensed as DNA breaks. Budding yeast Tel1 is required both for telomere metabolism and for a Rad53-dependent checkpoint responding to unprocessed double-strand breaks. We show that overexpression of a GAL1-TEL1 fusion causes transient telomere lengthening and activation of a Rad53-dependent...

  8. Multiple Rad5 activities mediate sister chromatid recombination to bypass DNA damage at stalled replication forks

    Minca, Eugen C; Kowalski, David

    2010-01-01

    DNA damage that blocks replication is bypassed in order to complete chromosome duplication and preserve cell viability and genome stability. Rad5, a PCNA polyubiquitin ligase and DNA-dependent ATPase in yeast, is orthologous to putative tumor suppressors and controls error-free damage bypass by an unknown mechanism. To identify the mechanism in vivo, we investigated the roles of Rad5 and analyzed the DNA structures that form during damage bypass at site-specific stalled forks present at repli...

  9. The checkpoint Saccharomyces cerevisiae Rad9 protein contains a tandem tudor domain that recognizes DNA.

    Lancelot, Nathalie; Charier, Gaëlle; Couprie, Joël; Duband-Goulet, Isabelle; Alpha-Bazin, Béatrice; Quémeneur, Eric; Ma, Emilie; Marsolier-Kergoat, Marie-Claude; Ropars, Virginie; Charbonnier, Jean-Baptiste; Miron, Simona; Craescu, Constantin,; Callebaut, Isabelle; Gilquin, Bernard; Zinn-Justin, Sophie

    2007-01-01

    DNA damage checkpoints are signal transduction pathways that are activated after genotoxic insults to protect genomic integrity. At the site of DNA damage, 'mediator' proteins are in charge of recruiting 'signal transducers' to molecules 'sensing' the damage. Budding yeast Rad9, fission yeast Crb2 and metazoan 53BP1 are presented as mediators involved in the activation of checkpoint kinases. Here we show that, despite low sequence conservation, Rad9 exhibits a tandem tudor domain structurally...

  10. RadBall™ Technology Testing and MCNP Modeling of the Tungsten Collimator

    Farfán, Eduardo B.; Foley, Trevor Q.; Coleman, J. Rusty; Jannik, G. Timothy; Holmes, Christopher J.; Oldham, Mark; Adamovics, John; Stanley, Steven J.

    2010-01-01

    The United Kingdom’s National Nuclear Laboratory (NNL) has developed a remote, non-electrical, radiation-mapping device known as RadBall™, which can locate and quantify radioactive hazards within contaminated areas of the nuclear industry. RadBall™ consists of a colander-like outer shell that houses a radiation-sensitive polymer sphere. The outer shell works to collimate radiation sources and those areas of the polymer sphere that are exposed react, becoming increasingly more opaque, in propo...

  11. Chemogenetic profiling identifies RAD17 as synthetically lethal with checkpoint kinase inhibition.

    Shen, John Paul; Srivas, Rohith; Gross, Andrew; Li, Jianfeng; Jaehnig, Eric J; Sun, Su Ming; Bojorquez-Gomez, Ana; Licon, Katherine; Sivaganesh, Vignesh; Xu, Jia L; Klepper, Kristin; Yeerna, Huwate; Pekin, Daniel; Qiu, Chu Ping; van Attikum, Haico; Sobol, Robert W; Ideker, Trey

    2015-11-01

    Chemical inhibitors of the checkpoint kinases have shown promise in the treatment of cancer, yet their clinical utility may be limited by a lack of molecular biomarkers to identify specific patients most likely to respond to therapy. To this end, we screened 112 known tumor suppressor genes for synthetic lethal interactions with inhibitors of the CHEK1 and CHEK2 checkpoint kinases. We identified eight interactions, including the Replication Factor C (RFC)-related protein RAD17. Clonogenic assays in RAD17 knockdown cell lines identified a substantial shift in sensitivity to checkpoint kinase inhibition (3.5-fold) as compared to RAD17 wild-type. Additional evidence for this interaction was found in a large-scale functional shRNA screen of over 100 genotyped cancer cell lines, in which CHEK1/2 mutant cell lines were unexpectedly sensitive to RAD17 knockdown. This interaction was widely conserved, as we found that RAD17 interacts strongly with checkpoint kinases in the budding yeast Saccharomyces cerevisiae. In the setting of RAD17 knockdown, CHEK1/2 inhibition was found to be synergistic with inhibition of WEE1, another pharmacologically relevant checkpoint kinase. Accumulation of the DNA damage marker γH2AX following chemical inhibition or transient knockdown of CHEK1, CHEK2 or WEE1 was magnified by knockdown of RAD17. Taken together, our data suggest that CHEK1 or WEE1 inhibitors are likely to have greater clinical efficacy in tumors with RAD17 loss-of-function. PMID:26437225

  12. Amelioration of radiation-induced hematopoietic and gastrointestinal damage by Ex-RAD in mice

    The aim of the present study was to assess recovery from hematopoietic and gastrointestinal damage by Ex-RAD, also known as ON01210.Na (4-carboxystyryl-4-chlorobenzylsulfone, sodium salt), after total body radiation. In our previous study, we reported that Ex-RAD, a small-molecule radioprotectant, enhances survival of mice exposed to gamma radiation, and prevents radiation-induced apoptosis as measured by the inhibition of radiation-induced protein 53 (p53) expression in cultured cells. We have expanded this study to determine best effective dose, dose-reduction factor (DRF), hematological and gastrointestinal protection, and in vivo inhibition of p53 signaling. A total of 500 mg/kg of Ex-RAD administered at 24 h and 15 min before radiation resulted in a DRF of 1.16. Ex-RAD ameliorated radiation-induced hematopoietic damage as monitored by the accelerated recovery of peripheral blood cells, and protection of granulocyte macrophage colony-forming units (GM-CFU) in bone marrow. Western blot analysis on spleen indicated that Ex-RAD treatment inhibited p53 phosphorylation. Ex-RAD treatment reduces terminal deoxynucleotidyl transferase mediated dUTP nick end labeling assay (TUNEL)-positive cells in jejunum compared with vehicle-treated mice after radiation injury. Finally, Ex-RAD preserved intestinal crypt cells compared with the vehicle control at 13 and 14 Gy. The results demonstrated that Ex-RAD ameliorates radiation-induced peripheral blood cell depletion, promotes bone marrow recovery, reduces p53 signaling in spleen and protects intestine from radiation injury. (author)

  13. Breast imaging reporting and data system (BI-RADS) US lexicon and final assessment category for solid breast masses: the rates of inter-and intraobserver agreement

    To evaluate the rates of inter-and intraobserver agreement of the BI-RADS US lexicon. Two radiologists reviewed 60 sonograms of solid breast masses to evaluate interobserver agreement. After four weeks, the radiologists reinterpreted the series to evaluate the intraobserver agreement. The radiologists described shape, orientation, margin, lesion boundary, echo pattern, posterior acoustic features and microcalcifications. Final assessment categories and management plans were suggested for each case. The rates of inter-and intraobserver agreements were measured by the use of kappa statistics. Interobserver agreement ranged from the highest for orientation (κ = 0.65) and shape (κ = 0.61) to the lowest for posterior acoustic features (κ = 0.42). For the final assessment categories (κ = 0.46) and management (κ = 0.49), interobserver agreement were moderate. Intraobserver agreement ranged from the highest for microcalcifications in mass (κ = 0.90, 0.82) and orientation (κ 0.87, 0.83) and the lowest for echo patterns (κ = 0.62, 0.57) and posterior acoustic features (κ = 0.59, 0.65). In the final assessment category and management, intraobserver agreements were substantial or nearly complete (κ = 0.65-0.83). There were variable raged inter-and intraobserver agreements in the description of the BI-RADS US lexicon of solid breast masses. Among them, margin and lesion boundary showed lower agreements. A modification of the BI-RADS US lexicon with more detailed guidelines, followed by continuous education, are suggested

  14. BI-RADS CATEGORIZATION AND POSITIVE PREDICTIVE VALUE OF MAMMOGRAPHIC FEATURES

    2001-01-01

    Objective: To determine whether the categories defined in the Breast Imaging Reporting and Data System (BI-RADS) are useful predictors of malignancy. Methods: A total of 348 cases with benign and malignant breast diseases were collected. Mammographic and pathologic findings were reviewed. Mammograms of 348 cases were characterized according to BI-RADS descriptors and were categorized by the final assessment categories. Results: Of the all 348 patients, 232 (67%) were carcinomas. Significantly more masses with calcification and speculation were found in breast cancers than in benign breast diseases. BI-RADS final assessment categories were category 2 and 3 in 106 cases, in which 75% (79/106) were benign; category 4 and 5 in 242 cases, in which 85% (205/242) were carcinomas. BI-RADS categories 4 and 5 are useful predictors of relative likelihood of malignancy. The features with higher positive predictive values for carcinomas were irregular shape, indistinct or speculated margins, fine or linear calcification morphology, and regional calcification distribution. Conclusion: BI-RADS lexicon is successful in providing a standardized language for physicians to describe lesion morphology. BI-RADS category is useful for predicting the presence of malignancy.

  15. High-throughput polymorphism detection and genotyping in Brassica napus using next-generation RAD sequencing

    Bus Anja

    2012-06-01

    Full Text Available Abstract Background The complex genome of rapeseed (Brassica napus is not well understood despite the economic importance of the species. Good knowledge of sequence variation is needed for genetics approaches and breeding purposes. We used a diversity set of B. napus representing eight different germplasm types to sequence genome-wide distributed restriction-site associated DNA (RAD fragments for polymorphism detection and genotyping. Results More than 113,000 RAD clusters with more than 20,000 single nucleotide polymorphisms (SNPs and 125 insertions/deletions were detected and characterized. About one third of the RAD clusters and polymorphisms mapped to the Brassica rapa reference sequence. An even distribution of RAD clusters and polymorphisms was observed across the B. rapa chromosomes, which suggests that there might be an equal distribution over the Brassica oleracea chromosomes, too. The representation of Gene Ontology (GO terms for unigenes with RAD clusters and polymorphisms revealed no signature of selection with respect to the distribution of polymorphisms within genes belonging to a specific GO category. Conclusions Considering the decreasing costs for next-generation sequencing, the results of our study suggest that RAD sequencing is not only a simple and cost-effective method for high-density polymorphism detection but also an alternative to SNP genotyping from transcriptome sequencing or SNP arrays, even for species with complex genomes such as B. napus.

  16. Overexpressed of RAD51 suppresses recombination defects: a possible mechanism to reverse genomic instability

    Schild, David; Wiese, Claudia

    2009-10-15

    RAD51, a key protein in the homologous recombinational DNA repair (HRR) pathway, is the major strand-transferase required for mitotic recombination. An important early step in HRR is the formation of single-stranded DNA (ss-DNA) coated by RPA (a ss-DNA binding protein). Displacement of RPA by RAD51 is highly regulated and facilitated by a number of different proteins known as the 'recombination mediators'. To assist these recombination mediators, a second group of proteins also is required and we are defining these proteins here as 'recombination co-mediators'. Defects in either recombination mediators or comediators, including BRCA1 and BRCA2, lead to impaired HRR that can genetically be complemented for (i.e. suppressed) by overexpression of RAD51. Defects in HRR have long been known to contribute to genomic instability leading to tumor development. Since genomic instability also slows cell growth, precancerous cells presumably require genomic restabilization to gain a growth advantage. RAD51 is overexpressed in many tumors, and therefore, we hypothesize that the complementing ability of elevated levels of RAD51 in tumors with initial HRR defects limits genomic instability during carcinogenic progression. Of particular interest, this model may also help explain the high frequency of TP53 mutations in human cancers, since wild-type p53 represses RAD51.

  17. RadCon: A radiological consequence assessment model for environmental protection

    This paper highlights the development of a radiological consequences model (RadCon) for use in the Australian and South East Asian Region, the acquisition of available data for use with the model, and sensitivity analysis ability to target future research. RadCon is a simple easy to use model that assesses the radiological dose consequences to humans resulting from the short-term release of radionuclides to the environment and in the process provides the concentrations of the chosen radionuclides in the selected plants and animals. This way, environmental protection can be addressed. Internal and external exposures from the passing cloud and from radionuclides deposited on the ground can be assessed in humans, and given the required data also in animals. RadCon does not provide atmospheric dispersion and ground deposition estimates and requires input data from meteorological models or measured data. RadCon was tested in an international model inter-comparison program (BIOMASS) sponsored by the International Atomic Energy Agency and performed well. The model continued to evolve over the period of the exercise and the final estimates generated by RadCon were comparable to the test data. From this BIOMASS experience, a module has been added to RadCon to allow the viewing of concentrations of radionuclides in plant and animal products together with the generation of a 95% confidence interval for the estimates. (author)

  18. Rad18 is required for functional interactions between FANCD2, BRCA2, and Rad51 to repair DNA topoisomerase 1-poisons induced lesions and promote fork recovery

    Tripathi, Kaushlendra; Mani, Chinnadurai; Clark, David W; Palle, Komaraiah

    2016-01-01

    Camptothecin (CPT) and its analogues are chemotherapeutic agents that covalently and reversibly link DNA Topoisomerase I to its nicked DNA intermediate eliciting the formation of DNA double strand breaks (DSB) during replication. The repair of these DSB involves multiple DNA damage response and repair proteins. Here we demonstrate that CPT-induced DNA damage promotes functional interactions between BRCA2, FANCD2, Rad18, and Rad51 to repair the replication-associated DSB through homologous recombination (HR). Loss of any of these proteins leads to equal disruption of HR repair, causes chromosomal aberrations and sensitizes cells to CPT. Rad18 appears to function upstream in this repair pathway as its downregulation prevents activation of FANCD2, diminishes BRCA2 and Rad51 protein levels, formation of nuclear foci of all three proteins and recovery of stalled or collapsed replication forks in response to CPT. Taken together this work further elucidates the complex interplay of DNA repair proteins in the repair of replication-associated DSB. PMID:26871286

  19. Overexpression of Rad in muscle worsens diet-induced insulin resistance and glucose intolerance and lowers plasma triglyceride level

    Ilany, Jacob; Bilan, Philip J.; Kapur, Sonia; Caldwell, James S.; Patti, Mary-Elizabeth; Marette, Andre; Kahn, C. Ronald

    2006-03-01

    Rad is a low molecular weight GTPase that is overexpressed in skeletal muscle of some patients with type 2 diabetes mellitus and/or obesity. Overexpression of Rad in adipocytes and muscle cells in culture results in diminished insulin-stimulated glucose uptake. To further elucidate the potential role of Rad in vivo, we have generated transgenic (tg) mice that overexpress Rad in muscle using the muscle creatine kinase (MCK) promoter-enhancer. Rad tg mice have a 6- to 12-fold increase in Rad expression in muscle as compared to wild-type littermates. Rad tg mice grow normally and have normal glucose tolerance and insulin sensitivity, but have reduced plasma triglyceride levels. On a high-fat diet, Rad tg mice develop more severe glucose intolerance than the wild-type mice; this is due to increased insulin resistance in muscle, as exemplified by a rightward shift in the dose-response curve for insulin stimulated 2-deoxyglucose uptake. There is also a unexpected further reduction of the plasma triglyceride levels that is associated with increased levels of lipoprotein lipase in the Rad tg mice. These results demonstrate a potential synergistic interaction between increased expression of Rad and high-fat diet in creation of insulin resistance and altered lipid metabolism present in type 2 diabetes. diabetes mellitus | glucose transport | RGK GTPase | transgenic mouse

  20. Extending RAD tag analysis to microbial ecology: a comparison between MultiLocus Sequence Typing and 2b-RAD to investigate Listeria monocytogenes genetic structure.

    Pauletto, Marianna; Carraro, Lisa; Babbucci, Massimiliano; Lucchini, Rosaria; Bargelloni, Luca; Cardazzo, Barbara

    2016-05-01

    The advent of next-generation sequencing (NGS) has dramatically changed bacterial typing technologies, increasing our ability to differentiate bacterial isolates. Despite it is now possible to sequence a bacterial genome in a few days and at reasonable costs, most genetic analyses do not require whole-genome sequencing, which also remains impractical for large population samples due to the cost of individual library preparation and bioinformatics. More traditional sequencing approaches, however, such as MultiLocus Sequence Typing (mlst) are quite laborious and time-consuming, especially for large-scale analyses. In this study, a genotyping approach based on restriction site-associated (RAD) tag sequencing, 2b-RAD, was applied to characterize Listeria monocytogenes strains. To verify the feasibility of the method, an in silico analysis was performed on 30 available complete genomes. For the same set of strains, in silico mlst analysis was conducted as well. Subsequently, 2b-RAD and mlst analyses were experimentally carried out on 58 isolates collected from food samples or food-processing sites. The obtained results demonstrate that 2b-RAD predicts mlst types and often provides more detailed information on population structure than mlst. Moreover, the majority of variants differentiating identical sequence type isolates mapped against accessory fragments, thus providing additional information to characterize strains. Although mlst still represents a reliable typing method, large-scale studies on molecular epidemiology and public health, as well as bacterial phylogenetics, population genetics and biosafety could benefit of a low cost and fast turnaround time approach such as the 2b-RAD analysis proposed here. PMID:26613186

  1. Neocarzinostatin-induced Rad51 nuclear focus formation is cell cycle regulated and aberrant in AT cells

    DNA double-stranded breaks are the most detrimental form of DNA damage and, if not repaired properly, may lead to an accumulation of chromosomal aberrations and eventually tumorigenesis. Proteins of the Rad51/Rad52 epitasis group are crucial for the recombinational repair of DNA double-stranded breaks, whereas the Rad50/NBS1/Mre11 nuclease complex is involved in both the recombinational and the end-joining repair of DNA double-stranded breaks. Herein, we demonstrate that the chemotherapeutic enediyne antibiotic neocarzinostatin induced Rad51, but not NBS1, nuclear focus formation in a cell- cycle-dependent manner. Furthermore, neocarzinostatin-induced Rad51 foci formation revealed a slower kinetic change in AT cells, but not in wild-type or NBS cells. In summary, our results suggest that neocarzinostatin induces Rad51 focus formation through an ATM- and cell-cycle-dependent, but NBS1-independent, pathway

  2. Yeast Rad5 Protein Required for Postreplication Repair Has a DNA Helicase Activity Specific for Replication Fork Regression

    Blastyák, András; Pintér, Lajos; Unk, Ildiko; Prakash, Louise; Prakash, Satya; Haracska, Lajos

    2007-01-01

    Summary Lesions in the template DNA strand block the progression of the replication fork. In the yeast Saccharomyces cerevisiae, replication through DNA lesions is mediated by different Rad6-Rad18-dependent means, which include translesion synthesis and a Rad5-dependent postreplicational repair pathway that repairs the discontinuities that form in the DNA synthesized from damaged templates. Although translesion synthesis is well characterized, little is known about the mechanisms that modulat...

  3. Dbl2 Regulates Rad51 and DNA Joint Molecule Metabolism to Ensure Proper Meiotic Chromosome Segregation.

    Polakova, Silvia; Molnarova, Lucia; Hyppa, Randy W; Benko, Zsigmond; Misova, Ivana; Schleiffer, Alexander; Smith, Gerald R; Gregan, Juraj

    2016-06-01

    To identify new proteins required for faithful meiotic chromosome segregation, we screened a Schizosaccharomyces pombe deletion mutant library and found that deletion of the dbl2 gene led to missegregation of chromosomes during meiosis. Analyses of both live and fixed cells showed that dbl2Δ mutant cells frequently failed to segregate homologous chromosomes to opposite poles during meiosis I. Removing Rec12 (Spo11 homolog) to eliminate meiotic DNA double-strand breaks (DSBs) suppressed the segregation defect in dbl2Δ cells, indicating that Dbl2 acts after the initiation of meiotic recombination. Analyses of DSBs and Holliday junctions revealed no significant defect in their formation or processing in dbl2Δ mutant cells, although some Rec12-dependent DNA joint molecules persisted late in meiosis. Failure to segregate chromosomes in the absence of Dbl2 correlated with persistent Rad51 foci, and deletion of rad51 or genes encoding Rad51 mediators also suppressed the segregation defect of dbl2Δ. Formation of foci of Fbh1, an F-box helicase that efficiently dismantles Rad51-DNA filaments, was impaired in dbl2Δ cells. Our results suggest that Dbl2 is a novel regulator of Fbh1 and thereby Rad51-dependent DSB repair required for proper meiotic chromosome segregation and viable sex cell formation. The wide conservation of these proteins suggests that our results apply to many species. PMID:27304859

  4. Performance comparison of quantitative semantic features and lung-RADS in the National Lung Screening Trial

    Li, Qian; Balagurunathan, Yoganand; Liu, Ying; Schabath, Matthew; Gillies, Robert J.

    2016-03-01

    Background: Lung-RADS is the new oncology classification guideline proposed by American College of Radiology (ACR), which provides recommendation for further follow up in lung cancer screening. However, only two features (solidity and size) are included in this system. We hypothesize that additional sematic features can be used to better characterize lung nodules and diagnose cancer. Objective: We propose to develop and characterize a systematic methodology based on semantic image traits to more accurately predict occurrence of cancerous nodules. Methods: 24 radiological image traits were systematically scored on a point scale (up to 5) by a trained radiologist, and lung-RADS was independently scored. A linear discriminant model was used on the semantic features to access their performance in predicting cancer status. The semantic predictors were then compared to lung-RADS classification in 199 patients (60 cancers, 139 normal controls) obtained from the National Lung Screening Trial. Result: There were different combinations of semantic features that were strong predictors of cancer status. Of these, contour, border definition, size, solidity, focal emphysema, focal fibrosis and location emerged as top candidates. The performance of two semantic features (short axial diameter and contour) had an AUC of 0.945, and was comparable to that of lung-RADS (AUC: 0.871). Conclusion: We propose that a semantics-based discrimination approach may act as a complement to the lung-RADS to predict cancer status.

  5. Multiple Rad5 activities mediate sister chromatid recombination to bypass DNA damage at stalled replication forks.

    Minca, Eugen C; Kowalski, David

    2010-06-11

    DNA damage that blocks replication is bypassed in order to complete chromosome duplication and preserve cell viability and genome stability. Rad5, a PCNA polyubiquitin ligase and DNA-dependent ATPase in yeast, is orthologous to putative tumor suppressors and controls error-free damage bypass by an unknown mechanism. To identify the mechanism in vivo, we investigated the roles of Rad5 and analyzed the DNA structures that form during damage bypass at site-specific stalled forks present at replication origins. Rad5 mediated the formation of recombination-dependent, X-shaped DNA structures containing Holliday junctions between sister chromatids. Mutants lacking these damage-induced chromatid junctions were defective in resolving stalled forks, restarting replication, and completing chromosome duplication. Rad5 polyubiquitin ligase and ATPase domains both contributed to replication fork recombination. Our results indicate that multiple activities of Rad5 function coordinately with homologous recombination factors to enable replication template switch events that join sister chromatids at stalled forks and bypass DNA damage. PMID:20541998

  6. RadNotes: a novel software development tool for radiology education.

    Baxter, A B; Klein, J S; Oesterle, E V

    1997-01-01

    RadNotes is a novel software development tool that enables physicians to develop teaching materials incorporating text and images in an intelligent, highly usable format. Projects undertaken in the RadNotes environment require neither programming expertise nor the assistance of a software engineer. The first of these projects, Thoracic Imaging, integrates image teaching files, concise disease and topic summaries, references, and flash card quizzes into a single program designed to provide an overview of chest radiology. RadNotes is intended to support the academic goals of teaching radiologists by enabling authors to create, edit, and electronically distribute image-oriented presentations. RadNotes also supports the educational goals of physicians who wish to quickly review selected imaging topics, as well as to develop a visual vocabulary of corresponding radiologic anatomy and pathologic conditions. Although Thoracic Imaging was developed with the aim of introducing chest radiology to residents, RadNotes can be used to develop tutorials and image-based tests for all levels; create corresponding World Wide Web sites; and organize notes, images, and references for individual use. PMID:9153710

  7. Resolving RAD51C function in late stages of homologous recombination

    Kuznetsov Sergey G

    2007-06-01

    Full Text Available Abstract DNA double strand breaks are efficiently repaired by homologous recombination. One of the last steps of this process is resolution of Holliday junctions that are formed at the sites of genetic exchange between homologous DNA. Although various resolvases with Holliday junctions processing activity have been identified in bacteriophages, bacteria and archaebacteria, eukaryotic resolvases have been elusive. Recent biochemical evidence has revealed that RAD51C and XRCC3, members of the RAD51-like protein family, are involved in Holliday junction resolution in mammalian cells. However, purified recombinant RAD51C and XRCC3 proteins have not shown any Holliday junction resolution activity. In addition, these proteins did not reveal the presence of a nuclease domain, which raises doubts about their ability to function as a resolvase. Furthermore, oocytes from infertile Rad51C mutant mice exhibit precocious separation of sister chromatids at metaphase II, a phenotype that reflects a defect in sister chromatid cohesion, not a lack of Holliday junction resolution. Here we discuss a model to explain how a Holliday junction resolution defect can lead to sister chromatid separation in mouse oocytes. We also describe other recent in vitro and in vivo evidence supporting a late role for RAD51C in homologous recombination in mammalian cells, which is likely to be resolution of the Holliday junction.

  8. Kinetic gating mechanism of DNA damage recognition by Rad4/XPC

    Chen, Xuejing; Velmurugu, Yogambigai; Zheng, Guanqun; Park, Beomseok; Shim, Yoonjung; Kim, Youngchang; Liu, Lili; van Houten, Bennett; He, Chuan; Ansari, Anjum; Min, Jung-Hyun

    2015-01-01

    The xeroderma pigmentosum C (XPC) complex initiates nucleotide excision repair by recognizing DNA lesions before recruiting downstream factors. How XPC detects structurally diverse lesions embedded within normal DNA is unknown. Here we present a crystal structure that captures the yeast XPC orthologue (Rad4) on a single register of undamaged DNA. The structure shows that a disulphide-tethered Rad4 flips out normal nucleotides and adopts a conformation similar to that seen with damaged DNA. Contrary to many DNA repair enzymes that can directly reject non-target sites as structural misfits, our results suggest that Rad4/XPC uses a kinetic gating mechanism whereby lesion selectivity arises from the kinetic competition between DNA opening and the residence time of Rad4/XPC per site. This mechanism is further supported by measurements of Rad4-induced lesion-opening times using temperature-jump perturbation spectroscopy. Kinetic gating may be a general mechanism used by site-specific DNA-binding proteins to minimize time-consuming interrogations of non-target sites.

  9. Metabolic suppressors of trimethoprim and ultraviolet light sensitivities of Saccharomyces cerevisiae rad6 mutants

    Dominant mutations at two newly identified loci, designated SRS1 and SRS2, that metabolically suppress the trimethoprim sensitivity of rad6 and rad18 strains, have been isolated from trimethorprim-resistant mutants arising spontaneously in rad6-1 rad18-2 strains of the yeast Saccharomyces cerevisiae. The SRS2 mutations also efficiently suppress the ultraviolet light sensitivity of the parent strains. They do not, however, suppress their sensitivity to ionizing radiation or their deficiency with respect to induced mutagenesis and sporulation. Such observations support the hypothesis that RAD6-dependent activities can be separated into two functionally distinct groups: a group of error-free repair activities that are responsible for a large amount of the radiation resistance of wild-type strains and also for their resistance to trimethoprim, and a group of error-prone activities that are responsible for induced mutagenesis and are also important in sporulation, but which account at best for only a very small amount of wild-type recovery

  10. Improving societal acceptance of rad waste management policy decisions: an approach based on complex intelligence

    In today's context elaborate public participation exercises are conducted around the world to elicit and incorporate societal risk perceptions into nuclear policy Decision-Making. However, on many occasions, such as in the case of rad waste management, the society remains unconvinced about these decisions. This naturally leads to the questions: are techniques for incorporating societal risk perceptions into the rad waste policy decision making processes sufficiently mature? How could societal risk perceptions and legal normative principles be better integrated in order to render the decisions more equitable and convincing to society? Based on guidance from socio-psychological research this paper postulates that a critical factor for gaining/improving societal acceptance is the quality and adequacy of criteria for option evaluation that are used in the policy decision making. After surveying three rad waste public participation cases, the paper identifies key lacunae in criteria abstraction processes as currently practiced. A new policy decision support model CIRDA: Complex Intelligent Risk Discourse Abstraction model that is based on the heuristic of Risk-Risk Analysis is proposed to overcome these lacunae. CIRDA's functionality of rad waste policy decision making is modelled as a policy decision-making Abstract Intelligent Agent and the agent program/abstraction mappings are presented. CIRDA is then applied to a live (U.K.) rad waste management case and the advantages of this method as compared to the Value Tree Method as practiced in the GB case are demonstrated. (author)