WorldWideScience

Sample records for history dependent damage

  1. History-Dependent Risk Attitude, Second Version

    OpenAIRE

    David Dillenberger; Kareen Rozen

    2011-01-01

    We propose a model of history-dependent risk attitude, allowing a decision maker’s risk attitude to be affected by his history of disappointments and elations. The decision maker recursively evaluates compound risks, classifying realizations as disappointing or elating using a threshold rule. We establish equivalence between the model and two cognitive biases: risk attitudes are reinforced by experiences (one is more risk averse after disappointment than after elation) and there is a primacy ...

  2. Ductile Damage Evolution and Strain Path Dependency

    International Nuclear Information System (INIS)

    Tasan, C. C.; Hoefnagels, J. M. P.; Peerlings, R. H. J.; Geers, M. G. D.; ten Horn, C. H. L. J.; Vegter, H.

    2007-01-01

    Forming limit diagrams are commonly used in sheet metal industry to define the safe forming regions. These diagrams are built to define the necking strains of sheet metals. However, with the rise in the popularity of advance high strength steels, ductile fracture through damage evolution has also emerged as an important parameter in the determination of limit strains. In this work, damage evolution in two different steels used in the automotive industry is examined to observe the relationship between damage evolution and the strain path that is followed during the forming operation

  3. Ductile damage evolution and strain path dependency

    NARCIS (Netherlands)

    Tasan, C.C.; Hoefnagels, J.P.M.; Peerlings, R.H.J.; Geers, M.G.D.; Horn, ten C.H.L.J.; Vegter, H.; Cueto, E.; Chinesta, F.

    2007-01-01

    Forming limit diagrams are commonly used in sheet metal industry to define the safe forming regions. These diagrams are built to define the necking strains of sheet metals. However, with the rise in the popularity of advance high strength steels, ductile fracture through damage evolution has also

  4. Surface treatment and history-dependent corrosion in lead alloys

    International Nuclear Information System (INIS)

    Li Ning; Zhang Jinsuo; Sencer, Bulent H.; Koury, Daniel

    2006-01-01

    In oxygen-controlled lead and lead-bismuth eutectic (LBE), steel corrosion may be strongly history dependent. This is due to the competition between liquid metal dissolution corrosion and oxidation as a 'self-healing' protection barrier. Such effects can be observed from corrosion testing of a variety of surface-treated materials, such as cold working, shot peening, pre-oxidation, etc. Shot peening of austenitic steels produces surface-layer microstructural damages and grain compression, which could contribute to increased Cr migration to the surface and enhance the protection through an impervious oxide. Pre-oxidation under conditions different from operating ones may form more protective oxides, reduce oxygen and metal ion migration through the oxides, and achieve better protection for longer durations. Corrosion and oxidation modeling and analysis reveal the potential for significantly reducing long-term corrosion rates by initial and early-stage conditioning of steels for Pb/LBE services

  5. Surface treatment and history-dependent corrosion in lead alloys

    Energy Technology Data Exchange (ETDEWEB)

    Li Ning [Los Alamos National Laboratory, Los Alamos, NM (United States)]. E-mail: ningli@lanl.gov; Zhang Jinsuo [Los Alamos National Laboratory, Los Alamos, NM (United States); Sencer, Bulent H. [Los Alamos National Laboratory, Los Alamos, NM (United States); Koury, Daniel [University of Nevada, Las Vegas, NV (United States)

    2006-06-23

    In oxygen-controlled lead and lead-bismuth eutectic (LBE), steel corrosion may be strongly history dependent. This is due to the competition between liquid metal dissolution corrosion and oxidation as a 'self-healing' protection barrier. Such effects can be observed from corrosion testing of a variety of surface-treated materials, such as cold working, shot peening, pre-oxidation, etc. Shot peening of austenitic steels produces surface-layer microstructural damages and grain compression, which could contribute to increased Cr migration to the surface and enhance the protection through an impervious oxide. Pre-oxidation under conditions different from operating ones may form more protective oxides, reduce oxygen and metal ion migration through the oxides, and achieve better protection for longer durations. Corrosion and oxidation modeling and analysis reveal the potential for significantly reducing long-term corrosion rates by initial and early-stage conditioning of steels for Pb/LBE services.

  6. Energy-dependent proton damage in silicon

    Energy Technology Data Exchange (ETDEWEB)

    Donegani, Elena Maria

    2017-09-29

    Non Ionizing Energy Loss (NIEL) in the sensor bulk is a limiting factor for the lifetime of silicon detectors. In this work, the proton-energy dependent bulkdamage is studied in n- and p-type silicon pad diodes. The samples are thin (200 μm thick), and oxygen enriched (bulk material types: MCz, standard or deepdiffused FZ). Irradiations are performed with 23 MeV, 188 MeV and 23 GeV protons; the 1 MeV neutron equivalent fluence assumes selected values in the range [0.1,3].10{sup 14} cm{sup -2}. In reverse bias, Current-Voltage (IV) and Capacitance-Voltage (CV) measurements are performed to electrically characterise the samples; in forward bias, IV and CV measurements point out the transition from lifetime to relaxationlike semiconductor after irradiation. By means of Thermally Stimulated Current (TSC) measurements, 13 bulk defects have been found after proton irradiation. Firstly, TSC spectra are analysed to obtain defect concentrations after defect filling at the conventional temperature T{sub fill} =10 K. Secondly, temperature dependent capture coefficients of bulk defects are explained, according to the multi-phonon process, from the analysis of TSC measurements at higher filling temperatures (T{sub fill}<130 K). Thirdly, a new method based on the SRH statistics and accounting for cluster-induced shift in activation energy is proposed; it allows to fully characterise bulk defects (in terms of activation energy, concentration and majority capture cross-section) and to distinguish between point- and cluster-like defects. A correlation is noted between the leakage current and the concentration of three deep defects (namely the V{sub 2}, V{sub 3} and H(220K) defects), for all the investigated bulk materials and types, and after all the considered proton energies and fluences. At least five defects are found to be responsible for the space charge, with positive contributions from the E(30K) and B{sub i}O{sub i} defects, or negative contributions from three deep

  7. Energy-dependent proton damage in silicon

    International Nuclear Information System (INIS)

    Donegani, Elena Maria

    2017-01-01

    Non Ionizing Energy Loss (NIEL) in the sensor bulk is a limiting factor for the lifetime of silicon detectors. In this work, the proton-energy dependent bulkdamage is studied in n- and p-type silicon pad diodes. The samples are thin (200 μm thick), and oxygen enriched (bulk material types: MCz, standard or deepdiffused FZ). Irradiations are performed with 23 MeV, 188 MeV and 23 GeV protons; the 1 MeV neutron equivalent fluence assumes selected values in the range [0.1,3].10 14 cm -2 . In reverse bias, Current-Voltage (IV) and Capacitance-Voltage (CV) measurements are performed to electrically characterise the samples; in forward bias, IV and CV measurements point out the transition from lifetime to relaxationlike semiconductor after irradiation. By means of Thermally Stimulated Current (TSC) measurements, 13 bulk defects have been found after proton irradiation. Firstly, TSC spectra are analysed to obtain defect concentrations after defect filling at the conventional temperature T fill =10 K. Secondly, temperature dependent capture coefficients of bulk defects are explained, according to the multi-phonon process, from the analysis of TSC measurements at higher filling temperatures (T fill <130 K). Thirdly, a new method based on the SRH statistics and accounting for cluster-induced shift in activation energy is proposed; it allows to fully characterise bulk defects (in terms of activation energy, concentration and majority capture cross-section) and to distinguish between point- and cluster-like defects. A correlation is noted between the leakage current and the concentration of three deep defects (namely the V 2 , V 3 and H(220K) defects), for all the investigated bulk materials and types, and after all the considered proton energies and fluences. At least five defects are found to be responsible for the space charge, with positive contributions from the E(30K) and B i O i defects, or negative contributions from three deep acceptors H(116K), H(140K) and H(152K).

  8. A plastic damage model with stress triaxiality-dependent hardening

    International Nuclear Information System (INIS)

    Shen Xinpu; Shen Guoxiao; Zhou Lin

    2005-01-01

    Emphases of this study were placed on the modelling of plastic damage behaviour of prestressed structural concrete, with special attention being paid to the stress-triaxiality dependent plastic hardening law and the corresponding damage evolution law. A definition of stress triaxiality was proposed and introduced in the model presented here. Drucker-Prager -type plasticity was adopted in the formulation of the plastic damage constitutive equations. Numerical validations were performed for the proposed plasticity-based damage model with a driver subroutine developed in this study. The predicted stress-strain behaviour seems reasonably accurate for the uniaxial tension and uniaxial compression compared with the experimental data reported in references. Numerical calculations of compressions under various hydrostatic stress confinements were carried out in order to validate the stress triaxiality dependent properties of the model. (authors)

  9. Dependence of displacement fields on the damage cluster nucleus geometry

    International Nuclear Information System (INIS)

    Grigor'ev, A.N.; Zabela, A.G.; Nikolajchuk, L.I.; Prokhorenko, E.M.; Khizhnyak, N.A.

    1988-01-01

    Displacement fields in doped crystals of cubic and hexagonal structures containing extended defects are studied. The numerical results are presented depending on the damage cluster nucleus geometry. All calculations are based on analytical representations of displacement fields in an integral form using elasticity theory equations. The investigation results are vital for radiation physics as they permit to predict and calculate both the character and geometry of distortions near damaged region cluster and determine cluster parameters on the basis of the known structure of distortions. Dependences are obtained for the following monocrystals: Mg, ZnO, CdS, W, Au. 6 refs.; 3 figs

  10. History-dependent stochastic Petri nets

    NARCIS (Netherlands)

    Schonenberg, H.; Sidorova, N.; Aalst, van der W.M.P.; Hee, van K.M.; Pnueli, A.; Virbitskaite, I.; Voronkov, A.

    2010-01-01

    Stochastic Petri Nets are a useful and well-known tool for performance analysis. However, an implicit assumption in the different types of Stochastic Petri Nets is the Markov property. It is assumed that a choice in the Petri net only depends on the current state and not on earlier choices. For many

  11. Dependence of Glass Mechanical Properties on Thermal and Pressure History

    DEFF Research Database (Denmark)

    Smedskjær, Morten Mattrup; Bauchy, Mathieu

    Predicting the properties of new glasses prior to manufacturing is a topic attracting great industrial and scientific interest. Mechanical properties are currently of particular interest given the increasing demand for stronger, thinner, and more flexible glasses in recent years. However, as a non......-equilibrium material, the structure and properties of glass depend not only on its composition, but also on its thermal and pressure histories. Here we review our recent findings regarding the thermal and pressure history dependence of indentation-derived mechanical properties of oxide glasses....

  12. History dependent quantum random walks as quantum lattice gas automata

    Energy Technology Data Exchange (ETDEWEB)

    Shakeel, Asif, E-mail: asif.shakeel@gmail.com, E-mail: dmeyer@math.ucsd.edu, E-mail: plove@haverford.edu; Love, Peter J., E-mail: asif.shakeel@gmail.com, E-mail: dmeyer@math.ucsd.edu, E-mail: plove@haverford.edu [Department of Physics, Haverford College, Haverford, Pennsylvania 19041 (United States); Meyer, David A., E-mail: asif.shakeel@gmail.com, E-mail: dmeyer@math.ucsd.edu, E-mail: plove@haverford.edu [Department of Mathematics, University of California/San Diego, La Jolla, California 92093-0112 (United States)

    2014-12-15

    Quantum Random Walks (QRW) were first defined as one-particle sectors of Quantum Lattice Gas Automata (QLGA). Recently, they have been generalized to include history dependence, either on previous coin (internal, i.e., spin or velocity) states or on previous position states. These models have the goal of studying the transition to classicality, or more generally, changes in the performance of quantum walks in algorithmic applications. We show that several history dependent QRW can be identified as one-particle sectors of QLGA. This provides a unifying conceptual framework for these models in which the extra degrees of freedom required to store the history information arise naturally as geometrical degrees of freedom on the lattice.

  13. History dependence in insect flight decisions during odor tracking.

    Science.gov (United States)

    Pang, Rich; van Breugel, Floris; Dickinson, Michael; Riffell, Jeffrey A; Fairhall, Adrienne

    2018-02-01

    Natural decision-making often involves extended decision sequences in response to variable stimuli with complex structure. As an example, many animals follow odor plumes to locate food sources or mates, but turbulence breaks up the advected odor signal into intermittent filaments and puffs. This scenario provides an opportunity to ask how animals use sparse, instantaneous, and stochastic signal encounters to generate goal-oriented behavioral sequences. Here we examined the trajectories of flying fruit flies (Drosophila melanogaster) and mosquitoes (Aedes aegypti) navigating in controlled plumes of attractive odorants. While it is known that mean odor-triggered flight responses are dominated by upwind turns, individual responses are highly variable. We asked whether deviations from mean responses depended on specific features of odor encounters, and found that odor-triggered turns were slightly but significantly modulated by two features of odor encounters. First, encounters with higher concentrations triggered stronger upwind turns. Second, encounters occurring later in a sequence triggered weaker upwind turns. To contextualize the latter history dependence theoretically, we examined trajectories simulated from three normative tracking strategies. We found that neither a purely reactive strategy nor a strategy in which the tracker learned the plume centerline over time captured the observed history dependence. In contrast, "infotaxis", in which flight decisions maximized expected information gain about source location, exhibited a history dependence aligned in sign with the data, though much larger in magnitude. These findings suggest that while true plume tracking is dominated by a reactive odor response it might also involve a history-dependent modulation of responses consistent with the accumulation of information about a source over multi-encounter timescales. This suggests that short-term memory processes modulating decision sequences may play a role in

  14. Enhanced intensity dependence and aggression history indicate previous regular ecstasy use in abstinent polydrug users.

    Science.gov (United States)

    Wan, Li; Baldridge, Robyn M; Colby, Amanda M; Stanford, Matthew S

    2009-11-13

    Intensity dependence is an electrophysiological measure of intra-individual stability of the augmenting/reducing characteristic of N1/ P2 event-related potential amplitudes in response to stimuli of varying intensities. Abstinent ecstasy users typically show enhanced intensity dependence and higher levels of impulsivity and aggression. Enhanced intensity dependence and high impulsivity and aggression levels may be due to damage in the brain's serotonergic neurons as a result of ecstasy use. The present study investigated whether intensity dependence, impulsivity and aggression history can be used as indicators of previous chronic ecstasy usage. Forty-four abstinent polydrug users (8 women; age 19 to 61 years old) were recruited. All participants were currently residents at a local substance abuse facility receiving treatment and had been free of all drugs for a minimum of 21 days. The study found significantly enhanced intensity dependence of tangential dipole source activity and a history of more aggressive behavior in those who had previously been involved in chronic ecstasy use. Intensity dependence of the tangential dipole source and aggressive behavior history correctly identified 73.3% of those who had been regular ecstasy users and 78.3% of those who had not. Overall, 76.3% of the participants were correctly classified.

  15. Cell-cycle-dependent repair of heavy-ion damage

    International Nuclear Information System (INIS)

    Blakely, E.A.; Chang, P.Y.; Lommel, L.; Tobias, C.A.

    1985-01-01

    Synchronized human T-1 cells have been used to investigate the G1-phase age dependence of repair of potentially lethal damage (PLDR). The cells were irradiated with single doses of either 225 kVp X rays or Bragg-peak 425 MeV/μ neon ions at ages between 1.5 and 6.0 hrs after mitotic selection, and then either trypsinized and plated immediately, or held at 37 0 C for 6 hrs in PBS, or PBS containing 60μM of the DNA-polymerase-inhibitor 1-β-D-arabinofurano-syladenine (β-araA) before trypsinization and plating. Delayed plating showed significant PLDR at all ages irradiated with X rays, with the increase of survival varying between 2- to 8-fold. At equivalent survival levels, there was a reduced capacity for PLDT at each cell age irradiated with neon ions. In early G1 after neon-ion exposures, delayed plating actually enhanced cell killing; whereas, in late G1 the survival increased about 2-fold. β-araA almost completely eliminated the PLDR after X rays, reducing the survival to that measured with immediate plating. β-araA slightly enhanced neon-ion cell killing at all cell ages

  16. A particle method for history-dependent materials

    Energy Technology Data Exchange (ETDEWEB)

    Sulsky, D.; Chen, Z.; Schreyer, H.L. [New Mexico Univ., Albuquerque, NM (United States)

    1993-06-01

    A broad class of engineering problems including penetration, impact and large rotations of solid bodies causes severe numerical problems. For these problems, the constitutive equations are history dependent so material points must be followed; this is difficult to implement in an Eulerian scheme. On the other hand, purely Lagrangian methods typically result in severe mesh distortion and the consequence is ill conditioning of the element stiffness matrix leading to mesh lockup or entanglement. Remeshing prevents the lockup and tangling but then interpolation must be performed for history dependent variables, a process which can introduce errors. Proposed here is an extension of the particle-in-cell method in which particles are interpreted to be material points that are followed through the complete loading process. A fixed Eulerian grid provides the means for determining a spatial gradient. Because the grid can also be interpreted as an updated Lagrangian frame, the usual convection term in the acceleration associated with Eulerian formulations does not appear. With the use of maps between material points and the grid, the advantages of both Eulerian and Lagrangian schemes are utilized so that mesh tangling is avoided while material variables are tracked through the complete deformation history. Example solutions in two dimensions are given to illustrate the robustness of the proposed convection algorithm and to show that typical elastic behavior can be reproduced. Also, it is shown that impact with no slip is handled without any special algorithm for bodies governed by elasticity and strain hardening plasticity.

  17. Time-Dependent Damage Investigation of Rock Mass in an In Situ Experimental Tunnel

    Science.gov (United States)

    Jiang, Quan; Cui, Jie; Chen, Jing

    2012-01-01

    In underground tunnels or caverns, time-dependent deformation or failure of rock mass, such as extending cracks, gradual rock falls, etc., are a costly irritant and a major safety concern if the time-dependent damage of surrounding rock is serious. To understand the damage evolution of rock mass in underground engineering, an in situ experimental testing was carried out in a large belowground tunnel with a scale of 28.5 m in width, 21 m in height and 352 m in length. The time-dependent damage of rock mass was detected in succession by an ultrasonic wave test after excavation. The testing results showed that the time-dependent damage of rock mass could last a long time, i.e., nearly 30 days. Regression analysis of damage factors defined by wave velocity, resulted in the time-dependent evolutional damage equation of rock mass, which corresponded with logarithmic format. A damage viscoelastic-plastic model was developed to describe the exposed time-dependent deterioration of rock mass by field test, such as convergence of time-dependent damage, deterioration of elastic modules and logarithmic format of damage factor. Furthermore, the remedial measures for damaged surrounding rock were discussed based on the measured results and the conception of damage compensation, which provides new clues for underground engineering design.

  18. Adaptive Smoothed Finite Elements (ASFEM) for history dependent material models

    International Nuclear Information System (INIS)

    Quak, W.; Boogaard, A. H. van den

    2011-01-01

    A successful simulation of a bulk forming process with finite elements can be difficult due to distortion of the finite elements. Nodal smoothed Finite Elements (NSFEM) are an interesting option for such a process since they show good distortion insensitivity and moreover have locking-free behavior and good computational efficiency. In this paper a method is proposed which takes advantage of the nodally smoothed field. This method, named adaptive smoothed finite elements (ASFEM), revises the mesh for every step of a simulation without mapping the history dependent material parameters. In this paper an updated-Lagrangian implementation is presented. Several examples are given to illustrate the method and to show its properties.

  19. Situation-dependent repair of DNA damage in yeast

    International Nuclear Information System (INIS)

    von Borstel, R.C.; Hastings, P.J.

    1985-01-01

    The concept of channelling of lesions in DNA into defined repair systems has been used to explain many aspects of induced and spontaneous mutation. The channelling hypothesis states that lesions excluded from one repair process will be taken up by another repair process. This is a simplification. The three known modes of repair of damage induced by radiation are not equivalent modes of repair; they are, instead, different solutions to the problem of replacement of damaged molecules with new molecules which have the same informational content as those that were damaged. The mode of repair that is used is the result of the response to the situation in which the damage takes place. Thus, when the most likely mode of repair does not take place, then the situation changes with respect to the repair of the lesion; the lesion may enter the replication fork and be reparable by another route

  20. The dependence of radiation damage analysis on neutron dosimetry

    International Nuclear Information System (INIS)

    Goland, A.N.; Parkin, D.M.

    1977-01-01

    The characteristics of defect production in neutron spectra can be determined by utilizing neutron cross section data (e.g. ENDF/B), detailed neutron spectral data and radiation damage models. The combination of neutron cross section and spectral data is a fundamental starting point in applying damage models. Calculations using these data and damage models show that there are significant differences in the way defects are produced in various neutron spectra. Nonelastic events dominate the recoil energy distribution in high-energy neutron sources such as those based upon fusion and deuteron-breakup reactions. Therefore, high-energy neutron cross sections must be measured or calculated to supplement existing data files. Radiation damage models can then be used to further characterize the diverse neutron spectra

  1. A Lattice-Misfit-Dependent Damage Model for Non-linear Damage Accumulations Under Monotonous Creep in Single Crystal Superalloys

    Science.gov (United States)

    le Graverend, J.-B.

    2018-05-01

    A lattice-misfit-dependent damage density function is developed to predict the non-linear accumulation of damage when a thermal jump from 1050 °C to 1200 °C is introduced somewhere in the creep life. Furthermore, a phenomenological model aimed at describing the evolution of the constrained lattice misfit during monotonous creep load is also formulated. The response of the lattice-misfit-dependent plasticity-coupled damage model is compared with the experimental results obtained at 140 and 160 MPa on the first generation Ni-based single crystal superalloy MC2. The comparison reveals that the damage model is well suited at 160 MPa and less at 140 MPa because the transfer of stress to the γ' phase occurs for stresses above 150 MPa which leads to larger variations and, therefore, larger effects of the constrained lattice misfit on the lifetime during thermo-mechanical loading.

  2. Damage Level Prediction of Reinforced Concrete Building Based on Earthquake Time History Using Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Suryanita Reni

    2017-01-01

    Full Text Available The strong motion earthquake could cause the building damage in case of the building not considered in the earthquake design of the building. The study aims to predict the damage-level of building due to earthquake using Artificial Neural Networks method. The building model is a reinforced concrete building with ten floors and height between floors is 3.6 m. The model building received a load of the earthquake based on nine earthquake time history records. Each time history scaled to 0,5g, 0,75g, and 1,0g. The Artificial Neural Networks are designed in 4 architectural models using the MATLAB program. Model 1 used the displacement, velocity, and acceleration as input and Model 2 used the displacement only as the input. Model 3 used the velocity as input, and Model 4 used the acceleration just as input. The output of the Neural Networks is the damage level of the building with the category of Safe (1, Immediate Occupancy (2, Life Safety (3 or in a condition of Collapse Prevention (4. According to the results, Neural Network models have the prediction rate of the damage level between 85%-95%. Therefore, one of the solutions for analyzing the structural responses and the damage level promptly and efficiently when the earthquake occurred is by using Artificial Neural Network

  3. Peroxidative damage of mitochondrial respiration is substrate-dependent

    Czech Academy of Sciences Publication Activity Database

    Endlicher, R.; Křiváková, P.; Rauchová, Hana; Nůsková, Hana; Červinková, Z.; Drahota, Zdeněk

    2009-01-01

    Roč. 58, č. 5 (2009), s. 685-692 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GA303/06/1261 Institutional research plan: CEZ:AV0Z50110509 Keywords : mitochondrial enzymes * peroxidative damage * tert-butyl hydroperoxide Subject RIV: CE - Biochemistry Impact factor: 1.430, year: 2009

  4. Temperature dependence of damage accumulation in α-zirconium

    International Nuclear Information System (INIS)

    Arevalo, C.; Caturla, M.J.; Perlado, J.M.

    2007-01-01

    Using the input data obtained from molecular dynamics (MD) simulations on defect energetics and cascade damage, we present results obtained on irradiation of hexagonal-close-packed (hcp) α-zirconium under different conditions with a kinetic Monte Carlo (kMC) model. We used three 25 keV cascade databases at temperatures of 100 K, 300 K and 600 K respectively. The evolution of the microstructure during irradiation for a dose rate of 10 -6 dpa/s, at temperatures of 100 K, 300 K and 600 K until a final dose of 0.1 dpa has been studied. We have considered isotropic motion for vacancies and one dimensional movement for interstitials and we have studied how the accumulation of damage is affected considering different temperatures. We present preliminary comparisons with experimental data

  5. DNA Damage Observed in Unaffected Individuals with Family History of T2DM

    Science.gov (United States)

    Ramesh, Nikhila; Abilash, V. G.

    2017-11-01

    Diabetes has been documented to cause high levels of DNA fragmentation in some cases. As diabetes is inheritable and influenced by both genetic and environmental factors, an investigation into the genomic stability of individuals who are strongly at risk of inheriting diabetes was conducted by inducing oxidative stress, as DNA damage in unaffected individuals could be a sign of onset of the disease or the presence of genetic alterations that reduce cellular defences against reactive oxygen species. In this study, alkaline comet assay was performed on isolated human leukocytes to determine whether individuals with a family history of Type 2 Diabetes Mellitus (T2DM) are more prone to DNA damage under oxidative stress. Visual scoring of comets showed that these individuals have higher degree of DNA damage compared to a control individual with no family history of Type 2 Diabetes Mellitus. Further studies with large sample could determine the presence of disabled cellular defences against oxidative stress in unaffected individuals and intervention with antioxidants could prevent or manage Type 2 Diabetes Mellitus and its complications.

  6. Energy Dependence of Proton Radiation Damage in Si-Sensors

    CERN Document Server

    AUTHOR|(CDS)2084399; Neubüser, C.

    2014-01-01

    Irradiation experiments on silicon sensors are used to mimic the radiation environment at collider experiments with the aim to forecast the change of the electrical properties of a detector with irradiation. Measurements on irradiated sensors are invaluable in choosing a material well suited for a silicon tracking detector. This is especially true for the upgraded detectors to be used in the high-luminosity phase of the LHC (HL-LHC), where silicon sensors as currently used would suffer severe loss in signal from irradiation with charged and neutral hadrons.\\\\ The CMS Tracker Collaboration has initiated irradiation studies with protons with energies ranging from 23 MeV to 23 GeV. They are often used instead of charged hadrons, their radiation induced damage to the silicon being rather similar. However, in oxygen rich silicon, NIEL violation concerning the full depletion voltage has been observed.\\\\ In this paper results from investigations on bulk defects compared to the change of the electrical properties of ...

  7. Characterization of the energy-dependent uncertainty and correlation in silicon neutron displacement damage metrics

    Directory of Open Access Journals (Sweden)

    Griffin Patrick

    2017-01-01

    Full Text Available A rigorous treatment of the uncertainty in the underlying nuclear data on silicon displacement damage metrics is presented. The uncertainty in the cross sections and recoil atom spectra are propagated into the energy-dependent uncertainty contribution in the silicon displacement kerma and damage energy using a Total Monte Carlo treatment. An energy-dependent covariance matrix is used to characterize the resulting uncertainty. A strong correlation between different reaction channels is observed in the high energy neutron contributions to the displacement damage metrics which supports the necessity of using a Monte Carlo based method to address the nonlinear nature of the uncertainty propagation.

  8. Fatigue damage estimation using irregularity factor. First report, irregularity factor calculations for narrow and broadband random time histories

    Science.gov (United States)

    Susuki, I.

    1981-11-01

    The results of an analysis of the irregularity factors of stationary and Gaussian random processes which are generated by filtering the output of a pure or a band-limited white noise are presented. An ideal band pass filter, a trapezoidal filter, and a Butterworth type band pass filter were examined. It was found that the values of the irregularity factors were approximately equal among these filters if only the end-slopes were the same rates. As the band width of filters increases, irregularity factors increase monotonically and approach the respective constant values depending on the end-slopes. This implies that the noise characteristics relevant to the fatigue damage such as statistical aspects of the height of the rise and fall or the distribution of the peak values are not changed for a broad band random time history. It was also found that the effect of band limitation of input white noise on irregularity factors is negligibly small.

  9. Strain-dependent Damage Evolution and Velocity Reduction in Fault Zones Induced by Earthquake Rupture

    Science.gov (United States)

    Zhong, J.; Duan, B.

    2009-12-01

    Low-velocity fault zones (LVFZs) with reduced seismic velocities relative to the surrounding wall rocks are widely observed around active faults. The presence of such a zone will affect rupture propagation, near-field ground motion, and off-fault damage in subsequent earth-quakes. In this study, we quantify the reduction of seismic velocities caused by dynamic rup-ture on a 2D planar fault surrounded by a low-velocity fault zone. First, we implement the damage rheology (Lyakhovsky et al. 1997) in EQdyna (Duan and Oglesby 2006), an explicit dynamic finite element code. We further extend this damage rheology model to include the dependence of strains on crack density. Then, we quantify off-fault continuum damage distribution and velocity reduction induced by earthquake rupture with the presence of a preexisting LVFZ. We find that the presence of a LVFZ affects the tempo-spatial distribu-tions of off-fault damage. Because lack of constraint in some damage parameters, we further investigate the relationship between velocity reduction and these damage prameters by a large suite of numerical simulations. Slip velocity, slip, and near-field ground motions computed from damage rheology are also compared with those from off-fault elastic or elastoplastic responses. We find that the reduction in elastic moduli during dynamic rupture has profound impact on these quantities.

  10. History of the Innovation of Damage Control for Management of Trauma Patients: 1902-2016.

    Science.gov (United States)

    Roberts, Derek J; Ball, Chad G; Feliciano, David V; Moore, Ernest E; Ivatury, Rao R; Lucas, Charles E; Fabian, Timothy C; Zygun, David A; Kirkpatrick, Andrew W; Stelfox, Henry T

    2017-05-01

    To review the history of the innovation of damage control (DC) for management of trauma patients. DC is an important development in trauma care that provides a valuable case study in surgical innovation. We searched bibliographic databases (1950-2015), conference abstracts (2009-2013), Web sites, textbooks, and bibliographies for articles relating to trauma DC. The innovation of DC was then classified according to the Innovation, Development, Exploration, Assessment, and Long-term study model of surgical innovation. The "innovation" of DC originated from the use of therapeutic liver packing, a practice that had previously been abandoned after World War II because of adverse events. It then "developed" into abbreviated laparotomy using "rapid conservative operative techniques." Subsequent "exploration" resulted in the application of DC to increasingly complex abdominal injuries and thoracic, peripheral vascular, and orthopedic injuries. Increasing use of DC laparotomy was followed by growing reports of postinjury abdominal compartment syndrome and prophylactic use of the open abdomen to prevent intra-abdominal hypertension after DC laparotomy. By the year 2000, DC surgery had been widely adopted and was recommended for use in surgical journals, textbooks, and teaching courses ("assessment" stage of innovation). "Long-term study" of DC is raising questions about whether the procedure should be used more selectively in the context of improving resuscitation practices. The history of the innovation of DC illustrates how a previously abandoned surgical technique was adapted and readopted in response to an increased understanding of trauma patient physiology and changing injury patterns and trauma resuscitation practices.

  11. Estrogen signalling and the DNA damage response in hormone dependent breast cancers

    Directory of Open Access Journals (Sweden)

    C Elizabeth Caldon

    2014-05-01

    Full Text Available Estrogen is necessary for the normal growth and development of breast tissue, but high levels of estrogen are a major risk factor for breast cancer. One mechanism by which estrogen could contribute to breast cancer is via the induction of DNA damage. This perspective discusses the mechanisms by which estrogen alters the DNA damage response (DDR and DNA repair through the regulation of key effector proteins including ATM, ATR, CHK1, BRCA1 and p53 and the feedback on estrogen receptor signalling from these proteins. We put forward the hypothesis that estrogen receptor signalling converges to suppress effective DNA repair and apoptosis in favour of proliferation. This is important in hormone-dependent breast cancer as it will affect processing of estrogen-induced DNA damage, as well as other genotoxic insults. DDR and DNA repair proteins are frequently mutated or altered in estrogen responsive breast cancer which will further change the processing of DNA damage. Finally the action of estrogen signalling on DNA damage is also relevant to the therapeutic setting as the suppression of a DNA damage response by estrogen has the potential to alter the response of cancers to anti-hormone treatment or chemotherapy that induces DNA damage.

  12. ATP-dependent chromatin remodeling in the DNA-damage response

    Directory of Open Access Journals (Sweden)

    Lans Hannes

    2012-01-01

    Full Text Available Abstract The integrity of DNA is continuously challenged by metabolism-derived and environmental genotoxic agents that cause a variety of DNA lesions, including base alterations and breaks. DNA damage interferes with vital processes such as transcription and replication, and if not repaired properly, can ultimately lead to premature aging and cancer. Multiple DNA pathways signaling for DNA repair and DNA damage collectively safeguard the integrity of DNA. Chromatin plays a pivotal role in regulating DNA-associated processes, and is itself subject to regulation by the DNA-damage response. Chromatin influences access to DNA, and often serves as a docking or signaling site for repair and signaling proteins. Its structure can be adapted by post-translational histone modifications and nucleosome remodeling, catalyzed by the activity of ATP-dependent chromatin-remodeling complexes. In recent years, accumulating evidence has suggested that ATP-dependent chromatin-remodeling complexes play important, although poorly characterized, roles in facilitating the effectiveness of the DNA-damage response. In this review, we summarize the current knowledge on the involvement of ATP-dependent chromatin remodeling in three major DNA repair pathways: nucleotide excision repair, homologous recombination, and non-homologous end-joining. This shows that a surprisingly large number of different remodeling complexes display pleiotropic functions during different stages of the DNA-damage response. Moreover, several complexes seem to have multiple functions, and are implicated in various mechanistically distinct repair pathways.

  13. Molecular Imaging on the Cerebral Pathological Damage Target of Ketamine Dependence

    Directory of Open Access Journals (Sweden)

    YANG Hong-jie1,2;HU Shu1;JIA Shao-wei1;GAO Zhou1;WANG Tong3;ZHAO Zheng-qin1

    2014-02-01

    Full Text Available To study the cerebral pathological damage target which result from abusing ketamine through molecular imaging techniques, 20 cases of ketamine dependent patients looking for treatment at the Peking University Shenzhen Hospital and 31 healthy volunteers were included in this study, all of them got brain SPECT DAT imaging. The results were analyzed by SPSS 16.0. The bilateral caudate nucleus and putamen of healthy volunteers were roughly equally large, and the radioactive distribution of DAT in healthy volunteers were uniform and symmetrical. The bilateral corpora striatum showed typical “panda eyes” pattern. But the bilateral corpora striatum of ketamine dependent patients got smaller in shape, got disorders in pattern, and the radioactive distribution of DAT reduced or defected or even got disturbance and with much more non-specific radioactive. The V, m and Ra of bilateral corpora striatum in ketamine dependent patients were (21.03±3.15) cm3, (22.08±3.31) g and (5.37±1.08) %, respectively, which were significantly lower than the healthy volunteers (p<0.01. The cerebral pathological damage target which resulted from abusing ketamine was similar to those of compound codeine phosphate antitussive solution dependence, heroin dependence and MDMA dependence, all of these psychoactive substances damaged the function of DAT.

  14. Systematic analysis of dependent human errors from the maintenance history at finnish NPPs - A status report

    Energy Technology Data Exchange (ETDEWEB)

    Laakso, K. [VTT Industrial Systems (Finland)

    2002-12-01

    Operating experience has shown missed detection events, where faults have passed inspections and functional tests to operating periods after the maintenance activities during the outage. The causes of these failures have often been complex event sequences, involving human and organisational factors. Especially common cause and other dependent failures of safety systems may significantly contribute to the reactor core damage risk. The topic has been addressed in the Finnish studies of human common cause failures, where experiences on latent human errors have been searched and analysed in detail from the maintenance history. The review of the bulk of the analysis results of the Olkiluoto and Loviisa plant sites shows that the instrumentation and control and electrical equipment is more prone to human error caused failure events than the other maintenance and that plant modifications and also predetermined preventive maintenance are significant sources of common cause failures. Most errors stem from the refuelling and maintenance outage period at the both sites, and less than half of the dependent errors were identified during the same outage. The dependent human errors originating from modifications could be reduced by a more tailored specification and coverage of their start-up testing programs. Improvements could also be achieved by a more case specific planning of the installation inspection and functional testing of complicated maintenance works or work objects of higher plant safety and availability importance. A better use and analysis of condition monitoring information for maintenance steering could also help. The feedback from discussions of the analysis results with plant experts and professionals is still crucial in developing the final conclusions and recommendations that meet the specific development needs at the plants. (au)

  15. Intertemporal Decision Making After Brain Injury: Amount-Dependent Steeper Discounting after Frontal Cortex Damage

    Directory of Open Access Journals (Sweden)

    Białaszek Wojciech

    2017-12-01

    Full Text Available Traumatic brain injuries to the frontal lobes are associated with many maladaptive forms of behavior. We investigated the association between brain damage and impulsivity, as measured by the rate of delay discounting (i.e., the extent to which future outcomes are devalued in time. The main aim of this study was to test the hypothesis of steeper discounting of different amounts in a group of patients with frontal lobe damage. We used a delay discounting task in the form of a structured interview. A total of 117 participants were divided into five groups: three neurological groups and two groups without brain damage. Our analyses showed that patients with focal damage to the frontal lobes demonstrated steeper delay discounting than other participants. Other clinical groups demonstrated similar discounting rates. The data pattern related to the magnitude effect on the group level suggested that the magnitude effect is absent in the group of patients with damage to the frontal lobes; however, results were less consistent on an individual level. Amount-dependent discounting was observed in only two groups, the healthy control group and the neurological group with other cortical areas damaged.

  16. Explaining density-dependent regulation in earthworm populations using life-history analysis

    NARCIS (Netherlands)

    Kammenga, J.E.; Spurgeon, D.J.; Svendsen, C.; Weeks, J.M.

    2003-01-01

    At present there is little knowledge about how density regulates population growth rate and to what extent this is determined by life-history patterns. We compared density dependent population consequences in the Nicholsonian sense based oil experimental observations and life-history modeling for

  17. Dependency of irradiation damage density on tritium migration behaviors in Li2TiO3

    International Nuclear Information System (INIS)

    Kobayashi, Makoto; Toda, Kensuke; Oya, Yasuhisa; Okuno, Kenji

    2014-01-01

    Tritium migration behaviors in Li 2 TiO 3 with the increase of irradiation damage density were investigated by means of electron spin resonance and thermal desorption spectroscopy. The irradiation damages of F + -centers and O − -centers were formed by neutron irradiation, and their damage densities were increased with increasing neutron fluence. Tritium release temperature was clearly shifted toward higher temperature side with increasing neutron fluence, i.e. increasing damage density. The rate determining process for tritium release was also clearly changed depending on the damage density. Tritium release was mainly controlled by tritium diffusion process in crystalline grain of Li 2 TiO 3 at lower neutron fluence. The apparent tritium diffusivity was reduced as the damage density in Li 2 TiO 3 increased due to the introduction of tritium trapping/detrapping sites for diffusing tritium. Then, tritium trapping/detrapping processes began to control the overall tritium release with further damage introductions as the amount of tritium trapping sites increased enough to trap most of tritium in Li 2 TiO 3 . The effects of water vapor in purge gas on tritium release behaviors were also investigated. It was considered that hydrogen isotopes in purge gas would be dissociated and adsorbed on the surface of Li 2 TiO 3 . Then, hydrogen isotopes diffused inward Li 2 TiO 3 would occupy the tritium trapping sites before diffusing tritium reaches to these sites, promoting apparent tritium diffusion consequently. Kinetics analysis of tritium release for highly damaged Li 2 TiO 3 showed that the rate determining process of tritium release was the detrapping process of tritium formed as hydroxyl groups. The rate of tritium detrapping as hydroxyl groups was determined by the kinetic analysis, and was comparable to tritium release kinetics for Li 2 O, LiOH and Li 4 TiO 4 . The dangling oxygen atoms (O − -centers) formed by neutron irradiation would contribute strongly on the

  18. Reliability analysis of Markov history-dependent repairable systems with neglected failures

    International Nuclear Information System (INIS)

    Du, Shijia; Zeng, Zhiguo; Cui, Lirong; Kang, Rui

    2017-01-01

    Markov history-dependent repairable systems refer to the Markov repairable systems in which some states are changeable and dependent on recent evolutional history of the system. In practice, many Markov history-dependent repairable systems are subjected to neglected failures, i.e., some failures do not affect system performances if they can be repaired promptly. In this paper, we develop a model based on the theory of aggregated stochastic processes to describe the history-dependent behavior and the effect of neglected failures on the Markov history-dependent repairable systems. Based on the developed model, instantaneous and steady-state availabilities are derived to characterize the reliability of the system. Four reliability-related time distributions, i.e., distribution for the k th working period, distribution for the k th failure period, distribution for the real working time in an effective working period, distribution for the neglected failure time in an effective working period, are also derived to provide a more comprehensive description of the system's reliability. Thanks to the power of the theory of aggregated stochastic processes, closed-form expressions are obtained for all the reliability indexes and time distributions. Finally, the developed indexes and analysis methods are demonstrated by a numerical example. - Highlights: • Markovian history-dependent repairable systems with neglected failures is modeled. • Aggregated stochastic processes are used to derive reliability indexes and time distributions. • Closed-form expressions are derived for the considered indexes and distributions.

  19. Wavelength dependence of biological damage induced by UV radiation on bacteria.

    Science.gov (United States)

    Santos, Ana L; Oliveira, Vanessa; Baptista, Inês; Henriques, Isabel; Gomes, Newton C M; Almeida, Adelaide; Correia, António; Cunha, Ângela

    2013-01-01

    The biological effects of UV radiation of different wavelengths (UVA, UVB and UVC) were assessed in nine bacterial isolates displaying different UV sensitivities. Biological effects (survival and activity) and molecular markers of oxidative stress [DNA strand breakage (DSB), generation of reactive oxygen species (ROS), oxidative damage to proteins and lipids, and the activity of antioxidant enzymes catalase and superoxide dismutase] were quantified and statistically analyzed in order to identify the major determinants of cell inactivation under the different spectral regions. Survival and activity followed a clear wavelength dependence, being highest under UVA and lowest under UVC. The generation of ROS, as well as protein and lipid oxidation, followed the same pattern. DNA damage (DSB) showed the inverse trend. Multiple stepwise regression analysis revealed that survival under UVA, UVB and UVC wavelengths was best explained by DSB, oxidative damage to lipids, and intracellular ROS levels, respectively.

  20. Non-linear character of dose dependences of chromosome aberration frequency in radiation-damaged root

    International Nuclear Information System (INIS)

    Kravets, E.A.; Berezhnaya, V.V.; Sakada, V.I.; Rashidov, N.M.; Grodzinskij, D.M.; Kravets, E.A.; Berezhnaya, V.V.; Sakada, V.I.; Rashidov, N.M.; Grodzinskij, D.M.

    2012-01-01

    The dose dependences of the aberrant anaphases in the root meristem in 48 hours after the irradiation have non-linear character and a plateau in the region about 6-8 Gy. The plateau indicates the activation of recovery processes. In the plateau range, the level of damages for this genotype is 33% for aberrant anaphases (FAA), 2.3 aberrations per aberrant anaphase (A/AC), and 0.74 aberrations for the total number of anaphases. At 10 Gy, the dose curve forms the exponential region caused by the involvement of the large number of new cells with unrepaired damages in the mutation process. The increase of A/AC to 1.1 indicate the ''criticality'' of the meristem radiation damage.

  1. Shape-dependent bactericidal activity of copper oxide nanoparticle mediated by DNA and membrane damage

    International Nuclear Information System (INIS)

    Laha, Dipranjan; Pramanik, Arindam; Laskar, Aparna; Jana, Madhurya; Pramanik, Panchanan; Karmakar, Parimal

    2014-01-01

    Highlights: • Spherical and sheet shaped copper oxide nanoparticles were synthesized. • Physical characterizations of these nanoparticles were done by TEM, DLS, XRD, FTIR. • They showed shape dependent antibacterial activity on different bacterial strain. • They induced both membrane damage and ROS mediated DNA damage in bacteria. - Abstract: In this work, we synthesized spherical and sheet shaped copper oxide nanoparticles and their physical characterizations were done by the X-ray diffraction, fourier transform infrared spectroscopy, transmission electron microscopy and dynamic light scattering. The antibacterial activity of these nanoparticles was determined on both gram positive and gram negative bacterial. Spherical shaped copper oxide nanoparticles showed more antibacterial property on gram positive bacteria where as sheet shaped copper oxide nanoparticles are more active on gram negative bacteria. We also demonstrated that copper oxide nanoparticles produced reactive oxygen species in both gram negative and gram positive bacteria. Furthermore, they induced membrane damage as determined by atomic force microscopy and scanning electron microscopy. Thus production of and membrane damage are major mechanisms of the bactericidal activity of these copper oxide nanoparticles. Finally it was concluded that antibacterial activity of nanoparticles depend on physicochemical properties of copper oxide nanoparticles and bacterial strain

  2. Shape-dependent bactericidal activity of copper oxide nanoparticle mediated by DNA and membrane damage

    Energy Technology Data Exchange (ETDEWEB)

    Laha, Dipranjan; Pramanik, Arindam [Department of Life Science and Biotechnology, Jadavpur University, 188, Raja S C Mallick Road, Kolkata 700032 (India); Laskar, Aparna [CSIR-Indian Institute of Chemical Biology, Kolkata 700032 (India); Jana, Madhurya [Department of Life Science and Biotechnology, Jadavpur University, 188, Raja S C Mallick Road, Kolkata 700032 (India); Pramanik, Panchanan [Department of Chemistry, Indian Institute of Technology, Kharagpur 721302 (India); Karmakar, Parimal, E-mail: pkarmakar_28@yahoo.co.in [Department of Life Science and Biotechnology, Jadavpur University, 188, Raja S C Mallick Road, Kolkata 700032 (India)

    2014-11-15

    Highlights: • Spherical and sheet shaped copper oxide nanoparticles were synthesized. • Physical characterizations of these nanoparticles were done by TEM, DLS, XRD, FTIR. • They showed shape dependent antibacterial activity on different bacterial strain. • They induced both membrane damage and ROS mediated DNA damage in bacteria. - Abstract: In this work, we synthesized spherical and sheet shaped copper oxide nanoparticles and their physical characterizations were done by the X-ray diffraction, fourier transform infrared spectroscopy, transmission electron microscopy and dynamic light scattering. The antibacterial activity of these nanoparticles was determined on both gram positive and gram negative bacterial. Spherical shaped copper oxide nanoparticles showed more antibacterial property on gram positive bacteria where as sheet shaped copper oxide nanoparticles are more active on gram negative bacteria. We also demonstrated that copper oxide nanoparticles produced reactive oxygen species in both gram negative and gram positive bacteria. Furthermore, they induced membrane damage as determined by atomic force microscopy and scanning electron microscopy. Thus production of and membrane damage are major mechanisms of the bactericidal activity of these copper oxide nanoparticles. Finally it was concluded that antibacterial activity of nanoparticles depend on physicochemical properties of copper oxide nanoparticles and bacterial strain.

  3. Combined role of childhood maltreatment, family history, and gender in the risk for alcohol dependence.

    Science.gov (United States)

    Fenton, M C; Geier, T; Keyes, K; Skodol, A E; Grant, B F; Hasin, D S

    2013-05-01

    Studies of the relationship between childhood maltreatment and alcohol dependence have not controlled comprehensively for potential confounding by co-occurring maltreatments and other childhood trauma, or determined whether parental history of alcohol disorders operates synergistically with gender and maltreatment to produce alcohol dependence. We addressed these issues using national data. Method Face-to-face surveys of 27 712 adult participants in a national survey. Childhood physical, emotional and sexual abuse, and physical neglect were associated with alcohol dependence (prelationships for physical abuse in the entire sample, and for sexual abuse and emotional neglect in women (APs, 0.21, 0.31, 0.26 respectively), indicating that the odds of alcohol dependence given both parental history and these maltreatments were significantly higher than the additive effect of each alone (pdependence. Importantly, results suggest a synergistic role of parental alcoholism: the effect of physical abuse on alcohol dependence may depend on parental history, while the effects of sexual abuse and emotional neglect may depend on parental history among women. Findings underscore the importance of early identification and prevention, particularly among those with a family history, and could guide genetic research and intervention development, e.g. programs to reduce the burden of childhood maltreatment may benefit from addressing the negative long-term effects of maltreatments, including potential alcohol problems, across a broad range of childhood environments.

  4. Life history dependent morphometric variation in stream-dwelling Atlantic salmon

    Science.gov (United States)

    Letcher, B.H.

    2003-01-01

    The time course of morphometric variation among life histories for stream-dwelling Atlantic salmon (Salmo salar L.) parr (age-0+ to age-2+) was analyzed. Possible life histories were combinations of parr maturity status in the autumn (mature or immature) and age at outmigration (smolt at age-2+ or later age). Actual life histories expressed with enough fish for analysis in the 1997 cohort were immature/age-2+ smolt, mature/age-2 +smolt, and mature/age-2+ non-smolt. Tagged fish were assigned to one of the three life histories and digital pictures from the field were analyzed using landmark-based geometric morphometrics. Results indicated that successful grouping of fish according to life history varied with fish age, but that fish could be grouped before the actual expression of the life histories. By March (age-1+), fish were successfully grouped using a descriptive discriminant function and successful assignment ranged from 84 to 97% for the remainder of stream residence. A jackknife of the discriminant function revealed an average life history prediction success of 67% from age-1+ summer to smolting. Low sample numbers for one of the life histories may have limited prediction success. A MANOVA on the shape descriptors (relative warps) also indicated significant differences in shape among life histories from age-1+ summer through to smolting. Across all samples, shape varied significantly with size. Within samples, shape did not vary significantly with size for samples from December (age-0+) to May (age-1+). During the age-1+ summer however, shape varied significantly with size, but the relationship between shape and size was not different among life histories. In the autumn (age-1+) and winter (age-2+), life history differences explained a significant portion of the change in shape with size. Life history dependent morphometric variation may be useful to indicate the timing of early expressions of life history variation and as a tool to explore temporal and

  5. Wavelength dependence of femtosecond laser-induced damage threshold of optical materials

    Energy Technology Data Exchange (ETDEWEB)

    Gallais, L., E-mail: laurent.gallais@fresnel.fr; Douti, D.-B.; Commandré, M. [Aix-Marseille Université, CNRS, Centrale Marseille, Institut Fresnel UMR 7249, 13013 Marseille (France); Batavičiūtė, G.; Pupka, E.; Ščiuka, M.; Smalakys, L.; Sirutkaitis, V.; Melninkaitis, A. [Laser Research Center, Vilnius University, Saulétekio aléja 10, LT-10223 Vilnius (Lithuania)

    2015-06-14

    An experimental and numerical study of the laser-induced damage of the surface of optical material in the femtosecond regime is presented. The objective of this work is to investigate the different processes involved as a function of the ratio of photon to bandgap energies and compare the results to models based on nonlinear ionization processes. Experimentally, the laser-induced damage threshold of optical materials has been studied in a range of wavelengths from 1030 nm (1.2 eV) to 310 nm (4 eV) with pulse durations of 100 fs with the use of an optical parametric amplifier system. Semi-conductors and dielectrics materials, in bulk or thin film forms, in a range of bandgap from 1 to 10 eV have been tested in order to investigate the scaling of the femtosecond laser damage threshold with the bandgap and photon energy. A model based on the Keldysh photo-ionization theory and the description of impact ionization by a multiple-rate-equation system is used to explain the dependence of laser-breakdown with the photon energy. The calculated damage fluence threshold is found to be consistent with experimental results. From these results, the relative importance of the ionization processes can be derived depending on material properties and irradiation conditions. Moreover, the observed damage morphologies can be described within the framework of the model by taking into account the dynamics of energy deposition with one dimensional propagation simulations in the excited material and thermodynamical considerations.

  6. Generation of spectra and stress histories for fatigue and damage tolerance analysis of fuselage repairs

    Science.gov (United States)

    1991-10-01

    This report describes a simplified procedure for the development of stress histories : for use in the analysis of aircraft repairs.- Although repairs of all components of : the airframe are of interest, this report concentrates on stress histories fo...

  7. Electron Beam Irradiation Dose Dependently Damages the Bacillus Spore Coat and Spore Membrane

    Directory of Open Access Journals (Sweden)

    S. E. Fiester

    2012-01-01

    Full Text Available Effective control of spore-forming bacilli begs suitable physical or chemical methods. While many spore inactivation techniques have been proven effective, electron beam (EB irradiation has been frequently chosen to eradicate Bacillus spores. Despite its widespread use, there are limited data evaluating the effects of EB irradiation on Bacillus spores. To study this, B. atrophaeus spores were purified, suspended in sterile, distilled water, and irradiated with EB (up to 20 kGy. Irradiated spores were found (1 to contain structural damage as observed by electron microscopy, (2 to have spilled cytoplasmic contents as measured by spectroscopy, (3 to have reduced membrane integrity as determined by fluorescence cytometry, and (4 to have fragmented genomic DNA as measured by gel electrophoresis, all in a dose-dependent manner. Additionally, cytometry data reveal decreased spore size, increased surface alterations, and increased uptake of propidium iodide, with increasing EB dose, suggesting spore coat alterations with membrane damage, prior to loss of spore viability. The present study suggests that EB irradiation of spores in water results in substantial structural damage of the spore coat and inner membrane, and that, along with DNA fragmentation, results in dose-dependent spore inactivation.

  8. ATM-dependent pathways of chromatin remodelling and oxidative DNA damage responses.

    Science.gov (United States)

    Berger, N Daniel; Stanley, Fintan K T; Moore, Shaun; Goodarzi, Aaron A

    2017-10-05

    Ataxia-telangiectasia mutated (ATM) is a serine/threonine protein kinase with a master regulatory function in the DNA damage response. In this role, ATM commands a complex biochemical network that signals the presence of oxidative DNA damage, including the dangerous DNA double-strand break, and facilitates subsequent repair. Here, we review the current state of knowledge regarding ATM-dependent chromatin remodelling and epigenomic alterations that are required to maintain genomic integrity in the presence of DNA double-strand breaks and/or oxidative stress. We will focus particularly on the roles of ATM in adjusting nucleosome spacing at sites of unresolved DNA double-strand breaks within complex chromatin environments, and the impact of ATM on preserving the health of cells within the mammalian central nervous system.This article is part of the themed issue 'Chromatin modifiers and remodellers in DNA repair and signalling'. © 2017 The Author(s).

  9. A method of modeling time-dependent rock damage surrounding underground excavations in multiphase groundwater flow

    International Nuclear Information System (INIS)

    Christian-Frear, T.; Freeze, G.

    1997-01-01

    Underground excavations produce damaged zones surrounding the excavations which have disturbed hydrologic and geomechanical properties. Prediction of fluid flow in these zones must consider both the mechanical and fluid flow processes. Presented here is a methodology which utilizes a mechanical model to predict damage and disturbed rock zone (DRZ) development around the excavation and then uses the predictions to develop time-dependent DRZ porosity relationships. These relationships are then used to adjust the porosity of the DRZ in the fluid flow model based upon the time and distance from the edge of the excavation. The application of this methodology is presented using a site-specific example from the Waste Isolation Pilot Plant, a US Department of Energy facility in bedded salts being evaluated for demonstration of the safe underground disposal of transuranic waste from US defense-related activities

  10. History-Dependent Problems with Applications to Contact Models for Elastic Beams

    International Nuclear Information System (INIS)

    Bartosz, Krzysztof; Kalita, Piotr; Migórski, Stanisław; Ochal, Anna; Sofonea, Mircea

    2016-01-01

    We prove an existence and uniqueness result for a class of subdifferential inclusions which involve a history-dependent operator. Then we specialize this result in the study of a class of history-dependent hemivariational inequalities. Problems of such kind arise in a large number of mathematical models which describe quasistatic processes of contact. To provide an example we consider an elastic beam in contact with a reactive obstacle. The contact is modeled with a new and nonstandard condition which involves both the subdifferential of a nonconvex and nonsmooth function and a Volterra-type integral term. We derive a variational formulation of the problem which is in the form of a history-dependent hemivariational inequality for the displacement field. Then, we use our abstract result to prove its unique weak solvability. Finally, we consider a numerical approximation of the model, solve effectively the approximate problems and provide numerical simulations

  11. History-Dependent Problems with Applications to Contact Models for Elastic Beams

    Energy Technology Data Exchange (ETDEWEB)

    Bartosz, Krzysztof; Kalita, Piotr; Migórski, Stanisław; Ochal, Anna, E-mail: ochal@ii.uj.edu.pl [Jagiellonian University, Faculty of Mathematics and Computer Science (Poland); Sofonea, Mircea [Université de Perpignan Via Domitia, Laboratoire de Mathématiques et Physique (France)

    2016-02-15

    We prove an existence and uniqueness result for a class of subdifferential inclusions which involve a history-dependent operator. Then we specialize this result in the study of a class of history-dependent hemivariational inequalities. Problems of such kind arise in a large number of mathematical models which describe quasistatic processes of contact. To provide an example we consider an elastic beam in contact with a reactive obstacle. The contact is modeled with a new and nonstandard condition which involves both the subdifferential of a nonconvex and nonsmooth function and a Volterra-type integral term. We derive a variational formulation of the problem which is in the form of a history-dependent hemivariational inequality for the displacement field. Then, we use our abstract result to prove its unique weak solvability. Finally, we consider a numerical approximation of the model, solve effectively the approximate problems and provide numerical simulations.

  12. Damage to lens fiber cells causes TRPV4-dependent Src family kinase activation in the epithelium.

    Science.gov (United States)

    Shahidullah, M; Mandal, A; Delamere, N A

    2015-11-01

    The bulk of the lens consists of tightly packed fiber cells. Because mature lens fibers lack mitochondria and other organelles, lens homeostasis relies on a monolayer of epithelial cells at the anterior surface. The detection of various signaling pathways in lens epithelial cells suggests they respond to stimuli that influence lens function. Focusing on Src Family Kinases (SFKs) and Transient Receptor Potential Vanilloid 4 (TRPV4), we tested whether the epithelium can sense and respond to an event that occurs in fiber mass. The pig lens was subjected to localized freeze-thaw (FT) damage to fibers at posterior pole then the lens was incubated for 1-10 min in Krebs solution at 37 °C. Transient SFK activation in the epithelium was detectable at 1 min. Using a western blot approach, the ion channel TRPV4 was detected in the epithelium but was sparse or absent in fiber cells. Even though TRPV4 expression appears low at the actual site of FT damage to the fibers, SFK activation in the epithelium was suppressed in lenses subjected to FT damage then incubated with the TRPV4 antagonist HC067047 (10 μM). Na,K-ATPase activity was examined because previous studies report changes of Na,K-ATPase activity associated with SFK activation. Na,K-ATPase activity doubled in the epithelium removed from FT-damaged lenses and the response was prevented by HC067047 or the SFK inhibitor PP2 (10 μM). Similar changes were observed in response to fiber damage caused by injection of 5 μl hyperosmotic NaCl or mannitol solution beneath the surface of the posterior pole. The findings point to a TRPV4-dependent mechanism that enables the epithelial cells to detect remote damage in the fiber mass and respond within minutes by activating SFK and increasing Na,K-ATPase activity. Because TRPV4 channels are mechanosensitive, we speculate they may be stimulated by swelling of the lens structure caused by damage to the fibers. Increased Na,K-ATPase activity gives the lens greater capacity to

  13. A Systematic Analysis of Factors Localized to Damaged Chromatin Reveals PARP-Dependent Recruitment of Transcription Factors.

    Science.gov (United States)

    Izhar, Lior; Adamson, Britt; Ciccia, Alberto; Lewis, Jedd; Pontano-Vaites, Laura; Leng, Yumei; Liang, Anthony C; Westbrook, Thomas F; Harper, J Wade; Elledge, Stephen J

    2015-06-09

    Localization to sites of DNA damage is a hallmark of DNA damage response (DDR) proteins. To identify DDR factors, we screened epitope-tagged proteins for localization to sites of chromatin damaged by UV laser microirradiation and found >120 proteins that localize to damaged chromatin. These include the BAF tumor suppressor complex and the amyotrophic lateral sclerosis (ALS) candidate protein TAF15. TAF15 contains multiple domains that bind damaged chromatin in a poly-(ADP-ribose) polymerase (PARP)-dependent manner, suggesting a possible role as glue that tethers multiple PAR chains together. Many positives were transcription factors; > 70% of randomly tested transcription factors localized to sites of DNA damage, and of these, ∼90% were PARP dependent for localization. Mutational analyses showed that localization to damaged chromatin is DNA-binding-domain dependent. By examining Hoechst staining patterns at damage sites, we see evidence of chromatin decompaction that is PARP dependent. We propose that PARP-regulated chromatin remodeling at sites of damage allows transient accessibility of DNA-binding proteins. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  14. A Systematic Analysis of Factors Localized to Damaged Chromatin Reveals PARP-Dependent Recruitment of Transcription Factors

    Directory of Open Access Journals (Sweden)

    Lior Izhar

    2015-06-01

    Full Text Available Localization to sites of DNA damage is a hallmark of DNA damage response (DDR proteins. To identify DDR factors, we screened epitope-tagged proteins for localization to sites of chromatin damaged by UV laser microirradiation and found >120 proteins that localize to damaged chromatin. These include the BAF tumor suppressor complex and the amyotrophic lateral sclerosis (ALS candidate protein TAF15. TAF15 contains multiple domains that bind damaged chromatin in a poly-(ADP-ribose polymerase (PARP-dependent manner, suggesting a possible role as glue that tethers multiple PAR chains together. Many positives were transcription factors; > 70% of randomly tested transcription factors localized to sites of DNA damage, and of these, ∼90% were PARP dependent for localization. Mutational analyses showed that localization to damaged chromatin is DNA-binding-domain dependent. By examining Hoechst staining patterns at damage sites, we see evidence of chromatin decompaction that is PARP dependent. We propose that PARP-regulated chromatin remodeling at sites of damage allows transient accessibility of DNA-binding proteins.

  15. The effect of ancient DNA damage on inferences of demographic histories

    DEFF Research Database (Denmark)

    Axelsson, Erik; Willerslev, Eske; Gilbert, Marcus Thomas Pius

    2008-01-01

    The field of ancient DNA (aDNA) is casting new light on many evolutionary questions. However, problems associated with the postmortem instability of DNA may complicate the interpretation of aDNA data. For example, in population genetic studies, the inclusion of damaged DNA may inflate estimates o...... for a change in effective population size in this data set vanishes once the effects of putative damage are removed. Our results suggest that population genetic analyses of aDNA sequences, which do not accurately account for damage, should be interpreted with great caution....

  16. A new differential equations-based model for nonlinear history-dependent magnetic behaviour

    International Nuclear Information System (INIS)

    Aktaa, J.; Weth, A. von der

    2000-01-01

    The paper presents a new kind of numerical model describing nonlinear magnetic behaviour. The model is formulated as a set of differential equations taking into account history dependence phenomena like the magnetisation hysteresis as well as saturation effects. The capability of the model is demonstrated carrying out comparisons between measurements and calculations

  17. Time-adaptive and history-adaptive multicriterion routing in stochastic, time-dependent networks

    DEFF Research Database (Denmark)

    Pretolani, Daniele; Nielsen, Lars Relund; Andersen, Kim Allan

    2009-01-01

    We compare two different models for multicriterion routing in stochastic time-dependent networks: the classic "time-adaptive'' model and the more flexible "history-adaptive'' one. We point out several properties of the sets of efficient solutions found under the two models. We also devise a method...

  18. Cellular defense against singlet oxygen-induced oxidative damage by cytosolic NADP+-dependent isocitrate dehydrogenase.

    Science.gov (United States)

    Kim, Sun Yee; Park, Jeen-Woo

    2003-03-01

    Singlet oxygen (1O2) is a highly reactive form of molecular oxygen that may harm living systems by oxidizing critical cellular macromolecules. Recently, we have shown that NADP+-dependent isocitrate dehydrogenase is involved in the supply of NADPH needed for GSH production against cellular oxidative damage. In this study, we investigated the role of cytosolic form of NADP+-dependent isocitrate dehydrogenase (IDPc) against singlet oxygen-induced cytotoxicity by comparing the relative degree of cellular responses in three different NIH3T3 cells with stable transfection with the cDNA for mouse IDPc in sense and antisense orientations, where IDPc activities were 2.3-fold higher and 39% lower, respectively, than that in the parental cells carrying the vector alone. Upon exposure to singlet oxygen generated from photoactivated dye, the cells with low levels of IDPc became more sensitive to cell killing. Lipid peroxidation, protein oxidation, oxidative DNA damage and intracellular peroxide generation were higher in the cell-line expressing the lower level of IDPc. However, the cells with the highly over-expressed IDPc exhibited enhanced resistance against singlet oxygen, compared to the control cells. The data indicate that IDPc plays an important role in cellular defense against singlet oxygen-induced oxidative injury.

  19. History-dependent friction and slow slip from time-dependent microscopic junction laws studied in a statistical framework.

    Science.gov (United States)

    Thøgersen, Kjetil; Trømborg, Jørgen Kjoshagen; Sveinsson, Henrik Andersen; Malthe-Sørenssen, Anders; Scheibert, Julien

    2014-05-01

    To study how macroscopic friction phenomena originate from microscopic junction laws, we introduce a general statistical framework describing the collective behavior of a large number of individual microjunctions forming a macroscopic frictional interface. Each microjunction can switch in time between two states: a pinned state characterized by a displacement-dependent force and a slipping state characterized by a time-dependent force. Instead of tracking each microjunction individually, the state of the interface is described by two coupled distributions for (i) the stretching of pinned junctions and (ii) the time spent in the slipping state. This framework allows for a whole family of microjunction behavior laws, and we show how it represents an overarching structure for many existing models found in the friction literature. We then use this framework to pinpoint the effects of the time scale that controls the duration of the slipping state. First, we show that the model reproduces a series of friction phenomena already observed experimentally. The macroscopic steady-state friction force is velocity dependent, either monotonic (strengthening or weakening) or nonmonotonic (weakening-strengthening), depending on the microscopic behavior of individual junctions. In addition, slow slip, which has been reported in a wide variety of systems, spontaneously occurs in the model if the friction contribution from junctions in the slipping state is time weakening. Next, we show that the model predicts a nontrivial history dependence of the macroscopic static friction force. In particular, the static friction coefficient at the onset of sliding is shown to increase with increasing deceleration during the final phases of the preceding sliding event. We suggest that this form of history dependence of static friction should be investigated in experiments, and we provide the acceleration range in which this effect is expected to be experimentally observable.

  20. Climate change adaptation, damages and fossil fuel dependence. An RETD position paper on the costs of inaction

    Energy Technology Data Exchange (ETDEWEB)

    Katofsky, Ryan; Stanberry, Matt; Hagenstad, Marca; Frantzis, Lisa

    2011-07-15

    The Renewable Energy Technology Deployment (RETD) agreement initiated this project to advance the understanding of the ''Costs of Inaction'', i.e. the costs of climate change adaptation, damages and fossil fuel dependence. A quantitative estimate was developed as well as a better understanding of the knowledge gaps and research needs. The project also included some conceptual work on how to better integrate the analyses of mitigation, adaptation, damages and fossil fuel dependence in energy scenario modelling.

  1. Dependence of the critical current density on the history of magnetic field and temperature

    International Nuclear Information System (INIS)

    Kuepfer, H.

    1976-08-01

    The dependence of the volume pinning force on different paths taken to arrive at a state (H,T) is investigated. The local magnetic induction is measured by means of an ac technique on samples with different Hsub(c), kappa, pinning centres and densities. Line pinning and a distorted flux line lattice are properties of those samples which show the above mentioned history dependence. Using the model of E.J. Kramer it is deduced the reason of the history effect is the dependence of the shear modulus on the defect structure of the flux line lattice. The differences occur in the lower field region and are also observed in materials with kappa approximately = 40 and large volume pinning forces. (orig.) [de

  2. Surface structural damage associated with longwall mining near Tuscaloosa, Alabama: a case history

    International Nuclear Information System (INIS)

    Isphording, W.C.

    1992-01-01

    Initially the paper examines the frequency of coal mine subsidence and the influence on surface subsidence of subsurface mining methods, i.e. room and pillar and longwall mining. A case study of the subsidence damage caused to a log house near Tuscaloosa, Alabama (USA), when a longwall panel passed beneath it is presented. The damage resulted in the homeowners suing the mining company for negligence. The article discusses information provided to the plaintiffs attorneys by the author. Aspects covered are: the subsidence and damage to the property; prediction of subsidence; the monitoring of subsidence; and the prevention of subsidence. An out-of-court settlement was agreed by the two parties. 15 refs., 5 figs

  3. Cytosolic NADP(+)-dependent isocitrate dehydrogenase status modulates oxidative damage to cells.

    Science.gov (United States)

    Lee, Su Min; Koh, Ho-Jin; Park, Dong-Chan; Song, Byoung J; Huh, Tae-Lin; Park, Jeen-Woo

    2002-06-01

    NADPH is an important cofactor in many biosynthesis pathways and the regeneration of reduced glutathione, critically important in cellular defense against oxidative damage. It is mainly produced by glucose 6-phosphate dehydrogenase (G6PD), malic enzyme, and the cytosolic form of NADP(+)-dependent isocitrate dehydrogenase (IDPc). Little information is available about the role of IDPc in antioxidant defense. In this study we investigated the role of IDPc against cytotoxicity induced by oxidative stress by comparing the relative degree of cellular responses in three different NIH3T3 cells with stable transfection with the cDNA for mouse IDPc in sense and antisense orientations, where IDPc activities were 3-4-fold higher and 35% lower, respectively, than that in the parental cells carrying the vector alone. Although the activities of other antioxidant enzymes, such as superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase, and G6PD, were comparable in all transformed cells, the ratio of GSSG to total glutathione was significantly higher in the cells expressing the lower level of IDPc. This finding indicates that IDPc is essential for the efficient glutathione recycling. Upon transient exposure to increasing concentrations of H(2)O(2) or menadione, an intracellular source of free radicals and reactive oxygen species, the cells with low levels of IDPc became more sensitive to oxidative damage by H(2)O(2) or menadione. Lipid peroxidation, oxidative DNA damage, and intracellular peroxide generation were higher in the cell-line expressing the lower level of IDPc. However, the cells with the highly over-expressed IDPc exhibited enhanced resistance against oxidative stress, compared to the control cells. This study provides direct evidence correlating the activities of IDPc and the maintenance of the cellular redox state, suggesting that IDPc plays an important role in cellular defense against oxidative stress.

  4. A family of metal-dependent phosphatases implicated in metabolite damage-control

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Lili; Khusnutdinova, Anna; Nocek, Boguslaw; Brown, Greg; Xu, Xiaohui; Cui, Hong; Petit, Pierre; Flick, Robert; Zallot, Rémi; Balmant, Kelly; Ziemak, Michael J.; Shanklin, John; de Crécy-Lagard, Valérie; Fiehn, Oliver; Gregory, Jesse F.; Joachimiak, Andrzej; Savchenko, Alexei; Yakunin, Alexander F.; Hanson, Andrew D.

    2016-06-20

    DUF89 family proteins occur widely in both prokaryotes and eukaryotes, but their functions are unknown. Here we define three DUF89 subfamilies (I, II, and III), with subfamily II being split into stand-alone proteins and proteins fused to pantothenate kinase (PanK). We demonstrated that DUF89 proteins have metal-dependent phosphatase activity against reactive phosphoesters or their damaged forms, notably sugar phosphates (subfamilies II and III), phosphopantetheine and its S-sulfonate or sulfonate (subfamily II-PanK fusions), and nucleotides (subfamily I). Genetic and comparative genomic data strongly associated DUF89 genes with phosphoester metabolism. The crystal structure of the yeast (Saccharomyces cerevisiae) subfamily III protein YMR027W revealed a novel phosphatase active site with fructose 6-phosphate and Mg2+ bound near conserved signature residues Asp254 and Asn255 that are critical for activity. These findings indicate that DUF89 proteins are previously unrecognized hydrolases whose characteristic in vivo function is to limit potentially harmful buildups of normal or damaged phosphometabolites.

  5. Post-irradiation modification of oxygen-dependent and independent damage by catalase in barley seeds

    International Nuclear Information System (INIS)

    Sah, N.K.; Kesavan, P.C.

    1987-01-01

    If H 2 O 2 is one of the major mediators of the 'oxygen effect' in biological systems then catalase, which enzymically decomposes H 2 O 2 should have a significant influence on radiation damage, particularly under oxygenated conditions. The post-irradiation (300 Gy gamma rays) effect of catalase was, therefore, assessed on barley seeds of about 4% moisture content under oxygenated and oxygen-free conditions at varying temperatures. Catalase affords concentration-dependent radioprotection under oxygenated condition at both 25 0 C and 4 0 C. The level of protection at 4 0 C is less than at 25 0 C. This is obviously due to a decrease in catalase activity at low temperature. Under oxygen-free conditions, catalase enhances radiation damage at 4 0 C while at 25 0 C it it has no effect. This has been substantiated by data on the frequency of chromosomal aberrations and on peroxidase activity. Sodium azide, a catalase inhibitor, was found to eliminate the radioprotective action of catalase. The study supports the view that the 'oxygen effect' is mediated largely through peroxides in irradiated biological systems. However, the observations made particularly at 4 0 C under oxygen-free condition seem to involve physicochemical reactions. (author)

  6. Thermal Skin Damage During Reirradiation and Hyperthermia Is Time-Temperature Dependent

    Energy Technology Data Exchange (ETDEWEB)

    Bakker, Akke, E-mail: akke.bakker@amc.uva.nl [Department of Radiation Oncology, Academic Medical Center (AMC), Amsterdam (Netherlands); Kolff, M. Willemijn [Department of Radiation Oncology, Academic Medical Center (AMC), Amsterdam (Netherlands); Holman, Rebecca [Clinical Research Unit, Academic Medical Center (AMC), Amsterdam (Netherlands); Leeuwen, Caspar M. van; Korshuize-van Straten, Linda; Kroon-Oldenhof, Rianne de; Rasch, Coen R.N.; Tienhoven, Geertjan van; Crezee, Hans [Department of Radiation Oncology, Academic Medical Center (AMC), Amsterdam (Netherlands)

    2017-06-01

    Purpose: To investigate the relationship of thermal skin damage (TSD) to time–temperature isoeffect levels for patients with breast cancer recurrence treated with reirradiation plus hyperthermia (reRT + HT), and to investigate whether the treatment history of previous treatments (scar tissue) is a risk factor for TSD. Methods and Materials: In this observational study, temperature characteristics of hyperthermia sessions were analyzed in 262 patients with recurrent breast cancer treated in the AMC between 2010 and 2014 with reirradiation and weekly hyperthermia for 1 hour. Skin temperature was measured using a median of 42 (range, 29-82) measurement points per hyperthermia session. Results: Sixty-eight patients (26%) developed 79 sites of TSD, after the first (n=26), second (n=17), third (n=27), and fourth (n=9) hyperthermia session. Seventy percent of TSD occurred on or near scar tissue. Scar tissue reached higher temperatures than other skin tissue (0.4°C, P<.001). A total of 102 measurement points corresponded to actual TSD sites in 35 of 79 sessions in which TSD developed. Thermal skin damage sites had much higher maximum temperatures than non-TSD sites (2.8°C, P<.001). Generalized linear mixed models showed that the probability of TSD is related to temperature and thermal dose values (P<.001) and that scar tissue is more at risk (odds ratio 0.4, P<.001). Limiting the maximum temperature of a measurement point to 43.7°C would mean that the probability of observing TSD was at most 5%. Conclusion: Thermal skin damage during reRT + HT for recurrent breast cancer was related to higher local temperatures and time–temperature isoeffect levels. Scar tissue reached higher temperatures than other skin tissue, and TSD occurred at lower temperatures and thermal dose values in scar tissue compared with other skin tissue. Indeed, TSD developed often on and around scar tissue from previous surgical procedures.

  7. Mapping DNA damage-dependent genetic interactions in yeast via party mating and barcode fusion genetics.

    Science.gov (United States)

    Díaz-Mejía, J Javier; Celaj, Albi; Mellor, Joseph C; Coté, Atina; Balint, Attila; Ho, Brandon; Bansal, Pritpal; Shaeri, Fatemeh; Gebbia, Marinella; Weile, Jochen; Verby, Marta; Karkhanina, Anna; Zhang, YiFan; Wong, Cassandra; Rich, Justin; Prendergast, D'Arcy; Gupta, Gaurav; Öztürk, Sedide; Durocher, Daniel; Brown, Grant W; Roth, Frederick P

    2018-05-28

    Condition-dependent genetic interactions can reveal functional relationships between genes that are not evident under standard culture conditions. State-of-the-art yeast genetic interaction mapping, which relies on robotic manipulation of arrays of double-mutant strains, does not scale readily to multi-condition studies. Here, we describe barcode fusion genetics to map genetic interactions (BFG-GI), by which double-mutant strains generated via en masse "party" mating can also be monitored en masse for growth to detect genetic interactions. By using site-specific recombination to fuse two DNA barcodes, each representing a specific gene deletion, BFG-GI enables multiplexed quantitative tracking of double mutants via next-generation sequencing. We applied BFG-GI to a matrix of DNA repair genes under nine different conditions, including methyl methanesulfonate (MMS), 4-nitroquinoline 1-oxide (4NQO), bleomycin, zeocin, and three other DNA-damaging environments. BFG-GI recapitulated known genetic interactions and yielded new condition-dependent genetic interactions. We validated and further explored a subnetwork of condition-dependent genetic interactions involving MAG1 , SLX4, and genes encoding the Shu complex, and inferred that loss of the Shu complex leads to an increase in the activation of the checkpoint protein kinase Rad53. © 2018 The Authors. Published under the terms of the CC BY 4.0 license.

  8. p18(Hamlet) mediates different p53-dependent responses to DNA-damage inducing agents.

    Science.gov (United States)

    Lafarga, Vanesa; Cuadrado, Ana; Nebreda, Angel R

    2007-10-01

    Cells organize appropriate responses to environmental cues by activating specific signaling networks. Two proteins that play key roles in coordinating stress responses are the kinase p38alpha (MAPK14) and the transcription factor p53 (TP53). Depending on the nature and the extent of the stress-induced damage, cells may respond by arresting the cell cycle or by undergoing cell death, and these responses are usually associated with the phosphorylation of particular substrates by p38alpha as well as the activation of specific target genes by p53. We recently characterized a new p38alpha substrate, named p18(Hamlet) (ZNHIT1), which mediates p53-dependent responses to different genotoxic stresses. Thus, cisplatin or UV light induce stabilization of the p18(Hamlet) protein, which then enhances the ability of p53 to bind to and activate the promoters of pro-apoptotic genes such as NOXA and PUMA leading to apoptosis induction. In a similar way, we report here that p18(Hamlet) can also mediate the cell cycle arrest induced in response to gamma-irradiation, by participating in the p53-dependent upregulation of the cell cycle inhibitor p21(Cip1) (CDKN1A).

  9. Mono and sequential ion irradiation induced damage formation and damage recovery in oxide glasses: Stopping power dependence of the mechanical properties

    International Nuclear Information System (INIS)

    Mir, A.H.; Monnet, I.; Toulemonde, M.; Bouffard, S.; Jegou, C.; Peuget, S.

    2016-01-01

    Simple and complex borosilicate glasses were irradiated with single and double ion beams of light and heavy ions over a broad fluence and stopping power range. As a result of the heavy ion irradiation (U, Kr, Au), the hardness was observed to diminish and saturate after a decrease by 35 ± 1%. Unlike slow and swift heavy ion irradiation, irradiation with light ions (He,O) induced a saturation hardness decrease of 18 ± 1% only. During double ion beam irradiation; where glasses were first irradiated with a heavy ion (gold) and then by a light ion (helium), the light ion irradiation induced partial damage recovery. As a consequence of the recovery effect, the hardness of the pre-irradiated glasses increased by 10–15% depending on the chemical composition. These results highlight that the nuclear energy loss and high electronic energy loss (≥4 keV/nm) result in significant and similar modifications whereas light ions with low electronic energy loss (≤1 keV/nm) result in only mild damage formation in virgin glasses and recovery in highly pre-damaged glasses. These results are important to understand the damage formation and recovery in actinide bearing minerals and in glasses subjected to self-irradiation by alpha decays. - Highlights: • Behavior of glasses strongly depends on the electronic energy loss (Se) of the ions. • High Se (≥4 keV/nm) induces large changes in comparison to lower Se values. • Apart from mild damage formation, low Se causes recovery of pre-existing damage. • Alpha induced partial recovery of the damage would occur in nuclear waste glasses.

  10. Properly quantized history-dependent Parrondo games, Markov processes, and multiplexing circuits

    Energy Technology Data Exchange (ETDEWEB)

    Bleiler, Steven A. [Fariborz Maseeh Department of Mathematics and Statistics, Portland State University, PO Box 751, Portland, OR 97207 (United States); Khan, Faisal Shah, E-mail: faisal.khan@kustar.ac.a [Khalifa University of Science, Technology and Research, PO Box 127788, Abu Dhabi (United Arab Emirates)

    2011-05-09

    Highlights: History-dependent Parrondo games are viewed as Markov processes. Quantum mechanical analogues of these Markov processes are constructed. These quantum analogues restrict to the original process on measurement. Relationship between these analogues and a quantum circuits is exhibited. - Abstract: In the context of quantum information theory, 'quantization' of various mathematical and computational constructions is said to occur upon the replacement, at various points in the construction, of the classical randomization notion of probability distribution with higher order randomization notions from quantum mechanics such as quantum superposition with measurement. For this to be done 'properly', a faithful copy of the original construction is required to exist within the new quantum one, just as is required when a function is extended to a larger domain. Here procedures for extending history-dependent Parrondo games, Markov processes and multiplexing circuits to their quantum versions are analyzed from a game theoretic viewpoint, and from this viewpoint, proper quantizations developed.

  11. Associations between behavioral disinhibition and cocaine use history in individuals with cocaine dependence.

    Science.gov (United States)

    Prisciandaro, James J; Korte, Jeffrey E; McRae-Clark, Aimee L; Brady, Kathleen T

    2012-10-01

    Behavioral disinhibition has been suggested as both a cause and consequence of substance use disorders. Many studies examining associations between behavioral disinhibition and substance use history have focused on individuals with alcohol dependence or non-dependent college students. In the present study, the relationship between behavioral disinhibition and cocaine use history in individuals with cocaine dependence is examined. Forty-six non-treatment-seeking cocaine-dependent men and women completed impulsivity (Barratt impulsiveness scale; BIS) and novelty seeking (temperament and character inventory; TCI) questionnaires at the baseline visit of an ongoing study. Unadjusted, and adjusted for gender and age, Pearson correlations were calculated between BIS, TCI, and cocaine use variables from the structured clinical interview for DSM-IV and timeline follow-back (age of onset, quantity/frequency of past 30 day cocaine use). As expected, elevated motor impulsivity and novelty seeking were each associated with younger age of dependence onset. Also, individuals with lower levels of persistence on the TCI reported more days of cocaine use over the previous month. Unexpectedly, increased novelty seeking and attentional impulsivity were associated with fewer days of cocaine use and less money spent on cocaine, respectively. Controlling for age and gender did not substantially change the pattern of observed associations. The present study provides preliminary evidence for associations between behavioral disinhibition and cocaine use history in cocaine-dependent individuals. Given our relatively small sample size and the correlational nature of our findings, further research is needed to replicate and extend our results. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. History-dependent excitability as a single-cell substrate of transient memory for information discrimination.

    Directory of Open Access Journals (Sweden)

    Fabiano Baroni

    Full Text Available Neurons react differently to incoming stimuli depending upon their previous history of stimulation. This property can be considered as a single-cell substrate for transient memory, or context-dependent information processing: depending upon the current context that the neuron "sees" through the subset of the network impinging on it in the immediate past, the same synaptic event can evoke a postsynaptic spike or just a subthreshold depolarization. We propose a formal definition of History-Dependent Excitability (HDE as a measure of the propensity to firing in any moment in time, linking the subthreshold history-dependent dynamics with spike generation. This definition allows the quantitative assessment of the intrinsic memory for different single-neuron dynamics and input statistics. We illustrate the concept of HDE by considering two general dynamical mechanisms: the passive behavior of an Integrate and Fire (IF neuron, and the inductive behavior of a Generalized Integrate and Fire (GIF neuron with subthreshold damped oscillations. This framework allows us to characterize the sensitivity of different model neurons to the detailed temporal structure of incoming stimuli. While a neuron with intrinsic oscillations discriminates equally well between input trains with the same or different frequency, a passive neuron discriminates better between inputs with different frequencies. This suggests that passive neurons are better suited to rate-based computation, while neurons with subthreshold oscillations are advantageous in a temporal coding scheme. We also address the influence of intrinsic properties in single-cell processing as a function of input statistics, and show that intrinsic oscillations enhance discrimination sensitivity at high input rates. Finally, we discuss how the recognition of these cell-specific discrimination properties might further our understanding of neuronal network computations and their relationships to the distribution and

  13. Memory in microbes: quantifying history-dependent behavior in a bacterium.

    Directory of Open Access Journals (Sweden)

    Denise M Wolf

    2008-02-01

    Full Text Available Memory is usually associated with higher organisms rather than bacteria. However, evidence is mounting that many regulatory networks within bacteria are capable of complex dynamics and multi-stable behaviors that have been linked to memory in other systems. Moreover, it is recognized that bacteria that have experienced different environmental histories may respond differently to current conditions. These "memory" effects may be more than incidental to the regulatory mechanisms controlling acclimation or to the status of the metabolic stores. Rather, they may be regulated by the cell and confer fitness to the organism in the evolutionary game it participates in. Here, we propose that history-dependent behavior is a potentially important manifestation of memory, worth classifying and quantifying. To this end, we develop an information-theory based conceptual framework for measuring both the persistence of memory in microbes and the amount of information about the past encoded in history-dependent dynamics. This method produces a phenomenological measure of cellular memory without regard to the specific cellular mechanisms encoding it. We then apply this framework to a strain of Bacillus subtilis engineered to report on commitment to sporulation and degradative enzyme (AprE synthesis and estimate the capacity of these systems and growth dynamics to 'remember' 10 distinct cell histories prior to application of a common stressor. The analysis suggests that B. subtilis remembers, both in short and long term, aspects of its cell history, and that this memory is distributed differently among the observables. While this study does not examine the mechanistic bases for memory, it presents a framework for quantifying memory in cellular behaviors and is thus a starting point for studying new questions about cellular regulation and evolutionary strategy.

  14. Transgenerational plasticity in the sea: context-dependent maternal effects across the life history.

    Science.gov (United States)

    Marshall, Dustin J

    2008-02-01

    Maternal effects can have dramatic influences on the phenotype of offspring. Maternal effects can act as a conduit by which the maternal environment negatively affects offspring fitness, but they can also buffer offspring from environmental change by altering the phenotype of offspring according to local environmental conditions and as such, are a form of transgenerational plasticity. The benefits of maternal effects can be highly context dependent, increasing performance in one life-history stage but reducing it in another. While maternal effects are increasingly well understood in terrestrial systems, studies in the marine environment are typically restricted to a single, early life-history stage. Here, I examine the role of maternal effects across the life history of the bryozoan Bugula neritina. I exposed maternal colonies to a common pollution stress (copper) in the laboratory and then placed them in the field for one week to brood offspring. I then examined the resistance of offspring to copper from toxicant-exposed and toxicant-naïve mothers and found that offspring from toxicant-exposed mothers were larger, more dispersive, and more resistant to copper stress than offspring from naïve mothers. However, maternal exposure history had pervasive, negative effects on the post-metamorphic performance (particularly survival) of offspring: offspring from toxicant-exposed mothers had poorer performance after six weeks in the field, especially when facing high levels of intraspecific competition. Maternal experience can have complex effects on offspring phenotype, enhancing performance in one life-history stage while decreasing performance in another. The context-dependent costs and benefits associated with maternally derived pollution resistance may account for why such resistance is induced rather than continually expressed: mothers must balance the benefits of producing pollution-resistant larvae with the costs of producing poorer performing adults (in the

  15. Memory in microbes: quantifying history-Dependent behavior in a bacterium.

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Denise M.; Fontaine-Bodin, Lisa; Bischofs, Ilka; Price, Gavin; Keaslin, Jay; Arkin, Adam P.

    2007-11-15

    Memory is usually associated with higher organisms rather than bacteria. However, evidence is mounting that many regulatory networks within bacteria are capable of complex dynamics and multi-stable behaviors that have been linked to memory in other systems. Moreover, it is recognized that bacteria that have experienced different environmental histories may respond differently to current conditions. These"memory" effects may be more than incidental to the regulatory mechanisms controlling acclimation or to the status of the metabolic stores. Rather, they may be regulated by the cell and confer fitness to the organism in the evolutionary game it participates in. Here, we propose that history-dependent behavior is a potentially important manifestation of memory, worth classifying and quantifying. To this end, we develop an information-theory based conceptual framework for measuring both the persistence of memory in microbes and the amount of information about the past encoded in history-dependent dynamics. This method produces a phenomenological measure of cellular memory without regard to the specific cellular mechanisms encoding it. We then apply this framework to a strain of Bacillus subtilis engineered to report on commitment to sporulation and degradative enzyme (AprE) synthesis and estimate the capacity of these systems and growth dynamics to 'remember' 10 distinct cell histories prior to application of a common stressor. The analysis suggests that B. subtilis remembers, both in short and long term, aspects of its cell history, and that this memory is distributed differently among the observables. While this study does not examine the mechanistic bases for memory, it presents a framework for quantifying memory in cellular behaviors and is thus a starting point for studying new questions about cellular regulation and evolutionary strategy.

  16. A 3D Orthotropic Strain-Rate Dependent Elastic Damage Material Model.

    Energy Technology Data Exchange (ETDEWEB)

    English, Shawn Allen

    2014-09-01

    A three dimensional orthotropic elastic constitutive model with continuum damage and cohesive based fracture is implemented for a general polymer matrix composite lamina. The formulation assumes the possibility of distributed (continuum) damage followed b y localized damage. The current damage activation functions are simply partially interactive quadratic strain criteria . However, the code structure allows for changes in the functions without extraordinary effort. The material model formulation, implementation, characterization and use cases are presented.

  17. rad-Dependent response of the chk1-encoded protein kinase at the DNA damage checkpoint

    NARCIS (Netherlands)

    Walworth, N.C.; Bernards, R.A.

    1996-01-01

    Exposure of eukaryotic cells to agents that generate DNA damage results in transient arrest of progression through the cell cycle. In fission yeast, the DNA damage checkpoint associated with cell cycle arrest before mitosis requires the protein kinase p56chk1. DNA damage induced by ultraviolet

  18. Microbeam Radiation-Induced Tissue Damage Depends on the Stage of Vascular Maturation

    International Nuclear Information System (INIS)

    Sabatasso, Sara; Laissue, Jean Albert; Hlushchuk, Ruslan; Graber, Werner; Bravin, Alberto; Braeuer-Krisch, Elke; Corde, Stephanie; Blattmann, Hans; Gruber, Guenther; Djonov, Valentin

    2011-01-01

    Purpose: To explore the effects of microbeam radiation (MR) on vascular biology, we used the chick chorioallantoic membrane (CAM) model of an almost pure vascular system with immature vessels (lacking periendothelial coverage) at Day 8 and mature vessels (with coverage) at Day 12 of development. Methods and Materials: CAMs were irradiated with microplanar beams (width, ∼25 μm; interbeam spacing, ∼200 μm) at entrance doses of 200 or 300 Gy and, for comparison, with a broad beam (seamless radiation [SLR]), with entrance doses of 5 to 40 Gy. Results: In vivo monitoring of Day-8 CAM vasculature 6 h after 200 Gy MR revealed a near total destruction of the immature capillary plexus. Conversely, 200 Gy MR barely affected Day-12 CAM mature microvasculature. Morphological evaluation of Day-12 CAMs after the dose was increased to 300 Gy revealed opened interendothelial junctions, which could explain the transient mesenchymal edema immediately after irradiation. Electron micrographs revealed cytoplasmic vacuolization of endothelial cells in the beam path, with disrupted luminal surfaces; often the lumen was engorged with erythrocytes and leukocytes. After 30 min, the capillary plexus adopted a striated metronomic pattern, with alternating destroyed and intact zones, corresponding to the beam and the interbeam paths within the array. SLR at a dose of 10 Gy caused growth retardation, resulting in a remarkable reduction in the vascular endpoint density 24 h postirradiation. A dose of 40 Gy damaged the entire CAM vasculature. Conclusions: The effects of MR are mediated by capillary damage, with tissue injury caused by insufficient blood supply. Vascular toxicity and physiological effects of MR depend on the stage of capillary maturation and appear in the first 15 to 60 min after irradiation. Conversely, the effects of SLR, due to the arrest of cell proliferation, persist for a longer time.

  19. DEPENDENCIES TO DETERMINE THE MEASURE OF DAMAGE AND CALCULATION OF RESIDUAL LIFE OF REINFORCED CONCRETE SUPERSTRUCTURE, EXPOSED TO SALT CORROSION

    OpenAIRE

    SAATOVA NODIRA ZIYAYEVNA

    2016-01-01

    In this paper we consider the current method of determining the measure of damage of concrete and reinforcement. The proposed dependence measures of damage, convenient for use in predicting the life of structures superstructures.The practical method of calculation determination of residual resource of the exploited superstructures developed. The main source of data for calculating the residual life are the parameters defined by the technical diagnosis.

  20. History-dependent nonlinear dissipation in superfluid 3He-A

    International Nuclear Information System (INIS)

    Gay, R.; Bagley, M.; Hook, J.R.; Sandiford, D.J.; Hall, H.E.

    1983-01-01

    We have studied nonlinear dissipation in oscillatory flow of 3 He-A through 49-μm- and 17-μm-wide channels by means of torsion pendulum experiments at about 50 Hz. The observed effects are strongly history dependent; the dissipation at a given measuring amplitude is strongly increased if the sample is cooled through T/sub c/ while oscillating at large amplitude. Once a highly dissipative state has been created it does not noticeably decay below T/sub c/, though a more dissipative state can be created below T/sub c/ by a period of sufficiently large-amplitude oscillation. The results are described semiquantitatively by a model based on the idea of superflow collapse by motion of the l vector, with consequent orbital dissipation. The history dependence is introduced into this model by postulating the existence of surface singularities in the l texture, the density of which is determined by the previous history of the helium

  1. Age-dependent male mating tactics in a spider mite-A life-history perspective.

    Science.gov (United States)

    Sato, Yukie; Rühr, Peter T; Schmitz, Helmut; Egas, Martijn; Blanke, Alexander

    2016-10-01

    Males often fight with rival males for access to females. However, some males display nonfighting tactics such as sneaking, satellite behavior, or female mimicking. When these mating tactics comprise a conditional strategy, they are often thought to be explained by resource holding potential (RHP), that is, nonfighting tactics are displayed by less competitive males who are more likely to lose a fight. The alternative mating tactics, however, can also be explained by life-history theory, which predicts that young males avoid fighting, regardless of their RHP, if it pays off to wait for future reproduction. Here, we test whether the sneaking tactic displayed by young males of the two-spotted spider mite can be explained by life-history theory. We tested whether young sneaker males survive longer than young fighter males after a bout of mild or strong competition with old fighter males. We also investigated whether old males have a more protective outer skin-a possible proxy for RHP-by measuring cuticle hardness and elasticity using nanoindentation. We found that young sneaker males survived longer than young fighter males after mild male competition. This difference was not found after strong male competition, which suggests that induction of sneaking tactic is affected by male density. Hardness and elasticity of the skin did not vary with male age. Given that earlier work could also not detect morphometric differences between fighter and sneaker males, we conclude that there is no apparent increase in RHP with age in the mite and age-dependent male mating tactics in the mite can be explained only by life-history theory. Because it is likely that fighting incurs a survival cost, age-dependent alternative mating tactics may be explained by life-history theory in many species when reproduction of old males is a significant factor in fitness.

  2. Memory in Microbes: Quantifying History-Dependent Behavior in a Bacterium

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Denise M.; Fontaine-Bodin, Lisa; Bischofs, Ilka; Price, Gavin; Keasling, Jay; Arkin, Adam P.

    2007-11-15

    Memory is usually associated with higher organisms rather than bacteria. However, evidence is mounting that many regulatory networks within bacteria are capable of complex dynamics and multi-stable behaviors that have been linked to memory in other systems. Moreover, it is recognized that bacteria that have experienced different environmental histories may respond differently to current conditions. These"memory" effects may be more than incidental to the regulatory mechanisms controlling acclimation or to the status of the metabolic stores. Rather, they may be regulated by the cell and confer fitness to the organism in the evolutionary game it participates in. Here, we propose that history-dependent behavior is a potentially important manifestation of memory, worth classifying and quantifying. To this end, we develop an information-theory based conceptual framework for measuring both the persistence of memory in microbes and the amount of information about the past encoded in history-dependent dynamics. This method produces a phenomenologicalmeasure of cellular memory without regard to the specific cellular mechanisms encoding it. We then apply this framework to a strain of Bacillus subtilis engineered to report on commitment to sporulation and degradative enzyme (AprE) synthesisand estimate the capacity of these systems and growth dynamics to"remember" 10 distinct cell histories prior to application of a common stressor. The analysis suggests that B. subtilis remembers, both in short and long term, aspects of its cellhistory, and that this memory is distributed differently among the observables. While this study does not examine the mechanistic bases for memory, it presents a framework for quantifying memory in cellular behaviors and is thus a starting point for studying new questions about cellular regulation and evolutionary strategy.

  3. Thermal history dependence of superconducting properties in La2CuO4+δ

    International Nuclear Information System (INIS)

    Hirayama, T.; Nakagawa, M.; Sumiyama, A.; Oda, Y.

    1998-01-01

    We studied the thermal history dependence of the superconducting properties below/above room temperature (RT) in the ceramic La 2 CuO 4-δ with excess oxygen. The phase separation (O-rich phase: superconducting and O-poor phase: antiferromagnetic) was concluded to occur above 373 K, in contrast with the usual report of the phase separation around 320 K. As for the superconducting phases, the well-known T c onset of 32 or 36 K, dependent on thermal history around 200 K, in the samples annealed in high-pressure oxygen gas, was not changed by thermal history between RT and 373 K. The samples electrochemically oxidized at RT included the phase with the high T c of 45 K, which was not changed by thermal history below RT, and the phase with the low T c of 32 or 36 K. The 45 K phase was changed into the low-T c phase by annealing at 373 K. The samples electrochemically oxidized at 333 K, which was accompanied with the diffusion of excess oxygen, showed gradual change of superconducting behavior: the single low-T c (32 or 36 K) phase (oxidation time = 24 h), coexistence of the low-T c phase and the high-T c (45 K) phase (36 h), and the single high T c phase (48 and 72 h). Thus, the single superconducting phase with the high T c of 45 K has been obtained, which showed a metallic behavior in normal resistivity and apparent changes of lattice constant in comparison with that of stoichiometric La 2 CuO 4 . (orig.)

  4. Critical current characteristics and history dependence in superconducting SmFeAsOF bulk

    International Nuclear Information System (INIS)

    Ni, B; Ge, J; Kiuchi, M; Otabe, E S; Gao, Z; Wang, L; Qi, Y; Zhang, X; Ma, Y

    2010-01-01

    The superconducting SmFeAsO 1-x F x (x=0.2) polycrystalline bulks were prepared by the powder-in-tube (PIT) method. The magnetic field and temperature dependences of critical current densities in the samples were investigated by resistive and ac inductive (Campbell's) methods. It was found that a fairly large shielding current density over 10 9 A/m 2 , which is considered to correspond to the local critical current density, flows locally with the perimeter size similar to the average grain size of the bulk samples, while an extremely low transport current density of about 10 5 A/m 2 corresponding to the global critical current density flows through the whole sample. Furthermore, a unique history dependence of global critical current density was observed, i.e., it shows a smaller value in the increasing-field process than that in the decreasing-field process. The history dependence of global critical current characteristic in our case can be ascribed to the existence of the weak-link property between the grains in SmFeAsO 1-x F x bulk.

  5. History-dependent dynamics in a generic model of ion channels - an analytic study

    Directory of Open Access Journals (Sweden)

    Daniel Soudry

    2010-04-01

    Full Text Available Recent experiments have demonstrated that the timescale of adaptation of single neurons and ion channel populations to stimuli slows down as the length of stimulation increases; in fact, no upper bound on temporal time-scales seems to exist in such systems. Furthermore, patch clamp experiments on single ion channels have hinted at the existence of large, mostly unobservable, inactivation state spaces within a single ion channel. This raises the question of the relation between this multitude of inactivation states and the observed behavior. In this work we propose a minimal model for ion channel dynamics which does not assume any specific structure of the inactivation state space. The model is simple enough to render an analytical study possible. This leads to a clear and concise explanation of the experimentally observed exponential history-dependent relaxation in sodium channels in a voltage clamp setting, and shows that their recovery rate from slow inactivation must be voltage dependent. Furthermore, we predict that history-dependent relaxation cannot be created by overly sparse spiking activity. While the model was created with ion channel populations in mind, its simplicity and genericalness render it a good starting point for modeling similar effects in other systems, and for scaling up to higher levels such as single neurons which are also known to exhibit multiple time scales.

  6. Construction of Time-Dependent Spectra Using Wavelet Analysis for Determination of Global Damage

    DEFF Research Database (Denmark)

    Micaletti, R. C.; Cakmak, A. S.; Nielsen, Søren R.K.

    A new method for computing Maximum Softening Damage Index (MSDI) is proposed. The MSDI, a measure of global damage, is based on the relative reduction of the first eigenfrequency (or equivalently, the relative increase in the fundamental period) of a structure over the course of a damage event. T....... The method proposed here makes use of wavelet transform coefficients of measured output response records to provide time-localized information on structural softening....

  7. Twelve fundamental life histories evolving through allocation-dependent fecundity and survival.

    Science.gov (United States)

    Johansson, Jacob; Brännström, Åke; Metz, Johan A J; Dieckmann, Ulf

    2018-03-01

    An organism's life history is closely interlinked with its allocation of energy between growth and reproduction at different life stages. Theoretical models have established that diminishing returns from reproductive investment promote strategies with simultaneous investment into growth and reproduction (indeterminate growth) over strategies with distinct phases of growth and reproduction (determinate growth). We extend this traditional, binary classification by showing that allocation-dependent fecundity and mortality rates allow for a large diversity of optimal allocation schedules. By analyzing a model of organisms that allocate energy between growth and reproduction, we find twelve types of optimal allocation schedules, differing qualitatively in how reproductive allocation increases with body mass. These twelve optimal allocation schedules include types with different combinations of continuous and discontinuous increase in reproduction allocation, in which phases of continuous increase can be decelerating or accelerating. We furthermore investigate how this variation influences growth curves and the expected maximum life span and body size. Our study thus reveals new links between eco-physiological constraints and life-history evolution and underscores how allocation-dependent fitness components may underlie biological diversity.

  8. White Matter Changes in HIV+ Women with a History of Cocaine Dependence

    Directory of Open Access Journals (Sweden)

    Kathryn-Mary Wakim

    2017-10-01

    Full Text Available Cocaine use is associated with the transmission of human immunodeficiency (HIV virus through risky sexual behavior. In HIV+ individuals, cocaine use is linked with poor health outcomes, including HIV-medication non-adherence and faster disease progression. Both HIV and cocaine dependence are associated with reduced integrity of cerebral white matter (WM, but the effects of HIV during cocaine abstinence have not yet been explored. We used diffusion tensor imaging (DTI to understand the effect of combined HIV+ serostatus and former cocaine dependence on cerebral WM integrity. DTI data obtained from 15 HIV+ women with a history of cocaine dependence (COC+/HIV+ and 21 healthy females were included in the analysis. Diffusion-based measures [fractional anisotropy (FA, radial diffusivity (RD, mean diffusivity, and axial diffusivity] were examined using tract-based spatial statistics and region-of-interest analyses. In a whole-brain analysis, COC+/HIV+ women showed significantly reduced FA and increased RD in all major WM tracts, except the left corticospinal tract for RD. The tract with greatest percentage of voxels showing significant between-group differences was the forceps minor (FA: 75.6%, RD: 59.7%. These widespread changes in diffusion measures indicate an extensive neuropathological effect of HIV and former cocaine dependence on WM.

  9. Damage-Based Time-Dependent Modeling of Paraglacial to Postglacial Progressive Failure of Large Rock Slopes

    Science.gov (United States)

    Riva, Federico; Agliardi, Federico; Amitrano, David; Crosta, Giovanni B.

    2018-01-01

    Large alpine rock slopes undergo long-term evolution in paraglacial to postglacial environments. Rock mass weakening and increased permeability associated with the progressive failure of deglaciated slopes promote the development of potentially catastrophic rockslides. We captured the entire life cycle of alpine slopes in one damage-based, time-dependent 2-D model of brittle creep, including deglaciation, damage-dependent fluid occurrence, and rock mass property upscaling. We applied the model to the Spriana rock slope (Central Alps), affected by long-term instability after Last Glacial Maximum and representing an active threat. We simulated the evolution of the slope from glaciated conditions to present day and calibrated the model using site investigation data and available temporal constraints. The model tracks the entire progressive failure path of the slope from deglaciation to rockslide development, without a priori assumptions on shear zone geometry and hydraulic conditions. Complete rockslide differentiation occurs through the transition from dilatant damage to a compacting basal shear zone, accounting for observed hydraulic barrier effects and perched aquifer formation. Our model investigates the mechanical role of deglaciation and damage-controlled fluid distribution in the development of alpine rockslides. The absolute simulated timing of rock slope instability development supports a very long "paraglacial" period of subcritical rock mass damage. After initial damage localization during the Lateglacial, rockslide nucleation initiates soon after the onset of Holocene, whereas full mechanical and hydraulic rockslide differentiation occurs during Mid-Holocene, supporting a key role of long-term damage in the reported occurrence of widespread rockslide clusters of these ages.

  10. Level of hamstrings damage depending on force-generating capacity and creatine kinase activity

    OpenAIRE

    Carmona, Gerard; Alomar, Xavier; Mendiguchia, Jurdan; Serrano, David; Padullés, Josep Maria; Nescolarde Selva, Lexa Digna; Rodas Font, Gil; Cusso Calabuig, Roser; Guerrero, M.; Idoate, F.; Balius, Ramon; Cadefau, Joan

    2014-01-01

    The aim of the present study was to categorize the eccentric exercise-induced hamstrings damage by using easy measurable markers such as force-generating capacity and serum creatine kinase activity Peer Reviewed

  11. High-energy electron irradiation of NdFeB permanent magnets: Dependence of radiation damage on the electron energy

    International Nuclear Information System (INIS)

    Bizen, Teruhiko; Asano, Yoshihiro; Marechal, Xavier-Marie; Seike, Takamitsu; Aoki, Tsuyoshi; Fukami, Kenji; Hosoda, Naoyasu; Yonehara, Hiroto; Takagi, Tetsuya; Hara, Toru; Tanaka, Takashi; Kitamura, Hideo

    2007-01-01

    High-energy electron-beam bombardment of Nd 2 Fe 14 B-type permanent magnets induces radiation damage characterized by a drop in the magnetic field. Experiments carried out at the SPring-8 booster synchrotron, with 4, 6, and 8 GeV electrons, show that the drop in magnetic field is energy dependent. Electromagnetic shower simulations suggest that most of the radiation damage happens in a small region around the irradiation axis, and that the contribution of neutrons with large scattering angles or with low energies to the magnetic field change is small

  12. High-energy electron irradiation of NdFeB permanent magnets: Dependence of radiation damage on the electron energy

    Energy Technology Data Exchange (ETDEWEB)

    Bizen, Teruhiko [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan)]. E-mail: bizen@spring8.or.jp; Asano, Yoshihiro [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Marechal, Xavier-Marie [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Seike, Takamitsu [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Aoki, Tsuyoshi [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Fukami, Kenji [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Hosoda, Naoyasu [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Yonehara, Hiroto [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Takagi, Tetsuya [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Hara, Toru [RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Tanaka, Takashi [RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Kitamura, Hideo [RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

    2007-05-11

    High-energy electron-beam bombardment of Nd{sub 2}Fe{sub 14}B-type permanent magnets induces radiation damage characterized by a drop in the magnetic field. Experiments carried out at the SPring-8 booster synchrotron, with 4, 6, and 8 GeV electrons, show that the drop in magnetic field is energy dependent. Electromagnetic shower simulations suggest that most of the radiation damage happens in a small region around the irradiation axis, and that the contribution of neutrons with large scattering angles or with low energies to the magnetic field change is small.

  13. ATM-Dependent Phosphorylation of MEF2D Promotes Neuronal Survival after DNA Damage

    Science.gov (United States)

    Chan, Shing Fai; Sances, Sam; Brill, Laurence M.; Okamoto, Shu-ichi; Zaidi, Rameez; McKercher, Scott R.; Akhtar, Mohd W.; Nakanishi, Nobuki

    2014-01-01

    Mutations in the ataxia telangiectasia mutated (ATM) gene, which encodes a kinase critical for the normal DNA damage response, cause the neurodegenerative disorder ataxia-telangiectasia (AT). The substrates of ATM in the brain are poorly understood. Here we demonstrate that ATM phosphorylates and activates the transcription factor myocyte enhancer factor 2D (MEF2D), which plays a critical role in promoting survival of cerebellar granule cells. ATM associates with MEF2D after DNA damage and phosphorylates the transcription factor at four ATM consensus sites. Knockdown of endogenous MEF2D with a short-hairpin RNA (shRNA) increases sensitivity to etoposide-induced DNA damage and neuronal cell death. Interestingly, substitution of endogenous MEF2D with an shRNA-resistant phosphomimetic MEF2D mutant protects cerebellar granule cells from cell death after DNA damage, whereas an shRNA-resistant nonphosphorylatable MEF2D mutant does not. In vivo, cerebella in Mef2d knock-out mice manifest increased susceptibility to DNA damage. Together, our results show that MEF2D is a substrate for phosphorylation by ATM, thus promoting survival in response to DNA damage. Moreover, dysregulation of the ATM–MEF2D pathway may contribute to neurodegeneration in AT. PMID:24672010

  14. Dose-rate-dependent damage of cerium dioxide in the scanning transmission electron microscope.

    Science.gov (United States)

    Johnston-Peck, Aaron C; DuChene, Joseph S; Roberts, Alan D; Wei, Wei David; Herzing, Andrew A

    2016-11-01

    Beam damage caused by energetic electrons in the transmission electron microscope is a fundamental constraint limiting the collection of artifact-free information. Through understanding the influence of the electron beam, experimental routines may be adjusted to improve the data collection process. Investigations of CeO 2 indicate that there is not a critical dose required for the accumulation of electron beam damage. Instead, measurements using annular dark field scanning transmission electron microscopy and electron energy loss spectroscopy demonstrate that the onset of measurable damage occurs when a critical dose rate is exceeded. The mechanism behind this phenomenon is that oxygen vacancies created by exposure to a 300keV electron beam are actively annihilated as the sample re-oxidizes in the microscope environment. As a result, only when the rate of vacancy creation exceeds the recovery rate will beam damage begin to accumulate. This observation suggests that dose-intensive experiments can be accomplished without disrupting the native structure of the sample when executed using dose rates below the appropriate threshold. Furthermore, the presence of an encapsulating carbonaceous layer inhibits processes that cause beam damage, markedly increasing the dose rate threshold for the accumulation of damage. Published by Elsevier B.V.

  15. Childhood or adolescent parental divorce/separation, parental history of alcohol problems, and offspring lifetime alcohol dependence.

    Science.gov (United States)

    Thompson, Ronald G; Lizardi, Dana; Keyes, Katherine M; Hasin, Deborah S

    2008-12-01

    This study examined whether the experiences of childhood or adolescent parental divorce/separation and parental alcohol problems affected the likelihood of offspring DSM-IV lifetime alcohol dependence, controlling for parental history of drug, depression, and antisocial behavior problems. Data were drawn from the 2001-2002 National Epidemiological Survey on Alcohol and Related Conditions (NESARC), a nationally representative United States survey of 43,093 civilian non-institutionalized participants aged 18 and older, interviewed in person. Logistic regression models were used to calculate the main and interaction effects of childhood or adolescent parental divorce/separation and parental history of alcohol problems on offspring lifetime alcohol dependence, after adjusting for parental history of drug, depression, and antisocial behavior problems. Childhood or adolescent parental divorce/separation and parental history of alcohol problems were significantly related to offspring lifetime alcohol dependence, after adjusting for parental history of drug, depression, and antisocial behavior problems. Experiencing parental divorce/separation during childhood, even in the absence of parental history of alcohol problems, remained a significant predictor of lifetime alcohol dependence. Experiencing both childhood or adolescent parental divorce/separation and parental alcohol problems had a significantly stronger impact on the risk for DSM-IV alcohol dependence than the risk incurred by either parental risk factor alone. Further research is needed to better identify the factors that increase the risk for lifetime alcohol dependence among those who experience childhood or adolescent parental divorce/separation.

  16. Nonadjacent Dependency Learning in Cantonese-Speaking Children With and Without a History of Specific Language Impairment.

    Science.gov (United States)

    Iao, Lai-Sang; Ng, Lai Yan; Wong, Anita Mei Yin; Lee, Oi Ting

    2017-03-01

    This study investigated nonadjacent dependency learning in Cantonese-speaking children with and without a history of specific language impairment (SLI) in an artificial linguistic context. Sixteen Cantonese-speaking children with a history of SLI and 16 Cantonese-speaking children with typical language development (TLD) were tested with a nonadjacent dependency learning task using artificial languages that mimic Cantonese. Children with TLD performed above chance and were able to discriminate between trained and untrained nonadjacent dependencies. However, children with a history of SLI performed at chance and were not able to differentiate trained versus untrained nonadjacent dependencies. These findings, together with previous findings from English-speaking adults and adolescents with language impairments, suggest that individuals with atypical language development, regardless of age, diagnostic status, language, and culture, show difficulties in learning nonadjacent dependencies. This study provides evidence for early impairments to statistical learning in individuals with atypical language development.

  17. Sense of control under uncertainty depends on people's childhood environment: a life history theory approach.

    Science.gov (United States)

    Mittal, Chiraag; Griskevicius, Vladas

    2014-10-01

    Past research found that environmental uncertainty leads people to behave differently depending on their childhood environment. For example, economic uncertainty leads people from poor childhoods to become more impulsive while leading people from wealthy childhoods to become less impulsive. Drawing on life history theory, we examine the psychological mechanism driving such diverging responses to uncertainty. Five experiments show that uncertainty alters people's sense of control over the environment. Exposure to uncertainty led people from poorer childhoods to have a significantly lower sense of control than those from wealthier childhoods. In addition, perceptions of control statistically mediated the effect of uncertainty on impulsive behavior. These studies contribute by demonstrating that sense of control is a psychological driver of behaviors associated with fast and slow life history strategies. We discuss the implications of this for theory and future research, including that environmental uncertainty might lead people who grew up poor to quit challenging tasks sooner than people who grew up wealthy. 2014 APA, all rights reserved

  18. RUNX Family Participates in the Regulation of p53-Dependent DNA Damage Response

    Directory of Open Access Journals (Sweden)

    Toshinori Ozaki

    2013-01-01

    Full Text Available A proper DNA damage response (DDR, which monitors and maintains the genomic integrity, has been considered to be a critical barrier against genetic alterations to prevent tumor initiation and progression. The representative tumor suppressor p53 plays an important role in the regulation of DNA damage response. When cells receive DNA damage, p53 is quickly activated and induces cell cycle arrest and/or apoptotic cell death through transactivating its target genes implicated in the promotion of cell cycle arrest and/or apoptotic cell death such as p21WAF1, BAX, and PUMA. Accumulating evidence strongly suggests that DNA damage-mediated activation as well as induction of p53 is regulated by posttranslational modifications and also by protein-protein interaction. Loss of p53 activity confers growth advantage and ensures survival in cancer cells by inhibiting apoptotic response required for tumor suppression. RUNX family, which is composed of RUNX1, RUNX2, and RUNX3, is a sequence-specific transcription factor and is closely involved in a variety of cellular processes including development, differentiation, and/or tumorigenesis. In this review, we describe a background of p53 and a functional collaboration between p53 and RUNX family in response to DNA damage.

  19. Caffeine dependence in combination with a family history of alcoholism as a predictor of continued use of caffeine during pregnancy.

    Science.gov (United States)

    Svikis, Dace S; Berger, Nathan; Haug, Nancy A; Griffiths, Roland R

    2005-12-01

    The purpose of the study was to examine whether caffeine dependence and a family history of alcoholism are associated with continued use of caffeine during pregnancy. Forty-four women seeking obstetrical care in an office-based practice completed questionnaires and provided saliva samples at three prenatal visits occurring 2-3, 3-4, and 7 months postconception. On visit 1, the patients received the physician's instructions to stop using caffeine. Structured interviews were used to assign a diagnosis of caffeine dependence (lifetime) and to identify family history of alcoholism. Outcome measures included self-reported levels of caffeine use and saliva caffeine levels at the three prenatal visits. Although most women eliminated or substantially reduced their caffeine consumption between pregnancy awareness and prenatal visit 1, those with a lifetime diagnosis of caffeine dependence and a family history of alcoholism had higher levels of caffeine use and lower rates of abstinence throughout pregnancy. Saliva caffeine levels confirmed these effects. Withdrawal symptoms, functional impairment, and craving were cited as reasons they failed to eliminate or cut back on caffeine use. Fifty percent of the women with both a lifetime diagnosis of caffeine dependence and a family history of alcoholism continued to use caffeine in amounts (>300 mg/day) greater than those considered safe during pregnancy, compared to none of the women without caffeine dependence and a family history of alcoholism. Women with a lifetime diagnosis of caffeine dependence and a family history of alcoholism also reported higher rates of past cigarette smoking and problematic alcohol use. Caffeine-dependent women with a family history of alcoholism were not able to follow their physician's advice to reduce or eliminate caffeine consumption during pregnancy, despite their wanting to do so. This subgroup may require more intensive intervention to ensure caffeine abstinence and may be at greater risk for

  20. Lamin A/C-dependent interaction with 53BP1 promotes cellular responses to DNA damage

    DEFF Research Database (Denmark)

    Gibbs-Seymour, Ian; Markiewicz, Ewa; Bekker-Jensen, Simon

    2015-01-01

    Lamins A/C have been implicated in DNA damage response pathways. We show that the DNA repair protein 53BP1 is a lamin A/C binding protein. In undamaged human dermal fibroblasts (HDF), 53BP1 is a nucleoskeleton protein. 53BP1 binds to lamins A/C via its Tudor domain, and this is abrogated by DNA...... damage. Lamins A/C regulate 53BP1 levels and consequently lamin A/C-null HDF display a 53BP1 null-like phenotype. Our data favour a model in which lamins A/C maintain a nucleoplasmic pool of 53BP1 in order to facilitate its rapid recruitment to sites of DNA damage and could explain why an absence...

  1. Dose-rate and temperature dependent statistical damage accumulation model for ion implantation into silicon

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Mangas, J.M. [Dpto. de Electricidad y Electronica, Universidad de Valladolid, ETSI Telecomunicaciones, Campus Miguel Delibes, Valladolid E-47011 (Spain)]. E-mail: jesus.hernandez.mangas@tel.uva.es; Arias, J. [Dpto. de Electricidad y Electronica, Universidad de Valladolid, ETSI Telecomunicaciones, Campus Miguel Delibes, Valladolid E-47011 (Spain); Marques, L.A. [Dpto. de Electricidad y Electronica, Universidad de Valladolid, ETSI Telecomunicaciones, Campus Miguel Delibes, Valladolid E-47011 (Spain); Ruiz-Bueno, A. [Dpto. de Electricidad y Electronica, Universidad de Valladolid, ETSI Telecomunicaciones, Campus Miguel Delibes, Valladolid E-47011 (Spain); Bailon, L. [Dpto. de Electricidad y Electronica, Universidad de Valladolid, ETSI Telecomunicaciones, Campus Miguel Delibes, Valladolid E-47011 (Spain)

    2005-01-01

    Currently there are extensive atomistic studies that model some characteristics of the damage buildup due to ion irradiation (e.g. L. Pelaz et al., Appl. Phys. Lett. 82 (2003) 2038-2040). Our interest is to develop a novel statistical damage buildup model for our BCA ion implant simulator (IIS) code in order to extend its ranges of applicability. The model takes into account the abrupt regime of the crystal-amorphous transition. It works with different temperatures and dose-rates and also models the transition temperature. We have tested it with some projectiles (Ge, P) implanted into silicon. In this work we describe the new statistical damage accumulation model based on the modified Kinchin-Pease model. The results obtained have been compared with existing experimental results.

  2. Dose-rate and temperature dependent statistical damage accumulation model for ion implantation into silicon

    International Nuclear Information System (INIS)

    Hernandez-Mangas, J.M.; Arias, J.; Marques, L.A.; Ruiz-Bueno, A.; Bailon, L.

    2005-01-01

    Currently there are extensive atomistic studies that model some characteristics of the damage buildup due to ion irradiation (e.g. L. Pelaz et al., Appl. Phys. Lett. 82 (2003) 2038-2040). Our interest is to develop a novel statistical damage buildup model for our BCA ion implant simulator (IIS) code in order to extend its ranges of applicability. The model takes into account the abrupt regime of the crystal-amorphous transition. It works with different temperatures and dose-rates and also models the transition temperature. We have tested it with some projectiles (Ge, P) implanted into silicon. In this work we describe the new statistical damage accumulation model based on the modified Kinchin-Pease model. The results obtained have been compared with existing experimental results

  3. Squalene Inhibits ATM-Dependent Signaling in γIR-Induced DNA Damage Response through Induction of Wip1 Phosphatase.

    Directory of Open Access Journals (Sweden)

    Naoto Tatewaki

    Full Text Available Ataxia telangiectasia mutated (ATM kinase plays a crucial role as a master controller in the cellular DNA damage response. Inhibition of ATM leads to inhibition of the checkpoint signaling pathway. Hence, addition of checkpoint inhibitors to anticancer therapies may be an effective targeting strategy. A recent study reported that Wip1, a protein phosphatase, de-phosphorylates serine 1981 of ATM during the DNA damage response. Squalene has been proposed to complement anticancer therapies such as chemotherapy and radiotherapy; however, there is little mechanistic information supporting this idea. Here, we report the inhibitory effect of squalene on ATM-dependent DNA damage signals. Squalene itself did not affect cell viability and the cell cycle of A549 cells, but it enhanced the cytotoxicity of gamma-irradiation (γIR. The in vitro kinase activity of ATM was not altered by squalene. However, squalene increased Wip1 expression in cells and suppressed ATM activation in γIR-treated cells. Consistent with the potential inhibition of ATM by squalene, IR-induced phosphorylation of ATM effectors such as p53 (Ser15 and Chk1 (Ser317 was inhibited by cell treatment with squalene. Thus, squalene inhibits the ATM-dependent signaling pathway following DNA damage through intracellular induction of Wip1 expression.

  4. Temperature-dependent effect of filamentous cyanobacteria on Daphnia magna life history traits

    Directory of Open Access Journals (Sweden)

    Piotr DAWIDOWICZ

    2011-08-01

    Full Text Available Filamentous cyanobacteria are unsuitable food for Daphnia due to their poor manageability, poor nutritional value and, in some cases, toxicity. As the strength of harmful effects of cyanobacteria on filter-feeding zooplankton is temperature dependent, the global warming scenarios for eutrophic lakes in temperate zone might include an escalated suppression of Daphnia populations caused by the presence of cyanobacterial filaments. To test this assumption, we conducted life-table experiments with four clones of Daphnia magna fed either a green alga Scenedesmus obliquus or a non-toxic strain of filamentous cyanobacteria Cylindrospermopsis raciborskii in two temperatures (20 °C and 24 °C. Key life history parameters of Daphnia, i.e., age and size at first reproduction, fecundity, and individual growth rate, were measured. Both food and temperature significantly affected Daphnia performance, however, the effect of interaction of these two factors was ambiguous and highly genotype-dependent. We conclude that the temperature increase within the studied range will not necessarily strengthen the suppression of Daphnia growth by filamentous cyanobacteria, but may affect clonal selection within population of Daphnia, thus possibly triggering microevolutionary changes within affected populations.

  5. Magnetic history dependence of metastable states in thin films with dipolar interactions

    International Nuclear Information System (INIS)

    Iglesias, Oscar; Labarta, Amilcar

    2000-01-01

    We present the results of a Monte Carlo simulation of the ground state and magnetic relaxation of a model of a thin film consisting of a two-dimensional square lattice of Heisenberg spins with perpendicular anisotropy K, exchange J and long-range dipolar interactions g. We have studied the ground state configurations of this system for a wide range of the interaction parameters J/g, K/g by means of the simulated annealing procedure, showing that the model is able to reproduce the different magnetic configurations found in real samples. We have found the existence of a certain range of K/g, J/g values for which in-plane and out-of-plane configurations are quasi-degenerated in energy. We show that when a system in this region of parameters is perturbed by an external force that is subsequently removed, different kinds of ordering may be induced depending on the followed procedure. In particular, simulations of relaxations from saturation under an AC demagnetizing field or in zero field are in qualitative agreement with recent experiments on epitaxial and granular alloy thin films, which show a wide variety of magnetic patterns depending on their magnetic history

  6. Microglia kill amyloid-beta1-42 damaged neurons by a CD14-dependent process

    NARCIS (Netherlands)

    Bate, Clive; Veerhuis, Robert; Eikelenboom, Piet; Williams, Alun

    2004-01-01

    Activated microglia are closely associated with neuronal damage in Alzheimer's disease. In the present study, neurons exposed to low concentrations of amyloid-beta1-42, a toxic fragment of the amyloid-beta protein, were killed by microglia in a process that required cell-cell contact. Pre-treating

  7. Toxic effect of silica nanoparticles on endothelial cells through DNA damage response via Chk1-dependent G2/M checkpoint.

    Directory of Open Access Journals (Sweden)

    Junchao Duan

    Full Text Available Silica nanoparticles have become promising carriers for drug delivery or gene therapy. Endothelial cells could be directly exposed to silica nanoparticles by intravenous administration. However, the underlying toxic effect mechanisms of silica nanoparticles on endothelial cells are still poorly understood. In order to clarify the cytotoxicity of endothelial cells induced by silica nanoparticles and its mechanisms, cellular morphology, cell viability and lactate dehydrogenase (LDH release were observed in human umbilical vein endothelial cells (HUVECs as assessing cytotoxicity, resulted in a dose- and time- dependent manner. Silica nanoparticles-induced reactive oxygen species (ROS generation caused oxidative damage followed by the production of malondialdehyde (MDA as well as the inhibition of superoxide dismutase (SOD and glutathione peroxidase (GSH-Px. Both necrosis and apoptosis were increased significantly after 24 h exposure. The mitochondrial membrane potential (MMP decreased obviously in a dose-dependent manner. The degree of DNA damage including the percentage of tail DNA, tail length and Olive tail moment (OTM were markedly aggravated. Silica nanoparticles also induced G2/M arrest through the upregulation of Chk1 and the downregulation of Cdc25C, cyclin B1/Cdc2. In summary, our data indicated that the toxic effect mechanisms of silica nanoparticles on endothelial cells was through DNA damage response (DDR via Chk1-dependent G2/M checkpoint signaling pathway, suggesting that exposure to silica nanoparticles could be a potential hazards for the development of cardiovascular diseases.

  8. Protection against post-irradiation oxygen-dependent damage in barley seeds by catalase and hydrogen peroxide: probable radiation chemistry

    International Nuclear Information System (INIS)

    Singh, S.P.; Kesavan, P.C.

    1990-01-01

    Influence of varying concentration of catalase and H 2 O 2 administered individually and in combination treatment during post-hydration on the oxygen-dependent and -independent pathways of damage was assessed in dry barley seeds irradiated in vacuo with 350 Gy of 60 Co gammarays. Both catalase (100 to 500 units/ml) and H 2 O 2 (0.001 to 0.1 mM) afforded significant radioprotection against the post-irradiation O 2 -dependent damage. However, a combination treatment (300 units/ml of catalase and 0.01 mM of H 2 O 2 ) afforded significantl y more protection than either of the additives individually. None of the concentrations of catalase exerted any effect on the O 2 -independent pathway, whereas H 2 O 2 at higher concentrations (1 and 10 mM) significantly potentiated both the O 2 -dependent as well as the -independent components of radiation damage. These observations are better explicable in terms of radiation chemistry. (author). 16 refs., 3 tabs

  9. Caffeine potentiates or protects against radiation-induced DNA and chromosomal damage in human lymphocytes depending on temperature and concentration

    Energy Technology Data Exchange (ETDEWEB)

    Stoilov, L.M. (Department of Molecular Genetics, Institute of Genetics, Sofia (Bulgaria)); Mullenders, L.H.F.; Natarajan, A.T. (J.A. Cohen Institute, Interuniversity Research Institute for Radiopathology and Radiation Protection, Leiden (Netherlands))

    1994-12-01

    The effect of caffeine on radiation-induced chromosomal aberrations and DNA strand breaks in unstimulated human lymphocytes was investigated. When present prior to and during the radiation exposure, caffeine treatment was found to cause either potentiation or protection against induction of chromosomal aberrations depending on the concentration and temperature. When the nucleoid sedimentation technique was applied, enhancement or reduction of radiation-induced DNA strand breaks by caffeine was also found to be dependent on temperature and caffeine concentration. It is proposed that caffeine, in addition to its suspected ability to influence DNA repair, can also influence the induction of DNA damage, leading to alterations in the yield of chromosomal aberrations.

  10. Caffeine potentiates or protects against radiation-induced DNA and chromosomal damage in human lymphocytes depending on temperature and concentration

    International Nuclear Information System (INIS)

    Stoilov, L.M.; Mullenders, L.H.F.; Natarajan, A.T.

    1994-01-01

    The effect of caffeine on radiation-induced chromosomal aberrations and DNA strand breaks in unstimulated human lymphocytes was investigated. When present prior to and during the radiation exposure, caffeine treatment was found to cause either potentiation or protection against induction of chromosomal aberrations depending on the concentration and temperature. When the nucleoid sedimentation technique was applied, enhancement or reduction of radiation-induced DNA strand breaks by caffeine was also found to be dependent on temperature and caffeine concentration. It is proposed that caffeine, in addition to its suspected ability to influence DNA repair, can also influence the induction of DNA damage, leading to alterations in the yield of chromosomal aberrations

  11. Sample-length dependence of the critical current of slightly and significantly bent-damaged Bi2223 superconducting composite tape

    International Nuclear Information System (INIS)

    Ochiai, S; Fujimoto, M; Okuda, H; Oh, S S; Ha, D W

    2007-01-01

    The local critical current along a sample length is different from position to position in a long sample, especially when the sample is damaged by externally applied strain. In the present work, we attempted to reveal the relation of the distribution of the local critical current to overall critical current and the sample-length dependence of critical current for slightly and significantly damaged Bi2223 composite tape samples. In the experiment, 48 cm long Bi2223 composite tape samples, composed of 48 local elements with a length of 1 cm and 8 parts with a length 6 cm, were bent by 0.37 and 1.0% to cause slight and significant damage, respectively. The V-I curve, critical current (1 μV cm -1 criterion) and n value were measured for the overall sample as well as for the local elements and parts. It was found that the critical current distributions of the 1 cm elements at 0.37 and 1.0% bending strains are described by the three-parameter- and bimodal Weibull distribution functions, respectively. The critical current of a long sample at both bending strains could be described well by substituting the distributed critical current and n value of the short elements into the series circuit model for voltage generation. Also the measured relation of average critical current to sample length could be reproduced well in the computer by a Monte Carlo simulation method. It was shown that the critical current and n value decrease with increasing sample length at both bending strains. The extent of the decrease in critical current with sample length is dependent on the criterion of the critical current; the critical current decreases only slightly under the 1 μV cm -1 criterion which is not damage-sensitive, while it decreases greatly with increasing sample length under damage-sensitive criteria such as the 1 μV one

  12. Cell recovery in bronchoalveolar lavage fluid in smokers is dependent on cumulative smoking history.

    Directory of Open Access Journals (Sweden)

    Reza Karimi

    Full Text Available BACKGROUND: Smoking is a risk factor for various lung diseases in which BAL may be used as a part of a clinical investigation. Interpretation of BAL fluid cellularity is however difficult due to high variability, in particular among smokers. In this study we aimed to evaluate the effect of smoking on BAL cellular components in asymptomatic smokers. The effects of smoking cessation, age and gender were also investigated in groups of smokers and exsmokers. METHODS: We performed a retrospective review of BAL findings, to our knowledge the largest single center investigation, in our department from 1999 to 2009. One hundred thirty two current smokers (48 males and 84 females and 44 ex-smokers (16 males and 28 females were included. A group of 295 (132 males and 163 females never-smokers served as reference. RESULT: The median [5-95 pctl] total number of cells and cell concentration in current smokers were 63.4 [28.6-132.1]×10(6 and 382.1 [189.7-864.3]×10(6/L respectively and correlated positively to the cumulative smoking history. Macrophages were the predominant cell type (96.7% [90.4-99.0] followed by lymphocytes (2% [0.8-7.7] and neutrophils (0.6% [0-2.9]. The concentration of all inflammatory cells was increased in smokers compared to never smokers and ex-smokers. BAL fluid recovery was negatively correlated with age (p<0.001. Smoking men had a lower BAL fluid recovery than smoking women. CONCLUSION: Smoking has a profound effect on BAL fluid cellularity, which is dependent on smoking history. Our results performed on a large group of current smokers and ex-smokers in a well standardized way, can contribute to better interpretation of BAL fluid cellularity in clinical context.

  13. Generalization of motor learning depends on the history of prior action.

    Directory of Open Access Journals (Sweden)

    John W Krakauer

    2006-10-01

    Full Text Available Generalization of motor learning refers to our ability to apply what has been learned in one context to other contexts. When generalization is beneficial, it is termed transfer, and when it is detrimental, it is termed interference. Insight into the mechanism of generalization may be acquired from understanding why training transfers in some contexts but not others. However, identifying relevant contextual cues has proven surprisingly difficult, perhaps because the search has mainly been for cues that are explicit. We hypothesized instead that a relevant contextual cue is an implicit memory of action with a particular body part. To test this hypothesis we considered a task in which participants learned to control motion of a cursor under visuomotor rotation in two contexts: by moving their hand through motion of their shoulder and elbow, or through motion of their wrist. Use of these contextual cues led to three observations: First, in naive participants, learning in the wrist context was much faster than in the arm context. Second, generalization was asymmetric so that arm training benefited subsequent wrist training, but not vice versa. Third, in people who had prior wrist training, generalization from the arm to the wrist was blocked. That is, prior wrist training appeared to prevent both the interference and transfer that subsequent arm training should have caused. To explain the data, we posited that the learner collected statistics of contextual history: all upper arm movements also move the hand, but occasionally we move our hands without moving the upper arm. In a Bayesian framework, history of limb segment use strongly affects parameter uncertainty, which is a measure of the covariance of the contextual cues. This simple Bayesian prior dictated a generalization pattern that largely reproduced all three findings. For motor learning, generalization depends on context, which is determined by the statistics of how we have previously used

  14. Prediction of the time-dependent failure rate for normally operating components taking into account the operational history

    International Nuclear Information System (INIS)

    Vrbanic, I.; Simic, Z.; Sljivac, D.

    2008-01-01

    The prediction of the time-dependent failure rate has been studied, taking into account the operational history of a component used in applications such as system modeling in a probabilistic safety analysis in order to evaluate the impact of equipment aging and maintenance strategies on the risk measures considered. We have selected a time-dependent model for the failure rate which is based on the Weibull distribution and the principles of proportional age reduction by equipment overhauls. Estimation of the parameters that determine the failure rate is considered, including the definition of the operational history model and likelihood function for the Bayesian analysis of parameters for normally operating repairable components. The operational history is provided as a time axis with defined times of overhauls and failures. An example for demonstration is described with prediction of the future behavior for seven different operational histories. (orig.)

  15. Ultraviolet Laser Damage Dependence on Contamination Concentration in Fused Silica Optics during Reactive Ion Etching Process

    Directory of Open Access Journals (Sweden)

    Laixi Sun

    2018-04-01

    Full Text Available The reactive ion etching (RIE process of fused silica is often accompanied by surface contamination, which seriously degrades the ultraviolet laser damage performance of the optics. In this study, we find that the contamination behavior on the fused silica surface is very sensitive to the RIE process which can be significantly optimized by changing the plasma generating conditions such as discharge mode, etchant gas and electrode material. Additionally, an optimized RIE process is proposed to thoroughly remove polishing-introduced contamination and efficiently prevent the introduction of other contamination during the etching process. The research demonstrates the feasibility of improving the damage performance of fused silica optics by using the RIE technique.

  16. Surface-structure dependence of healing radiation-damage mechanism in nanoporous tungsten

    Science.gov (United States)

    Duan, Guohua; Li, Xiangyan; Sun, Jingjing; Hao, Congyu; Xu, Yichun; Zhang, Yange; Liu, Wei; Liu, C. S.

    2018-01-01

    Under nuclear fusion environments, displacement damage in tungsten (W) is usually caused by neutrons irradiation through producing large quantities of vacancies (Vs) and self-interstitial atoms (SIAs). These defects not only affect the mechanical properties of W, but also act as the trap sites for implanted hydrogen isotopes and helium. Nano-porous (NP) W with a high fraction of free surfaces has been developed to mitigate the radiation damage. However, the mechanism of the surface reducing defects accumulation is not well understood. By using multi-scale simulation methods, we investigated the interaction of the SIA and V with different surfaces on across length and time scales. We found that, at a typical operation temperature of 1000 K, surface (1 1 0) preferentially heals radiation damage of W compared with surface (1 0 0) and boundary (3 1 0). On surface (1 1 0), the diffusion barrier for the SIA is only 0.68 eV. The annihilation of the SIA-V happens via the coupled motion of the V segregation towards the surface from the bulk and the two-dimensional diffusion of the SIA on the surface. Such mechanism makes the surface (1 1 0) owe better healing capability. On surface (1 0 0), the diffusion energy barrier for the SIA is 2.48 eV, higher than the diffusion energy barrier of the V in bulk. The annihilation of the SIA-V occurs via the V segregation and recombination. The SIA was found to migrate one-dimensionally along a boundary (3 1 0) with a barrier of 0.21 eV, leading to a lower healing efficiency in the boundary. This study suggested that the on-surface process plays an important role in healing radiation damage of NP W in addition to surface-enhanced diffusion and annihilation near the surface. A certain surface structure renders nano-structured W more radiation-tolerant.

  17. ATM-dependent phosphorylation of Mdm2 on serine 395: role in p53 activation by DNA damage

    Science.gov (United States)

    Maya, Ruth; Balass, Moshe; Kim, Seong-Tae; Shkedy, Dganit; Leal, Juan-Fernando Martinez; Shifman, Ohad; Moas, Miri; Buschmann, Thomas; Ronai, Ze'ev; Shiloh, Yosef; Kastan, Michael B.; Katzir, Ephraim; Oren, Moshe

    2001-01-01

    The p53 tumor suppressor protein, a key regulator of cellular responses to genotoxic stress, is stabilized and activated after DNA damage. The rapid activation of p53 by ionizing radiation and radiomimetic agents is largely dependent on the ATM kinase. p53 is phosphorylated by ATM shortly after DNA damage, resulting in enhanced stability and activity of p53. The Mdm2 oncoprotein is a pivotal negative regulator of p53. In response to ionizing radiation and radiomimetic drugs, Mdm2 undergoes rapid ATM-dependent phosphorylation prior to p53 accumulation. This results in a decrease in its reactivity with the 2A10 monoclonal antibody. Phage display analysis identified a consensus 2A10 recognition sequence, possessing the core motif DYS. Unexpectedly, this motif appears twice within the human Mdm2 molecule, at positions corresponding to residues 258–260 and 393–395. Both putative 2A10 epitopes are highly conserved and encompass potential phosphorylation sites. Serine 395, residing within the carboxy-terminal 2A10 epitope, is the major target on Mdm2 for phosphorylation by ATM in vitro. Mutational analysis supports the conclusion that Mdm2 undergoes ATM-dependent phosphorylation on serine 395 in vivo in response to DNA damage. The data further suggests that phosphorylated Mdm2 may be less capable of promoting the nucleo-cytoplasmic shuttling of p53 and its subsequent degradation, thereby enabling p53 accumulation. Our findings imply that activation of p53 by DNA damage is achieved, in part, through attenuation of the p53-inhibitory potential of Mdm2. PMID:11331603

  18. Repair of Alkylation Damage in Eukaryotic Chromatin Depends on Searching Ability of Alkyladenine DNA Glycosylase.

    Science.gov (United States)

    Zhang, Yaru; O'Brien, Patrick J

    2015-11-20

    Human alkyladenine DNA glycosylase (AAG) initiates the base excision repair pathway by excising alkylated and deaminated purine lesions. In vitro biochemical experiments demonstrate that AAG uses facilitated diffusion to efficiently search DNA to find rare sites of damage and suggest that electrostatic interactions are critical to the searching process. However, it remains an open question whether DNA searching limits the rate of DNA repair in vivo. We constructed AAG mutants with altered searching ability and measured their ability to protect yeast from alkylation damage in order to address this question. Each of the conserved arginine and lysine residues that are near the DNA binding interface were mutated, and the functional impacts were evaluated using kinetic and thermodynamic analysis. These mutations do not perturb catalysis of N-glycosidic bond cleavage, but they decrease the ability to capture rare lesion sites. Nonspecific and specific DNA binding properties are closely correlated, suggesting that the electrostatic interactions observed in the specific recognition complex are similarly important for DNA searching complexes. The ability of the mutant proteins to complement repair-deficient yeast cells is positively correlated with the ability of the proteins to search DNA in vitro, suggesting that cellular resistance to DNA alkylation is governed by the ability to find and efficiently capture cytotoxic lesions. It appears that chromosomal access is not restricted and toxic sites of alkylation damage are readily accessible to a searching protein.

  19. PRAP1 is a novel executor of p53-dependent mechanisms in cell survival after DNA damage.

    Science.gov (United States)

    Huang, B H; Zhuo, J L; Leung, C H W; Lu, G D; Liu, J J; Yap, C T; Hooi, S C

    2012-12-13

    p53 has a crucial role in governing cellular mechanisms in response to a broad range of genotoxic stresses. During DNA damage, p53 can either promote cell survival by activating senescence or cell-cycle arrest and DNA repair to maintain genomic integrity for cell survival or direct cells to undergo apoptosis to eliminate extensively damaged cells. The ability of p53 to execute these two opposing cell fates depends on distinct signaling pathways downstream of p53. In this study, we showed that under DNA damage conditions induced by chemotherapeutic drugs, gamma irradiation and hydrogen peroxide, p53 upregulates a novel protein, proline-rich acidic protein 1 (PRAP1). We identified functional p53-response elements within intron 1 of PRAP1 gene and showed that these regions interact directly with p53 using ChIP assays, indicating that PRAP1 is a novel p53 target gene. The induction of PRAP1 expression by p53 may promote resistance of cancer cells to chemotherapeutic drugs such as 5-fluorouracil (5-FU), as knockdown of PRAP1 increases apoptosis in cancer cells after 5-FU treatment. PRAP1 appears to protect cells from apoptosis by inducing cell-cycle arrest, suggesting that the induction of PRAP1 expression by p53 in response to DNA-damaging agents contributes to cancer cell survival. Our findings provide a greater insight into the mechanisms underlying the pro-survival role of p53 in response to cytotoxic treatments.

  20. Frictional systems under periodic loads — History-dependence, non-uniqueness and energy dissipation

    International Nuclear Information System (INIS)

    Barber, J R

    2012-01-01

    Nominally static contacts such as bolted or shrink-fit joints typically experience regions of microslip when subjected to oscillatory loading. This results in energy dissipation, reflected as apparent hysteretic damping of the system, and also may cause the initiation of fretting fatigue cracks. Early theoretical studies of the Hertzian contact problem by Cattaneo and Mindlin were confirmed experimentally by Johnson, who identified signs of fretting damage in the slip annulus predicted by the theory. For many years, tribologists assumed that Melan's theorem in plasticity could be extended to frictional systems — i.e. that if there exists a state of residual stress associated with frictional slip that is sufficient to prevent periodic slip in the steady state, then the system will shake down, regardless of the initial condition. However, we now know that this is true only if there is no coupling between the normal and tangential loading problems, as will be the case notably when contact occurs on a symmetry plane. For all other cases, periodic loading scenarios can be devised such that shakedown occurs for some initial conditions and not for others. The initial condition here might be determined by the assembly protocol — e.g. the order in which a set of bolts is tightened — or by the exact loading path before the steady cycle is attained. This non-uniqueness of the steady state persists at load amplitudes above the shakedown limit, in which case there is always some dissipation, but the dissipation per cycle (and hence both the effective damping and the susceptibility to fretting damage) depends on the initial conditions. This implies that fretting fatigue experiments need to follow a well-defined assembly protocol if reproducible results are to be obtained. We shall also present results showing that when both normal and tangential forces vary in time, the energy dissipation is very sensitive to the relative phase of the oscillatory components, being greatest

  1. Thermal-history dependent magnetoelastic transition in (Mn,Fe){sub 2}(P,Si)

    Energy Technology Data Exchange (ETDEWEB)

    Miao, X. F., E-mail: x.f.miao@tudelft.nl; Dijk, N. H. van; Brück, E. [Fundamental Aspects of Materials and Energy, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Caron, L. [Fundamental Aspects of Materials and Energy, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, D-01187 Dresden (Germany); Gercsi, Z. [Blackett Laboratory, Department of Physics, Imperial College London, London SW7 2AZ (United Kingdom); CRANN and School of Physics, Trinity College Dublin, Dublin (Ireland); Daoud-Aladine, A. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom)

    2015-07-27

    The thermal-history dependence of the magnetoelastic transition in (Mn,Fe){sub 2}(P,Si) compounds has been investigated using high-resolution neutron diffraction. As-prepared samples display a large difference in paramagnetic-ferromagnetic (PM-FM) transition temperature compared to cycled samples. The initial metastable state transforms into a lower-energy stable state when the as-prepared sample crosses the PM-FM transition for the first time. This additional transformation is irreversible around the transition temperature and increases the energy barrier which needs to be overcome through the PM-FM transition. Consequently, the transition temperature on first cooling is found to be lower than on subsequent cycles characterizing the so-called “virgin effect.” High-temperature annealing can restore the cycled sample to the high-temperature metastable state, which leads to the recovery of the virgin effect. A model is proposed to interpret the formation and recovery of the virgin effect.

  2. History dependence and consequences of the microchemical evolution of AISI 316

    International Nuclear Information System (INIS)

    Garner, F.A.; Porter, D.L.

    1982-04-01

    The onset of void swelling in AISI 316 can be correlated with the removal of the elements nickel and silicon into precipitate phases. This conclusion was reached earlier based on measurement of microscopic volumes and has now been confirmed by the use of bulk extraction and elemental analysis of precipitates formed during irradiation. It appears that the average level of nickel remaining in the alloy matrix can be used as an index to assess the degree of completion of the microchemical evolution. The dependence of nickel removal on neutron flux and fluence, irradiation temperature, applied stress and preirradiation thermal-mechanical treatment is consistent with the behavior of swelling in response to these variables. It appears that at 400 0 C the microchemical evolution is very sluggish and still in progress at 14 x 10 22 n/cm 2 (E > 0.1 MeV). This suggests that the swelling rate at low temperatures will continue to increase with fluence and will approach that measured at higher temperatures. This higher swelling rate can be realized for some temperature histories which accelerate the kinetics of phase evolution

  3. Scaffolding across the lifespan in history-dependent decision-making.

    Science.gov (United States)

    Cooper, Jessica A; Worthy, Darrell A; Gorlick, Marissa A; Maddox, W Todd

    2013-06-01

    We examined the relationship between pressure and age-related changes in decision-making using a task for which currently available rewards depend on the participant's previous history of choices. Optimal responding in this task requires the participant to learn how his or her current choices affect changes in the future rewards given for each option. Building on the scaffolding theory of aging and cognition, we predicted that when additional frontal resources are available, compensatory recruitment leads to increased monitoring and increased use of heuristic-based strategies, ultimately leading to better performance. Specifically, we predicted that scaffolding would result in an age-related performance advantage under no pressure conditions. We also predicted that, although younger adults would engage in scaffolding under pressure, older adults would not have additional resources available for increased scaffolding under pressure-packed conditions, leading to an age-related performance deficit. Both predictions were supported by the data. In addition, computational models were used to evaluate decision-making strategies employed by each participant group. As expected, older adults under no pressure conditions and younger adults under pressure conditions showed increased use of heuristic-based strategies relative to older adults under pressure and younger adults under no pressure, respectively. These results are consistent with the notion that scaffolding can occur across the life span in the face of an environmental challenge. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  4. A chronic increase of corticosterone age-dependently reduces systemic DNA damage from oxidation in rats

    DEFF Research Database (Denmark)

    Jorgensen, Anders; Kalliokoski, Otto; Forsberg, Kristin

    2017-01-01

    Stress and depression are associated with an acceleration of brain and bodily aging; effects which have been attributed to chronic elevations of glucocorticoids. We tested the hypothesis that a three week administration of stress-associated levels of corticosterone (CORT, the principal rodent...... glucocorticoid) would increase systemic and CNS DNA and RNA damage from oxidation; a phenomenon known to be centrally involved in the aging process. We also hypothesized that older individuals would be more sensitive to this effect and that the chronic CORT administration would exacerbate age-related memory...

  5. A role for nuclear translocation of tripeptidyl-peptidase II in reactive oxygen species-dependent DNA damage responses

    Energy Technology Data Exchange (ETDEWEB)

    Preta, Giulio; Klark, Rainier de [Center for Molecular Medicine (CMM), Department of Medicine, Karolinska Institutet, Karolinska University Hospital, 171 76 Stockholm (Sweden); Glas, Rickard, E-mail: rickard.glas@ki.se [Center for Molecular Medicine (CMM), Department of Medicine, Karolinska Institutet, Karolinska University Hospital, 171 76 Stockholm (Sweden)

    2009-11-27

    Responses to DNA damage are influenced by cellular metabolism through the continuous production of reactive oxygen species (ROS), of which most are by-products of mitochondrial respiration. ROS have a strong influence on signaling pathways during responses to DNA damage, by relatively unclear mechanisms. Previous reports have shown conflicting data on a possible role for tripeptidyl-peptidase II (TPPII), a large cytosolic peptidase, within the DNA damage response. Here we show that TPPII translocated into the nucleus in a p160-ROCK-dependent fashion in response to {gamma}-irradiation, and that nuclear expression of TPPII was present in most {gamma}-irradiated transformed cell lines. We used a panel of nine cell lines of diverse tissue origin, including four lymphoma cell lines (T, B and Hodgkins lymphoma), a melanoma, a sarcoma, a colon and two breast carcinomas, where seven out of nine cell lines showed nuclear TPPII expression after {gamma}-irradiation. Further, this required cellular production of ROS; treatment with either N-acetyl-Cysteine (anti-oxidant) or Rotenone (inhibitor of mitochondrial respiration) inhibited nuclear accumulation of TPPII. The local density of cells was important for nuclear accumulation of TPPII at early time-points following {gamma}-irradiation (at 1-4 h), indicating a bystander effect. Further, we showed that the peptide-based inhibitor Z-Gly-Leu-Ala-OH, but not its analogue Z-Gly-(D)-Leu-Ala-OH, excluded TPPII from the nucleus. This correlated with reduced nuclear expression of p53 as well as caspase-3 and -9 activation in {gamma}-irradiated lymphoma cells. Our data suggest a role for TPPII in ROS-dependent DNA damage responses, through alteration of its localization from the cytosol into the nucleus.

  6. Time-dependent evolution of the excavation damaged zone in the argillaceous Tournemire site

    Energy Technology Data Exchange (ETDEWEB)

    Rejeb, A.; Cabrera, J. [Institut de Radioprotection et de Surete Nucleaire (IRSN/DEI/SARG), Lab. d' Etude Hydrodynamique et Geotechnique, 92 - Fontenay-aux-Roses (France)

    2006-07-01

    The experimental Tournemire site enables the assessment of the Excavation Damaged Zones (EDZ) around three structures excavated in argilites: the century-old tunnel, the ten year-old east and west galleries, and the three year-old main gallery. This paper discusses the main experimental results concerning the EDZ characterisation and their interpretation. EDZ fracture analyses from the galleries (cartography) and the radial boreholes (core analyses) allow for accurate structural characterisation of the EDZs. The tunnel has an EDZ with dense, homogeneous fracturing parallel to the wall, resembling onion skins. However, the new galleries do not have an EDZ similar to that of the tunnel. Unsaturated micro-cracks, mainly parallel to the bedding planes are observed on the non covered walls of each gallery. The extent of the EDZ does not seem to be affected by the age of the structure. It is approximately 20 % of the mean radius of the structure. Based on the modelling and experimental characterisation work completed, it is considered that the EDZ in this argillaceous Tournemire site is due to a deferred failure. At first time, when the wall of the structures are not covered the desaturation/re-saturation phenomena induced a tensile failure around the new galleries. During the time, these desaturation/re-saturation phenomena cause a gradual weakening of the material. The EDZ tunnel fractures are explained by this possible hydric damage and a decreasing mechanical strength with the time. These assumptions remain to be confirmed through coupled numerical modelling in unsaturated medium. (authors)

  7. Laser damage resistance of RbTiOPO(4): evidence of polarization dependent anisotropy.

    Science.gov (United States)

    Wagner, F R; Hildenbrand, A; Natoli, J Y; Commandré, M; Théodore, F; Albrecht, H

    2007-10-17

    Nanosecond-laser induced damage of RbTiOPO(4) crystals (RTP) has been studied at 1064 nm as a function of propagation direction and polarization orientation. A significant difference in the Laser Induced Damage Threshold (LIDT) was observed for x-cut and y-cut crystals in Pockels cell configuration, where the light propagation direction is along the x and y axes of the crystal respectively. In Pockels cell configuration the polarization is oriented at 45? with respect to the z-axis of the crystal. Experiments with the polarization oriented parallel to the principal axes of the crystal pointed out the importance of the polarization direction for the LIDT whereas the propagation direction did not significantly influence the LIDT. Comparison of the experimental data with a simple model reveals the influence of frequency doubling on the LIDT in Pockels cell configuration. In the case of the y-cut Pockels cell, the generation of frequency doubled light causes an LIDT below the LIDT of x and z-polarized light at the fundamental wavelength.

  8. Age-dependent oxidative stress-induced DNA damage in Down's lymphocytes

    International Nuclear Information System (INIS)

    Zana, Marianna; Szecsenyi, Anita; Czibula, Agnes; Bjelik, Annamaria; Juhasz, Anna; Rimanoczy, Agnes; Szabo, Krisztina; Vetro, Agnes; Szucs, Peter; Varkonyi, Agnes; Pakaski, Magdolna; Boda, Krisztina; Rasko, Istvan; Janka, Zoltan; Kalman, Janos

    2006-01-01

    The aim of the present study was to investigate the oxidative status of lymphocytes from children (n = 7) and adults (n = 18) with Down's syndrome (DS). The basal oxidative condition, the vulnerability to in vitro hydrogen peroxide exposure, and the repair capacity were measured by means of the damage-specific alkaline comet assay. Significantly and age-independently elevated numbers of single strand breaks and oxidized bases (pyrimidines and purines) were found in the nuclear DNA of the lymphocytes in the DS group in the basal condition. These results may support the role of an increased level of endogenous oxidative stress in DS and are similar to those previously demonstrated in Alzheimer's disease. In the in vitro oxidative stress-induced state, a markedly higher extent of DNA damage was observed in DS children as compared with age- and gender-matched healthy controls, suggesting that young trisomic lymphocytes are more sensitive to oxidative stress than normal ones. However, the repair ability itself was not found to be deteriorated in either DS children or DS adults

  9. Time-dependent evolution of the excavation damaged zone in the argillaceous Tournemire site

    International Nuclear Information System (INIS)

    Rejeb, A.; Cabrera, J.

    2006-01-01

    The experimental Tournemire site enables the assessment of the Excavation Damaged Zones (EDZ) around three structures excavated in argilites: the century-old tunnel, the ten year-old east and west galleries, and the three year-old main gallery. This paper discusses the main experimental results concerning the EDZ characterisation and their interpretation. EDZ fracture analyses from the galleries (cartography) and the radial boreholes (core analyses) allow for accurate structural characterisation of the EDZs. The tunnel has an EDZ with dense, homogeneous fracturing parallel to the wall, resembling onion skins. However, the new galleries do not have an EDZ similar to that of the tunnel. Unsaturated micro-cracks, mainly parallel to the bedding planes are observed on the non covered walls of each gallery. The extent of the EDZ does not seem to be affected by the age of the structure. It is approximately 20 % of the mean radius of the structure. Based on the modelling and experimental characterisation work completed, it is considered that the EDZ in this argillaceous Tournemire site is due to a deferred failure. At first time, when the wall of the structures are not covered the desaturation/re-saturation phenomena induced a tensile failure around the new galleries. During the time, these desaturation/re-saturation phenomena cause a gradual weakening of the material. The EDZ tunnel fractures are explained by this possible hydric damage and a decreasing mechanical strength with the time. These assumptions remain to be confirmed through coupled numerical modelling in unsaturated medium. (authors)

  10. Associations Between Family History of Substance Use, Childhood Trauma, and Age of First Drug Use in Persons With Methamphetamine Dependence.

    Science.gov (United States)

    Svingen, Leah; Dykstra, Rita E; Simpson, Jamie L; Jaffe, Anna E; Bevins, Rick A; Carlo, Gustavo; DiLillo, David; Grant, Kathleen M

    2016-01-01

    The current study examined the association among family history of substance use problems, childhood maltreatment, and age of first drug use in a sample of men and women seeking treatment for methamphetamine dependence. Various forms of childhood maltreatment were considered as mediators of the association between family history of substance use problems and age of first drug use. Participants (N = 99, 40% women, mean age 33) who were under treatment for methamphetamine dependence completed a baseline interview that obtained demographic information, past substance use by participants, history of drug/alcohol problems in their family of origin, and age at first use of any drug (excluding alcohol and tobacco). The Early Trauma Inventory Self-Report-Short Form was used to assess child maltreatment experiences before the age of 18. Family history of substance use problems and childhood physical (but not emotional or sexual) trauma significantly predicted age of first drug use. Further, childhood physical trauma mediated the association between family history of substance use problems and age of first drug use. These findings suggest that the experience of childhood physical abuse may be an important mechanism through which family history of substance use is associated with an earlier age of first drug use.

  11. Inhibition of autophagy enhances DNA damage-induced apoptosis by disrupting CHK1-dependent S phase arrest

    Energy Technology Data Exchange (ETDEWEB)

    Liou, Jong-Shian; Wu, Yi-Chen; Yen, Wen-Yen; Tang, Yu-Shuan [Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan, ROC (China); Kakadiya, Rajesh B.; Su, Tsann-Long [Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan, ROC (China); Yih, Ling-Huei, E-mail: lhyih@gate.sinica.edu.tw [Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan, ROC (China)

    2014-08-01

    DNA damage has been shown to induce autophagy, but the role of autophagy in the DNA damage response and cell fate is not fully understood. BO-1012, a bifunctional alkylating derivative of 3a-aza-cyclopenta[a]indene, is a potent DNA interstrand cross-linking agent with anticancer activity. In this study, BO-1012 was found to reduce DNA synthesis, inhibit S phase progression, and induce phosphorylation of histone H2AX on serine 139 (γH2AX) exclusively in S phase cells. Both CHK1 and CHK2 were phosphorylated in response to BO-1012 treatment, but only depletion of CHK1, but not CHK2, impaired BO-1012-induced S phase arrest and facilitated the entry of γH2AX-positive cells into G2 phase. CHK1 depletion also significantly enhanced BO-1012-induced cell death and apoptosis. These results indicate that BO-1012-induced S phase arrest is a CHK1-dependent pro-survival response. BO-1012 also resulted in marked induction of acidic vesicular organelle (AVO) formation and microtubule-associated protein 1 light chain 3 (LC3) processing and redistribution, features characteristic of autophagy. Depletion of ATG7 or co-treatment of cells with BO-1012 and either 3-methyladenine or bafilomycin A1, two inhibitors of autophagy, not only reduced CHK1 phosphorylation and disrupted S phase arrest, but also increased cleavage of caspase-9 and PARP, and cell death. These results suggest that cells initiate S phase arrest and autophagy as pro-survival responses to BO-1012-induced DNA damage, and that suppression of autophagy enhances BO-1012-induced apoptosis via disruption of CHK1-dependent S phase arrest. - Highlights: • Autophagy inhibitors enhanced the cytotoxicity of a DNA alkylating agent, BO-1012. • BO-1012-induced S phase arrest was a CHK1-dependent pro-survival response. • Autophagy inhibition enhanced BO-1012 cytotoxicity via disrupting the S phase arrest.

  12. The Mass-dependent Star Formation Histories of Disk Galaxies: Infall Model Versus Observations

    Science.gov (United States)

    Chang, R. X.; Hou, J. L.; Shen, S. Y.; Shu, C. G.

    2010-10-01

    We introduce a simple model to explore the star formation histories of disk galaxies. We assume that the disk originate and grows by continuous gas infall. The gas infall rate is parameterized by the Gaussian formula with one free parameter: the infall-peak time tp . The Kennicutt star formation law is adopted to describe how much cold gas turns into stars. The gas outflow process is also considered in our model. We find that, at a given galactic stellar mass M *, the model adopting a late infall-peak time tp results in blue colors, low-metallicity, high specific star formation rate (SFR), and high gas fraction, while the gas outflow rate mainly influences the gas-phase metallicity and star formation efficiency mainly influences the gas fraction. Motivated by the local observed scaling relations, we "construct" a mass-dependent model by assuming that the low-mass galaxy has a later infall-peak time tp and a larger gas outflow rate than massive systems. It is shown that this model can be in agreement with not only the local observations, but also with the observed correlations between specific SFR and galactic stellar mass SFR/M * ~ M * at intermediate redshifts z < 1. Comparison between the Gaussian-infall model and the exponential-infall model is also presented. It shows that the exponential-infall model predicts a higher SFR at early stage and a lower SFR later than that of Gaussian infall. Our results suggest that the Gaussian infall rate may be more reasonable in describing the gas cooling process than the exponential infall rate, especially for low-mass systems.

  13. Interrelationship between family history of alcoholism and generational status in the prediction of alcohol dependence in US Hispanics.

    Science.gov (United States)

    Chartier, K G; Thomas, N S; Kendler, K S

    2017-01-01

    Both a family history of alcoholism and migration-related factors like US v. foreign nativity increase the risk for developing alcohol use disorders in Hispanic Americans. For this study, we integrated these two lines of research to test whether the relationship between familial alcoholism and alcohol dependence changes with successive generations in the United States. Data were from the waves 1 and 2 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). Subjects self-identified Hispanic ethnicity (N = 4122; n = 1784 first, n = 1169 second, and n = 1169 third or later generation) and reported ever consuming ⩾12 drinks in a 1-year period. A family history of alcoholism was assessed in first- and second-degree relatives. Analyses predicting the number of alcohol dependence symptoms were path models. Alcohol dependence symptoms were associated with a stronger family history of alcoholism and later generational status. There was a significant interaction effect between familial alcoholism and generational status; the relationship of familial alcoholism with alcohol dependence symptoms increased significantly with successive generations in the United States, more strongly in women than men. Acculturation partially mediated the interaction effect between familial alcoholism and generational status on alcohol dependence, although not in the expected direction. Familial alcoholism interacted with generational status in predicting alcohol dependence symptoms in US Hispanic drinkers. This relationship suggests that heritability for alcoholism is influenced by a higher-order environmental factor, likely characterized by a relaxing of social restrictions on drinking.

  14. Implications of caspase-dependent proteolytic cleavage of cyclin A1 in DNA damage-induced cell death

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Sang Hyeok; Seo, Sung-Keum [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, 215-4 Gongneung-dong, Nowon-gu, Seoul (Korea, Republic of); An, Sungkwan; Choe, Tae-Boo [Department of Microbiological Engineering, Kon-Kuk University, Gwangjin-gu, Seoul (Korea, Republic of); Hong, Seok-Il [Department of Laboratory Medicine, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, 215-4 Gongneung-dong, Nowon-gu, Seoul (Korea, Republic of); Lee, Yun-Han, E-mail: yhlee87@yuhs.ac [Department of Radiation Oncology, College of Medicine, Yonsei University, 250 Seongsan-no, Seodaemun-gu, Seoul (Korea, Republic of); Park, In-Chul, E-mail: parkic@kcch.re.kr [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, 215-4 Gongneung-dong, Nowon-gu, Seoul (Korea, Republic of)

    2014-10-24

    Highlights: • Caspase-1 mediates doxorubicin-induced downregulation of cyclin A1. • Active caspase-1 effectively cleaved cyclin A1 at D165. • Cyclin A1 expression is involved in DNA damage-induced cell death. - Abstract: Cyclin A1 is an A-type cyclin that directly binds to CDK2 to regulate cell-cycle progression. In the present study, we found that doxorubicin decreased the expression of cyclin A1 at the protein level in A549 lung cancer cells, while markedly downregulating its mRNA levels. Interestingly, doxorubicin upregulated caspase-1 in a concentration-dependent manner, and z-YAVD-fmk, a specific inhibitor of caspase-1, reversed the doxorubicin-induced decrease in cyclin A1 in A549 lung cancer and MCF7 breast cancer cells. Active caspase-1 effectively cleaved cyclin A1 at D165 into two fragments, which in vitro cleavage assays showed were further cleaved by caspase-3. Finally, we found that overexpression of cyclin A1 significantly reduced the cytotoxicity of doxorubicin, and knockdown of cyclin A1 by RNA interference enhanced the sensitivity of cells to ionizing radiation. Our data suggest a new mechanism for the downregulation of cyclin A1 by DNA-damaging stimuli that could be intimately involved in the cell death induced by DNA damage-inducing stimuli, including doxorubicin and ionizing radiation.

  15. Critical involvement of the ATM-dependent DNA damage response in the apoptotic demise of HIV-1-elicited syncytia.

    Directory of Open Access Journals (Sweden)

    Jean-Luc Perfettini

    Full Text Available DNA damage can activate the oncosuppressor protein ataxia telangiectasia mutated (ATM, which phosphorylates the histone H2AX within characteristic DNA damage foci. Here, we show that ATM undergoes an activating phosphorylation in syncytia elicited by the envelope glycoprotein complex (Env of human immunodeficiency virus-1 (HIV-1 in vitro. This was accompanied by aggregation of ATM in discrete nuclear foci that also contained phospho-histone H2AX. DNA damage foci containing phosphorylated ATM and H2AX were detectable in syncytia present in the brain or lymph nodes from patients with HIV-1 infection, as well as in a fraction of blood leukocytes, correlating with viral status. Knockdown of ATM or of its obligate activating factor NBS1 (Nijmegen breakage syndrome 1 protein, as well as pharmacological inhibition of ATM with KU-55933, inhibited H2AX phosphorylation and prevented Env-elicited syncytia from undergoing apoptosis. ATM was found indispensable for the activation of MAP kinase p38, which catalyzes the activating phosphorylation of p53 on serine 46, thereby causing p53 dependent apoptosis. Both wild type HIV-1 and an HIV-1 mutant lacking integrase activity induced syncytial apoptosis, which could be suppressed by inhibiting ATM. HIV-1-infected T lymphoblasts from patients with inactivating ATM or NBS1 mutations also exhibited reduced syncytial apoptosis. Altogether these results indicate that apoptosis induced by a fusogenic HIV-1 Env follows a pro-apoptotic pathway involving the sequential activation of ATM, p38MAPK and p53.

  16. Progressive white matter microstructure damage in male chronic heroin dependent individuals: a DTI and TBSS study.

    Directory of Open Access Journals (Sweden)

    Yingwei Qiu

    Full Text Available BACKGROUND: To investigate the WM microstructure deficits in heroin dependent individuals (HDIs with different length of heroin dependence, and to investigate whether these WM deficits can be related to the duration of heroin use and to decision-making deficits in HDIs. METHODOLOGY/PRINCIPAL FINDINGS: Thirty-six HDIs [including eighteen sHDIs (duration of heroin dependent is less than 10 years and eighteen lHDIs (duration of dependent is between 10:20 years] and sixteen healthy controls participated in this study. Whole brain voxel-wise analysis of fractional anisotropy (FA, mean diffusivity (MD, axial diffusivity (Da and radial diffusivity (Dr were performed by tract-based spatial statistics (TBSS to localize abnormal WM regions among groups. TBSS demonstrated that sHDIs had significantly lower FA than controls in right orbito-frontal WM, bilateral temporal WM and right parietal WM. The lHDIs had significantly lower FA throughout the brain compared with the controls and sHDIs. The lHDIs had significantly lower Da than controls in bilateral inferior frontaloccipital fasciculus, bilateral splenium of corpus callosum, left inferior longitudinal fasciculus, and had significantly higher Dr than controls in bilateral uncinatus fasciculus, bilateral inferior frontaloccipital fasciculus and bilateral cortical spinal fasciculus. Volume-of-interest (VOI analyses detect the changes of diffusivity indices in the regions with FA abnormalities revealed by control vs sHDIs. In most VOIs, FA reductions were caused by the increase in Dr as well as the decrease in Da. Correlation analysis was used to assess the relationship between FA and behavioral measures in HDIs and controls available. Significantly positively correlations were found between the FA values in the right orbital-frontal WM, right parietal WM and IGT performance. CONCLUSIONS: The extent and severity of WM integrity deficits in HDIs was associated with the length of heroin dependent. Furthermore

  17. Optimal carbon emissions trajectories when damages depend on the rate or level of global warming

    International Nuclear Information System (INIS)

    Peck, S.C.; Teisberg, T.J.

    1994-01-01

    The authors extend earlier work with the Carbon Emissions Trajectory Assessment model (CETA) to consider a number of issues relating to the nature of optimal carbon emissions trajectories. They first explore model results when warming costs are associated with the rate of temperature rise, rather than with its level, as in earlier work. It is found that optimal trajectories are more strongly affected by the degree of non-linearity in the warming cost function than by whether the cost function is driven by the warming level or the warming rate. The authors briefly explore the implications of simple uncertainty and risk aversion for optimal emissions trajectories to be somewhat lower, but that the effect is not noticeable in the near term and not dramatic in the long term; the long term effect on the shadow price of carbon is more marked, however. Finally, they experiment with scaling up the warming cost functions until optimal policies are approximately the same as a policy of stabilising emissions at the 1990 level. Based on the results of this experiment, it is concluded that damages would have to be very high to justify anything like a stabilization policy; and even in this case, a policy allowing intertemporal variation in emissions would be better. 18 refs., 15 figs

  18. Dependence of Microelastic-plastic Nonlinearity of Martensitic Stainless Steel on Fatigue Damage Accumulation

    Science.gov (United States)

    Cantrell, John H.

    2006-01-01

    Self-organized substructural arrangements of dislocations formed in wavy slip metals during cyclic stress-induced fatigue produce substantial changes in the material microelastic-plastic nonlinearity, a quantitative measure of which is the nonlinearity parameter Beta extracted from acoustic harmonic generation measurements. The contributions to Beta from the substructural evolution of dislocations and crack growth for fatigued martensitic 410Cb stainless steel are calculated from the Cantrell model as a function of percent full fatigue life to fracture. A wave interaction factor f(sub WI) is introduced into the model to account experimentally for the relative volume of material fatigue damage included in the volume of material swept out by an interrogating acoustic wave. For cyclic stress-controlled loading at 551 MPa and f(sub WI) = 0.013 the model predicts a monotonic increase in Beta from dislocation substructures of almost 100 percent from the virgin state to roughly 95 percent full life. Negligible contributions from cracks are predicted in this range of fatigue life. However, over the last five percent of fatigue life the model predicts a rapid monotonic increase of Beta by several thousand percent that is dominated by crack growth. The theoretical predictions are in good agreement with experimental measurements of 410Cb stainless steel samples fatigued in uniaxial, stress-controlled cyclic loading at 551 MPa from zero to full tensile load with a measured f(sub WI) of 0.013.

  19. Inhibition of oxygen-dependent radiation-induced damage by the nitroxide superoxide dismutase mimic, tempol

    International Nuclear Information System (INIS)

    Mitchell, J.B.; DeGraff, W.; Kaufman, D.; Krishna, M.C.; Samuni, A.; Finkelstein, E.; Ahn, M.S.; Hahn, S.M.; Gamson, J.; Russo, A.

    1991-01-01

    Stable nitroxide radicals have been previously shown to function as superoxide dismutase (SOD)2 mimics and to protect mammalian cells against superoxide and hydrogen peroxide-mediated oxidative stress. These unique characteristics suggested that nitroxides, such as 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol), might protect mammalian cells against ionizing radiation. Treating Chinese hamster cells under aerobic conditions with 5, 10, 50, and 100 mM Tempol 10 min prior to X-rays resulted in radiation protection factors of 1.25, 1.30, 2.1, and 2.5, respectively. However, the reduced form of Tempol afforded no protection. Tempol treatment under hypoxic conditions did not provide radioprotection. Aerobic X-ray protection by Tempol could not be attributed to the induction of intracellular hypoxia, increase in intracellular glutathione, or induction of intracellular SOD mRNA. Tempol thus represents a new class of non-thiol-containing radiation protectors, which may be useful in elucidating the mechanism(s) of radiation-induced cellular damage and may have broad applications in protecting against oxidative stress

  20. Iron-Induced Damage in Cardiomyopathy: Oxidative-Dependent and Independent Mechanisms

    Directory of Open Access Journals (Sweden)

    Elena Gammella

    2015-01-01

    Full Text Available The high incidence of cardiomyopathy in patients with hemosiderosis, particularly in transfusional iron overload, strongly indicates that iron accumulation in the heart plays a major role in the process leading to heart failure. In this context, iron-mediated generation of noxious reactive oxygen species is believed to be the most important pathogenetic mechanism determining cardiomyocyte damage, the initiating event of a pathologic progression involving apoptosis, fibrosis, and ultimately cardiac dysfunction. However, recent findings suggest that additional mechanisms involving subcellular organelles and inflammatory mediators are important factors in the development of this disease. Moreover, excess iron can amplify the cardiotoxic effect of other agents or events. Finally, subcellular misdistribution of iron within cardiomyocytes may represent an additional pathway leading to cardiac injury. Recent advances in imaging techniques and chelators development remarkably improved cardiac iron overload detection and treatment, respectively. However, increased understanding of the pathogenic mechanisms of iron overload cardiomyopathy is needed to pave the way for the development of improved therapeutic strategies.

  1. Concentration-Dependent Protection by Ethanol Extract of Propolis against γ-Ray-Induced Chromosome Damage in Human Blood Lymphocytes

    Directory of Open Access Journals (Sweden)

    A. Montoro

    2011-01-01

    Full Text Available Radioprotection with natural products may be relevant to the mitigation of ionizing radiation-induced damage in mammalian systems; in this sense, propolis extracts have shown effects such as antioxidant, antitumoral, anti-inflammatory, and immunostimulant. We report for the first time a cytogenetic study to evaluate the radioprotective effect, in vitro, of propolis against radiation-induced chromosomal damage. Lymphocytes were cultured with increasing concentrations of ethanol extract of propolis (EEP, including 20, 40, 120, 250, 500, 750, 1000, and 2000 μg mL−1 and then exposed to 2 Gy γ-rays. A significant and concentration-dependent decrease is observed in the frequency of chromosome aberrations in samples treated with EEP. The protection against the formation of dicentrics was concentration-dependent, with a maximum protection at 120 μg mL−1 of EEP. The observed frequency of dicentrics is described as negative exponential function, indicating that the maximum protectible fraction of dicentrics is approximately 44%. Free radical scavenging and antioxidant activities are the mechanisms that these substances use to protect cells from ionizing radiation.

  2. Efficacy of serotonin in lessening radiation damage to mouse embryo depending on time of its administration following radiation exposure

    International Nuclear Information System (INIS)

    Konstantinova, M.M.; Dontsova, G.V.; Panaeva, S.V.; Turpaev, T.M.

    1994-01-01

    Our earlier studies demonstrated that serotonin lessons radiation damage to an 8-day mouse embryo. Moreover, this biogenic amine was equally effective when administered before and after intrauterine exposure of the embryo to ionizing radiation. The radiotherapeutic effect of serotonin was manifested by disorders in the embryo growth of various intensity, within the range of the studied radiation doses (1.31, 1.74, and 2.18 Gy). The therapeutic effect of serotonin in the embryos exposed to various doses of radiation depended on the amount of serotonin administered. The effective doses of this substance were determined by the severity of the damage inflicted. In this series of experiments, serotonin was administered immediately after exposure to ionizing radiation. The object of the present study was to determine whether or not the radiotherapeutic effect of serotonin depends on the time that elapses between the end of radiation exposure and the administration of serotonin to pregnant mice. It was established that serotonin produces a radiotherapeutic effect during 24 h following the intrauterine exposure of the fetus to ionizing radiation on the 8th day of gestation. The best therapeutic effect is attained with the administration of serotonin immediately after radiation exposure. The effect is slightly lower is serotonin is administered within 5 or 24 h following radiation exposure

  3. Roles of density-dependent growth and life history evolution in accounting for fisheries-induced trait changes.

    Science.gov (United States)

    Eikeset, Anne Maria; Dunlop, Erin S; Heino, Mikko; Storvik, Geir; Stenseth, Nils C; Dieckmann, Ulf

    2016-12-27

    The relative roles of density dependence and life history evolution in contributing to rapid fisheries-induced trait changes remain debated. In the 1930s, northeast Arctic cod (Gadus morhua), currently the world's largest cod stock, experienced a shift from a traditional spawning-ground fishery to an industrial trawl fishery with elevated exploitation in the stock's feeding grounds. Since then, age and length at maturation have declined dramatically, a trend paralleled in other exploited stocks worldwide. These trends can be explained by demographic truncation of the population's age structure, phenotypic plasticity in maturation arising through density-dependent growth, fisheries-induced evolution favoring faster-growing or earlier-maturing fish, or a combination of these processes. Here, we use a multitrait eco-evolutionary model to assess the capacity of these processes to reproduce 74 y of historical data on age and length at maturation in northeast Arctic cod, while mimicking the stock's historical harvesting regime. Our results show that model predictions critically depend on the assumed density dependence of growth: when this is weak, life history evolution might be necessary to prevent stock collapse, whereas when a stronger density dependence estimated from recent data is used, the role of evolution in explaining fisheries-induced trait changes is diminished. Our integrative analysis of density-dependent growth, multitrait evolution, and stock-specific time series data underscores the importance of jointly considering evolutionary and ecological processes, enabling a more comprehensive perspective on empirically observed stock dynamics than previous studies could provide.

  4. Strain-dependent Damage in Mouse Lung After Carbon Ion Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Moritake, Takashi [Advanced Radiation Biology Research Program, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Proton Medical Research Center, University of Tsukuba, Tsukuba (Japan); Fujita, Hidetoshi; Yanagisawa, Mitsuru; Nakawatari, Miyako; Imadome, Kaori; Nakamura, Etsuko; Iwakawa, Mayumi [Advanced Radiation Biology Research Program, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Imai, Takashi, E-mail: imait@nirs.go.jp [Advanced Radiation Biology Research Program, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan)

    2012-09-01

    Purpose: To examine whether inherent factors produce differences in lung morbidity in response to carbon ion (C-ion) irradiation, and to identify the molecules that have a key role in strain-dependent adverse effects in the lung. Methods and Materials: Three strains of female mice (C3H/He Slc, C57BL/6J Jms Slc, and A/J Jms Slc) were locally irradiated in the thorax with either C-ion beams (290 MeV/n, in 6 cm spread-out Bragg peak) or with {sup 137}Cs {gamma}-rays as a reference beam. We performed survival assays and histologic examination of the lung with hematoxylin-eosin and Masson's trichrome staining. In addition, we performed immunohistochemical staining for hyaluronic acid (HA), CD44, and Mac3 and assayed for gene expression. Results: The survival data in mice showed a between-strain variance after C-ion irradiation with 10 Gy. The median survival time of C3H/He was significantly shortened after C-ion irradiation at the higher dose of 12.5 Gy. Histologic examination revealed early-phase hemorrhagic pneumonitis in C3H/He and late-phase focal fibrotic lesions in C57BL/6J after C-ion irradiation with 10 Gy. Pleural effusion was apparent in C57BL/6J and A/J mice, 168 days after C-ion irradiation with 10 Gy. Microarray analysis of irradiated lung tissue in the three mouse strains identified differential expression changes in growth differentiation factor 15 (Gdf15), which regulates macrophage function, and hyaluronan synthase 1 (Has1), which plays a role in HA metabolism. Immunohistochemistry showed that the number of CD44-positive cells, a surrogate marker for HA accumulation, and Mac3-positive cells, a marker for macrophage infiltration in irradiated lung, varied significantly among the three mouse strains during the early phase. Conclusions: This study demonstrated a strain-dependent differential response in mice to C-ion thoracic irradiation. Our findings identified candidate molecules that could be implicated in the between-strain variance to early

  5. HTLV-1 Tax Oncoprotein Subverts the Cellular DNA Damage Response via Binding to DNA-dependent Protein Kinase*S⃞

    Science.gov (United States)

    Durkin, Sarah S.; Guo, Xin; Fryrear, Kimberly A.; Mihaylova, Valia T.; Gupta, Saurabh K.; Belgnaoui, S. Mehdi; Haoudi, Abdelali; Kupfer, Gary M.; Semmes, O. John

    2008-01-01

    Human T-cell leukemia virus type-1 is the causative agent for adult T-cell leukemia. Previous research has established that the viral oncoprotein Tax mediates the transformation process by impairing cell cycle control and cellular response to DNA damage. We showed previously that Tax sequesters huChk2 within chromatin and impairs the response to ionizing radiation. Here we demonstrate that DNA-dependent protein kinase (DNA-PK) is a member of the Tax·Chk2 nuclear complex. The catalytic subunit, DNA-PKcs, and the regulatory subunit, Ku70, were present. Tax-containing nuclear extracts showed increased DNA-PK activity, and specific inhibition of DNA-PK prevented Tax-induced activation of Chk2 kinase activity. Expression of Tax induced foci formation and phosphorylation of H2AX. However, Tax-induced constitutive signaling of the DNA-PK pathway impaired cellular response to new damage, as reflected in suppression of ionizing radiation-induced DNA-PK phosphorylation and γH2AX stabilization. Tax co-localized with phospho-DNA-PK into nuclear speckles and a nuclear excluded Tax mutant sequestered endogenous phospho-DNA-PK into the cytoplasm, suggesting that Tax interaction with DNA-PK is an initiating event. We also describe a novel interaction between DNA-PK and Chk2 that requires Tax. We propose that Tax binds to and stabilizes a protein complex with DNA-PK and Chk2, resulting in a saturation of DNA-PK-mediated damage repair response. PMID:18957425

  6. Recruitment kinetics of DNA repair proteins Mdc1 and Rad52 but not 53BP1 depend on damage complexity.

    Directory of Open Access Journals (Sweden)

    Volker Hable

    Full Text Available The recruitment kinetics of double-strand break (DSB signaling and repair proteins Mdc1, 53BP1 and Rad52 into radiation-induced foci was studied by live-cell fluorescence microscopy after ion microirradiation. To investigate the influence of damage density and complexity on recruitment kinetics, which cannot be done by UV laser irradiation used in former studies, we utilized 43 MeV carbon ions with high linear energy transfer per ion (LET = 370 keV/µm to create a large fraction of clustered DSBs, thus forming complex DNA damage, and 20 MeV protons with low LET (LET = 2.6 keV/µm to create mainly isolated DSBs. Kinetics for all three proteins was characterized by a time lag period T(0 after irradiation, during which no foci are formed. Subsequently, the proteins accumulate into foci with characteristic mean recruitment times τ(1. Mdc1 accumulates faster (T(0 = 17 ± 2 s, τ(1 = 98 ± 11 s than 53BP1 (T(0 = 77 ± 7 s, τ(1 = 310 ± 60 s after high LET irradiation. However, recruitment of Mdc1 slows down (T(0 = 73 ± 16 s, τ(1 = 1050 ± 270 s after low LET irradiation. The recruitment kinetics of Rad52 is slower than that of Mdc1, but exhibits the same dependence on LET. In contrast, the mean recruitment time τ(1 of 53BP1 remains almost constant when varying LET. Comparison to literature data on Mdc1 recruitment after UV laser irradiation shows that this rather resembles recruitment after high than low LET ionizing radiation. So this work shows that damage quality has a large influence on repair processes and has to be considered when comparing different studies.

  7. Topoisomerase II Inhibitors Induce DNA Damage-Dependent Interferon Responses Circumventing Ebola Virus Immune Evasion

    Directory of Open Access Journals (Sweden)

    Priya Luthra

    2017-04-01

    Full Text Available Ebola virus (EBOV protein VP35 inhibits production of interferon alpha/beta (IFN by blocking RIG-I-like receptor signaling pathways, thereby promoting virus replication and pathogenesis. A high-throughput screening assay, developed to identify compounds that either inhibit or bypass VP35 IFN-antagonist function, identified five DNA intercalators as reproducible hits from a library of bioactive compounds. Four, including doxorubicin and daunorubicin, are anthracycline antibiotics that inhibit topoisomerase II and are used clinically as chemotherapeutic drugs. These compounds were demonstrated to induce IFN responses in an ATM kinase-dependent manner and to also trigger the DNA-sensing cGAS-STING pathway of IFN induction. These compounds also suppress EBOV replication in vitro and induce IFN in the presence of IFN-antagonist proteins from multiple negative-sense RNA viruses. These findings provide new insights into signaling pathways activated by important chemotherapy drugs and identify a novel therapeutic approach for IFN induction that may be exploited to inhibit RNA virus replication.

  8. Context-dependent effects of hippocampal damage on memory in the shock-probe test.

    Science.gov (United States)

    Lehmann, Hugo; Carfagnini, Adrienne; Yamin, Stephanie; Mumby, Dave G

    2005-01-01

    We assessed the role of the hippocampus in anterograde memory, using the shock-probe test. Rats with sham or neurotoxic lesions of the hippocampus were given a shock-probe acquisition session during which each time they contacted a probe they received a shock; 24 h later, the rats were given a second shock-probe session to test their retention, but in this instance the probe was not electrified. Rats were tested in either the same context as the one used during acquisition or in a different context. The hippocampal lesions impaired avoidance of the probe and burying on the retention test, suggesting that the lesions induced anterograde amnesia. However, the impairment was context dependent. The hippocampal lesions impaired avoidance only when the rats were tested in the context in which they received the conditioning. The results of the shock-probe test suggest that the anterograde amnesia following hippocampal lesions is due mainly to an inability to associate the context with the shock more than to an inability to associate the probe with shock. Copyright (c) 2004 Wiley-Liss, Inc.

  9. LET dependence of the production of oxidative DNA damage in mammalian cells

    International Nuclear Information System (INIS)

    Ito, Atsushi; Furuichi, Wataru; Inoguchi, Hiroki; Hirayama, Ryoichi; Murayama, Chieko; Furusawa, Yoshiya

    2006-01-01

    Production of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in human leukemia HL-60 cells was examined upon irradiation with carbon, neon silicon ions. Cell suspension with the concentration of 1 x 10 7 /ml was irradiated tinder air-saturated condition. After irradiation cells were subjected to the DNA extraction using isopropanol, separation of DNA strands by heat treatment, digestion into nucleosides with nuclease P1 and alkaline phosphatase. A single peak of 8-OHdG on a chromatogram was observed using newly installed ECD detector (Coulochem III; ESA, Inc. U.S.A.). Reproducibility was also greatly improved with this detector. 8-OHdG yield was decreased with increasing linear energy transfer (LET) for carbon and silicon beam. These results are in good accordance with those of dG solution which was previously reported by us. Ion species dependence in 8-OHdG yield was not so apparent through the comparison of carbon and neon beam with an LET of 80 keV/μm and neon and silicon beam with an LET of 150 keV/μm. (author)

  10. UDP-glucuronosyltransferase-dependent bioactivation of clofibric acid to a DNA-damaging intermediate in mouse hepatocytes.

    Science.gov (United States)

    Ghaoui, Roula; Sallustio, Benedetta C; Burcham, Philip C; Fontaine, Frank R

    2003-05-06

    Glucuronidation of a number of carboxyl-containing drugs generates reactive acyl glucuronide metabolites. These electrophilic species alkylate cell proteins and may be implicated in the pathogenesis of a number of toxic syndromes seen in patients receiving the parent aglycones. Whether acyl glucuronides also attack nuclear DNA is unknown, although the acyl glucuronide formed from clofibric acid was recently found to decrease the transfection efficiency of phage DNA and generate strand breaks in plasmid DNA in vitro. To determine if such a DNA damage occurs within a cellular environment, the comet assay (i.e. single-cell gel electrophoresis) was used to detect DNA lesions in the nuclear genome of isolated mouse hepatocytes cultured with clofibric acid. Overnight exposure to 50 microM and higher concentrations of clofibric acid produced concentration-dependent increases in the comet areas of hepatocyte nuclei, with 1 mM clofibrate producing a 3.6-fold elevation over controls. These effects closely coincided with culture medium concentrations of the glucuronide metabolite formed from clofibric acid, 1-O-beta-clofibryl glucuronide. Consistent with a role for glucuronidation in the DNA damage observed, the glucuronidation inhibitor borneol diminished glucuronide formation from 100 microM clofibrate by 98% and returned comet areas to baseline levels. Collectively, these results suggest that the acyl glucuronide formed from clofibric acid is capable of migrating from its site of formation within the endoplasmic reticulum to generate strand nicks in nuclear DNA.

  11. Neutron diffraction study of history dependence in MnFeP0.6Si0.4

    International Nuclear Information System (INIS)

    Zhang, L.; Moze, O.; Prokes, K.; Tegus, O.; Brueck, E.

    2005-01-01

    In the MnFe(P,As) compounds which are promising magnetorefrigerant materials, we have studied the effect of Si substitution and successfully replaced As by Si. Surprisingly besides all the other changes, a peculiar history dependence of the magnetic phase transition was disclosed. The as-prepared sample shows a significantly lower transition temperature (namely a virgin T C ) than the sample that has experienced thermal cycling. The neutron diffraction patterns recorded during the first cooling manifest the first-order and magnetic-field-induced characters of the virgin phase transition. However, the refinement of the diffraction patterns does not provide evidence for atomic-position swapping, which might account for this history dependence

  12. Oncogenic RAS enables DNA damage- and p53-dependent differentiation of acute myeloid leukemia cells in response to chemotherapy.

    Directory of Open Access Journals (Sweden)

    Mona Meyer

    Full Text Available Acute myeloid leukemia (AML is a clonal disease originating from myeloid progenitor cells with a heterogeneous genetic background. High-dose cytarabine is used as the standard consolidation chemotherapy. Oncogenic RAS mutations are frequently observed in AML, and are associated with beneficial response to cytarabine. Why AML-patients with oncogenic RAS benefit most from high-dose cytarabine post-remission therapy is not well understood. Here we used bone marrow cells expressing a conditional MLL-ENL-ER oncogene to investigate the interaction of oncogenic RAS and chemotherapeutic agents. We show that oncogenic RAS synergizes with cytotoxic agents such as cytarabine in activation of DNA damage checkpoints, resulting in a p53-dependent genetic program that reduces clonogenicity and increases myeloid differentiation. Our data can explain the beneficial effects observed for AML patients with oncogenic RAS treated with higher dosages of cytarabine and suggest that induction of p53-dependent differentiation, e.g. by interfering with Mdm2-mediated degradation, may be a rational approach to increase cure rate in response to chemotherapy. The data also support the notion that the therapeutic success of cytotoxic drugs may depend on their ability to promote the differentiation of tumor-initiating cells.

  13. Metabolic response to MMS-mediated DNA damage in Saccharomyces cerevisiae is dependent on the glucose concentration in the medium.

    Science.gov (United States)

    Kitanovic, Ana; Walther, Thomas; Loret, Marie Odile; Holzwarth, Jinda; Kitanovic, Igor; Bonowski, Felix; Van Bui, Ngoc; Francois, Jean Marie; Wölfl, Stefan

    2009-06-01

    Maintenance and adaptation of energy metabolism could play an important role in the cellular ability to respond to DNA damage. A large number of studies suggest that the sensitivity of cells to oxidants and oxidative stress depends on the activity of cellular metabolism and is dependent on the glucose concentration. In fact, yeast cells that utilize fermentative carbon sources and hence rely mainly on glycolysis for energy appear to be more sensitive to oxidative stress. Here we show that treatment of the yeast Saccharomyces cerevisiae growing on a glucose-rich medium with the DNA alkylating agent methyl methanesulphonate (MMS) triggers a rapid inhibition of respiration and enhances reactive oxygen species (ROS) production, which is accompanied by a strong suppression of glycolysis. Further, diminished activity of pyruvate kinase and glyceraldehyde-3-phosphate dehydrogenase upon MMS treatment leads to a diversion of glucose carbon to glycerol, trehalose and glycogen accumulation and an increased flux through the pentose-phosphate pathway. Such conditions finally result in a significant decline in the ATP level and energy charge. These effects are dependent on the glucose concentration in the medium. Our results clearly demonstrate that calorie restriction reduces MMS toxicity through increased respiration and reduced ROS accumulation, enhancing the survival and recovery of cells.

  14. Characterizing and modeling the pressure- and rate-dependent elastic-plastic-damage behaviors of polypropylene-based polymers

    KAUST Repository

    Pulungan, Ditho Ardiansyah

    2018-02-24

    Polymers in general exhibit pressure- and rate-dependent behavior. Modeling such behavior requires extensive, costly and time-consuming experimental work. Common simplifications may lead to severe inaccuracy when using the model for predicting the failure of structures. Here, we propose a viscoelastic viscoplastic damage model for polypropylene-based polymers. Such a set of constitutive equations can be used to describe the response of polypropylene under various strain-rates and stress-triaxiality conditions. Our model can also be applied to a broad range of thermoplastic polymers. We detail the experimental campaign that is needed to identify every parameter of the model at best. We validated the proposed model by performing 3-point bending tests at different loading speeds, where the load-displacement response of polypropylene beam up to failure was accurately predicted.

  15. The AlkB Family of Fe(II)/α-Ketoglutarate-dependent Dioxygenases: Repairing Nucleic Acid Alkylation Damage and Beyond.

    Science.gov (United States)

    Fedeles, Bogdan I; Singh, Vipender; Delaney, James C; Li, Deyu; Essigmann, John M

    2015-08-21

    The AlkB family of Fe(II)- and α-ketoglutarate-dependent dioxygenases is a class of ubiquitous direct reversal DNA repair enzymes that remove alkyl adducts from nucleobases by oxidative dealkylation. The prototypical and homonymous family member is an Escherichia coli "adaptive response" protein that protects the bacterial genome against alkylation damage. AlkB has a wide variety of substrates, including monoalkyl and exocyclic bridged adducts. Nine mammalian AlkB homologs exist (ALKBH1-8, FTO), but only a subset functions as DNA/RNA repair enzymes. This minireview presents an overview of the AlkB proteins including recent data on homologs, structural features, substrate specificities, and experimental strategies for studying DNA repair by AlkB family proteins. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. State-dependent life-history strategies : A long-term study on oystercatchers

    NARCIS (Netherlands)

    van de Pol, Martijn

    2006-01-01

    The research described in this thesis is part of a long-term field study on free-living Oystercatchers (Haematopus ostralegus), on the Dutch Wadden Sea island of Schiermonnikoog.The study was started in 1983 by Jan Hulscher, and since then a lineage of PhDstudents has investigated life-history

  17. Increased dependence of action selection on recent motor history in Parkinson's disease.

    NARCIS (Netherlands)

    Helmich, R.C.G.; Aarts, E.; Lange, F.P. de; Bloem, B.R.; Toni, I.

    2009-01-01

    It is well known that the basal ganglia are involved in switching between movement sequences. Here we test the hypothesis that this contribution is an instance of a more general role of the basal ganglia in selecting actions that deviate from the context defined by the recent motor history, even

  18. Increased Dependence of Action Selection on Recent Motor History in Parkinson's Disease

    NARCIS (Netherlands)

    Helmich, R.C.G.; Aarts, E.; Lange, F.P. de; Bloem, B.R.; Toni, I.

    2009-01-01

    It is well known that the basal ganglia are involved in switching between movement sequences. Here we test the hypothesis that this contribution is an instance of a more general role of the basal ganglia in selecting actions that deviate from the context defined by the recent motor history, even

  19. Carbon sequestration potential of grazed pasture depends on prior management history

    Science.gov (United States)

    Grazed pastures are often assumed to be net sinks for removing carbon dioxide from the atmosphere and thus, are promoted as a management practice that can help mitigate climate change. The ability to serve as a C sink is especially pronounced following a history of tillage and row crop production. I...

  20. Dynamic Contractility and Efficiency Impairments in Stretch-Shortening Cycle Are Stretch-Load-Dependent After Training-Induced Muscle Damage

    NARCIS (Netherlands)

    Vaczi, Mark; Racz, Levente; Hortobagyi, Tibor; Tihanyi, Jozsef

    Vaczi, M, Racz, L, Hortobagyi, T, and Tihanyi, J. Dynamic contractility and efficiency impairments in stretch-shortening cycle are stretch-load-dependent after training-induced muscle damage. J Strength Cond Res 27(8): 2171-2179, 2013To determine the acute task and stretch-load dependency of

  1. Response of single bacterial cells to stress gives rise to complex history dependence at the population level

    Science.gov (United States)

    Mathis, Roland; Ackermann, Martin

    2016-01-01

    Most bacteria live in ever-changing environments where periods of stress are common. One fundamental question is whether individual bacterial cells have an increased tolerance to stress if they recently have been exposed to lower levels of the same stressor. To address this question, we worked with the bacterium Caulobacter crescentus and asked whether exposure to a moderate concentration of sodium chloride would affect survival during later exposure to a higher concentration. We found that the effects measured at the population level depended in a surprising and complex way on the time interval between the two exposure events: The effect of the first exposure on survival of the second exposure was positive for some time intervals but negative for others. We hypothesized that the complex pattern of history dependence at the population level was a consequence of the responses of individual cells to sodium chloride that we observed: (i) exposure to moderate concentrations of sodium chloride caused delays in cell division and led to cell-cycle synchronization, and (ii) whether a bacterium would survive subsequent exposure to higher concentrations was dependent on the cell-cycle state. Using computational modeling, we demonstrated that indeed the combination of these two effects could explain the complex patterns of history dependence observed at the population level. Our insight into how the behavior of single cells scales up to processes at the population level provides a perspective on how organisms operate in dynamic environments with fluctuating stress exposure. PMID:26960998

  2. On history dependence of stress-strain diagrams and creep curves under variable repeated loading

    International Nuclear Information System (INIS)

    Gokhfeld, D.A.; Sadakov, O.S.; Martynenko, M.E.

    1979-01-01

    The ability of structural alloys to 'keep in memory' the loading prehistory becomes of special importance when inelastic variable repeated loading is considered. There are two main approaches to the development of the mathematical description of this phenomenon: the inclusion of hidden state variables in the incremental theory constitutive equations (a) and construction of proper hereditary functionals (b). In this respect the assumption that the 'memory' regarding the previous deformation history is due to structural nonhomogeneity of actual materials proves to be fruitful. (orig.)

  3. Social cognition and aggression in methamphetamine dependence with and without a history of psychosis.

    Science.gov (United States)

    Uhlmann, Anne; Ipser, Jonathan C; Wilson, Don; Stein, Dan J

    2018-04-01

    In substance use and psychotic disorders, socially problematic behaviours, such as high aggression may, in part, be explained by deficits in social cognition skills, like the detection of emotions or intentions in others. The aim of this study was to assess the magnitude of social cognition impairment and its association with aggression in individuals with methamphetamine (MA) dependence, methamphetamine-associated psychosis (MAP), and healthy controls (CTRL). A total of 20 MAP participants, 21 MA-dependent participants without psychosis, and 21 CTRL participants performed a facial morphing emotion recognition task (ERT) across four basic emotions (anger, fear, happiness and sadness) and the reading the mind in the eyes task (RMET), and completed the aggression questionnaire. Both MA-dependent groups showed impairment in social cognition in terms of lower RMET scores relative to CTRL participants (MA; p = .047; MAP: p MAP (p = .040), compared to MA-dependent participants. While deficits in recognising emotional expressions were restricted to anger in the MA group (p = .020), a generalized impairment across all four emotions was observed in MAP (all p ≤ .001). Additionally, both patient groups demonstrated higher levels of aggression than CTRLs, yet no association was found with social cognition. This study supported the notion of deficits in recognising facial emotional expressions and inferring mental states of others in MA dependence, with additional impairments in MAP. Failure to detect an association between social cognitive impairment and aggressive behaviour may implicate independent disturbances of the two phenomena in MA dependence.

  4. History Dependence of the Microstructure on Time-Dependent Deformation During In-Situ Cooling of a Nickel-Based Single-Crystal Superalloy

    Science.gov (United States)

    Panwisawas, Chinnapat; D'Souza, Neil; Collins, David M.; Bhowmik, Ayan; Roebuck, Bryan

    2018-05-01

    Time-dependent plastic deformation through stress relaxation and creep deformation during in-situ cooling of the as-cast single-crystal superalloy CMSX-4® has been studied via neutron diffraction, transmission electron microscopy, electro-thermal miniature testing, and analytical modeling across two temperature regimes. Between 1000 °C and 900 °C, stress relaxation prevails and gives rise to softening as evidenced by a decreased dislocation density and the presence of long segment stacking faults in γ phase. Lattice strains decrease in both the γ matrix and γ' precipitate phases. A constitutive viscoplastic law derived from in-situ isothermal relaxation test under-estimates the equivalent plastic strain in the prediction of the stress and strain evolution during cooling in this case. It is thereby shown that the history dependence of the microstructure needs to be taken into account while deriving a constitutive law and which becomes even more relevant at high temperatures approaching the solvus. Higher temperature cooling experiments have also been carried out between 1300 °C and 1150 °C to measure the evolution of stress and plastic strain close to the γ' solvus temperature. In-situ cooling of samples using ETMT shows that creep dominates during high-temperature deformation between 1300 °C and 1220 °C, but below a threshold temperature, typically 1220 °C work hardening begins to prevail from increasing γ' fraction and resulting in a rapid increase in stress. The history dependence of prior accumulated deformation is also confirmed in the flow stress measurements using a single sample while cooling. The saturation stresses in the flow stress experiments show very good agreement with the stresses measured in the cooling experiments when viscoplastic deformation is dominant. This study demonstrates that experimentation during high-temperature deformation as well as the history dependence of the microstructure during cooling plays a key role in deriving

  5. Dependence of Hardness of Silicate Glasses on Composition and Thermal History

    DEFF Research Database (Denmark)

    Jensen, Martin; Smedskjær, Morten Mattrup; Yue, Yuanzheng

    composition on hardness of silicate glasses. E-glasses of different compositions are subjected to various degrees of annealing to obtain various fictive temperatures in the glasses. It is found that hardness decreases with the fictive temperature. Addition of Na2O to a SiO2-Al2O3-Na2O glass system causes......The prediction of hardness is possible for crystalline materials, but so far not possible for glasses. In this work, several important factors that should be used for predicting the hardness of glasses are discussed. To do so, we have studied the influences of thermal history and chemical...... a decrease in hardness. However, hardness cannot solely be determined from the degree of polymerisation of the glass network. It is also determined by the effect of ionic radius on hardness. However, this effect has opposite trend for alkali and alkaline earth ions. The hardness increases with ionic radius...

  6. Consider the category: The effect of spacing depends on individual learning histories.

    Science.gov (United States)

    Slone, Lauren K; Sandhofer, Catherine M

    2017-07-01

    The spacing effect refers to increased retention following learning instances that are spaced out in time compared with massed together in time. By one account, the advantages of spaced learning should be independent of task particulars and previous learning experiences given that spacing effects have been demonstrated in a variety of tasks across the lifespan. However, by another account, spaced learning should be affected by previous learning because past learning affects the memory and attention processes that form the crux of the spacing effect. The current study investigated whether individuals' learning histories affect the role of spacing in category learning. We examined the effect of spacing on 24 2- to 3.5-year-old children's learning of categories organized by properties to which children's previous learning experiences have biased them to attend (i.e., shape) and properties to which children are less biased to attend (i.e., texture and color). Spaced presentations led to significantly better learning of shape categories, but not of texture or color categories, compared with massed presentations. In addition, generalized estimating equations analyses revealed positive relations between the size of children's "shape-side" productive vocabularies and their shape category learning and between the size of children's "against-the-system" productive vocabularies and their texture category learning. These results suggest that children's attention to and memory for novel object categories are strongly related to their individual word-learning histories. Moreover, children's learned attentional biases affected the types of categories for which spacing facilitated learning. These findings highlight the importance of considering how learners' previous experiences may influence future learning. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Apatite fission track analysis: geological thermal history analysis based on a three-dimensional random process of linear radiation damage

    International Nuclear Information System (INIS)

    Galbraith, R.F.; Laslett, G.M.; Green, P.F.; Duddy, I.R.

    1990-01-01

    Spontaneous fission of uranium atoms over geological time creates a random process of linearly shaped features (fission tracks) inside an apatite crystal. The theoretical distributions associated with this process are governed by the elapsed time and temperature history, but other factors are also reflected in empirical measurements as consequences of sampling by plane section and chemical etching. These include geometrical biases leading to over-representation of long tracks, the shape and orientation of host features when sampling totally confined tracks, and 'gaps' in heavily annealed tracks. We study the estimation of geological parameters in the presence of these factors using measurements on both confined tracks and projected semi-tracks. Of particular interest is a history of sedimentation, uplift and erosion giving rise to a two-component mixture of tracks in which the parameters reflect the current temperature, the maximum temperature and the timing of uplift. A full likelihood analysis based on all measured densities, lengths and orientations is feasible, but because some geometrical biases and measurement limitations are only partly understood it seems preferable to use conditional likelihoods given numbers and orientations of confined tracks. (author)

  8. Economic value of ecological information in ecosystem-based natural resource management depends on exploitation history.

    Science.gov (United States)

    Essington, Timothy E; Sanchirico, James N; Baskett, Marissa L

    2018-02-13

    Ecosystem approaches to natural resource management are seen as a way to provide better outcomes for ecosystems and for people, yet the nature and strength of interactions among ecosystem components is usually unknown. Here we characterize the economic benefits of ecological knowledge through a simple model of fisheries that target a predator (piscivore) and its prey. We solve for the management (harvest) trajectory that maximizes net present value (NPV) for different ecological interactions and initial conditions that represent different levels of exploitation history. Optimal management trajectories generally approached similar harvest levels, but the pathways toward those levels varied considerably by ecological scenario. Application of the wrong harvest trajectory, which would happen if one type of ecological interaction were assumed but in fact another were occurring, generally led to only modest reductions in NPV. However, the risks were not equal across fleets: risks of incurring large losses of NPV and missing management targets were much higher in the fishery targeting piscivores, especially when piscivores were heavily depleted. Our findings suggest that the ecosystem approach might provide the greatest benefits when used to identify system states where management performs poorly with imperfect knowledge of system linkages so that management strategies can be adopted to avoid those states. Copyright © 2018 the Author(s). Published by PNAS.

  9. What shall I do now? State-dependent variations of life-history traits with aging in Wandering Albatrosses.

    Science.gov (United States)

    Pardo, Deborah; Barbraud, Christophe; Weimerskirch, Henri

    2014-02-01

    Allocation decisions depend on an organism's condition which can change with age. Two opposite changes in life-history traits are predicted in the presence of senescence: either an increase in breeding performance in late age associated with terminal investment or a decrease due to either life-history trade-offs between current breeding and future survival or decreased efficiency at old age. Age variation in several life-history traits has been detected in a number of species, and demographic performances of individuals in a given year are influenced by their reproductive state the previous year. Few studies have, however, examined state-dependent variation in life-history traits with aging, and they focused mainly on a dichotomy of successful versus failed breeding and non-breeding birds. Using a 50-year dataset on the long-lived quasi-biennial breeding wandering albatross, we investigated variations in life-history traits with aging according to a gradient of states corresponding to potential costs of reproduction the previous year (in ascending order): non-breeding birds staying at sea or present at breeding grounds, breeding birds that failed early, late or were successful. We used multistate models to study survival and decompose reproduction into four components (probabilities of return, breeding, hatching, and fledging), while accounting for imperfect detection. Our results suggest the possible existence of two strategies in the population: strict biennial breeders that exhibited almost no reproductive senescence and quasi-biennial breeders that showed an increased breeding frequency with a strong and moderate senescence on hatching and fledging probabilities, respectively. The patterns observed on survival were contrary to our predictions, suggesting an influence of individual quality rather than trade-offs between reproduction and survival at late ages. This work represents a step further into understanding the evolutionary ecology of senescence and its

  10. Repeatable aversion across threat types is linked with life-history traits but is dependent on how aversion is measured.

    Science.gov (United States)

    Davidson, Gabrielle L; Reichert, Michael S; Crane, Jodie M S; O'Shea, William; Quinn, John L

    2018-02-01

    Personality research suggests that individual differences in risk aversion may be explained by links with life-history variation. However, few empirical studies examine whether repeatable differences in risk avoidance behaviour covary with life-history traits among individuals in natural populations, or how these links vary depending on the context and the way risk aversion is measured. We measured two different risk avoidance behaviours (latency to enter the nest and inspection time) in wild great tits ( Parus major ) in two different contexts-response to a novel object and to a predator cue placed at the nest-box during incubation---and related these behaviours to female reproductive success and condition. Females responded equally strongly to both stimuli, and although both behaviours were repeatable, they did not correlate. Latency to enter was negatively related to body condition and the number of offspring fledged. By contrast, inspection time was directly explained by whether incubating females had been flushed from the nest before the trial began. Thus, our inferences on the relationship between risk aversion and fitness depend on how risk aversion was measured. Our results highlight the limitations of drawing conclusions about the relevance of single measures of a personality trait such as risk aversion.

  11. Ecological change points: The strength of density dependence and the loss of history.

    Science.gov (United States)

    Ponciano, José M; Taper, Mark L; Dennis, Brian

    2018-05-01

    Change points in the dynamics of animal abundances have extensively been recorded in historical time series records. Little attention has been paid to the theoretical dynamic consequences of such change-points. Here we propose a change-point model of stochastic population dynamics. This investigation embodies a shift of attention from the problem of detecting when a change will occur, to another non-trivial puzzle: using ecological theory to understand and predict the post-breakpoint behavior of the population dynamics. The proposed model and the explicit expressions derived here predict and quantify how density dependence modulates the influence of the pre-breakpoint parameters into the post-breakpoint dynamics. Time series transitioning from one stationary distribution to another contain information about where the process was before the change-point, where is it heading and how long it will take to transition, and here this information is explicitly stated. Importantly, our results provide a direct connection of the strength of density dependence with theoretical properties of dynamic systems, such as the concept of resilience. Finally, we illustrate how to harness such information through maximum likelihood estimation for state-space models, and test the model robustness to widely different forms of compensatory dynamics. The model can be used to estimate important quantities in the theory and practice of population recovery. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. CO2-level Dependent Effects of Ocean Acidification on Squid, Doryteuthis pealeii, Early Life History

    KAUST Repository

    Zakroff, Casey J.

    2013-12-01

    Ocean acidification is predicted to lead to global oceanic decreases in pH of up to 0.3 units within the next 100 years. However, those levels are already being reached currently in coastal regions due to natural CO2 variability. Squid are a vital component of the pelagic ecosystem, holding a unique niche as a highly active predatory invertebrate and major prey stock for upper trophic levels. This study examined the effects of a range of ocean acidification regimes on the early life history of a coastal squid species, the Atlantic longfin squid, Doryteuthis pealeii. Eggs were raised in a flow-through ocean acidification system at CO2 levels ranging from ambient (400ppm) to 2200ppm. Time to hatching, hatching efficiency, and hatchling mantle lengths, yolk sac sizes, and statoliths were all examined to elucidate stress effects. Delays in hatching time of at least a day were seen at exposures above 1300ppm in all trials under controlled conditions. Mantle lengths were significantly reduced at exposures above 1300 ppm. Yolk sac sizes varied between CO2 treatments, but no distinct pattern emerged. Statoliths were increasingly porous and malformed as CO2 exposures increased, and were significantly reduced in surface area at exposures above 1300ppm. Doryteuthis pealeii appears to be able to withstand acidosis stress without major effects up to 1300ppm, but is strongly impacted past that threshold. Since yolk consumption did not vary among treatments, it appears that during its early life stages, D. pealeii reallocates its available energy budget away from somatic growth and system development in order to mitigate the stress of acidosis.

  13. Predicting storage-dependent damage to red blood cells using nitrite oxidation kinetics, peroxiredoxin-2 oxidation, and hemoglobin and free heme measurements.

    Science.gov (United States)

    Oh, Joo-Yeun; Stapley, Ryan; Harper, Victoria; Marques, Marisa B; Patel, Rakesh P

    2015-12-01

    Storage-dependent damage to red blood cells (RBCs) varies significantly. Identifying RBC units that will undergo higher levels of hemolysis during storage may allow for more efficient inventory management decision-making. Oxidative-stress mediates storage-dependent damage to RBCs and will depend on the oxidant:antioxidant balance. We reasoned that this balance or redox tone will serve as a determinant of how a given RBC unit stores and that its assessment in "young" RBCs will predict storage-dependent hemolysis. RBCs were sampled from bags and segments stored for 7 to 42 days. Redox tone was assessed by nitrite oxidation kinetics and peroxiredoxin-2 (Prx-2) oxidation. In parallel, hemolysis was assessed by measuring cell-free hemoglobin (Hb) and free heme (hemin). Correlation analyses were performed to determine if Day 7 measurements predicted either the level of hemolysis at Day 35 or the increase in hemolysis during storage. Higher Day 7 Prx-2 oxidation was associated with higher Day 35 Prx-2 oxidation, suggesting that early assessment of this variable may identify RBCs that will incur the most oxidative damage during storage. RBCs that oxidized nitrite faster on Day 7 were associated with the greatest levels of storage-dependent hemolysis and increases in Prx-2 oxidation. An inverse relationship between storage-dependent changes in oxyhemoglobin and free heme was observed underscoring an unappreciated reciprocity between these molecular species. Moreover, free heme was higher in the bag compared to paired segments, with opposite trends observed for free Hb. Measurement of Prx-2 oxidation and nitrite oxidation kinetics early during RBC storage may predict storage-dependent damage to RBC including hemolysis-dependent formation of free Hb and heme. © 2015 AABB.

  14. Smoking history, nicotine dependence and opioid use in patients with chronic non-malignant pain

    DEFF Research Database (Denmark)

    Plesner, K; Jensen, H I; Højsted, J

    2016-01-01

    doses than never smokers and former smokers not using nicotine. CONCLUSIONS: The study supports previous evidence that smoking is associated with chronic pain. Our data suggest that information about use of nicotine substitution in chronic non-malignant patients are relevant both in a clinical setting......BACKGROUND: Previous studies have demonstrated a positive association between smoking and addiction to opioids in patients with chronic non-malignant pain. This could be explained by a susceptibility in some patients to develop addiction. Another explanation could be that nicotine influences both...... pain and the opioid system. The objective of the study was to investigate whether smoking, former smoking ± nicotine use and nicotine dependence in patients with chronic non-malignant pain were associated with opioid use and addiction to opioids. METHODS: The study was a cross-sectional study carried...

  15. Identification of corrosion and damage mechanisms by using scanning electron microscopy and energy-dispersive X-ray microanalysis: contribution to failure analysis case histories

    Science.gov (United States)

    Pantazopoulos, G.; Vazdirvanidis, A.

    2014-03-01

    Emphasis is placed on the evaluation of corrosion failures of copper and machineable brass alloys during service. Typical corrosion failures of the presented case histories mainly focussed on stress corrosion cracking and dezincification that acted as the major degradation mechanisms in components used in piping and water supply systems. SEM assessment, coupled with EDS spectroscopy, revealed the main cracking modes together with the root-source(s) that are responsible for the damage initiation and evolution. In addition, fracture surface observations contributed to the identification of the incurred fracture mechanisms and potential environmental issues that stimulated crack initiation and propagation. Very frequently, the detection of chlorides among the corrosion products served as a suggestive evidence of the influence of working environment on passive layer destabilisation and metal dissolution.

  16. Herbivores sculpt leaf traits differently in grasslands depending on life form and land-use histories.

    Science.gov (United States)

    Firn, Jennifer; Schütz, Martin; Nguyen, Huong; Risch, Anita C

    2017-01-01

    Vertebrate and invertebrate herbivores alter plant communities directly by selectively consuming plant species; and indirectly by inducing morphological and physiological changes to plant traits that provide competitive or survivorship advantages to some life forms over others. Progressively excluding aboveground herbivore communities (ungulates, medium and small sized mammals, invertebrates) over five growing seasons, we explored how leaf morphology (specific leaf area or SLA) and nutrition (nitrogen, carbon, phosphorous, potassium, sodium, and calcium) of different plant life forms (forbs, legumes, grasses, sedges) correlated with their dominance. We experimented in two subalpine grassland types with different land-use histories: (1) heavily grazed, nutrient-rich, short-grass vegetation and (2) lightly grazed, lower nutrient tall-grass vegetation. We found differences in leaf traits between treatments where either all herbivores were excluded or all herbivores were present, showing the importance of considering the impacts of both vertebrates and invertebrates on the leaf traits of plant species. Life forms responses to the progressive exclusion of herbivores were captured by six possible combinations: (1) increased leaf size and resource use efficiency (leaf area/nutrients) where lower nutrient levels are invested in leaf construction, but a reduction in the number of leaves, for example, forbs in both vegetation types, (2) increased leaf size and resource use efficiency, for example, legumes in short grass, (3) increased leaf size but a reduction in the number of leaves, for example, legumes in the tall grass, (4) increased number of leaves produced and increased resource use efficiency, for example, grasses in the short grass, (5) increased resource use efficiency of leaves only, for example, grasses and sedges in the tall grass, and (6) no response in terms of leaf construction or dominance, for example, sedges in the short grass. Although we found multiple

  17. Programming of left hand exploits task set but that of right hand depends on recent history.

    Science.gov (United States)

    Tang, Rixin; Zhu, Hong

    2017-07-01

    There are many differences between the left hand and the right hand. But it is not clear if there is a difference in programming between left hand and right hand when the hands perform the same movement. In current study, we carried out two experiments to investigate whether the programming of two hands was equivalent or they exploited different strategies. In the first experiment, participants were required to use one hand to grasp an object with visual feedback or to point to the center of one object without visual feedback on alternate trials, or to grasp an object without visual feedback and to point the center of one object with visual feedback on alternating trials. They then performed the tasks with the other hand. The result was that previous pointing task affected current grasping when it was performed by the left hand, but not the right hand. In experiment 2, we studied if the programming of the left (or right) hand would be affected by the pointing task performed on the previous trial not only by the same hand, but also by the right (or left) hand. Participants pointed and grasped the objects alternately with two hands. The result was similar with Experiment 1, i.e., left-hand grasping was affected by right-hand pointing, whereas right-hand grasping was immune from the interference from left hand. Taken together, the results suggest that when open- and closed-loop trials are interleaved, motor programming of grasping with the right hand was affected by the nature of the online feedback on the previous trial only if it was a grasping trial, suggesting that the trial-to-trial transfer depends on sensorimotor memory and not on task set. In contrast, motor programming of grasping with the left hand can use information about the nature of the online feedback on the previous trial to specify the parameters of the movement, even when the type of movement that occurred was quite different (i.e., pointing) and was performed with the right hand. This suggests that

  18. Non-adjacent dependency learning in Cantonese-speaking\\ud children with and without a history of specific language\\ud impairment

    OpenAIRE

    Iao, L-S; Ng, LY; Wong, AMY; Lee, OT

    2017-01-01

    Purpose: This study investigated non-adjacent dependency learning in Cantonese-speaking children with and without a history of Specific Language Impairment (SLI) in an artificial linguistic context.\\ud \\ud Method: Sixteen Cantonese-speaking children with SLI history and 16 Cantonese-speaking children with typical language development (TLD) were tested with a non-adjacent dependency learning task using artificial languages that mimic Cantonese.\\ud \\ud Results: Children with TLD performed above...

  19. Reactivity effect of spent fuel depending on burn-up history

    International Nuclear Information System (INIS)

    Hayashi, Takafumi; Suyama, Kenya; Nomura, Yasushi

    2001-06-01

    It is well known that a composition of spent fuel depends on various parameter changes throughout a burn-up period. In this study we aimed at the boron concentration and its change, the coolant temperature and its spatial distribution, the specific power, the operation mode, and the duration of inspection, because the effects due to these parameters have not been analyzed in detail. The composition changes of spent fuel were calculated by using the burn-up code SWAT, when the parameters mentioned above varied in the range of actual variations. Moreover, to estimate the reactivity effect caused by the composition changes, the criticality calculations for an infinite array of spent fuel were carried out with computer codes SRAC95 or MVP. In this report the reactivity effects were arranged from the viewpoint of what parameters gave more positive reactivity effect. The results obtained through this study are useful to choose the burn-up calculation model when we take account of the burn-up credit in the spent fuel management. (author)

  20. Effect of Shear History on Rheology of Time-Dependent Colloidal Silica Gels

    Directory of Open Access Journals (Sweden)

    Paulo H. S. Santos

    2017-11-01

    Full Text Available This paper presents a rheological study describing the effects of shear on the flow curves of colloidal gels prepared with different concentrations of fumed silica (4%, 5%, 6%, and 7% and a hydrophobic solvent (Hydrocarbon fuel, JP-8. Viscosity measurements as a function of time were carried out at different shear rates (10, 50, 100, 500, and 1000 s−1, and based on this data, a new structural kinetics model was used to describe the system. Previous work has based the analysis of time dependent fluids on the viscosity of the intact material, i.e., before it is sheared, which is a condition very difficult to achieve when weak gels are tested. The simple action of loading the gel in the rheometer affects its structure and rheology, and the reproducibility of the measurements is thus seriously compromised. Changes in viscosity and viscoelastic properties of the sheared material are indicative of microstructural changes in the gel that need to be accounted for. Therefore, a more realistic method is presented in this work. In addition, microscopical images (Cryo-SEM were obtained to show how the structure of the gel is affected upon application of shear.

  1. Slx4 becomes phosphorylated after DNA damage in a Mec1/Tel1-dependent manner and is required for repair of DNA alkylation damage

    Science.gov (United States)

    Flott, Sonja; Rouse, John

    2005-01-01

    Members of the RecQ family of DNA helicases, mutated in several syndromes associated with cancer predisposition, are key regulators of genome stability. The Saccharomyces cerevisiae SLX4 gene is required for cell viability in the absence of Sgs1, the only yeast RecQ helicase. SLX4 encodes one subunit of the heterodimeric Slx1–Slx4 endonuclease, although its cellular function is not clear. Slx1–Slx4 was reported to preferentially cleave replication fork-like structures in vitro, and cells lacking SLX4 are hypersensitive to DNA alkylation damage. Here we report that Slx4 becomes phosphorylated in cells exposed to a wide range of genotoxins. Even though it has been proposed that the role of Slx4 is restricted to S-phase, Slx4 phosphorylation is observed in cells arrested in G1 or G2 phases of the cell cycle, but not during an unperturbed cell cycle. Slx4 phosphorylation is completely abolished in cells lacking the Mec1 and Tel1 protein kinases, critical regulators of genome stability, but is barely affected in the absence of both Rad53 and Chk1 kinases. Finally we show that, whereas both Slx1 and Slx4 are dispensable for activation of cell-cycle checkpoints, Slx4, but not Slx1, is required for repair of DNA alkylation damage in both aynchronously growing cells and in G2-phase-arrested cells. These results reveal Slx4 as a new target of the Mec1/Tel1 kinases, with a crucial role in DNA repair that is not restricted to the processing of stalled replisomes. PMID:15975089

  2. Yields of clustered DNA damage induced by charged-particle radiations of similar kinetic energy per nucleon: LET dependence in different DNA microenvironments

    International Nuclear Information System (INIS)

    Keszenman, D.J.; Sutherland, B.M.

    2010-01-01

    To determine the linear energy transfer (LET) dependence of the biological effects of densely ionizing radiation in relation to changes in the ionization density along the track, we measured the yields and spectrum of clustered DNA damages induced by charged particles of different atomic number but similar kinetic energy per nucleon in different DNA microenvironments. Yeast DNA embedded in agarose in solutions of different free radical scavenging capacity was irradiated with 1 GeV protons, 1 GeV/nucleon oxygen ions, 980 MeV/nucleon titanium ions or 968 MeV/nucleon iron ions. The frequencies of double-strand breaks (DSBs), abasic sites and oxypurine clusters were quantified. The total DNA damage yields per absorbed dose induced in non-radioquenching solution decreased with LET, with minor variations in radioquenching conditions being detected. However, the total damage yields per particle fluence increased with LET in both conditions, indicating a higher efficiency per particle to induce clustered DNA damages. The yields of DSBs and non-DSB clusters as well as the damage spectra varied with LET and DNA milieu, suggesting the involvement of more than one mechanism in the formation of the different types of clustered damages.

  3. Effects of working memory load, a history of conduct disorder, and sex on decision making in substance dependent individuals.

    Science.gov (United States)

    Fridberg, Daniel J; Gerst, Kyle R; Finn, Peter R

    2013-12-01

    Substance dependence and antisocial psychopathology, such as a history of childhood conduct disorder (HCCD), are associated with impulsive or disadvantageous decision making and reduced working memory capacity (WMC). Reducing WMC via a working memory load increases disadvantageous decision making in healthy adults, but no previous studies have examined this effect in young adults with substance dependence and HCCD. Young adults with substance dependence (SubDep; n=158, 71 female), substance dependence and HCCD (SubDep+HCCD; n=72, 24 female), and control participants (n=152, 84 female) completed a test of decision making (the Iowa Gambling Task; IGT) with or without a concurrent working memory load intended to tax WMC. Outcomes were (i) net advantageous decisions on the IGT, and (ii) preferences for infrequent- versus frequent-punishment decks. SubDep+HCCD men made fewer advantageous decisions on the IGT than control men without a load, but there were no group differences among women in that condition. Load was associated with fewer advantageous decisions for SubDep+HCCD women and control men, but not for men or women in the other groups. Participants showed greater preference for infrequent-punishment, advantageous decks under load as well. There are gender differences in the effects of substance dependence, HCCD, and working memory load on decision making on the IGT. Decision making by control men and SubDep+HCCD women suffered the most under load. Load increases preferences for less-frequent punishments, similar to a delay discounting effect. Future research should clarify the cognitive and neural mechanisms underlying these effects. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  4. ATM-dependent E2F1 accumulation in the nucleolus is an indicator of ribosomal stress in early response to DNA damage.

    Science.gov (United States)

    Jin, Ya-Qiong; An, Guo-Shun; Ni, Ju-Hua; Li, Shu-Yan; Jia, Hong-Ti

    2014-01-01

    The nucleolus plays a major role in ribosome biogenesis. Most genotoxic agents disrupt nucleolar structure and function, which results in the stabilization/activation of p53, inducing cell cycle arrest or apoptosis. Likewise, transcription factor E2F1 as a DNA damage responsive protein also plays roles in cell cycle arrest, DNA repair, or apoptosis in response to DNA damage through transcriptional response and protein-protein interaction. Furthermore, E2F1 is known to be involved in regulating rRNA transcription. However, how E2F1 displays in coordinating DNA damage and nucleolar stress is unclear. In this study, we demonstrate that ATM-dependent E2F1 accumulation in the nucleolus is a characteristic feature of nucleolar stress in early response to DNA damage. We found that at the early stage of DNA damage, E2F1 accumulation in the nucleolus was an ATM-dependent and a common event in p53-suficient and -deficient cells. Increased nucleolar E2F1 was sequestered by the nucleolar protein p14ARF, which repressed E2F1-dependent rRNA transcription initiation, and was coupled with S phase. Our data indicate that early accumulation of E2F1 in the nucleolus is an indicator for nucleolar stress and a component of ATM pathway, which presumably buffers elevation of E2F1 in the nucleoplasm and coordinates the diversifying mechanisms of E2F1 acts in cell cycle progression and apoptosis in early response to DNA damage.

  5. Structural damage to lymphocyte nuclei by H2O2 or gamma irradiation is dependent on the mechanism of OH anion radical production

    International Nuclear Information System (INIS)

    Allan, I.M.; Vaughan, A.T.M.; Milner, A.E.; Lunec, J.; Bacon, P.A.

    1988-01-01

    Normal human lymphocytes were exposed to OH anion radicals produced indirectly by exposure to H 2 O 2 or directly by gamma irradiation. Using a flow cytometry technique to measure changes in nucleoid size, it was found that generation of OH anion in each system produced a characteristic relaxation in nuclear supercoiling. Exposure of cells to H 2 O 2 produced a metal-dependent step-wise relaxation in extracted nucleoids, while gamma irradiation induced a gradual dose-dependent increase in nucleoid size. The site-specific metal-dependent changes produced in lymphocytes incubated in H 2 O 2 should also occur in gamma irradiated cells, but the characteristic effects on nuclear supercoiling would not be detected within the background of random DNA damage. The importance of metals in maintaining the supercoiled loop configuration of DNA within the protein matrix suggests that free radical damage at metal locations may be particularly toxic for the cell. (author)

  6. DEPENDENCE OF DISTRIBUTION FUNCTION OF COMMERCIAL DAMAGES DUE TO POSSIBLE EARTHQUAKES ON THE CLASS OF SEISMIC RESISTANCE OF A BUILDING

    Directory of Open Access Journals (Sweden)

    Hanzada R. Zajnulabidova

    2017-01-01

    Full Text Available Abstract. Objectives To determine the damage probability of earthquakes of different intensities on the example of a real projected railway station building having a framework design scheme based on the density function of damage distribution. Methods Uncertainty, always existing in nature, invalidates a deterministic approach to the assessment of territorial seismic hazards and, consequently, seismic risk. In this case, seismic risk assessment can be carried out on a probabilistic basis. Thus, the risk will always be there, but it must be minimised. The task of optimising the reinforcement costs is solved by using the density distribution function for seismic effects of varying intensity, taking into account the degree of building responsibility. Results The distribution functions of the expected damage for a building with a reinforced concrete frame located in a highly seismic region with a repetition of 9-point shocks every 500 years and 10-point shocks once every 5000 years are constructed. A significant effect of the seismic resistance class of a building on the form of the distribution functions is shown. For structures of a high seismic resistance class, not only is the seismic risk reduced, but also the variance of the expected damage. From the graphs obtained, it can be seen that the seismic resistance class significantly affects the damage distribution. At a probability of 0.997, the expected damage for a non-reinforced building will exceed 43%; for a reinforced one it is only 10%. It also follows from the graphs that the variance of the damage magnitude decreases with the growth of the seismic resistance class of the building. This fact is an additional incentive for investing in antiseismic reinforcement of buildings. Conclusion The study shows the expediency of working with the damage density distribution function when managing seismic risk. In this case, it becomes possible to strengthen the building with a specified probability of

  7. DEPENDENCE OF DISTRIBUTION FUNCTION OF COMMERCIAL DAMAGES DUE TO POSSIBLE EARTHQUAKES ON THE CLASS OF SEISMIC RESISTANCE OF A BUILDING

    OpenAIRE

    Hanzada R. Zajnulabidova; Alexander M. Uzdin; Tatiana M. Chirkst

    2017-01-01

    Abstract. Objectives To determine the damage probability of earthquakes of different intensities on the example of a real projected railway station building having a framework design scheme based on the density function of damage distribution. Methods Uncertainty, always existing in nature, invalidates a deterministic approach to the assessment of territorial seismic hazards and, consequently, seismic risk. In this case, seismic risk assessment can be carried out on a probabilistic basis. Thu...

  8. The telomeric protein TRF2 binds the ATM kinase and can inhibit the ATM-dependent DNA damage response.

    Directory of Open Access Journals (Sweden)

    Jan Karlseder

    2004-08-01

    Full Text Available The telomeric protein TRF2 is required to prevent mammalian telomeres from activating DNA damage checkpoints. Here we show that overexpression of TRF2 affects the response of the ATM kinase to DNA damage. Overexpression of TRF2 abrogated the cell cycle arrest after ionizing radiation and diminished several other readouts of the DNA damage response, including phosphorylation of Nbs1, induction of p53, and upregulation of p53 targets. TRF2 inhibited autophosphorylation of ATM on S1981, an early step in the activation of this kinase. A region of ATM containing S1981 was found to directly interact with TRF2 in vitro, and ATM immunoprecipitates contained TRF2. We propose that TRF2 has the ability to inhibit ATM activation at telomeres. Because TRF2 is abundant at chromosome ends but not elsewhere in the nucleus, this mechanism of checkpoint control could specifically block a DNA damage response at telomeres without affecting the surveillance of chromosome internal damage.

  9. Application of a time-dependent coalescence process for inferring the history of population size changes from DNA sequence data.

    Science.gov (United States)

    Polanski, A; Kimmel, M; Chakraborty, R

    1998-05-12

    Distribution of pairwise differences of nucleotides from data on a sample of DNA sequences from a given segment of the genome has been used in the past to draw inferences about the past history of population size changes. However, all earlier methods assume a given model of population size changes (such as sudden expansion), parameters of which (e.g., time and amplitude of expansion) are fitted to the observed distributions of nucleotide differences among pairwise comparisons of all DNA sequences in the sample. Our theory indicates that for any time-dependent population size, N(tau) (in which time tau is counted backward from present), a time-dependent coalescence process yields the distribution, p(tau), of the time of coalescence between two DNA sequences randomly drawn from the population. Prediction of p(tau) and N(tau) requires the use of a reverse Laplace transform known to be unstable. Nevertheless, simulated data obtained from three models of monotone population change (stepwise, exponential, and logistic) indicate that the pattern of a past population size change leaves its signature on the pattern of DNA polymorphism. Application of the theory to the published mtDNA sequences indicates that the current mtDNA sequence variation is not inconsistent with a logistic growth of the human population.

  10. XRCC1 coordinates disparate responses and multiprotein repair complexes depending on the nature and context of the DNA damage

    DEFF Research Database (Denmark)

    Hanssen-Bauer, Audun; Solvang-Garten, Karin; Sundheim, Ottar

    2011-01-01

    . We demonstrate that the laser dose used for introducing DNA damage determines the repertoire of DNA repair proteins recruited. Furthermore, we demonstrate that recruitment of POLß and PNK to regions irradiated with low laser dose requires XRCC1 and that inhibition of PARylation by PARP......-inhibitors only slightly reduces the recruitment of XRCC1, PNK, or POLß to sites of DNA damage. Recruitment of PCNA and FEN-1 requires higher doses of irradiation and is enhanced by XRCC1, as well as by accumulation of PARP-1 at the site of DNA damage. These data improve our understanding of recruitment of BER......XRCC1 is a scaffold protein capable of interacting with several DNA repair proteins. Here we provide evidence for the presence of XRCC1 in different complexes of sizes from 200 to 1500 kDa, and we show that immunoprecipitates using XRCC1 as bait are capable of complete repair of AP sites via both...

  11. Mobile phone radiation induces mode-dependent DNA damage in a mouse spermatocyte-derived cell line: a protective role of melatonin.

    Science.gov (United States)

    Liu, Chuan; Gao, Peng; Xu, Shang-Cheng; Wang, Yuan; Chen, Chun-Hai; He, Min-Di; Yu, Zheng-Ping; Zhang, Lei; Zhou, Zhou

    2013-11-01

    To evaluate whether exposure to mobile phone radiation (MPR) can induce DNA damage in male germ cells. A mouse spermatocyte-derived GC-2 cell line was exposed to a commercial mobile phone handset once every 20 min in standby, listen, dialed or dialing modes for 24 h. DNA damage was determined using an alkaline comet assay. The levels of DNA damage were significantly increased following exposure to MPR in the listen, dialed and dialing modes. Moreover, there were significantly higher increases in the dialed and dialing modes than in the listen mode. Interestingly, these results were consistent with the radiation intensities of these modes. However, the DNA damage effects of MPR in the dialing mode were efficiently attenuated by melatonin pretreatment. These results regarding mode-dependent DNA damage have important implications for the safety of inappropriate mobile phone use by males of reproductive age and also suggest a simple preventive measure: Keeping mobile phones as far away from our body as possible, not only during conversations but during 'dialed' and 'dialing' operation modes. Since the 'dialed' mode is actually part of the standby mode, mobile phones should be kept at a safe distance from our body even during standby operation. Furthermore, the protective role of melatonin suggests that it may be a promising pharmacological candidate for preventing mobile phone use-related reproductive impairments.

  12. DNA damaging bystander signalling from stem cells, cancer cells and fibroblasts after Cr(VI) exposure and its dependence on telomerase

    Energy Technology Data Exchange (ETDEWEB)

    Cogan, Nicola [Bristol Implant Research Centre, University of Bristol, Bristol, BS10 5NB (United Kingdom); Baird, Duncan M. [Department of Pathology School of Medicine, Cardiff University, Henry Wellcome Building for Biomedical Research in Wales, Heath Park, Cardiff, CF14 4XN (United Kingdom); Phillips, Ryan [Bristol Implant Research Centre, University of Bristol, Bristol, BS10 5NB (United Kingdom); Crompton, Lucy A.; Caldwell, Maeve A. [Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, BS1 3NY (United Kingdom); Rubio, Miguel A. [Center of Regenerative Medicine in Barcelona, CMRB Dr. Aiguader, 88, 7th Floor, 08003 Barcelona (Spain); Newson, Roger [Radiation and Environmental Science Centre, Focas Institute, Dublin Institute of Technology, Dublin 2 (Ireland); Lyng, Fiona [National Heart and Lung Institute, Imperial College London, London, SW7 2AZ (United Kingdom); Case, C. Patrick, E-mail: c.p.case@bristol.ac.uk [Bristol Implant Research Centre, University of Bristol, Bristol, BS10 5NB (United Kingdom)

    2010-01-05

    The bystander effect is a feature of low dose radiation exposure and is characterized by a signaling process from irradiated cells to non irradiated cells, which causes DNA and chromosome damage in these 'nearest neighbour' cells. Here we show that a low and short dose of Cr(VI) can induce stem cells, cancer cells and fibroblasts to chronically secrete bystander signals, which cause DNA damage in neighboring cells. The Cr(VI) induced bystander signaling depended on the telomerase status of either cell. Telomerase negative fibroblasts were able to receive DNA damaging signals from telomerase positive or negative fibroblasts or telomerase positive cancer cells. However telomerase positive fibroblasts were resistant to signals from Cr(VI) exposed telomerase positive fibroblasts or cancer cells. Human embryonic stem cells, with positive Oct4 staining as a marker of pluripotency, showed no significant increase of DNA damage from adjacent Cr and mitomycin C exposed fibroblasts whilst those cells that were negatively stained did. This selectivity of DNA damaging bystander signaling could be an important consideration in developing therapies against cancer and in the safety and effectiveness of tissue engineering and transplantation using stem cells.

  13. DNA damaging bystander signalling from stem cells, cancer cells and fibroblasts after Cr(VI) exposure and its dependence on telomerase

    International Nuclear Information System (INIS)

    Cogan, Nicola; Baird, Duncan M.; Phillips, Ryan; Crompton, Lucy A.; Caldwell, Maeve A.; Rubio, Miguel A.; Newson, Roger; Lyng, Fiona; Case, C. Patrick

    2010-01-01

    The bystander effect is a feature of low dose radiation exposure and is characterized by a signaling process from irradiated cells to non irradiated cells, which causes DNA and chromosome damage in these 'nearest neighbour' cells. Here we show that a low and short dose of Cr(VI) can induce stem cells, cancer cells and fibroblasts to chronically secrete bystander signals, which cause DNA damage in neighboring cells. The Cr(VI) induced bystander signaling depended on the telomerase status of either cell. Telomerase negative fibroblasts were able to receive DNA damaging signals from telomerase positive or negative fibroblasts or telomerase positive cancer cells. However telomerase positive fibroblasts were resistant to signals from Cr(VI) exposed telomerase positive fibroblasts or cancer cells. Human embryonic stem cells, with positive Oct4 staining as a marker of pluripotency, showed no significant increase of DNA damage from adjacent Cr and mitomycin C exposed fibroblasts whilst those cells that were negatively stained did. This selectivity of DNA damaging bystander signaling could be an important consideration in developing therapies against cancer and in the safety and effectiveness of tissue engineering and transplantation using stem cells.

  14. Protease activity of PprI facilitates DNA damage response: Mn2+-dependence and substrate sequence-specificity of the proteolytic reaction.

    Directory of Open Access Journals (Sweden)

    Yunguang Wang

    Full Text Available The extremophilic bacterium Deinococcus radiodurans exhibits an extraordinary resistance to ionizing radiation. Previous studies established that a protein named PprI, which exists only in the Deinococcus-Thermus family, acts as a general switch to orchestrate the expression of a number of DNA damage response (DDR proteins involved in cellular radio-resistance. Here we show that the regulatory mechanism of PprI depends on its Mn(2+-dependent protease activity toward DdrO, a transcription factor that suppresses DDR genes' expression. Recognition sequence-specificity around the PprI cleavage site is essential for DNA damage repair in vivo. PprI and DdrO mediate a novel DNA damage response pathway differing from the classic LexA-mediated SOS response system found in radiation-sensitive bacterium Escherichia coli. This PprI-mediated pathway in D. radiodurans is indispensable for its extreme radio-resistance and therefore its elucidation significantly advances our understanding of the DNA damage repair mechanism in this amazing organism.

  15. Nucleosome acidic patch promotes RNF168- and RING1B/BMI1-dependent H2AX and H2A ubiquitination and DNA damage signaling.

    Directory of Open Access Journals (Sweden)

    Justin W Leung

    2014-03-01

    Full Text Available Histone ubiquitinations are critical for the activation of the DNA damage response (DDR. In particular, RNF168 and RING1B/BMI1 function in the DDR by ubiquitinating H2A/H2AX on Lys-13/15 and Lys-118/119, respectively. However, it remains to be defined how the ubiquitin pathway engages chromatin to provide regulation of ubiquitin targeting of specific histone residues. Here we identify the nucleosome acid patch as a critical chromatin mediator of H2A/H2AX ubiquitination (ub. The acidic patch is required for RNF168- and RING1B/BMI1-dependent H2A/H2AXub in vivo. The acidic patch functions within the nucleosome as nucleosomes containing a mutated acidic patch exhibit defective H2A/H2AXub by RNF168 and RING1B/BMI1 in vitro. Furthermore, direct perturbation of the nucleosome acidic patch in vivo by the expression of an engineered acidic patch interacting viral peptide, LANA, results in defective H2AXub and RNF168-dependent DNA damage responses including 53BP1 and BRCA1 recruitment to DNA damage. The acidic patch therefore is a critical nucleosome feature that may serve as a scaffold to integrate multiple ubiquitin signals on chromatin to compose selective ubiquitinations on histones for DNA damage signaling.

  16. The Aurora-B-dependent NoCut checkpoint prevents damage of anaphase bridges after DNA replication stress.

    Science.gov (United States)

    Amaral, Nuno; Vendrell, Alexandre; Funaya, Charlotta; Idrissi, Fatima-Zahra; Maier, Michael; Kumar, Arun; Neurohr, Gabriel; Colomina, Neus; Torres-Rosell, Jordi; Geli, María-Isabel; Mendoza, Manuel

    2016-05-01

    Anaphase chromatin bridges can lead to chromosome breakage if not properly resolved before completion of cytokinesis. The NoCut checkpoint, which depends on Aurora B at the spindle midzone, delays abscission in response to chromosome segregation defects in yeast and animal cells. How chromatin bridges are detected, and whether abscission inhibition prevents their damage, remain key unresolved questions. We find that bridges induced by DNA replication stress and by condensation or decatenation defects, but not dicentric chromosomes, delay abscission in a NoCut-dependent manner. Decatenation and condensation defects lead to spindle stabilization during cytokinesis, allowing bridge detection by Aurora B. NoCut does not prevent DNA damage following condensin or topoisomerase II inactivation; however, it protects anaphase bridges and promotes cellular viability after replication stress. Therefore, the molecular origin of chromatin bridges is critical for activation of NoCut, which plays a key role in the maintenance of genome stability after replicative stress.

  17. Inhibition of polo-like kinase-1 by DNA damage occurs in an ATM- or ATR-dependent fashion

    NARCIS (Netherlands)

    van Vugt, MATM; Smits, VAJ; Klompmaker, R; Medema, RH

    2001-01-01

    Polo-like kinases play multiple roles in different phases of mitosis. We have recently shown that the mammalian polo-like kinase, Plk1, is inhibited in response to DNA damage and that this inhibition may lead to cell cycle arrests at multiple points in mitosis. Here we have investigated the role of

  18. Changes in properties of DNA caused by gamma and ultraviolet radiation. Dependence of conformational changes on the chemical nature of the damage

    Energy Technology Data Exchange (ETDEWEB)

    Vorlickova, M; Palacek, E [Ceskoslovenska Akademie Ved, Brno. Biofysikalni Ustav

    1978-02-16

    Changes in the pulse-polarographic behaviour and circular dichroism spectra of DNA were investigated after gamma and ultraviolet irradiations and after degradation by DNAase I. It was found that moderate doses of radiation cause local conformational changes in the double helix which are dependent on the chemical nature of the damage. Only the accumulation of structural changes after high doses of the radiations or after extensive enzymic treatment may cause formation of single-standed regions in DNA.

  19. Evidence for an age-dependent influence of environmental variations on a long-lived seabird's life-history traits.

    Science.gov (United States)

    Pardo, Deborah; Barbraud, Christophe; Authier, Matthieu; Weimerskirch, Henri

    2013-01-01

    Theoretical and empirical studies have highlighted the effects of age on several life-history traits in wild populations. There is also increasing evidence for environmental effects on their demographic traits. However, quantifying how individuals differentially respond to environmental variations according to their age remains a challenge in ecology. In a population of Black-browed Albatrosses monitored during 43 years, we analyzed how life-history traits varied according to age, and whether individuals of different ages responded in different ways to environmental conditions. To do so, we: (1) examined how age affected seven life-history traits, (2) investigated differences in temporal variance of demographic traits between age classes, and (3) tested for age-dependent effects of climate and fisheries covariates on demographic traits. Overall, there was a tendency for traits to improve during the first years of life (5-10 years), to peak and remain stable at middle age (10-30 years), and decline at old ages. At young ages, survival and reproductive parameters increased, except offspring body condition at fledging, suggesting that younger parents had already acquired good foraging capacities. However, they suffered from inexperience in breeding as suggested by their higher breeding failures during incubation. There was evidence for reproductive and actuarial senescence. In particular, breeding success and offspring body condition declined abruptly, suggesting altered foraging capacities of old individuals. Middle-aged individuals had the lowest temporal variance of demographic traits. Although this is predicted by the theory of environmental canalization, it could also results from a higher susceptibility of young and old birds due to their respective inexperience and senescence. The highest temporal variances were found in old individuals. Survival was significantly influenced by sea surface temperatures in the foraging zone of this albatross population during

  20. Damage and failure processes in structural materials

    International Nuclear Information System (INIS)

    Embury, J.D.

    1993-01-01

    At large plastic strains consideration must be given not only to the descriptions of work hardening and texture evolution but also to the process of damage accumulation and the documentation of the various modes of failure which may terminate the plastic history. In this presentation consideration is given first to documenting the various modes of failure and their dependence on stress state. It is then shown that damage accumulation can be studied in a quantitative manner by using model systems in conjunction with FEM calculations. Finally consideration is given to complex forming processes such as ironing to show how studies of damage initiation and accumulation relate to practical engineering problems. (orig.)

  1. Temperature dependence on plasma-induced damage and chemical reactions in GaN etching processes using chlorine plasma

    Science.gov (United States)

    Liu, Zecheng; Ishikawa, Kenji; Imamura, Masato; Tsutsumi, Takayoshi; Kondo, Hiroki; Oda, Osamu; Sekine, Makoto; Hori, Masaru

    2018-06-01

    Plasma-induced damage (PID) on GaN was optimally reduced by high-temperature chlorine plasma etching. Energetic ion bombardments primarily induced PID involving stoichiometry, surface roughness, and photoluminescence (PL) degradation. Chemical reactions under ultraviolet (UV) irradiation and chlorine radical exposure at temperatures higher than 400 °C can be controlled by taking into account the synergism of simultaneous photon and radical irradiations to effectively reduce PID.

  2. Targeted Delivery of Neutralizing Anti-C5 Antibody to Renal Endothelium Prevents Complement-Dependent Tissue Damage

    Directory of Open Access Journals (Sweden)

    Paolo Durigutto

    2017-09-01

    Full Text Available Complement activation is largely implicated in the pathogenesis of several clinical conditions and its therapeutic neutralization has proven effective in preventing tissue and organ damage. A problem that still needs to be solved in the therapeutic control of complement-mediated diseases is how to avoid side effects associated with chronic neutralization of the complement system, in particular, the increased risk of infections. We addressed this issue developing a strategy based on the preferential delivery of a C5 complement inhibitor to the organ involved in the pathologic process. To this end, we generated Ergidina, a neutralizing recombinant anti-C5 human antibody coupled with a cyclic-RGD peptide, with a distinctive homing property for ischemic endothelial cells and effective in controlling tissue damage in a rat model of renal ischemia/reperfusion injury (IRI. As a result of its preferential localization on renal endothelium, the molecule induced complete inhibition of complement activation at tissue level, and local protection from complement-mediated tissue damage without affecting circulating C5. The ex vivo binding of Ergidina to surgically removed kidney exposed to cold ischemia supports its therapeutic use to prevent posttransplant IRI leading to delay of graft function. Moreover, the finding that the ex vivo binding of Ergidina was not restricted to the kidney, but was also seen on ischemic heart, suggests that this RGD-targeted anti-C5 antibody may represent a useful tool to treat organs prior to transplantation. Based on this evidence, we propose preliminary data showing that Ergidina is a novel targeted drug to prevent complement activation on the endothelium of ischemic kidney.

  3. LET dependence of linear and quadratic terms in dose-response relationships for cellular damage: correlations with the dimensions and structures of biological targets

    International Nuclear Information System (INIS)

    Barendsen, G.W.; Amsterdam Univ.

    1990-01-01

    To apply information from microdosimetric studies and from cellular responses to the development and testing of hypotheses about mechanisms of radiation action, it is necessary to correlate these data with insights concerning dimensions and structures of cellular constituents and macromolecules. This approach is illustrated by the correlation of cross sections for inactivation with dimensions of the cell nucleus in dependence on the culture conditions and by the comparison of the derived dimensions of critical targets with DNA packing and chromatin structure in cells. A model is suggested in which lethal and potentially lethal damage induced in mammalian cells by single ionising particles involves the induction of two DNA double strand breaks in close proximity in a chromatin fibre, while accumulation of damage causing the contribution, which increases with the square of the dose, might be associated with interaction of single DSBs produced at larger distances. (author)

  4. Oxidative damage mediated iNOS and UCP-2 upregulation in rat brain after sub-acute cyanide exposure: dose and time-dependent effects.

    Science.gov (United States)

    Bhattacharya, Rahul; Singh, Poonam; John, Jebin Jacob; Gujar, Niranjan L

    2018-04-03

    Cyanide-induced chemical hypoxia is responsible for pronounced oxidative damage in the central nervous system. The disruption of mitochondrial oxidative metabolism has been associated with upregulation of uncoupling proteins (UCPs). The present study addresses the dose- and time-dependent effect of sub-acute cyanide exposure on various non-enzymatic and enzymatic oxidative stress markers and their correlation with inducible-nitric oxide synthase (iNOS) and uncoupling protein-2 (UCP-2) expression. Animals received (oral) triple distilled water (vehicle control), 0.25 LD50 potassium cyanide (KCN) or 0.50 LD50 KCN daily for 21 d. Animals were sacrificed on 7, 14 and 21 d post-exposure to measure serum cyanide and nitrite, and brain malondialdehyde (MDA), reduced glutathione (GSH), glutathione disulfide (GSSG), cytochrome c oxidase (CCO), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR) and catalase (CA) levels, together with iNOS and UCP-2 expression, and DNA damage. The study revealed that a dose- and time-dependent increase in cyanide concentration was accompanied by corresponding CCO inhibition and elevated MDA levels. Decrease in GSH levels was not followed by reciprocal change in GSSG levels. Diminution of SOD, GPx, GR and CA activity was congruent with elevated nitrite levels and upregulation of iNOS and UCP-2 expression, without any DNA damage. It was concluded that long-term cyanide exposure caused oxidative stress, accompanied by upregulation of iNOS. The upregulation of UCP-2 further sensitized the cells to cyanide and accentuated the oxidative stress, which was independent of DNA damage.

  5. NOX4-dependent neuronal autotoxicity and BBB breakdown explain the superior sensitivity of the brain to ischemic damage.

    Science.gov (United States)

    Casas, Ana I; Geuss, Eva; Kleikers, Pamela W M; Mencl, Stine; Herrmann, Alexander M; Buendia, Izaskun; Egea, Javier; Meuth, Sven G; Lopez, Manuela G; Kleinschnitz, Christoph; Schmidt, Harald H H W

    2017-11-14

    Ischemic injury represents the most frequent cause of death and disability, and it remains unclear why, of all body organs, the brain is most sensitive to hypoxia. In many tissues, type 4 NADPH oxidase is induced upon ischemia or hypoxia, converting oxygen to reactive oxygen species. Here, we show in mouse models of ischemia in the heart, brain, and hindlimb that only in the brain does NADPH oxidase 4 (NOX4) lead to ischemic damage. We explain this distinct cellular distribution pattern through cell-specific knockouts. Endothelial NOX4 breaks down the BBB, while neuronal NOX4 leads to neuronal autotoxicity. Vascular smooth muscle NOX4, the common denominator of ischemia within all ischemic organs, played no apparent role. The direct neuroprotective potential of pharmacological NOX4 inhibition was confirmed in an ex vivo model, free of vascular and BBB components. Our results demonstrate that the heightened sensitivity of the brain to ischemic damage is due to an organ-specific role of NOX4 in blood-brain-barrier endothelial cells and neurons. This mechanism is conserved in at least two rodents and humans, making NOX4 a prime target for a first-in-class mechanism-based, cytoprotective therapy in the unmet high medical need indication of ischemic stroke. Copyright © 2017 the Author(s). Published by PNAS.

  6. Characterizing and modeling the pressure- and rate-dependent elastic-plastic-damage behaviors of polypropylene-based polymers

    KAUST Repository

    Pulungan, Ditho Ardiansyah; Yudhanto, Arief; Goutham, Shiva; Lubineau, Gilles; Yaldiz, Recep; Schijve, Warden

    2018-01-01

    Polymers in general exhibit pressure- and rate-dependent behavior. Modeling such behavior requires extensive, costly and time-consuming experimental work. Common simplifications may lead to severe inaccuracy when using the model for predicting

  7. Life history traits influence the strength of distance- and density-dependence at different life stages of two Amazonian palms.

    Science.gov (United States)

    Choo, Juanita; Carasco, Cecilia; Alvarez-Loayza, Patricia; Simpson, Beryl B; Economo, Evan P

    2017-07-01

    Natural enemies are known to be important in regulating plant populations and contributing to species coexistence (Janzen-Connell effects). The strength of Janzen-Connell effects (both distance- and density-effects) varies across species, but the life history traits that may mediate such a variation are not well understood. This study examined Janzen-Connell effects across the life stages (seed through adult stages) of two sympatric palm species with distinct phenologies and shade tolerances, two traits that may mediate the strength and timing of Janzen-Connell effects. Populations of two common palm species, Attalea phalerata and Astrocaryum murumuru , were studied in Manu National Park, Peru. Seed predation experiments were conducted to assess Janzen-Connell effects at the seed stage. In the post-seed stages, spatial point pattern analyses of the distributions of individuals and biomass were used to infer the strength of distance- and density-effects. Seed predation was both negative distance- and density-dependent consistent with the Janzen-Connell effects. However, only seedling recruitment for asynchronously fruiting Attalea phalerata was depressed near adults while recruitment remained high for synchronously fruiting Astrocaryum murumuru , consistent with weak distance-effects. Negative density-effects were strong in the early stages for shade-intolerant Attalea phalerata but weak or absent in shade-tolerant Astrocaryum murumuru. Distance- and density-effects varied among the life stages of the two palm species in a manner that corresponded to their contrasting phenology and shade tolerance. Generalizing such connections across many species would provide a route to understanding how trait-mediated Janzen-Connell effects scale up to whole communities of species. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  8. Learning from history : Changes and path dependency in the social housing sector in Austria, France and the Netherlands (1889-2008), Chapter 3

    NARCIS (Netherlands)

    Lévy-Vroelant, C.; Reinprecht, C.; Wassenberg, F.

    2008-01-01

    European social housing history can be interpreted through the combination of two complementary notions: path dependency and change. Socio-political experiences and practices at the national, regional or municipal level are potentially powerful determinants of historical developments—an idea known

  9. Cellular and molecular repair of X-ray-induced damage: dependence on oxygen tension and nutritional status

    International Nuclear Information System (INIS)

    Spiro, I.J.; Kennedy, K.A.; Stickler, R.; Ling, C.C.

    1985-01-01

    Cellular and molecular repair was studied at 23 0 C using split-dose recovery and alkaline elution techniques, respectively, as a function of cellular oxygen and nutrient conditions. Hypoxic cells in full medium showed a partial reduction in the level of sublethal damage (SLD) repair relative to aerated cells; the respective repair kinetics were similar with a common repair half-time of 30 min. Similarly, hypoxic cells showed a slight reduction in strand break rejoining capacity compared to aerated cells. Under nutrient deprivation, anoxic cells displayed no SLD repair or strand break repair, while aerated cells exhibited the same level of SLD and strand break repair as for well-fed cells. In addition, nutrient deprived cells at low O 2 levels displayed normal SLD and strand break repair capability. These results indicate that both nutrient and O 2 deprivation are necessary for complete inhibition of cellular and molecular repair, and low levels of O 2 can effectively reverse this inhibition

  10. Histories electromagnetism

    International Nuclear Information System (INIS)

    Burch, Aidan

    2004-01-01

    Working within the HPO (History Projection Operator) Consistent Histories formalism, we follow the work of Savvidou on (scalar) field theory [J. Math. Phys. 43, 3053 (2002)] and that of Savvidou and Anastopoulos on (first-class) constrained systems [Class. Quantum Gravt. 17, 2463 (2000)] to write a histories theory (both classical and quantum) of Electromagnetism. We focus particularly on the foliation-dependence of the histories phase space/Hilbert space and the action thereon of the two Poincare groups that arise in histories field theory. We quantize in the spirit of the Dirac scheme for constrained systems

  11. Modeling of DNA damage-cluster, cell-cycle and repair pathway dependent radiosensitivity after low- and high-LET irradiation

    International Nuclear Information System (INIS)

    Guenther, Paul

    2017-01-01

    This work focuses on modeling of the effects of ionizing radiation on cells, primarily on, the influence of the DNA repair pathway availability and the radiation quality on the cell-survival probability. The availability of DNA repair pathways depends on the replication state and defects of the DNA repair pathways. The radiation quality manifests itself in the microscopic ionization pattern. The Giant LOop Binary LEsion (GLOBLE) model and the Local Effect Model (LEM) describe the cell-survival after photon and ion irradiation, respectively. Both models assume that cell survival can be modeled based on the spatial distribution of Double-Strand Breaks (DSB) of the DNA (damage pattern), within a higher order chromatin structure. Single DSB are referred to as isolated DSB (iDSB) and two or more DSB in close proximity (within 540 nm) are called complex DSB (cDSB). In order to predict the cell-survival, the GLOBLE-Model considers different iDSB repair-pathways and their availability. One central assumption of the LEM is that the same damage patterns imply same effects, regardless of the radiation quality. In order to predict the damage pattern the microscopic local dose distribution of ions, described by the amorphous track structure, is evaluated. The cell survival after ion irradiation is predicted from a comparison with corresponding damage patterns after photon irradiation. The cell-survival curves after high dose photon irradiation cannot be predicted from the Linear Quadratic (LQ) Model due to their transition towards a linear dose dependence. This work uses the GLOBLE-Model to introduce a novel mechanistic approach, which allows the threshold dose to be predicted for the transition from a linear quadratic dose dependence, of survival curves at low doses, to a linear dose dependence at high doses. Furthermore, a method is presented, which allows LEM to predict the survival of synchronous cells after ion irradiation based on the cell survival after photon

  12. PRMT1 and PRMT4 Regulate Oxidative Stress-Induced Retinal Pigment Epithelial Cell Damage in SIRT1-Dependent and SIRT1-Independent Manners

    Directory of Open Access Journals (Sweden)

    Dong-Il Kim

    2015-01-01

    Full Text Available Oxidative stress-induced retinal pigment epithelial (RPE cell damage is involved in the progression of diabetic retinopathy. Arginine methylation catalyzed by protein arginine methyltransferases (PRMTs has emerged as an important histone modification involved in diverse diseases. Sirtuin (SIRT1 is a protein deacetylase implicated in the onset of metabolic diseases. Therefore, we examined the roles of type I PRMTs and their relationship with SIRT1 in human RPE cells under H2O2-induced oxidative stress. H2O2 treatment increased PRMT1 and PRMT4 expression but decreased SIRT1 expression. Similar to H2O2 treatment, PRMT1 or PRMT4 overexpression increased RPE cell damage. Moreover, the H2O2-induced RPE cell damage was attenuated by PRMT1 or PRMT4 knockdown and SIRT1 overexpression. In this study, we revealed that SIRT1 expression was regulated by PRMT1 but not by PRMT4. Finally, we found that PRMT1 and PRMT4 expression is increased in the RPE layer of streptozotocin-treated rats. Taken together, we demonstrated that oxidative stress induces apoptosis both via PRMT1 in a SIRT1-dependent manner and via PRMT4 in a SIRT1-independent manner. The inhibition of the expression of type I PRMTs, especially PRMT1 and PRMT4, and increased SIRT1 could be therapeutic approaches for diabetic retinopathy.

  13. Berberine induces p53-dependent cell cycle arrest and apoptosis of human osteosarcoma cells by inflicting DNA damage

    International Nuclear Information System (INIS)

    Liu Zhaojian; Liu Qiao; Xu Bing; Wu Jingjing; Guo Chun; Zhu Faliang; Yang Qiaozi; Gao Guimin; Gong Yaoqin; Shao Changshun

    2009-01-01

    Alkaloid berberine is widely used for the treatment of diarrhea and other diseases. Many laboratory studies showed that it exhibits anti-proliferative activity against a wide spectrum of cancer cells in culture. In this report we studied the mechanisms underlying the inhibitory effects of berberine on human osteosarcoma cells and on normal osteoblasts. The inhibition was largely attributed to cell cycle arrest at G1 and G2/M, and to a less extent, to apoptosis. The G1 arrest was dependent on p53, as G1 arrest was abolished in p53-deficient osteosarcoma cells. The induction of G1 arrest and apoptosis was accompanied by a p53-dependent up-regulation of p21 and pro-apoptotic genes. However, the G2/M arrest could be induced by berberine regardless of the status of p53. Interestingly, DNA double-strand breaks, as measured by the phosphorylation of H2AX, were remarkably accumulated in berberine-treated cells in a dose-dependent manner. Thus, one major mechanism by which berberine exerts its growth-inhibitory effect is to inflict genomic lesions on cells, which in turn trigger the activation of p53 and the p53-dependent cellular responses including cell cycle arrest and apoptosis

  14. Berberine induces p53-dependent cell cycle arrest and apoptosis of human osteosarcoma cells by inflicting DNA damage

    Energy Technology Data Exchange (ETDEWEB)

    Liu Zhaojian; Liu Qiao; Xu Bing; Wu Jingjing [Key Laboratory of Experimental Teratology of Ministry of Education and Institute of Molecular Medicine and Genetics, Shandong University School of Medicine, Jinan, Shandong 250012 (China); Guo Chun; Zhu Faliang [Institute of Immunology, Shandong University School of Medicine, Jinan, Shandong 250012 (China); Yang Qiaozi [Department of Genetics, Rutgers University, Piscataway, NJ 08854 (United States); Gao Guimin [Key Laboratory of Experimental Teratology of Ministry of Education and Institute of Molecular Medicine and Genetics, Shandong University School of Medicine, Jinan, Shandong 250012 (China); Gong Yaoqin [Key Laboratory of Experimental Teratology of Ministry of Education and Institute of Molecular Medicine and Genetics, Shandong University School of Medicine, Jinan, Shandong 250012 (China)], E-mail: yxg8@sdu.edu.cn; Shao Changshun [Key Laboratory of Experimental Teratology of Ministry of Education and Institute of Molecular Medicine and Genetics, Shandong University School of Medicine, Jinan, Shandong 250012 (China); Department of Genetics, Rutgers University, Piscataway, NJ 08854 (United States)], E-mail: shao@biology.rutgers.edu

    2009-03-09

    Alkaloid berberine is widely used for the treatment of diarrhea and other diseases. Many laboratory studies showed that it exhibits anti-proliferative activity against a wide spectrum of cancer cells in culture. In this report we studied the mechanisms underlying the inhibitory effects of berberine on human osteosarcoma cells and on normal osteoblasts. The inhibition was largely attributed to cell cycle arrest at G1 and G2/M, and to a less extent, to apoptosis. The G1 arrest was dependent on p53, as G1 arrest was abolished in p53-deficient osteosarcoma cells. The induction of G1 arrest and apoptosis was accompanied by a p53-dependent up-regulation of p21 and pro-apoptotic genes. However, the G2/M arrest could be induced by berberine regardless of the status of p53. Interestingly, DNA double-strand breaks, as measured by the phosphorylation of H2AX, were remarkably accumulated in berberine-treated cells in a dose-dependent manner. Thus, one major mechanism by which berberine exerts its growth-inhibitory effect is to inflict genomic lesions on cells, which in turn trigger the activation of p53 and the p53-dependent cellular responses including cell cycle arrest and apoptosis.

  15. Hydrogen peroxide-induced DNA damage is independent of nuclear calcium but dependent on redox-active ions.

    Science.gov (United States)

    Jornot, L; Petersen, H; Junod, A F

    1998-01-01

    In cells undergoing oxidative stress, DNA damage may result from attack by .OH radicals produced by the Fenton reaction, and/or by nucleases activated by nuclear calcium. In the present study, the participation of these two mechanisms was investigated in HeLa cells. Nuclear-targeted aequorin was used for selectively monitoring Ca2+ concentrations within the nuclei ([Ca2+]n), in conjunction with the cell-permeant calcium chelator bis-(o-aminophenoxy)ethane-N,N,N', N'-tetraacetic acid acetoxymethyl ester (BAPTA/AM), the lipid-soluble broad-spectrum metal chelator with low affinity for Ca2+ and Mg2+ N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), and the high-affinity iron/copper chelator 1, 10-phenanthroline (PHE). In Ca2+-containing medium, H2O2 induced extensive DNA strand breaks and an increase in [Ca2+]n that was almost identical to that observed in the cytosol ([Ca2+]c). In cells bathed in Ca2+-free/EGTA medium, in which the increases in [Ca2+]n and [Ca2+]c due to H2O2 were significantly reduced, similar levels of DNA fragmentation also occurred. In cells preloaded with BAPTA/AM or TPEN, the small increase of [Ca2+]n normally elicited by H2O2 in Ca2+-free medium was completely buffered, and DNA damage was largely prevented. On the other hand, pretreatment with PHE did not affect the calcium response in the nuclei, but completely prevented DNA strand breakage induced by H2O2. Re-addition of 100 microM CuSO4 and 100 microM FeSO4 to TPEN- and PHE-treated cells prior to H2O2 challenge reversed the effect of TPEN and PHE, whereas 1 mM was necessary to negate the effect of BAPTA/AM. The levels of DNA strand breakage observed, however, did not correlate with the amounts of 8-hydroxy 2'-deoxyguanosine (8-OHdG): H2O2 did not produce 8-OHdG, whereas PHE alone slightly increased 8-OHdG levels. CuSO4 and FeSO4 enhanced the effects of PHE, particularly in the presence of H2O2. Exposure of cells to a mixture of CuSO4/FeSO4 also resulted in a significant increase in

  16. Molecular profiling of fungal communities in moisture damaged buildings before and after remediation--a comparison of culture-dependent and culture-independent methods.

    Science.gov (United States)

    Pitkäranta, Miia; Meklin, Teija; Hyvärinen, Anne; Nevalainen, Aino; Paulin, Lars; Auvinen, Petri; Lignell, Ulla; Rintala, Helena

    2011-10-21

    Indoor microbial contamination due to excess moisture is an important contributor to human illness in both residential and occupational settings. However, the census of microorganisms in the indoor environment is limited by the use of selective, culture-based detection techniques. By using clone library sequencing of full-length internal transcribed spacer region combined with quantitative polymerase chain reaction (qPCR) for 69 fungal species or assay groups and cultivation, we have been able to generate a more comprehensive description of the total indoor mycoflora. Using this suite of methods, we assessed the impact of moisture damage on the fungal community composition of settled dust and building material samples (n = 8 and 16, correspondingly). Water-damaged buildings (n = 2) were examined pre- and post- remediation, and compared with undamaged reference buildings (n = 2). Culture-dependent and independent methods were consistent in the dominant fungal taxa in dust, but sequencing revealed a five to ten times higher diversity at the genus level than culture or qPCR. Previously unknown, verified fungal phylotypes were detected in dust, accounting for 12% of all diversity. Fungal diversity, especially within classes Dothideomycetes and Agaricomycetes tended to be higher in the water damaged buildings. Fungal phylotypes detected in building materials were present in dust samples, but their proportion of total fungi was similar for damaged and reference buildings. The quantitative correlation between clone library phylotype frequencies and qPCR counts was moderate (r = 0.59, p environments. However, making conclusions concerning the effect of building conditions on building mycobiota using this methodology was complicated by the wide natural diversity in the dust samples, the incomplete knowledge of material-associated fungi fungi and the semiquantitative nature of sequencing based methods.

  17. On Regularly Varying and History-Dependent Convergence Rates of Solutions of a Volterra Equation with Infinite Memory

    OpenAIRE

    John A. D. Appleby

    2010-01-01

    We consider the rate of convergence to equilibrium of Volterra integrodifferential equations with infinite memory. We show that if the kernel of Volterra operator is regularly varying at infinity, and the initial history is regularly varying at minus infinity, then the rate of convergence to the equilibrium is regularly varying at infinity, and the exact pointwise rate of convergence can be determined in terms of the rate of decay of the kernel and the rate of growth of the initial history. ...

  18. Poly(ADP-ribosyl)ation links the chromatin remodeler SMARCA5/SNF2H to RNF168-dependent DNA damage signaling

    DEFF Research Database (Denmark)

    Smeenk, G.; Wiegant, W.W.; Luijsterburg, M.S.

    2013-01-01

    Ionizing radiation (IR)-induced DNA double-strand breaks (DSBs) arising in native chromatin elicit an RNF8/RNF168-dependent ubiquitylation response, which triggers the recruitment of various repair factors. Precisely how this response is regulated in the context of chromatin remains largely...... unexplored. Here, we show that SMARCA5/SNF2H, the catalytic subunit of ISWI chromatin remodeling complexes, is recruited to DSBs in a poly(ADP-ribose) polymerase 1 (PARP1)-dependent manner. Remarkably, PARP activity, although dispensable for the efficient spreading of νH2AX into damaged chromatin......, selectively promotes spreading of SMARCA5, the E3 ubiquitin ligase RNF168, ubiquitin conjugates and the ubiquitin-binding factors RAD18 and the RAP80-BRCA1 complex throughout DSB-flanking chromatin. This suggests that PARP regulates the spatial organization of the RNF168-driven ubiquitin response to DNA...

  19. Damage to Broca’s area OR the anterior temporal lobe is implicated in stroke-induced agrammatic comprehension: it depends on the task

    Directory of Open Access Journals (Sweden)

    Corianne Rogalsky

    2015-04-01

    comprehension in each task. Agrammatic comprehension was indexed as the difference in performance of each patient between subject relative and object relative sentences. VLSMs using these indices identified that agrammatic comprehension in each task was associated with damage to different brain regions: In the sentence-picture matching task, agrammatic comprehension was associated with damage in the left putamen, external capsule and adjacent white matter underlying the left inferior frontal gyrus and left precentral gyrus. Conversely in the plausibility judgment task, agrammatic comprehension was associated with damage in the left anterior superior temporal gyrus. Thus agrammatic comprehension indexed using different tasks localized to different lesion patterns. Our findings suggest that the neurobiology of agrammatic comprehension is task-dependent. These results also provide possible neural bases for the behavioral dissociations between sentence comprehension and grammaticality judgment impairments that have been reported in patients with aphasia (Linebarger et al. 1983; Wulfeck, 1988, although grammaticality and plausibility judgments are certainly different computational tasks.

  20. The roles of DNA damage-dependent signals and MAPK cascades in tributyltin-induced germline apoptosis in Caenorhabditis elegans.

    Science.gov (United States)

    Wang, Yun; Wang, Shunchang; Luo, Xun; Yang, Yanan; Jian, Fenglei; Wang, Xuemin; Xie, Lucheng

    2014-08-01

    The induction of apoptosis is recognized to be a major mechanism of tributyltin (TBT) toxicity. However, the underlying signaling pathways for TBT-induced apoptosis remain unclear. In this study, using the nematode Caenorhabditis elegans, we examined whether DNA damage response (DDR) pathway and mitogen-activated protein kinase (MAPK) signaling cascades are involved in TBT-induced germline apoptosis and cell cycle arrest. Our results demonstrated that exposing worms to TBT at the dose of 10nM for 6h significantly increased germline apoptosis in N2 strain. Germline apoptosis was absent in strains that carried ced-3 or ced-4 loss-of-function alleles, indicating that both caspase protein CED-3 and Apaf-1 protein CED-4 were required for TBT-induced apoptosis. TBT-induced apoptosis was blocked in the Bcl-2 gain-of-function strain ced-9(n1950), whereas TBT induced a minor increase in the BH3-only protein EGL-1 mutated strain egl-1(n1084n3082). Checkpoint proteins HUS-1 and CLK-2 exerted proapoptotic effects, and the null mutation of cep-1, the homologue of tumor suppressor gene p53, significantly inhibited TBT-induced apoptosis. Apoptosis in the loss-of-function strains of ERK, JNK and p38 MAPK signaling pathways were completely or mildly suppressed under TBT stress. These results were supported by the results of mRNA expression levels of corresponding genes. The present study indicated that TBT-induced apoptosis required the core apoptotic machinery, and that DDR genes and MAPK pathways played essential roles in signaling the processes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. The Investigation of Tramadol Dependence with No History of Substance Abuse: A Cross-Sectional Survey of Spontaneously Reported Cases in Guangzhou City, China

    Directory of Open Access Journals (Sweden)

    Haoran Zhang

    2013-01-01

    Full Text Available The study was to survey and assess the drug dependence and abuse potential of tramadol with no history of substance abuse. Subjects of tramadol dependence with no prior history of substance abuse were surveyed by interview. Physical dependence of tramadol was assessed using 10 items opiate withdrawal scale (OWS, and psychological dependence was assessed by Addiction Research Center Inventory—Chinese Version (ARCI-CV. Twenty-three male subjects (the median age was 23.4±4.1 years referred to the addiction unit in Medical Hospital of Guangzhou with tramadol abuse problems were included in this cross-sectional study. The control group included 87 heroin addicts, 60 methamphetamine (MA abusers, and 50 healthy men. The scores of OWS of tramadol were 0.83–2.30; the mean scores of identifying euphoric effects–MBG, sedative effects–PCAG, and psychotomimetic effects–LSD of ARCI were 8.96±3.08, 6.52±3.25, and 6.65±2.50, respectively, F = 4.927, P0.05 but were higher than those in healthy men (P<0.05. Tramadol with no history of substance abuse has a clear risk of producing high abuse potential under the long-term infrequent abuse and the high doses.

  2. The random co-polymer glatiramer acetate rapidly kills primary human leukocytes through sialic-acid-dependent cell membrane damage

    DEFF Research Database (Denmark)

    Christiansen, Stig Hill; Zhang, Xianwei; Juul-Madsen, Kristian

    2017-01-01

    in innate immunity. It shares the positive charge and amphipathic character of GA, and, as shown here, also the ability to kill human leukocyte. The cytotoxicity of both compounds depends on sialic acid in the cell membrane. The killing was associated with the generation of CD45 + debris, derived from cell...... membrane deformation. Nanoparticle tracking analysis confirmed the formation of such debris, even at low GA concentrations. Electric cell-substrate impedance sensing measurements also recorded stable alterations in T lymphocytes following such treatment. LL-37 forms oligomers through weak hydrophobic...

  3. Rab9-dependent autophagy is required for the IGF-IIR triggering mitophagy to eliminate damaged mitochondria.

    Science.gov (United States)

    Huang, Chih-Yang; Kuo, Wei-Wen; Ho, Tsung-Jung; Chiang, Shu-Fen; Pai, Pei-Ying; Lin, Jing-Ying; Lin, Ding-Yu; Kuo, Chia-Hua; Huang, Chih-Yang

    2018-03-25

    Mitochondria dysfunction is the major characteristic of mitophagy, which is essential in mitochondrial quality control. However, excessive mitophagy contributes to cell death in a number of diseases, including ischemic stroke and hepatotoxicity. Insulin-like growth factor II (IGF-II) and its receptor (IGF-IIR) play vital roles in the development of heart failure during hypertension. We found that IGF-II triggers IGF-IIR receptor activation, causing mitochondria dysfunction, resulting in mitophagy, and cardiomyocyte cell death. These results indicated that IGF-IIR activation triggers mitochondria fragmentation, leading to autophagosome formation, and loss of mitochondria content. These results are associated with Parkin-dependent mitophagy. Additionally, autophagic proteins Atg5, and Atg7 deficiency did not suppress IGF-IIR-induced mitophagy. However, Rab9 knockdown reduced mitophagy and maintained mitochondrial function. These constitutive mitophagies through IGF-IIR activation trigger mitochondria loss and mitochondrial ROS accumulation for cardiomyocyte viability decrease. Together, our results indicate that IGF-IIR predominantly induces mitophagy through the Rab9-dependent alternative autophagy. © 2018 Wiley Periodicals, Inc.

  4. Molecular profiling of fungal communities in moisture damaged buildings before and after remediation - a comparison of culture-dependent and culture-independent methods

    Directory of Open Access Journals (Sweden)

    Auvinen Petri

    2011-10-01

    Full Text Available Abstract Background Indoor microbial contamination due to excess moisture is an important contributor to human illness in both residential and occupational settings. However, the census of microorganisms in the indoor environment is limited by the use of selective, culture-based detection techniques. By using clone library sequencing of full-length internal transcribed spacer region combined with quantitative polymerase chain reaction (qPCR for 69 fungal species or assay groups and cultivation, we have been able to generate a more comprehensive description of the total indoor mycoflora. Using this suite of methods, we assessed the impact of moisture damage on the fungal community composition of settled dust and building material samples (n = 8 and 16, correspondingly. Water-damaged buildings (n = 2 were examined pre- and post- remediation, and compared with undamaged reference buildings (n = 2. Results Culture-dependent and independent methods were consistent in the dominant fungal taxa in dust, but sequencing revealed a five to ten times higher diversity at the genus level than culture or qPCR. Previously unknown, verified fungal phylotypes were detected in dust, accounting for 12% of all diversity. Fungal diversity, especially within classes Dothideomycetes and Agaricomycetes tended to be higher in the water damaged buildings. Fungal phylotypes detected in building materials were present in dust samples, but their proportion of total fungi was similar for damaged and reference buildings. The quantitative correlation between clone library phylotype frequencies and qPCR counts was moderate (r = 0.59, p Conclusions We examined a small number of target buildings and found indications of elevated fungal diversity associated with water damage. Some of the fungi in dust were attributable to building growth, but more information on the material-associated communities is needed in order to understand the dynamics of microbial communities between

  5. On Regularly Varying and History-Dependent Convergence Rates of Solutions of a Volterra Equation with Infinite Memory

    Directory of Open Access Journals (Sweden)

    Appleby JohnAD

    2010-01-01

    Full Text Available We consider the rate of convergence to equilibrium of Volterra integrodifferential equations with infinite memory. We show that if the kernel of Volterra operator is regularly varying at infinity, and the initial history is regularly varying at minus infinity, then the rate of convergence to the equilibrium is regularly varying at infinity, and the exact pointwise rate of convergence can be determined in terms of the rate of decay of the kernel and the rate of growth of the initial history. The result is considered both for a linear Volterra integrodifferential equation as well as for the delay logistic equation from population biology.

  6. ATR- and ATM-Mediated DNA Damage Response Is Dependent on Excision Repair Assembly during G1 but Not in S Phase of Cell Cycle.

    Science.gov (United States)

    Ray, Alo; Blevins, Chessica; Wani, Gulzar; Wani, Altaf A

    2016-01-01

    Cell cycle checkpoint is mediated by ATR and ATM kinases, as a prompt early response to a variety of DNA insults, and culminates in a highly orchestrated signal transduction cascade. Previously, we defined the regulatory role of nucleotide excision repair (NER) factors, DDB2 and XPC, in checkpoint and ATR/ATM-dependent repair pathway via ATR and ATM phosphorylation and recruitment to ultraviolet radiation (UVR)-induced damage sites. Here, we have dissected the molecular mechanisms of DDB2- and XPC- mediated regulation of ATR and ATM recruitment and activation upon UVR exposures. We show that the ATR and ATM activation and accumulation to UVR-induced damage not only depends on DDB2 and XPC, but also on the NER protein XPA, suggesting that the assembly of an active NER complex is essential for ATR and ATM recruitment. ATR and ATM localization and H2AX phosphorylation at the lesion sites occur as early as ten minutes in asynchronous as well as G1 arrested cells, showing that repair and checkpoint-mediated by ATR and ATM starts early upon UV irradiation. Moreover, our results demonstrated that ATR and ATM recruitment and H2AX phosphorylation are dependent on NER proteins in G1 phase, but not in S phase. We reasoned that in G1 the UVR-induced ssDNA gaps or processed ssDNA, and the bound NER complex promote ATR and ATM recruitment. In S phase, when the UV lesions result in stalled replication forks with long single-stranded DNA, ATR and ATM recruitment to these sites is regulated by different sets of proteins. Taken together, these results provide evidence that UVR-induced ATR and ATM recruitment and activation differ in G1 and S phases due to the existence of distinct types of DNA lesions, which promote assembly of different proteins involved in the process of DNA repair and checkpoint activation.

  7. Fruit flies may face a nutrient-dependent life-history trade-off between secondary sexual trait quality, survival and developmental rate.

    Science.gov (United States)

    Gray, Lindsey J; Simpson, Stephen J; Polak, Michal

    2018-01-01

    Optimal life-history strategies are those that best allocate finite environmental resources to competing traits. We used the geometric framework for nutrition to evaluate life-history strategies followed by Drosophila melanogaster by measuring the condition-dependent performance of life-history traits, including the morphology of male secondary sexual characters, sex combs. We found that depending on their rearing environment flies faced different forms of trait trade-offs and accordingly followed different life-history strategies. High-energy, high-carbohydrate, low-protein diets supported development of the largest and most symmetrical sex combs, however, consistent with handicap models of sexual selection these foods were associated with reduced fly survival and developmental rate. Expressing the highest quality sex combs may have required secondary sexual trait quality to be traded-off with developmental rate, and our results indicated that flies unable to slow development died. As larval nutritional environments are predominantly determined by female oviposition substrate choice, we tested where mated female flies laid the most eggs. Mothers chose high-energy, high-protein foods associated with rapid larval development. Mothers avoided high-carbohydrate foods associated with maximal sex comb expression, showing they may avoid producing fewer 'sexy' sons in favour of producing offspring that develop rapidly. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. A Prospective Study of the Impact of Current Poverty, History of Poverty, and Exiting Poverty on Accumulation of Disease Damage in Systemic Lupus Erythematosus.

    Science.gov (United States)

    Yelin, Edward; Trupin, Laura; Yazdany, Jinoos

    2017-08-01

    To estimate the effect of current poverty, number of years in poverty, and exiting poverty on disease damage accumulation in systemic lupus erythematosus (SLE). For this study, 783 patients with SLE were followed up from 2003 to 2015 through annual structured interviews. Respondents were categorized in each year by whether they had a household income of ≤125% of the US federal poverty level. Linear and logistic regression analyses were used to assess the impact of poverty in 2009, number of years in poverty between 2003 and 2009, and permanent exits from poverty as of 2009 on the extent of disease damage (according to the Brief Index of Lupus Damage [BILD] score) or accumulation of a clinically meaningful increase in disease damage (defined as a minimum 2-point increase in the BILD damage score) by 2015. After adjustment for sociodemographic features, health care characteristics, and health behaviors, poverty in 2009 was associated with an increased level of accumulated disease damage in 2015 (mean difference in BILD damage score between poor and non-poor 0.62 points, 95% confidence interval [95% CI] 0.25-0.98) and increased odds of a clinically important increase in damage (odds ratio [OR] 1.67, 95% CI 0.98-2.85). Being poor in every year between 2003 and 2009 was associated with greater damage (mean change in BILD score 2.45, 95% CI 1.88-3.01) than being poor for one-half or more of those years (mean change in BILD score 1.45, 95% CI 0.97-1.93), for fewer than one-half of those years (mean change in BILD score 1.49, 95% CI 1.10-1.88), or for none of those years (mean change in BILD score 1.34, 95% CI 1.20-1.49). Those exiting poverty permanently had similar increases in disease damage (mean change in BILD score 1.30, 95% CI 0.90-1.69) as those who were never in poverty (mean change in BILD score 1.36, 95% CI 1.23-1.50) but much less damage than those who remained in poverty (mean change in BILD score 1.98, 95% CI 1.59-2.38). The effects of current poverty

  9. Cyclic creep, mechanical ratchetting and amplitude history dependence of modified 9Cr-1Mo steel and evaluation of unified constitutive models

    International Nuclear Information System (INIS)

    Tanaka, Eiichi; Yamada, Hiroshi

    1993-01-01

    The purpose of the present paper is to elucidate inelastic behavior of modified 9Cr-1Mo steel as a candidate material for the next-generation fast breeder reactor and to provide the information for the formulation of a unified constitutive model. For this purpose, cyclic creep, mechanical ratchetting and amplitude history dependence of cyclic hardening were first examined at 550degC. As a result, systematic cyclic creep and mechanical ratchetting behavior were observed under various loading conditions, and little amplitude history dependence was found. Then these results were simulated by three unified constitutive models, i.e. the Chaboche, Bodner-Partom and modified Chaboche models. The simulated results show that these models cannot describe the cyclic creep and mechanical ratchetting behavior with high accuracy, but succeed in describing the inelastic behavior of amplitude variation experiments. (author)

  10. Nanomechanical Characterization of Temperature-Dependent Mechanical Properties of Ion-Irradiated Zirconium with Consideration of Microstructure and Surface Damage

    Science.gov (United States)

    Marsh, Jonathan; Zhang, Yang; Verma, Devendra; Biswas, Sudipta; Haque, Aman; Tomar, Vikas

    2015-12-01

    Zirconium alloys for nuclear applications with different microstructures were produced by manufacturing processes such as chipping, rolling and annealing. The two Zr samples, rolled and rolled-annealed were subjected to different levels of irradiation, 1 keV and 100 eV, to study the effect of irradiation dosages. The effect of microstructure and irradiation on the mechanical properties (reduced modulus, hardness, indentation yield strength) was analyzed with nanoindentation experiments, which were carried out in the temperature range of 25°C to 450°C to investigate temperature dependence. An indentation size effect analysis was performed and the mechanical properties were also corrected for the oxidation effects at high temperatures. The irradiation-induced hardness was observed, with rolled samples exhibiting higher increase compared to rolled and annealed samples. The relevant material parameters of the Anand viscoplastic model were determined for Zr samples containing different level of irradiation to account for viscoplasticity at high temperatures. The effect of the microstructure and irradiation on the stress-strain curve along with the influence of temperature on the mechanisms of irradiation creep such as formation of vacancies and interstitials is presented. The yield strength of irradiated samples was found to be higher than the unirradiated samples which also showed a decreasing trend with the temperature.

  11. Transcriptional Response of Human Neurospheres to Helper-Dependent CAV-2 Vectors Involves the Modulation of DNA Damage Response, Microtubule and Centromere Gene Groups.

    Directory of Open Access Journals (Sweden)

    Stefania Piersanti

    Full Text Available Brain gene transfer using viral vectors will likely become a therapeutic option for several disorders. Helper-dependent (HD canine adenovirus type 2 vectors (CAV-2 are well suited for this goal. These vectors are poorly immunogenic, efficiently transduce neurons, are retrogradely transported to afferent structures in the brain and lead to long-term transgene expression. CAV-2 vectors are being exploited to unravel behavior, cognition, neural networks, axonal transport and therapy for orphan diseases. With the goal of better understanding and characterizing HD-CAV-2 for brain therapy, we analyzed the transcriptomic modulation induced by HD-CAV-2 in human differentiated neurospheres derived from midbrain progenitors. This 3D model system mimics several aspects of the dynamic nature of human brain. We found that differentiated neurospheres are readily transduced by HD-CAV-2 and that transduction generates two main transcriptional responses: a DNA damage response and alteration of centromeric and microtubule probes. Future investigations on the biochemistry of processes highlighted by probe modulations will help defining the implication of HD-CAV-2 and CAR receptor binding in enchaining these functional pathways. We suggest here that the modulation of DNA damage genes is related to viral DNA, while the alteration of centromeric and microtubule probes is possibly enchained by the interaction of the HD-CAV-2 fibre with CAR.

  12. Impacts of Repeated Glyphosate Use on Wheat-Associated Bacteria Are Small and Depend on Glyphosate Use History.

    Science.gov (United States)

    Schlatter, Daniel C; Yin, Chuntao; Hulbert, Scot; Burke, Ian; Paulitz, Timothy

    2017-11-15

    Glyphosate is the most widely used herbicide worldwide and a critical tool for weed control in no-till cropping systems. However, there are concerns about the nontarget impacts of long-term glyphosate use on soil microbial communities. We investigated the impacts of repeated glyphosate treatments on bacterial communities in the soil and rhizosphere of wheat in soils with and without long-term history of glyphosate use. We cycled wheat in the greenhouse using soils from 4 paired fields under no-till (20+-year history of glyphosate) or no history of use. At each cycle, we terminated plants with glyphosate (2× the field rate) or by removing the crowns, and soil and rhizosphere bacterial communities were characterized. Location, cropping history, year, and proximity to the roots had much stronger effects on bacterial communities than did glyphosate, which only explained 2 to 5% of the variation. Less than 1% of all taxa were impacted by glyphosate, more in soils with a long history of use, and more increased than decreased in relative abundance. Glyphosate had minimal impacts on soil and rhizosphere bacteria of wheat, although dying roots after glyphosate application may provide a "greenbridge" favoring some copiotrophic taxa. IMPORTANCE Glyphosate (Roundup) is the most widely used herbicide in the world and the foundation of Roundup Ready soybeans, corn, and the no-till cropping system. However, there have been recent concerns about nontarget impacts of glyphosate on soil microbes. Using next-generation sequencing methods and glyphosate treatments of wheat plants, we described the bacterial communities in the soil and rhizosphere of wheat grown in Pacific Northwest soils across multiple years, different locations, and soils with different histories of glyphosate use. The effects of glyphosate were subtle and much less than those of drivers such as location and cropping systems. Only a small percentage of the bacterial groups were influenced by glyphosate, and most of

  13. Hyperoside attenuates hydrogen peroxide-induced L02 cell damage via MAPK-dependent Keap{sub 1}-Nrf{sub 2}-ARE signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Xing, Hai-Yan; Liu, Yao; Chen, Jian-Hong; Sun, Feng-Jun; Shi, Hui-Qing [Department of Pharmacy, Southwest Hospital, Third Military Medical University, Chongqing 400038 (China); Xia, Pei-Yuan, E-mail: py_xia@yahoo.com.cn [Department of Pharmacy, Southwest Hospital, Third Military Medical University, Chongqing 400038 (China)

    2011-07-15

    Highlights: {yields} Hyperoside attenuated H{sub 2}O{sub 2}-induced L02 cell damage. {yields} Hyperoside up-regulated HO-1 expression at both mRNA and protein levels. {yields} Hyperoside activated both Nrf{sub 2} nuclear translocation and gene expression. {yields} Hyperoside may inhibit Keap{sub 1} mRNA translation or protein degradation. {yields} Phosphorylation of ERK and p38 is involved in hyperoside-mediated Nrf{sub 2} activation. -- Abstract: The flavonoid hyperoside has been reported to elicit cytoprotection against oxidative stress partly by increasing the activity of antioxidant enzymes, such as glutathione peroxidase, superoxide dismutase and catalase. However, the cellular and molecular mechanisms underlying this effect remain unclear. Here, hepatic L02 cells exposed to H{sub 2}O{sub 2} (100 {mu}M) were used to demonstrate that hyperoside protected cells by significantly inhibiting overproduction of intracellular ROS, depletion of the mitochondrial membrane potential and leakage of lactate dehydrogenase. Hyperoside further enhanced the cellular antioxidant defense system through increasing the activity of heme oxygenase-1 (HO-1), and by up-regulating HO-1 expression. Meanwhile, real time PCR, western blot and immunofluorescence studies revealed that hyperoside stimulated nuclear translocation of the Nrf{sub 2} transcription factor in a dose-dependent manner, and this effect was significantly suppressed by pharmacological inhibition of the mitogen-activated protein kinases (MAPK) p38 and ERK. Collectively, our data provide the first description of the mechanism underlying hyperoside's ability to attenuate H{sub 2}O{sub 2}-induced cell damage, namely this compound interacts with the MAPK-dependent Keap{sub 1}-Nrf{sub 2}-ARE signaling pathway to up-regulate HO-1 expression and enhance intracellular antioxidant activity.

  14. Cell type-dependent induction of DNA damage by 1800 MHz radiofrequency electromagnetic fields does not result in significant cellular dysfunctions.

    Directory of Open Access Journals (Sweden)

    Shanshan Xu

    Full Text Available BACKGROUND: Although IARC clarifies radiofrequency electromagnetic fields (RF-EMF as possible human carcinogen, the debate on its health impact continues due to the inconsistent results. Genotoxic effect has been considered as a golden standard to determine if an environmental factor is a carcinogen, but the currently available data for RF-EMF remain controversial. As an environmental stimulus, the effect of RF-EMF on cellular DNA may be subtle. Therefore, more sensitive method and systematic research strategy are warranted to evaluate its genotoxicity. OBJECTIVES: To determine whether RF-EMF does induce DNA damage and if the effect is cell-type dependent by adopting a more sensitive method γH2AX foci formation; and to investigate the biological consequences if RF-EMF does increase γH2AX foci formation. METHODS: Six different types of cells were intermittently exposed to GSM 1800 MHz RF-EMF at a specific absorption rate of 3.0 W/kg for 1 h or 24 h, then subjected to immunostaining with anti-γH2AX antibody. The biological consequences in γH2AX-elevated cell type were further explored with comet and TUNEL assays, flow cytometry, and cell growth assay. RESULTS: Exposure to RF-EMF for 24 h significantly induced γH2AX foci formation in Chinese hamster lung cells and Human skin fibroblasts (HSFs, but not the other cells. However, RF-EMF-elevated γH2AX foci formation in HSF cells did not result in detectable DNA fragmentation, sustainable cell cycle arrest, cell proliferation or viability change. RF-EMF exposure slightly but not significantly increased the cellular ROS level. CONCLUSIONS: RF-EMF induces DNA damage in a cell type-dependent manner, but the elevated γH2AX foci formation in HSF cells does not result in significant cellular dysfunctions.

  15. Field and sample history dependence of the compensation temperature in Sm0.97Gd0.03Al2

    International Nuclear Information System (INIS)

    Vaidya, U.V.; Rakhecha, V.C.; Sumithra, S.; Ramakrishnan, S.; Grover, A.K.

    2007-01-01

    We present magnetization data on three polycrystalline specimens of Sm 0.97 Gd 0.03 Al 2 : (1) as-cast (grainy texture), (2) powder, and (3) re-melted fast-quenched (plate). The data are presented for nominally zero- (ZFC) and high-field-cooling (HFC) histories. A zero cross-over in magnetization curve at some temperature T=T 0 was seen in ZFC data on grainy and powder samples, but not in the plate sample. At fields surpassing magnetocrystalline anisotropy, a 4f magnetic moment flip was still evidenced by HFC data in all samples at a compensation temperature T comp , which must necessarily be treated as distinct from T 0 (T 0 may not even exist). Proper understanding of T comp should take account of thermomagnetic history effects

  16. DNA double strand break repair is enhanced by P53 following induction by DNA damage and is dependent on the C-terminal domain of P53

    International Nuclear Information System (INIS)

    Wei Tang; Powell, Simon N.

    1996-01-01

    Purpose: The tumor suppressor gene p53 can mediate cell cycle arrest or apoptosis in response to DNA damage. Accumulating evidence suggests that it may also directly or indirectly influence the DNA repair machinery. In the present study, we investigated whether p53, induced by DNA damage, could enhance the rejoining of double-strand DNA breaks. Materials and Methods: DNA double-strand breaks (dsb) were made by restriction enzyme digestion of a plasmid, between a promoter and a 'reporter' gene: luciferase (LUC) or chloramphenicol acetyl-transferase (CAT). Linear or circular plasmid DNA (LUC or CAT) was co-transfected with circular β-Gal plasmid (to normalize for uptake) into mouse embryonic fibroblasts genetically matched to be (+/+) or (-/-) for p53. Their ability to rejoin linearized plasmid was measured by the luciferase or CAT activity detected in rescued plasmids. The activity detected in cells transfected with linear plasmid was scored relative to the activity detected in cells transfected with circular plasmid. Results: Ionizing radiation (IR, 2 Gy) enhanced the dsb repair activity in wild type p53 cells; however, p53 null cells lose this effect, indicating that the enhancement of dsb repair was p53-dependent. REF cells with dominant-negative mutant p53 showed a similar induction compared with the parental REF cells with wild-type p53. This ala-143 mutant p53 prevents cell cycle arrest and transactivation of p21 WAF1/cip1) following IR, indicating that the p53-dependent enhancement of DNA repair is distinct from transactivation. Immortalized murine embryonic fibroblasts, 10(1)VasK1 cells, which express p53 cDNA encoding a temperature-sensitive mutant in the DNA sequence specific binding domain (ala135 to val135) with an alternatively spliced C-terminal domain (ASp53: amino-acids 360-381) and, 10(1)Val5 cells, which express the normal spliced p53 (NSp53) with the same temperature-sensitive mutant were compared. It was found that 10(1)VasK1 cells showed no DNA

  17. Probability of growth of small damage sites on the exit surface of fused silica optics.

    Science.gov (United States)

    Negres, Raluca A; Abdulla, Ghaleb M; Cross, David A; Liao, Zhi M; Carr, Christopher W

    2012-06-04

    Growth of laser damage on fused silica optical components depends on several key parameters including laser fluence, wavelength, pulse duration, and site size. Here we investigate the growth behavior of small damage sites on the exit surface of SiO₂ optics under exposure to tightly controlled laser pulses. Results demonstrate that the onset of damage growth is not governed by a threshold, but is probabilistic in nature and depends both on the current size of a damage site and the laser fluence to which it is exposed. We also develop models for use in growth prediction. In addition, we show that laser exposure history also influences the behavior of individual sites.

  18. Measures of Dependence for α-Stable Distributed Processes and Its Application to Diagnostics of Local Damage in Presence of Impulsive Noise

    Directory of Open Access Journals (Sweden)

    Grzegorz Żak

    2017-01-01

    Full Text Available Local damage detection in rotating machinery is simply searching for cyclic impulsive signal in noisy observation. Such raw signal is mixture of various components with specific properties (deterministic, random, cyclic, impulsive, etc.. The problem appears when the investigated process is based on one of the heavy-tailed distributions. In this case the classical measure can not be considered. Therefore, alternative measures of dependence adequate for such processes should be considered. In this paper we examine the structure of dependence of alpha-stable based systems expressed by means of two measures, namely, codifference and covariation. The reason for using alpha-stable distribution is simple and intuitive: signal of interest is impulsive so its distribution is heavy-tailed. The main goal is to introduce a new technique for estimation of covariation. Due to the complex nature of such vibration signals applying novel methods instead of classical ones is recommended. Classical algorithms usually are based on the assumption that theoretical second moment is finite, which is not true in case of the data acquired on the faulty components. Main advantage of our proposed algorithm is independence from second moment assumption.

  19. Single and double metallothionein knockout in the nematode C. elegans reveals cadmium dependent and independent toxic effects on life history traits

    International Nuclear Information System (INIS)

    Hughes, Sam; Stuerzenbaum, Stephen R.

    2007-01-01

    The genome of the nematode Caenorhabditis elegans contains two metallothionein genes, both involved in metal homeostasis and/or detoxification. Single metallothionein knockout mutants have been created and now, for the first time, a double mutant has been isolated. Life history studies in the presence or absence of cadmium showed that all metallothionein mutants are viable. Although cadmium did not influence longevity, a dose dependent reduction in total brood size and volumetric growth was observed in wild type animals, which was magnified in single knockouts and further exacerbated in the double knockout. However, the metallothionein deletion caused two effects that are independent of cadmium exposure, namely all knockout strains displayed a reduced total brood size and the deletion of both metallothionein loci caused a significant reduction in volumetric growth. In summary, metallothionein is undoubtedly an important player in cadmium detoxification, but evidently also an important factor in cadmium independent pathways. - Metallothionein is a modifier of life-history parameters

  20. Single and double metallothionein knockout in the nematode C. elegans reveals cadmium dependent and independent toxic effects on life history traits

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Sam [School of Biosciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3TL (United Kingdom); School of Biomedical and Health Sciences, Pharmaceutical Sciences Research Division, King' s College London, 150 Stamford Street, London SE1 9NH (United Kingdom); Stuerzenbaum, Stephen R. [School of Biosciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3TL (United Kingdom) and School of Biomedical and Health Sciences, Pharmaceutical Sciences Research Division, King' s College London, 150 Stamford Street, London SE1 9NH (United Kingdom)]. E-mail: stephen.sturzenbaum@kcl.ac.uk

    2007-01-15

    The genome of the nematode Caenorhabditis elegans contains two metallothionein genes, both involved in metal homeostasis and/or detoxification. Single metallothionein knockout mutants have been created and now, for the first time, a double mutant has been isolated. Life history studies in the presence or absence of cadmium showed that all metallothionein mutants are viable. Although cadmium did not influence longevity, a dose dependent reduction in total brood size and volumetric growth was observed in wild type animals, which was magnified in single knockouts and further exacerbated in the double knockout. However, the metallothionein deletion caused two effects that are independent of cadmium exposure, namely all knockout strains displayed a reduced total brood size and the deletion of both metallothionein loci caused a significant reduction in volumetric growth. In summary, metallothionein is undoubtedly an important player in cadmium detoxification, but evidently also an important factor in cadmium independent pathways. - Metallothionein is a modifier of life-history parameters.

  1. History, distribution, damage, and life cycle of a pine shoot gali sawfly, Xyela gallicaulis (Hymenoptera: Xyelidae). J. Entomol. Sci. 44(3):276-283

    Science.gov (United States)

    Harry O. Yates; David R. Smith

    2009-01-01

    Larvae of Xyela gallicaulis Smith cause shoot stem galls in young pines. Loblolly pine, Pinus taeda L., is the most seriously damaged, but galls have been observed on slash pine, P. elliottii var. elliottii Engelm., and shortleaf pine, P. echinata Mill. Studies in Virginia and Georgia confirm a 2-year life cycle. Larval development takes...

  2. Proliferating Cell Nuclear Antigen-dependent Rapid Recruitment of Cdt1 and CRL4Cdt2 at DNA-damaged Sites after UV Irradiation in HeLa Cells*

    Science.gov (United States)

    Ishii, Takashi; Shiomi, Yasushi; Takami, Toshihiro; Murakami, Yusuke; Ohnishi, Naho; Nishitani, Hideo

    2010-01-01

    The licensing factor Cdt1 is degraded by CRL4Cdt2 ubiquitin ligase dependent on proliferating cell nuclear antigen (PCNA) during S phase and when DNA damage is induced in G1 phase. Association of both Cdt2 and PCNA with chromatin was observed in S phase and after UV irradiation. Here we used a micropore UV irradiation assay to examine Cdt2 accumulation at cyclobutane pyrimidine dimer-containing DNA-damaged sites in the process of Cdt1 degradation in HeLa cells. Cdt2, present in the nucleus throughout the cell cycle, accumulated rapidly at damaged DNA sites during G1 phase. The recruitment of Cdt2 is dependent on prior PCNA chromatin binding because Cdt2 association was prevented when PCNA was silenced. Cdt1 was also recruited to damaged sites soon after UV irradiation through its PIP-box. As Cdt1 was degraded, the Cdt2 signal at damaged sites was reduced, but PCNA, cyclobutane pyrimidine dimer, and XPA (xeroderma pigmentosum, complementation group A) signals remained at the same levels. These findings suggest that Cdt1 degradation following UV irradiation occurs rapidly at damaged sites due to PCNA chromatin loading and the recruitment of Cdt1 and CRL4Cdt2, before DNA damage repair is completed. PMID:20929861

  3. Effects of place identity, place dependence, and experience-use history on perceptions of recreation impacts in a natural setting.

    Science.gov (United States)

    White, Dave D; Virden, Randy J; van Riper, Carena J

    2008-10-01

    It is generally accepted that recreation use in natural environments results in some degree of negative social and environmental impact. Environmental managers are tasked with mitigating the impact while providing beneficial recreation opportunities. Research on the factors that influence visitors' perceptions of environmental and social conditions is necessary to inform sound environmental management of protected natural areas. This study examines the effect of prior experience with the setting and two dimensions of place attachment (i.e., place identity and place dependence) on visitors' perceptions of three types of recreation impacts (i.e., depreciative behavior, environmental impacts, and recreation conflict). Principal components analysis, confirmatory factor analysis, and structural equation modeling were used to test the study hypotheses using data collected from 351 visitors through on-site questionnaires (response rate of 93 percent). The results show that prior experience exhibited a moderate and significant direct positive effect on place identity, place dependence, and visitors' perceptions of recreation impacts. Contrary to study hypotheses and prior research, neither place dependence nor place identity exhibited a significant effect on the dependent variables. The results show that prior experience causes visitors to be more sensitive to depreciative behaviors, environmental impacts, and recreation conflict. These findings raise concerns over potential visitor displacement and deterioration of site conditions. Implications for resource managers are discussed, which include education, modifying visitor use patterns, and site design strategies.

  4. Effects of Place Identity, Place Dependence, and Experience-Use History on Perceptions of Recreation Impacts in a Natural Setting

    Science.gov (United States)

    White, Dave D.; Virden, Randy J.; van Riper, Carena J.

    2008-10-01

    It is generally accepted that recreation use in natural environments results in some degree of negative social and environmental impact. Environmental managers are tasked with mitigating the impact while providing beneficial recreation opportunities. Research on the factors that influence visitors’ perceptions of environmental and social conditions is necessary to inform sound environmental management of protected natural areas. This study examines the effect of prior experience with the setting and two dimensions of place attachment (i.e., place identity and place dependence) on visitors’ perceptions of three types of recreation impacts (i.e., depreciative behavior, environmental impacts, and recreation conflict). Principal components analysis, confirmatory factor analysis, and structural equation modeling were used to test the study hypotheses using data collected from 351 visitors through on-site questionnaires (response rate of 93 percent). The results show that prior experience exhibited a moderate and significant direct positive effect on place identity, place dependence, and visitors’ perceptions of recreation impacts. Contrary to study hypotheses and prior research, neither place dependence nor place identity exhibited a significant effect on the dependent variables. The results show that prior experience causes visitors to be more sensitive to depreciative behaviors, environmental impacts, and recreation conflict. These findings raise concerns over potential visitor displacement and deterioration of site conditions. Implications for resource managers are discussed, which include education, modifying visitor use patterns, and site design strategies.

  5. Life-history dependent relationships between body condition and immunity, between immunity indices in male Eurasian tree sparrows.

    Science.gov (United States)

    Zhao, Yuliang; Li, Mo; Sun, Yanfeng; Wu, Wei; Kou, Guanqun; Guo, Lingling; Xing, Danning; Wu, Yuefeng; Li, Dongming; Zhao, Baohua

    2017-08-01

    In free-living animals, recent evidence indicates that innate, and acquired, immunity varies with annual variation in the demand for, and availability of, food resources. However, little is known about how animals adjust the relationships between immunity and body condition, and between innate and acquired immunity to optimize survival over winter and reproductive success during the breeding stage. Here, we measured indices of body condition (size-corrected mass [SCM], and hematocrit [Hct]), constitutive innate immunity (plasma total complement hemolysis activity [CH 50 ]) and acquired immunity (plasma immunoglobulin A [IgA]), plus heterophil/lymphocyte (H/L) ratios, in male Eurasian tree sparrows (Passer montanus) during the wintering and the breeding stages. We found that birds during the wintering stage had higher IgA levels than those from the breeding stage. Two indices of body condition were both negatively correlated with plasma CH 50 activities, and positively with IgA levels in wintering birds, but this was not the case in the breeding birds. However, there was no correlation between CH 50 activities and IgA levels in both stages. These results suggest that the relationships between body condition and immunity can vary across life-history stage, and there are no correlations between innate and acquired immunity independent of life-history stage, in male Eurasian tree sparrows. Therefore, body condition indices predict immunological state, especially during the non-breeding stage, which can be useful indicators of individual immunocompetences for understanding the variations in innate and acquired immunity in free-living animals. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Recent History of Effector Use Modulates Practice-Dependent Changes in Corticospinal Excitability but Not Motor Learning.

    Science.gov (United States)

    Hussain, Sara J; Darling, Warren G; Cole, Kelly J

    2016-01-01

    The theory of homeostatic metaplasticity has significant implications for human motor cortical plasticity and motor learning. Previous work has shown that the extent of recent effector use before exogenously-induced plasticity can affect the direction, magnitude and variability of aftereffects. However, the impact of recent effector use on motor learning and practice-dependent plasticity is not known. We hypothesized that reducing effector use for 8 hours via hand/wrist immobilization would facilitate practice-dependent changes in corticospinal excitability and TMS-evoked thumb movement kinematics, while also promoting 24-hour retention of a ballistic motor skill. Subjects participated in a crossover study involving two conditions. During the immobilization condition, subjects wore a splint that restricted motion of the left hand and thumb for 8 hours. While wearing the splint, subjects were instructed to avoid using their left hand as much as possible. During the control condition, subjects did not wear a splint at any time nor were they instructed to avoid hand use. After either an 8 hour period of immobilization or normal hand use, we collected MEP and TMS-evoked thumb movement recruitment curves, and subjects practiced a ballistic motor skill involving rapid thumb extension. After motor practice, MEP and TMS-evoked thumb movement recruitment curves were re-tested. Retention of the motor skill was tested 30 minutes and 24 hours after motor practice. Reduced effector use did not impact pre-practice corticospinal excitability but did facilitate practice-dependent changes in corticospinal excitability, and this enhancement was specific to the trained muscle. In contrast, reducing effector use did not affect practice-dependent changes in TMS-evoked thumb movements nor did it promote acquisition or retention of the skill. Finally, we detected some associations between pre-practice excitability levels, plasticity effects and learning effects, but these did not reach

  7. The susceptibility of soil enzymes to inhibition by leaf litter tannins is dependent on the tannin chemistry, enzyme class and vegetation history.

    Science.gov (United States)

    Triebwasser, Daniella J; Tharayil, Nishanth; Preston, Caroline M; Gerard, Patrick D

    2012-12-01

    By inhibiting soil enzymes, tannins play an important role in soil carbon (C) and nitrogen (N) mineralization. The role of tannin chemistry in this inhibitory process, in conjunction with enzyme classes and isoforms, is less well understood. Here, we compared the inhibition efficiencies of mixed tannins (MTs, mostly limited to angiosperms) and condensed tannins (CTs, produced mostly by gymnosperms) against the potential activity of β-glucosidase (BG), N-acetyl-glucosaminidase (NAG), and peroxidase in two soils that differed in their vegetation histories. Compared with CTs, MTs exhibited 50% more inhibition of almond (Prunus dulcis) BG activity and greater inhibition of the potential NAG activity in the gymnosperm-acclimatized soils. CTs exhibited lower BG inhibition in the angiosperm-acclimated soils, whereas both types of tannins exhibited higher peroxidase inhibition in the angiosperm soils than in gymnosperm soils. At all of the tested tannin concentrations, irrespective of the tannin type and site history, the potential peroxidase activity was inhibited two-fold more than the hydrolase activity and was positively associated with the redox-buffering efficiency of tannins. Our finding that the inhibitory activities and mechanisms of MTs and CTs are dependent on the vegetative history and enzyme class is novel and furthers our understanding of the role of tannins and soil isoenzymes in decomposition. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  8. Combinatorial DNA Damage Pairing Model Based on X-Ray-Induced Foci Predicts the Dose and LET Dependence of Cell Death in Human Breast Cells

    Energy Technology Data Exchange (ETDEWEB)

    Vadhavkar, Nikhil [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Pham, Christopher [University of Texas, Houston, TX (United States). MD Anderson Cancer Center; Georgescu, Walter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Deschamps, Thomas [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Heuskin, Anne-Catherine [Univ. of Namur (Belgium). Namur Research inst. for Life Sciences (NARILIS), Research Center for the Physics of Matter and Radiation (PMR); Tang, Jonathan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Costes, Sylvain V. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.

    2014-09-01

    In contrast to the classic view of static DNA double-strand breaks (DSBs) being repaired at the site of damage, we hypothesize that DSBs move and merge with each other over large distances (m). As X-ray dose increases, the probability of having DSB clusters increases as does the probability of misrepair and cell death. Experimental work characterizing the X-ray dose dependence of radiation-induced foci (RIF) in nonmalignant human mammary epithelial cells (MCF10A) is used here to validate a DSB clustering model. We then use the principles of the local effect model (LEM) to predict the yield of DSBs at the submicron level. Two mechanisms for DSB clustering, namely random coalescence of DSBs versus active movement of DSBs into repair domains are compared and tested. Simulations that best predicted both RIF dose dependence and cell survival after X-ray irradiation favored the repair domain hypothesis, suggesting the nucleus is divided into an array of regularly spaced repair domains of ~;;1.55 m sides. Applying the same approach to high-linear energy transfer (LET) ion tracks, we are able to predict experimental RIF/m along tracks with an overall relative error of 12percent, for LET ranging between 30 350 keV/m and for three different ions. Finally, cell death was predicted by assuming an exponential dependence on the total number of DSBs and of all possible combinations of paired DSBs within each simulated RIF. Relative biological effectiveness (RBE) predictions for cell survival of MCF10A exposed to high-LET showed an LET dependence that matches previous experimental results for similar cell types. Overall, this work suggests that microdosimetric properties of ion tracks at the submicron level are sufficient to explain both RIF data and survival curves for any LET, similarly to the LEM assumption. Conversely, high-LET death mechanism does not have to infer linear-quadratic dose formalism as done in the LEM. In addition, the size of repair domains derived in our model

  9. Satellite alignment. I. Distribution of substructures and their dependence on assembly history from n-body simulations

    International Nuclear Information System (INIS)

    Wang, Yang Ocean; Lin, W. P.; Yu, Yu; Kang, X.; Dutton, Aaron; Macciò, Andrea V.

    2014-01-01

    Observations have shown that the spatial distribution of satellite galaxies is not random, but aligned with the major axes of central galaxies. This alignment is dependent on galaxy properties, such that red satellites are more strongly aligned than blue satellites. Theoretical work conducted to interpret this phenomenon has found that it is due to the non-spherical nature of dark matter halos. However, most studies overpredict the alignment signal under the assumption that the central galaxy shape follows the shape of the host halo. It is also not clear whether the color dependence of alignment is due to an assembly bias or an evolution effect. In this paper we study these problems using a cosmological N-body simulation. Subhalos are used to trace the positions of satellite galaxies. It is found that the shapes of dark matter halos are mis-aligned at different radii. If the central galaxy shares the same shape as the inner host halo, then the alignment effect is weaker and agrees with observational data. However, it predicts almost no dependence of alignment on the color of satellite galaxies, though the late accreted subhalos show stronger alignment with the outer layer of the host halo than their early accreted counterparts. We find that this is due to the limitation of pure N-body simulations where satellite galaxies without associated subhalos ('orphan galaxies') are not resolved. These orphan (mostly red) satellites often reside in the inner region of host halos and should follow the shape of the host halo in the inner region.

  10. Numerical analysis of breakdown dynamics dependence on pulse width in laser-induced damage in fused silica: Role of optical system

    Science.gov (United States)

    Hamam, Kholoud A.; Gamal, Yosr E. E.-D.

    2018-06-01

    We report a numerical investigation of the breakdown and damage in fused silica caused by ultra-short laser pulses. The study based on a modified model (Gaabour et al., 2012) that solves the rate equation numerically for the electron density evolution during the laser pulse, under the combined effect of both multiphoton and electron impact ionization processes. Besides, electron loss processes due to diffusion out of the focal volume and recombination are also considered in this analysis. The model is applied to investigate the threshold intensity dependence on laser pulse width in the experimental measurements that are given by Liu et al. (2005). In this experiment, a Ti-sapphire laser source operating at 800 nm with pulse duration varies between 240 fs and 2.5 ps is used to irradiate a bulk of fused silica with dimensions 10 × 5 × 3 mm. The laser beam was focused into the bulk using two optical systems with effective numerical apertures (NA) 0.126 and 0.255 to give beam spot radius at the focus of the order 2.0 μm and 0.95 μm respectively. Reasonable agreement between the calculated thresholds and the measured ones is attained. Moreover, a study is performed to examine the respective role of the physical processes of the breakdown of fused silica in relation to the pulse width and focusing optical system. The analysis revealed a real picture of the location and size of the generated plasma.

  11. Rat Liver Enzyme Release Depends on Blood Flow-Bearing Physical Forces Acting in Endothelium Glycocalyx rather than on Liver Damage

    Directory of Open Access Journals (Sweden)

    Julieta A. Díaz-Juárez

    2017-01-01

    Full Text Available We have found selective elevation of serum enzyme activities in rats subjected to partial hepatectomy (PH, apparently controlled by hemodynamic flow-bearing physical forces. Here, we assess the involvement of stretch-sensitive calcium channels and calcium mobilization in isolated livers, after chemical modifications of the endothelial glycocalyx and changing perfusion directionality. Inhibiting in vivo protein synthesis, we found that liver enzyme release is influenced by de novo synthesis of endothelial glycocalyx components, and released enzymes are confined into a liver “pool.” Moreover, liver enzyme release depended on extracellular calcium entry possibly mediated by stretch-sensitive calcium channels, and this endothelial-mediated mechanotransduction in liver enzyme release was also evidenced by modifying the glycocalyx carbohydrate components, directionality of perfusing flow rate, and the participation of nitric oxide (NO and malondialdehyde (MDA, leading to modifications in the intracellular distribution of these enzymes mainly as nuclear enrichment of “mitochondrial” enzymes. In conclusion, the flow-induced shear stress may provide fine-tuned control of released hepatic enzymes through mediation by the endothelium glycocalyx, which provides evidence of a biological role of the enzyme release rather to be merely a biomarker for evaluating hepatotoxicity and liver damage, actually positively influencing progression of liver regeneration in mammals.

  12. Dependence of diameters and oxygen saturation of retinal vessels on visual field damage and age in primary open-angle glaucoma.

    Science.gov (United States)

    Ramm, Lisa; Jentsch, Susanne; Peters, Sven; Sauer, Lydia; Augsten, Regine; Hammer, Martin

    2016-05-01

    To investigate the interrelationship between the oxygen supply of the retina and its regulation with the severity of primary open-angle glaucoma (POAG). Central retinal artery (CRAE) and vein (CRVE) diameters and oxygen saturation of peripapillary retinal vessels in 41 patients suffering from POAG (64.1 ± 12.9 years) and 40 healthy volunteers (63.6 ± 14.1 years) were measured using the retinal vessel analyzer. All measures were taken before and during flicker light stimulation. The mean retinal nerve fiber layer thickness (RNFLT) was determined by OCT and the visual field mean defect (MD) was identified using perimetry. In glaucoma patients, CRAE (r = -0.48 p = 0.002) and CRVE (r = -0.394 p = 0.014) at baseline were inversely related to MD, while arterial and venous oxygen saturation showed no significant dependence on the severity of the damage. However, the flicker light-induced change in arterio-venous difference in oxygen saturation was correlated with the MD (r = 0.358 p = 0.027). The diameters of arteries and veins at baseline decreased with reduction of the mean RNFLT (arteries: r = 0.718 p field loss, may be explained by a reduction of the retinal metabolic demand with progressive loss of neuronal tissue in glaucoma. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  13. Context-dependent effects of cold stress on behavioral, physiological, and life-history traits of the red flour beetle.

    Science.gov (United States)

    Scharf, Inon; Wertheimer, Keren-Or; Xin, Joy Lim; Gilad, Tomer; Goldenberg, Inna; Subach, Aziz

    2017-06-20

    Animals are exposed in nature to a variety of stressors. While stress is generally harmful, mild stress can also be beneficial and contribute to reproduction and survival. We studied the effect of five cold shock events versus a single cold shock and a control group, representing three levels of stress (harsh, mild, and no stress), on behavioral, physiological, and life-history traits of the red flour beetle (Tribolium castaneum, Herbst 1797). Beetles exposed to harsh cold stress were less active than a control group: they moved less and failed more frequently to detect a food patch. Their probability to mate was also lower. Beetle pairs exposed to harsh cold stress frequently failed to reproduce at all, and if reproducing, females laid fewer eggs, which were, as larvae in mid-development, smaller than those in the control group. However, harsh cold stress led to improved female starvation tolerance, probably due to enhanced lipid accumulation. Harsh cold shock also improved tolerance to an additional cold shock compared to the control. Finally, a single cold shock event negatively affected fewer measured response variables than the harsh cold stress, but also enhanced neither starvation tolerance nor tolerance to an additional cold shock. The consequences of a harsher cold stress are thus not solely detrimental but might even enhance survival under stressful conditions. Under benign conditions, nevertheless, harsh stress impedes beetle performance. The harsh stress probably shifted the balance point of the survival-reproduction trade-off, a shift that did not take place following exposure to mild stress. © 2017 Institute of Zoology, Chinese Academy of Sciences.

  14. Pollutant Dehalogenation Capability May Depend on the Trophic Evolutionary History of the Organism: PBDEs in Freshwater Food Webs

    Science.gov (United States)

    Bartrons, Mireia; Grimalt, Joan O.; de Mendoza, Guillermo; Catalan, Jordi

    2012-01-01

    Organohalogen compounds are some of the most notorious persistent pollutants disturbing the Earth biosphere. Although human-made, these chemicals are not completely alien to living systems. A large number of natural organohalogens, part of the secondary metabolism, are involved in chemical trophic interactions. Surprisingly, the relationship between organisms’ trophic position and synthetic organohalogen biotransformation capability has not been investigated. We studied the case for polybromodiphenyl ethers (PBDE), a group of flame-retardants of widespread use in the recent years, in aquatic food webs from remote mountain lakes. These relatively simple ecosystems only receive pollution by atmospheric transport. A large predominance of the PBDE congener currently in use in Europe, BDE-209, largely dominated the PBDE composition of the basal resources of the food web. In contrast, primary consumers (herbivores and detritivores) showed a low proportion of BDE-209, and dominance of several less brominated congeners (e.g. BDE-100, BDE47). Secondary consumers (predators) showed large biomagnification of BDE-209 compare to other congeners. Finally, top predator fish characterized by low total PBDE concentrations. Examination of the bromine stable isotopic composition indicates that primary consumers showed higher PBDE biotransformation capability than secondary consumers. We suggest that the evolutionary response of primary consumers to feeding deterrents would have pre-adapted them for PBDE biotransformation. The observed few exceptions, some insect taxa, can be interpreted in the light of the trophic history of the evolutionary lineage of the organisms. Bromine isotopic composition in fish indicates that low PBDE values are due to not only biotransformation but also to some other process likely related to transport. Our finding illustrates that organohalogen compounds may strongly disturb ecosystems even at low concentrations, since the species lacking or having

  15. Pollutant dehalogenation capability may depend on the trophic evolutionary history of the organism: PBDEs in freshwater food webs.

    Directory of Open Access Journals (Sweden)

    Mireia Bartrons

    Full Text Available Organohalogen compounds are some of the most notorious persistent pollutants disturbing the Earth biosphere. Although human-made, these chemicals are not completely alien to living systems. A large number of natural organohalogens, part of the secondary metabolism, are involved in chemical trophic interactions. Surprisingly, the relationship between organisms' trophic position and synthetic organohalogen biotransformation capability has not been investigated. We studied the case for polybromodiphenyl ethers (PBDE, a group of flame-retardants of widespread use in the recent years, in aquatic food webs from remote mountain lakes. These relatively simple ecosystems only receive pollution by atmospheric transport. A large predominance of the PBDE congener currently in use in Europe, BDE-209, largely dominated the PBDE composition of the basal resources of the food web. In contrast, primary consumers (herbivores and detritivores showed a low proportion of BDE-209, and dominance of several less brominated congeners (e.g. BDE-100, BDE47. Secondary consumers (predators showed large biomagnification of BDE-209 compare to other congeners. Finally, top predator fish characterized by low total PBDE concentrations. Examination of the bromine stable isotopic composition indicates that primary consumers showed higher PBDE biotransformation capability than secondary consumers. We suggest that the evolutionary response of primary consumers to feeding deterrents would have pre-adapted them for PBDE biotransformation. The observed few exceptions, some insect taxa, can be interpreted in the light of the trophic history of the evolutionary lineage of the organisms. Bromine isotopic composition in fish indicates that low PBDE values are due to not only biotransformation but also to some other process likely related to transport. Our finding illustrates that organohalogen compounds may strongly disturb ecosystems even at low concentrations, since the species lacking

  16. Evolutionary history of a vanishing radiation: isolation-dependent persistence and diversification in Pacific Island partulid tree snails.

    Science.gov (United States)

    Lee, Taehwan; Li, Jingchun; Churchill, Celia K C; Foighil, Diarmaid Ó

    2014-09-24

    Partulid tree snails are endemic to Pacific high islands and have experienced extraordinary rates of extinction in recent decades. Although they collectively range across a 10,000 km swath of Oceania, half of the family's total species diversity is endemic to a single Eastern Pacific hot spot archipelago (the Society Islands) and all three partulid genera display highly distinctive distributions. Our goal was to investigate broad scale (range wide) and fine scale (within-Society Islands) molecular phylogenetic relationships of the two widespread genera, Partula and Samoana. What can such data tell us regarding the genesis of such divergent generic distribution patterns, and nominal species diversity levels across Oceania? Museum, captive (zoo) and contemporary field specimens enabled us to genotype 54 of the ~120 recognized species, including many extinct or extirpated taxa, from 14 archipelagoes. The genera Partula and Samoana are products of very distinct diversification processes. Originating at the western edge of the familial range, the derived genus Samoana is a relatively recent arrival in the far eastern archipelagoes (Society, Austral, Marquesas) where it exhibits a stepping-stone phylogenetic pattern and has proven adept at both intra-and inter- archipelago colonization. The pronounced east-west geographic disjunction exhibited by the genus Partula stems from a much older long-distance dispersal event and its high taxonomic diversity in the Society Islands is a product of a long history of within-archipelago diversification. The central importance of isolation for partulid lineage persistence and diversification is evident in time-calibrated phylogenetic trees that show that remote archipelagoes least impacted by continental biotas bear the oldest clades and/or the most speciose radiations. In contemporary Oceania, that isolation is being progressively undermined and these tree snails are now directly exposed to introduced continental predators

  17. Deoxyribonucleoprotein structure and radiation injury - Cellular radiosensitivity is determined by LET-infinity-dependent DNA damage in hydrated deoxyribonucleoproteins and the extent of its repair

    Science.gov (United States)

    Lett, J. T.; Peters, E. L.

    1992-01-01

    Until recently, OH radicals formed in bulk nuclear water were believed to be the major causes of DNA damage that results in cell death, especially for sparsely ionizing radiations. That hypothesis has now been challenged, if not refuted. Lethal genomic DNA damage is determined mainly by energy deposition in deoxyribonucleoproteins, and their hydration shells, and charge (energy) transfer processes within those structures.

  18. THE MASS-DEPENDENT CLUSTERING HISTORY OF K-SELECTED GALAXIES AT z < 4 IN THE SXDS/UDS FIELD

    International Nuclear Information System (INIS)

    Furusawa, Junko; Sekiguchi, Kazuhiro; Takata, Tadafumi; Furusawa, Hisanori; Shimasaku, Kazuhiro; Simpson, Chris; Akiyama, Masayuki

    2011-01-01

    We investigate mass-dependent galaxy evolution based on a large sample of (more than 50,000) K-band selected galaxies in a multi-wavelength catalog of the Subaru/XMM-Newton Deep Survey and the UKIRT Infrared Deep Sky Survey/Ultra Deep Survey. We employ optical to near-infrared photometry to determine photometric redshifts of these galaxies. Then, we estimate the stellar mass of our sample galaxies using a standard fitting procedure as we used for estimation of the photometric redshift. From the sample galaxies, we obtain the stellar mass function of galaxies and the cosmic stellar mass density up to z ∼ 4. Our results are consistent with previous studies and we find a considerable number of low-mass galaxies (M * ∼ 10 10.5 ) at the redshift range 3 14 M sun ) to low (10 13 M sun ) with decreasing redshift at around z ∼ 2. We also find some high-mass density regions of massive galaxies at 1.4 ≤ z < 2.5 in our sample. These concentrations of massive galaxies may be candidate progenitors of the present-day clusters of galaxies. At this redshift range, massive star-forming galaxies are the dominant population making up the structures and the passively evolving galaxies show stronger clustering and they may have formed earlier than those star-forming galaxies.

  19. Inhibition of the HDAC/Suv39/G9a pathway restores the expression of DNA damage-dependent major histocompatibility complex class I-related chain A and B in cancer cells.

    Science.gov (United States)

    Nakajima, Nakako Izumi; Niimi, Atsuko; Isono, Mayu; Oike, Takahiro; Sato, Hiro; Nakano, Takashi; Shibata, Atsushi

    2017-08-01

    Immunotherapy is expected to be promising as a next generation cancer therapy. Immunoreceptors are often activated constitutively in cancer cells, however, such levels of ligand expression are not effectively recognized by the native immune system due to tumor microenvironmental adaptation. Studies have demonstrated that natural-killer group 2, member D (NKG2D), a major activating immunoreceptor, responds to DNA damage. The upregulation of major histocompatibility complex class I-related chain A and B (MICA/B) (members of NKG2D ligands) expression after DNA damage is associated with NK cell-mediated killing of cancer cells. However, the regulation of DNA damage-induced MICA/B expression has not been fully elucidated in the context of the types of cancer cell lines. In the present study, we found that MICA/B expression varied between cancer cell lines after DNA damage. Screening in terms of chromatin remodeling identified that inhibitors related to chromatin relaxation via post-translational modification on histone H3K9, i.e. HDAC, Suv39 or G9a inhibition, restored DNA damage-dependent MICA/B expression in insensitive cells. In addition, we revealed that the restored MICA/B expression was dependent on ATR as well as E2F1, a transcription factor. We further revealed that low‑dose treatment of an HDAC inhibitor was sufficient to restore MICA/B expression in insensitive cells. Finally, we demonstrated that HDAC inhibition restored DNA damage‑dependent cytotoxic NK activity against insensitive cells. Thus, the present study revealed that DNA damage‑dependent MICA/B expression in insensitive cancer cells can be restored by chromatin relaxation via the HDAC/Suv39/G9a pathway. Collectively, manipulation of chromatin status by therapeutic cancer drugs may potentiate the antitumor effect by enhancing immune activation following radiotherapy and DNA damage-associated chemotherapy.

  20. Numerical analysis of breakdown dynamics dependence on pulse width in laser-induced damage in fused silica: Role of optical system

    Directory of Open Access Journals (Sweden)

    Kholoud A. Hamam

    2018-06-01

    Full Text Available We report a numerical investigation of the breakdown and damage in fused silica caused by ultra-short laser pulses. The study based on a modified model (Gaabour et al., 2012 that solves the rate equation numerically for the electron density evolution during the laser pulse, under the combined effect of both multiphoton and electron impact ionization processes. Besides, electron loss processes due to diffusion out of the focal volume and recombination are also considered in this analysis. The model is applied to investigate the threshold intensity dependence on laser pulse width in the experimental measurements that are given by Liu et al. (2005. In this experiment, a Ti-sapphire laser source operating at 800 nm with pulse duration varies between 240 fs and 2.5 ps is used to irradiate a bulk of fused silica with dimensions 10 × 5 × 3 mm. The laser beam was focused into the bulk using two optical systems with effective numerical apertures (NA 0.126 and 0.255 to give beam spot radius at the focus of the order 2.0 μm and 0.95 μm respectively. Reasonable agreement between the calculated thresholds and the measured ones is attained. Moreover, a study is performed to examine the respective role of the physical processes of the breakdown of fused silica in relation to the pulse width and focusing optical system. The analysis revealed a real picture of the location and size of the generated plasma. Keywords: Ultra-short laser pulses, Ablation mechanisms, Electron density, Electron loss processes, Avalanche ionization, Breakdown threshold

  1. Match or mismatch: the influence of phenology on size-dependent life history and divergence in population structure

    Science.gov (United States)

    Borcherding, Jost; Beeck, Peter; DeAngelis, Donald L.; Scharf, Werner R.

    2010-01-01

    age cohort of the predator. 6. The results demonstrate that the switch between competitive interactions and a predator-prey relationship depended on phenology. This resulted in pronounced size differences in the YOY age cohort, which had far-reaching consequences for the entire predator population.

  2. NO accumulation alleviates H2 O2 -dependent oxidative damage induced by Ca(NO3 )2 stress in the leaves of pumpkin-grafted cucumber seedlings.

    Science.gov (United States)

    Li, Lin; Shu, Sheng; Xu, Qing; An, Ya-Hong; Sun, Jin; Guo, Shi-Rong

    2017-05-01

    Nitric oxide (NO) and hydrogen peroxide (H 2 O 2 ), two important signaling molecules, are stimulated in plants by abiotic stresses. In this study, we investigated the role of NO and its interplay with H 2 O 2 in the response of self-grafted (S-G) and salt-tolerant pumpkin-grafted (Cucurbita maxima × C. moschata) cucumber seedlings to 80 mM Ca(NO 3 ) 2 stress. Endogenous NO and H 2 O 2 production in S-G seedlings increased in a time-dependent manner, reaching maximum levels after 24 h of Ca(NO 3 ) 2 stress. In contrast, a transient increase in NO production, accompanied by H 2 O 2 accumulation, was observed at 2 h in rootstock-grafted plants. N w -Nitro-l-Arg methyl ester hydrochloride (l-NAME), an inhibitor of nitric oxide synthase (NOS), tungstate, an inhibitor of nitrate reductase (NR), and 2-(4-carboxyphenyl)-4,4,5,5-tetramethy-limidazoline-1-oxyl-3-oxide (cPTIO), a scavenger of NO, were found to significantly inhibit NO accumulation induced by salt stress in rootstock-grafted seedlings. H 2 O 2 production was unaffected by these stress conditions. Ca(NO 3 ) 2 stress-induced NO accumulation was blocked by pretreatment with an H 2 O 2 scavenger (dimethylthiourea, DMTU) and an inhibitor of NADPH oxidase (diphenyleneiodonium, DPI). In addition, maximum quantum yield of PSII (Fv/Fm), as well as the activities and transcript levels of antioxidant enzymes, were significantly decreased by salt stress in rootstock grafted seedlings after pretreatment with these above inhibitors; antioxidant enzyme transcript levels and activities were higher in rootstock-grafted seedlings compared with S-G seedlings. These results suggest that rootstock grafting could alleviate the oxidative damage induced by Ca(NO 3 ) 2 stress in cucumber seedlings, an effect that may be attributable to the involvement of NO in H 2 O 2 -dependent antioxidative metabolism. © 2016 Scandinavian Plant Physiology Society.

  3. Heat indicators of oxidative stress, inflammation and metal transport show dependence of cadmium pollution history in the liver of female zebrafish.

    Science.gov (United States)

    Zhu, Qing-Ling; Guo, Sai-Nan; Yuan, Shuang-Shuang; Lv, Zhen-Ming; Zheng, Jia-Lang; Xia, Hu

    2017-10-01

    Environmental stressors such as high temperature and metal exposure may occur sequentially, simultaneously, previously in aquatic ecosystems. However, information about whether responses to high temperature depend on Cd exposure history is still unknown in fish. Zebrafish were exposed to 0 (group 1), 2.5 (group 2) and 5μg/L (group 3) cadmium (Cd) for 10 weeks, and then each group was subjected to Cd-free water maintained at 26°C and 32°C for 7days respectively. 26 indicators were used to compare differences between 26°C and 32°C in the liver of female zebrafish, including 5 biochemical indicators (activity of Cu/Zn-SOD, CAT and iNOS; LPO; MT protein), 8 molecular indicators of oxidative stress (mRNA levels of Nrf2, Cu/Zn-SOD, CAT, HSF1, HSF2, HSP70, MTF-1 and MT), 5 molecular indicators of inflammation (mRNA levels of IL-6, IL-1β, TNF-α, iNOS and NF-κB), 8 molecular indicators of metal transport (mRNA levels of, ZnT1, ZnT5, ZIP8, ZIP10, ATP7A, ATP7B and CTR1). All biochemical indicators were unchanged in group 1 and changed in group 2 and 3. Contrarily, differences were observed in almost all of molecular indicators of inflammation and metal transport in group 1, about half in group 2, and few in group 3. We also found that all molecular indicators of oxidative stress in group 2 and fewer in group 1 and 3 were significantly affected by heat. Our data indicated that heat indicators of oxidative stress, inflammation and metal transport showed dependence of previous cadmium exposure in the liver of zebrafish, emphasizing metal pollution history should be carefully considered when evaluating heat stress in fish. Copyright © 2017. Published by Elsevier B.V.

  4. Stress-related salivary alpha-amylase (sAA) activity in alcohol dependent patients with and without a history of childhood maltreatment.

    Science.gov (United States)

    Muehlhan, Markus; Höcker, Anja; Höfler, Michael; Wiedemann, Klaus; Barnow, Sven; Schäfer, Ingo

    2017-06-01

    Alcohol-dependent (AD) patients with a history of childhood maltreatment (CM) have shown a more severe clinical profile and a higher risk of relapse than those without CM. It was hypothesized that stress responsivity plays an important role in moderating the relationship between CM and AD. Surprisingly, systematic investigations about the stress responsivity in AD patients with CM are rare. This study compared physiological and subjective stress responses in AD patients with and without CM as well as in healthy controls with and without CM. A total of 130 participants performed the Trier Social Stress Test (TSST). Physiological stress reactivity related to the noradrenergic system was assessed by salivary alpha-amylase (sAA) activity. Subjective ratings of anxiety, nervousness, distress, and mood were rated on visual analogue scales. AD patients showed significantly lower stress-related sAA activity than healthy controls (p ≤ 0.024; z ≥ 1.97). A different pattern was found in the subjective ratings. In particular, anticipatory anxiety revealed a clear effect of CM (p ≤ 0.005; z ≥ 2.43) but no difference between AD patients and healthy controls (p > 0.05). After the TSST, distress ratings differed between AD patients with CM and AD patients without CM (p ≤ 0.009; z ≥ 2.61). The discrepancy between physiological responsivity and subjective stress experiences may account for an increased inability to cope with stressful situations, which in turn might explain the enhanced risk of relapse in AD patients with a history of CM during early abstinence.

  5. DVC1 (C1orf124) is a DNA damage-targeting p97 adaptor that promotes ubiquitin-dependent responses to replication blocks

    DEFF Research Database (Denmark)

    Mosbech, Anna; Gibbs-Seymour, Ian; Kagias, Konstantinos

    2012-01-01

    Ubiquitin-mediated processes orchestrate critical DNA-damage signaling and repair pathways. We identify human DVC1 (C1orf124; Spartan) as a cell cycle-regulated anaphase-promoting complex (APC) substrate that accumulates at stalled replication forks. DVC1 recruitment to sites of replication stress...... synthesis (TLS) DNA polymerase η (Pol η) from monoubiquitylated PCNA. DVC1 knockdown enhances UV light-induced mutagenesis, and depletion of human DVC1 or the Caenorhabditis elegans ortholog DVC-1 causes hypersensitivity to replication stress-inducing agents. Our findings establish DVC1 as a DNA damage...

  6. P2X receptor-dependent erythrocyte damage by α-hemolysin from Escherichia coli triggers phagocytosis by THP-1 cells

    DEFF Research Database (Denmark)

    Fagerberg, Steen Kåre; Skals, Marianne Gerberg; Leipziger, Jens Georg

    2013-01-01

    , which is known to be a keen trigger for phagocytosis. We hypothesize that exposure to HlyA elicits removal of the damaged erythrocytes by phagocytic cells. Cultured THP-1 cells as a model for erythrocytal phagocytosis was verified by a variety of methods, including live cell imaging. We consistently...

  7. Efficacy of 670 nm Light Therapy to Protect against Photoreceptor Cell Death Is Dependent on the Severity of Damage

    Directory of Open Access Journals (Sweden)

    Joshua A. Chu-Tan

    2016-01-01

    Full Text Available Photobiomodulation at a wavelength of 670 nm has been shown to be effective in preventing photoreceptor cell death in the retina. We treated Sprague-Dawley (SD rats with varying doses of 670 nm light (9; 18; 36; 90 J/cm2 before exposing them to different intensities of damaging white light (750; 1000; 1500 lux. 670 nm light exhibited a biphasic response in its amelioration of cell death in light-induced degeneration in vivo. Lower light damage intensities required lower doses of 670 nm light to reduce TUNEL cell death. At higher damage intensities, the highest dose of 670 nm light showed protection. In vitro, the Seahorse XFe96 Extracellular Flux Analyzer revealed that 670 nm light directly influences mitochondrial metabolism by increasing the spare respiratory capacity of mitochondria in 661 W photoreceptor-like cells in light damaged conditions. Our findings further support the use of 670 nm light as an effective treatment against retinal degeneration as well as shedding light on the mechanism of protection through the increase of the mitochondrial spare respiratory capacity.

  8. Bayesian deterministic decision making: A normative account of the operant matching law and heavy-tailed reward history dependency of choices

    Directory of Open Access Journals (Sweden)

    Hiroshi eSaito

    2014-03-01

    Full Text Available The decision making behaviors of humans and animals adapt and then satisfy an ``operant matching law'' in certain type of tasks. This was first pointed out by Herrnstein in his foraging experiments on pigeons. The matching law has been one landmark for elucidating the underlying processes of decision making and its learning in the brain. An interesting question is whether decisions are made deterministically or probabilistically. Conventional learning models of the matching law are based on the latter idea; they assume that subjects learn choice probabilities of respective alternatives and decide stochastically with the probabilities. However, it is unknown whether the matching law can be accounted for by a deterministic strategy or not. To answer this question, we propose several deterministic Bayesian decision making models that have certain incorrect beliefs about an environment. We claim that a simple model produces behavior satisfying the matching law in static settings of a foraging task but not in dynamic settings. We found that the model that has a belief that the environment is volatile works well in the dynamic foraging task and exhibits undermatching, which is a slight deviation from the matching law observed in many experiments. This model also demonstrates the double-exponential reward history dependency of a choice and a heavier-tailed run-length distribution, as has recently been reported in experiments on monkeys.

  9. Prediction of crack propagation and arrest in X100 natural gas transmission pipelines with a strain rate dependent damage model (SRDD). Part 2: Large scale pipe models with gas depressurisation

    International Nuclear Information System (INIS)

    Oikonomidis, F.; Shterenlikht, A.; Truman, C.E.

    2014-01-01

    Part 1 of this paper described a specimen for the measurement of high strain rate flow and fracture properties of pipe material and for tuning a strain rate dependent damage model (SRDD). In part 2 the tuned SRDD model is used for the simulation of axial crack propagation and arrest in X100 natural gas pipelines. Linear pressure drop model was adopted behind the crack tip, and an exponential gas depressurisation model was used ahead of the crack tip. The model correctly predicted the crack initiation (burst) pressure, the crack speed and the crack arrest length. Strain rates between 1000 s −1 and 3000 s −1 immediately ahead of the crack tip are predicted, giving a strong indication that a strain rate material model is required for the structural integrity assessment of the natural gas pipelines. The models predict the stress triaxiality of about 0.65 for at least 1 m ahead of the crack tip, gradually dropping to 0.5 at distances of about 5–7 m ahead of the crack tip. Finally, the models predicted a linear drop in crack tip opening angle (CTOA) from about 11−12° at the onset of crack propagation down to 7−8° at crack arrest. Only the lower of these values agree with those reported in the literature for quasi-static measurements. This discrepancy might indicate substantial strain rate dependence in CTOA. - Highlights: • Finite element simulations of 3 burst tests of X100 pipes are detailed. • Strain rate dependent damage model, tuned on small scale X100 samples, was used. • The models correctly predict burst pressure, crack speed and crack arrest length. • The model predicts a crack length dependent critical CTOA. • The strain rate dependent damage model is verified as mesh independent

  10. IFNγ induces oxidative stress, DNA damage and tumor cell senescence via TGFβ/SMAD signaling-dependent induction of Nox4 and suppression of ANT2

    Czech Academy of Sciences Publication Activity Database

    Hubáčková, Soňa; Kučerová, Alena; Michlits, Georg; Kyjacová, Lenka; Reiniš, Milan; Korolov, Oleksandr; Bartek, Jiří; Hodný, Zdeněk

    2016-01-01

    Roč. 35, č. 10 (2016), s. 1236-1249 ISSN 0950-9232 R&D Projects: GA ČR GA13-17658S; GA MZd NT14461; GA AV ČR(CZ) L200521301 Institutional support: RVO:68378050 Keywords : IFNγ * DNA damage * TGFβ/SMAD signaling * Nox4 Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 7.519, year: 2016

  11. Damage accumulation in nitrogen implanted 6H-SiC: Dependence on the direction of ion incidence and on the ion fluence

    International Nuclear Information System (INIS)

    Zolnai, Z.; Ster, A.; Khanh, N. Q.; Battistig, G.; Lohner, T.; Gyulai, J.; Kotai, E.; Posselt, M.

    2007-01-01

    The influence of crystallographic orientation and ion fluence on the shape of damage distributions induced by 500 keV N + implantation at room temperature into 6H-SiC is investigated. The irradiation was performed at different tilt angles between 0 degree sign and 4 degree sign with respect to the crystallographic axis in order to consider the whole range of beam alignment from channeling to random conditions. The applied implantation fluence range was 2.5x10 14 -3x10 15 cm -2 . A special analytical method, 3.55 MeV 4 He + ion backscattering analysis in combination with channeling technique (BS/C), was employed to measure the disorder accumulation simultaneously in the Si and C sublattices of SiC with good depth resolution. For correct energy to depth conversion in the BS/C spectra, the average electronic energy loss per analyzing He ion for the axial channeling direction was determined. It was found that the tilt angle of nitrogen implantation has strong influence on the shape of the induced disorder profiles. Significantly lower disorder was found for channeling than for random irradiation. Computer simulation of the measured BS/C spectra showed the presence of a simple defect structure in weakly damaged samples and suggested the formation of a complex disorder state for higher disorder levels. Full-cascade atomistic computer simulation of the ion implantation process was performed to explain the differences in disorder accumulation on the Si and C sublattices. The damage buildup mechanism was interpreted with the direct-impact, defect-stimulated amorphization model in order to understand damage formation and to describe the composition of structural disorder versus the ion fluence and the implantation tilt angle

  12. Lithium Chloride Dependent Glycogen Synthase Kinase 3 Inactivation Links Oxidative DNA Damage, Hypertrophy and Senescence in Human Articular Chondrocytes and Reproduces Chondrocyte Phenotype of Obese Osteoarthritis Patients.

    Directory of Open Access Journals (Sweden)

    Serena Guidotti

    Full Text Available Recent evidence suggests that GSK3 activity is chondroprotective in osteoarthritis (OA, but at the same time, its inactivation has been proposed as an anti-inflammatory therapeutic option. Here we evaluated the extent of GSK3β inactivation in vivo in OA knee cartilage and the molecular events downstream GSK3β inactivation in vitro to assess their contribution to cell senescence and hypertrophy.In vivo level of phosphorylated GSK3β was analyzed in cartilage and oxidative damage was assessed by 8-oxo-deoxyguanosine staining. The in vitro effects of GSK3β inactivation (using either LiCl or SB216763 were evaluated on proliferating primary human chondrocytes by combined confocal microscopy analysis of Mitotracker staining and reactive oxygen species (ROS production (2',7'-dichlorofluorescin diacetate staining. Downstream effects on DNA damage and senescence were investigated by western blot (γH2AX, GADD45β and p21, flow cytometric analysis of cell cycle and light scattering properties, quantitative assessment of senescence associated β galactosidase activity, and PAS staining.In vivo chondrocytes from obese OA patients showed higher levels of phosphorylated GSK3β, oxidative damage and expression of GADD45β and p21, in comparison with chondrocytes of nonobese OA patients. LiCl mediated GSK3β inactivation in vitro resulted in increased mitochondrial ROS production, responsible for reduced cell proliferation, S phase transient arrest, and increase in cell senescence, size and granularity. Collectively, western blot data supported the occurrence of a DNA damage response leading to cellular senescence with increase in γH2AX, GADD45β and p21. Moreover, LiCl boosted 8-oxo-dG staining, expression of IKKα and MMP-10.In articular chondrocytes, GSK3β activity is required for the maintenance of proliferative potential and phenotype. Conversely, GSK3β inactivation, although preserving chondrocyte survival, results in functional impairment via

  13. Lithium Chloride Dependent Glycogen Synthase Kinase 3 Inactivation Links Oxidative DNA Damage, Hypertrophy and Senescence in Human Articular Chondrocytes and Reproduces Chondrocyte Phenotype of Obese Osteoarthritis Patients.

    Science.gov (United States)

    Guidotti, Serena; Minguzzi, Manuela; Platano, Daniela; Cattini, Luca; Trisolino, Giovanni; Mariani, Erminia; Borzì, Rosa Maria

    2015-01-01

    Recent evidence suggests that GSK3 activity is chondroprotective in osteoarthritis (OA), but at the same time, its inactivation has been proposed as an anti-inflammatory therapeutic option. Here we evaluated the extent of GSK3β inactivation in vivo in OA knee cartilage and the molecular events downstream GSK3β inactivation in vitro to assess their contribution to cell senescence and hypertrophy. In vivo level of phosphorylated GSK3β was analyzed in cartilage and oxidative damage was assessed by 8-oxo-deoxyguanosine staining. The in vitro effects of GSK3β inactivation (using either LiCl or SB216763) were evaluated on proliferating primary human chondrocytes by combined confocal microscopy analysis of Mitotracker staining and reactive oxygen species (ROS) production (2',7'-dichlorofluorescin diacetate staining). Downstream effects on DNA damage and senescence were investigated by western blot (γH2AX, GADD45β and p21), flow cytometric analysis of cell cycle and light scattering properties, quantitative assessment of senescence associated β galactosidase activity, and PAS staining. In vivo chondrocytes from obese OA patients showed higher levels of phosphorylated GSK3β, oxidative damage and expression of GADD45β and p21, in comparison with chondrocytes of nonobese OA patients. LiCl mediated GSK3β inactivation in vitro resulted in increased mitochondrial ROS production, responsible for reduced cell proliferation, S phase transient arrest, and increase in cell senescence, size and granularity. Collectively, western blot data supported the occurrence of a DNA damage response leading to cellular senescence with increase in γH2AX, GADD45β and p21. Moreover, LiCl boosted 8-oxo-dG staining, expression of IKKα and MMP-10. In articular chondrocytes, GSK3β activity is required for the maintenance of proliferative potential and phenotype. Conversely, GSK3β inactivation, although preserving chondrocyte survival, results in functional impairment via induction of

  14. Age-dependent loss of cholinergic neurons in learning and memory-related brain regions and impaired learning in SAMP8 mice with trigeminal nerve damage

    Institute of Scientific and Technical Information of China (English)

    Yifan He; Jihong Zhu; Fang Huang; Liu Qin; Wenguo Fan; Hongwen He

    2014-01-01

    The tooth belongs to the trigeminal sensory pathway. Dental damage has been associated with impairments in the central nervous system that may be mediated by injury to the trigeminal nerve. In the present study, we investigated the effects of damage to the inferior alveolar nerve, an important peripheral nerve in the trigeminal sensory pathway, on learning and memory be-haviors and structural changes in related brain regions, in a mouse model of Alzheimer’s disease. Inferior alveolar nerve transection or sham surgery was performed in middle-aged (4-month-old) or elderly (7-month-old) senescence-accelerated mouse prone 8 (SAMP8) mice. When the middle-aged mice reached 8 months (middle-aged group 1) or 11 months (middle-aged group 2), and the elderly group reached 11 months, step-down passive avoidance and Y-maze tests of learn-ing and memory were performed, and the cholinergic system was examined in the hippocampus (Nissl staining and acetylcholinesterase histochemistry) and basal forebrain (choline acetyltrans-ferase immunohistochemistry). In the elderly group, animals that underwent nerve transection had fewer pyramidal neurons in the hippocampal CA1 and CA3 regions, fewer cholinergic ifbers in the CA1 and dentate gyrus, and fewer cholinergic neurons in the medial septal nucleus and vertical limb of the diagonal band, compared with sham-operated animals, as well as showing impairments in learning and memory. Conversely, no signiifcant differences in histology or be-havior were observed between middle-aged group 1 or group 2 transected mice and age-matched sham-operated mice. The present ifndings suggest that trigeminal nerve damage in old age, but not middle age, can induce degeneration of the septal-hippocampal cholinergic system and loss of hippocampal pyramidal neurons, and ultimately impair learning ability. Our results highlight the importance of active treatment of trigeminal nerve damage in elderly patients and those with Alzheimer’s disease, and

  15. Cosmic growth history and expansion history

    International Nuclear Information System (INIS)

    Linder, Eric V.

    2005-01-01

    The cosmic expansion history tests the dynamics of the global evolution of the universe and its energy density contents, while the cosmic growth history tests the evolution of the inhomogeneous part of the energy density. Precision comparison of the two histories can distinguish the nature of the physics responsible for the accelerating cosmic expansion: an additional smooth component--dark energy--or a modification of the gravitational field equations. With the aid of a new fitting formula for linear perturbation growth accurate to 0.05%-0.2%, we separate out the growth dependence on the expansion history and introduce a new growth index parameter γ that quantifies the gravitational modification

  16. Radiation-induced DNA damage in tumors and normal tissues. III. Oxygen dependence of the formation of strand breaks and DNA-protein crosslinks

    International Nuclear Information System (INIS)

    Zhang, H.; Wallen, C.A.; Wheeler, K.T.; Joch, C.J.

    1995-01-01

    Results from several laboratories, including ours, have suggested that measurements of radiation-induced DNA strand breaks and DNA-protein crosslinks (DPCs) may be used to estimate the hypoxic fraction or fractional hypoxic volume of tumors and normal tissues. This suggestion has been predicated on both published and nonpublished information that (1) the oxygen dependence of the formation of strand breaks in irradiated mammalian cells is similar to the oxygen dependence of radiation-produced cell killing, and (2) the oxygen dependence of the formation of DPCs in irradiated mammalian cells is the mirror image of the oxygen dependence of radiation-induced cell killing. However, the published studies that attempted to determine the relationship between the oxygen dependence of the formation of strand breaks and the radiation sensitivity of mammalian cells were not performed at 37 degrees C, the exact oxygen concentrations were not always known, and the results were conflicting. In addition, most of the data on the oxygen dependence of the formation of DPCs are unpublished. Consequently, we have undertaken a comprehensive investigation of one cell line, 9L/Ro rat brain tumor cells, to determine if the shape of the oxygen dependence curve and the K m value for radiation-induced strand breaks and DPCs were similar when 9L cells were irradiated under both ideal gas-liquid equilibrium conditions at 4 degrees C and nonideal gas-liquid equilibrium conditions at 37 degrees C. At 4 degrees C under ideal gas-liquid equilibrium conditions, the K m for the formation of strand breaks was approximately 0.0045 mM, and Km for radiation sensitivity was approximately 0.005mM. A similar comparison for the formation of DPCs at 4 degrees C could not be made, because the efficiency of the formation of DPC was much lower at 4 degrees C than at 37 degrees C. 30 refs., 3 figs

  17. Damage instability and Earthquake nucleation

    Science.gov (United States)

    Ionescu, I. R.; Gomez, Q.; Campillo, M.; Jia, X.

    2017-12-01

    Earthquake nucleation (initiation) is usually associated to the loss of the stability of the geological structure under a slip-weakening friction acting on the fault. The key parameters involved in the stability of the fault are the stress drop, the critical slip distance but also the elastic stiffness of the surrounding materials (rocks). We want to explore here how the nucleation phenomena are correlated to the material softening during damage accumulation by dynamic and/or quasi-static processes. Since damage models are describing micro-cracks growth, which is generally an unstable phenomenon, it is natural to expect some loss of stability on the associated micro-mechanics based models. If the model accurately captures the material behavior, then this can be due to the unstable nature of the brittle material itself. We obtained stability criteria at the microscopic scale, which are related to a large class of damage models. We show that for a given continuous strain history the quasi-static or dynamic problems are instable or ill-posed (multiplicity of material responses) and whatever the selection rule is adopted, shocks (time discontinuities) will occur. We show that the quasi-static equilibria chosen by the "perfect delay convention" is always stable. These stability criteria are used to analyze how NIC (Non Interacting Crack) effective elasticity associated to "self similar growth" model work in some special configurations (one family of micro-cracks in mode I, II and III and in plane strain or plain stress). In each case we determine a critical crack density parameter and critical micro-crack radius (length) which distinguish between stable and unstable behaviors. This critical crack density depends only on the chosen configuration and on the Poisson ratio.

  18. DNA damage and polyploidization.

    Science.gov (United States)

    Chow, Jeremy; Poon, Randy Y C

    2010-01-01

    A growing body of evidence indicates that polyploidization triggers chromosomal instability and contributes to tumorigenesis. DNA damage is increasingly being recognized for its roles in promoting polyploidization. Although elegant mechanisms known as the DNA damage checkpoints are responsible for halting the cell cycle after DNA damage, agents that uncouple the checkpoints can induce unscheduled entry into mitosis. Likewise, defects of the checkpoints in several disorders permit mitotic entry even in the presence of DNA damage. Forcing cells with damaged DNA into mitosis causes severe chromosome segregation defects, including lagging chromosomes, chromosomal fragments and chromosomal bridges. The presence of these lesions in the cleavage plane is believed to abort cytokinesis. It is postulated that if cytokinesis failure is coupled with defects of the p53-dependent postmitotic checkpoint pathway, cells can enter S phase and become polyploids. Progress in the past several years has unraveled some of the underlying principles of these pathways and underscored the important role of DNA damage in polyploidization. Furthermore, polyploidization per se may also be an important determinant of sensitivity to DNA damage, thereby may offer an opportunity for novel therapies.

  19. Modeling of DNA damage-cluster, cell-cycle and repair pathway dependent radiosensitivity after low- and high-LET irradiation; Modellierung der DNA-Schadenscluster-, Zellzyklus- und Reparaturweg-abhaengigen Strahlenempfindlichkeit nach niedrig- und hoch-LET-Bestrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, Paul

    2017-07-17

    This work focuses on modeling of the effects of ionizing radiation on cells, primarily on, the influence of the DNA repair pathway availability and the radiation quality on the cell-survival probability. The availability of DNA repair pathways depends on the replication state and defects of the DNA repair pathways. The radiation quality manifests itself in the microscopic ionization pattern. The Giant LOop Binary LEsion (GLOBLE) model and the Local Effect Model (LEM) describe the cell-survival after photon and ion irradiation, respectively. Both models assume that cell survival can be modeled based on the spatial distribution of Double-Strand Breaks (DSB) of the DNA (damage pattern), within a higher order chromatin structure. Single DSB are referred to as isolated DSB (iDSB) and two or more DSB in close proximity (within 540 nm) are called complex DSB (cDSB). In order to predict the cell-survival, the GLOBLE-Model considers different iDSB repair-pathways and their availability. One central assumption of the LEM is that the same damage patterns imply same effects, regardless of the radiation quality. In order to predict the damage pattern the microscopic local dose distribution of ions, described by the amorphous track structure, is evaluated. The cell survival after ion irradiation is predicted from a comparison with corresponding damage patterns after photon irradiation. The cell-survival curves after high dose photon irradiation cannot be predicted from the Linear Quadratic (LQ) Model due to their transition towards a linear dose dependence. This work uses the GLOBLE-Model to introduce a novel mechanistic approach, which allows the threshold dose to be predicted for the transition from a linear quadratic dose dependence, of survival curves at low doses, to a linear dose dependence at high doses. Furthermore, a method is presented, which allows LEM to predict the survival of synchronous cells after ion irradiation based on the cell survival after photon

  20. Poly(ADP-ribosyl)ation links the chromatin remodeler SMARCA5/SNF2H to RNF168-dependent DNA damage signaling

    NARCIS (Netherlands)

    G. Smeenk (Godelieve); W.W. Wiegant (Wouter); J.A. Marteijn (Jurgen); M.S. Luijsterburg (Martijn); N. Sroczynski (Nicholas); T. Costelloe (Thomas); R. Romeijn (Ron); A. Pastink (Albert); N. Mailand (Niels); W. Vermeulen (Wim); H. van Attikum (Haico)

    2013-01-01

    textabstractIonizing radiation (IR)-induced DNA double-strand breaks (DSBs) arising in native chromatin elicit an RNF8/RNF168-dependent ubiquitylation response, which triggers the recruitment of various repair factors. Precisely how this response is regulated in the context of chromatin remains

  1. Proton pump inhibitors suppress iNOS-dependent DNA damage in Barrett's esophagus by increasing Mn-SOD expression

    Energy Technology Data Exchange (ETDEWEB)

    Thanan, Raynoo [Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka, Mie 513-8670 (Japan); Department of Environmental and Molecular Medicine, Mie University Graduate School of Medicine, Tsu, Mie 514-8507 (Japan); Ma, Ning [Faculty of Health Science, Suzuka University of Medical Science, Suzuka, Mie 513-0293 (Japan); Iijima, Katsunori; Abe, Yasuhiko; Koike, Tomoyuki; Shimosegawa, Tooru [Division of Gastroenterology, Tohoku University Hospital, Sendai, Miyaki 980-8574 (Japan); Pinlaor, Somchai [Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002 (Thailand); Hiraku, Yusuke; Oikawa, Shinji; Murata, Mariko [Department of Environmental and Molecular Medicine, Mie University Graduate School of Medicine, Tsu, Mie 514-8507 (Japan); Kawanishi, Shosuke, E-mail: kawanisi@suzuka-u.ac.jp [Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka, Mie 513-8670 (Japan)

    2012-05-04

    Highlights: Black-Right-Pointing-Pointer Inflammation by Barrett's esophagus (BE) is a risk factor of its adenocarcinoma (BEA). Black-Right-Pointing-Pointer 8-Nitroguanine and 8-oxodG are inflammation-related DNA lesions. Black-Right-Pointing-Pointer DNA lesions and iNOS expression were higher in the order, BEA > BE > normal tissues. Black-Right-Pointing-Pointer Proton pump inhibitors suppress DNA damage by increasing Mn-SOD via Nrf2 activation. Black-Right-Pointing-Pointer DNA lesions can be useful biomarkers to predict risk of BEA in BE patients. -- Abstract: Barrett's esophagus (BE), an inflammatory disease, is a risk factor for Barrett's esophageal adenocarcinoma (BEA). Treatment of BE patients with proton pump inhibitors (PPIs) is expected to reduce the risk of BEA. We performed an immunohistochemical study to examine the formation of nitrative and oxidative DNA lesions, 8-nitroguanine and 8-oxo-7,8-dihydro-2 Prime -deoxygaunosine (8-oxodG), in normal esophageal, BE with pre- and post-treatment by PPIs and BEA tissues. We also observed the expression of an oxidant-generating enzyme (iNOS) and its transcription factor NF-{kappa}B, an antioxidant enzyme (Mn-SOD), its transcription factor (Nrf2) and an Nrf2 inhibitor (Keap1). The immunoreactivity of DNA lesions was significantly higher in the order of BEA > BE > normal tissues. iNOS expression was significantly higher in the order of BEA > BE > normal tissues, while Mn-SOD expression was significantly lower in the order of BEA < BE < normal tissues. Interestingly, Mn-SOD expression and the nuclear localization of Nrf2 were significantly increased, and the formation of DNA lesions was significantly decreased in BE tissues after PPIs treatment for 3-6 months. Keap1 and iNOS expression was not significantly changed by the PPIs treatment in BE tissues. These results indicate that 8-nitroguanine and 8-oxodG play a role in BE-derived BEA. Additionally, PPIs treatment may trigger the activation and

  2. Estimates of time-dependent fatigue behavior of Type 316 stainless steel subject to irradiation damage in fast breeder and fusion power reactor systems

    International Nuclear Information System (INIS)

    Brinkman, C.R.; Liu, K.C.; Grossbeck, M.L.

    1978-01-01

    Cyclic lives obtained from strain-controlled fatigue tests at 593 0 C of specimens irradiated in the experimental breeder reactor II (EBR-II) to a fluence of 1 to 2.63*10 26 neutrons (n)/m 2 (E>0.1 MeV) were compared with predictions based on the method of strain-range partitioning. It was demonstrated that, when appropriate tensile and creep-rupture ductilities were employed, reasonably good estimates of the influence of hold periods and irradiation damage on the fully reversed fatigue life of Type 316 stainless steel could be made. After applicability of this method was demonstrated, ductility values for 20 percent cold-worked Type 316 stainless steel specimens irradiated in a mixed-spectrum fission reactor were used to estimate fusion reactor first-wall lifetime. The ductility values used were from irradiations that simulate the environment of the first wall of a fusion reactor. Neutron wall loadings ranging from 2 to 5 MW/m 2 were used. 27 refs

  3. Detection of Ca2+-dependent acid phosphatase activity identifies neuronal integrity in damaged rat central nervous system after application of bacterial melanin

    Directory of Open Access Journals (Sweden)

    Tigran R Petrosyan

    2016-01-01

    Full Text Available The study aims to confirm the neuroregenerative effects of bacterial melanin (BM on central nervous system injury using a special staining method based on the detection of Ca2+-dependent acid phosphatase activity. Twenty-four rats were randomly assigned to undergo either unilateral destruction of sensorimotor cortex (group I; n = 12 or unilateral rubrospinal tract transection at the cervical level (C3–4 (group II; n = 12. In each group, six rats were randomly selected after surgery to undergo intramuscular injection of BM solution (BM subgroup and the remaining six rats were intramuscularly injected with saline (saline subgroup. Neurological testing confirmed that BM accelerated the recovery of motor function in rats from both BM and saline subgroups. Two months after surgery, Ca2+-dependent acid phosphatase activity detection in combination with Chilingarian's calcium adenoside triphosphate method revealed that BM stimulated the sprouting of fibers and dilated the capillaries in the brain and spinal cord. These results suggest that BM can promote the recovery of motor function of rats with central nervous system injury; and detection of Ca2+-dependent acid phosphatase activity is a fast and easy method used to study the regeneration-promoting effects of BM on the injured central nervous system.

  4. Specific dose-dependent damage of Lieberkuehn crypts promoted by large doses of type 2 ribosome-inactivating protein nigrin b intravenous injection to mice

    International Nuclear Information System (INIS)

    Gayoso, M.J.; Munoz, R.; Arias, Y.; Villar, R.; Rojo, M.A.; Jimenez, P.; Ferreras, J.M.; Aranguez, I.; Girbes, T.

    2005-01-01

    Nigrin b is a non-toxic type 2 ribosome-inactivating protein as active as ricin at ribosomal level but 10 5 and 5 x 10 3 times less toxic for animal cell cultures and mice, respectively, than ricin. The purpose of the present study was to analyze the effects of intravenous injection of large amounts of nigrin b to the mouse. Injection through the tail vein of 16 mg/kg body weight killed all mice studied before 2 days. Analysis of several major tissues by light microscopy did not reveal gross nigrin b-promoted changes, except in the intestines which appeared highly damaged. As a consequence of the injury, the villi and crypt structures of the small intestine disappeared, leading to profuse bleeding and death. In contrast, intravenous injection of 5 mg/kg body weight was not lethal to mice but did trigger reversible toxic effects. In both cases, lethal and sub-lethal doses, the target of nigrin b appeared to be the highly proliferating stem cells of the intestinal crypts, which had undergone apoptotic changes. In contrast to nigrin b, the injection of 3 μg/kg of ricin kills all mice in 5 days but does not trigger apoptosis in the crypts. Therefore, the effect seen with sub-lethal nigrin b concentrations seems to be specific. Nigrin b killed COLO 320 human colon adenocarcinoma cells with an IC 50 of 3.1 x 10 -8 M and the effect was parallel to the extent of DNA fragmentation of these cells. Accordingly, despite the low general toxicity exerted by nigrin b as compared with ricin, intravenous injection of large amounts of nigrin b is able to kill mouse intestinal stem cells without threatening the lives of the animals, thereby opening a door for its use for the targeting of intestinal stem cells

  5. Quercetin alters the DNA damage response in human hematopoietic stem and progenitor cells via TopoII- and PI3K-dependent mechanisms synergizing in leukemogenic rearrangements.

    Science.gov (United States)

    Biechonski, Shahar; Gourevich, Dana; Rall, Melanie; Aqaqe, Nasma; Yassin, Muhammad; Zipin-Roitman, Adi; Trakhtenbrot, Luba; Olender, Leonid; Raz, Yael; Jaffa, Ariel J; Grisaru, Dan; Wiesmuller, Lisa; Elad, David; Milyavsky, Michael

    2017-02-15

    Quercetin (Que) is an abundant flavonoid in the human diet and high-concentration food supplement with reported pro- and anti-carcinogenic activities. Topoisomerase II (TopoII) inhibition and subsequent DNA damage induction by Que was implicated in the mixed lineage leukemia gene (MLL) rearrangements that can induce infant and adult leukemias. This notion raised concerns regarding possible genotoxicities of Que in hematopoietic stem and progenitor cells (HSPCs). However, molecular targets mediating Que effects on DNA repair relevant to MLL translocations have not been defined. In this study we describe novel and potentially genotoxic Que activities in suppressing non-homologous end joining and homologous recombination pathways downstream of MLL cleavage. Using pharmacological dissection of DNA-PK, ATM and PI3K signalling we defined PI3K inhibition by Que with a concomitant decrease in the abundance of key DNA repair genes to be responsible for DNA repair inhibition. Evidence for the downstream TopoII-independent mutagenic potential of Que was obtained by documenting further increased frequencies of MLL rearrangements in human HSPCs concomitantly treated with Etoposide and Que versus single treatments. Importantly, by engaging a tissue engineered placental barrier, we have established the extent of Que transplacental transfer and hence provided the evidence for Que reaching fetal HSPCs. Thus, Que exhibits genotoxic effects in human HSPCs via different mechanisms when applied continuously and at high concentrations. In light of the demonstrated Que transfer to the fetal compartment our findings are key to understanding the mechanisms underlying infant leukemia and provide molecular markers for the development of safety values. © 2016 UICC.

  6. Estimates of time-dependent fatigue behavior of type 316 stainless steel subject to irradiation damage in fast breeder and fusion power reactor systems

    International Nuclear Information System (INIS)

    Brinkman, C.R.; Liu, K.C.; Grossbeck, M.L.

    1979-01-01

    Cyclic lives obtained from strain-controlled fatigue tests at 593 0 C of specimens irraidated in the experimental breeder reactor II (EBR-II) to a fluence of 1 to 2.63 x 10 26 neutrons (n)/m 2 E > 0.1 MeV) were compared with predictions based on the method of strain-range partitioning. It was demonstrated that, when appropriate tensile and creep-rupture ductilities were employed, reasonably good estimates of the influence of hold periods and irradiation damage on the fully reversed fatigue life of Type 316 stainless steel could be made. After applicability of this method was demonstrated, ductility values for 20% cold-worked Type 316 stainless steel specimens irradiated in a mixed-spectrum fission reactor were used to estimate fusion reactor first-wall lifetime. The ductility values used were from irradations that simulate the environment of the first wall of a fusion reactor. Neutron wall loadins ranging from 2 to 5 MW/m 2 were used. Results, although conjectural because of the many assumptions, tended to show that 20% cold-worked Type 316 stainless steel could be used as a first-wall material meeting a 7.5 go 8.5 MW-year/m 2 lifetime goal provided the neutron wall loading does not exceed more than about 2 MW/m 2 . These results were obtained for an air environment, ant it is expected that the actual vacuum environment will extend lifetime beyond 10 MW-year/m 2

  7. Radiation damage

    CERN Document Server

    Heijne, Erik H M; CERN. Geneva

    1998-01-01

    a) Radiation damage in organic materials. This series of lectures will give an overview of radiation effects on materials and components frequently used in accelerator engineering and experiments. Basic degradation phenomena will be presented for organic materials with comprehensive damage threshold doses for commonly used rubbers, thermoplastics, thermosets and composite materials. Some indications will be given for glass, scintillators and optical fibres. b) Radiation effects in semiconductor materials and devices. The major part of the time will be devoted to treat radiation effects in semiconductor sensors and the associated electronics, in particular displacement damage, interface and single event phenomena. Evaluation methods and practical aspects will be shown. Strategies will be developed for the survival of the materials under the expected environmental conditions of the LHC machine and detectors. I will describe profound revolution in our understanding of black holes and their relation to quantum me...

  8. Tort Damages

    NARCIS (Netherlands)

    L.T. Visscher (Louis)

    2008-01-01

    textabstractAbstract: In this Chapter, I provide an overview of Law and Economics literature regarding tort damages. Where necessary, attention is also spent to rules of tort liability. Both types of rules provide behavioral incentives to both injurers and victims, with respect to their level of

  9. Fas-Induced Apoptosis of Renal Cell Carcinoma is Mediated by Apoptosis Signal-Regulating Kinase 1 via Mitochondrial Damage-Dependent Caspase-8 Activation

    Directory of Open Access Journals (Sweden)

    Mohamed Hassan

    2009-01-01

    Full Text Available Renal cell carcinoma (RCC is a prototype of a chemo refractory tumour. It remains the most lethal of the common urologic cancers and is highly resistant to conventional therapy. Here, we confirmed the efficiency of anti-Fas monoclonal antibody (CH11 as alternative therapeutic approach for the treatment of RCC and investigated the molecular mechanism(s, whereby CH11 induces apoptosis of RCC cells. The present study shows an essential role for apoptosis signal-regulating kinase 1 (ASK1, together with both c-jun-N-terminal kinase (JNK and p38 pathways, and caspase-8 in this process. Furthermore, CH11-dependent induction of the ASK1–JNK/p38 pathways was found to activate the transcription factors AP-1 and ATF-2, and FADD-caspase-8-Bid signalling, resulting in the translocation of both Bax and Bak proteins, and subsequently mitochondrial dysregulation that is characterized by the loss of mitochondrial membrane potential (ΔΨm, cytochrome c release and cleavage of caspase-9, caspase-3 and PARP. Thus, the described molecular mechanisms of CH11-induced apoptosis suggest the reliability of Fas activation as an alternative therapeutic approach for the treatment of patients with advanced renal cell carcinoma.

  10. The dependence of natural regeneration of forest trees on upper soil conditions and acidity at damaged sites in the Black Forest, Germany

    International Nuclear Information System (INIS)

    Littek, T.

    1993-06-01

    It was the goal of this study to investigate the influence of different upper soil conditions on the germination and establishment, as well as the growth, of young plants of various tree species. For this purpose, four test plots in the region of the Black Forest were laid out, in which, by various means of site preparation and fertilization, the upper soils were changed. Natural seeding of common spruce, European silver-fir, beech, sycamore maple, European mountainash, and grey alder was simulated by means of controlled sowing. For comparison, a greenhouse experiment was carried out, examining the germination and development of the same tree species in various soil substrata, using different fertilizers, and under the influence of artificial acid rain. The most important results - with a high level of variation depending on the tree species examined - can be summarized as follows: Based on the results of field and greenhouse experiments, as well as on the investigations of other authors, it can be concluded that natural regeneration of forest stands is considerably impeded under conditions of increasing soil acidity and by high acid depositions. This is seen directly as the result of unfavorable chemical conditions in the upper soil, as well as indirectly due to deteriorating competitiveness against other vegetation. Site preparation and lime or dolomite fertilization can be important measures in the practice of forestry, to encourage natural regeneration in highly acidic sites with an unfavourable humus layer and a high presence of competing vegetation. (orig./UWA). 2 figs., 85 tabs., 269 refs [de

  11. Radiation-induced damage of membranes

    International Nuclear Information System (INIS)

    Yonei, Shuji

    1977-01-01

    An outline of membranous structure was stated, and radiation-induced damage of membranes were surveyed. By irradiation, permeability of membranes, especially passive transportation mechanism, was damaged, and glycoprotein in the surface layers of cells and the surface layer structures were changed. The intramembranous damage was induced by decrease of electrophoresis of nuclear mambranes and a quantitative change of cytochrome P450 of microsomal membranes of the liver, and peroxidation of membranous lipid and SH substitute damage of membranous protein were mentioned as the mechanism of membranous damage. Recovery of membranous damage depends on radiation dose and temperature, and membranous damage participates largely in proliferation death. (tsunoda, M.)

  12. Reinnervation of the diaphragm by the inferior laryngeal nerve to the phrenic nerve in ventilator-dependent tetraplegic patients with C3-5 damage.

    Science.gov (United States)

    Verin, Eric; Morelot-Panzini, Capucine; Gonzalez-Bermejo, Jesus; Veber, Benoit; Perrouin Verbe, Brigitte; Soudrie, Brigitte; Leroi, Anne Marie; Marie, Jean Paul; Similowski, Thomas

    2017-10-01

    The aim of this study was to evaluate the feasibility of unilateral diaphragmatic reinnervation in humans by the inferior laryngeal nerve. This pilot study included chronically ventilated tetraplegic patients with destruction of phrenic nerve motoneurons. Five patients were included. They all had a high level of tetraplegia, with phrenic nerve motor neuron destruction. They were highly dependent on ventilation, without any possibility of weaning. They did not have other chronic pathologies, especially laryngeal disease. They all had diaphragmatic explorations to diagnose the destruction of the motoneurons of the phrenic nerves and nasoendoscopy to be sure that they did not have laryngeal or pharyngeal disease. Then, surgical anastomosis of the right phrenic nerve was performed with the inferior laryngeal nerve, by a cervical approach. A laryngeal reinnervation was performed at the same time, using the ansa hypoglossi. One patient was excluded because of a functional phrenic nerve and one patient died 6 months after the surgery of a cardiac arrest. The remaining three patients were evaluated after the anastomosis every 6 months. They did not present any swallowing or vocal alterations. In these three patients, the diaphragmatic explorations showed that there was a recovery of the diaphragmatic electromyogram of the right and left hemidiaphragms after 1 year. Two patients had surgical diaphragmatic explorations for diaphragmatic pacing 18-24 months after the reinnervation with excellent results. At 36 months, none of the patients could restore their automatic ventilation. In conclusion, this study demonstrated that diaphragmatic reinnervation by the inferior laryngeal nerve is effective, without any vocal or swallowing complications.

  13. Circadian transitions in radiation dose-dependent augmentation of mRNA levels for DNA damage-induced genes elicited by accurate real-time RT-PCR quantification

    International Nuclear Information System (INIS)

    Ishihara, Hiroshi; Tanaka, Izumi; Yakumaru, Haruko

    2010-01-01

    Molecular mechanisms of intracellular response after DNA-damage by exposure to ionizing radiation have been studied. In the case of cells isolated from living body of human and experimental animals, alteration of the responsiveness by physiological oscillation such as circadian rhythm must be considered. To examine the circadian variation in the response of p53-responsible genes p21, mdm2, bax, and puma, we established a method to quantitate their mRNA levels with high reproducibility and accuracy based on real-time reverse transcription polymerase chain reaction (RT-PCR) and compared the levels of responsiveness in mouse hemocytes after diurnal irradiation to that after nocturnal irradiation. Augmentations of p21 and mdm2 mRNA levels with growth-arrest and of puma mRNA before apoptosis were confirmed by time-course experiment in RAW264.7, and dose-dependent increases in the peak levels of all the RNA were shown. Similarly, the relative RNA levels of p21, mdm2, bax, and puma per glyceraldehyde-3-phosphate dehydrogenase (GAPDH) also increased dose-dependently in peripheral blood and bone marrow cells isolated from whole-body-irradiated mice. Induction levels of all messages reduced by half after nighttime irradiation as compared with daytime irradiation in blood cells. In marrow cells, nighttime irradiation enhanced the p21 and mdm2 mRNA levels than daytime irradiation. No significant difference in bax or puma mRNA levels was observed between nighttime and daytime irradiation in marrow cells. This suggests that early-stage cellular responsiveness in DNA damage-induced genes is modulated between diurnal and nocturnal irradiation. (author)

  14. Inhibitory effect of Clitoria ternatea flower petal extract on fructose-induced protein glycation and oxidation-dependent damages to albumin in vitro.

    Science.gov (United States)

    Chayaratanasin, Poramin; Barbieri, Manuel Alejandro; Suanpairintr, Nipattra; Adisakwattana, Sirichai

    2015-02-18

    The accumulation of advanced glycation end products (AGEs) in body tissue has been implicated in the progression of age-related diseases. Inhibition of AGE formation is the imperative approach for alleviating diabetic complications. Clitoria ternatea extract (CTE) has been demonstrated to possess anti-diabetic activity. However, there is no scientific evidence supporting its anti-glycation activity. The objective of this study was to determine the inhibitory effect of CTE on fructose-induced formation of AGEs and protein oxidation. Antioxidant activity of CTE was also assessed by various methods. The aqueous extract of CTE (0.25-1.00 mg/ml) was measured for the content of total phenolic compounds, flavonoid, and anthocyanin by Folin-Ciocalteu assay, AlCl3 colorimetric method, and pH differential method, respectively. The various concentrations of CTE were incubated with BSA and fructose at 37°C for 28 days. The formation of fluorescent AGEs, the level of fructosamine, protein carbonyl content, and thiol group were measured. The in vitro antioxidant activity was measured by the 1,1-diphenyl 2-picrylhydrazyl (DPPH) scavenging activity, trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP), hydroxyl radical scavenging activity (HRSA), superoxide radical scavenging activity (SRSA), and ferrous ion chelating power (FICP). The results demonstrated that the content of total phenolics, flavonoids and total anthocyanins in CTE was 53 ± 0.34 mg gallic acid equivalents/g dried extract, 11.2 ± 0.33 mg catechin equivalents/g dried extract, and 1.46 ± 0.04 mg cyanidin-3-glucoside equivalents/g dried extract, respectively. Moreover, CTE (0.25-1.00 mg/ml) significantly inhibited the formation of AGEs in a concentration-dependent manner. CTE also markedly reduced the levels of fructosamine and the oxidation of protein by decreasing protein carbonyl content and preventing free thiol depletion. In the DPPH radical scavenging

  15. Determination of post-shakedown quantities of a pipe bend via the simplified theory of plastic zones compared with load history dependent incremental analysis

    Science.gov (United States)

    Vollrath, Bastian; Hübel, Hartwig

    2018-01-01

    The Simplified Theory of Plastic Zones (STPZ) may be used to determine post-shakedown quantities such as strain ranges and accumulated strains at plastic or elastic shakedown. The principles of the method are summarized. Its practical applicability is shown by the example of a pipe bend subjected to constant internal pressure along with cyclic in-plane bending or/and cyclic radial temperature gradient. The results are compared with incremental analyses performed step-by-step throughout the entire load history until the state of plastic shakedown is achieved.

  16. Damage-induced tensile instability

    International Nuclear Information System (INIS)

    Hult, J.

    1975-01-01

    The paper presents a unified description of ductile and brittle rupture phenomena in structural components under tensile loading with particular emphasis on creep rupture. Two structural elements are analyzed in detail: 1) the uniform tensile bar subject to a Heaviside history of tensile force and superimposed such loadings, i.e. staircase histories, and 2) the thinwalled spherical pressure vessel subject to a Heaviside history of internal pressure. For both these structures the conditions for instantaneous as well as delayed rupture are analysed. It is shown that a state of mechanical instability will be reached at a certain load or after a certain time. The cases of purely ductile rupture and purely brittle fracture are identified as two limiting cases of this general instability phenomenon. The Kachanov-Rabotnov damage law implies that a structural component will fail in tension only when it has reached a state of complete damage, i.e. zero load carrying capacity. The extended law predicts failure at an earlier stage of the deterioration process and is therefore more compatible with experimental observation. Further experimental support is offered by predictions for staircase loading histories, both step-up and step-down type. The presented damage theory here predicts strain histories which are in closer agreement with test data than predictions based on other phenomenological theories

  17. Radiation damage of uranium

    International Nuclear Information System (INIS)

    Lazarevic, Dj.

    1966-11-01

    Study of radiation damage covered the following: Kinetics of electric resistance of uranium and uranium alloy with 1% of molybdenum dependent on the second phase and burnup rate; Study of gas precipitation and diffusion of bubbles by transmission electron microscopy; Numerical analysis of the influence of defects distribution and concentration on the rare gas precipitation in uranium; study of thermal sedimentation of uranium alloy with molybdenum; diffusion of rare gas in metal by gas chromatography method

  18. Bohmian histories and decoherent histories

    International Nuclear Information System (INIS)

    Hartle, James B.

    2004-01-01

    The predictions of the Bohmian and the decoherent (or consistent) histories formulations of the quantum mechanics of a closed system are compared for histories--sequences of alternatives at a series of times. For certain kinds of histories, Bohmian mechanics and decoherent histories may both be formulated in the same mathematical framework within which they can be compared. In that framework, Bohmian mechanics and decoherent histories represent a given history by different operators. Their predictions for the probabilities of histories of a closed system therefore generally differ. However, in an idealized model of measurement, the predictions of Bohmian mechanics and decoherent histories coincide for the probabilities of records of measurement outcomes. The formulations are thus difficult to distinguish experimentally. They may differ in their accounts of the past history of the Universe in quantum cosmology

  19. Lifetime history of traumatic events in a young adult Mexican American sample: Relation to substance dependence, affective disorder, acculturation stress, and PTSD.

    Science.gov (United States)

    Ehlers, Cindy L; Kim, Corinne; Gilder, David A; Stouffer, Gina M; Caetano, Raul; Yehuda, Rachel

    2016-12-01

    Mexican Americans comprise one of the most rapidly growing populations in the United States, and within this population, trauma and post-traumatic stress disorder (PTSD) are associated with physical and mental health problems. Therefore, efforts to delineate factors that may uniquely contribute to increased likelihood of trauma, PTSD, and substance use disorders over the lifetime in Mexican Americans are important to address health disparities and to develop treatment and prevention programs. Six hundred fourteen young adults (age 18-30 yrs) of Mexican American heritage, largely second generation, were recruited from the community and assessed with the Semi-Structured Assessment for the Genetics of Alcoholism and an acculturation stress scale. More males (51.2%) reported experiencing traumas than females (41.1%), however, a larger proportion of females received a PTSD diagnosis (15%) than males (8%). Alcohol dependence and affective disorders, but not anxiety disorders, antisocial disorders, nicotine, marijuana, or stimulant dependence, were significantly comorbid with PTSD. Endorsing higher levels of acculturation stress was also significantly associated with both trauma exposure and a diagnosis of PTSD. Logistic regression revealed that female gender, having an affective disorder, alcohol dependence, higher levels of acculturation stress, and lower levels of education were all predictors of PTSD status. Additionally, alcohol dependence generally occurred after the PTSD diagnosis in early adulthood in this high-risk population. These studies suggest that treatment and prevention efforts should particularly focus on young adult second generation Mexican American women with higher levels of acculturation stress, who may be at higher risk for PTSD, affective disorder, and alcohol dependence following trauma exposure. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Lifetime history of traumatic events in a young adult Mexican American sample: relation to substance dependence, affective disorder, acculturation stress, and PTSD

    Science.gov (United States)

    Ehlers, Cindy L.; Kim, Corinne; Gilder, David A.; Stouffer, Gina M.; Caetano, Raul; Yehuda, Rachel

    2016-01-01

    Mexican Americans comprise one of the most rapidly growing populations in the United States, and within this population, trauma and post-traumatic stress disorder (PTSD) are associated with physical and mental health problems. Therefore, efforts to delineate factors that may uniquely contribute to increased likelihood of trauma, PTSD, and substance use disorders over the lifetime in Mexican Americans are important to address health disparities and to develop treatment and prevention programs. Six hundred fourteen young adults (age 18–30 yrs) of Mexican American heritage, largely second generation, were recruited from the community and assessed with the Semi-Structured Assessment for the Genetics of Alcoholism and an acculturation stress scale. More males (51.2%) reported experiencing traumas than females (41.1%), however, a larger proportion of females received a PTSD diagnosis (15%) than males (8%). Alcohol dependence and affective disorders, but not anxiety disorders, antisocial disorders, nicotine, marijuana, or stimulant dependence, were significantly comorbid with PTSD. Endorsing higher levels of acculturation stress was also significantly associated with both trauma exposure and a diagnosis of PTSD. Logistic regression revealed that female gender, having an affective disorder, alcohol dependence, higher levels of acculturation stress, and lower levels of education were all predictors of PTSD status. Additionally, alcohol dependence generally occurred after the PTSD diagnosis in early adulthood in this high-risk population. These studies suggest that treatment and prevention efforts should particularly focus on young adult second generation Mexican American women with higher levels of acculturation stress, who may be at higher risk for PTSD, affective disorder, and alcohol dependence following trauma exposure. PMID:27569652

  1. History Matters

    Institute of Scientific and Technical Information of China (English)

    2017-01-01

    In 2002, she began working as alecturer at Minzu University of China.Now, she teaches English, historicalliterature, ancient Chinese history,historical theory and method, ancientsocial history of China, ancient palacepolitical history of China and the historyof the Sui and Tang dynasties and thePeriod of Five Dynasties.

  2. Damage characterization and modeling of a 7075-T651 aluminum plate

    International Nuclear Information System (INIS)

    Jordon, J.B.; Horstemeyer, M.F.; Solanki, K.; Bernard, J.D.; Berry, J.T.; Williams, T.N.

    2009-01-01

    In this paper, the damage-induced anisotropy arising from material microstructure heterogeneities at two different length scales was characterized and modeled for a wrought aluminum alloy. Experiments were performed on a 7075-T651 aluminum alloy plate using sub-standard tensile specimens in three different orientations with respect to the rolling direction. Scanning electron microscopy was employed to characterize the stereology of the final damage state in terms of cracked and or debonded particles. A physically motivated internal state variable continuum model was used to predict fracture by incorporating material microstructural features. The continuum model showed good comparisons to the experimental data by capturing the damage-induced anisotropic material response. Estimations of the mechanical stress-strain response, material damage histories, and final failure were numerically calculated and experimentally validated thus demonstrating that the final failure state was strongly dependent on the constituent particle morphology.

  3. Irradiation damage

    Energy Technology Data Exchange (ETDEWEB)

    Howe, L.M

    2000-07-01

    There is considerable interest in irradiation effects in intermetallic compounds from both the applied and fundamental aspects. Initially, this interest was associated mainly with nuclear reactor programs but it now extends to the fields of ion-beam modification of metals, behaviour of amorphous materials, ion-beam processing of electronic materials, and ion-beam simulations of various kinds. The field of irradiation damage in intermetallic compounds is rapidly expanding, and no attempt will be made in this chapter to cover all of the various aspects. Instead, attention will be focused on some specific areas and, hopefully, through these, some insight will be given into the physical processes involved, the present state of our knowledge, and the challenge of obtaining more comprehensive understanding in the future. The specific areas that will be covered are: point defects in intermetallic compounds; irradiation-enhanced ordering and irradiation-induced disordering of ordered alloys; irradiation-induced amorphization.

  4. Irradiation damage

    International Nuclear Information System (INIS)

    Howe, L.M.

    2000-01-01

    There is considerable interest in irradiation effects in intermetallic compounds from both the applied and fundamental aspects. Initially, this interest was associated mainly with nuclear reactor programs but it now extends to the fields of ion-beam modification of metals, behaviour of amorphous materials, ion-beam processing of electronic materials, and ion-beam simulations of various kinds. The field of irradiation damage in intermetallic compounds is rapidly expanding, and no attempt will be made in this chapter to cover all of the various aspects. Instead, attention will be focused on some specific areas and, hopefully, through these, some insight will be given into the physical processes involved, the present state of our knowledge, and the challenge of obtaining more comprehensive understanding in the future. The specific areas that will be covered are: point defects in intermetallic compounds; irradiation-enhanced ordering and irradiation-induced disordering of ordered alloys; irradiation-induced amorphization

  5. Cumulative damage fatigue tests on nuclear reactor Zircaloy-2 fuel tubes at room temperature and 3000C

    International Nuclear Information System (INIS)

    Pandarinathan, P.R.; Vasudevan, P.

    1980-01-01

    Cumulative damage fatigue tests were conducted on the Zircaloy-2 fuel tubes at room temperature and 300 0 C on the modified Moore type, four-point-loaded, deflection-controlled, rotating bending fatigue testing machine. The cumulative cycle ratio at fracture for the Zircaloy-2 fuel tubes was found to depend on the sequence of loading, stress history, number of cycles of application of the pre-stress and the test temperature. A Hi-Lo type fatigue loading was found to be very much damaging at room temperature and this feature was not observed in the tests at 300 0 C. Results indicate significant differences in damage interaction and damage propagation under cumulative damage tests at room temperature and at 300 0 C. Block-loading fatigue tests are suggested as the best method to determine the life-time of Zircaloy-2 fuel tubes under random fatigue loading during their service in the reactor. (orig.)

  6. Steady State Shift Damage Localization

    DEFF Research Database (Denmark)

    Sekjær, Claus; Bull, Thomas; Markvart, Morten Kusk

    2017-01-01

    The steady state shift damage localization (S3DL) method localizes structural deterioration, manifested as either a mass or stiffness perturbation, by interrogating the damage-induced change in the steady state vibration response with damage patterns cast from a theoretical model. Damage is, thus...... the required accuracy when examining complex structures, an extensive amount of degrees of freedom (DOF) must often be utilized. Since the interrogation matrix for each damage pattern depends on the size of the system matrices constituting the FE-model, the computational time quickly becomes of first......-order importance. The present paper investigates two sub-structuring approaches, in which the idea is to employ Craig-Bampton super-elements to reduce the amount of interrogation distributions while still providing an acceptable localization resolution. The first approach operates on a strict super-element level...

  7. Corticotropin-releasing Factor in the Rat Dorsal Raphe Nucleus Promotes Different Forms of Behavioral Flexibility Depending on Social Stress History.

    Science.gov (United States)

    Snyder, Kevin P; Hill-Smith, Tiffany E; Lucki, Irwin; Valentino, Rita J

    2015-10-01

    The stress-related neuropeptide, corticotropin-releasing factor (CRF) regulates the dorsal raphe nucleus-serotonin (DRN-5-HT) system during stress and this may underlie affective and cognitive dysfunctions that characterize stress-related psychiatric disorders. CRF acts on both CRF1 and CRF2 receptor subtypes in the DRN that exert opposing inhibitory and excitatory effects on DRN-5-HT neuronal activity and 5-HT forebrain release, respectively. The current study first assessed the cognitive effects of intra-DRN microinfusion of CRF or the selective CRF2 agonist, urocortin II in stress-naive rats on performance of an operant strategy set-shifting task that is mediated by the medial prefrontal cortex (mPFC). CRF (30 ng) facilitated strategy set-shifting performance, whereas higher doses of CRF and urocortin II that would interact with CRF2 were without effect, consistent with a CRF1-mediated action. This dose decreased 5-HT extracellular levels in the mPFC, further supporting a role for CRF1. The effects of CRF were then assessed in rats exposed to repeated social stress using the resident-intruder model. Repeated social stress shifted the CRF effect from facilitation of strategy set shifting to facilitation of reversal learning and this was most prominent in a subpopulation of rats that resist defeat. Notably, in this subpopulation of rats 5-HT neuronal responses to CRF have been demonstrated to shift from CRF1-mediated inhibition to CRF2-mediated excitation. Because 5-HT facilitates reversal learning, the present results suggest that stress-induced changes in the cellular effects of CRF in the DRN translate to changes in cognitive effects of CRF. Together, the results underscore the potential for stress history to shift cognitive processing through changes in CRF neurotransmission in the DRN and the association of this effect with coping strategy.

  8. A History of Online Gatekeeping

    OpenAIRE

    Zittrain, Jonathan

    2006-01-01

    The brief but intense history of American judicial and legislative confrontation with problems caused by the online world has demonstrated a certain wisdom: a reluctance to intervene in ways that dramatically alter online architectures; a solicitude for the collateral damage that interventions might wreak upon innocent activity; and, in the balance, a refusal to allow unambiguously damaging activities to remain unchecked if there is a way to curtail them. The ability to regulate lightly ...

  9. War in European history

    International Nuclear Information System (INIS)

    Howard, M.

    1981-01-01

    War history as a modern historic discipline is by far no longer a mere history of arms technique or a chronicle of battles. It deals with the change of warfare, shows how the wars of the various ages had determined society, and vice versay investigates the influence of social, economic, and -concerning mentality-historical changes on war. With this survey, which covers the period between the Middle Ages and the recent past, the author has presented a small masterpiece of the history of war. A book like this is particularly important and instructive in a time when all depends on the preventing of wars. (orig.) [de

  10. Damaged Skylab

    Science.gov (United States)

    1973-01-01

    The Saturn V vehicle, carrying the unmarned orbital workshop for the Skylab-1 mission, lifted off successfully and all systems performed normally. Sixty-three seconds into the flight, engineers in the operation support and control center saw an unexpected telemetry indication that signalled that damages occurred on one solar array and the micrometeoroid shield during the launch. The micrometeoroid shield, a thin protective cylinder surrounding the workshop protecting it from tiny space particles and the sun's scorching heat, ripped loose from its position around the workshop. This caused the loss of one solar wing and jammed the other. Still unoccupied, the Skylab was stricken with the loss of the heat shield and sunlight beat mercilessly on the lab's sensitive skin. Internal temperatures soared, rendering the station uninhabitable, threatening foods, medicines, films, and experiments. This image, taken during a fly-around inspection by the Skylab-2 crew, shows a crippled Skylab in orbit. The crew found their home in space to be in serious shape; the heat shield gone, one solar wing gone, and the other jammed. The Marshall Space Flight Center (MSFC) developed, tested, rehearsed, and approved three repair options. These options included a parasol sunshade and a twin-pole sunshade to restore the temperature inside the workshop, and a set of metal cutting tools to free the jammed solar panel.

  11. Structural damage

    International Nuclear Information System (INIS)

    Gray, R.E.; Bruhn, R.W.

    1992-01-01

    Virtually all structures show some signs of distress due to deterioration of the building components, to changed loads, or to changed support conditions. Changed support conditions result from ground movements. In mining regions many cases of structural distress are attributed to mining without considering alternative causes. This is particularly true of coal mining since it occurs under extensive areas. Coal mining is estimated to have already undermined more than eight million acres and may eventually undermine 40 million acres in the United States. Other nonmetal and metal underground mines impact much smaller areas. Although it is sometimes difficult, even with careful study, to identify the actual cause of damage, persons responsible for underground coal mining should at least be aware of possible causes of building stress other than mine subsidence. This paper presents information on distress to structures and briefly reviews a number of causes of ground movements other than subsidence: Mass movements, dissolution, erosion, frost action, shrinking and swelling, yield into excavations and compressibility

  12. Entangled histories

    International Nuclear Information System (INIS)

    Cotler, Jordan; Wilczek, Frank

    2016-01-01

    We introduce quantum history states and their mathematical framework, thereby reinterpreting and extending the consistent histories approach to quantum theory. Through thought experiments, we demonstrate that our formalism allows us to analyze a quantum version of history in which we reconstruct the past by observations. In particular, we can pass from measurements to inferences about ‘what happened’ in a way that is sensible and free of paradox. Our framework allows for a richer understanding of the temporal structure of quantum theory, and we construct history states that embody peculiar, non-classical correlations in time. (paper)

  13. Radiation damage prediction system using damage function

    International Nuclear Information System (INIS)

    Tanaka, Yoshihisa; Mori, Seiji

    1979-01-01

    The irradiation damage analysis system using a damage function was investigated. This irradiation damage analysis system consists of the following three processes, the unfolding of a damage function, the calculation of the neutron flux spectrum of the object of damage analysis and the estimation of irradiation effect of the object of damage analysis. The damage function is calculated by applying the SAND-2 code. The ANISN and DOT3, 5 codes are used to calculate neutron flux. The neutron radiation and the allowable time of reactor operation can be estimated based on these calculations of the damage function and neutron flux. The flow diagram of the process of analyzing irradiation damage by a damage function and the flow diagram of SAND-2 code are presented, and the analytical code for estimating damage, which is determined with a damage function and a neutron spectrum, is explained. The application of the irradiation damage analysis system using a damage function was carried out to the core support structure of a fast breeder reactor for the damage estimation and the uncertainty evaluation. The fundamental analytical conditions and the analytical model for this work are presented, then the irradiation data for SUS304, the initial estimated values of a damage function, the error analysis for a damage function and the analytical results are explained concerning the computation of a damage function for 10% total elongation. Concerning the damage estimation of FBR core support structure, the standard and lower limiting values of damage, the permissible neutron flux and the allowable years of reactor operation are presented and were evaluated. (Nakai, Y.)

  14. TAS3 miR390-dependent loci in non-vascular land plants: towards a comprehensive reconstruction of the gene evolutionary history

    Directory of Open Access Journals (Sweden)

    Sergey Y. Morozov

    2018-04-01

    Full Text Available Trans-acting small interfering RNAs (ta-siRNAs are transcribed from protein non-coding genomic TAS loci and belong to a plant-specific class of endogenous small RNAs. These siRNAs have been found to regulate gene expression in most taxa including seed plants, gymnosperms, ferns and mosses. In this study, bioinformatic and experimental PCR-based approaches were used as tools to analyze TAS3 and TAS6 loci in transcriptomes and genomic DNAs from representatives of evolutionary distant non-vascular plant taxa such as Bryophyta, Marchantiophyta and Anthocerotophyta. We revealed previously undiscovered TAS3 loci in plant classes Sphagnopsida and Anthocerotopsida, as well as TAS6 loci in Bryophyta classes Tetraphidiopsida, Polytrichopsida, Andreaeopsida and Takakiopsida. These data further unveil the evolutionary pathway of the miR390-dependent TAS3 loci in land plants. We also identified charophyte alga sequences coding for SUPPRESSOR OF GENE SILENCING 3 (SGS3, which is required for generation of ta-siRNAs in plants, and hypothesized that the appearance of TAS3-related sequences could take place at a very early step in evolutionary transition from charophyte algae to an earliest common ancestor of land plants.

  15. TAS3 miR390-dependent loci in non-vascular land plants: towards a comprehensive reconstruction of the gene evolutionary history.

    Science.gov (United States)

    Morozov, Sergey Y; Milyutina, Irina A; Erokhina, Tatiana N; Ozerova, Liudmila V; Troitsky, Alexey V; Solovyev, Andrey G

    2018-01-01

    Trans-acting small interfering RNAs (ta-siRNAs) are transcribed from protein non-coding genomic TAS loci and belong to a plant-specific class of endogenous small RNAs. These siRNAs have been found to regulate gene expression in most taxa including seed plants, gymnosperms, ferns and mosses. In this study, bioinformatic and experimental PCR-based approaches were used as tools to analyze TAS3 and TAS6 loci in transcriptomes and genomic DNAs from representatives of evolutionary distant non-vascular plant taxa such as Bryophyta, Marchantiophyta and Anthocerotophyta. We revealed previously undiscovered TAS3 loci in plant classes Sphagnopsida and Anthocerotopsida, as well as TAS6 loci in Bryophyta classes Tetraphidiopsida, Polytrichopsida, Andreaeopsida and Takakiopsida. These data further unveil the evolutionary pathway of the miR390-dependent TAS3 loci in land plants. We also identified charophyte alga sequences coding for SUPPRESSOR OF GENE SILENCING 3 (SGS3), which is required for generation of ta-siRNAs in plants, and hypothesized that the appearance of TAS3-related sequences could take place at a very early step in evolutionary transition from charophyte algae to an earliest common ancestor of land plants.

  16. Intellectual History

    DEFF Research Database (Denmark)

    In the 5 Questions book series, this volume presents a range of leading scholars in Intellectual History and the History of Ideas through their answers to a brief questionnaire. Respondents include Michael Friedman, Jacques le Goff, Hans Ulrich Gumbrecht, Jonathan Israel, Phiip Pettit, John Pocock...

  17. Natural History of Dependency in the Elderly: A 24-Year Population-Based Study Using a Longitudinal Item Response Theory Model.

    Science.gov (United States)

    Edjolo, Arlette; Proust-Lima, Cécile; Delva, Fleur; Dartigues, Jean-François; Pérès, Karine

    2016-02-15

    We aimed to describe the hierarchical structure of Instrumental Activities of Daily Living (IADL) and basic Activities of Daily Living (ADL) and trajectories of dependency before death in an elderly population using item response theory methodology. Data were obtained from a population-based French cohort study, the Personnes Agées QUID (PAQUID) Study, of persons aged ≥65 years at baseline in 1988 who were recruited from 75 randomly selected areas in Gironde and Dordogne. We evaluated IADL and ADL data collected at home every 2-3 years over a 24-year period (1988-2012) for 3,238 deceased participants (43.9% men). We used a longitudinal item response theory model to investigate the item sequence of 11 IADL and ADL combined into a single scale and functional trajectories adjusted for education, sex, and age at death. The findings confirmed the earliest losses in IADL (shopping, transporting, finances) at the partial limitation level, and then an overlapping of concomitant IADL and ADL, with bathing and dressing being the earliest ADL losses, and finally total losses for toileting, continence, eating, and transferring. Functional trajectories were sex-specific, with a benefit of high education that persisted until death in men but was only transient in women. An in-depth understanding of this sequence provides an early warning of functional decline for better adaptation of medical and social care in the elderly. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Fatigue Damage in Wood

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Bo Uhre; Hoffmeyer, Preben

    1996-01-01

    An investigation of fatigue failure in wood subjected to load cycles in compression parallel to grain is presented. Fatigue failure is found to depend both on the total time under load and on the number of cycles.Recent accelerated fatigue research on wood is reviewed, and a discrepancy between...... to 10 Hz are used. The number of cycles to failure is found to be a poor measure of the fatigue performance of wood. Creep, maximum strain, stiffness and work are monitored throughout the fatigue tests. Accumulated creep is suggested identified with damage and a correlation between stiffness reduction...

  19. Assessment of gamma ray-induced DNA damage in Lasioderma serricorne using the comet assay

    International Nuclear Information System (INIS)

    Kameya, Hiromi; Miyanoshita, Akihiro; Imamura, Taro; Todoriki, Setsuko

    2012-01-01

    We attempted a DNA comet assay under alkaline conditions to verify the irradiation treatment of pests. Lasioderma serricorne (Fabricius) were chosen as test insects and irradiated with gamma rays from a 60 Co source at 1 kGy. We conducted the comet assay immediately after irradiation and over time for 7 day. Severe DNA fragmentation in L. serricorne cells was observed just after irradiation and the damage was repaired during the post-irradiation period in a time-dependent manner. The parameters of the comet image analysis were calculated, and the degree of DNA damage and repair were evaluated. Values for the Ratio (a percentage determined by fluorescence in the damaged area to overall luminance, including intact DNA and the damaged area of a comet image) of individual cells showed that no cells in the irradiated group were included in the Ratio<0.1 category, the lowest grade. This finding was observed consistently throughout the 7-day post-irradiation period. We suggest that the Ratio values of individual cells can be used as an index of irradiation history and conclude that the DNA comet assay under alkaline conditions, combined with comet image analysis, can be used to identify irradiation history. - Highlights: ► We investigated the DNA comet assay to verify the irradiation of pests. ► Ratio and Tail Moment were higher in irradiated groups than in the control group. ► The DNA comet assay can be used to identify irradiation history.

  20. Shaped input distributions for structural damage localization

    DEFF Research Database (Denmark)

    Ulriksen, Martin Dalgaard; Bernal, Dionisio; Damkilde, Lars

    2018-01-01

    localization method is cast that operates on the premise of shaping inputs—whose spatial distribution is fixed—by use of a model, such that these inputs, in one structural subdomain at a time, suppress certain steady-state vibration quantities (depending on the type of damage one seeks to interrogate for......). Accordingly, damage is localized when the vibration signature induced by the shaped inputs in the damaged state corresponds to that in the reference state, hereby implying that the approach does not point directly to damage. Instead, it operates with interrogation based on postulated damage patterns...

  1. Induction of Nrf2-dependent Antioxidation and Protection Against Carbon Tetrachloride-induced Liver Damage by Andrographis Herba (穿心蓮chuān xīn lián Ethanolic Extract

    Directory of Open Access Journals (Sweden)

    Haw-Wen Chen

    2012-07-01

    Full Text Available Andrographis paniculata is a traditional Chinese herb and displays diverse biological activities including antioxidation, anti-tumorigenesis, anti-virus, and anti-atherogenesis. In this study, we investigated the up-regulation of ethanolic extract of A. paniculata (APE on the antioxidant defense in rat livers and whether this enhancement protected against carbon tetrachloride (CCl4-induced liver damage. Male Sprague-Dawley rats were orally administered (i.g. 0, 0.75, or 2 g/kg/d APE for 5 d. At d 6, rats were sacrificed and liver tissues were removed. Some animals (n=8 were intraperitoneally injected CCl4 (1 mL/kg, 50% in olive oil and blood was drawn 24 h after CCl4 treatment. The results showed that APE increased hepatic glutathione (GSH content and superoxide dismutase, GSH peroxidase, and GSH S-transferase activities in a dose-dependent manner (p<0.05. Results of immunoblotting and RT-PCR revealed that rats treated with APE had higher glutamate cysteine ligase catalytic and modifier subunits, heme oxygenase 1, superoxide dismutase 1, and GSH S-transferase Ya and Yb protein and mRNA expression than those of control rats. Moreover, APE increased Nrf2 nuclear translocation and Nrf2 binding to DNA in rat liver. In the presence of CCl4, APE decreased hepatic thiobarbituric acid-reactive substances production and plasma aspartate aminotransferase and alanine aminotransferase activities. These results suggest that APE protection against CCl4 insult is attributed, at least in part, to its up-regulation of antioxidant defense in rat liver.

  2. Family History

    Science.gov (United States)

    Your family history includes health information about you and your close relatives. Families have many factors in common, including their genes, ... as heart disease, stroke, and cancer. Having a family member with a disease raises your risk, but ...

  3. A new analysis of radiation-induced cytogenetic damage in human lymphocytes using the PCC technique, and its implications for biological dosimetry and the understanding of cell-cycle-dependent radiosensitivity fluctuations

    International Nuclear Information System (INIS)

    Zannos, A.; Pantelias, G.E.

    1993-01-01

    The objectives of the project are: to develop a sensitive biological dosemeter, based on the analysis of C-banded peripheral blood lymphocyte prematurely condensed chromosomes (PCCs), for the early assessment of radiation injury and the establishment of absorbed dose estimates in accidental overexposures; and to elucidate the mechanisms of radiation action at the molecular, chromosomal and cellular levels by the study of the effects of DNA repair inhibitors on the repair of radiation damage, effects of BrdUrd incorporation on radiation damage, effects of hyperthermia on the induction and repair of radiation-induced damage, and induction and repair of radiation damage in an X-ray sensitive CHO mutant cell line. (authors) 16 refs., 1 fig

  4. An adaptive method for history dependent materials

    NARCIS (Netherlands)

    Quak, W.; van den Boogaard, Antonius H.; Khalili, Nasser; Valliappan, Somasundaram; Li, Qing; Russel, Adrian

    2010-01-01

    Introduction: Finite element simulations of bulk forming processes, like extrusion or forging, can fail due to element distortion. Simulating a forming process requires either many re-meshing steps or an Eulerian formulation to avoid this problem. This re-meshing or usage of an Eulerian formulation,

  5. History-independent cyclic response of nanotwinned metals

    Science.gov (United States)

    Pan, Qingsong; Zhou, Haofei; Lu, Qiuhong; Gao, Huajian; Lu, Lei

    2017-11-01

    Nearly 90 per cent of service failures of metallic components and structures are caused by fatigue at cyclic stress amplitudes much lower than the tensile strength of the materials involved. Metals typically suffer from large amounts of cumulative, irreversible damage to microstructure during cyclic deformation, leading to cyclic responses that are unstable (hardening or softening) and history-dependent. Existing rules for fatigue life prediction, such as the linear cumulative damage rule, cannot account for the effect of loading history, and engineering components are often loaded by complex cyclic stresses with variable amplitudes, mean values and frequencies, such as aircraft wings in turbulent air. It is therefore usually extremely challenging to predict cyclic behaviour and fatigue life under a realistic load spectrum. Here, through both atomistic simulations and variable-strain-amplitude cyclic loading experiments at stress amplitudes lower than the tensile strength of the metal, we report a history-independent and stable cyclic response in bulk copper samples that contain highly oriented nanoscale twins. We demonstrate that this unusual cyclic behaviour is governed by a type of correlated ‘necklace’ dislocation consisting of multiple short component dislocations in adjacent twins, connected like the links of a necklace. Such dislocations are formed in the highly oriented nanotwinned structure under cyclic loading and help to maintain the stability of twin boundaries and the reversible damage, provided that the nanotwins are tilted within about 15 degrees of the loading axis. This cyclic deformation mechanism is distinct from the conventional strain localizing mechanisms associated with irreversible microstructural damage in single-crystal, coarse-grained, ultrafine-grained and nanograined metals.

  6. Environmental history

    DEFF Research Database (Denmark)

    Pawson, Eric; Christensen, Andreas Aagaard

    2017-01-01

    Environmental history is an interdisciplinary pursuit that has developed as a form of conscience to counter an increasingly powerful, forward-looking liberal theory of the environment. It deals with the relations between environmental ideas and materialities, from the work of the geographers George...... risks”. These are exposed by environmental history’s focus on long-run analysis and its narrative form that identifies the stories that we tell ourselves about nature. How a better understanding of past environmental transformations helps to analyse society and agency, and what this can mean...... for solutions and policies, is the agenda for an engaged environmental history from now on....

  7. Ildens historier

    DEFF Research Database (Denmark)

    Lassen, Henrik Roesgaard

    have been written by Andersen. In several chapters the curiously forgotten history of fire-lighting technology is outlined, and it is demonstrated that "Tællelyset" is written by a person with a modern perspective on how to light a candle - among other things. The central argument in the book springs...... from a point-by-point tracing of 'the origins and history' of Hans Christian Andersen's famous fairy tales. Where did the come from? How did they become the iconic texts that we know today? On this background it becomes quite clear that "Tællelyset" is a modern pastiche and not a genuine Hans Christian...

  8. Revisiting the natural history of tuberculosis. The inclusion of constant reinfection, host tolerance, and damage-response frameworks leads to a better understanding of latent infection and its evolution towards active disease.

    Science.gov (United States)

    Cardona, Pere-Joan

    2010-02-01

    Once Mycobacterium tuberculosis infects a person it can persist for a long time in a process called latent tuberculosis infection (LTBI). LTBI has traditionally been considered to involve the bacilli remaining in a non-replicating state (dormant) in old lesions but still retaining their ability to induce reactivation and cause active tuberculosis (TB) once a disruption of the immune response takes place. The present review aims to challenge these concepts by including recent experimental data supporting LTBI as a constant endogenous reinfection process as well as the recently introduced concepts of damage-response and tolerance frameworks to explain TB induction. These frameworks highlight the key role of an exaggerated and intolerant host response against M. tuberculosis bacilli which induces the classical TB cavity in immunocompetent adults once the constant endogenous reinfection process has resulted in the presence of bacilli in the upper lobes, where they can grow faster and the immune response is delayed. This essay intends to provide new clues to understanding the induction of TB in non-immunosuppressed patients.

  9. Chapter 6: Fire damage of wood structures

    Science.gov (United States)

    B. Kukay; R.H. White; F. Woeste

    2012-01-01

    Depending on the severity, fire damage can compromise the structural integrity of wood structures such as buildings or residences. Fire damage of wood structures can incorporate several models that address (1) the type, cause, and spread of the fire, (2) the thermal gradients and fire-resistance ratings, and (3) the residual load capacity (Figure 6.1). If there is a...

  10. Damage analysis: damage function development and application

    International Nuclear Information System (INIS)

    Simons, R.L.; Odette, G.R.

    1975-01-01

    The derivation and application of damage functions, including recent developments for the U.S. LMFBR and CTR programs, is reviewed. A primary application of damage functions is in predicting component life expectancies; i.e., the fluence required in a service spectrum to attain a specified design property change. An important part of the analysis is the estimation of the uncertainty in such fluence limit predictions. The status of standardizing the procedures for the derivation and application of damage functions is discussed. Improvements in several areas of damage function development are needed before standardization can be completed. These include increasing the quantity and quality of the data used in the analysis, determining the limitations of the analysis due to the presence of multiple damage mechanisms, and finally, testing of damage function predictions against data obtained from material surveillance programs in operating thermal and fast reactors. 23 references. (auth)

  11. Business History

    DEFF Research Database (Denmark)

    Hansen, Per H.

    2012-01-01

    This article argues that a cultural and narrative perspective can enrich the business history field, encourage new and different questions and answers, and provide new ways of thinking about methods and empirical material. It discusses what culture is and how it relates to narratives. Taking...

  12. LCA History

    DEFF Research Database (Denmark)

    Bjørn, Anders; Owsianiak, Mikołaj; Molin, Christine

    2018-01-01

    The idea of LCA was conceived in the 1960s when environmental degradation and in particular the limited access to resources started becoming a concern. This chapter gives a brief summary of the history of LCA since then with a focus on the fields of methodological development, application...

  13. Rewriting History.

    Science.gov (United States)

    Ramirez, Catherine Clark

    1994-01-01

    Suggests that the telling of vivid stories can help engage elementary students' emotions and increase the chances of fostering an interest in Texas history. Suggests that incorporating elements of the process approach to writing can merge with social studies objectives in creating a curriculum for wisdom. (RS)

  14. Business History as Cultural History

    DEFF Research Database (Denmark)

    Lunde Jørgensen, Ida

    The paper engages with the larger question of how cultural heritage becomes taken for granted and offers a complimentary view to the anthropological ʻCopenhagen School’ of business history, one that draws attention to the way corporate wealth directly and indirectly influences the culture available...

  15. River history.

    Science.gov (United States)

    Vita-Finzi, Claudio

    2012-05-13

    During the last half century, advances in geomorphology-abetted by conceptual and technical developments in geophysics, geochemistry, remote sensing, geodesy, computing and ecology-have enhanced the potential value of fluvial history for reconstructing erosional and depositional sequences on the Earth and on Mars and for evaluating climatic and tectonic changes, the impact of fluvial processes on human settlement and health, and the problems faced in managing unstable fluvial systems. This journal is © 2012 The Royal Society

  16. Environmental History

    OpenAIRE

    Kearns, Gerard

    2004-01-01

    There was a time when almost all Western geography could be termed environmental history. In the late nineteenth century, physical geographers explained landscapes by describing how they had evolved. Likewise, human geographers saw society as shaped by the directing hands of the environment. By the 1960s this had very much changed. Process studies shortened the temporal framework in geographical explanation and cut the cord between nature and society. Now, physical and human...

  17. Damage nucleation in Si during ion irradiation

    International Nuclear Information System (INIS)

    Holland, O.W.; Fathy, D.; Narayan, J.

    1984-01-01

    Damage nucleation in single crystals of silicon during ion irradiation is investigated. Experimental results and mechanisms for damage nucleation during both room and liquid nitrogen temperature irradiation with different mass ions are discussed. It is shown that the accumulation of damage during room temperature irradiation depends on the rate of implantation. These dose rate effects are found to decrease in magnitude as the mass of the ions is increased. The significance of dose rate effects and their mass dependence on nucleation mechanisms is discussed

  18. Radiation damage of nonmetallic solids

    International Nuclear Information System (INIS)

    Goland, A.N.

    1975-01-01

    A review of data and information on radiation damage in nonmetallic solids is presented. Discussions are included on defects in nonmetals, radiation damage processes in nonmetals, electronic damage processes, physical damage processes, atomic displacement, photochemical damage processes, and ion implantation

  19. Femoral nerve damage (image)

    Science.gov (United States)

    The femoral nerve is located in the leg and supplies the muscles that assist help straighten the leg. It supplies sensation ... leg. One risk of damage to the femoral nerve is pelvic fracture. Symptoms of femoral nerve damage ...

  20. Does labor market history matter?

    DEFF Research Database (Denmark)

    Lesner, Rune Vammen

    2014-01-01

    This paper finds that labor market history plays an important role in the Danish labor market both by directly affecting the transitions between labor market states and indirectly through the wage. When comparing the relative importance of different types of state dependence, it is found that occ......This paper finds that labor market history plays an important role in the Danish labor market both by directly affecting the transitions between labor market states and indirectly through the wage. When comparing the relative importance of different types of state dependence, it is found...... that occurrence dependence from non-employment states seems to have the strongest effect on the employment rate, while employment history is the main driver of state dependence in the wage. Predictions based on the estimated model reveal potential negative long-term effects from external employment shocks...

  1. Uncovering History for Future History Teachers

    Science.gov (United States)

    Fischer, Fritz

    2010-01-01

    The art of history teaching is at a crossroads. Recent scholarship focuses on the need to change the teaching of history so students can better learn history, and insists that history teachers must move beyond traditional structures and methods of teaching in order to improve their students' abilities to think with history. This article presents…

  2. Reduced regional cerebral blood flow in aged noninsulin-dependent diabetic patients with no history of cerebrovascular disease: evaluation by N-isopropyl-123I-p-iodoamphetamine with single-photon emission computed tomography

    International Nuclear Information System (INIS)

    Wakisaka, M.; Nagamachi, S.; Inoue, K.; Morotomi, Y.; Nunoi, K.; Fujishima, M.

    1990-01-01

    Regional cerebral blood flow was measured using N-isopropyl- 123 I-iodoamphetamine with single-photon emission computed tomography (CT) in 16 aged patients with noninsulin-dependent diabetes mellitus (NIDDM, average age 72.8 years, average fasting plasma glucose 7.7 mmol/L), and 12 nondiabetic subjects (71.6 years, 5.3 mmol/L). None had any history of a cerebrovascular accident. Systolic blood pressure (SBP), total cholesterol, and triglyceride levels did not differ between groups. Areas of hypoperfusion were observed in 14 diabetic patients (12 patients had multiple lesions) and in 6 nondiabetic subjects (3 had multiple lesions). Areas where radioactivity was greater than or equal to 65% of the maximum count of the slice was defined as a region with normal cerebral blood flow (region of interest A, ROI-A), and areas where the count was greater than or equal to 45% were defined as brain tissue regions other than ventricles (ROI-B). The average ROI-A/B ratio of 16 slices was used as a semiquantitative indicator of normal cerebral blood flow throughout the entire brain. Mean ROI-A/B ratio was 49.6 +/- 1.7% in the diabetic group, significantly lower than the 57.9 +/- 1.6% at the nondiabetic group (p less than 0.005). The ratio was inversely correlated with SBP (r = -0.61, p less than 0.05), total cholesterol (r = -0.51, p less than 0.05), and atherogenic index (r = -0.64, p less than 0.01), and was positively correlated with high-density lipoprotein (HDL) cholesterol (r = 0.51, p less than 0.05) in the diabetic, but not the nondiabetic group. These observations suggest that the age-related reduction in cerebral blood flow may be accelerated by a combination of hyperglycemia plus other risk factors for atherosclerosis

  3. Repair of radiation damage in mammalian cells

    Energy Technology Data Exchange (ETDEWEB)

    Setlow, R.B.

    1981-01-01

    The responses, such as survival, mutation, and carcinogenesis, of mammalian cells and tissues to radiation are dependent not only on the magnitude of the damage to macromolecular structures - DNA, RNA, protein, and membranes - but on the rates of macromolecular syntheses of cells relative to the half-lives of the damages. Cells possess a number of mechanisms for repairing damage to DNA. If the repair systems are rapid and error free, cells can tolerate much larger doses than if repair is slow or error prone. It is important to understand the effects of radiation and the repair of radiation damage because there exist reasonable amounts of epidemiological data that permits the construction of dose-response curves for humans. The shapes of such curves or the magnitude of the response will depend on repair. Radiation damage is emphasized because: (a) radiation dosimetry, with all its uncertainties for populations, is excellent compared to chemical dosimetry; (b) a number of cancer-prone diseases are known in which there are defects in DNA repair and radiation results in more chromosomal damage in cells from such individuals than in cells from normal individuals; (c) in some cases, specific radiation products in DNA have been correlated with biological effects, and (d) many chemical effects seem to mimic radiation effects. A further reason for emphasizing damage to DNA is the wealth of experimental evidence indicating that damages to DNA can be initiating events in carcinogenesis.

  4. Repair of radiation damage in mammalian cells

    International Nuclear Information System (INIS)

    Setlow, R.B.

    1981-01-01

    The responses, such as survival, mutation, and carcinogenesis, of mammalian cells and tissues to radiation are dependent not only on the magnitude of the damage to macromolecular structures - DNA, RNA, protein, and membranes - but on the rates of macromolecular syntheses of cells relative to the half-lives of the damages. Cells possess a number of mechanisms for repairing damage to DNA. If the repair systems are rapid and error free, cells can tolerate much larger doses than if repair is slow or error prone. It is important to understand the effects of radiation and the repair of radiation damage because there exist reasonable amounts of epidemiological data that permits the construction of dose-response curves for humans. The shapes of such curves or the magnitude of the response will depend on repair. Radiation damage is emphasized because: (a) radiation dosimetry, with all its uncertainties for populations, is excellent compared to chemical dosimetry; (b) a number of cancer-prone diseases are known in which there are defects in DNA repair and radiation results in more chromosomal damage in cells from such individuals than in cells from normal individuals; (c) in some cases, specific radiation products in DNA have been correlated with biological effects, and (d) many chemical effects seem to mimic radiation effects. A further reason for emphasizing damage to DNA is the wealth of experimental evidence indicating that damages to DNA can be initiating events in carcinogenesis

  5. Cygnus History

    International Nuclear Information System (INIS)

    Henderson, David J.; Gignac, Raymond E.; Good, Douglas E.; Hansen, Mark D.; Mitton, Charles V.; Nelson, Daniel S.; Ormond, Eugene C.; Cordova, Steve R.; Molina, Isidro; Smith, John R.; Rose, Evan A.

    2009-01-01

    The Cygnus Dual Beam Radiographic Facility consists of two identical radiographic sources: Cygnus 1 and Cygnus 2. This Radiographic Facility is located in an underground tunnel test area at the Nevada Test Site. The sources were developed to produce high-resolution images for dynamic plutonium experiments. This work will recount and discuss salient maintenance and operational issues encountered during the history of Cygnus. A brief description of Cygnus systems and rational for design selections will set the stage for this historical narrative. It is intended to highlight the team-derived solutions for technical problems encountered during extended periods of maintenance and operation. While many of the issues are typical to pulsed power systems, some of the solutions are unique. It is hoped that other source teams will benefit from this presentation, as well as other necessary disciplines (e.g., source users, system architects, facility designers and managers, funding managers, and team leaders)

  6. Environmental history

    DEFF Research Database (Denmark)

    Pawson, Eric; Christensen, Andreas Aagaard

    2017-01-01

    Environmental history is an interdisciplinary pursuit that has developed as a form of conscience to counter an increasingly powerful, forward-looking liberal theory of the environment. It deals with the relations between environmental ideas and materialities, from the work of the geographers George...... Perkins Marsh, Carl Sauer, and Clarence Glacken, to more recent global-scale assessments of the impact of the “great acceleration” since 1950. Today’s “runaway world” paradoxically embraces risk management in an attempt to determine its own future whilst generating a whole new category of “manufactured...... risks”. These are exposed by environmental history’s focus on long-run analysis and its narrative form that identifies the stories that we tell ourselves about nature. How a better understanding of past environmental transformations helps to analyse society and agency, and what this can mean...

  7. História da enfermagem psiquiátrica e a dependência química no Brasil: atravessando a história para reflexão Historia de la enfermería psiquiátrica y la dependencia química en el Brasil: atravesando la historia para la reflexión History of the psychiatric nursing and chemical dependency in Brazil: crossing the history for reflection

    Directory of Open Access Journals (Sweden)

    Amanda Márcia dos Santos Reinaldo

    2007-12-01

    ón del enfermero profesional. Ambas temáticas encuentran puntos de aproximación y alejamiento conforme el contexto en que son analizadas.The nursing education in psychiatric nursing and in the area of chemical dependency guides the discussion of this article towards the complexity of problems related to the nursing, mental health, psychiatric and alcohol and drugs teaching. It is a literature review where the authors compiled primary and secondary sources on the theme. Analyses and reflections on historical crossings that permeate the history of the psychiatric nursing and chemical dependency in Brazil were performed on the bibliographic material. The results point to an evolution of the theme alcohol and drugs given the magnitude of the problem in the contemporaneous society. Regarding the psychiatric nursing, the teaching presents changes due to the historical evolution of the psychiatry that must be considered during the education of the nursing professional. Both themes had common and distinctive points according to the context in which they were analyzed.

  8. Damage Analysis and Evaluation of High Strength Concrete Frame Based on Deformation-Energy Damage Model

    Directory of Open Access Journals (Sweden)

    Huang-bin Lin

    2015-01-01

    Full Text Available A new method of characterizing the damage of high strength concrete structures is presented, which is based on the deformation energy double parameters damage model and incorporates both of the main forms of damage by earthquakes: first time damage beyond destruction and energy consumption. Firstly, test data of high strength reinforced concrete (RC columns were evaluated. Then, the relationship between stiffness degradation, strength degradation, and ductility performance was obtained. And an expression for damage in terms of model parameters was determined, as well as the critical input data for the restoring force model to be used in analytical damage evaluation. Experimentally, the unloading stiffness was found to be related to the cycle number. Then, a correction for this changing was applied to better describe the unloading phenomenon and compensate for the shortcomings of structure elastic-plastic time history analysis. The above algorithm was embedded into an IDARC program. Finally, a case study of high strength RC multistory frames was presented. Under various seismic wave inputs, the structural damages were predicted. The damage model and correction algorithm of stiffness unloading were proved to be suitable and applicable in engineering design and damage evaluation of a high strength concrete structure.

  9. Public History

    Directory of Open Access Journals (Sweden)

    Marta Gouveia de Oliveira Rovai

    2017-04-01

    Full Text Available Este artigo tem como proposta apresentar o conceito e as práticas de História Pública como um novo posicionamento da ciência histórica em diálogo com profissionais da comunicação, no sentido de produzir e divulgar as experiências humanas. Para isso, discute-se a origem do conceito de História Pública e as diferentes formas de educação histórica que a utilização das novas tecnologias podem proporcionar (dentre elas a internet. Nesse sentido, convida-se o leitor para a reflexão sobre as possibilidades de publicização e de democratização do conhecimento histórico e da cultura, ampliando-se a oportunidade de produção, de divulgação e de acesso do público a diferentes formas experiências no tempo. O artigo também intenciona chamar atenção dos profissionais que lidam com a História e com a Comunicação para os perigos de produções exclusivamente submetidas ao mercado que transformam a popularização da História no reforço de estigmas culturais.   PALAVRAS-CHAVE: História Pública; Educação histórica e Comunicação; democratização e estigmatização.     ABSTRACT This article aims to present the concept and practices of Public History as a new positioning of historical science in dialogue with communication professionals, in the sense of producing and disseminating human experiences. For this, the origin of the concept of Public History and the different forms of historical education that the use of the new technologies can provide (among them the Internet is discussed. In this sense, the reader is invited to reflect on the possibilities of publicizing and democratizing historical knowledge and culture, expanding the opportunity for production, dissemination and public access to different forms of experience in time. The article also intends to draw attention from professionals dealing with History and Communication to the dangers of exclusively commercialized productions that transform the popularization

  10. Seismic damage assessment of reinforced concrete containment structures

    International Nuclear Information System (INIS)

    Cho, HoHyun; Koh, Hyun-Moo; Hyun, Chang-Hun; Kim, Moon-Soo; Shin, Hyun Mock

    2003-01-01

    This paper presents a procedure for assessing seismic damage of concrete containment structures using the nonlinear time-history numerical analysis. For this purpose, two kinds of damage index are introduced at finite element and structural levels. Nonlinear finite element analysis for the containment structure applies PSC shell elements using a layered approach leading to damage indices at finite element and structural levels, which are then used to assess the seismic damage of the containment structure. As an example of such seismic damage assessment, seismic damages of the containment structure of Wolsong I nuclear power plant in Korea are evaluated against 30 artificial earthquakes generated with a wide range of PGA according to US NRC regulatory guide 1.60. Structural responses and corresponding damage index according to the level of PGA and nonlinearity are investigated. It is also shown that the containment structure behaves elastically for earthquakes corresponding to or lower than DBE. (author)

  11. Fast neutron damage in germanium detectors

    International Nuclear Information System (INIS)

    Kraner, H.W.

    1979-10-01

    The effects of fast neutron radiation damage on the performance of both Ge(Li) and Ge(HP) detectors have been studied during the past decade and will be summarized. A review of the interaction processes leading to the defect structures causing trapping will be made. The neutron energy dependence of observable damage effects will be considered in terms of interaction and defect production cross sections

  12. Pion-induced damage in silicon detectors

    CERN Document Server

    Bates, S; Glaser, M; Lemeilleur, F; León-Florián, E; Gössling, C; Kaiser, B; Rolf, A; Wunstorf, R; Feick, H; Fretwurst, E; Lindström, G; Moll, Michael; Taylor, G; Chilingarov, A G

    1995-01-01

    The damage induced by pions in silicon detectors is studied for positive and negative pions for fluence up to 10(14)cm-2 and 10(13) cm-2 respectively. Results on the energy dependence of the damage in the region of 65-330 MeV near to the  resonance are presented. The change in detector characteristics such as leakage current, charge collection efficiency and effective impurity concentration including long-term annealing effects have been studied. Comparisons to neutron and proton-induced damage are presented and discussed.

  13. Flood damage estimation of companies: A comparison of Stage-Damage-Functions and Random Forests

    Science.gov (United States)

    Sieg, Tobias; Kreibich, Heidi; Vogel, Kristin; Merz, Bruno

    2017-04-01

    The development of appropriate flood damage models plays an important role not only for the damage assessment after an event but also to develop adaptation and risk mitigation strategies. So called Stage-Damage-Functions (SDFs) are often applied as a standard approach to estimate flood damage. These functions assign a certain damage to the water depth depending on the use or other characteristics of the exposed objects. Recent studies apply machine learning algorithms like Random Forests (RFs) to model flood damage. These algorithms usually consider more influencing variables and promise to depict a more detailed insight into the damage processes. In addition they provide an inherent validation scheme. Our study focuses on direct, tangible damage of single companies. The objective is to model and validate the flood damage suffered by single companies with SDFs and RFs. The data sets used are taken from two surveys conducted after the floods in the Elbe and Danube catchments in the years 2002 and 2013 in Germany. Damage to buildings (n = 430), equipment (n = 651) as well as goods and stock (n = 530) are taken into account. The model outputs are validated via a comparison with the actual flood damage acquired by the surveys and subsequently compared with each other. This study investigates the gain in model performance with the use of additional data and the advantages and disadvantages of the RFs compared to SDFs. RFs show an increase in model performance with an increasing amount of data records over a comparatively large range, while the model performance of the SDFs is already saturated for a small set of records. In addition, the RFs are able to identify damage influencing variables, which improves the understanding of damage processes. Hence, RFs can slightly improve flood damage predictions and provide additional insight into the underlying mechanisms compared to SDFs.

  14. Apportioning liability for transborder damages

    International Nuclear Information System (INIS)

    Krause-Ablass, W.-D.

    1988-01-01

    The legal situation in the case of cross border damage being caused by reactor accidents or transportation of nuclear material through more than one country is analysed. Two questions have to be asked - which country's courts have jurisdiction over the claims for damage? and which law is applicable? In considering the jurisdiction problem, the Paris and Vienna Conventions are discussed and also other rules of jurisdiction. The way the law is applicable is discussed in the second section. When the action for liability is based on the Paris or Vienna Convention the issue of reciprocity may arise and this is discussed. After a nuclear incident a potential plaintiff may have a choice amongst various jurisdictions and various available laws. Success may depend on the right choice of the forum chosen. This is illustrated by two examples. (U.K.)

  15. Materials properties utilization in a cumulative mechanical damage function for LMFBR fuel pin failure analysis

    International Nuclear Information System (INIS)

    Jacobs, D.C.

    1977-01-01

    An overview is presented of one of the fuel-pin analysis techniques used in the CRBRP program, the cumulative mechanical damage function. This technique, as applied to LMFBR's, was developed along with the majority of models used to describe the mechanical properties and environmental behavior of the cladding (i.e., 20 percent cold-worked, 316 stainless steel). As it relates to fuel-pin analyses the Cumulative Mechanical Damage Function (CDF) continually monitors cladding integrity through steady state and transient operation; it is a time dependent function of temperature and stress which reflects the effects of both the prior mechanical history and the variations in mechanical properties caused by exposure to the reactor environment

  16. Radiation damage to mushrooms

    International Nuclear Information System (INIS)

    Sattler, P.W.

    1986-01-01

    This document contains newspaper cuttings and correspondence with various ministries in Hessen on the subject of radiation damage to mushrooms from the Odenwald area. The reader is given, amongst other things, detailed information on radiation damage to different types of mushroom in 1986. (MG) [de

  17. Animal damage to birch

    Science.gov (United States)

    James S. Jordan; Francis M. Rushmore

    1969-01-01

    A relatively few animal species are responsible for most of the reported damage to the birches. White-tailed deer, yellow-bellied sapsuckers, porcupines, moose, and hares are the major animals involved. We will review reports of damage, discuss the underlying causes, and describe possible methods of control. For example, heavy deer browsing that eliminates birch...

  18. Animal damage management handbook.

    Science.gov (United States)

    Hugh C. Black

    1994-01-01

    This handbook treats animal damage management (ADM) in the West in relation to forest, range, and recreation resources; predator management is not addressed. It provides a comprehensive reference of safe, effective, and practical methods for managing animal damage on National Forest System lands. Supporting information is included in references after each chapter and...

  19. Nuclear damage - civil liability

    International Nuclear Information System (INIS)

    Simoes, A.C.

    1980-01-01

    An analysis is made of the civil liability for nuclear damage since there is a need to adjust the existing rules to the new situations created. The conventions that set up the new disciplining rules not considered in the common law for the liability of nuclear damage are also mentioned. (A.L.) [pt

  20. DNA damage and autophagy

    International Nuclear Information System (INIS)

    Rodriguez-Rocha, Humberto; Garcia-Garcia, Aracely; Panayiotidis, Mihalis I.; Franco, Rodrigo

    2011-01-01

    Both exogenous and endogenous agents are a threat to DNA integrity. Exogenous environmental agents such as ultraviolet (UV) and ionizing radiation, genotoxic chemicals and endogenous byproducts of metabolism including reactive oxygen species can cause alterations in DNA structure (DNA damage). Unrepaired DNA damage has been linked to a variety of human disorders including cancer and neurodegenerative disease. Thus, efficient mechanisms to detect DNA lesions, signal their presence and promote their repair have been evolved in cells. If DNA is effectively repaired, DNA damage response is inactivated and normal cell functioning resumes. In contrast, when DNA lesions cannot be removed, chronic DNA damage triggers specific cell responses such as cell death and senescence. Recently, DNA damage has been shown to induce autophagy, a cellular catabolic process that maintains a balance between synthesis, degradation, and recycling of cellular components. But the exact mechanisms by which DNA damage triggers autophagy are unclear. More importantly, the role of autophagy in the DNA damage response and cellular fate is unknown. In this review we analyze evidence that supports a role for autophagy as an integral part of the DNA damage response.

  1. Metabolite Damage and Metabolite Damage Control in Plants

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, Andrew D. [Horticultural Sciences Department and; Henry, Christopher S. [Mathematics and Computer Science Division, Argonne National Laboratory, Argonne, Illinois 60439, email:; Computation Institute, University of Chicago, Chicago, Illinois 60637; Fiehn, Oliver [Genome Center, University of California, Davis, California 95616, email:; de Crécy-Lagard, Valérie [Microbiology and Cell Science Department, University of Florida, Gainesville, Florida 32611, email: ,

    2016-04-29

    It is increasingly clear that (a) many metabolites undergo spontaneous or enzyme-catalyzed side reactions in vivo, (b) the damaged metabolites formed by these reactions can be harmful, and (c) organisms have biochemical systems that limit the buildup of damaged metabolites. These damage-control systems either return a damaged molecule to its pristine state (metabolite repair) or convert harmful molecules to harmless ones (damage preemption). Because all organisms share a core set of metabolites that suffer the same chemical and enzymatic damage reactions, certain damage-control systems are widely conserved across the kingdoms of life. Relatively few damage reactions and damage-control systems are well known. Uncovering new damage reactions and identifying the corresponding damaged metabolites, damage-control genes, and enzymes demands a coordinated mix of chemistry, metabolomics, cheminformatics, biochemistry, and comparative genomics. This review illustrates the above points using examples from plants, which are at least as prone to metabolite damage as other organisms.

  2. The Rhetorical Force of History in Public Argument.

    Science.gov (United States)

    Schwartzman, Roy

    The rhetorical functions of history depend on the domain in which history is used, with no connotations of interpretive priority attaching to the social or the academic realm. The appropriation of history in support of social causes as radically opposed as socialism and fascism fuels the temptation to subsume history under ideology, with the…

  3. Bortezomib-induced sensitization of malignant human glioma cells to vorinostat-induced apoptosis depends on reactive oxygen species production, mitochondrial dysfunction, Noxa upregulation, Mcl-1 cleavage, and DNA damage.

    Science.gov (United States)

    Premkumar, Daniel R; Jane, Esther P; Agostino, Naomi R; DiDomenico, Joseph D; Pollack, Ian F

    2013-02-01

    Glioblastomas are invasive tumors with poor prognosis despite current therapies. Histone deacetylase inhibitors (HDACIs) represent a class of agents that can modulate gene expression to reduce tumor growth, and we and others have noted some antiglioma activity from HDACIs, such as vorinostat, although insufficient to warrant use as monotherapy. We have recently demonstrated that proteasome inhibitors, such as bortezomib, dramatically sensitized highly resistant glioma cells to apoptosis induction, suggesting that proteasomal inhibition may be a promising combination strategy for glioma therapeutics. In this study, we examined whether bortezomib could enhance response to HDAC inhibition in glioma cells. Although primary cells from glioblastoma multiforme (GBM) patients and established glioma cell lines did not show significant induction of apoptosis with vorinostat treatment alone, the combination of vorinostat plus bortezomib significantly enhanced apoptosis. The enhanced efficacy was due to proapoptotic mitochondrial injury and increased generation of reactive oxygen species. Our results also revealed that combination of bortezomib with vorinostat enhanced apoptosis by increasing Mcl-1 cleavage, Noxa upregulation, Bak and Bax activation, and cytochrome c release. Further downregulation of Mcl-1 using shRNA enhanced cell killing by the bortezomib/vorinostat combination. Vorinostat induced a rapid and sustained phosphorylation of histone H2AX in primary GBM and T98G cells, and this effect was significantly enhanced by co-administration of bortezomib. Vorinostat/bortezomib combination also induced Rad51 downregulation, which plays an important role in the synergistic enhancement of DNA damage and apoptosis. The significantly enhanced antitumor activity that results from the combination of bortezomib and HDACIs offers promise as a novel treatment for glioma patients. Copyright © 2011 Wiley Periodicals, Inc.

  4. Celebrate Women's History.

    Science.gov (United States)

    Leonard, Carolyn M.; Baradar, Mariam

    This teachers' guide to activities celebrating Women's History Month focuses on women whose important contributions have been omitted from history textbooks. Women's History Month grew from a 1977 celebration of Women's History Week and is intended to bring women's history into the school curriculum. International Women's Day, celebrated on March…

  5. Brain damage and addictive behavior: a neuropsychological and electroencephalogram investigation with pathologic gamblers.

    Science.gov (United States)

    Regard, Marianne; Knoch, Daria; Gütling, Eva; Landis, Theodor

    2003-03-01

    Gambling is a form of nonsubstance addiction classified as an impulse control disorder. Pathologic gamblers are considered healthy with respect to their cognitive status. Lesions of the frontolimbic systems, mostly of the right hemisphere, are associated with addictive behavior. Because gamblers are not regarded as "brain-lesioned" and gambling is nontoxic, gambling is a model to test whether addicted "healthy" people are relatively impaired in frontolimbic neuropsychological functions. Twenty-one nonsubstance dependent gamblers and nineteen healthy subjects underwent a behavioral neurologic interview centered on incidence, origin, and symptoms of possible brain damage, a neuropsychological examination, and an electroencephalogram. Seventeen gamblers (81%) had a positive medical history for brain damage (mainly traumatic head injury, pre- or perinatal complications). The gamblers, compared with the controls, were significantly more impaired in concentration, memory, and executive functions, and evidenced a higher prevalence of non-right-handedness (43%) and, non-left-hemisphere language dominance (52%). Electroencephalogram (EEG) revealed dysfunctional activity in 65% of the gamblers, compared with 26% of controls. This study shows that the "healthy" gamblers are indeed brain-damaged. Compared with a matched control population, pathologic gamblers evidenced more brain injuries, more fronto-temporo-limbic neuropsychological dysfunctions and more EEG abnormalities. The authors thus conjecture that addictive gambling may be a consequence of brain damage, especially of the frontolimbic systems, a finding that may well have medicolegal consequences.

  6. Statistical Discrimination of Steady State Shift Damage Localization Metrics

    DEFF Research Database (Denmark)

    Bull, Thomas; Markvart, Morten Kusk; Sekjær, Claus

    2017-01-01

    . This postulated damage pattern is – depending on the type of damage one seeks to interrogate for – cast as a stiffness or mass perturbation in a theoretical model. The damage is hereby localized when the overlap between the experimental and analytical subspaces, under ideal conditions, is complete. Obviously...... with a cantilevered residential-sized wind turbine blade, which is exposed to a harmonic input and with the output taken as accelerations captured along the blade edges. Damage is manifested as a stiffness change and the damage localization interrogation will be carried out accordingly....

  7. History of the Buttonhole Technique.

    Science.gov (United States)

    Misra, Madhukar

    2015-01-01

    The constant side method of access cannulation in hemodialysis, popularly known as the 'buttonhole' method, has an interesting history. Dr. Zbylut J. Twardowski, a Polish nephrologist, discovered this technique by pure serendipity in 1972. A patient with a complicated vascular access history and limited options for cannulation was repeatedly 'stuck' at the same sites by a nurse. Soon it was noticed that the cannulation at the same spot became easier with time. Since the needles were being reused, the sharpness of the needles decreased with time and the bluntness of the needle seemed to minimize the damage to the cannulation tract (another serendipity!). This method soon became popular among patients, and many patients started using this technique. This chapter traces the invention of this technique and its subsequent development following Dr. Twardowski's emigration to the USA. © 2015 S. Karger AG, Basel.

  8. Lessons of nuclear robot history

    International Nuclear Information System (INIS)

    Oomichi, Takeo

    2014-01-01

    Severe accidents occurred at Fukushima Daiichi Nuclear Power Station stirred up people's great expectation of nuclear robot's deployment. However unexpected nuclear disaster, especially rupture of reactor building caused by core meltdown and hydrogen explosion, made it quite difficult to introduce nuclear robot under high radiation environment to cease accidents and dispose damaged reactor. Robotics Society of Japan (RSJ) set up committee to look back upon lessons learned from 50 year's past experience of nuclear robot development and summarized 'Lessons of nuclear robot history', which was shown on the home page website of RSJ. This article outlined it with personal comment. History of nuclear robot developed for inspection and maintenance at normal operation and for specific required response at nuclear accidents was reviewed with many examples at home and abroad for TMI, Chernobyl and JCO accidents. Present state of Fukushima accident response robot's introduction and development was also described with some comments on nuclear robot development from academia based on lessons. (T. Tanaka)

  9. Macroscopic morphology of radiation damage in copper

    International Nuclear Information System (INIS)

    Black, K.E.

    1977-01-01

    This Thesis describes the damage produced in copper single crystals when they are irradiated with neutrons from a nuclear reactor, and shows that the morphology of the damage is dependent on the temperature of irradiation. The production of point defects in the initial stages of the bombardment and their subsequent diffusion is described in Chapter One. Chapter Two describes the techniques used to etch and thus make visible the damage regions. The defect clusters were examined with a microscope. A typical selection of micrographs of the damage is presented and discussed in Chapter Three. In the final chapter, Chapter Four, the results of the present work are discussed in the light of work done by other research workers. The Thesis ends with a brief suggestion for future work to be carried out on neutron irradiated copper single crystals

  10. Epigenetic-based combinatorial resveratrol and pterostilbene alters DNA damage response by affecting SIRT1 and DNMT enzyme expression, including SIRT1-dependent γ-H2AX and telomerase regulation in triple-negative breast cancer

    International Nuclear Information System (INIS)

    Kala, Rishabh; Shah, Harsh N.; Martin, Samantha L.; Tollefsbol, Trygve O.

    2015-01-01

    Nutrition is believed to be a primary contributor in regulating gene expression by affecting epigenetic pathways such as DNA methylation and histone modification. Resveratrol and pterostilbene are phytoalexins produced by plants as part of their defense system. These two bioactive compounds when used alone have been shown to alter genetic and epigenetic profiles of tumor cells, but the concentrations employed in various studies often far exceed physiologically achievable doses. Triple-negative breast cancer (TNBC) is an often fatal condition that may be prevented or treated through novel dietary-based approaches. HCC1806 and MDA-MB-157 breast cancer cells were used as TNBC cell lines in this study. MCF10A cells were used as control breast epithelial cells to determine the safety of this dietary regimen. CompuSyn software was used to determine the combination index (CI) for drug combinations. Combinatorial resveratrol and pterostilbene administered at close to physiologically relevant doses resulted in synergistic (CI <1) growth inhibition of TNBCs. SIRT1, a type III histone deacetylase (HDAC), was down-regulated in response to this combinatorial treatment. We further explored the effects of this novel combinatorial approach on DNA damage response by monitoring γ-H2AX and telomerase expression. With combination of these two compounds there was a significant decrease in these two proteins which might further resulted in significant growth inhibition, apoptosis and cell cycle arrest in HCC1806 and MDA-MB-157 breast cancer cells, while there was no significant effect on cellular viability, colony forming potential, morphology or apoptosis in control MCF10A breast epithelial cells. SIRT1 knockdown reproduced the effects of combinatorial resveratrol and pterostilbene-induced SIRT1 down-regulation through inhibition of both telomerase activity and γ-H2AX expression in HCC1806 breast cancer cells. As a part of the repair mechanisms and role of SIRT1 in recruiting DNMTs

  11. LSD and Genetic Damage

    Science.gov (United States)

    Dishotsky, Norman I.; And Others

    1971-01-01

    Reviews studies of the effects of lysergic acid diethylamide (LSD) on man and other organisms. Concludes that pure LSD injected in moderate doses does not cause chromosome or detectable genetic damage and is not a teratogen or carcinogen. (JM)

  12. Diabetes and nerve damage

    Science.gov (United States)

    Diabetic neuropathy; Diabetes - neuropathy; Diabetes - peripheral neuropathy ... In people with diabetes, the body's nerves can be damaged by decreased blood flow and a high blood sugar level. This condition is ...

  13. Benefits of invasion prevention: Effect of time lags, spread rates, and damage persistence

    Science.gov (United States)

    Rebecca S. Epanchin-Niell; Andrew M. Liebhold

    2015-01-01

    Quantifying economic damages caused by invasive species is crucial for cost-benefit analyses of biosecurity measures. Most studies focus on short-term damage estimates, but evaluating exclusion or prevention measures requires estimates of total anticipated damages from the time of establishment onward. The magnitude of such damages critically depends on the timing of...

  14. Modeling laser damage to the retina

    Science.gov (United States)

    Clark, Clifton D.

    This dissertation presents recent progress in several areas related to modeling laser damage to the retina. In Chapter 3, we consider the consequences of using the Arrhenius damage model to predict the damage thresholds of multiple pulse, or repetitive pulse, exposures. We have identified a few fundamental trends associated with the multiple pulse damage predictions made by the Arrhenius model. These trends differ from what would be expected by non-thermal mechanisms, and could prove useful in differentiating thermal and non-thermal damage. Chapter 4 presents a new rate equation damage model hypothesized to describe photochemical damage. The model adds a temperature dependent term to the simple rate equation implied by the principle of reciprocity that is characteristic of photochemical damage thresholds. A recent damage threshold study, conducted in-vitro, has revealed a very sharp transition between thermal and photochemical damage threshold trends. For the wavelength used in the experiment (413 nm), thermal damage thresholds were observed at exposure levels that were twice the expected photochemical damage threshold, based on the traditional understanding of photochemical damage. Our model accounts for this observed trend by introducing a temperature dependent quenching, or repair, rate to the photochemical damage rate. For long exposures that give a very small temperature rise, the model reduces to the principle of reciprocity. Near the transition region between thermal and photochemical damage, the model allows the damage threshold to be set by thermal mechanisms, even at exposure above the reciprocity exposure. In Chapter 5, we describe a retina damage model that includes thermal lensing in the eye by coupling beam propagation and heat transfer models together. Thermal lensing has recently been suggested as a contributing factor to the large increase in measured retinal damage thresholds in the near infrared. The transmission of the vitreous decreases

  15. DNA damage repair and radiosensitivity

    International Nuclear Information System (INIS)

    Suzuki, Norio

    2003-01-01

    Tailored treatment is not new in radiotherapy; it has been the major subject for the last 20-30 years. Radiation responses and RBE (relative biological effectiveness) depend on assay systems, endpoints, type of tissues and tumors, radiation quality, dose rate, dose fractionation, physiological and environmental factors etc, Latent times to develop damages also differ among tissues and endpoints depending on doses and radiation quality. Recent progress in clarification of radiation induced cell death, especially of apoptotic cell death, is quite important for understanding radiosensitivity of tumor cure process as well as of tumorigenesis. Apoptotic cell death as well as dormant cells had been unaccounted and missed into a part of reproductive cell death. Another area of major progress has been made in clarifying repair mechanisms of radiation damage, i.e., non-homologous end joining (NHEJ) and homologous recombinational repair (HRR). New approaches and developments such as cDNA or protein micro arrays and so called informatics in addition to basic molecular biological analysis are expected to aid identifying molecules and their roles in signal transduction pathways, which are multi-factorial and interactive each other being involved in radiation responses. (authors)

  16. Case histories as evidence.

    Science.gov (United States)

    Herxheimer, Andrew; Healy, David; Menkes, David B

    2012-01-01

    In courts case histories play a central part when a crime may have resulted from an effect of a prescribed drug; in civil cases where a person may have suffered damage from a drug; and in coroners' enquiries into the cause of unexplained deaths. The court must decide two important questions: 1. Can the suspected medication(s) cause this kind of effect? 2. Did it (or they) do so in this particular case? Many judges and coroners have not addressed these questions clearly and have not used expert witnesses consistently, on occasion disregarding scientific evidence. Courts need to appoint experts to explain and interpret the scientific evidence. Few judges are equipped to resolve contradictions between different experts. Brief accounts of five cases from four countries illustrate these points. The reluctance of legal processes to implicate drugs as a possible cause of violent behaviour leads to injustice. Courts must be required to obtain appropriate expert evidence, and be given independent data on which drugs can cause such behaviour.

  17. HISTORY OF NEUROPSYCHOLOGICAL REHABILITATION

    Directory of Open Access Journals (Sweden)

    N. A. Varako

    2014-01-01

    Full Text Available ABSTRACT. The article reviews the history of neuropsychological rehabilitation. It begins with the description of first rehabilitation programs developed by Paul Broca and Shepherd Franz. Franz’s experimental work for motor recovery in monkeys and correlation between active movement or affected limb immobilization and rehabilitation outcomes are described in further details. Special focus is given on ideas of famous German neurologist and psychiatrist Kurt Goldstein, who laid the foundation for modern approach in rehabilitation. Goldstein developed the idea of connection between rehabilitation and patient’s daily life. He also pointed out the necessity of psychological care of patients with brain damage.Russian neuropsychological approach is presented by its founders L.S. Vygotskiy and A.R. Luriya. Aspects of higher mental processes structure and options of its correction such as “cognitive prosthesis” are described in the sense of the approach.Y. Ben-Yishay, G. Prigatano, B. Wilson represent neuropsychological rehabilitation of the second half of the 20th century. The idea of a holistic approach for rehabilitation consists of such important principles as patient’s active involvement in a process of rehabilitation, work of a special team of rehabilitation professionals, inclusion of patient’s family members. The short review of a new rehabilitation approach for patients in coma, vegetative states and critical patients under resuscitation is given. 

  18. Confabulations: a conceptual history.

    Science.gov (United States)

    Berrios, G E

    1998-12-01

    Confabulations are inaccurate or false narratives purporting to convey information about world or self. It is the received view that they are uttered by subjects intent on "covering up" for a putative memory deficit. The epidemiology of confabulations is unknown. Speculated causes include amnesia, embarrassment, "frontal lobe" damage, a subtype of "personality", a dream-like event, and a disturbance of the self. Historical analysis shows that "confabulation" was constructed at the turn of the century as part of a network of concepts (e.g. delusion, fixed idea, etc.) meant to capture narratives with dubious content. This paper deals with the history of the construction of the word and concept of confabulation and with earlier recognitions of the behaviours that serve as their referent and puts forward a model based on historical data. Two phenomena are included under "confabulation": "untrue" utterances by subjects with memory impairment and "fantastic" utterances marshalled with conviction by subjects suffering from psychoses and no memory deficit. Under different disguises, the "covering up" or "gap filling" hypothesis is still going strong. Although superficially plausible, it poses problems in regards to the issue of "awareness of purpose": if full awareness is presumed then the semantics of the concept of "purpose" is severely stretched and confabulations cannot be differentiated from delusions.

  19. Social History and Historical Sociology

    Directory of Open Access Journals (Sweden)

    Wolfgang Knöbl

    2018-01-01

    Full Text Available This paper deals with exchanges and misunderstandings between the German school of social history (most prominently represented by scholars from the University of Bielefeld (such as Hans-Ulrich Wehler and Anglo-American trends in historical sociology (exemplified by the works of Barrington Moore, Theda Skocpol and Michael Mann. The social historians tended to dismiss historical sociology as too dependent on modernization theory, without taking into account the critique of that tradition by authors who brought processes of state formation and revolutionary change into the debate. On the other side, mainstream historical sociology worked with assumptions that limited its ability to change the terms and directions of sociological discourse, and to assimilate lessons from history. Among these inbuilt biases, organizational realism and materialism – particularly pronounced in the work of Michael Mann – stand out as particularly important. The paper closes with arguments in favour of bringing more history into historical sociology, with particular emphasis on three sets of problems. There is a need for more historical approaches to differentiation, less dependent on functionalist premises than the hitherto prevalent paradigm. A more explicit thematization of temporality in history and society would, among other things, help to clarify issues linked to the notion of path dependency. Finally, a reconsideration of the models and types of explanation in historical sociology would place more emphasis on their interpretive dimension.

  20. Social History and Historical Sociology

    Directory of Open Access Journals (Sweden)

    Wolfgang Knöbl

    2013-06-01

    Full Text Available This paper deals with exchanges and misunderstandings between the German school of social history (most prominently represented by scholars from the University of Bielefeld (such as Hans-Ulrich Wehler and Anglo-American trends in historical sociology (exemplified by the works of Barrington Moore, Theda Skocpol and Michael Mann. The social historians tended to dismiss historical sociology as too dependent on modernization theory, without taking into account the critique of that tradition by authors who brought processes of state formation and revolutionary change into the debate. On the other side, mainstream historical sociology worked with assumptions that limited its ability to change the terms and directions of sociological discourse, and to assimilate lessons from history. Among these inbuilt biases, organizational realism and materialism - particularly pronounced in the work of Michael Mann - stand out as particularly important. The paper closes with arguments in favour of bringing more history into historical sociology, with particular emphasis on three sets of problems. There is a need for more historical approaches to differentiation, less dependent on functionalist premises than the hitherto prevalent paradigm. A more explicit thematization of temporality in history and society would, among other things, help to clarify issues linked to the notion of path dependency. Finally, a reconsideration of the models and types of explanation in historical sociology would place more emphasis on their interpretive dimension.

  1. Cytometric analysis of irradiation damaged chromosomes

    International Nuclear Information System (INIS)

    Wilder, M.E.; Raju, M.R.

    1982-01-01

    Irradiation of cells in interphase results in dose-dependent damage to DNA which is discernable by flow-cytometric analysis of chromosomes. The quantity (and possibly the quality) of chromosomal changes is different in survival-matched doses of x and α irradiation. It may, therefore, be possible to use these methods for analysis of dose and type of exposure in unknown cases

  2. Lessons from the Mexican earthquake 1985: Quantitative evaluation of damage and damage parameters

    International Nuclear Information System (INIS)

    Tiedemann, H.

    1992-01-01

    In Mexico City, all buildings of more than 5 storeys were inspected in order to assess the relative importance of different damage parameters. The general mean damage (MDR) was 32.1%; ranging between 94.13% for 2% g buildings and 1.89% for 10% g buildings. Stiff buildings had much lower MDR's than soft ones. Irregularity and asymmetry increased MDR's significantly. The MDR's of oblong buildings strongly depended on their orientation. Most of the overall damage resulted from failure of non-structural items. The paper presents a detailed account of these findings and the salient lessons to be learned from them. (author). 13 refs, 1 fig., 1 tab

  3. Damage Detection of Reinforced Concrete Shear Walls Using Mathematical Transformations

    Directory of Open Access Journals (Sweden)

    Hosein Naderpour

    2017-02-01

    Full Text Available Structural health monitoring is a procedure to provide accurate and immediate information on the condition and efficiency of structures. There is variety of damage factors and the unpredictability of future damage, is a necessity for the use of structural health monitoring. Structural health monitoring and damage detection in early stages is one of the most interesting topics that had been paid attention because the majority of damages can be repaired and reformed by initial evaluation ,thus the spread of damage to the structures, building collapse and rising of costs can be avoided .Detection of concrete shear wall damages are designed to withstand the lateral load on the structure is critical .Because failures and  malfunctions of shear walls can lead to serious damage or even progressive dilapidation of concrete structures .Change in stiffness and frequency can clearly show the damage occurrence. Mathematical transformation is also a tool to detect damage. In this article, with non- linear time history analysis, the finite element model of structures with concrete shear walls subject to four earthquakes have extracted and using Fourier and wavelet transform, the presence of shear walls is detected at the time of damage.

  4. Metabolite damage and repair in metabolic engineering design.

    Science.gov (United States)

    Sun, Jiayi; Jeffryes, James G; Henry, Christopher S; Bruner, Steven D; Hanson, Andrew D

    2017-11-01

    The necessarily sharp focus of metabolic engineering and metabolic synthetic biology on pathways and their fluxes has tended to divert attention from the damaging enzymatic and chemical side-reactions that pathway metabolites can undergo. Although historically overlooked and underappreciated, such metabolite damage reactions are now known to occur throughout metabolism and to generate (formerly enigmatic) peaks detected in metabolomics datasets. It is also now known that metabolite damage is often countered by dedicated repair enzymes that undo or prevent it. Metabolite damage and repair are highly relevant to engineered pathway design: metabolite damage reactions can reduce flux rates and product yields, and repair enzymes can provide robust, host-independent solutions. Herein, after introducing the core principles of metabolite damage and repair, we use case histories to document how damage and repair processes affect efficient operation of engineered pathways - particularly those that are heterologous, non-natural, or cell-free. We then review how metabolite damage reactions can be predicted, how repair reactions can be prospected, and how metabolite damage and repair can be built into genome-scale metabolic models. Lastly, we propose a versatile 'plug and play' set of well-characterized metabolite repair enzymes to solve metabolite damage problems known or likely to occur in metabolic engineering and synthetic biology projects. Copyright © 2017 International Metabolic Engineering Society. All rights reserved.

  5. Metabolite damage and repair in metabolic engineering design

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Jiayi; Jeffryes, James G.; Henry, Christopher S.; Bruner, Steven D.; Hanson, Andrew D.

    2017-11-01

    The necessarily sharp focus of metabolic engineering and metabolic synthetic biology on pathways and their fluxes has tended to divert attention from the damaging enzymatic and chemical side-reactions that pathway metabolites can undergo. Although historically overlooked and underappreciated, such metabolite damage reactions are now known to occur throughout metabolism and to generate (formerly enigmatic) peaks detected in metabolomics datasets. It is also now known that metabolite damage is often countered by dedicated repair enzymes that undo or prevent it. Metabolite damage and repair are highly relevant to engineered pathway design: metabolite damage reactions can reduce flux rates and product yields, and repair enzymes can provide robust, host-independent solutions. Herein, after introducing the core principles of metabolite damage and repair, we use case histories to document how damage and repair processes affect efficient operation of engineered pathways - particularly those that are heterologous, non-natural, or cell-free. We then review how metabolite damage reactions can be predicted, how repair reactions can be prospected, and how metabolite damage and repair can be built into genome-scale metabolic models. Lastly, we propose a versatile 'plug and play' set of well-characterized metabolite repair enzymes to solve metabolite damage problems known or likely to occur in metabolic engineering and synthetic biology projects.

  6. Comparison of Two Models for Damage Accumulation in Simulations of System Performance

    Energy Technology Data Exchange (ETDEWEB)

    Youngblood, R. [Idaho National Laboratory, Idaho Falls, ID (United States); Mandelli, D. [Idaho National Laboratory, Idaho Falls, ID (United States)

    2015-11-01

    A comprehensive simulation study of system performance needs to address variations in component behavior, variations in phenomenology, and the coupling between phenomenology and component failure. This paper discusses two models of this: 1. damage accumulation is modeled as a random walk process in each time history, with component failure occurring when damage accumulation reaches a specified threshold; or 2. damage accumulation is modeled mechanistically within each time history, but failure occurs when damage reaches a time-history-specific threshold, sampled at time zero from each component’s distribution of damage tolerance. A limiting case of the latter is classical discrete-event simulation, with component failure times sampled a priori from failure time distributions; but in such models, the failure times are not typically adjusted for operating conditions varying within a time history. Nowadays, as discussed below, it is practical to account for this. The paper compares the interpretations and computational aspects of the two models mentioned above.

  7. Picosecond laser damage of fused silica at 355 nm

    International Nuclear Information System (INIS)

    Meng Xiangjie; Liu Hongjie; Wang Fang; Zhang Zhen; An Xinyou; Huang Jin; Jiang Xiaodong; Wu Weidong; Ren Weiyi

    2013-01-01

    This paper studies the initiated damage threshold, the damage morphology and the subsequent damage growth on fused silica's input-surface and exit-surface under picosecond laser irradiation at 355 nm. Defects induced fluorescence on surface of the optical component is observed. The results demonstrate a significant dependence of the initiated damage on pulse duration and surface defects, and that of the damage growth on self-focusing, sub-surface defects. The damage-threshold is 3.98 J/cm 2 of input surface and 2.91 J/cm 2 of exit surface. The damage morphologies are quite different between input surface and exit surface. Slow growth behavior appears for the diameter of exit-surface and linear growth one for the depth of exit-surface in the lateral side of damage site with the increase of shot number. Defects have changed obviously compared with nanosecond laser damage in the damage area. Several main reasons such as electric intensification and self-focusing for the observed initiated damage and damage growth behavior are discussed. (authors)

  8. Health effects of radiation damage

    International Nuclear Information System (INIS)

    Gasimova, K; Azizova, F; Mehdieva, K.

    2012-01-01

    Full text : A summary of the nature of radiactive contamination would be incomplete without some mention of the human health effects relatied to radioactivity and radioactive materials. Several excellent reviews at the variety of levels of detail have been written and should be consulted by the reader. Internal exposures of alpha and beta particles are important for ingested and inhaled radionuclides. Dosimetry models are used to estimate the dose from internally deposited radioactive particles. As mentioned above weighting parameters that take into account the radiation type, the biological half-life and the tissue or organ at risk are used to convert the physically absorbed dose in units of gray (or red) to the biologically significant committed equivalent dose and effective dose, measured in units of Sv (or rem). There is considerable controversy over the shape of the dose-response curve at the chronic low dose levels important for enviromental contamination. Proposed models include linear models, non-linear models and threshold models. Because risks at low dose must be extrapolated from available date at high doses, the shape of the dose-response curve has important implications for the environmental regulations used to protect the general public. The health effect of radiation damage depends on a combination of events of on the cellular, tissue and systemic levels. These lead to mutations and cellular of the irradiated parent cell. The dose level at which significant damage occurs depends on the cell type. Cells that reproduce rapidily, such as those found in bone marrow or the gastrointestinal tract, will be more sensitive to radiation than those that are longer lived, such as striated muscle or nerve cells. The effects of high radiation doses on an organ depends on the various cell types it contains

  9. Study on inelastic analysis method for structural design (1). Estimation method of loading history effect

    International Nuclear Information System (INIS)

    Tanaka, Yoshihiko; Kasahara, Naoto

    2003-05-01

    The advanced loop-type reactor system, one of the promising concepts in the Feasibility study of the FBR Cycle, adopts many innovative ideas to meet the challenging requirements for safety and economy. As a results, it seems that the structures of the reactor system would be subjected to severer loads than the predecessors. One of the countermeasures to them is the design by inelastic analysis. In the past, many studies showed that structural design by inelastic analysis is much more reasonable than one by conservative elastic analysis. However, inelastic analysis has hardly been adopted in nuclear design so far. One of the reasons is that inelastic analysis has loading history effect, that is, the analysis result would differ depending on the order of loads. It seems to be difficult to find the general solution for the loading history effect. Consequently, inelastic analysis output from the four deferent thermal load histories which consists of the thermal load cycle including the severest cold shock ('C') and the one including the severest hot shock ('H') were compared with each other. From this comparison, it was revealed that the thermal load history with evenly distributed 'H's among 'C's tend to give the most conservative damage estimation derived from inelastic analysis output. Therefore, such thermal load history pattern is proposed for the structural design by inelastic analysis. (author)

  10. Impact damage in aircraft composite sandwich panels

    Science.gov (United States)

    Mordasky, Matthew D.

    An experimental study was conducted to develop an improved understanding of the damage caused by runway debris and environmental threats on aircraft structures. The velocities of impacts for stationary aircraft and aircraft under landing and takeoff speeds was investigated. The impact damage by concrete, asphalt, aluminum, hail and rubber sphere projectiles was explored in detail. Additionally, a kinetic energy and momentum experimental study was performed to look at the nature of the impacts in more detail. A method for recording the contact force history of the impact by an instrumented projectile was developed and tested. The sandwich composite investigated was an IM7-8552 unidirectional prepreg adhered to a NOMEXRTM core with an FM300K film adhesive. Impact experiments were conducted with a gas gun built in-house specifically for delivering projectiles to a sandwich composite target in this specic velocity regime (10--140 m/s). The effect on the impact damage by the projectile was investigated by ultrasonic C-scan, high speed camera and scanning electron and optical microscopy. Ultrasonic C-scans revealed the full extent of damage caused by each projectile, while the high speed camera enabled precise projectile velocity measurements that were used for striking velocity, kinetic energy and momentum analyses. Scanning electron and optical images revealed specific features of the panel failure and manufacturing artifacts within the lamina and honeycomb core. The damage of the panels by different projectiles was found to have a similar damage area for equivalent energy levels, except for rubber which had a damage area that increased greatly with striking velocity. Further investigation was taken by kinetic energy and momentum based comparisons of 19 mm diameter stainless steel sphere projectiles in order to examine the dominating damage mechanisms. The sandwich targets were struck by acrylic, aluminum, alumina, stainless steel and tungsten carbide spheres of the

  11. NOAA History - Main Page

    Science.gov (United States)

    NOAA History Banner gold bar divider home - takes you to index page about the site contacts noaa americas science and service noaa legacy 1807 - 2007 NOAA History is an intrinsic part of the history of Initiative scroll divider More NOAA History from Around the Nation scroll divider drawing of a tornado NOAA

  12. Reinventing Entrepreneurial History

    DEFF Research Database (Denmark)

    Wadhwani, R. Daniel; Lubinski, Christina

    2017-01-01

    Research on entrepreneurship remains fragmented in business history. A lack of conceptual clarity inhibits comparisons between studies and dialogue among scholars. To address these issues, we propose to reinvent entrepreneurial history as a research field. We define “new entrepreneurial history...... and reconfiguring resources, and legitimizing novelty. The article elaborates on the historiography, premises, and potential contributions of new entrepreneurial history....

  13. Kiropraktikkens historie i Danmark

    DEFF Research Database (Denmark)

    Jørgensen, Per

    Bogen er den første samlede, forskningsbaserede fremstilling om kiropraktikkens danske historie. Den har udblik til kiropraktikkens historie i USA.......Bogen er den første samlede, forskningsbaserede fremstilling om kiropraktikkens danske historie. Den har udblik til kiropraktikkens historie i USA....

  14. Fatigue damage mechanics of notched graphite-epoxy laminates

    Science.gov (United States)

    Spearing, Mark; Beaumont, Peter W. R.; Ashby, Michael F.

    A modeling approach is presented that recognizes that the residual properties of composite laminates after any form of loading depend on the damage state. Therefore, in the case of cyclic loading, it is necessary to first derive a damage growth law and then relate the residual properties to the accumulated damage. The propagation of fatigue damage in notched laminates is investigated. A power law relationship between damage growth and the strain energy release rate is developed. The material constants used in the model have been determined in independent experiments and are invariant for all the layups investigated. The strain energy release rates are calculated using a simple finite element representation of the damaged specimen. The model is used to predict the effect of tension-tension cyclic loading on laminates of the T300/914C carbon-fiber epoxy system. The extent of damage propagation is successfully predicted in a number of cross-ply laminates.

  15. Laser damage studies on MgF2 thin films

    International Nuclear Information System (INIS)

    Protopapa, Maria Lucia; De Tomasi, Ferdinando; Perrone, Maria Rita; Piegari, Angela; Masetti, Enrico; Ristau, Detlev; Quesnel, Etienne; Duparre, Angela

    2001-01-01

    The results of laser damage studies performed at 248 nm (KrF excimer laser) on MgF 2 thin films deposited by different techniques (electron-beam evaporation, thermal boat evaporation, and ion-beam sputtering) on fused silica and CaF 2 substrates are presented. We find that the films deposited on CaF 2 substrates by the electron-beam evaporation technique present the highest damage threshold fluence (9 J/cm2). The photoacoustic (PA) beam deflection technique was employed, in addition to microscopical inspection, to determine laser damage fluences. We confirm, by scanning electron microscopy analysis of the damaged spots, the capability of the PA technique to provide information on the mechanisms leading to damage. The dependence of both laser damage fluence and damage morphology on the film deposition technique, as well as on the film substrate, is discussed

  16. Towards Coupling of Macroseismic Intensity with Structural Damage Indicators

    Science.gov (United States)

    Kouteva, Mihaela; Boshnakov, Krasimir

    2016-04-01

    Knowledge on basic data of ground motion acceleration time histories during earthquakes is essential to understanding the earthquake resistant behaviour of structures. Peak and integral ground motion parameters such as peak ground motion values (acceleration, velocity and displacement), measures of the frequency content of ground motion, duration of strong shaking and various intensity measures play important roles in seismic evaluation of existing facilities and design of new systems. Macroseismic intensity is an earthquake measure related to seismic hazard and seismic risk description. Having detailed ideas on the correlations between the earthquake damage potential and macroseismic intensity is an important issue in engineering seismology and earthquake engineering. Reliable earthquake hazard estimation is the major prerequisite to successful disaster risk management. The usage of advanced earthquake engineering approaches for structural response modelling is essential for reliable evaluation of the accumulated damages in the existing buildings and structures due to the history of seismic actions, occurred during their lifetime. Full nonlinear analysis taking into account single event or series of earthquakes and the large set of elaborated damage indices are suitable contemporary tools to cope with this responsible task. This paper presents some results on the correlation between observational damage states, ground motion parameters and selected analytical damage indices. Damage indices are computed on the base of nonlinear time history analysis of test reinforced structure, characterising the building stock of the Mediterranean region designed according the earthquake resistant requirements in mid XX-th century.

  17. Coal transportation road damage

    International Nuclear Information System (INIS)

    Burtraw, D.; Harrison, K.; Pawlowski, J.A.

    1994-01-01

    Heavy trucks are primarily responsible for pavement damage to the nation's highways. In this paper we evaluate the pavement damage caused by coal trucks. We analyze the chief source of pavement damage (vehicle weight per axle, not total vehicle weight) and the chief cost involved (the periodic overlay that is required when a road's surface becomes worn). This analysis is presented in two stages. In the first section we present a synopsis of current economic theory including simple versions of the formulas that can be: used to calculate costs of pavement wear. In the second section we apply this theory to a specific example proximate to the reference environment for the Fuel Cycle Study in New Mexico in order to provide a numerical measure of the magnitude of the costs

  18. Natural resource damage assessment

    International Nuclear Information System (INIS)

    Seddelmeyer, J.

    1991-01-01

    The assessment and collection of natural resource damages from petroleum and chemical companies unfortunate enough to have injured publicly owned natural resources is perhaps the most rapidly expanding area of environmental liability. The idea of recovering for injury to publicly owned natural resources is an extension of traditional common law tort concepts under which a person who negligently injures another or his property is called upon to compensate the injured party. Normally, once liability has been established, it is a fairly straightforward matter to calculate the various elements of loss, such as the cost to repair or replace damaged property, or medical expenses, and lost income. More difficult questions, such as the amount to be awarded for pain and suffering or emotional distress, are left to the jury, although courts limit the circumstances in which the jury is permitted to award such damages

  19. Terrorism and nuclear damage coverage

    International Nuclear Information System (INIS)

    Horbach, N. L. J. T.; Brown, O. F.; Vanden Borre, T.

    2004-01-01

    This paper deals with nuclear terrorism and the manner in which nuclear operators can insure themselves against it, based on the international nuclear liability conventions. It concludes that terrorism is currently not covered under the treaty exoneration provisions on 'war-like events' based on an analysis of the concept on 'terrorism' and travaux preparatoires. Consequently, operators remain liable for nuclear damage resulting from terrorist acts, for which mandatory insurance is applicable. Since nuclear insurance industry looks at excluding such insurance coverage from their policies in the near future, this article aims to suggest alternative means for insurance, in order to ensure adequate compensation for innocent victims. The September 11, 2001 attacks at the World Trade Center in New York City and the Pentagon in Washington, DC resulted in the largest loss in the history of insurance, inevitably leading to concerns about nuclear damage coverage, should future such assaults target a nuclear power plant or other nuclear installation. Since the attacks, some insurers have signalled their intentions to exclude coverage for terrorism from their nuclear liability and property insurance policies. Other insurers are maintaining coverage for terrorism, but are establishing aggregate limits or sublimits and are increasing premiums. Additional changes by insurers are likely to occur. Highlighted by the September 11th events, and most recently by those in Madrid on 11 March 2004, are questions about how to define acts of terrorism and the extent to which such are covered under the international nuclear liability conventions and various domestic nuclear liability laws. Of particular concern to insurers is the possibility of coordinated simultaneous attacks on multiple nuclear facilities. This paper provides a survey of the issues, and recommendations for future clarifications and coverage options.(author)

  20. (De)coupled zircon metamictization, radiation damage, and He diffusivity

    Science.gov (United States)

    Ault, A. K.; Guenthner, W.; Reiners, P. W.; Moser, A. C.; Miller, G. H.; Refsnider, K. A.

    2017-12-01

    yield uniform 25 Ma zircon He dates over 1800 ppm eU. We apply simple thermal history models that account for the coevolution of zircon radiation damage and He-diffusivity to demonstrate that visible zircon metamictization and He diffusivity can be either coupled or decoupled depending on a sample's thermal history.

  1. Radiation Damage Monitoring in the ATLAS Pixel Detector

    CERN Document Server

    Seidel, S

    2013-01-01

    We describe the implementation of radiation damage monitoring using measurement of leakage current in the ATLAS silicon pixel sensors. The dependence of the leakage current upon the integrated luminosity is presented. The measurement of the radiation damage corresponding to integrated luminosity 5.6 fb$^{-1}$ is presented along with a comparison to the theoretical model.

  2. Numerical and Experimental Validation of a New Damage Initiation Criterion

    NARCIS (Netherlands)

    Sadhinoch, M.; Atzema, E.H.; Perdahcioglu, E.S.; Van Den Boogaard, A.H.

    2017-01-01

    Most commercial finite element software packages, like Abaqus, have a built-in coupled damage model where a damage evolution needs to be defined in terms of a single fracture energy value for all stress states. The Johnson-Cook criterion has been modified to be Lode parameter dependent and this

  3. PULMONARY AND LIVER DAMAGE DURING TREATMENT WITH ACETAMINOPHEN (PARACETAMOL

    Directory of Open Access Journals (Sweden)

    L. I. Dvoretski

    2016-01-01

    Full Text Available This is a case report of pulmonary damage in the form of intestinal pneumonitis with severe respiratory failure during administration of acetaminophen (paracetamol. In addition, significant increase of ALT and AST levels without clinical signs of liver damage was observed in this patient. After glucocorticoids administration regression of radiological abnormal findings in the lungs along with normalization of liver enzymes values were registered. The rarity of interstitial pneumonitis induced by acetaminophen (paracetamol, especially in combination with liver damage, is emphasized. The presented patient history is the first case report of drug-induced hepatopulmonary syndrome during acetaminophen (paracetamol administration.

  4. Tooth-germ damage by ionizing radiation

    International Nuclear Information System (INIS)

    Sobkowiak, E.M.; Beetke, E.; Bienengraeber, V.; Held, M.; Kittner, K.H.

    1977-01-01

    Experiments on animals (four-week-old dogs) were conducted in an investigation made to study the possibility of dose-dependent tooth-germ damage produced by ionizing radiation. The individual doses were 50 R and 200 R, respectively, and they were administered once to three times at weekly intervals. Hyperemia and edemata could be observed on tooth-germ pulps from 150 R onward. Both of these conditions became more acute as the radiation dose increased (from 150 R to 600 R). Possible damage to both the dentin and enamel is pointed out. (author)

  5. mapDamage

    DEFF Research Database (Denmark)

    Ginolhac, Aurélien; Rasmussen, Morten; Gilbert, Tom

    2011-01-01

    Ancient DNA extracts consist of a mixture of contaminant DNA molecules, most often originating from environmental microbes, and endogenous fragments exhibiting substantial levels of DNA damage. The latter introduce specific nucleotide misincorporations and DNA fragmentation signatures in sequenci...... of the SAMtools suite and R environment and has been validated on both GNU/Linux and MacOSX operating systems....

  6. Core damage risk indicators

    International Nuclear Information System (INIS)

    Szikszai, T.

    1994-01-01

    The purpose of this document is to show a method for the fast recalculation of the PSA. To avoid the information loose, it is necessary to simplify the PSA models, or at least reorganize them. The method, introduced in this document, require that preparation, so we try to show, how to do that. This document is an introduction. This is the starting point of the work related to the development of the risk indicators. In the future, with the application of this method, we are going to show an everyday use of the PSA results to produce the indicators of the core damage risk. There are two different indicators of the plant safety performance, related to the core damage risk. The first is the core damage frequency indicator (CDFI), and the second is the core damage probability indicator (CDPI). Of course, we cannot describe all of the possible ways to use these indicators, rather we will try to introduce the requirements to establish such an indicator system and the calculation process

  7. Risk of nuclear damage

    International Nuclear Information System (INIS)

    Kienzl, K.

    1997-01-01

    Following the opening and words of welcome by Mr. Fritz Unterpertinger (unit director at the Austrian Federal Ministry for the Environment, Youth and Family; BMUJF) Mrs Helga Kromp-Kolb (professor at the Institute for Meteorology and Physics of the University of Natural Resources Science Vienna) illustrated the risks of nuclear damage in Europe by means of a nuclear risk map. She explained that even from a scientific or technical point of view the assessment of risks arising from nuclear power stations was fraught with great uncertainties. Estimates about in how far MCAs (maximum credible accident) could still be controlled by safety systems vary widely and so do assessments of the probability of a core melt. But there is wide agreement in all risk assessments conducted so far that MCAs might occur within a - from a human point of view - conceivable number of years. In this connection one has to bear in mind that the occurrence of such a major accident - whatever its probability may be - could entail immense damage and the question arises whether or not it is at all justifiable to expose the general public to such a risk. Klaus Rennings (Centre for European Economic Research, Mannheim, Germany) dealt with the economic aspects of nuclear risk assessment. He explained that there are already a number of studies available aiming to assess the risk of damage resulting from a core melt accident in economic terms. As to the probability of occurrence estimates vary widely between one incident in 3,333 and 250,000 year of reactor operation. It is assumed, however, that a nuclear accident involving a core melt in Germany would probably exceed the damage caused by the Chernobyl accident. The following speakers addressed the legal aspects of risks associated with nuclear installations. Mrs Monika Gimpel-Hinteregger (professor at the Institute for Civil Law in Graz) gave an overview on the applicable Austrian law concerning third party liability in the field of nuclear energy

  8. Path Dependency

    OpenAIRE

    Mark Setterfield

    2015-01-01

    Path dependency is defined, and three different specific concepts of path dependency – cumulative causation, lock in, and hysteresis – are analyzed. The relationships between path dependency and equilibrium, and path dependency and fundamental uncertainty are also discussed. Finally, a typology of dynamical systems is developed to clarify these relationships.

  9. Report on damaged FLIP TRIGA fuel

    International Nuclear Information System (INIS)

    Feltz, Donald E.; Randall, John D.; Schumacher, Robert F.

    1977-01-01

    Damaged FLIP elements were discovered, positioned adjacent to the transient rod. It then became apparent that this was not the failure of a defective, element but a heretofore unknown operating or design problem. The damaged elements are described as having bulges in the cladding and unevenly spaced dark rings along the fuelled portion of the element. Possible causes are investigated, including: defective fuel elements, incorrectly calculated power distributions in the core and in the elements, water leakage into the void follower of the transient rod, and improper safety limit for FLIP fuel. Based on measurements and calculations that have been experimentally verified it is concluded that the safety limit was not exceeded or even closely approached. It is also concluded that the problem is due entirely due to some phenomena occurring during pulsing, and that the steady state history of the fuel is not a factor

  10. Impact of genomic damage and ageing on stem cell function

    Science.gov (United States)

    Behrens, Axel; van Deursen, Jan M.; Rudolph, K. Lenhard; Schumacher, Björn

    2014-01-01

    Impairment of stem cell function contributes to the progressive deterioration of tissue maintenance and repair with ageing. Evidence is mounting that age-dependent accumulation of DNA damage in both stem cells and cells that comprise the stem cell microenvironment are partly responsible for stem cell dysfunction with ageing. Here, we review the impact of the various types of DNA damage that accumulate with ageing on stem cell functionality, as well as the development of cancer. We discuss DNA-damage-induced cell intrinsic and extrinsic alterations that influence these processes, and review recent advances in understanding systemic adjustments to DNA damage and how they affect stem cells. PMID:24576896

  11. SIRT participates at DNA damage response

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Mi Yong; Joeng, Jae Min; Lee, Kee Ho [Korea Cancer Center Hospital, Seoul (Korea, Republic of); Park, Gil Hong [College of Medicine, Korea University, Seoul (Korea, Republic of)

    2009-05-15

    Sir2 maintains genomic stability in multiple ways in yeast. As a NAD{sup +}-dependent histone deacetylase, Sir2 has been reported to control chromatin silencing. In both budding yeast and Drosophila, overexpression of Sir2 extends life span. Previous reports have also demonstrated that Sir2 participate at DNA damage repair. A protein complex containing Sir2 has been reported to translocate to DNA double-strand breaks. Following DNA damage response, SIRT1 deacetylates p53 protein and attenuates its ability as a transcription factor. Consequently, SIRT1 over-expression increases cell survival under DNA damage inducing conditions. These previous observations mean a possibility that signals generated during the process of DNA repair are delivered through SIRT1 to acetylated p53. We present herein functional evidence for the involvement of SIRT1 in DNA repair response to radiation. In addition, this modulation of DNA repair activity may be connected to deacetylation of MRN proteins.

  12. An economic approach to 'losses and damages'

    International Nuclear Information System (INIS)

    Roulleau, Thomas

    2015-01-01

    Given ever more greenhouse gas emissions, developing countries have recently placed the issue of 'losses and damages' on the bargaining table. The losses and damages ensuing from climate catastrophes depend on factors that are both planetary (extreme meteorological phenomena wherein climate change is a factor) and domestic (the exposure and vulnerability of populations). The Warsaw International Mechanism for Loss and Damage Associated with Climate Change Impacts was set up in 2013. Several developing countries are demanding that it become autonomous with its own funding. This demand does not seem justified scientifically or economically in the current context. Although economic losses owing to climate-related catastrophes have increased in recent decades, they are, as scientific studies have shown, due to increases in wealth and in the population's exposure and not to climate change as such. Furthermore, the aforementioned funding mechanism risks impeding efficient domestic actions for reducing a country's vulnerability and its population's exposure to climate-related risks

  13. Creep fatigue damage under multiaxial conditions

    International Nuclear Information System (INIS)

    Lobitz, D.W.; Nickell, R.E.

    1977-01-01

    When structural components are subjected to severe cyclic loading conditions with intermittent periods of sustained loading at elevated temperature, the designer must guard against a failure mode caused by the interaction of time-dependent and time-independent deformation. This phenomena is referred to as creep-fatigue interaction. The most elementary form of interaction theory (called linear damage summation) is now embodied in the ASME Boiler and Pressure Vessel Code. In recent years, a competitor for the linear damage summation theory has emerged, called strainrange partitioning. This procedure is based upon the visualization of the cyclic strain in a uniaxial creep-fatigue test as a hysteresis loop, with the inelastic strains in the loop counter-balanced in one of two ways. The two theories are compared and contrasted in terms of ease of use, possible inconsistencies, and component life prediction. Future work to further test the damage theories is recommended

  14. Delayed chromosomal instability induced by DNA damage

    International Nuclear Information System (INIS)

    Morgan, W.F.; Marder, B.A.; Day, J.P.

    1994-01-01

    Cellular exposure to DNA damaging agents rapidly results in a dose dependent increase in chromosomal breakage and gross structural chromosomal rearrangements. Over recent years, evidence has been accumulating indicating genomic instability can manifest multiple generations after cellular exposure to physical and chemical DNA damaging agents. Genomic instability manifests in the progeny of surviving cells, and has been implicated in mutation, gene application, cellular transformation, and cell killing. To investigate chromosome instability following DNA damage, we have used fluorescence in situ hybridization to detect chromosomal rearrangements in a human/hamster somatic hybrid cell line following exposure to ionizing radiation. Delayed chromosomal instability was detected when multiple populations of uniquely arranged metaphases were observed in clonal isolates raised from single cells surviving X-irradiation many generations after exposure. At higher radiation doses, chromosomal instability was observed in a relatively high frequency of surviving clones and, in general, those clones showed delayed chromosome instability also showed reduced survival as measured by colony forming ability

  15. Microstructural modeling of Vienne granite damage

    International Nuclear Information System (INIS)

    Homand, F.; Hoxha, D.

    2002-01-01

    The microstructural approach in damage modeling, which is presented in this paper describes the evolution of micro-crack geometry as a function of history loading. If the crack geometry is known, the effective properties could then be calculated foe any cracked rock by the mean of a micro-mechanical model. The P L evolution law which is necessary in the describing of crack geometry evolution is hardly based on the crack microscope observation as well as on the theory of fabric tensors. This approach is applied in the modeling of mechanical behaviour of Vienne granite. The result of model simulations are compared with laboratory tests. (author)

  16. Possibilities of heart damage during roentgenotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Karczewska, Z; Modrzejewski, W; Filipowska, D; Kalicinski, A [Akademia Medyczna, Bialystok (Poland); Szpital Wojewodzki, Bialystok [Poland

    1976-10-11

    The authors examined 39 women treated with roentgenotherapy for breast cancer in a total dose of 5100 r. The electrocardiographic pattern at rest and after exercise (Master's test), AspAT and AIAT activity were evaluated, and detailed history was obtained with particular reference to anginal pains. The investigations were carried out before and after roentgenotherapy and it was shown that radiotherapy caused myocardial and ischaemic damage. Attention is called to the necessity of accurate selection of field for radiotherapy to protect the heart against radiation.

  17. History of Bioterrorism: Botulism

    Medline Plus

    Full Text Available ... is Doing Blog: Public Health Matters Video: "The History of Bioterrorism" Recommend on Facebook Tweet Share Compartir ... as bioterrorist weapons. Watch the Complete Program "The History of Bioterroism" (26 min 38 sec) Watch Specific ...

  18. History of Bioterrorism: Botulism

    Science.gov (United States)

    ... is Doing Blog: Public Health Matters Video: "The History of Bioterrorism" Recommend on Facebook Tweet Share Compartir ... as bioterrorist weapons. Watch the Complete Program "The History of Bioterroism" (26 min 38 sec) Watch Specific ...

  19. "Hillary - en god historie"

    DEFF Research Database (Denmark)

    Bjerre, Thomas Ærvold

    2007-01-01

    Anmeldelse af Carl Bernsteins Hillary Rodham Clinton og Michael Ehrenreichs Hillary - En amerikansk historie Udgivelsesdato: 15. november......Anmeldelse af Carl Bernsteins Hillary Rodham Clinton og Michael Ehrenreichs Hillary - En amerikansk historie Udgivelsesdato: 15. november...

  20. Carbon Nanofiber Cement Sensors to Detect Strain and Damage of Concrete Specimens Under Compression.

    Science.gov (United States)

    Galao, Oscar; Baeza, F Javier; Zornoza, Emilio; Garcés, Pedro

    2017-11-24

    Cement composites with nano-additions have been vastly studied for their functional applications, such as strain and damage sensing. The capacity of a carbon nanofiber (CNF) cement paste has already been tested. However, this study is focused on the use of CNF cement composites as sensors in regular concrete samples. Different measuring techniques and humidity conditions of CNF samples were tested to optimize the strain and damage sensing of this material. In the strain sensing tests (for compressive stresses up to 10 MPa), the response depends on the maximum stress applied. The material was more sensitive at higher loads. Furthermore, the actual load time history did not influence the electrical response, and similar curves were obtained for different test configurations. On the other hand, damage sensing tests proved the capability of CNF cement composites to measure the strain level of concrete samples, even for loads close to the material's strength. Some problems were detected in the strain transmission between sensor and concrete specimens, which will require specific calibration of each sensor one attached to the structure.

  1. Immunoassay of DNA damage

    International Nuclear Information System (INIS)

    Gasparro, F.P.; Santella, R.M.

    1988-01-01

    The direct photomodification of DNA by ultraviolet light or the photo-induced addition of exogenous compounds to DNA components results in alterations of DNA structure ranging from subtle to profound. There are two consequences of these conformational changes. First, cells in which the DNA has been damaged are capable of executing repair steps. Second, the DNA which is usually of very low immunogenicity now becomes highly antigenic. This latter property has allowed the production of a series of monoclonal antibodies that recognize photo-induced DNA damage. Monoclonal antibodies have been generated that recognize the 4',5'-monoadduct and the crosslink of 8-methoxypsoralen in DNA. In addition, another antibody has been prepared which recognizes the furan-side monoadduct of 6,4,4'-trimethylangelicin in DNA. These monoclonal antibodies have been characterized as to sensitivity and specificity using non-competitive and competitive enzyme-linked-immunosorbent assays (ELISA). (author)

  2. Neutron induced radiation damage

    International Nuclear Information System (INIS)

    Williams, M.M.R.

    1977-01-01

    We derive a general expression for the number of displaced atoms of type j caused by a primary knock-on of type i. The Kinchin-Pease model is used, but considerably generalised to allow for realistic atomic potentials. Two cases are considered in detail: the single particle problem causing a cascade and the neutron initiated problem which leads to multiple subcascades. Numerical results have been obtained for a variety of scattering laws. An important conclusion is that neutron initiated damage is much more severe than atom-initiated damage and leads to the number of displaced atoms being a factor of (A+1) 2 /4A larger than the single primary knock-on theory predicts. A is the ratio of the atomic mass to the neutron mass. The importance of this result to the theory of neutron sputtering is explained. (orig.) [de

  3. Immunoassay of DNA damage

    Energy Technology Data Exchange (ETDEWEB)

    Gasparro, F P; Santella, R M

    1988-09-01

    The direct photomodification of DNA by ultraviolet light or the photo-induced addition of exogenous compounds to DNA components results in alterations of DNA structure ranging from subtle to profound. There are two consequences of these conformational changes. First, cells in which the DNA has been damaged are capable of executing repair steps. Second, the DNA which is usually of very low immunogenicity now becomes highly antigenic. This latter property has allowed the production of a series of monoclonal antibodies that recognize photo-induced DNA damage. Monoclonal antibodies have been generated that recognize the 4',5'-monoadduct and the crosslink of 8-methoxypsoralen in DNA. In addition, another antibody has been prepared which recognizes the furan-side monoadduct of 6,4,4'-trimethylangelicin in DNA. These monoclonal antibodies have been characterized as to sensitivity and specificity using non-competitive and competitive enzyme-linked-immunosorbent assays (ELISA).

  4. Radiation damage in DNA

    International Nuclear Information System (INIS)

    Lafleur, V.

    1978-01-01

    A number of experiments are described with the purpose to obtain a better insight in the chemical nature and the biological significance of radiation-induced damage in DNA, with some emphasis on the significance of alkali-labile sites. It is shown that not only reactions of OH radicals but also of H radicals introduce breaks and other inactivating damage in single-standed phiX174 DNA. It is found that phosphate buffer is very suitable for the study of the reactions of H radicals with DNA, as the H 2 PO 4 - ions convert the hydrated electrons into H radicals. The hydrated electron, which does react with DNA, does not cause a detectable inactivation. (Auth.)

  5. Canadian petroleum history bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Cass, D.

    2003-09-27

    The Petroleum History Bibliography includes a list of more than 2,000 publications that record the history of the Canadian petroleum industry. The list includes books, theses, films, audio tapes, published articles, company histories, biographies, autobiographies, fiction, poetry, humour, and an author index. It was created over a period of several years to help with projects at the Petroleum History Society. It is an ongoing piece of work, and as such, invites comments and additions.

  6. Timing fire to minimize damage in managing oak ecosystems

    Science.gov (United States)

    Daniel C. Dey; Callie Jo Schweitzer

    2015-01-01

    The long history of fire in North America spans millennia and is recognized as an important driver in the widespread and long-term dominance of oak species. Early European settlers intensified the occurrence of fire from about 1850 to 1950, with dates varying by region. This resulted in much forest damage and gained fire a negative reputation. The lack of fire for the...

  7. Temporary patching of damaged UF{sub 6} cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Cardenas, A.L. [Martin Marietta Energy Systems, Inc., OH (United States)

    1991-12-31

    Patching techniques based on application of epoxy resins have been developed for temporarily repairing UF{sub 6} cylinders which have sustained relatively minor damage and must be safely emptied. The method is considerably faster and simpler than metallurgical weld repairs. Laboratory tests, detailed operational procedures, and case histories of experience at the Portsmouth Gaseous Diffusion Plant are described.

  8. Cavitation damage of ceramics

    International Nuclear Information System (INIS)

    Kovalenko, V.I.; Marinin, V.G.

    1988-01-01

    Consideration is given to results of investigation of ceramic material damage under the effect of cavitation field on their surface, formed in water under the face of exponential concentrator, connected with ultrasonic generator UZY-3-0.4. Amplitude of vibrations of concentrator face (30+-2)x10 -6 m, frequency-21 kHz. It was established that ceramics resistance to cavitation effect correlated with the product of critical of stress intensity factor and material hardness

  9. Nondestructive damage detection and evaluation technique for seismically damaged structures

    Science.gov (United States)

    Adachi, Yukio; Unjoh, Shigeki; Kondoh, Masuo; Ohsumi, Michio

    1999-02-01

    The development of quantitative damage detection and evaluation technique, and damage detection technique for invisible damages of structures are required according to the lessons from the 1995 Hyogo-ken Nanbu earthquake. In this study, two quantitative damage sensing techniques for highway bridge structures are proposed. One method is to measure the change of vibration characteristics of the bridge structure. According to the damage detection test for damaged bridge column by shaking table test, this method can successfully detect the vibration characteristic change caused by damage progress due to increment excitations. The other method is to use self-diagnosis intelligent materials. According to the reinforced concrete beam specimen test, the second method can detect the damage by rupture of intelligent sensors, such as optical fiber or carbon fiber reinforced plastic rod.

  10. Diet History Questionnaire: Database Revision History

    Science.gov (United States)

    The following details all additions and revisions made to the DHQ nutrient and food database. This revision history is provided as a reference for investigators who may have performed analyses with a previous release of the database.

  11. History of Science and History of Philologies.

    Science.gov (United States)

    Daston, Lorraine; Most, Glenn W

    2015-06-01

    While both the sciences and the humanities, as currently defined, may be too heterogeneous to be encompassed within a unified historical framework, there is good reason to believe that the history of science and the history of philologies both have much to gain by joining forces. This collaboration has already yielded striking results in the case of the history of science and humanist learning in early modern Europe. This essay argues that first, philology and at least some of the sciences (e.g., astronomy) remained intertwined in consequential ways well into the modern period in Western cultures; and second, widening the scope of inquiry to include other philological traditions in non-Western cultures offers rich possibilities for a comparative history of learned practices. The focus on practices is key; by shifting the emphasis from what is studied to how it is studied, deep commonalities emerge among disciplines--and intellectual traditions--now classified as disparate.

  12. Modern History of Tibet

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Authored by Xu Guangzhi, this book is a subsidiary project of Research Into Traditional Culture and History (of the PRC Ministry of Education) conducted by China Tibetology Research Institute of Tibet University. The book combines modern history of Tibet with modern history of China as a whole. It tells the close ties between various members of the Chinese nation.

  13. History of Particle Physics

    Science.gov (United States)

    back to history page Back Particle Physics Timeline For over two thousand years people have thought the Standard Model. We invite you to explore this history of particle physics with a focus on the : Quantum Theory 1964 - Present: The Modern View (the Standard Model) back to history page Back Sections of

  14. Teaching Women's History.

    Science.gov (United States)

    Fain, George

    1995-01-01

    Argues that women's history should stress the broad sociological view of women's roles not only in politics but in mundane, day-to-day life throughout all of history, rather that reducing women's history to a few token figures. Notes that many college and secondary texts and testing materials have recognized the trend toward the inclusion of…

  15. Towards Household History

    NARCIS (Netherlands)

    van Rappard, J.F.H.

    1998-01-01

    It is maintained that in contradistinction to the natural sciences, in psychology (and other human sciences) ‘history is not past tense’. This is borne out by the contemporary relevance of a specific part of the history of psychology, which focuses on the internal-theoretical significance of history

  16. Film and History.

    Science.gov (United States)

    Schaber, Robin L.

    2002-01-01

    Provides an annotated bibliography of Web sites that focus on using film to teach history. Includes Web sites in five areas: (1) film and education; (2) history of cinema; (3) film and history resources; (4) film and women; and (5) film organizations. (CMK)

  17. Integrity Analysis of Damaged Steam Generator Tubes

    International Nuclear Information System (INIS)

    Stanic, D.

    1998-01-01

    Variety of degradation mechanisms affecting steam generator tubes makes steam generators as one of the critical components in the nuclear power plants. Depending of their nature, degradation mechanisms cause different types of damages. It requires performance of extensive integrity analysis in order to access various conditions of crack behavior under operating and accidental conditions. Development and application of advanced eddy current techniques for steam generator examination provide good characterization of found damages. Damage characteristics (shape, orientation and dimensions) may be defined and used for further evaluation of damage influence on tube integrity. In comparison with experimental and analytical methods, numerical methods are also efficient tools for integrity assessment. Application of finite element methods provides relatively simple modeling of different type of damages and simulation of various operating conditions. The stress and strain analysis may be performed for elastic and elasto-plastic state with good ability for visual presentation of results. Furthermore, the fracture mechanics parameters may be calculated. Results obtained by numerical analysis supplemented with experimental results are the base for definition of alternative plugging criteria which may significantly reduce the number of plugged tubes. (author)

  18. Numerical and Experimental Validation of a New Damage Initiation Criterion

    Science.gov (United States)

    Sadhinoch, M.; Atzema, E. H.; Perdahcioglu, E. S.; van den Boogaard, A. H.

    2017-09-01

    Most commercial finite element software packages, like Abaqus, have a built-in coupled damage model where a damage evolution needs to be defined in terms of a single fracture energy value for all stress states. The Johnson-Cook criterion has been modified to be Lode parameter dependent and this Modified Johnson-Cook (MJC) criterion is used as a Damage Initiation Surface (DIS) in combination with the built-in Abaqus ductile damage model. An exponential damage evolution law has been used with a single fracture energy value. Ultimately, the simulated force-displacement curves are compared with experiments to validate the MJC criterion. 7 out of 9 fracture experiments were predicted accurately. The limitations and accuracy of the failure predictions of the newly developed damage initiation criterion will be discussed shortly.

  19. Residential damage in an area of underground coal mining

    International Nuclear Information System (INIS)

    Padgett, M.F.

    1988-01-01

    In order to estimate the potential for future subsidence-related residential damage, a statistical analysis of past residential damage in the Boulder-Weld, Colorado, coal field was performed. The objectives of this study were to assess the difference in damage severity and frequency between undermined and non-undermined areas, and to determine, where applicable, which mining factors significantly influence the severity and frequency of residential damage. The results of this study suggest that undermined homes have almost three times the risk of having some type of structural damage than do non-undermined homes. The study also indicated that both geologic factors, such as the ratio of sandstone/claystone in the overburden, and mining factors, such as the mining feature (room, pillar, entry, etc.), can significantly affect the severity of overlying residential damage. However, the results of this study are dependent on local conditions and should not be applied elsewhere unless the geologic, mining, and residential conditions are similar

  20. Damage-induced nonassociated inelastic flow in rock salt

    International Nuclear Information System (INIS)

    Chan, K.S.; Bodner, S.R.; Brodsky, N.S.; Fossum, A.F.; Munson, D.E.

    1993-01-01

    The multi-mechanism deformation coupled fracture model recently developed by CHAN, et al. (1992), for describing time-dependent, pressure-sensitive inelastic flow and damage evolution in crystalline solids was evaluated against triaxial creep experiments on rock salt. Guided by experimental observations, the kinetic equation and the flow law for damage-induced inelastic flow in the model were modified to account for the development of damage and inelastic dilatation in the transient creep regime. The revised model was then utilized to obtain the creep response and damage evolution in rock salt as a function of confining pressure and stress difference. Comparison between model calculation and experiment revealed that damage-induced inelastic flow is nonassociated, dilatational, and contributes significantly to the macroscopic strain rate observed in rock salt deformed at low confining pressures. The inelastic strain rate and volumetric strain due to damage decrease with increasing confining pressures, and all are suppressed at sufficiently high confining pressures

  1. Lattice damage in ion-implanted silicon-germanium alloys

    International Nuclear Information System (INIS)

    Haynes, T.E.; Holland, O.W.

    1992-08-01

    The damage produced in Si 1-x Ge x alloys (0≤x≤1) by implantation of 70--100 keV 30 Si + has been measured as a function of temperature and fluence by ion channeling. For all compositions, the damage efficiency decreased sharply as the implant temperature was increased between room temperature and 150 degrees C. Furthermore, the damage efficiency in alloys of intermediate compositions (0.34≤x≤0.5) exceeds that in Ge, especially at elevated temperatures, despite the larger cascade energy density in Ge. It is shown that this behavior can be described based on a model in which the point-defect mobility is the dominant factor controlling damage retention, rather than the cascade energy density. This approach provides a framework for understanding other temperature-dependent phenomena related to damage growth in Si-Ge alloys including dose-rate effects and damage saturation in MeV implantation

  2. History of mathematics and history of science

    OpenAIRE

    Mann, Tony

    2011-01-01

    This essay argues that the diversity of the history of mathematics community in the United Kingdom has influenced the development of the subject and is a significant factor behind the different concerns often evident in work on the history of mathematics when compared with that of historians of science. The heterogeneous nature of the community, which includes many who are not specialist historians, and the limited opportunities for academic\\ud careers open to practitioners have had a profoun...

  3. Creep damage index as a sensitive indicator of damage accumulation in thermoplastic laminates

    Czech Academy of Sciences Publication Activity Database

    Minster, Jiří; Šperl, Martin; Šepitka, J.

    2018-01-01

    Roč. 37, č. 3 (2018), s. 147-154 ISSN 0731-6844 Institutional support: RVO:68378297 Keywords : damage accumulation * thermoplastic laminate * cyclic tensile loading * time-dependent properties * microindentation Subject RIV: JL - Materials Fatigue, Friction Mechanics OBOR OECD: Audio engineering, reliability analysis Impact factor: 1.086, year: 2016 http://journals.sagepub.com/doi/pdf/10.1177/0731684417735184

  4. Hypertensive target organ damage in Ghanaian civil servants with hypertension.

    Directory of Open Access Journals (Sweden)

    Juliet Addo

    2009-08-01

    Full Text Available Low levels of detection, treatment and control of hypertension have repeatedly been reported from sub Saharan Africa, potentially increasing the likelihood of target organ damage.A cross-sectional study was conducted on 1015 urban civil servants aged > or = 25 years from seven central government ministries in Accra, Ghana. Participants diagnosed to have hypertension were examined for target organ involvement. Hypertensive target organ damage was defined as the detection of any of the following: left ventricular hypertrophy diagnosed by electrocardiogram, reduction in glomerular filtration rate, the presence of hypertensive retinopathy or a history of a stroke.Of the 219 hypertensive participants examined, 104 (47.5% had evidence of target organ damage. The presence of target organ damage was associated with higher systolic and diastolic blood pressure levels. The odds of developing hypertensive target organ damage was five to six times higher in participants with blood pressure (BP > or = 180/110 mmHg compared to those with BP < 140/90 mmHg, and there was a trend to higher odds of target organ damage with increasing BP (p = 0.001. Women had about lower odds of developing target organ damage compared to men.The high prevalence of target organ damage in this working population associated with increasing blood pressure, emphasises the need for hypertension control programs aimed at improving the detection of hypertension, and importantly addressing the issues inhibiting the effective treatment and control of people with hypertension in the population.

  5. Ion-induced damage and amorphization in Si

    International Nuclear Information System (INIS)

    Holland, O.W.; White, C.W.

    1990-01-01

    Ion-induced damage growth in high-energy, self-ion irradiated Si was studied using electron microscopy and Rutherford backscattering spectroscopy. The results show that there is a marked variation in the rate of damage growth, as well as the damage morphology, along the path of the ion. Near the ion end-of-range (eor), damage increases monotonically with ion fluence until a buried amorphous layer is formed, while damage growth saturates at a low level in the region ahead. The morphology of the damage in the saturated region is shown to consist predominantly of simple defect clusters such as the divacancy. Damage growth remains saturated ahead of the eor until expansion of the buried amorphous layer encroaches into the region. A homogeneous growth model is presented which accounts for damage saturation, and accurately predicts the dose-rate dependence of the saturation level. Modifications of the model are discussed which are needed to account for the rapid growth in the eor region and near the interface of the buried amorphous layer. Two important factors contributing to rapid damage growth are identified. Spatial separation of the Frenkel defect pairs (i.e. interstitials and vacancies) due to the momentum of the interstitials is shown to greatly impact damage growth near the eor, while uniaxial strain in the interfacial region of the amorphous layer is identified as an important factor contributing to growth at that location. 20 refs., 10 figs

  6. Computer simulations of radiation damage in protein crystals

    International Nuclear Information System (INIS)

    Zehnder, M.

    2007-03-01

    The achievable resolution and the quality of the dataset of an intensity data collection for structure analysis of protein crystals with X-rays is limited among other factors by radiation damage. The aim of this work is to obtain a better quantitative understanding of the radiation damage process in proteins. Since radiation damage is unavoidable it was intended to look for the optimum ratio between elastically scattered intensity and radiation damage. Using a Monte Carlo algorithm physical processes after an inelastic photon interaction are studied. The main radiation damage consists of ionizations of the atoms through the electron cascade following any inelastic photon interaction. Results of the method introduced in this investigation and results of an earlier theoretical studies of the influence of Auger-electron transport in diamond are in a good agreement. The dependence of the radiation damage as a function of the energy of the incident photon was studied by computer-aided simulations. The optimum energy range for diffraction experiments on the protein myoglobin is 10-40 keV. Studies of radiation damage as a function of crystal volume and shape revealed that very small plate or rod shaped crystals suffer less damage than crystals formed like a cube with the same volume. Furthermore the influence of a few heavy atoms in the protein molecule on radiation damage was examined. Already two iron atoms in the unit cell of myoglobin increase radiation damage significantly. (orig.)

  7. World History Workshop (1983).

    Science.gov (United States)

    1984-10-01

    history appeared tenuous. While the study of American history was viewed as necessary to "indoctrinate kids ," world history is unable to make such a...world" which is hard to avoid in world history, where one examines China in 1500, China in 1800, and so on. A pedagogical goal in the new course was to...the historian to make intelligent decisions about what information he is going to talk about. Viewing world history as a scenario also has a pedagogic

  8. Life history types and strategies

    DEFF Research Database (Denmark)

    Boel, Mikkel

    strategies and types in migratory freshwater fish, using brown trout and alewife as study organisms. Firstly, we investigated underlying mechanisms of resident and migratory life history strategies of salmonids, using indicators for nutritional status, stress, tissue damage and smoltification. Secondly...... III the minimum predation from cormorants and herons was estimated over a three year period on the brown trout population of of Lake Hald. The magnitude of the predation pressure from both bird species were very similar and when summed up, the avian predation accounted for an average minimum of 37.......2 % of the annual brown trout mortality in the lake and 10.1 % in the tributaries. This result illustrates that avian predation in the lake can be quite substantial and potentially plays an important role in the population dynamics of brown trout. Cormorants alone were responsible 21.2% in the lake and the arrival...

  9. Suicidal Behavior in Chemically Dependent Adolescents.

    Science.gov (United States)

    Cavaiola, Alan A.; Lavender, Neil

    1999-01-01

    Study explores distinctions between chemically dependent suicide attempters, chemically dependent nonsuicidal adolescents, and high school students with no history of chemical dependency (N=250). Results reveal that there were significant differences between the chemically dependent groups. It was also found that the majority of suicidal gestures…

  10. Military Robotics and Collateral Damage

    National Research Council Canada - National Science Library

    Kott, Robert Douglass ;Alexander

    2004-01-01

    .... Such concepts raise important questions in terms of their impact on collateral damage. In a broader context, western warfare in general places a continuously growing emphasis on issues of collateral damage...

  11. Mellem historie- og krigsvidenskab

    DEFF Research Database (Denmark)

    Hansen Schøning, Anna Sofie

    2016-01-01

    history was used to establish national and organisational identity. In the 1880s, military history was used as a means to find, explain and apply universal principles of war and, in the 1910s, military history should be used as a means to gain general insight that could potentially lead to a better......The article investigates how military history was taught as part of the Danish higher officer education from 1830 to 1920 and how the subject was affected by developments in academic history and the science of war. It argues that military history, as it was taught in the formal officer education......, could not be seen solely as a historic subject but also as a subject under the influence of the discipline of military science. Three very different understandings of how military history can contribute to higher officer education are shown through the analysis of textbooks. In the 1830s military...

  12. Three concepts of history

    Directory of Open Access Journals (Sweden)

    Antonio Campillo

    2016-05-01

    Full Text Available The aim of this article is twofold. On the one hand, I will outline the diverse usages that the concept of history has taken on throughout Western history. These different usages may be grouped together in three semantic fields (history as a way of knowing, as a way of being and as a way of doing, which correspond to three ways of understanding the Philosophy of History: as Epistemology of History, as Ontology of historicity and as ethical-political Critique of the present. On the other hand, I will show that these three concepts of history (and, accordingly, the three ways of understanding the Philosophy of History refer mutually to each other and, thus, are inseparable from each other.

  13. Contribution to the damage measurement of reinforced concrete buildings under seismic solicitations: proposal of an improvement for the evaluation of the damaging potential of a signal and of the damage for the girders structures: introduction to the reliability analysis of the damage in terms of the damaging potential of a seismic signal

    International Nuclear Information System (INIS)

    Naze, P.A.

    2004-12-01

    Building damage measurement during and after an earthquake remains an economical as well as technical stake as difficult to cope with as the problem it raises all the more because its importance depends on the field or the building function: civil, medical, military, nuclear... Even building ruin remains one of the most critical diagnosis to establish. Then since prediction of earthquake still remains impossible, foreseeing structural damages due to seismic motion has become a key point in earthquake engineering. This work aims at evaluating the relevance of classical seismic signal damaging potential indices and at proposing improvement of these indices in order to provide better prediction of structural damage due to earthquake. The first part supplies a non exhaustive state of the art of main Damaging Potential Indices IP and Damage Indices ID used in earthquake engineering. In the second part, IP/ID correlations results are analysed in order to evaluate IP relevance, to justify displacement based approach use (capacity spectrum method) for damage prediction and to make good the proposal for improvement of Damaging Potential Index. But studding seismic signal damaging potential is usually not enough to foresee damage firstly because scalar representation of damaging potential is not easy to link to physics reality and secondly because of damage scattering often observed for a single value of seismic signal damaging potential. In the same way, a single damage index value may correspond to very different structural damage states. Hence, this work carries on with a contribution to damage index reliability improvement, able to detect real structural damage appearance as well as to quantify this damage by associating the distance between one structural sate and the structural collapse, defined as an instability. (author)

  14. Radiation damage of uranium; Radijaciono ostecenje urana

    Energy Technology Data Exchange (ETDEWEB)

    Lazarevic, Dj [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

    1966-11-15

    Study of radiation damage covered the following: Kinetics of electric resistance of uranium and uranium alloy with 1% of molybdenum dependent on the second phase and burnup rate; Study of gas precipitation and diffusion of bubbles by transmission electron microscopy; Numerical analysis of the influence of defects distribution and concentration on the rare gas precipitation in uranium; study of thermal sedimentation of uranium alloy with molybdenum; diffusion of rare gas in metal by gas chromatography method.

  15. Solar History An Introduction

    CERN Document Server

    Vita-Finzi, Claudio

    2013-01-01

    Beyond the four centuries of sunspot observation and the five decades during which artificial satellites have monitored the Sun – that is to say for 99.99999% of the Sun’s existence – our knowledge of solar history depends largely on analogy with kindred main sequence stars, on the outcome of various kinds of modelling, and on indirect measures of solar activity. They include the analysis of lunar rocks and meteorites for evidence of solar flares and other components of the solar cosmic-ray (SCR) flux, and the measurement of cosmogenic isotopes in wood, stratified ice and marine sediments to evaluate changes in the galactic cosmic-ray (GCR) flux and thus infer changes in the sheltering magnetic fields of the solar wind. In addition, shifts in the global atmospheric circulation which appear to result from cyclic fluctuations in solar irradiance have left their mark in river sediments and in the isotopic composition of cave deposits. In this volume the results these sources have already produced have bee...

  16. Radiation damage in semiconductor detectors

    International Nuclear Information System (INIS)

    Kraner, H.W.

    1981-12-01

    A survey is presented of the important damage-producing interactions in semiconductor detectors and estimates of defect numbers are made for MeV protons, neutrons and electrons. Damage effects of fast neutrons in germanium gamma ray spectrometers are given in some detail. General effects in silicon detectors are discussed and damage constants and their relationship to leakage current is introduced

  17. Dependent Classes

    DEFF Research Database (Denmark)

    Gasiunas, Vaidas; Mezini, Mira; Ostermann, Klaus

    2007-01-01

    of dependent classes and a machine-checked type soundness proof in Isabelle/HOL [29], the first of this kind for a language with virtual classes and path-dependent types. [29] T.Nipkow, L.C. Poulson, and M. Wenzel. Isabelle/HOL -- A Proof Assistant for Higher-Order Logic, volume 2283 of LNCS, Springer, 2002......Virtual classes allow nested classes to be refined in subclasses. In this way nested classes can be seen as dependent abstractions of the objects of the enclosing classes. Expressing dependency via nesting, however, has two limitations: Abstractions that depend on more than one object cannot...... be modeled and a class must know all classes that depend on its objects. This paper presents dependent classes, a generalization of virtual classes that expresses similar semantics by parameterization rather than by nesting. This increases expressivity of class variations as well as the flexibility...

  18. Exercise Dependence

    Directory of Open Access Journals (Sweden)

    Erdal Vardar

    2012-06-01

    Full Text Available Exercise dependence define a condition in which a person performs excessive exercise resulting in deterioration of his or her physical and mental health wellness. Despite many clinical research studies on exercise dependence, exact diagnostic criteria has not been developed yet. Clinical evidences concerning etiology, epidemiology, underlying mechanisms and treatment of exercise dependence are still not sufficient. Moreover, evaluation of this clinical disorder within dependency perspective is a fairly new concept. Recent studies have shown that exercise dependence has similar features like chemical substance dependence with regards to withdrawal and tolerance symptoms. The aim of this review was to briefly evaluate diagnostic and clinical features of exercise dependence. [Archives Medical Review Journal 2012; 21(3.000: 163-173

  19. Tokamak ARC damage

    International Nuclear Information System (INIS)

    Murray, J.G.; Gorker, G.E.

    1985-01-01

    Tokamak fusion reactors will have large plasma currents of approximately 10 MA with hundreds of megajoules stored in the magnetic fields. When a major plasma instability occurs, the disruption of the plasma current induces voltage in the adjacent conducting structures, giving rise to large transient currents. The induced voltages may be sufficiently high to cause arcing across sector gaps or from one protruding component to another. This report reviews a tokamak arcing scenario and provides guidelines for designing tokamaks to minimize the possibility of arc damage

  20. Contextualizing aquired brain damage

    DEFF Research Database (Denmark)

    Nielsen, Charlotte Marie Bisgaard

    2014-01-01

    Contextualizing aquired brain damage Traditional approaches study ’communicational problems’ often in a discourse of disabledness or deficitness. With an ontology of communcation as something unique and a presupposed uniqueness of each one of us, how could an integrational approach (Integrational...... for people with aquired brain injuries will be presented and comparatively discussed in a traditional versus an integrational perspective. Preliminary results and considerations on ”methods” and ”participation” from this study will be presented along with an overview of the project's empirical data....

  1. Severe fuel damage projects

    International Nuclear Information System (INIS)

    Sdouz, G.

    1987-10-01

    After the descriptions of the generation of a Severe Fuel Damage Accident in a LWR the hypothetical course of such an accident is explained. Then the most significant projects are described. At each project the experimental facility, the most important results and the concluding models and codes are discussed. The selection of the projects is concentrated on the German Projekt Nukleare Sicherheit (PNS), tests performed at the Idaho National Engineering Laboratory (INEL) and smaller projects in France and Great Britain. 25 refs., 26 figs. (Author)

  2. Tokamak ARC damage

    Energy Technology Data Exchange (ETDEWEB)

    Murray, J.G.; Gorker, G.E.

    1985-01-01

    Tokamak fusion reactors will have large plasma currents of approximately 10 MA with hundreds of megajoules stored in the magnetic fields. When a major plasma instability occurs, the disruption of the plasma current induces voltage in the adjacent conducting structures, giving rise to large transient currents. The induced voltages may be sufficiently high to cause arcing across sector gaps or from one protruding component to another. This report reviews a tokamak arcing scenario and provides guidelines for designing tokamaks to minimize the possibility of arc damage.

  3. Neutron radiation damage studies on silicon detectors

    International Nuclear Information System (INIS)

    Li, Zheng; Chen, W.; Kraner, H.W.

    1990-10-01

    Effects of neutron radiation on electrical properties of Si detectors have been studied. At high neutron fluence (Φ n ≥ 10 12 n/cm 2 ), C-V characteristics of detectors with high resistivities (ρ ≥ 1 kΩ-cm) become frequency dependent. A two-trap level model describing this frequency dependent effect is proposed. Room temperature anneal of neutron damaged (at LN 2 temperature) detectors shows three anneal stages, while only two anneal stages were observed in elevated temperature anneal. 19 refs., 14 figs

  4. Laser-Induced Damage with Femtosecond Pulses

    Science.gov (United States)

    Kafka, Kyle R. P.

    The strong electric fields of focused femtosecond laser pulses lead to non-equilibrium dynamics in materials, which, beyond a threshold intensity, causes laser-induced damage (LID). Such a strongly non-linear and non-perturbative process renders important LID observables like fluence and intensity thresholds and damage morphology (crater) extremely difficult to predict quantitatively. However, femtosecond LID carries a high degree of precision, which has been exploited in various micro/nano-machining and surface engineering applications, such as human eye surgery and super-hydrophobic surfaces. This dissertation presents an array of experimental studies which have measured the damage behavior of various materials under femtosecond irradiation. Precision experiments were performed to produce extreme spatio-temporal confinement of the femtosecond laser-solid damage interaction on monocrystalline Cu, which made possible the first successful direct-benchmarking of LID simulation with realistic damage craters. A technique was developed to produce laser-induced periodic surface structures (LIPSS) in a single pulse (typically a multi-pulse phenomenon), and was used to perform a pump-probe study which revealed asynchronous LIPSS formation on copper. Combined with 1-D calculations, this new experimental result suggests more drastic electron heating than expected. Few-cycle pulses were used to study the LID performance and morphology of commercial ultra-broadband optics, which had not been systematically studied before. With extensive surface analysis, various morphologies were observed, including LIPSS, swelling (blisters), simple craters, and even ring-shaped structures, which varied depending on the coating design, number of pulses, and air/vacuum test environment. Mechanisms leading to these morphologies are discussed, many of which are ultrafast in nature. The applied damage behavior of multi-layer dielectric mirrors was measured and compared between long pulse (150 ps

  5. History of mathematics and history of science.

    Science.gov (United States)

    Mann, Tony

    2011-09-01

    This essay argues that the diversity of the history of mathematics community in the United Kingdom has influenced the development of the subject and is a significant factor behind the different concerns often evident in work on the history of mathematics when compared with that of historians of science. The heterogeneous nature of the community, which includes many who are not specialist historians, and the limited opportunities for academic careers open to practitioners have had a profound effect on the discipline, leading to a focus on elite mathematics and great mathematicians. More recently, reflecting earlier developments in the history of science, an increased interest in the context and culture of the practice of mathematics has become evident.

  6. The teaching of history through histories

    Directory of Open Access Journals (Sweden)

    María Gabriela Calvas-Ojeda

    2017-12-01

    Full Text Available The comic strips have been introduced into the world of history as a didactic resource for their learning; However, there are still shortcomings in their use by teachers, motivated on many occasions due to lack of knowledge and insufficient methodological preparation; The purpose of this work is to socialize knowledge related to these didactic resources to contribute to the didactic-methodological enrichment of the teacher, in order to change this attitude. The methodological strategy responds to the quantitative-qualitative paradigm; in the collection of the information a participant observation guide was used to the history classes and interview to a sample of 9 teachers of Third Degree of the schools of the city of Machala randomly selected. We recorded the observations of the knowledge acquired by the 98 students who received the classes mediated by comic strips, which allowed us to conclude that comics for the teaching and learning of History constitute a powerful didactic resource.

  7. Permeability of WIPP Salt During Damage Evolution and Healing

    International Nuclear Information System (INIS)

    BODNER, SOL R.; CHAN, KWAI S.; MUNSON, DARRELL E.

    1999-01-01

    The presence of damage in the form of microcracks can increase the permeability of salt. In this paper, an analytical formulation of the permeability of damaged rock salt is presented for both initially intact and porous conditions. The analysis shows that permeability is related to the connected (i.e., gas accessible) volumetric strain and porosity according to two different power-laws, which may be summed to give the overall behavior of a porous salt with damage. This relationship was incorporated into a constitutive model, known as the Multimechanism Deformation Coupled Fracture (MDCF) model, which has been formulated to describe the inelastic flow behavior of rock salt due to coupled creep, damage, and healing. The extended model was used to calculate the permeability of rock salt from the Waste Isolation Pilot Plant (WIPP) site under conditions where damage evolved with stress over a time period. Permeability changes resulting from both damage development under deviatoric stresses and damage healing under hydrostatic pressures were considered. The calculated results were compared against experimental data from the literature, which indicated that permeability in damaged intact WIPP salt depends on the magnitude of the gas accessible volumetric strain and not on the total volumetric strain. Consequently, the permeability of WIPP salt is significantly affected by the kinetics of crack closure, but shows little dependence on the kinetics of crack removal by sintering

  8. Damage characterization for particles filled semi-crystalline polymer

    Directory of Open Access Journals (Sweden)

    Lauro Franck

    2015-01-01

    Full Text Available Damage evolution and characterization in semi-crystalline polymer filled with particles under various loadings is still a challenge. A specific damage characterization method using Digital Image Correlation is proposed for a wide range of strain rates considering tensile tests with hydraulic jacks as well as Hopkinson's bars. This damage measurement is obtained by using and adapting the SEE method [1] which was developed to characterize the behaviour laws at constant strain rates of polymeric materials in dynamic. To validate the characterization process, various damage measurement techniques are used under quasi-static conditions before to apply the procedure in dynamic. So, the well-known damage characterization by loss of stiffness technique under quasi-static loading is applied to a polypropylene. In addition, an in-situ tensile test, carried out in a microtomograph, is used to observe the cavitation phenomenon in real time. A good correlation is obtained between all these techniques and consequently the proposed technique is supposed suitable for measuring the ductile damage observed in semi-crystalline polymers under dynamic loading. By applying it to the semi-crystalline polymer at moderate and high speed loadings, the damage evolution is measured and it is observed that the damage evolution is not strain rate dependent but the failure strain on the contrary is strain rate dependent.

  9. Thoracic damage control surgery.

    Science.gov (United States)

    Gonçalves, Roberto; Saad, Roberto

    2016-01-01

    The damage control surgery came up with the philosophy of applying essential maneuvers to control bleeding and abdominal contamination in trauma patients who are within the limits of their physiological reserves. This concept was extended to thoracic injuries, where relatively simple maneuvers can shorten operative time of in extremis patients. This article aims to revise the various damage control techniques in thoracic organs that must be known to the surgeon engaged in emergency care. RESUMO A cirurgia de controle de danos surgiu com a filosofia de se aplicar manobras essenciais para controle de sangramento e contaminação abdominal, em doentes traumatizados, nos limites de suas reservas fisiológicas. Este conceito se estendeu para as lesões torácicas, onde manobras relativamente simples, podem abreviar o tempo operatório de doentes in extremis. Este artigo tem como objetivo, revisar as diversas técnicas de controle de dano em órgãos torácicos, que devem ser de conhecimento do cirurgião que atua na emergência.

  10. Incorporating damage mechanics into explosion simulation models

    International Nuclear Information System (INIS)

    Sammis, C.G.

    1993-01-01

    The source region of an underground explosion is commonly modeled as a nested series of shells. In the innermost open-quotes hydrodynamic regimeclose quotes pressures and temperatures are sufficiently high that the rock deforms as a fluid and may be described using a PVT equation of state. Just beyond the hydrodynamic regime, is the open-quotes non-linear regimeclose quotes in which the rock has shear strength but the deformation is nonlinear. This regime extends out to the open-quotes elastic radiusclose quotes beyond which the deformation is linear. In this paper, we develop a model for the non-linear regime in crystalline source rock where the nonlinearity is mostly due to fractures. We divide the non-linear regime into a open-quotes damage regimeclose quotes in which the stresses are sufficiently high to nucleate new fractures from preexisting ones and a open-quotes crack-slidingclose quotes regime where motion on preexisting cracks produces amplitude dependent attenuation and other non-linear effects, but no new cracks are nucleated. The boundary between these two regimes is called the open-quotes damage radius.close quotes The micromechanical damage mechanics recently developed by Ashby and Sammis (1990) is used to write an analytic expression for the damage radius in terms of the initial fracture spectrum of the source rock, and to develop an algorithm which may be used to incorporate damage mechanics into computer source models for the damage regime. Effects of water saturation and loading rate are also discussed

  11. Marine Environmental History

    DEFF Research Database (Denmark)

    Poulsen, Bo

    2012-01-01

    human society and natural marine resources. Within this broad topic, several trends and objectives are discernable. The essay argue that the so-called material marine environmental history has its main focus on trying to reconstruct the presence, development and environmental impact of past fisheries......This essay provides an overview of recent trends in the historiography of marine environmental history, a sub-field of environmental history which has grown tremendously in scope and size over the last c. 15 years. The object of marine environmental history is the changing relationship between...... and whaling operations. This ambition often entails a reconstruction also of how marine life has changed over time. The time frame rages from Paleolithicum to the present era. The field of marine environmental history also includes a more culturally oriented environmental history, which mainly has come...

  12. Ranking economic history journals

    DEFF Research Database (Denmark)

    Di Vaio, Gianfranco; Weisdorf, Jacob Louis

    2010-01-01

    This study ranks-for the first time-12 international academic journals that have economic history as their main topic. The ranking is based on data collected for the year 2007. Journals are ranked using standard citation analysis where we adjust for age, size and self-citation of journals. We also...... compare the leading economic history journals with the leading journals in economics in order to measure the influence on economics of economic history, and vice versa. With a few exceptions, our results confirm the general idea about what economic history journals are the most influential for economic...... history, and that, although economic history is quite independent from economics as a whole, knowledge exchange between the two fields is indeed going on....

  13. Ranking Economic History Journals

    DEFF Research Database (Denmark)

    Di Vaio, Gianfranco; Weisdorf, Jacob Louis

    This study ranks - for the first time - 12 international academic journals that have economic history as their main topic. The ranking is based on data collected for the year 2007. Journals are ranked using standard citation analysis where we adjust for age, size and self-citation of journals. We...... also compare the leading economic history journals with the leading journals in economics in order to measure the influence on economics of economic history, and vice versa. With a few exceptions, our results confirm the general idea about what economic history journals are the most influential...... for economic history, and that, although economic history is quite independent from economics as a whole, knowledge exchange between the two fields is indeed going on....

  14. Foveal damage in habitual poppers users.

    Science.gov (United States)

    Audo, Isabelle; El Sanharawi, Mohamed; Vignal-Clermont, Catherine; Villa, Antoine; Morin, Annie; Conrath, John; Fompeydie, Dominique; Sahel, José-Alain; Gocho-Nakashima, Kiyoko; Goureau, Olivier; Paques, Michel

    2011-06-01

    To describe foveal damage in habitual use of poppers, a popular recreational drug. Retrospective observational case series. Six patients with bilateral vision loss after chronic popper inhalation were seen in 4 university-based ophthalmology departments. Symptoms, medical history, ophthalmic examination, and functional and morphological tests are described. All patients experienced progressive bilateral vision loss, with central photopsia in 2 cases. Initial visual acuities ranged from 20/50 to 20/25. In all patients, a bilateral yellow foveal spot was present that, by optical coherence tomography, was associated with disruption of the outer segments of foveal cones. Functional and anatomical damage was restricted to the fovea. The poppers involved were identified as isopropyl nitrite in 3 cases. Four patients showed anatomical and/or functional improvement over several months after discontinuing popper inhalation. Repeated inhalation of poppers may be associated with prolonged bilateral vision loss due to the disruption of foveal cone outer segments. Retinal damage may progressively improve following drug discontinuation.

  15. Hydrogen damage in stainless steel

    International Nuclear Information System (INIS)

    Caskey, G.R. Jr.

    1981-01-01

    Hydrogen damage has been studied in a wide variety of stainless steels. Both internal and external hydrogen damage were evaluated by ductility or J-integral under rising tensile loads and by fractography. Analysis of the data has emphasized the potential effects of strain-induced martensite on hydrogen damage. Strain-induced martensite was neither necessary nor sufficient for hydrogen damage in the alloys studied. Neither ductility loss nor fracture-mode change correlated generally with martensite formation. Alloy composition, particularly nickel and nitrogen contents, was the primary factor in resistance to hydrogen damage. Thermomechanical processing, however, could alter the degree of hydrogen damage in an alloy and was critical for optimizing resistance to hydrogen damage. 10 figures, 10 tables

  16. Feasible Histories, Maximum Entropy

    International Nuclear Information System (INIS)

    Pitowsky, I.

    1999-01-01

    We consider the broadest possible consistency condition for a family of histories, which extends all previous proposals. A family that satisfies this condition is called feasible. On each feasible family of histories we choose a probability measure by maximizing entropy, while keeping the probabilities of commuting histories to their quantum mechanical values. This procedure is justified by the assumption that decoherence increases entropy. Finally, a criterion for identifying the nearly classical families is proposed

  17. Dependency Parsing

    CERN Document Server

    Kubler, Sandra; Nivre, Joakim

    2009-01-01

    Dependency-based methods for syntactic parsing have become increasingly popular in natural language processing in recent years. This book gives a thorough introduction to the methods that are most widely used today. After an introduction to dependency grammar and dependency parsing, followed by a formal characterization of the dependency parsing problem, the book surveys the three major classes of parsing models that are in current use: transition-based, graph-based, and grammar-based models. It continues with a chapter on evaluation and one on the comparison of different methods, and it close

  18. Cooperative Station History Forms

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Various forms, photographs and correspondence documenting the history of Cooperative station instrumentation, location changes, inspections, and...

  19. Public and popular history

    CERN Document Server

    De Groot, Jerome

    2013-01-01

    This interdisciplinary collection considers public and popular history within a global framework, seeking to understand considerations of local, domestic histories and the ways they interact with broader discourses. Grounded in particular local and national situations, the book addresses the issues associated with popular history in a globalised cultural world, such as: how the study of popular history might work in the future; new ways in which the terms 'popular' and 'public' might inform one another and nuance scholarship; transnational, intercultural models of 'pastness'; cultural translat

  20. An analysis of the development of high temperature cavitation damage

    International Nuclear Information System (INIS)

    Tinivella, R.

    1986-07-01

    The objective of the paper is the investigation of creep cavitation damage in copper. Radii distribution curves obtained from small angle neutron scattering experiments conducted on crept specimens were analyzed and compared with calculated curves. The latter were derived from cavity nucleation- and growth models. From the comparison the appropriateness of particular models can be infered. Valuable information is obtained about the nucleation behaviour. In crept and fatigued specimens, already after very short loading times, cavities appear with remarkable different radii, an observation which is contradictory to the concept of a critical radius. The analysis of the nucleation behavior emphasizes the influence of the stress dependence of the nucleation rate upon the stress dependence of damage and hence upon the stress dependence of the lifetime. In most of damage theories the latter is attributed to the stress dependency of cavity growth. A strong argument is derived in this paper in favour of the idea that both the mechanisms - growth and nucleation - contribute to the stress dependence of the lifetime. The damage development in Cu (as well as in alpha-Fe, AISI 304 and AISI 347) is compared with the prediction of the phenomenological A-model which assumes that the damage rate is proportional to the damage itself. The experiments show, that the damage increases in time slower (Cu, alpha-Fe, AISI 304) or faster (AISI 347) than predicted by the model. In copper the damage rate turns out to be constant independent of time. Accordingly the A-model is modified and the respective consequences are briefly discussed. (orig./GSCH) [de

  1. Introduction: Issues Related to Dose Units and Damage Correlation

    International Nuclear Information System (INIS)

    Stoller, Roger E.

    2012-01-01

    The observable effects of irradiation on material properties are complex and each such property changed depends sensitively on a range of irradiation and material parameters. This works against development of a universal exposure parameter. The irradiation dose to the material (both ionizing and displacement dose) can be calculated with good accuracy as long as the relevant reaction cross sections are known and implemented in the codes used. This suggests that a focus on dose calculations is warranted. When assessing damage correlation parameters, it is important to determine the appropriate dose parameter first. Then a clear distinction between damage formation and damage accumulation needs to be kept in mind. The dose unit is most helpful for estimating the primary damage generation, e.g. how damage energy is used to estimate atomic displacements. However, damage accumulation requires longer times and involves kinetic and thermodynamic processes that cannot be accounted for in a dose or primary damage unit. The adequacy of the primary damage formulations can be assessed through their use in mean field reaction rate theory or kinetic Monte Carlo microstructural evolution models to predict damage accumulation. The results of these models can be directly compared with experimental observations. (author)

  2. A history of the histories of econometrics

    NARCIS (Netherlands)

    Boumans, Marcel; Dupont-Kieffer, Ariane

    2011-01-01

    Econometricians have from the start considered historical knowledge of their own discipline as reflexive knowledge useful for delineating their discipline, that is, for setting its disciplinary boundaries with respect to its aims, its methods, and its scientific values. As such, the histories

  3. Processing of free radical damaged DNA bases

    International Nuclear Information System (INIS)

    Wallace, S.

    2003-01-01

    Free radicals produced during the radiolysis of water gives rise to a plethora of DNA damages including single strand breaks, sites of base loss and a wide variety of purine and pyrimidine base lesions. All these damages are processed in cells by base excision repair. The oxidative DNA glycosylases which catalyze the first step in the removal of a base damage during base excision repair evolved primarily to protect the cells from the deleterious mutagenic effects of single free radical-induced DNA lesions arising during oxidative metabolism. This is evidenced by the high spontaneous mutation rate in bacterial mutants lacking the oxidative DNA glycosylases. However, when a low LET photon transverses the DNA molecule, a burst of free radicals is produced during the radiolysis of water that leads to the formation of clustered damages in the DNA molecule, that are recognized by the oxidative DNA glycosylases. When substrates containing two closely opposed sugar damages or base and sugar damages are incubated with the oxidative DNA glycosylases in vitro, one strand is readily incised by the lyase activity of the DNA glycosylase. Whether or not the second strand is incised depends on the distance between the strand break resulting from the incised first strand and the remaining DNA lesion on the other strand. If the lesions are more than two or three base pairs apart, the second strand is readily cleaved by the DNA glycosylase, giving rise to a double strand break. Even if the entire base excision repair system is reconstituted in vitro, whether or not a double strand break ensues depends solely upon the ability of the DNA glycosylase to cleave the second strand. These data predicted that cells deficient in the oxidative DNA glycosylases would be radioresistant while those that overproduce an oxidative DNA glycosylase would be radiosensitive. This prediction was indeed borne in Escherichia coli that is, mutants lacking the oxidative DNA glycosylases are radioresistant

  4. Damage scenarios and an onboard support system for damaged ships

    Directory of Open Access Journals (Sweden)

    Choi Jin

    2014-06-01

    Full Text Available Although a safety assessment of damaged ships, which considers environmental conditions such as waves and wind, is important in both the design and operation phases of ships, in Korea, rules or guidelines to conduct such assessments are not yet developed. However, NATO and European maritime societies have developed guidelines for a safety assessment. Therefore, it is required to develop rules or guidelines for safety assessments such as the Naval Ship Code (NSC of NATO. Before the safety assessment of a damaged ship can be performed, the available damage scenarios must be developed and the safety assessment criteria must be established. In this paper, the parameters related to damage by accidents are identified and categorized when developing damage scenarios. The need for damage safety assessment criteria is discussed, and an example is presented. In addition, a concept and specifications for the DB-based supporting system, which is used in the operation phases, are proposed.

  5. Environmentally damaging electricity trade

    International Nuclear Information System (INIS)

    Billette de Villemeur, Etienne; Pineau, Pierre-Olivier

    2010-01-01

    Electricity trade across regions is often considered welfare enhancing. We show in this paper that this should be reconsidered if environmental externalities are taken into account. We consider two cases where trade is beneficial, before accounting for environmental damages: first, when two regions with the same technology display some demand heterogeneity; second when one region endowed with hydropower arbitrages with its 'thermal' neighbor. Our results show that under reasonable demand and supply elasticities, trade comes with an additional environmental cost. This calls for integrating environmental externalities into market reforms when redesigning the electricity sector. Two North American applications illustrate our results: trade between Pennsylvania and New York, and trade between hydro-rich Quebec and New York.

  6. Vasectomy and psychosexual damage.

    Science.gov (United States)

    Savage, P M

    1972-11-01

    The director of the Family Planning Project of the San Bernardino County (California) Health Department reviews the results of a questionnaire completed by 300 husbands and their wives 6 months to 1 year after vasectomy. The replies indicated psychosexual damage from vasectomy is virtually nonexistent. 100% of the males reported an enhanced or unchanged sense of masculinity. Vasectomy clinics have been conducted by the San Bernardino County Health Department since August 1970. More than 1000 vasectomies have been completed. Vasectomies are currently being performed at a rate of 12/week. Prevasectomy group counseling should inform couples of 1) the physiological mechanisms involved, 2) the situational nature of any psychologic changes, and 3) the probability of irreversibility of the procedure.

  7. Environmentally damaging electricity trade

    Energy Technology Data Exchange (ETDEWEB)

    Billette de Villemeur, Etienne [Toulouse School of Economics (IDEI and GREMAQ) (France); Pineau, Pierre-Olivier [HEC Montreal (Canada)

    2010-03-15

    Electricity trade across regions is often considered welfare enhancing. We show in this paper that this should be reconsidered if environmental externalities are taken into account. We consider two cases where trade is beneficial, before accounting for environmental damages: first, when two regions with the same technology display some demand heterogeneity; second when one region endowed with hydropower arbitrages with its ''thermal'' neighbor. Our results show that under reasonable demand and supply elasticities, trade comes with an additional environmental cost. This calls for integrating environmental externalities into market reforms when redesigning the electricity sector. Two North American applications illustrate our results: trade between Pennsylvania and New York, and trade between hydro-rich Quebec and New York. (author)

  8. Tactical Damage Control Resuscitation.

    Science.gov (United States)

    Fisher, Andrew D; Miles, Ethan A; Cap, Andrew P; Strandenes, Geir; Kane, Shawn F

    2015-08-01

    Recently the Committee on Tactical Combat Casualty Care changed the guidelines on fluid use in hemorrhagic shock. The current strategy for treating hemorrhagic shock is based on early use of components: Packed Red Blood Cells (PRBCs), Fresh Frozen Plasma (FFP) and platelets in a 1:1:1 ratio. We suggest that lack of components to mimic whole blood functionality favors the use of Fresh Whole Blood in managing hemorrhagic shock on the battlefield. We present a safe and practical approach for its use at the point of injury in the combat environment called Tactical Damage Control Resuscitation. We describe pre-deployment preparation, assessment of hemorrhagic shock, and collection and transfusion of fresh whole blood at the point of injury. By approaching shock with goal-directed therapy, it is possible to extend the period of survivability in combat casualties. Reprint & Copyright © 2015 Association of Military Surgeons of the U.S.

  9. [Affective dependency].

    Science.gov (United States)

    Scantamburlo, G; Pitchot, W; Ansseau, M

    2013-01-01

    Affective dependency is characterized by emotional distress (insecure attachment) and dependency to another person with a low self-esteem and reassurance need. The paper proposes a reflection on the definition of emotional dependency and the confusion caused by various denominations. Overprotective and authoritarian parenting, cultural and socio-environmental factors may contribute to the development of dependent personality. Psychological epigenetic factors, such as early socio-emotional trauma could on neuronal circuits in prefronto-limbic regions that are essential for emotional behaviour.We also focus on the interrelations between dependent personality, domestic violence and addictions. The objective for the clinician is to propose a restoration of self-esteem and therapeutic strategies focused on autonomy.

  10. Multivariate pluvial flood damage models

    International Nuclear Information System (INIS)

    Van Ootegem, Luc; Verhofstadt, Elsy; Van Herck, Kristine; Creten, Tom

    2015-01-01

    Depth–damage-functions, relating the monetary flood damage to the depth of the inundation, are commonly used in the case of fluvial floods (floods caused by a river overflowing). We construct four multivariate damage models for pluvial floods (caused by extreme rainfall) by differentiating on the one hand between ground floor floods and basement floods and on the other hand between damage to residential buildings and damage to housing contents. We do not only take into account the effect of flood-depth on damage, but also incorporate the effects of non-hazard indicators (building characteristics, behavioural indicators and socio-economic variables). By using a Tobit-estimation technique on identified victims of pluvial floods in Flanders (Belgium), we take into account the effect of cases of reported zero damage. Our results show that the flood depth is an important predictor of damage, but with a diverging impact between ground floor floods and basement floods. Also non-hazard indicators are important. For example being aware of the risk just before the water enters the building reduces content damage considerably, underlining the importance of warning systems and policy in this case of pluvial floods. - Highlights: • Prediction of damage of pluvial floods using also non-hazard information • We include ‘no damage cases’ using a Tobit model. • The damage of flood depth is stronger for ground floor than for basement floods. • Non-hazard indicators are especially important for content damage. • Potential gain of policies that increase awareness of flood risks

  11. Multivariate pluvial flood damage models

    Energy Technology Data Exchange (ETDEWEB)

    Van Ootegem, Luc [HIVA — University of Louvain (Belgium); SHERPPA — Ghent University (Belgium); Verhofstadt, Elsy [SHERPPA — Ghent University (Belgium); Van Herck, Kristine; Creten, Tom [HIVA — University of Louvain (Belgium)

    2015-09-15

    Depth–damage-functions, relating the monetary flood damage to the depth of the inundation, are commonly used in the case of fluvial floods (floods caused by a river overflowing). We construct four multivariate damage models for pluvial floods (caused by extreme rainfall) by differentiating on the one hand between ground floor floods and basement floods and on the other hand between damage to residential buildings and damage to housing contents. We do not only take into account the effect of flood-depth on damage, but also incorporate the effects of non-hazard indicators (building characteristics, behavioural indicators and socio-economic variables). By using a Tobit-estimation technique on identified victims of pluvial floods in Flanders (Belgium), we take into account the effect of cases of reported zero damage. Our results show that the flood depth is an important predictor of damage, but with a diverging impact between ground floor floods and basement floods. Also non-hazard indicators are important. For example being aware of the risk just before the water enters the building reduces content damage considerably, underlining the importance of warning systems and policy in this case of pluvial floods. - Highlights: • Prediction of damage of pluvial floods using also non-hazard information • We include ‘no damage cases’ using a Tobit model. • The damage of flood depth is stronger for ground floor than for basement floods. • Non-hazard indicators are especially important for content damage. • Potential gain of policies that increase awareness of flood risks.

  12. "Big data" in economic history.

    Science.gov (United States)

    Gutmann, Myron P; Merchant, Emily Klancher; Roberts, Evan

    2018-03-01

    Big data is an exciting prospect for the field of economic history, which has long depended on the acquisition, keying, and cleaning of scarce numerical information about the past. This article examines two areas in which economic historians are already using big data - population and environment - discussing ways in which increased frequency of observation, denser samples, and smaller geographic units allow us to analyze the past with greater precision and often to track individuals, places, and phenomena across time. We also explore promising new sources of big data: organically created economic data, high resolution images, and textual corpora.

  13. Delay-active damage versus non-local enhancement for anisotropic damage dynamics computations with alternated loading

    International Nuclear Information System (INIS)

    Desmorat, R.; Chambart, M.; Gatuingt, F.; Guilbaud, D.

    2010-01-01

    Anisotropic damage thermodynamics framework allows to model the concrete-like materials behavior and in particular their dissymmetric tension/compression response. To deal with dynamics applications such as impact, it is furthermore necessary to take into account the strain rate effect observed experimentally. This is done in the present work by means of anisotropic visco-damage, by introducing a material strain rate effect in the cases of positive hydrostatic stresses only. The proposed delay-damage law assumes no viscous effect in compression as the consideration of inertia effects proves sufficient to model the apparent material strength increase. High-rate dynamics applications imply to deal with wave propagation and reflection which can generate alternated loading in the impacted structure. In order to do so, the key concept of active damage is defined and introduced within both the damage criterion and the delay-damage evolution law. At the structural level, strain localization often leads to spurious mesh dependency. Three-dimensional Finite Element computations of dynamic tensile tests by spalling are presented, with visco-damage and either without or with non-local enhancement. Delay-damage, as introduced, regularizes the solution in fast dynamics. The location of the macro-crack initiated is found influenced by non-local regularization. The strain rate range in which each enhancement, delay-damage or non-local enhancement, has a regularizing effect is studied. (authors)

  14. Irradiation damages of semiconductor devices and their improvement

    Energy Technology Data Exchange (ETDEWEB)

    Uwatoko, Yoshiya [Saitama Univ., Urawa (Japan); Ohyama, Hidenori; Hayama, Kiyoteru; Hakata, Tetsuya; Kudou, Tomohiro

    1998-01-01

    In this study, effect of radiation on semiconductor devices was evaluated at both sides of electrical and crystalline properties for two years from 1995 fiscal years. And, damage of Si(sub 1-x)Ge(sub x) device was considered at viewpoints of Ge content and sprung-out atomic number and non ionization energy loss of constituting atom formed by radiation on its radiation source dependency of damage. This paper was a report on proton beam damage of the Si(sub 1-x)Ge(sub x) device, neutron damage of InGaAs photodiode, and effect of Ga content and kinds of beam on their damages. (G.K.)

  15. Lattice damage caused by the irradiation of diamond

    CERN Document Server

    Campbell, B; Mainwood, A; Newton, M; Davies, G

    2002-01-01

    Diamond is perceived to be radiation-hard, but the damage caused to the diamond is not well understood. The intrinsic defects (vacancies and interstitials) which are created by radiation damage are immobile at room temperature in diamond, unlike in silicon. Therefore, once the mechanisms of damage are understood for one type and energy of the particle, the dose and energy dependence of irradiation by other particles at a range of energies can be extrapolated. When a crystal is irradiated, the generation rates of vacancies and self-interstitials are generally determined by optical or electron paramagnetic resonance (EPR) spectroscopy experiments carried out after the irradiation has stopped. However, as the irradiation proceeds some of the carbon atoms displaced from their lattice sites may relax back into the vacant site, and the damage event will not be observed in the later measurement. In this paper, the mechanisms for radiation damage by charged particles in particular electrons and photons are investigat...

  16. Mechanism of cavitation damage and structure of a cavitating eddy

    International Nuclear Information System (INIS)

    Efimov, A.V.; Vorob'ev, G.A.; Filenko, Yu.I.; Petrov, K.N.

    1976-01-01

    As a result of experimental studies of the structure of a cavitating eddy and the action of single cavitation bubbles on a solid surface the assumption of double nature of cavitation damage forces depending on its regimes was made. The first type of the damage forces is shock waves, appearing around collapsing spherical bubble, the second type is hydraulic impacts of microjets making a hole in a collapsing aspherical bubble. The outward appearance of single microdents differs from each other. The damage of the first type is accompanied by corrosion. The cavitation erosion intensity of the damage of the first type exceeds that of the damage of the second type by one order of magnitude. The values of the porosity of a cavitation eddy, the bubble concentration and the distance between them, the bubble distribution according to the size and the form for the initial cavitation stage are given from holographic investigations

  17. History of Mathematics

    DEFF Research Database (Denmark)

    Hansen, Vagn Lundsgaard; Gray, Jeremy

    Volume 1 in Theme on "History of Mathematics", in "Encyclopedia of Life Support Systems (EOLSS), developed under the auspices of the UNESCO.......Volume 1 in Theme on "History of Mathematics", in "Encyclopedia of Life Support Systems (EOLSS), developed under the auspices of the UNESCO....

  18. Business history and risk

    OpenAIRE

    Terry Gourvish

    2003-01-01

    CARR, in association with the Centre for Business History, University of Leeds, held a successful workshop on 'Business History and Risk' on 20 February 2002. The workshop, which was sponsored by the ESRC, brought together business historians, economists, accountants and risk analysts to develop an interdisciplinary discussion on understandings of risk by employers, workers and governments in different historical settings.

  19. Aggersborg through history

    DEFF Research Database (Denmark)

    Roesdahl, Else

    2014-01-01

    Aggersborg's history from the time of the end of the circular fortress till the present day, with a focus on the late Viking Age and the Middle Ages......Aggersborg's history from the time of the end of the circular fortress till the present day, with a focus on the late Viking Age and the Middle Ages...

  20. The Two World Histories

    Science.gov (United States)

    Dunn, Ross E.

    2008-01-01

    In the arenas where the two world histories have taken shape, educators vigorously debate among themselves intellectual, pedagogical, and policy issues surrounding world history as a school subject. The people in each arena tend to share, despite internal disagreements, a common set of premises and assumptions for ordering the discussion of world…